[gcc-6] 116/401: - update NEWS files
Ximin Luo
infinity0 at debian.org
Wed Apr 5 15:48:10 UTC 2017
This is an automated email from the git hooks/post-receive script.
infinity0 pushed a commit to branch pu/reproducible_builds
in repository gcc-6.
commit 4deeba6ae4ffe871d6220bc4f807667fe26571f5
Author: doko <doko at 6ca36cf4-e1d1-0310-8c6f-e303bb2178ca>
Date: Wed Apr 27 11:46:37 2016 +0000
- update NEWS files
git-svn-id: svn://anonscm.debian.org/gcccvs/branches/sid/gcc-6@8792 6ca36cf4-e1d1-0310-8c6f-e303bb2178ca
---
debian/NEWS.gcc | 15955 ++---------------------------------------------------
debian/NEWS.html | 1466 +++--
2 files changed, 1225 insertions(+), 16196 deletions(-)
diff --git a/debian/NEWS.gcc b/debian/NEWS.gcc
index 409baf2..11e6954 100644
--- a/debian/NEWS.gcc
+++ b/debian/NEWS.gcc
@@ -5,21 +5,21 @@ that led to GCC 3. For information on GCC 2.8.1 and older releases of GCC 2,
see ONEWS.
======================================================================
-http://gcc.gnu.org/gcc-5/index.html
- GCC 5 Release Series
+http://gcc.gnu.org/gcc-6/index.html
+ GCC 6 Release Series
- April 22, 2015
+ April 27, 2015
The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 5.1.
+ release of GCC 6.1.
This release is a major release, containing new features (as well as
- many other improvements) relative to GCC 4.9.x.
+ many other improvements) relative to GCC 5.x.
Release History
- GCC 5.1
- April 22, 2015 ([2]changes, [3]documentation)
+ GCC 6.1
+ April 27, 2015 ([2]changes, [3]documentation)
References and Acknowledgements
@@ -53,14 +53,14 @@ References and Acknowledgements
provided this notice is preserved.
These pages are [15]maintained by the GCC team. Last modified
- 2015-04-22[16].
+ 2016-04-27[16].
References
1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-5/changes.html
- 3. http://gcc.gnu.org/onlinedocs/5.1.0/
- 4. http://gcc.gnu.org/gcc-5/buildstat.html
+ 2. http://gcc.gnu.org/gcc-6/changes.html
+ 3. http://gcc.gnu.org/onlinedocs/6.1.0/
+ 4. http://gcc.gnu.org/gcc-6/buildstat.html
5. http://gcc.gnu.org/onlinedocs/gcc/Contributors.html
6. http://gcc.gnu.org/index.html
7. mailto:gcc at gcc.gnu.org
@@ -74,15477 +74,634 @@ References
15. https://gcc.gnu.org/about.html
16. http://validator.w3.org/check/referer
======================================================================
-http://gcc.gnu.org/gcc-5/changes.html
- GCC 5 Release Series
+http://gcc.gnu.org/gcc-6/changes.html
+ GCC 6 Release Series
Changes, New Features, and Fixes
-Caveats
-
- * The default mode for C is now -std=gnu11 instead of -std=gnu89.
- * The C++ runtime library (libstdc++) uses a new ABI by default (see
- [1]below).
- * The Graphite framework for loop optimizations no longer requires
- the CLooG library, only ISL version 0.14 (recommended) or 0.12.2.
- The installation manual contains more information about
- requirements to build GCC.
- * The non-standard C++0x type traits has_trivial_default_constructor,
- has_trivial_copy_constructor and has_trivial_copy_assign have been
- deprecated and will be removed in a future version. The standard
- C++11 traits is_trivially_default_constructible,
- is_trivially_copy_constructible and is_trivially_copy_assignable
- should be used instead.
-
-General Optimizer Improvements
-
- * Inter-procedural optimization improvements:
- + An Identical Code Folding (ICF) pass (controlled via
- -fipa-icf) has been added. Compared to the identical code
- folding performed by the Gold linker this pass does not
- require function sections. It also performs merging before
- inlining, so inter-procedural optimizations are aware of the
- code re-use. On the other hand not all unifications performed
- by a linker are doable by GCC which must honor aliasing
- information. During link-time optimization of Firefox, this
- pass unifies about 31000 functions, that is 14% overall.
- + The devirtualization pass was significantly improved by adding
- better support for speculative devirtualization and dynamic
- type detection. About 50% of virtual calls in Firefox are now
- speculatively devirtualized during link-time optimization.
- + A new comdat localization pass allows the linker to eliminate
- more dead code in presence of C++ inline functions.
- + Virtual tables are now optimized. Local aliases are used to
- reduce dynamic linking time of C++ virtual tables on ELF
- targets and data alignment has been reduced to limit data
- segment bloat.
- + A new -fno-semantic-interposition option can be used to
- improve code quality of shared libraries where interposition
- of exported symbols is not allowed.
- + Write-only variables are now detected and optimized out.
- + With profile feedback the function inliner can now bypass
- --param inline-insns-auto and --param inline-insns-single
- limits for hot calls.
- + The IPA reference pass was significantly sped up making it
- feasible to enable -fipa-reference with -fprofile-generate.
- This also solves a bottleneck seen when building Chromium with
- link-time optimization.
- + The symbol table and call-graph API was reworked to C++ and
- simplified.
- + The interprocedural propagation of constants now also
- propagates alignments of pointer parameters. This for example
- means that the vectorizer often does not need to generate loop
- prologues and epilogues to make up for potential
- misalignments.
- * Link-time optimization improvements:
- + One Definition Rule based merging of C++ types has been
- implemented. Type merging enables better devirtualization and
- alias analysis. Streaming extra information needed to merge
- types adds about 2-6% of memory size and object size increase.
- This can be controlled by -flto-odr-type-merging.
- + Command-line optimization and target options are now streamed
- on a per-function basis and honored by the link-time
- optimizer. This change makes link-time optimization a more
- transparent replacement of per-file optimizations. It is now
- possible to build projects that require different optimization
- settings for different translation units (such as -ffast-math,
- -mavx, or -finline). Contrary to earlier GCC releases, the
- optimization and target options passed on the link command
- line are ignored.
- Note that this applies only to those command-line options that
- can be passed to optimize and target attributes. Command-line
- options affecting global code generation (such as -fpic),
- warnings (such as -Wodr), optimizations affecting the way
- static variables are optimized (such as -fcommon), debug
- output (such as -g), and --param parameters can be applied
- only to the whole link-time optimization unit. In these cases,
- it is recommended to consistently use the same options at both
- compile time and link time.
- + GCC bootstrap now uses slim LTO object files.
- + Memory usage and link times were improved. Tree merging was
- sped up, memory usage of GIMPLE declarations and types was
- reduced, and, support for on-demand streaming of variable
- constructors was added.
- * Feedback directed optimization improvements:
- + A new auto-FDO mode uses profiles collected by low overhead
- profiling tools (perf) instead of more expensive program
- instrumentation (via -fprofile-generate). SPEC2006 benchmarks
- on x86-64 improve by 4.7% with auto-FDO and by 7.3% with
- traditional feedback directed optimization.
- + Profile precision was improved in presence of C++ inline and
- extern inline functions.
- + The new gcov-tool utility allows manipulating profiles.
- + Profiles are now more tolerant to source file changes (this
- can be controlled by --param profile-func-internal-id).
- * Register allocation improvements:
- + A new local register allocator (LRA) sub-pass, controlled by
- -flra-remat, implements control-flow sensitive global register
- rematerialization. Instead of spilling and restoring a
- register value, it is recalculated if it is profitable. The
- sub-pass improved SPEC2000 generated code by 1% and 0.5%
- correspondingly on ARM and x86-64.
- + Reuse of the PIC hard register, instead of using a fixed
- register, was implemented on x86/x86-64 targets. This improves
- generated PIC code performance as more hard registers can be
- used. Shared libraries can significantly benefit from this
- optimization. Currently it is switched on only for x86/x86-64
- targets. As RA infrastructure is already implemented for PIC
- register reuse, other targets might follow this in the future.
- + A simple form of inter-procedural RA was implemented. When it
- is known that a called function does not use caller-saved
- registers, save/restore code is not generated around the call
- for such registers. This optimization can be controlled by
- -fipa-ra
- + LRA is now much more effective at generating spills of general
- registers into vector registers instead of memory on
- architectures (e.g., modern Intel processors) where this is
- profitable.
- * UndefinedBehaviorSanitizer gained a few new sanitization options:
- + -fsanitize=float-divide-by-zero: detect floating-point
- division by zero;
- + -fsanitize=float-cast-overflow: check that the result of
- floating-point type to integer conversions do not overflow;
- + -fsanitize=bounds: enable instrumentation of array bounds and
- detect out-of-bounds accesses;
- + -fsanitize=alignment: enable alignment checking, detect
- various misaligned objects;
- + -fsanitize=object-size: enable object size checking, detect
- various out-of-bounds accesses.
- + -fsanitize=vptr: enable checking of C++ member function calls,
- member accesses and some conversions between pointers to base
- and derived classes, detect if the referenced object does not
- have the correct dynamic type.
- * Pointer Bounds Checker, a bounds violation detector, has been added
- and can be enabled via -fcheck-pointer-bounds. Memory accesses are
- instrumented with run-time checks of used pointers against their
- bounds to detect pointer bounds violations (overflows). The Pointer
- Bounds Checker is available on x86/x86-64 GNU/Linux targets with a
- new ISA extension Intel MPX support. See the Pointer Bounds Checker
- [2]Wiki page for more details.
-
-New Languages and Language specific improvements
-
- * [3]OpenMP 4.0 specification offloading features are now supported
- by the C, C++, and Fortran compilers. Generic changes:
- + Infrastructure (suitable for any vendor).
- + Testsuite which covers offloading from the [4]OpenMP 4.0
- Examples document.
- Specific for upcoming Intel Xeon Phi products:
- + Run-time library.
- + Card emulator.
- * GCC 5 includes a preliminary implementation of the OpenACC 2.0a
- specification. OpenACC is intended for programming accelerator
- devices such as GPUs. See [5]the OpenACC wiki page for more
- information.
-
- C family
-
- * The default setting of the -fdiagnostics-color= command-line option
- is now [6]configurable when building GCC using configuration option
- --with-diagnostics-color=. The possible values are: never, always,
- auto and auto-if-env. The new default auto uses color only when the
- standard error is a terminal. The default in GCC 4.9 was
- auto-if-env, which is equivalent to auto if there is a non-empty
- GCC_COLORS environment variable, and never otherwise. As in GCC
- 4.9, an empty GCC_COLORS variable in the environment will always
- disable colors, no matter what the default is or what command-line
- options are used.
- * A new command-line option -Wswitch-bool has been added for the C
- and C++ compilers, which warns whenever a switch statement has an
- index of boolean type.
- * A new command-line option -Wlogical-not-parentheses has been added
- for the C and C++ compilers, which warns about "logical not" used
- on the left hand side operand of a comparison.
- * A new command-line option -Wsizeof-array-argument has been added
- for the C and C++ compilers, which warns when the sizeof operator
- is applied to a parameter that has been declared as an array in a
- function definition.
- * A new command-line option -Wbool-compare has been added for the C
- and C++ compilers, which warns about boolean expressions compared
- with an integer value different from true/false.
- * Full support for [7]Cilk Plus has been added to the GCC compiler.
- Cilk Plus is an extension to the C and C++ languages to support
- data and task parallelism.
- * A new attribute no_reorder prevents reordering of selected symbols
- against other such symbols or inline assembler. This enables to
- link-time optimize the Linux kernel without having to resort to
- -fno-toplevel-reorder that disables several optimizations.
- * New preprocessor constructs, __has_include and __has_include_next,
- to test the availability of headers have been added.
- This demonstrates a way to include the header <optional> only if it
- is available:
-
-#ifdef __has_include
-# if __has_include(<optional>)
-# include <optional>
-# define have_optional 1
-# elif __has_include(<experimental/optional>)
-# include <experimental/optional>
-# define have_optional 1
-# define experimental_optional
-# else
-# define have_optional 0
-# endif
-#endif
-
- The header search paths for __has_include and __has_include_next
- are equivalent to those of the standard directive #include and the
- extension #include_next respectively.
- * A new built-in function-like macro to determine the existence of an
- attribute, __has_attribute, has been added. The equivalent built-in
- macro __has_cpp_attribute was added to C++ to support
- [8]Feature-testing recommendations for C++. The macro
- __has_attribute is added to all C-like languages as an extension:
-
-int
-#ifdef __has_attribute
-# if __has_attribute(__noinline__)
- __attribute__((__noinline__))
-# endif
-#endif
-foo(int x);
-
- If an attribute exists, a nonzero constant integer is returned. For
- standardized C++ attributes a date is returned, otherwise the
- constant returned is 1. Both __has_attribute and
- __has_cpp_attribute will add underscores to an attribute name if
- necessary to resolve the name. For C++11 and onwards the attribute
- may be scoped.
- * A new set of built-in functions for arithmetics with overflow
- checking has been added: __builtin_add_overflow,
- __builtin_sub_overflow and __builtin_mul_overflow and for
- compatibility with clang also other variants. These builtins have
- two integral arguments (which don't need to have the same type),
- the arguments are extended to infinite precision signed type, +, -
- or * is performed on those, and the result is stored in an integer
- variable pointed to by the last argument. If the stored value is
- equal to the infinite precision result, the built-in functions
- return false, otherwise true. The type of the integer variable that
- will hold the result can be different from the types of the first
- two arguments. The following snippet demonstrates how this can be
- used in computing the size for the calloc function:
-
-void *
-calloc (size_t x, size_t y)
-{
- size_t sz;
- if (__builtin_mul_overflow (x, y, &sz))
- return NULL;
- void *ret = malloc (sz);
- if (ret) memset (res, 0, sz);
- return ret;
-}
-
- On e.g. i?86 or x86-64 the above will result in a mul instruction
- followed by a jump on overflow.
- * The option -fextended-identifiers is now enabled by default for
- C++, and for C99 and later C versions. Various bugs in the
- implementation of extended identifiers have been fixed.
-
- C
-
- * The default mode has been changed to -std=gnu11.
- * A new command-line option -Wc90-c99-compat has been added to warn
- about features not present in ISO C90, but present in ISO C99.
- * A new command-line option -Wc99-c11-compat has been added to warn
- about features not present in ISO C99, but present in ISO C11.
- * It is possible to disable warnings about conversions between
- pointers that have incompatible types via a new warning option
- -Wno-incompatible-pointer-types; warnings about implicit
- incompatible integer to pointer and pointer to integer conversions
- via a new warning option -Wno-int-conversion; and warnings about
- qualifiers on pointers being discarded via a new warning option
- -Wno-discarded-qualifiers.
- * To allow proper use of const qualifiers with multidimensional
- arrays, GCC will not warn about incompatible pointer types anymore
- for conversions between pointers to arrays with and without const
- qualifier (except when using -pedantic). Instead, a new warning is
- emitted only if the const qualifier is lost. This can be controlled
- with a new warning option -Wno-discarded-array-qualifiers.
- * The C front end now generates more precise caret diagnostics.
- * The -pg command-line option now only affects the current file in an
- LTO build.
-
- C++
-
- * G++ now supports [9]C++14 variable templates.
- * -Wnon-virtual-dtor doesn't warn anymore for final classes.
- * Excessive template instantiation depth is now a fatal error. This
- prevents excessive diagnostics that usually do not help to identify
- the problem.
- * G++ and libstdc++ now implement the feature-testing macros from
- [10]Feature-testing recommendations for C++.
- * G++ now allows typename in a template template parameter.
-
-template<template<typename> typename X> struct D; // OK
-
- * G++ now supports [11]C++14 aggregates with non-static data member
- initializers.
-
-struct A { int i, j = i; };
-A a = { 42 }; // a.j is also 42
-
- * G++ now supports [12]C++14 extended constexpr.
-
-constexpr int f (int i)
-{
- int j = 0;
- for (; i > 0; --i)
- ++j;
- return j;
-}
-
-constexpr int i = f(42); // i is 42
-
- * G++ now supports the [13]C++14 sized deallocation functions.
-
-void operator delete (void *, std::size_t) noexcept;
-void operator delete[] (void *, std::size_t) noexcept;
-
- * A new One Definition Rule violation warning (controlled by -Wodr)
- detects mismatches in type definitions and virtual table contents
- during link-time optimization.
- * New warnings -Wsuggest-final-types and -Wsuggest-final-methods help
- developers to annotate programs with final specifiers (or anonymous
- namespaces) to improve code generation. These warnings can be used
- at compile time, but they are more useful in combination with
- link-time optimization.
- * G++ no longer supports [14]N3639 variable length arrays, as they
- were removed from the C++14 working paper prior to ratification.
- GNU VLAs are still supported, so VLA support is now the same in
- C++14 mode as in C++98 and C++11 modes.
- * G++ now allows passing a non-trivially-copyable class via C
- varargs, which is conditionally-supported with
- implementation-defined semantics in the standard. This uses the
- same calling convention as a normal value parameter.
- * G++ now defaults to -fabi-version=0 and -fabi-compat-version=2. So
- various mangling bugs are fixed, but G++ will still emit aliases
- with the old, wrong mangling where feasible. -Wabi continues to
- warn about differences.
-
- Runtime Library (libstdc++)
-
- * A [15]Dual ABI is provided by the library. A new ABI is enabled by
- default. The old ABI is still supported and can be used by defining
- the macro _GLIBCXX_USE_CXX11_ABI to 0 before including any C++
- standard library headers.
- * A new implementation of std::string is enabled by default, using
- the small string optimization instead of copy-on-write reference
- counting.
- * A new implementation of std::list is enabled by default, with an
- O(1) size() function;
- * [16]Full support for C++11, including the following new features:
- + std::deque and std::vector<bool> meet the allocator-aware
- container requirements;
- + movable and swappable iostream classes;
- + support for std::align and std::aligned_union;
- + type traits std::is_trivially_copyable,
- std::is_trivially_constructible, std::is_trivially_assignable
- etc.;
- + I/O manipulators std::put_time, std::get_time, std::hexfloat
- and std::defaultfloat;
- + generic locale-aware std::isblank;
- + locale facets for Unicode conversion;
- + atomic operations for std::shared_ptr;
- + std::notify_all_at_thread_exit() and functions for making
- futures ready at thread exit.
- * Support for the C++11 hexfloat manipulator changes how the num_put
- facet formats floating point types when
- ios_base::fixed|ios_base::scientific is set in a stream's fmtflags.
- This change affects all language modes, even though the C++98
- standard gave no special meaning to that combination of flags. To
- prevent the use of hexadecimal notation for floating point types
- use str.unsetf(std::ios_base::floatfield) to clear the relevant
- bits in str.flags().
- * [17]Full experimental support for C++14, including the following
- new features:
- + std::is_final type trait;
- + heterogeneous comparison lookup in associative containers.
- + global functions cbegin, cend, rbegin, rend, crbegin, and
- crend for range access to containers, arrays and initializer
- lists.
- * [18]Improved experimental support for the Library Fundamentals TS,
- including:
- + class std::experimental::any;
- + function template std::experimental::apply;
- + function template std::experimental::sample;
- + function template std::experimental::search and related
- searcher types;
- + variable templates for type traits;
- + function template std::experimental::not_fn.
- * New random number distributions logistic_distribution and
- uniform_on_sphere_distribution as extensions.
- * [19]GDB Xmethods for containers and std::unique_ptr.
-
- Fortran
-
- * Compatibility notice:
- + The version of the module files (.mod) has been incremented.
- + For free-form source files, [20]-Werror=line-truncation is now
- enabled by default; note that comments exceeding the line
- length are not diagnosed. (For fixed-form source code, the
- same warning is available but turned off by default, such that
- excess characters are ignored. -ffree-line-length-n and
- -ffixed-line-length-n can be used to modify the default line
- lengths of 132 and 72 columns, respectively.)
- + The -Wtabs option is now more sensible: with -Wtabs the
- compiler warns if it encounters tabs and with -Wno-tabs this
- warning is turned off. Before, -Wno-tabs warned and -Wtabs
- turned the warning off. As before, the warning is also enabled
- by -Wall, -pedantic and the f95, f2003, f2008 and f2008ts
- options of -std=.
- * Incomplete support for colorizing diagnostics emitted by gfortran
- has been added. The option [21]-fdiagnostics-color controls when
- color is used in diagnostics. The default value of this option can
- be [22]configured when building GCC. The GCC_COLORS environment
- variable can be used to customize the colors or disable coloring
- completely. Sample diagnostics output:
- $ gfortran -fdiagnostics-color=always -Wuse-without-only test.f90
- test.f90:6:1:
-
- 0 continue
- 1
- Error: Zero is not a valid statement label at (1)
- test.f90:9:6:
-
- USE foo
- 1
- Warning: USE statement at (1) has no ONLY qualifier [-Wuse-without-only]
-
- * The -Wuse-without-only option has been added to warn when a USE
- statement has no ONLY qualifier and, thus, implicitly imports all
- public entities of the used module.
- * Formatted READ and WRITE statements now work correctly in
- locale-aware programs. For more information and potential caveats,
- see [23]Section 5.3 Thread-safety of the runtime library in the
- manual.
- * [24]Fortran 2003:
- + The intrinsic IEEE modules (IEEE_FEATURES, IEEE_EXCEPTIONS and
- IEEE_ARITHMETIC) are now supported.
- * [25]Fortran 2008:
- + [26]Coarrays: Full experimental support of Fortran 2008's
- coarrays with -fcoarray=lib except for allocatable/pointer
- components of derived-type coarrays. GCC currently only ships
- with a single-image library (libcaf_single), but multi-image
- support based on MPI and GASNet is provided by the libraries
- of the [27]OpenCoarrays project.
- * TS18508 Additional Parallel Features in Fortran:
- + Support for the collective intrinsic subroutines CO_MAX,
- CO_MIN, CO_SUM, CO_BROADCAST and CO_REDUCE has been added,
- including -fcoarray=lib support.
- + Support for the new atomic intrinsics has been added,
- including -fcoarray=lib support.
- * Fortran 2015:
- + Support for IMPLICIT NONE (external, type).
- + ERROR STOP is now permitted in pure procedures.
-
- Go
-
- * GCC 5 provides a complete implementation of the Go 1.4.2 release.
- * Building GCC 5 with Go enabled will install two new programs:
- [28]go and [29]gofmt.
-
-libgccjit
-
- New in GCC 5 is the ability to build GCC as a shared library for
- embedding in other processes (such as interpreters), suitable for
- Just-In-Time compilation to machine code.
-
- The shared library has a [30]C API and a [31]C++ wrapper API providing
- some "syntactic sugar". There are also bindings available from 3rd
- parties for [32]Python and for [33]D.
-
- For example, this library can be used by interpreters for [34]compiling
- functions from bytecode to machine code.
-
- The library can also be used for ahead-of-time compilation, enabling
- GCC to be plugged into a pre-existing frontend. An example of using
- this to build a compiler for an esoteric language we'll refer to as
- "brainf" can be seen [35]here.
-
- libgccjit is licensed under the GPLv3 (or at your option, any later
- version)
-
- It should be regarded as experimental at this time.
-
-New Targets and Target Specific Improvements
-
- AArch64
-
- * Code generation for the ARM Cortex-A57 processor has been improved.
- A more accurate instruction scheduling model for the processor is
- now used, and a number of compiler tuning parameters have been set
- to offer increased performance when compiling with -mcpu=cortex-a57
- or -mtune=cortex-a57.
- * A workaround for the ARM Cortex-A53 erratum 835769 has been added
- and can be enabled by giving the -mfix-cortex-a53-835769 option.
- Alternatively it can be enabled by default by configuring GCC with
- the --enable-fix-cortex-a53-835769 option.
- * The optional cryptographic extensions to the ARMv8-A architecture
- are no longer enabled by default when specifying the
- -mcpu=cortex-a53, -mcpu=cortex-a57 or -mcpu=cortex-a57.cortex-a53
- options. To enable these extensions add +crypto to the value of
- -mcpu or -march e.g. -mcpu=cortex-a53+crypto.
- * Support has been added for the following processors (GCC
- identifiers in parentheses): ARM Cortex-A72 (cortex-a72) and
- initial support for its big.LITTLE combination with the ARM
- Cortex-A53 (cortex-a72.cortex-a53), Cavium ThunderX (thunderx),
- Applied Micro X-Gene 1 (xgene1), and Samsung Exynos M1 (exynos-m1).
- The GCC identifiers can be used as arguments to the -mcpu or -mtune
- options, for example: -mcpu=xgene1 or -mtune=cortex-a72.cortex-a53.
- Using -mcpu=cortex-a72 requires a version of GNU binutils that has
- support for the Cortex-A72.
- * The transitional options -mlra and -mno-lra have been removed. The
- AArch64 backend now uses the local register allocator (LRA) only.
-
- ARM
-
- * Thumb-1 assembly code is now generated in unified syntax. The new
- option -masm-syntax-unified specifies whether inline assembly code
- is using unified syntax. By default the option is off which means
- non-unified syntax is used. However this is subject to change in
- future releases. Eventually the non-unified syntax will be
- deprecated.
- * It is now a configure-time error to use the --with-cpu configure
- option with either of --with-tune or --with-arch.
- * Code generation for the ARM Cortex-A57 processor has been improved.
- A more accurate instruction scheduling model for the processor is
- now used, and a number of compiler tuning parameters have been set
- to offer increased performance when compiling with -mcpu=cortex-a57
- or -mtune=cortex-a57.
- * Support has been added for the following processors (GCC
- identifiers in parentheses): ARM Cortex-A17 (cortex-a17) and
- initial support for its big.LITTLE combination with the ARM
- Cortex-A7 (cortex-a17.cortex-a7), ARM Cortex-A72 (cortex-a72) and
- initial support for its big.LITTLE combination with the ARM
- Cortex-A53 (cortex-a72.cortex-a53), ARM Cortex-M7 (cortex-m7),
- Applied Micro X-Gene 1 (xgene1), and Samsung Exynos M1 (exynos-m1).
- The GCC identifiers can be used as arguments to the -mcpu or -mtune
- options, for example: -mcpu=xgene1 or -mtune=cortex-a72.cortex-a53.
- Using -mcpu=cortex-a72 requires a version of GNU binutils that has
- support for the Cortex-A72.
- * The deprecated option -mwords-little-endian has been removed.
- * The options -mapcs, -mapcs-frame, -mtpcs-frame and
- -mtpcs-leaf-frame which are only applicable to the old ABI have
- been deprecated.
- * The transitional options -mlra and -mno-lra have been removed. The
- ARM backend now uses the local register allocator (LRA) only.
-
- IA-32/x86-64
-
- * New ISA extensions support [36]AVX-512{BW,DQ,VL,IFMA,VBMI} of
- Intel's CPU codenamed Skylake Server was added to GCC. That
- includes inline assembly support, new intrinsics, and basic
- autovectorization. These new AVX-512 extensions are available via
- the following GCC switches: AVX-512 Vector Length EVEX feature:
- -mavx512vl, AVX-512 Byte and Word instructions: -mavx512bw, AVX-512
- Dword and Qword instructions: -mavx512dq, AVX-512 FMA-52
- instructions: -mavx512ifma and for AVX-512 Vector Bit Manipulation
- Instructions: -mavx512vbmi.
- * New ISA extensions support [37]Intel MPX was added to GCC. This new
- extension is available via the -mmpx compiler switch. Intel MPX is
- a set of processor features which, with compiler, run-time library
- and OS support, brings increased robustness to software by run-time
- checking pointer references against their bounds. In GCC Intel MPX
- is supported by Pointer Bounds Checker and libmpx run-time
- libraries.
- * The new -mrecord-mcount option for -pg generates a Linux kernel
- style table of pointers to mcount or __fentry__ calls at the
- beginning of functions. The new -mnop-mcount option in addition
- also generates nops in place of the __fentry__ or mcount call, so
- that a call per function can be later patched in. This can be used
- for low overhead tracing or hot code patching.
- * The new -malign-data option controls how GCC aligns variables.
- -malign-data=compat uses increased alignment compatible with GCC
- 4.8 and earlier, -malign-data=abi uses alignment as specified by
- the psABI, and -malign-data=cacheline uses increased alignment to
- match the cache line size. -malign-data=compat is the default.
- * The new -mskip-rax-setup option skips setting up the RAX register
- when SSE is disabled and there are no variable arguments passed in
- vector registers. This can be used to optimize the Linux kernel.
-
- MIPS
-
- * MIPS Releases 3 and 5 are now directly supported. Use the
- command-line options -mips32r3, -mips64r3, -mips32r5 and -mips64r5
- to enable code-generation for these processors.
- * The Imagination P5600 processor is now supported using the
- -march=p5600 command-line option.
- * The Cavium Octeon3 processor is now supported using the
- -march=octeon3 command-line option.
- * MIPS Release 6 is now supported using the -mips32r6 and -mips64r6
- command-line options.
- * The o32 ABI has been modified and extended. The o32 64-bit
- floating-point register support is now obsolete and has been
- removed. It has been replaced by three ABI extensions FPXX, FP64A,
- and FP64. The meaning of the -mfp64 command-line option has
- changed. It is now used to enable the FP64A and FP64 ABI
- extensions.
- + The FPXX extension requires that code generated to access
- double-precision values use even-numbered registers. Code that
- adheres to this extension is link-compatible with all other
- o32 double-precision ABI variants and will execute correctly
- in all hardware FPU modes. The command-line options -mabi=32
- -mfpxx can be used to enable this extension. MIPS II is the
- minimum processor required.
- + The o32 FP64A extension requires that floating-point registers
- be 64-bit and odd-numbered single-precision registers are not
- allowed. Code that adheres to the o32 FP64A variant is
- link-compatible with all other o32 double-precision ABI
- variants. The command-line options -mabi=32 -mfp64
- -mno-odd-spreg can be used to enable this extension. MIPS32R2
- is the minimum processor required.
- + The o32 FP64 extension also requires that floating-point
- registers be 64-bit, but permits the use of single-precision
- registers. Code that adheres to the o32 FP64 variant is
- link-compatible with o32 FPXX and o32 FP64A variants only,
- i.e. it is not compatible with the original o32
- double-precision ABI. The command-line options -mabi=32 -mfp64
- -modd-spreg can be used to enable this extension. MIPS32R2 is
- the minimum processor required.
- The new ABI variants can be enabled by default using the configure
- time options --with-fp-32=[32|xx|64] and --with(out)-odd-sp-reg-32.
- It is strongly recommended that all vendors begin to set o32 FPXX
- as the default ABI. This will be required to run the generated code
- on MIPSR5 cores in conjunction with future MIPS SIMD (MSA) code and
- MIPSR6 cores.
- * GCC will now pass all floating-point options to the assembler if
- GNU binutils 2.25 is used. As a result, any inline assembly code
- that uses hard-float instructions should be amended to include a
- .set directive to override the global assembler options when
- compiling for soft-float targets.
-
- NDS32
-
- * The variadic function ABI implementation is now compatible with
- past Andes toolchains where the caller uses registers to pass
- arguments and the callee is in charge of pushing them on stack.
- * The options -mforce-fp-as-gp, -mforbid-fp-as-gp, and -mex9 have
- been removed since they are not yet available in the nds32 port of
- GNU binutils.
- * A new option -mcmodel=[small|medium|large] supports varied code
- models on code generation. The -mgp-direct option became
- meaningless and can be discarded.
-
- RX
-
- * A new command line option -mno-allow-string-insns can be used to
- disable the generation of the SCMPU, SMOVU, SMOVB, SMOVF, SUNTIL,
- SWHILE and RMPA instructions. An erratum released by Renesas shows
- that it is unsafe to use these instructions on addresses within the
- I/O space of the processor. The new option can be used when the
- programmer is concerned that the I/O space might be accessed. The
- default is still to enable these instructions.
-
- SH
-
- * The compiler will now pass the appropriate --isa= option to the
- assembler.
- * The default handling for the GBR has been changed from call
- clobbered to call preserved. The old behavior can be reinstated by
- specifying the option -fcall-used-gbr.
- * Support for the SH4A fpchg instruction has been added which will be
- utilized when switching between single and double precision FPU
- modes.
- * The compiler no longer uses the __fpscr_values array for switching
- between single and double FPU precision modes on non-SH4A targets.
- Instead mode switching will now be performed by storing, modifying
- and reloading the FPSCR, so that other FPSCR bits are preserved
- across mode switches. The __fpscr_values array that is defined in
- libgcc is still present for backwards compatibility, but it will
- not be referenced by compiler generated code anymore.
- * New builtin functions __builtin_sh_get_fpscr and
- __builtin_sh_set_fpscr have been added. The __builtin_sh_set_fpscr
- function will mask the specified bits in such a way that the SZ, PR
- and FR mode bits will be preserved, while changing the other bits.
- These new functions do not reference the __fpscr_values array. The
- old functions __set_fpscr and __get_fpscr in libgcc which access
- the __fpscr_values array are still present for backwards
- compatibility, but their usage is highly discouraged.
- * Some improvements to code generated for __atomic built-in
- functions.
- * When compiling for SH2E the compiler will no longer force the usage
- of delay slots for conditional branch instructions bt and bf. The
- old behavior can be reinstated (e.g. to work around a hardware bug
- in the original SH7055) by specifying the new option
- -mcbranch-force-delay-slot.
-
-Operating Systems
-
- DragonFly BSD
-
- * GCC now supports the DragonFly BSD operating system.
-
- FreeBSD
-
- * GCC now supports the FreeBSD operating system for the arm port
- through the arm*-*-freebsd* target triplets.
-
- VxWorks MILS
-
- * GCC now supports the MILS (Multiple Independent Levels of Security)
- variant of WindRiver's VxWorks operating system for PowerPC
- targets.
-
-Other significant improvements
-
- * The gcc-ar, gcc-nm, gcc-ranlib wrappers now understand a -B option
- to set the compiler to use.
-
- * When the new command-line option -freport-bug is used, GCC
- automatically generates a developer-friendly reproducer whenever an
- internal compiler error is encountered.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [38]GCC manuals. If that fails, the
- [39]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [40]gcc at gcc.gnu.org. All of [41]our lists have public
- archives.
-
- Copyright (C) [42]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [43]maintained by the GCC team. Last modified
- 2015-04-22[44].
-
-References
-
- 1. http://gcc.gnu.org/gcc-5/changes.html#libstdcxx
- 2. https://gcc.gnu.org/wiki/Intel MPX support in the GCC compiler
- 3. http://www.openmp.org/mp-documents/OpenMP4.0.0.pdf
- 4. http://openmp.org/mp-documents/OpenMP4.0.0.Examples.pdf
- 5. https://gcc.gnu.org/wiki/OpenACC
- 6. https://gcc.gnu.org/install/configure.html
- 7. https://www.cilkplus.org/
- 8. http://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations
- 9. http://gcc.gnu.org/projects/cxx1y.html
- 10. http://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations
- 11. http://gcc.gnu.org/projects/cxx1y.html
- 12. http://gcc.gnu.org/projects/cxx1y.html
- 13. http://gcc.gnu.org/projects/cxx1y.html
- 14. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3639.html
- 15. http://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html
- 16. https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2011
- 17. https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2014
- 18. https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2014
- 19. https://sourceware.org/gdb/current/onlinedocs/gdb/Xmethods-In-Python.html
- 20. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html
- 21. https://gcc.gnu.org/onlinedocs/gcc/Language-Independent-Options.html
- 22. https://gcc.gnu.org/install/configure.html
- 23. https://gcc.gnu.org/onlinedocs/gfortran/Thread-safety-of-the-runtime-library.html
- 24. https://gcc.gnu.org/wiki/Fortran2003Status
- 25. https://gcc.gnu.org/wiki/Fortran2008Status
- 26. https://gcc.gnu.org/wiki/Coarray
- 27. http://www.opencoarrays.org/
- 28. http://golang.org/cmd/go
- 29. http://golang.org/cmd/gofmt
- 30. https://gcc.gnu.org/onlinedocs/jit/intro/index.html
- 31. https://gcc.gnu.org/onlinedocs/jit/cp/index.html
- 32. https://github.com/davidmalcolm/pygccjit
- 33. https://github.com/ibuclaw/gccjitd
- 34. https://gcc.gnu.org/onlinedocs/jit/intro/tutorial04.html
- 35. https://gcc.gnu.org/onlinedocs/jit/intro/tutorial05.html
- 36. https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf
- 37. https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf
- 38. https://gcc.gnu.org/onlinedocs/
- 39. mailto:gcc-help at gcc.gnu.org
- 40. mailto:gcc at gcc.gnu.org
- 41. https://gcc.gnu.org/lists.html
- 42. http://www.fsf.org/
- 43. https://gcc.gnu.org/about.html
- 44. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.9/index.html
- GCC 4.9 Release Series
-
- October 30, 2014
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.9.2.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.9.1 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.9.2
- October 30, 2014 ([2]changes, [3]documentation)
-
- GCC 4.9.1
- July 16, 2014 ([4]changes, [5]documentation)
-
- GCC 4.9.0
- April 22, 2014 ([6]changes, [7]documentation)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [8]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [9]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [10]GCC
- project web site or contact the [11]GCC development mailing list.
-
- To obtain GCC please use [12]our mirror sites or [13]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [14]GCC manuals. If that fails, the
- [15]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [16]gcc at gcc.gnu.org. All of [17]our lists have public
- archives.
-
- Copyright (C) [18]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [19]maintained by the GCC team. Last modified
- 2014-10-30[20].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.9/changes.html
- 3. http://gcc.gnu.org/onlinedocs/4.9.2/
- 4. http://gcc.gnu.org/gcc-4.9/changes.html
- 5. http://gcc.gnu.org/onlinedocs/4.9.1/
- 6. http://gcc.gnu.org/gcc-4.9/changes.html
- 7. https://gcc.gnu.org/onlinedocs/4.9.0/
- 8. http://gcc.gnu.org/gcc-4.9/buildstat.html
- 9. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 10. http://gcc.gnu.org/index.html
- 11. mailto:gcc at gcc.gnu.org
- 12. http://gcc.gnu.org/mirrors.html
- 13. http://gcc.gnu.org/svn.html
- 14. https://gcc.gnu.org/onlinedocs/
- 15. mailto:gcc-help at gcc.gnu.org
- 16. mailto:gcc at gcc.gnu.org
- 17. https://gcc.gnu.org/lists.html
- 18. http://www.fsf.org/
- 19. https://gcc.gnu.org/about.html
- 20. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.9/changes.html
- GCC 4.9 Release Series
- Changes, New Features, and Fixes
+ This page is a brief summary of some of the huge number of improvements
+ in GCC 6. For more information, see the [1]Porting to GCC 6 page and
+ the [2]full GCC documentation.
Caveats
- * The mudflap run time checker has been removed. The mudflap options
- remain, but do nothing.
+ * The default mode for C++ is now -std=gnu++14 instead of
+ -std=gnu++98.
* Support for a number of older systems and recently unmaintained or
- untested target ports of GCC has been declared obsolete in GCC 4.9.
+ untested target ports of GCC has been declared obsolete in GCC 6.
Unless there is activity to revive them, the next release of GCC
will have their sources permanently removed.
The following ports for individual systems on particular
architectures have been obsoleted:
- + Solaris 9 (*-*-solaris2.9). Details can be found in the
- [1]announcement.
- * On AArch64, the singleton vector types int64x1_t, uint64x1_t and
- float64x1_t exported by arm_neon.h are defined to be the same as
- their base types. This results in incorrect application of
- parameter passing rules to arguments of types int64x1_t and
- uint64x1_t, with respect to the AAPCS64 ABI specification. In
- addition, names of C++ functions with parameters of these types
- (including float64x1_t) are not mangled correctly. The current
- typedef declarations also unintentionally allow implicit casting
- between singleton vector types and their base types. These issues
- will be resolved in a near future release. See [2]PR60825 for more
- information.
-
- More information on porting to GCC 4.9 from previous versions of GCC
- can be found in the [3]porting guide for this release.
+ + SH5 / SH64 (sh64-*-*) as announced [3]here.
General Optimizer Improvements
- * AddressSanitizer, a fast memory error detector, is now available on
- ARM.
- * UndefinedBehaviorSanitizer (ubsan), a fast undefined behavior
- detector, has been added and can be enabled via
- -fsanitize=undefined. Various computations will be instrumented to
- detect undefined behavior at runtime. UndefinedBehaviorSanitizer is
- currently available for the C and C++ languages.
- * Link-time optimization (LTO) improvements:
- + Type merging was rewritten. The new implementation is
- significantly faster and uses less memory.
- + Better partitioning algorithm resulting in less streaming
- during link time.
- + Early removal of virtual methods reduces the size of object
- files and improves link-time memory usage and compile time.
- + Function bodies are now loaded on-demand and released early
- improving overall memory usage at link time.
- + C++ hidden keyed methods can now be optimized out.
- + When using a linker plugin, compiling with the -flto option
- now generates slim object files (.o) which only contain
- intermediate language representation for LTO. Use
- -ffat-lto-objects to create files which contain additionally
- the object code. To generate static libraries suitable for LTO
- processing, use gcc-ar and gcc-ranlib; to list symbols from a
- slim object file use gcc-nm. (This requires that ar, ranlib
- and nm have been compiled with plugin support.)
- Memory usage building Firefox with debug enabled was reduced from
- 15GB to 3.5GB; link time from 1700 seconds to 350 seconds.
+ * UndefinedBehaviorSanitizer gained a new sanitization option,
+ -fsanitize=bounds-strict, which enables strict checking of array
+ bounds. In particular, it enables -fsanitize=bounds as well as
+ instrumentation of flexible array member-like arrays.
+ * Type-based alias analysis now disambiguates accesses to different
+ pointers. This improves precision of the alias oracle by about
+ 20-30% on higher-level C++ programs. Programs doing invalid type
+ punning of pointer types may now need -fno-strict-aliasing to work
+ correctly.
+ * Alias analysis now correctly supports weakref and alias attributes.
+ This makes it possible to access both a variable and its alias in
+ one translation unit which is common with link-time optimization.
+ * Value range propagation now assumes that the this pointer of C++
+ member functions is non-null. This eliminates common null pointer
+ checks but also breaks some non-conforming code-bases (such as
+ Qt-5, Chromium, KDevelop). As a temporary work-around
+ -fno-delete-null-pointer-checks can be used. Wrong code can be
+ identified by using -fsanitize=undefined.
+ * Link-time optimization improvements:
+ + warning and error attributes are now correctly preserved by
+ declaration linking and thus -D_FORTIFY_SOURCE=2 is now
+ supported with -flto.
+ + Type merging was fixed to handle C and Fortran
+ interoperability rules as defined by the Fortran 2008 language
+ standard.
+ As an exception, CHARACTER(KIND=C_CHAR) is not inter-operable
+ with char in all cases because it is an array while char is
+ scalar. INTEGER(KIND=C_SIGNED_CHAR) should be used instead. In
+ general, this inter-operability cannot be implemented, for
+ example, on targets where function passing conventions of
+ arrays differs from scalars.
+ + More type information is now preserved at link time reducing
+ the loss of accuracy of the type based alias analysis compared
+ to builds without link-time optimization.
+ + Invalid type punning on global variables and declarations is
+ now reported with -Wodr-type-mismatch.
+ + The size of LTO object files was reduced by about 11%
+ (measured by compiling Firefox 46.0).
+ + Link-time parallelization (enabled using -flto=n) was
+ significantly improved by decreasing the size of streamed data
+ when partitioning programs. The size of streamed IL while
+ compiling Firefox 46.0 was reduced by 66%.
+ + The linker plugin was extended to pass information about type
+ of binary produced to GCC back end (that can be also manually
+ controlled by -flinker-output). This makes it possible to
+ properly configure the code generator and support incremental
+ linking. Incremental linking of LTO objects by gcc -r is now
+ supported on plugin-enabled setups.
+ There are two ways to perform incremental linking:
+ 1. Linking by ld -r will result in an object file with all
+ sections from individual object files mechanically
+ merged. This delays the actual link time optimization to
+ final linking step and thus permits whole program
+ optimization. Linking final binary with such object files
+ is however slower.
+ 2. Linking by gcc -r will lead to link time optimization and
+ produce final binary into the object file. Linking such
+ object file is fast but avoids any benefits from whole
+ program optimization.
+ GCC 7 will support incremental link-time optimization with gcc
+ -r.
* Inter-procedural optimization improvements:
- + New type inheritance analysis module improving
- devirtualization. Devirtualization now takes into account
- anonymous name-spaces and the C++11 final keyword.
- + New speculative devirtualization pass (controlled by
- -fdevirtualize-speculatively.
- + Calls that were speculatively made direct are turned back to
- indirect where direct call is not cheaper.
- + Local aliases are introduced for symbols that are known to be
- semantically equivalent across shared libraries improving
- dynamic linking times.
- * Feedback directed optimization improvements:
- + Profiling of programs using C++ inline functions is now more
- reliable.
- + New time profiling determines typical order in which functions
- are executed.
- + A new function reordering pass (controlled by
- -freorder-functions) significantly reduces startup time of
- large applications. Until binutils support is completed, it is
- effective only with link-time optimization.
- + Feedback driven indirect call removal and devirtualization now
- handle cross-module calls when link-time optimization is
- enabled.
+ + Basic jump threading is now performed before profile
+ construction and inline analysis, resulting in more realistic
+ size and time estimates that drive the heuristics of the of
+ inliner and function cloning passes.
+ + Function cloning now more aggressively eliminates unused
+ function parameters.
New Languages and Language specific improvements
- * Version 4.0 of the [4]OpenMP specification is now supported in the
- C and C++ compilers and starting with the 4.9.1 release also in the
- Fortran compiler. The new -fopenmp-simd option can be used to
- enable OpenMP's SIMD directives, while ignoring other OpenMP
- directives. The new [5]-fsimd-cost-model= option permits to tune
- the vectorization cost model for loops annotated with OpenMP and
- Cilk Plus simd directives; -Wopenmp-simd warns when the current
- cost model overrides simd directives set by the user.
- * The -Wdate-time option has been added for the C, C++ and Fortran
- compilers, which warns when the __DATE__, __TIME__ or __TIMESTAMP__
- macros are used. Those macros might prevent bit-wise-identical
- reproducible compilations.
-
- Ada
-
- * GNAT switched to Ada 2012 instead of Ada 2005 by default.
+ Compared to GCC 5, the GCC 6 release series includes a much improved
+ implementation of the [4]OpenACC 2.0a specification. Highlights are:
+ * In addition to single-threaded host-fallback execution, offloading
+ is supported for nvptx (Nvidia GPUs) on x86_64 and PowerPC 64-bit
+ little-endian GNU/Linux host systems. For nvptx offloading, with
+ the OpenACC parallel construct, the execution model allows for an
+ arbitrary number of gangs, up to 32 workers, and 32 vectors.
+ * Initial support for parallelized execution of OpenACC kernels
+ constructs:
+ + Parallelization of a kernels region is switched on by
+ -fopenacc combined with -O2 or higher.
+ + Code is offloaded onto multiple gangs, but executes with just
+ one worker, and a vector length of 1.
+ + Directives inside a kernels region are not supported.
+ + Loops with reductions can be parallelized.
+ + Only kernels regions with one loop nest are parallelized.
+ + Only the outer-most loop of a loop nest can be parallelized.
+ + Loop nests containing sibling loops are not parallelized.
+ Typically, using the OpenACC parallel construct gives much better
+ performance, compared to the initial support of the OpenACC kernels
+ construct.
+ * The device_type clause is not supported. The bind and nohost
+ clauses are not supported. The host_data directive is not supported
+ in Fortran.
+ * Nested parallelism (cf. CUDA dynamic parallelism) is not supported.
+ * Usage of OpenACC constructs inside multithreaded contexts (such as
+ created by OpenMP, or pthread programming) is not supported.
+ * If a call to the acc_on_device function has a compile-time constant
+ argument, the function call evaluates to a compile-time constant
+ value only for C and C++ but not for Fortran.
+
+ See the [5]OpenACC and [6]Offloading wiki pages for further
+ information.
C family
- * Support for colorizing diagnostics emitted by GCC has been added.
- The [6]-fdiagnostics-color=auto will enable it when outputting to
- terminals, -fdiagnostics-color=always unconditionally. The
- GCC_COLORS environment variable can be used to customize the colors
- or disable coloring. If GCC_COLORS variable is present in the
- environment, the default is -fdiagnostics-color=auto, otherwise
- -fdiagnostics-color=never.
- Sample diagnostics output:
- $ g++ -fdiagnostics-color=always -S -Wall test.C
- test.C: In function ‘int foo()’:
- test.C:1:14: warning: no return statement in function returning non-void [-W
-return-type]
- int foo () { }
- ^
- test.C:2:46: error: template instantiation depth exceeds maximum of 900 (use
- -ftemplate-depth= to increase the maximum) instantiating ‘struct X<100>’
- template <int N> struct X { static const int value = X<N-1>::value; }; temp
-late struct X<1000>;
- ^
- test.C:2:46: recursively required from ‘const int X<999>::value’
- test.C:2:46: required from ‘const int X<1000>::value’
- test.C:2:88: required from here
+ * Version 4.5 of the [7]OpenMP specification is now supported in the
+ C and C++ compilers.
+ * The C and C++ compilers now support attributes on enumerators. For
+ instance, it is now possible to mark enumerators as deprecated:
+
+enum {
+ newval,
+ oldval __attribute__ ((deprecated ("too old")))
+};
- test.C:2:46: error: incomplete type ‘X<100>’ used in nested name specifier
+ * Source locations for the C and C++ compilers are now tracked as
+ ranges, rather than just points, making it easier to identify the
+ subexpression of interest within a complicated expression. For
+ example:
- * With the new [7]#pragma GCC ivdep, the user can assert that there
- are no loop-carried dependencies which would prevent concurrent
- execution of consecutive iterations using SIMD (single instruction
- multiple data) instructions.
- * Support for [8]Cilk Plus has been added and can be enabled with the
- -fcilkplus option. Cilk Plus is an extension to the C and C++
- languages to support data and task parallelism. The present
- implementation follows ABI version 1.2; all features but _Cilk_for
- have been implemented.
+test.cc: In function 'int test(int, int, foo, int, int)':
+test.cc:5:16: error: no match for 'operator*' (operand types are 'int' and 'foo'
+)
+ return p + q * r * s + t;
+ ~~^~~
+
+ In addition, there is now initial support for precise diagnostic
+ locations within strings:
+
+format-strings.c:3:14: warning: field width specifier '*' expects a matching 'in
+t' argument [-Wformat=]
+ printf("%*d");
+ ^
+
+ * Diagnostics can now contain "fix-it hints", which are displayed in
+ context underneath the relevant source code. For example:
+
+fixits.c: In function 'bad_deref':
+fixits.c:11:13: error: 'ptr' is a pointer; did you mean to use '->'?
+ return ptr.x;
+ ^
+ ->
+
+ * The C and C++ compilers now offer suggestions for misspelled field
+ names:
+
+spellcheck-fields.cc:52:13: error: 'struct s' has no member named 'colour'; did
+you mean 'color'?
+ return ptr->colour;
+ ^~~~~~
+
+ * New command-line options have been added for the C and C++
+ compilers:
+ + -Wshift-negative-value warns about left shifting a negative
+ value.
+ + -Wshift-overflow warns about left shift overflows. This
+ warning is enabled by default. -Wshift-overflow=2 also warns
+ about left-shifting 1 into the sign bit.
+ + -Wtautological-compare warns if a self-comparison always
+ evaluates to true or false. This warning is enabled by -Wall.
+ + -Wnull-dereference warns if the compiler detects paths that
+ trigger erroneous or undefined behavior due to dereferencing a
+ null pointer. This option is only active when
+ -fdelete-null-pointer-checks is active, which is enabled by
+ optimizations in most targets. The precision of the warnings
+ depends on the optimization options used.
+ + -Wduplicated-cond warns about duplicated conditions in an
+ if-else-if chain.
+ + -Wmisleading-indentation warns about places where the
+ indentation of the code gives a misleading idea of the block
+ structure of the code to a human reader. For example, given
+ [8]CVE-2014-1266:
+
+sslKeyExchange.c: In function 'SSLVerifySignedServerKeyExchange':
+sslKeyExchange.c:629:3: warning: this 'if' clause does not guard... [-Wmisleadin
+g-indentation]
+ if ((err = SSLHashSHA1.update(&hashCtx, &signedParams)) != 0)
+ ^~
+sslKeyExchange.c:631:5: note: ...this statement, but the latter is misleadingly
+indented as if it is guarded by the 'if'
+ goto fail;
+ ^~~~
+
+ This warning is enabled by -Wall.
+ * The C and C++ compilers now emit saner error messages if
+ merge-conflict markers are present in a source file.
+
+test.c:3:1: error: version control conflict marker in file
+ <<<<<<< HEAD
+ ^~~~~~~
C
- * ISO C11 atomics (the _Atomic type specifier and qualifier and the
- <stdatomic.h> header) are now supported.
- * ISO C11 generic selections (_Generic keyword) are now supported.
- * ISO C11 thread-local storage (_Thread_local, similar to GNU C
- __thread) is now supported.
- * ISO C11 support is now at a similar level of completeness to ISO
- C99 support: substantially complete modulo bugs, extended
- identifiers (supported except for corner cases when
- -fextended-identifiers is used), floating-point issues (mainly but
- not entirely relating to optional C99 features from Annexes F and
- G) and the optional Annexes K (Bounds-checking interfaces) and L
- (Analyzability).
- * A new C extension __auto_type provides a subset of the
- functionality of C++11 auto in GNU C.
+ * It is possible to disable warnings when an initialized field of a
+ structure or a union with side effects is being overridden when
+ using designated initializers via a new warning option
+ -Woverride-init-side-effects.
+ * A new type attribute scalar_storage_order applying to structures
+ and unions has been introduced. It specifies the storage order (aka
+ endianness) in memory of scalar fields in structures or unions.
C++
- * The G++ implementation of [9]C++1y return type deduction for normal
- functions has been updated to conform to [10]N3638, the proposal
- accepted into the working paper. Most notably, it adds
- decltype(auto) for getting decltype semantics rather than the
- template argument deduction semantics of plain auto:
-
-int& f();
- auto i1 = f(); // int
-decltype(auto) i2 = f(); // int&
-
- * G++ supports [11]C++1y lambda capture initializers:
-
-[x = 42]{ ... };
-
- Actually, they have been accepted since GCC 4.5, but now the
- compiler doesn't warn about them with -std=c++1y, and supports
- parenthesized and brace-enclosed initializers as well.
- * G++ supports [12]C++1y variable length arrays. G++ has supported
- GNU/C99-style VLAs for a long time, but now additionally supports
- initializers and lambda capture by reference. In C++1y mode G++
- will complain about VLA uses that are not permitted by the draft
- standard, such as forming a pointer to VLA type or applying sizeof
- to a VLA variable. Note that it now appears that VLAs will not be
- part of C++14, but will be part of a separate document and then
- perhaps C++17.
-
-void f(int n) {
- int a[n] = { 1, 2, 3 }; // throws std::bad_array_length if n < 3
- [&a]{ for (int i : a) { cout << i << endl; } }();
- &a; // error, taking address of VLA
-}
-
- * G++ supports the [13]C++1y [[deprecated]] attribute modulo bugs in
- the underlying [[gnu::deprecated]] attribute. Classes and functions
- can be marked deprecated and a diagnostic message added:
-
-class A;
-int bar(int n);
-#if __cplusplus > 201103
-class [[deprecated("A is deprecated in C++14; Use B instead")]] A;
-[[deprecated("bar is unsafe; use foo() instead")]]
-int bar(int n);
-
-int foo(int n);
-class B;
-#endif
-A aa; // warning: 'A' is deprecated : A is deprecated in C++14; Use B instead
-int j = bar(2); // warning: 'int bar(int)' is deprecated : bar is unsafe; use fo
-o() instead
-
- * G++ supports [14]C++1y digit separators. Long numeric literals can
- be subdivided with a single quote ' to enhance readability:
-
-int i = 1048576;
-int j = 1'048'576;
-int k = 0x10'0000;
-int m = 0'004'000'000;
-int n = 0b0001'0000'0000'0000'0000'0000;
-
-double x = 1.602'176'565e-19;
-double y = 1.602'176'565e-1'9;
-
- * G++ supports [15]C++1y generic (polymorphic) lambdas.
-
-// a functional object that will increment any type
-auto incr = [](auto x) { return x++; };
-
- * As a GNU extension, G++ supports explicit template parameter syntax
- for generic lambdas. This can be combined in the expected way with
- the standard auto syntax.
-
-// a functional object that will add two like-type objects
-auto add = [] <typename T> (T a, T b) { return a + b; };
-
- * G++ supports unconstrained generic functions as specified by §4.1.2
- and §5.1.1 of [16]N3889: Concepts Lite Specification. Briefly, auto
- may be used as a type-specifier in a parameter declaration of any
- function declarator in order to introduce an implicit function
- template parameter, akin to generic lambdas.
-
-// the following two function declarations are equivalent
-auto incr(auto x) { return x++; }
-template <typename T>
-auto incr(T x) { return x++; }
+ * The default mode has been changed to -std=gnu++14.
+ * [9]C++ Concepts are now supported when compiling with -fconcepts.
+ * -flifetime-dse is more aggressive in dead-store elimination in
+ situations where a memory store to a location precedes a
+ constructor to the memory location.
+ * G++ now supports [10]C++17 fold expressions, u8 character literals,
+ extended static_assert, and nested namespace definitions.
+ * G++ now allows constant evaluation for all non-type template
+ arguments.
+ * G++ now supports C++ Transactional Memory when compiling with
+ -fgnu-tm.
Runtime Library (libstdc++)
- * [17]Improved support for C++11, including:
- + support for <regex>;
- + The associative containers in <map> and <set> and the
- unordered associative containers in <unordered_map> and
- <unordered_set> meet the allocator-aware container
- requirements;
- * [18]Improved experimental support for the upcoming ISO C++
- standard, C++14, including:
- + fixing constexpr member functions without const;
- + implementation of the std::exchange() utility function;
- + addressing tuples by type;
- + implemention of std::make_unique;
- + implemention of std::shared_lock;
- + making std::result_of SFINAE-friendly;
- + adding operator() to std::integral_constant;
- + adding user-defined literals for standard library types
- std::basic_string, std::chrono::duration, and std::complex;
- + adding two range overloads to non-modifying sequence oprations
- std::equal and std::mismatch;
- + adding IO manipulators for quoted strings;
- + adding constexpr members to <utility>, <complex>, <chrono>,
- and some containers;
- + adding compile-time std::integer_sequence;
- + adding cleaner transformation traits;
- + making <functional>s operator functors easier to use and more
- generic;
- * An implementation of std::experimental::optional.
- * An implementation of std::experimental::string_view.
- * The non-standard function std::copy_exception has been deprecated
- and will be removed in a future version. std::make_exception_ptr
- should be used instead.
+ * Extensions to the C++ Library to support mathematical special
+ functions (ISO/IEC 29124:2010), thanks to Edward Smith-Rowland.
+ * Experimental support for C++17, including the following new
+ features:
+ + std::uncaught_exceptions function (this is also available for
+ -std=gnu++NN modes);
+ + new member functions try_emplace and insert_or_assign for
+ unique_key maps;
+ + non-member functions std::size, std::empty, and std::data for
+ accessing containers and arrays;
+ + std::invoke;
+ + std::shared_mutex;
+ + std::void_t and std::bool_constant metaprogramming utilities.
+ Thanks to Ville Voutilainen for contributing many of the C++17
+ features.
+ * An experimental implementation of the File System TS.
+ * Experimental support for most features of the second version of the
+ Library Fundamentals TS. This includes polymorphic memory resources
+ and array support in shared_ptr, thanks to Fan You.
+ * Some assertions checked by Debug Mode can now also be enabled by
+ _GLIBCXX_ASSERTIONS. The subset of checks enabled by the new macro
+ have less run-time overhead than the full _GLIBCXX_DEBUG checks and
+ don't affect the library ABI, so can be enabled per-translation
+ unit.
+ * Timed mutex types are supported on more targets, including Darwin.
+ * Improved std::locale support for DragonFly and FreeBSD, thanks to
+ John Marino and Andreas Tobler.
Fortran
- * Compatibility notice:
- + Module files: The version of the module files (.mod) has been
- incremented; additionally, module files are now compressed.
- Fortran MODULEs compiled by earlier GCC versions have to be
- recompiled, when they are USEd by files compiled with GCC 4.9.
- GCC 4.9 is not able to read .mod files of earlier GCC
- versions; attempting to do so gives an error message. Note:
- The ABI of the produced assembler data itself has not changed:
- object files and libraries are fully compatible with older
- versions (except as stated below).
- + ABI changes:
- o The [19]argument passing ABI has changed for scalar dummy
- arguments of type INTEGER, REAL, COMPLEX and LOGICAL,
- which have both the VALUE and the OPTIONAL attributes.
- o To support finalization the virtual table associated with
- polymorphic variables has changed. Code containing CLASS
- should be recompiled, including all files which define
- derived types involved in the type definition used by
- polymorphic variables. (Note: Due to the incremented
- module version, trying to mix old code with new code will
- usually give an error message.)
- + GNU Fortran no longer deallocates allocatable variables or
- allocatable components of variables declared in the main
- program. Since Fortran 2008, the standard explicitly states
- that variables declared in the Fortran main program
- automatically have the SAVE attribute.
- + When opening files, the close-on-exec flag is set if the
- system supports such a feature. This is generally considered
- good practice these days, but if there is a need to pass file
- descriptors to child processes the parent process must now
- remember to clear the close-on-exec flag by calling fcntl(),
- e.g. via ISO_C_BINDING, before executing the child process.
- * The deprecated command-line option -fno-whole-file has been
- removed. (-fwhole-file is the default since GCC 4.6.)
- -fwhole-file/-fno-whole-file continue to be accepted but do not
- influence the code generation.
- * The compiler no longer unconditionally warns about DO loops with
- zero iterations. This warning is now controlled by the -Wzerotrip
- option, which is implied by -Wall.
- * The new NO_ARG_CHECK attribute of the [20]!GCC$ directive can be
- used to disable the type-kind-rank (TKR) argument check for a dummy
- argument. The feature is similar to ISO/IEC TS 29133:2012's
- TYPE(*), except that it additionally also disables the rank check.
- Variables with NO_ARG_CHECK have to be dummy arguments and may only
- be used as argument to ISO_C_BINDING's C_LOC and as actual argument
- to another NO_ARG_CHECK dummy argument; also the other constraints
- of TYPE(*) apply. The dummy arguments should be declared as scalar
- or assumed-size variable of type type(*) (recommended) – or of type
- integer, real, complex or logical. With NO_ARG_CHECK, a pointer to
- the data without further type or shape information is passed,
- similar to C's void*. Note that also TS 29113's
- type(*),dimension(..) accepts arguments of any type and rank;
- contrary to NO_ARG_CHECK assumed-rank arguments pass an array
- descriptor which contains the array shape and stride of the
- argument.
- * [21]Fortran 2003:
- + Finalization is now supported. It is currently only done for a
- subset of those situations in which it should occur.
- + Experimental support for scalar character components with
- deferred length (i.e. allocatable string length) in derived
- types has been added. (Deferred-length character variables are
- supported since GCC 4.6.)
- * [22]Fortran 2008:
- + When STOP or ERROR STOP are used to terminate the execution
- and any exception (but inexact) is signaling, a warning is
- printed to ERROR_UNIT, indicating which exceptions are
- signaling. The [23]-ffpe-summary= command-line option can be
- used to fine-tune for which exceptions the warning should be
- shown.
- + Rounding on input (READ) is now handled on systems where
- strtod honours the rounding mode. (For output, rounding is
- supported since GCC 4.5.) Note that for input, the compatible
- rounding mode is handled as nearest (i.e., for a tie, rounding
- to an even last significant [cf. IEC 60559:1989] – while
- compatible rounds away from zero for a tie).
+ * The MATMUL intrinsic is now inlined for straightforward cases if
+ front-end optimization is active. The maximum size for inlining can
+ be set to n with the -finline-matmul-limit=n option and turned off
+ with -finline-matmul-llimit=0.
+ * The -Wconversion-extra option will warn about REAL constants which
+ have excess precision for their kind.
+ * The -Winteger-division option has been added, which warns about
+ divisions of integer constants which are truncated. This option is
+ included in -Wall by default.
- Go
+libgccjit
- * GCC 4.9 provides a complete implementation of the Go 1.2.1 release.
+ * The driver code is now run in-process within libgccjit, providing a
+ small speed-up of the compilation process.
+ * The API has gained entrypoints for
+ + [11]timing how long was spent in different parts of code,
+ + [12]creating switch statements,
+ + [13]allowing unreachable basic blocks in a function, and
+ + [14]adding arbitrary command-line options to a compilation.
New Targets and Target Specific Improvements
AArch64
- * The ARMv8-A crypto and CRC instructions are now supported through
- intrinsics. These are enabled when the architecture supports these
- and are available through the -march=armv8-a+crc and
- -march=armv8-a+crypto options.
- * Initial support for ILP32 has now been added to the compiler. This
- is now available through the command-line option -mabi=ilp32.
- Support for ILP32 is considered experimental as the ABI
- specification is still beta.
- * Coverage of more of the ISA including the SIMD extensions has been
- added. The Advanced SIMD intrinsics have also been improved.
- * The new local register allocator (LRA) is now on by default for the
- AArch64 backend.
- * The REE (Redundant extension elimination) pass has now been enabled
- by default for the AArch64 backend.
- * Tuning for the Cortex-A53 and Cortex-A57 has been improved.
- * Initial big.LITTLE tuning support for the combination of Cortex-A57
- and Cortex-A53 was added through the -mcpu=cortex-a57.cortex-a53
- option.
- * A number of structural changes have been made to both the ARM and
- AArch64 backends to facilitate improved code-generation.
- * As of GCC 4.9.2 a workaround for the ARM Cortex-A53 erratum 835769
- has been added and can be enabled by giving the
- -mfix-cortex-a53-835769 option. Alternatively it can be enabled by
- default by configuring GCC with the --enable-fix-cortex-a53-835769
- option.
-
- ARC
-
- * A port for Synopsys Designware ARC has been contributed by Embecosm
- and Synopsys Inc.
+ * The new command line options -march=native, -mcpu=native and
+ -mtune=native are now available on native AArch64 GNU/Linux
+ systems. Specifying these options will cause GCC to auto-detect the
+ host CPU and rewrite these options to the optimal setting for that
+ system. If GCC is unable to detect the host CPU these options have
+ no effect.
+ * -fpic is now supported by the AArch64 target when generating code
+ for the small code model (-mcmodel=small). The size of the global
+ offset table (GOT) is limited to 28KiB under the LP64 SysV ABI ,
+ and 15KiB under the ILP32 SysV ABI.
+ * The AArch64 port now supports target attributes and pragmas. Please
+ refer to the [15]documentation for details of available attributes
+ and pragmas as well as usage instructions.
+ * Link-time optimization across translation units with different
+ target-specific options is now supported.
ARM
- * Use of Advanced SIMD (Neon) for 64-bit scalar computations has been
- disabled by default. This was found to generate better code in only
- a small number of cases. It can be turned back on with the
- -mneon-for-64bits option.
- * Further support for the ARMv8-A architecture, notably implementing
- the restriction around IT blocks in the Thumb32 instruction set has
- been added. The -mrestrict-it option can be used with
- -march=armv7-a or the -march=armv7ve options to make code
- generation fully compatible with the deprecated instructions in
- ARMv8-A.
- * Support has now been added for the ARMv7ve variant of the
- architecture. This can be used by the -march=armv7ve option.
- * The ARMv8-A crypto and CRC instructions are now supported through
- intrinsics and are available through the -march=armv8-a+crc and
- mfpu=crypto-neon-fp-armv8 options.
- * LRA is now on by default for the ARM target. This can be turned off
- using the -mno-lra option. This option is a purely transitionary
- command-line option and will be removed in a future release. We are
- interested in any bug reports regarding functional and performance
- regressions with LRA.
- * A new option -mslow-flash-data to improve performance of programs
- fetching data on slow flash memory has now been introduced for the
- ARMv7-M profile cores.
- * A new option -mpic-data-is-text-relative for targets that allows
- data segments to be relative to text segments has been added. This
- is on by default for all targets except VxWorks RTP.
- * A number of infrastructural changes have been made to both the ARM
- and AArch64 backends to facilitate improved code-generation.
- * GCC now supports Cortex-A12 and the Cortex-R7 through the
- -mcpu=cortex-a12 and -mcpu=cortex-r7 options.
- * GCC now has tuning for the Cortex-A57 and Cortex-A53 through the
- -mcpu=cortex-a57 and -mcpu=cortex-a53 options.
- * Initial big.LITTLE tuning support for the combination of Cortex-A57
- and Cortex-A53 was added through the -mcpu=cortex-a57.cortex-a53
- option. Similar support was added for the combination of Cortex-A15
- and Cortex-A7 through the -mcpu=cortex-a15.cortex-a7 option.
- * Further performance optimizations for the Cortex-A15 and the
- Cortex-M4 have been added.
- * A number of code generation improvements for Thumb2 to reduce code
- size when compiling for the M-profile processors.
+ * Support for revisions of the ARM architecture prior to ARMv4t has
+ been deprecated and will be removed in a future GCC release. The
+ -mcpu and -mtune values that are deprecated are: arm2, arm250,
+ arm3, arm6, arm60, arm600, arm610, arm620, arm7, arm7d, arm7di,
+ arm70, arm700, arm700i, arm710, arm720, arm710c, arm7100, arm7500,
+ arm7500fe, arm7m, arm7dm, arm7dmi, arm8, arm810, strongarm,
+ strongarm110, strongarm1100, strongarm1110, fa526, fa626. The value
+ arm7tdmi is still supported. The values of -march that are
+ deprecated are: armv2,armv2a,armv3,armv3m,armv4.
+ * The ARM port now supports target attributes and pragmas. Please
+ refer to the [16]documentation for details of available attributes
+ and pragmas as well as usage instructions.
+ * Support has been added for the following processors (GCC
+ identifiers in parentheses): ARM Cortex-A32 (cortex-a32), ARM
+ Cortex-A35 (cortex-a35). The GCC identifiers can be used as
+ arguments to the -mcpu or -mtune options, for example:
+ -mcpu=cortex-a32 or -mtune=cortex-a35.
+
+ Heterogeneous Systems Architecture
+
+ * GCC can now generate HSAIL (Heterogeneous System Architecture
+ Intermediate Language) for simple OpenMP device constructs if
+ configured with --enable-offload-targets=hsa. A new libgomp plugin
+ then runs the HSA GPU kernels implementing these constructs on HSA
+ capable GPUs via a standard HSA run time.
+ If the HSA compilation back end determines it cannot output HSAIL
+ for a particular input, it gives a warning by default. These
+ warnings can be suppressed with -Wno-hsa. To give a few examples,
+ the HSA back end does not implement compilation of code using
+ function pointers, automatic allocation of variable sized arrays,
+ functions with variadic arguments as well as a number of other less
+ common programming constructs.
+ When compilation for HSA is enabled, the compiler attempts to
+ compile composite OpenMP constructs
+
+#pragma omp target teams distribute parallel for
+
+ into parallel HSA GPU kernels.
IA-32/x86-64
- * -mfpmath=sse is now implied by -ffast-math on all targets where
- SSE2 is supported.
- * Intel AVX-512 support was added to GCC. That includes inline
- assembly support, new registers and extending existing ones, new
- intrinsics (covered by corresponding testsuite), and basic
- autovectorization. AVX-512 instructions are available via the
- following GCC switches: AVX-512 foundation instructions: -mavx512f,
- AVX-512 prefetch instructions: -mavx512pf, AVX-512 exponential and
- reciprocal instructions: -mavx512er, AVX-512 conflict detection
- instructions: -mavx512cd.
- * It is now possible to call x86 intrinsics from select functions in
- a file that are tagged with the corresponding target attribute
- without having to compile the entire file with the -mxxx option.
- This improves the usability of x86 intrinsics and is particularly
- useful when doing [24]Function Multiversioning.
- * GCC now supports the new Intel microarchitecture named Silvermont
- through -march=silvermont.
- * GCC now supports the new Intel microarchitecture named Broadwell
- through -march=broadwell.
- * Optimizing for other Intel microarchitectures have been renamed to
- -march=nehalem, westmere, sandybridge, ivybridge, haswell, bonnell.
- * -march=generic has been retuned for better support of Intel core
- and AMD Bulldozer architectures. Performance of AMD K7, K8, Intel
- Pentium-M, and Pentium4 based CPUs is no longer considered
- important for generic.
- * -mtune=intel can now be used to generate code running well on the
- most current Intel processors, which are Haswell and Silvermont for
- GCC 4.9.
- * Support to encode 32-bit assembly instructions in 16-bit format is
- now available through the -m16 command-line option.
- * Better inlining of memcpy and memset that is aware of value ranges
- and produces shorter alignment prologues.
- * -mno-accumulate-outgoing-args is now honored when unwind
- information is output. Argument accumulation is also now turned off
- for portions of programs optimized for size.
- * Support for new AMD family 15h processors (Excavator core) is now
- available through the -march=bdver4 and -mtune=bdver4 options.
-
- MSP430
-
- * A new command-line option -mcpu= has been added to the MSP430
- backend. This option is used to specify the ISA to be used.
- Accepted values are msp430 (the default), msp430x and msp430xv2.
- The ISA is no longer deduced from the -mmcu= option as there are
- far too many different MCU names. The -mmcu= option is still
- supported, and this is still used to select linker scripts and
- generate a C preprocessor symbol that will be recognised by the
- msp430.h header file.
+ * GCC now supports the Intel CPU named Skylake with AVX-512
+ extensions through -march=skylake-avx512. The switch enables the
+ following ISA extensions: AVX-512F, AVX512VL, AVX-512CD, AVX-512BW,
+ AVX-512DQ.
+ * Support for new AMD instructions monitorx and mwaitx has been
+ added. This includes new intrinsic and built-in support. It is
+ enabled through option -mmwaitx. The instructions monitorx and
+ mwaitx implement the same functionality as the old monitor and
+ mwait instructions. In addition mwaitx adds a configurable timer.
+ The timer value is received as third argument and stored in
+ register %ebx.
+ * x86-64 targets now allow stack realignment from a word-aligned
+ stack pointer using the command-line option -mstackrealign or
+ __attribute__ ((force_align_arg_pointer)). This allows functions
+ compiled with a vector-aligned stack to be invoked from objects
+ that keep only word-alignment.
+ * Support for address spaces __seg_fs, __seg_gs, and __seg_tls. These
+ can be used to access data via the %fs and %gs segments without
+ having to resort to inline assembly. Please refer to the
+ [17]documentation for usage instructions.
+ * Support for AMD Zen (family 17h) processors is now available
+ through the -march=znver1 and -mtune=znver1 options.
- NDS32
+ MeP
- * A new nds32 port supports the 32-bit architecture from Andes
- Technology Corporation.
- * The port provides initial support for the V2, V3, V3m instruction
- set architectures.
+ * Support for the MeP (mep-elf) architecture has been deprecated and
+ will be removed in a future GCC release.
- Nios II
+ MSP430
- * A port for the Altera Nios II has been contributed by Mentor
- Graphics.
+ * The MSP430 compiler now has the ability to automatically distribute
+ code and data between low memory (addresses below 64K) and high
+ memory. This only applies to parts that actually have both memory
+ regions and only if the linker script for the part has been
+ specifically set up to support this feature.
+ A new attribute of either can be applied to both functions and
+ data, and this tells the compiler to place the object into low
+ memory if there is room and into high memory otherwise. Two other
+ new attributes - lower and upper - can be used to explicitly state
+ that an object should be placed in the specified memory region. If
+ there is not enough left in that region the compilation will fail.
+ Two new command-line options - -mcode-region=[lower|upper|either]
+ and -mdata-region=[lower|upper|either] - can be used to tell the
+ compiler what to do with objects that do not have one of these new
+ attributes.
PowerPC / PowerPC64 / RS6000
- * GCC now supports Power ISA 2.07, which includes support for
- Hardware Transactional Memory (HTM), Quadword atomics and several
- VMX and VSX additions, including Crypto, 64-bit integer, 128-bit
- integer and decimal integer operations.
- * Support for the POWER8 processor is now available through the
- -mcpu=power8 and -mtune=power8 options.
- * The libitm library has been modified to add a HTM fastpath that
- automatically uses POWER's HTM hardware instructions when it is
- executing on a HTM enabled processor.
- * Support for the new powerpc64le-linux platform has been added. It
- defaults to generating code that conforms to the ELFV2 ABI.
-
- S/390, System z
-
- * Support for the Transactional Execution Facility included with the
- IBM zEnterprise zEC12 processor has been added. A set of GCC style
- builtins as well as XLC style builtins are provided. The builtins
- are enabled by default when using the -march=zEC12 option but can
- explicitly be disabled with -mno-htm. Using the GCC builtins also
- libitm supports hardware transactions on S/390.
- * The hotpatch features allows to prepare functions for hotpatching.
- A certain amount of bytes is reserved before the function entry
- label plus a NOP is inserted at its very beginning to implement a
- backward jump when applying a patch. The feature can either be
- enabled per compilation unit via the command-line option -mhotpatch
- or per function using the hotpatch attribute.
- * The shrink wrap optimization is now supported on S/390 and enabled
- by default.
- * A major rework of the routines to determine which registers need to
- be saved and restored in function prologue/epilogue now allow to
- use floating point registers as save slots. This will happen for
- certain leaf function with -march=z10 or higher.
- * The LRA rtl pass replaces reload by default on S/390.
-
- RX
-
- * The port now allows to specify the RX100, RX200, and RX600
- processors with the command-line options -mcpu=rx100, -mcpu=rx200
- and -mcpu=rx600.
+ * PowerPC64 now supports IEEE 128-bit floating-point using the
+ __float128 data type. In GCC 6, this is NOT enabled by default, but
+ you can enable it with -mfloat128. The IEEE 128-bit floating-point
+ support requires the use of the VSX instruction set. IEEE 128-bit
+ floating-point values are passed and returned as a single vector
+ value. The software emulator for IEEE 128-bit floating-point
+ support is only built on PowerPC Linux systems where the default
+ cpu is at least power7. On future ISA 3.0 systems (power9 and
+ later), you will be able to use the -mfloat128-hardware option to
+ use the ISA 3.0 instructions that support IEEE 128-bit
+ floating-point. An additional type (__ibm128) has been added to
+ refer to the IBM extended double type that normally implements long
+ double. This will allow for a future transition to implementing
+ long double with IEEE 128-bit floating-point.
+ * Basic support has been added for POWER9 hardware that will use the
+ recently published OpenPOWER ISA 3.0 instructions. The following
+ new switches are available:
+ + -mcpu=power9: Implement all of the ISA 3.0 instructions
+ supported by the compiler.
+ + -mtune=power9: In the future, apply tuning for POWER9 systems.
+ Currently, POWER8 tunings are used.
+ + -mmodulo: Generate code using the ISA 3.0 integer instructions
+ (modulus, count trailing zeros, array index support, integer
+ multiply/add).
+ + -mpower9-fusion: Generate code to suitably fuse instruction
+ sequences for a POWER9 system.
+ + -mpower9-dform: Generate code to use the new D-form (register
+ +offset) memory instructions for the vector registers.
+ + -mpower9-vector: Generate code using the new ISA 3.0 vector
+ (VSX or Altivec) instructions.
+ + -mpower9-minmax: Reserved for future development.
+ + -mtoc-fusion: Keep TOC entries together to provide more fusion
+ opportunities.
+ * New constraints have been added to support IEEE 128-bit
+ floating-point and ISA 3.0 instructions:
+ + wb: Altivec register if -mpower9-dform is enabled.
+ + we: VSX register if -mpower9-vector is enabled for 64-bit code
+ generation.
+ + wo: VSX register if -mpower9-vector is enabled.
+ + wp: Reserved for future use if long double is implemented with
+ IEEE 128-bit floating-point instead of IBM extended double.
+ + wq: VSX register if -mfloat128 is enabled.
+ + wF: Memory operand suitable for POWER9 fusion load/store.
+ + wG: Memory operand suitable for TOC fusion memory references.
+ + wL: Integer constant identifying the element number mfvsrld
+ accesses within a vector.
+ * Support has been added for __builtin_cpu_is () and
+ __builtin_cpu_supports (), allowing for very fast access to
+ AT_PLATFORM, AT_HWCAP, and AT_HWCAP2 values. This requires use of
+ glibc 2.23 or later.
+ * All hardware transactional memory builtins now correctly behave as
+ memory barriers. Programmers can use #ifdef __TM_FENCE__ to
+ determine whether their "old" compiler treats the builtins as
+ barriers.
+ * Split-stack support has been added for gccgo on PowerPC64 for both
+ big- and little-endian (but NOT for 32-bit). The gold linker from
+ at least binutils 2.25.1 must be available in the PATH when
+ configuring and building gccgo to enable split stack. (The
+ requirement for binutils 2.25.1 applies to PowerPC64 only.) The
+ split-stack feature allows a small initial stack size to be
+ allocated for each goroutine, which increases as needed.
+ * GCC on PowerPC now supports the standard lround function.
+ * A new configuration option ---with-advance-toolchain=at was added
+ for PowerPC 64-bit GNU/Linux systems to use the header files,
+ library files, and the dynamic linker from a specific Advance
+ Toolchain release instead of the default versions that are provided
+ by the GNU/Linux distribution. In general, this option is intended
+ for the developers of GCC, and it is not intended for general use.
+ * The "q", "S", "T", and "t" asm-constraints have been removed.
+ * The "b", "B", "m", "M", and "W" format modifiers have been removed.
+
+ S/390, System z, IBM z Systems
+
+ * Support for the IBM z13 processor has been added. When using the
+ -march=z13 option, the compiler will generate code making use of
+ the new instructions and registers introduced with the vector
+ extension facility. The -mtune=z13 option enables z13 specific
+ instruction scheduling without making use of new instructions.
+ Compiling code with -march=z13 reduces the default alignment of
+ vector types bigger than 8 bytes to 8. This is an ABI change and
+ care must be taken when linking modules compiled with different
+ arch levels which interchange variables containing vector type
+ values. For newly compiled code the GNU linker will emit a warning.
+ * The -mzvector option enables a C/C++ language extension. This
+ extension provides a new keyword vector which can be used to define
+ vector type variables. (Note: This is not available when enforcing
+ strict standard compliance e.g. with -std=c99. Either enable GNU
+ extensions with e.g. -std=gnu99 or use __vector instead of vector.)
+ Additionally a set of overloaded builtins is provided which is
+ partially compatible to the PowerPC Altivec builtins. In order to
+ make use of these builtins the vecintrin.h header file needs to be
+ included.
+ * The new command line options -march=native, and -mtune=native are
+ now available on native IBM z Systems. Specifying these options
+ will cause GCC to auto-detect the host CPU and rewrite these
+ options to the optimal setting for that system. If GCC is unable to
+ detect the host CPU these options have no effect.
+ * The IBM z Systems port now supports target attributes and pragmas.
+ Please refer to the [18]documentation for details of available
+ attributes and pragmas as well as usage instructions.
+ * -fsplit-stack is now supported as part of the IBM z Systems port.
+ This feature requires a recent gold linker to be used.
+ * Support for the g5 and g6 -march=/-mtune= CPU level switches has
+ been deprecated and will be removed in a future GCC release. -m31
+ from now on defaults to -march=z900 if not specified otherwise.
+ -march=native on a g5/g6 machine will default to -march=z900.
SH
- * Minor improvements to code generated for integer arithmetic and
- code that involves the T bit.
- * Added support for the SH2A clips and clipu instructions. The
- compiler will now try to utilize them for min/max expressions such
- as max (-128, min (127, x)).
- * Added support for the cmp/str instruction through built-in
- functions such as __builtin_strlen. When not optimizing for size,
- the compiler will now expand calls to e.g. strlen as an inlined
- sequences which utilize the cmp/str instruction.
- * Improved code generated around volatile memory loads and stores.
- * The option -mcbranchdi has been deprecated. Specifying it will
- result in a warning and will not influence code generation.
- * The option -mcmpeqdi has been deprecated. Specifying it will result
- in a warning and will not influence code generation.
-
-GCC 4.9.1
-
- This is the [25]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.9.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Version 4.0 of the [26]OpenMP specification is supported even in
- Fortran, not just C and C++.
-
-GCC 4.9.2
-
- This is the [27]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.9.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [28]GCC manuals. If that fails, the
- [29]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [30]gcc at gcc.gnu.org. All of [31]our lists have public
- archives.
-
- Copyright (C) [32]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
+ * Support for SH5 / SH64 has been declared obsolete and will be
+ removed in future releases.
+ * Support for the FDPIC ABI has been added. It can be enabled using
+ the new -mfdpic target option and --enable-fdpic configure option.
- These pages are [33]maintained by the GCC team. Last modified
- 2015-04-08[34].
-
-References
+ SPARC
- 1. https://gcc.gnu.org/ml/gcc-patches/2013-05/msg00728.html
- 2. https://gcc.gnu.org/PR60825
- 3. https://gcc.gnu.org/gcc-4.9/porting_to.html
- 4. http://openmp.org/wp/openmp-specifications/
- 5. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Optimize-Options.html#index-fsimd-cost-model-908
- 6. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Language-Independent-Options.html#index-fdiagnostics-color-252
- 7. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Loop-Specific-Pragmas.html
- 8. https://www.cilkplus.org/
- 9. http://gcc.gnu.org/projects/cxx1y.html
- 10. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3638.html
- 11. http://gcc.gnu.org/projects/cxx1y.html
- 12. http://gcc.gnu.org/projects/cxx1y.html
- 13. http://gcc.gnu.org/projects/cxx1y.html
- 14. http://gcc.gnu.org/projects/cxx1y.html
- 15. http://gcc.gnu.org/projects/cxx1y.html
- 16. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3889.pdf
- 17. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/libstdc++/manual/manual/status.html#status.iso.2011
- 18. https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2014
- 19. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gfortran/Argument-passing-conventions.html
- 20. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gfortran/GNU-Fortran-Compiler-Directives.html
- 21. https://gcc.gnu.org/wiki/Fortran2003Status
- 22. https://gcc.gnu.org/wiki/Fortran2008Status
- 23. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gfortran/Debugging-Options.html
- 24. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Function-Multiversioning.html
- 25. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.9.1
- 26. http://openmp.org/wp/openmp-specifications/
- 27. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.9.2
- 28. https://gcc.gnu.org/onlinedocs/
- 29. mailto:gcc-help at gcc.gnu.org
- 30. mailto:gcc at gcc.gnu.org
- 31. https://gcc.gnu.org/lists.html
- 32. http://www.fsf.org/
- 33. https://gcc.gnu.org/about.html
- 34. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.8/index.html
- GCC 4.8 Release Series
+ * An ABI bug has been fixed in 64-bit mode. Unfortunately, this
+ change will break binary compatibility with earlier releases for
+ code it affects, but this should be pretty rare in practice. The
+ conditions are: a 16-byte structure containing a double or a 8-byte
+ vector in the second half is passed to a subprogram in slot #15,
+ for example as 16th parameter if the first 15 ones have at most 8
+ bytes. The double or vector was wrongly passed in floating-point
+ register %d32 in lieu of on the stack as per the SPARC calling
+ conventions.
- December 19, 2014
+Operating Systems
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.8.4.
+ Linux
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.8.3 relative to previous releases of GCC.
+ * Support for the [19]musl C library was added for the AArch64, ARM,
+ MicroBlaze, MIPS, MIPS64, PowerPC, PowerPC64, SH, i386, x32 and
+ x86_64 targets. It can be selected using the new -mmusl option in
+ case musl is not the default libc. GCC defaults to musl libc if it
+ is built with a target triplet matching the *-linux-musl* pattern.
-Release History
+ RTEMS
- GCC 4.8.4
- December 19, 2014 ([2]changes, [3]documentation)
+ * The RTEMS thread model implementation changed. Mutexes now use
+ self-contained objects defined in Newlib <sys/lock.h> instead of
+ Classic API semaphores. The keys for thread specific data and the
+ once function are directly defined via <pthread.h>. Self-contained
+ condition variables are provided via Newlib <sys/lock.h>. The RTEMS
+ thread model also supports C++11 threads.
+ * OpenMP support now uses self-contained objects provided by Newlib
+ <sys/lock.h> and offers a significantly better performance compared
+ to the POSIX configuration of libgomp. It is possible to configure
+ thread pools for each scheduler instance via the environment
+ variable GOMP_RTEMS_THREAD_POOLS.
- GCC 4.8.3
- May 22, 2014 ([4]changes, [5]documentation)
+ AIX
- GCC 4.8.2
- October 16, 2013 ([6]changes, [7]documentation)
+ * DWARF debugging support for AIX 7.1 has been enabled as an optional
+ debugging format. A more recent Technology Level (TL) and GCC built
+ with that level are required for full exploitation of DWARF
+ debugging capabilities.
- GCC 4.8.1
- May 31, 2013 ([8]changes, [9]documentation)
+ Solaris
- GCC 4.8.0
- March 22, 2013 ([10]changes, [11]documentation)
+ * Solaris 12 is now fully supported. Minimal support had already been
+ present in GCC 5.3.
+ * Solaris 12 provides a full set of startup files (crt1.o, crti.o,
+ crtn.o), which GCC now prefers over its own ones.
+ * Position independent executables (PIE) are now supported on Solaris
+ 12.
+ * Constructor priority is now supported on Solaris 12 with the system
+ linker.
+ * libvtv has been ported to Solaris 11 and up.
-References and Acknowledgements
+ Windows
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
+ * The option -mstackrealign is now automatically activated in 32-bit
+ mode whenever the use of SSE instructions is requested.
- A list of [12]successful builds is updated as new information becomes
- available.
+Other significant improvements
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [13]amazing group of volunteers is
- what makes GCC successful.
+ * The gcc and g++ driver programs will now provide suggestions for
+ misspelled command line options.
- For additional information about GCC please refer to the [14]GCC
- project web site or contact the [15]GCC development mailing list.
+$ gcc -static-libfortran test.f95
+gcc: error: unrecognized command line option '-static-libfortran'; did you mean
+'-static-libgfortran'?
- To obtain GCC please use [16]our mirror sites or [17]our SVN server.
+ * The --enable-default-pie configure option enables generation of PIE
+ by default.
For questions related to the use of GCC, please consult these web
- pages and the [18]GCC manuals. If that fails, the
- [19]gcc-help at gcc.gnu.org mailing list might help. Comments on these
+ pages and the [20]GCC manuals. If that fails, the
+ [21]gcc-help at gcc.gnu.org mailing list might help. Comments on these
web pages and the development of GCC are welcome on our developer
- list at [20]gcc at gcc.gnu.org. All of [21]our lists have public
+ list at [22]gcc at gcc.gnu.org. All of [23]our lists have public
archives.
- Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and
+ Copyright (C) [24]Free Software Foundation, Inc. Verbatim copying and
distribution of this entire article is permitted in any medium,
provided this notice is preserved.
- These pages are [23]maintained by the GCC team. Last modified
- 2014-12-19[24].
+ These pages are [25]maintained by the GCC team. Last modified
+ 2016-04-25[26].
References
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.8/changes.html
- 3. https://gcc.gnu.org/onlinedocs/4.8.4/
- 4. http://gcc.gnu.org/gcc-4.8/changes.html
- 5. https://gcc.gnu.org/onlinedocs/4.8.3/
- 6. http://gcc.gnu.org/gcc-4.8/changes.html
- 7. https://gcc.gnu.org/onlinedocs/4.8.2/
- 8. http://gcc.gnu.org/gcc-4.8/changes.html
- 9. https://gcc.gnu.org/onlinedocs/4.8.1/
- 10. http://gcc.gnu.org/gcc-4.8/changes.html
- 11. https://gcc.gnu.org/onlinedocs/4.8.0/
- 12. http://gcc.gnu.org/gcc-4.8/buildstat.html
- 13. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 14. http://gcc.gnu.org/index.html
- 15. mailto:gcc at gcc.gnu.org
- 16. http://gcc.gnu.org/mirrors.html
- 17. http://gcc.gnu.org/svn.html
- 18. https://gcc.gnu.org/onlinedocs/
- 19. mailto:gcc-help at gcc.gnu.org
- 20. mailto:gcc at gcc.gnu.org
- 21. https://gcc.gnu.org/lists.html
- 22. http://www.fsf.org/
- 23. https://gcc.gnu.org/about.html
- 24. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.8/changes.html
- GCC 4.8 Release Series
- Changes, New Features, and Fixes
-
-Caveats
-
- GCC now uses C++ as its implementation language. This means that to
- build GCC from sources, you will need a C++ compiler that understands
- C++ 2003. For more details on the rationale and specific changes,
- please refer to the [1]C++ conversion page.
-
- To enable the Graphite framework for loop optimizations you now need
- CLooG version 0.18.0 and ISL version 0.11.1. Both can be obtained from
- the [2]GCC infrastructure directory. The installation manual contains
- more information about requirements to build GCC.
-
- GCC now uses a more aggressive analysis to derive an upper bound for
- the number of iterations of loops using constraints imposed by language
- standards. This may cause non-conforming programs to no longer work as
- expected, such as SPEC CPU 2006 464.h264ref and 416.gamess. A new
- option, -fno-aggressive-loop-optimizations, was added to disable this
- aggressive analysis. In some loops that have known constant number of
- iterations, but undefined behavior is known to occur in the loop before
- reaching or during the last iteration, GCC will warn about the
- undefined behavior in the loop instead of deriving lower upper bound of
- the number of iterations for the loop. The warning can be disabled with
- -Wno-aggressive-loop-optimizations.
-
- On ARM, a bug has been fixed in GCC's implementation of the AAPCS rules
- for the layout of vectors that could lead to wrong code being
- generated. Vectors larger than 8 bytes in size are now by default
- aligned to an 8-byte boundary. This is an ABI change: code that makes
- explicit use of vector types may be incompatible with binary objects
- built with older versions of GCC. Auto-vectorized code is not affected
- by this change.
-
- On AVR, support has been removed for the command-line option
- -mshort-calls deprecated in GCC 4.7.
-
- On AVR, the configure option --with-avrlibc supported since GCC 4.7.2
- is turned on per default for all non-RTEMS configurations. This option
- arranges for a better integration of [3]AVR Libc with avr-gcc. For
- technical details, see [4]PR54461. To turn off the option in non-RTEMS
- configurations, use --with-avrlibc=no. If the compiler is configured
- for RTEMS, the option is always turned off.
-
- More information on porting to GCC 4.8 from previous versions of GCC
- can be found in the [5]porting guide for this release.
-
-General Optimizer Improvements (and Changes)
-
- * DWARF4 is now the default when generating DWARF debug information.
- When -g is used on a platform that uses DWARF debugging
- information, GCC will now default to -gdwarf-4
- -fno-debug-types-section.
- GDB 7.5, Valgrind 3.8.0 and elfutils 0.154 debug information
- consumers support DWARF4 by default. Before GCC 4.8 the default
- version used was DWARF2. To make GCC 4.8 generate an older DWARF
- version use -g together with -gdwarf-2 or -gdwarf-3. The default
- for Darwin and VxWorks is still -gdwarf-2 -gstrict-dwarf.
- * A new general optimization level, -Og, has been introduced. It
- addresses the need for fast compilation and a superior debugging
- experience while providing a reasonable level of run-time
- performance. Overall experience for development should be better
- than the default optimization level -O0.
- * A new option -ftree-partial-pre was added to control the partial
- redundancy elimination (PRE) optimization. This option is enabled
- by default at the -O3 optimization level, and it makes PRE more
- aggressive.
- * The option -fconserve-space has been removed; it was no longer
- useful on most targets since GCC supports putting variables into
- BSS without making them common.
- * The struct reorg and matrix reorg optimizations (command-line
- options -fipa-struct-reorg and -fipa-matrix-reorg) have been
- removed. They did not always work correctly, nor did they work with
- link-time optimization (LTO), hence were only applicable to
- programs consisting of a single translation unit.
- * Several scalability bottle-necks have been removed from GCC's
- optimization passes. Compilation of extremely large functions, e.g.
- due to the use of the flatten attribute in the "Eigen" C++ linear
- algebra templates library, is significantly faster than previous
- releases of GCC.
- * Link-time optimization (LTO) improvements:
- + LTO partitioning has been rewritten for better reliability and
- maintanibility. Several important bugs leading to link
- failures have been fixed.
- * Interprocedural optimization improvements:
- + A new symbol table has been implemented. It builds on existing
- callgraph and varpool modules and provide a new API. Unusual
- symbol visibilities and aliases are handled more consistently
- leading to, for example, more aggressive unreachable code
- removal with LTO.
- + The inline heuristic can now bypass limits on the size of of
- inlined functions when the inlining is particularly
- profitable. This happens, for example, when loop bounds or
- array strides get propagated.
- + Values passed through aggregates (either by value or
- reference) are now propagated at the inter-procedural level
- leading to better inlining decisions (for example in the case
- of Fortran array descriptors) and devirtualization.
- * [6]AddressSanitizer , a fast memory error detector, has been added
- and can be enabled via -fsanitize=address. Memory access
- instructions will be instrumented to detect heap-, stack-, and
- global-buffer overflow as well as use-after-free bugs. To get nicer
- stacktraces, use -fno-omit-frame-pointer. The AddressSanitizer is
- available on IA-32/x86-64/x32/PowerPC/PowerPC64 GNU/Linux and on
- x86-64 Darwin.
- * [7]ThreadSanitizer has been added and can be enabled via
- -fsanitize=thread. Instructions will be instrumented to detect data
- races. The ThreadSanitizer is available on x86-64 GNU/Linux.
- * A new local register allocator (LRA) has been implemented, which
- replaces the 26 year old reload pass and improves generated code
- quality. For now it is active on the IA-32 and x86-64 targets.
- * Support for transactional memory has been implemented on the
- following architectures: IA-32/x86-64, ARM, PowerPC, SH, SPARC, and
- Alpha.
-
-New Languages and Language specific improvements
-
- C family
-
- * Each diagnostic emitted now includes the original source line and a
- caret '^' indicating the column. The option
- -fno-diagnostics-show-caret suppresses this information.
- * The option -ftrack-macro-expansion=2 is now enabled by default.
- This allows the compiler to display the macro expansion stack in
- diagnostics. Combined with the caret information, an example
- diagnostic showing these two features is:
-
-t.c:1:94: error: invalid operands to binary < (have ‘struct mystruct’ and ‘float
-’)
- #define MYMAX(A,B) __extension__ ({ __typeof__(A) __a = (A); __typeof__(B) _
-_b = (B); __a < __b ? __b : __a; })
-
- ^
-t.c:7:7: note: in expansion of macro 'MYMAX'
- X = MYMAX(P, F);
- ^
-
- * A new -Wsizeof-pointer-memaccess warning has been added (also
- enabled by -Wall) to warn about suspicious length parameters to
- certain string and memory built-in functions if the argument uses
- sizeof. This warning warns e.g. about memset (ptr, 0, sizeof
- (ptr)); if ptr is not an array, but a pointer, and suggests a
- possible fix, or about memcpy (&foo, ptr, sizeof (&foo));.
- * The new option -Wpedantic is an alias for -pedantic, which is now
- deprecated. The forms -Wno-pedantic, -Werror=pedantic, and
- -Wno-error=pedantic work in the same way as for any other -W
- option. One caveat is that -Werror=pedantic is not equivalent to
- -pedantic-errors, since the latter makes into errors some warnings
- that are not controlled by -Wpedantic, and the former only affects
- diagnostics that are disabled when using -Wno-pedantic.
- * The option -Wshadow no longer warns if a declaration shadows a
- function declaration, unless the former declares a function or
- pointer to function, because this is [8]a common and valid case in
- real-world code.
-
- C++
-
- * G++ now implements the [9]C++11 thread_local keyword; this differs
- from the GNU __thread keyword primarily in that it allows dynamic
- initialization and destruction semantics. Unfortunately, this
- support requires a run-time penalty for references to
- non-function-local thread_local variables defined in a different
- translation unit even if they don't need dynamic initialization, so
- users may want to continue to use __thread for TLS variables with
- static initialization semantics.
- If the programmer can be sure that no use of the variable in a
- non-defining TU needs to trigger dynamic initialization (either
- because the variable is statically initialized, or a use of the
- variable in the defining TU will be executed before any uses in
- another TU), they can avoid this overhead with the
- -fno-extern-tls-init option.
- OpenMP threadprivate variables now also support dynamic
- initialization and destruction by the same mechanism.
- * G++ now implements the [10]C++11 attribute syntax, e.g.
-
-[[noreturn]] void f();
-
- and also the alignment specifier, e.g.
-
-alignas(double) int i;
-
- * G++ now implements [11]C++11 inheriting constructors, e.g.
-
-struct A { A(int); };
-struct B: A { using A::A; }; // defines B::B(int)
-B b(42); // OK
-
- * As of GCC 4.8.1, G++ implements the change to decltype semantics
- from [12]N3276.
-
-struct A f();
-decltype(f()) g(); // OK, return type of f() is not required to be complete.
-
- * As of GCC 4.8.1, G++ implements [13]C++11 ref-qualifiers, e.g.
-
-struct A { int f() &; };
-int i = A().f(); // error, f() requires an lvalue object
-
- * G++ now supports a -std=c++1y option for experimentation with
- features proposed for the next revision of the standard, expected
- around 2014. Currently the only difference from -std=c++11 is
- support for return type deduction in normal functions, as proposed
- in [14]N3386. Status of C++1y features in GCC 4.8 can be found
- [15]here.
- * The G++ namespace association extension, __attribute ((strong)),
- has been deprecated. Inline namespaces should be used instead.
- * G++ now supports a -fext-numeric-literal option to control whether
- GNU numeric literal suffixes are accepted as extensions or
- processed as C++11 user-defined numeric literal suffixes. The flag
- is on (use suffixes for GNU literals) by default for -std=gnu++*,
- and -std=c++98. The flag is off (use suffixes for user-defined
- literals) by default for -std=c++11 and later.
-
- Runtime Library (libstdc++)
-
- * [16]Improved experimental support for the new ISO C++ standard,
- C++11, including:
- + forward_list meets the allocator-aware container requirements;
- + this_thread::sleep_for(), this_thread::sleep_until() and
- this_thread::yield() are defined without requiring the
- configure option --enable-libstdcxx-time;
- * Improvements to <random>:
- + SSE optimized normal_distribution.
- + Use of hardware RNG instruction for random_device on new x86
- processors (requires the assembler to support the
- instruction.)
- and <ext/random>:
- + New random number engine simd_fast_mersenne_twister_engine
- with an optimized SSE implementation.
- + New random number distributions beta_distribution,
- normal_mv_distribution, rice_distribution,
- nakagami_distribution, pareto_distribution, k_distribution,
- arcsine_distribution, hoyt_distribution.
- * Added --disable-libstdcxx-verbose configure option to disable
- diagnostic messages issued when a process terminates abnormally.
- This may be useful for embedded systems to reduce the size of
- executables that link statically to the library.
-
- Fortran
-
- * Compatibility notice:
- + Module files: The version of module files (.mod) has been
- incremented. Fortran MODULEs compiled by earlier GCC versions
- have to be recompiled, when they are USEd by files compiled
- with GCC 4.8. GCC 4.8 is not able to read .mod files created
- by earlier versions; attempting to do so gives an error
- message.
- Note: The ABI of the produced assembler data itself has not
- changed; object files and libraries are fully compatible with
- older versions except as noted below.
- + ABI: Some internal names (used in the assembler/object file)
- have changed for symbols declared in the specification part of
- a module. If an affected module – or a file using it via use
- association – is recompiled, the module and all files which
- directly use such symbols have to be recompiled as well. This
- change only affects the following kind of module symbols:
- o Procedure pointers. Note: C-interoperable function
- pointers (type(c_funptr)) are not affected nor are
- procedure-pointer components.
- o Deferred-length character strings.
- * The [17]BACKTRACE intrinsic subroutine has been added. It shows a
- backtrace at an arbitrary place in user code; program execution
- continues normally afterwards.
- * The [18]-Wc-binding-type warning option has been added (disabled by
- default). It warns if the a variable might not be C interoperable;
- in particular, if the variable has been declared using an intrinsic
- type with default kind instead of using a kind parameter defined
- for C interoperability in the intrinsic ISO_C_Binding module.
- Before, this warning was always printed. The -Wc-binding-type
- option is enabled by -Wall.
- * The [19]-Wrealloc-lhs and -Wrealloc-lhs-all warning command-line
- options have been added, which diagnose when code is inserted for
- automatic (re)allocation of a variable during assignment. This
- option can be used to decide whether it is safe to use
- [20]-fno-realloc-lhs. Additionally, it can be used to find
- automatic (re)allocation in hot loops. (For arrays, replacing
- "var=" by "var(:)=" disables the automatic reallocation.)
- * The [21]-Wcompare-reals command-line option has been added. When
- this is set, warnings are issued when comparing REAL or COMPLEX
- types for equality and inequality; consider replacing a == b by
- abs(a−b) < eps with a suitable eps. -Wcompare-reals is enabled by
- -Wextra.
- * The [22]-Wtarget-lifetime command-line option has been added
- (enabled with -Wall), which warns if the pointer in a pointer
- assignment might outlive its target.
- * Reading floating point numbers which use "q" for the exponential
- (such as 4.0q0) is now supported as vendor extension for better
- compatibility with old data files. It is strongly recommended to
- use for I/O the equivalent but standard conforming "e" (such as
- 4.0e0).
- (For Fortran source code, consider replacing the "q" in
- floating-point literals by a kind parameter (e.g. 4.0e0_qp with a
- suitable qp). Note that – in Fortran source code – replacing "q" by
- a simple "e" is not equivalent.)
- * The GFORTRAN_TMPDIR environment variable for specifying a
- non-default directory for files opened with STATUS="SCRATCH", is
- not used anymore. Instead gfortran checks the POSIX/GNU standard
- TMPDIR environment variable. If TMPDIR is not defined, gfortran
- falls back to other methods to determine the directory for
- temporary files as documented in the [23]user manual.
- * [24]Fortran 2003:
- + Support for unlimited polymorphic variables (CLASS(*)) has
- been added. Nonconstant character lengths are not yet
- supported.
- * [25]TS 29113:
- + Assumed types (TYPE(*)) are now supported.
- + Experimental support for assumed-rank arrays (dimension(..))
- has been added. Note that currently gfortran's own array
- descriptor is used, which is different from the one defined in
- TS29113, see [26]gfortran's header file or use the [27]Chasm
- Language Interoperability Tools.
-
- Go
-
- * GCC 4.8.2 provides a complete implementation of the Go 1.1.2
- release.
- * GCC 4.8.0 and 4.8.1 implement a preliminary version of the Go 1.1
- release. The library support is not quite complete.
- * Go has been tested on GNU/Linux and Solaris platforms for various
- processors including x86, x86_64, PowerPC, SPARC, and Alpha. It may
- work on other platforms as well.
-
-New Targets and Target Specific Improvements
-
- AArch64
-
- * A new port has been added to support AArch64, the new 64-bit
- architecture from ARM. Note that this is a separate port from the
- existing 32-bit ARM port.
- * The port provides initial support for the Cortex-A53 and the
- Cortex-A57 processors with the command line options
- -mcpu=cortex-a53 and -mcpu=cortex-a57.
- * As of GCC 4.8.4 a workaround for the ARM Cortex-A53 erratum 835769
- has been added and can be enabled by giving the
- -mfix-cortex-a53-835769 option. Alternatively it can be enabled by
- default by configuring GCC with the --enable-fix-cortex-a53-835769
- option.
-
- ARM
-
- * Initial support has been added for the AArch32 extensions defined
- in the ARMv8 architecture.
- * Code generation improvements for the Cortex-A7 and Cortex-A15 CPUs.
- * A new option, -mcpu=marvell-pj4, has been added to generate code
- for the Marvell PJ4 processor.
- * The compiler can now automatically generate the VFMA, VFMS, REVSH
- and REV16 instructions.
- * A new vectorizer cost model for Advanced SIMD configurations to
- improve the auto-vectorization strategies used.
- * The scheduler now takes into account the number of live registers
- to reduce the amount of spilling that can occur. This should
- improve code performance in large functions. The limit can be
- removed by using the option -fno-sched-pressure.
- * Improvements have been made to the Marvell iWMMX code generation
- and support for the iWMMX2 SIMD unit has been added. The option
- -mcpu=iwmmxt2 can be used to enable code generation for the latter.
- * A number of code generation improvements for Thumb2 to reduce code
- size when compiling for the M-profile processors.
- * The RTEMS (arm-rtems) port has been updated to use the EABI.
- * Code generation support for the old FPA and Maverick floating-point
- architectures has been removed. Ports that previously relied on
- these features have also been removed. This includes the targets:
- + arm*-*-linux-gnu (use arm*-*-linux-gnueabi)
- + arm*-*-elf (use arm*-*-eabi)
- + arm*-*-uclinux* (use arm*-*-uclinux*eabi)
- + arm*-*-ecos-elf (no alternative)
- + arm*-*-freebsd (no alternative)
- + arm*-wince-pe* (no alternative).
-
- AVR
-
- * Support for the "Embedded C" fixed-point has been added. For
- details, see the [28]GCC wiki and the [29]user manual. The support
- is not complete.
- * A new print modifier %r for register operands in inline assembler
- is supported. It will print the raw register number without the
- register prefix 'r':
- /* Return the most significant byte of 'val', a 64-bit value. */
-
- unsigned char msb (long long val)
- {
- unsigned char c;
- __asm__ ("mov %0, %r1+7" : "=r" (c) : "r" (val));
- return c;
- }
- The inline assembler in this example will generate code like
- mov r24, 8+7
- provided c is allocated to R24 and val is allocated to R8…R15. This
- works because the GNU assembler accepts plain register numbers
- without register prefix.
- * Static initializers with 3-byte symbols are supported now:
- extern const __memx char foo;
- const __memx void *pfoo = &foo;
- This requires at least Binutils 2.23.
-
- IA-32/x86-64
-
- * Allow -mpreferred-stack-boundary=3 for the x86-64 architecture with
- SSE extensions disabled. Since the x86-64 ABI requires 16 byte
- stack alignment, this is ABI incompatible and intended to be used
- in controlled environments where stack space is an important
- limitation. This option will lead to wrong code when functions
- compiled with 16 byte stack alignment (such as functions from a
- standard library) are called with misaligned stack. In this case,
- SSE instructions may lead to misaligned memory access traps. In
- addition, variable arguments will be handled incorrectly for 16
- byte aligned objects (including x87 long double and __int128),
- leading to wrong results. You must build all modules with
- -mpreferred-stack-boundary=3, including any libraries. This
- includes the system libraries and startup modules.
- * Support for the new Intel processor codename Broadwell with RDSEED,
- ADCX, ADOX, PREFETCHW is available through -madx, -mprfchw,
- -mrdseed command-line options.
- * Support for the Intel RTM and HLE intrinsics, built-in functions
- and code generation is available via -mrtm and -mhle.
- * Support for the Intel FXSR, XSAVE and XSAVEOPT instruction sets.
- Intrinsics and built-in functions are available via -mfxsr, -mxsave
- and -mxsaveopt respectively.
- * New -maddress-mode=[short|long] options for x32.
- -maddress-mode=short overrides default 64-bit addresses to 32-bit
- by emitting the 0x67 address-size override prefix. This is the
- default address mode for x32.
- * New built-in functions to detect run-time CPU type and ISA:
- + A built-in function __builtin_cpu_is has been added to detect
- if the run-time CPU is of a particular type. It returns a
- positive integer on a match and zero otherwise. It accepts one
- string literal argument, the CPU name. For example,
- __builtin_cpu_is("westmere") returns a positive integer if the
- run-time CPU is an Intel Core i7 Westmere processor. Please
- refer to the [30]user manual for the list of valid CPU names
- recognized.
- + A built-in function __builtin_cpu_supports has been added to
- detect if the run-time CPU supports a particular ISA feature.
- It returns a positive integer on a match and zero otherwise.
- It accepts one string literal argument, the ISA feature. For
- example, __builtin_cpu_supports("ssse3") returns a positive
- integer if the run-time CPU supports SSSE3 instructions.
- Please refer to the [31]user manual for the list of valid ISA
- names recognized.
- Caveat: If these built-in functions are called before any static
- constructors are invoked, like during IFUNC initialization, then
- the CPU detection initialization must be explicitly run using this
- newly provided built-in function, __builtin_cpu_init. The
- initialization needs to be done only once. For example, this is how
- the invocation would look like inside an IFUNC initializer:
- static void (*some_ifunc_resolver(void))(void)
- {
- __builtin_cpu_init();
- if (__builtin_cpu_is("amdfam10h") ...
- if (__builtin_cpu_supports("popcnt") ...
- }
-
- * Function Multiversioning Support with G++:
- It is now possible to create multiple function versions each
- targeting a specific processor and/or ISA. Function versions have
- the same signature but different target attributes. For example,
- here is a program with function versions:
- __attribute__ ((target ("default")))
- int foo(void)
- {
- return 1;
- }
-
- __attribute__ ((target ("sse4.2")))
- int foo(void)
- {
- return 2;
- }
-
- int main (void)
- {
- int (*p) = &foo;
- assert ((*p)() == foo());
- return 0;
- }
-
- Please refer to this [32]wiki for more information.
- * The x86 back end has been improved to allow option -fschedule-insns
- to work reliably. This option can be used to schedule instructions
- better and leads to improved performace in certain cases.
- * Windows MinGW-w64 targets (*-w64-mingw*) require at least r5437
- from the Mingw-w64 trunk.
- * Support for new AMD family 15h processors (Steamroller core) is now
- available through the -march=bdver3 and -mtune=bdver3 options.
- * Support for new AMD family 16h processors (Jaguar core) is now
- available through the -march=btver2 and -mtune=btver2 options.
-
- FRV
-
- * This target now supports the -fstack-usage command-line option.
-
- MIPS
-
- * GCC can now generate code specifically for the R4700, Broadcom XLP
- and MIPS 34kn processors. The associated -march options are
- -march=r4700, -march=xlp and -march=34kn respectively.
- * GCC now generates better DSP code for MIPS 74k cores thanks to
- further scheduling optimizations.
- * The MIPS port now supports the -fstack-check option.
- * GCC now passes the -mmcu and -mno-mcu options to the assembler.
- * Previous versions of GCC would silently accept -fpic and -fPIC for
- -mno-abicalls targets like mips*-elf. This combination was not
- intended or supported, and did not generate position-independent
- code. GCC 4.8 now reports an error when this combination is used.
-
- PowerPC / PowerPC64 / RS6000
-
- * SVR4 configurations (GNU/Linux, FreeBSD, NetBSD) no longer save,
- restore or update the VRSAVE register by default. The respective
- operating systems manage the VRSAVE register directly.
- * Large TOC support has been added for AIX through the command line
- option -mcmodel=large.
- * Native Thread-Local Storage support has been added for AIX.
- * VMX (Altivec) and VSX instruction sets now are enabled implicitly
- when targetting processors that support those hardware features on
- AIX 6.1 and above.
-
- RX
-
- * This target will now issue a warning message whenever multiple fast
- interrupt handlers are found in the same compilation unit. This
- feature can be turned off by the new
- -mno-warn-multiple-fast-interrupts command-line option.
-
- S/390, System z
-
- * Support for the IBM zEnterprise zEC12 processor has been added.
- When using the -march=zEC12 option, the compiler will generate code
- making use of the following new instructions:
- + load and trap instructions
- + 2 new compare and trap instructions
- + rotate and insert selected bits - without CC clobber
- The -mtune=zEC12 option enables zEC12 specific instruction
- scheduling without making use of new instructions.
- * Register pressure sensitive instruction scheduling is enabled by
- default.
- * The ifunc function attribute is enabled by default.
- * memcpy and memcmp invokations on big memory chunks or with run time
- lengths are not generated inline anymore when tuning for z10 or
- higher. The purpose is to make use of the IFUNC optimized versions
- in Glibc.
-
- SH
-
- * The default alignment settings have been reduced to be less
- aggressive. This results in more compact code for optimization
- levels other than -Os.
- * Improved support for the __atomic built-in functions:
- + A new option -matomic-model=model selects the model for the
- generated atomic sequences. The following models are
- supported:
-
- soft-gusa
- Software gUSA sequences (SH3* and SH4* only). On
- SH4A targets this will now also partially utilize
- the movco.l and movli.l instructions. This is the
- default when the target is sh3*-*-linux* or
- sh4*-*-linux*.
-
- hard-llcs
- Hardware movco.l / movli.l sequences (SH4A only).
-
- soft-tcb
- Software thread control block sequences.
-
- soft-imask
- Software interrupt flipping sequences (privileged
- mode only). This is the default when the target is
- sh1*-*-linux* or sh2*-*-linux*.
-
- none
- Generates function calls to the respective __atomic
- built-in functions. This is the default for SH64
- targets or when the target is not sh*-*-linux*.
-
- + The option -msoft-atomic has been deprecated. It is now an
- alias for -matomic-model=soft-gusa.
- + A new option -mtas makes the compiler generate the tas.b
- instruction for the __atomic_test_and_set built-in function
- regardless of the selected atomic model.
- + The __sync functions in libgcc now reflect the selected atomic
- model when building the toolchain.
- * Added support for the mov.b and mov.w instructions with
- displacement addressing.
- * Added support for the SH2A instructions movu.b and movu.w.
- * Various improvements to code generated for integer arithmetic.
- * Improvements to conditional branches and code that involves the T
- bit. A new option -mzdcbranch tells the compiler to favor
- zero-displacement branches. This is enabled by default for SH4*
- targets.
- * The pref instruction will now be emitted by the __builtin_prefetch
- built-in function for SH3* targets.
- * The fmac instruction will now be emitted by the fmaf standard
- function and the __builtin_fmaf built-in function.
- * The -mfused-madd option has been deprecated in favor of the
- machine-independent -ffp-contract option. Notice that the fmac
- instruction will now be generated by default for expressions like a
- * b + c. This is due to the compiler default setting
- -ffp-contract=fast.
- * Added new options -mfsrra and -mfsca to allow the compiler using
- the fsrra and fsca instructions on targets other than SH4A (where
- they are already enabled by default).
- * Added support for the __builtin_bswap32 built-in function. It is
- now expanded as a sequence of swap.b and swap.w instructions
- instead of a library function call.
- * The behavior of the -mieee option has been fixed and the negative
- form -mno-ieee has been added to control the IEEE conformance of
- floating point comparisons. By default -mieee is now enabled and
- the option -ffinite-math-only implicitly sets -mno-ieee.
- * Added support for the built-in functions __builtin_thread_pointer
- and __builtin_set_thread_pointer. This assumes that GBR is used to
- hold the thread pointer of the current thread. Memory loads and
- stores relative to the address returned by __builtin_thread_pointer
- will now also utilize GBR based displacement address modes.
- * The -mdiv= option for targets other than SHmedia has been fixed and
- documented.
-
- SPARC
-
- * Added optimized instruction scheduling for Niagara4.
-
- TILE-Gx
-
- * Added support for the -mcmodel=MODEL command-line option. The
- models supported are small and large.
-
- V850
-
- * This target now supports the E3V5 architecture via the use of the
- new -mv850e3v5 command-line option. It also has experimental
- support for the e3v5 LOOP instruction which can be enabled via the
- new -mloop command-line option.
-
- XStormy16
-
- * This target now supports the -fstack-usage command-line option.
-
-Operating Systems
-
- Windows (Cygwin)
-
- * Executables are now linked against shared libgcc by default. The
- previous default was to link statically, which can still be done by
- explicitly specifying -static or static-libgcc on the command line.
- However it is strongly advised against, as it will cause problems
- for any application that makes use of DLLs compiled by GCC. It
- should be alright for a monolithic stand-alone application that
- only links against the Windows DLLs, but offers little or no
- benefit.
-
-GCC 4.8.1
-
- This is the [33]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.8.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- The C++11 <chrono> std::chrono::system_clock and
- std::chrono::steady_clock classes have changed ABI in GCC 4.8.1, they
- both are now separate (never typedefs of each other), both use
- std::chrono::nanoseconds resolution, on most GNU/Linux configurations
- std::chrono::steady_clock is now finally monotonic, and both classes
- are mangled differently than in the previous GCC releases.
- std::chrono::system_clock::now() with std::chrono::microseconds resp.
- std::chrono::seconds resolution is still exported for backwards
- compatibility with default configured libstdc++. Note that libstdc++
- configured with --enable-libstdcxx-time= used to be ABI incompatible
- with default configured libstdc++ for those two classes and no ABI
- compatibility can be offered for those configurations, so any C++11
- code that uses those classes and has been compiled and linked against
- libstdc++ configured with the non-default --enable-libstdcxx-time=
- configuration option needs to be recompiled.
-
-GCC 4.8.2
-
- This is the [34]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.8.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.8.3
-
- This is the [35]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.8.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Support for the new powerpc64le-linux platform has been added. It
- defaults to generating code that conforms to the ELFV2 ABI.
-
-GCC 4.8.4
-
- This is the [36]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.8.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [37]GCC manuals. If that fails, the
- [38]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [39]gcc at gcc.gnu.org. All of [40]our lists have public
- archives.
-
- Copyright (C) [41]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [42]maintained by the GCC team. Last modified
- 2015-04-20[43].
-
-References
-
- 1. https://gcc.gnu.org/wiki/cxx-conversion
- 2. ftp://gcc.gnu.org/pub/gcc/infrastructure/
- 3. http://www.nongnu.org/avr-libc/
- 4. https://gcc.gnu.org/PR54461
- 5. https://gcc.gnu.org/gcc-4.8/porting_to.html
- 6. https://code.google.com/p/address-sanitizer/
- 7. https://code.google.com/p/data-race-test/wiki/ThreadSanitizer
- 8. https://lkml.org/lkml/2006/11/28/239
- 9. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html
- 10. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html
- 11. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html
- 12. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3276.pdf
- 13. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html
- 14. http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2012/n3386.html
- 15. http://gcc.gnu.org/projects/cxx1y.html
- 16. https://gcc.gnu.org/onlinedocs/gcc-4.8.4/libstdc++/manual/manual/status.html#status.iso.2011
- 17. https://gcc.gnu.org/onlinedocs/gfortran/BACKTRACE.html
- 18. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html
- 19. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html
- 20. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html
- 21. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html
- 22. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html
- 23. https://gcc.gnu.org/onlinedocs/gfortran/TMPDIR.html
- 24. https://gcc.gnu.org/wiki/Fortran2003Status
- 25. https://gcc.gnu.org/wiki/TS29113Status
- 26. https://gcc.gnu.org/viewcvs/trunk/libgfortran/libgfortran.h?content-type=text/plain&view=co
- 27. http://chasm-interop.sourceforge.net/
- 28. https://gcc.gnu.org/wiki/avr-gcc#Fixed-Point_Support
- 29. https://gcc.gnu.org/onlinedocs/gcc/Fixed-Point.html
- 30. https://gcc.gnu.org/onlinedocs/gcc/X86-Built-in-Functions.html#X86-Built-in-Functions
- 31. https://gcc.gnu.org/onlinedocs/gcc/X86-Built-in-Functions.html#X86-Built-in-Functions
- 32. https://gcc.gnu.org/wiki/FunctionMultiVersioning
- 33. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.1
- 34. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.2
- 35. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.3
- 36. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.4
- 37. https://gcc.gnu.org/onlinedocs/
- 38. mailto:gcc-help at gcc.gnu.org
- 39. mailto:gcc at gcc.gnu.org
- 40. https://gcc.gnu.org/lists.html
- 41. http://www.fsf.org/
- 42. https://gcc.gnu.org/about.html
- 43. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.7/index.html
- GCC 4.7 Release Series
-
- June 12, 2014
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.7.4.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.7.3 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.7.4
- June 12, 2014 ([2]changes, [3]documentation)
-
- GCC 4.7.3
- April 11, 2013 ([4]changes, [5]documentation)
-
- GCC 4.7.2
- September 20, 2012 ([6]changes, [7]documentation)
-
- GCC 4.7.1
- June 14, 2012 ([8]changes, [9]documentation)
-
- GCC 4.7.0
- March 22, 2012 ([10]changes, [11]documentation)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [12]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [13]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [14]GCC
- project web site or contact the [15]GCC development mailing list.
-
- To obtain GCC please use [16]our mirror sites or [17]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [18]GCC manuals. If that fails, the
- [19]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [20]gcc at gcc.gnu.org. All of [21]our lists have public
- archives.
-
- Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [23]maintained by the GCC team. Last modified
- 2014-06-12[24].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.7/changes.html
- 3. https://gcc.gnu.org/onlinedocs/4.7.4/
- 4. http://gcc.gnu.org/gcc-4.7/changes.html
- 5. https://gcc.gnu.org/onlinedocs/4.7.3/
- 6. http://gcc.gnu.org/gcc-4.7/changes.html
- 7. https://gcc.gnu.org/onlinedocs/4.7.2/
- 8. http://gcc.gnu.org/gcc-4.7/changes.html
- 9. https://gcc.gnu.org/onlinedocs/4.7.1/
- 10. http://gcc.gnu.org/gcc-4.7/changes.html
- 11. https://gcc.gnu.org/onlinedocs/4.7.0/
- 12. http://gcc.gnu.org/gcc-4.7/buildstat.html
- 13. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 14. http://gcc.gnu.org/index.html
- 15. mailto:gcc at gcc.gnu.org
- 16. http://gcc.gnu.org/mirrors.html
- 17. http://gcc.gnu.org/svn.html
- 18. https://gcc.gnu.org/onlinedocs/
- 19. mailto:gcc-help at gcc.gnu.org
- 20. mailto:gcc at gcc.gnu.org
- 21. https://gcc.gnu.org/lists.html
- 22. http://www.fsf.org/
- 23. https://gcc.gnu.org/about.html
- 24. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.7/changes.html
- GCC 4.7 Release Series
- Changes, New Features, and Fixes
-
-Caveats
-
- * The -fconserve-space flag has been deprecated. The flag had no
- effect for most targets: only targets without a global .bss section
- and without support for switchable sections. Furthermore, the flag
- only had an effect for G++, where it could result in wrong
- semantics (please refer to the GCC manual for further details). The
- flag will be removed in GCC 4.8
- * Support for a number of older systems and recently unmaintained or
- untested target ports of GCC has been declared obsolete in GCC 4.7.
- Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
- All GCC ports for the following processor architectures have been
- declared obsolete:
- + picoChip (picochip-*)
- The following ports for individual systems on particular
- architectures have been obsoleted:
- + IRIX 6.5 (mips-sgi-irix6.5)
- + MIPS OpenBSD (mips*-*-openbsd*)
- + Solaris 8 (*-*-solaris2.8). Details can be found in the
- [1]announcement.
- + Tru64 UNIX V5.1 (alpha*-dec-osf5.1*)
- * On ARM, when compiling for ARMv6 (but not ARMv6-M), ARMv7-A,
- ARMv7-R, or ARMv7-M, the new option -munaligned-access is active by
- default, which for some sources generates code that accesses memory
- on unaligned addresses. This requires the kernel of those systems
- to enable such accesses (controlled by CP15 register c1, refer to
- ARM documentation). Alternatively, or for compatibility with
- kernels where unaligned accesses are not supported, all code has to
- be compiled with -mno-unaligned-access. Upstream Linux kernel
- releases have automatically and unconditionally supported unaligned
- accesses as emitted by GCC due to this option being active since
- version 2.6.28.
- * Support on ARM for the legacy floating-point accelerator (FPA) and
- the mixed-endian floating-point format that it used has been
- obsoleted. The ports that still use this format have been obsoleted
- as well. Many legacy ARM ports already provide an alternative that
- uses the VFP floating-point format. The obsolete ports will be
- deleted in the next release.
- The obsolete ports with alternatives are:
- + arm*-*-rtems (use arm*-*-rtemseabi)
- + arm*-*-linux-gnu (use arm*-*-linux-gnueabi)
- + arm*-*-elf (use arm*-*-eabi)
- + arm*-*-uclinux* (use arm*-*-uclinux*eabi)
- Note, however, that these alternatives are not binary compatible
- with their legacy counterparts (although some can support running
- legacy applications).
- The obsolete ports that currently lack a modern alternative are:
- + arm*-*-ecos-elf
- + arm*-*-freebsd
- + arm*-wince-pe*
- New ports that support more recent versions of the architecture are
- welcome.
- * Support for the Maverick co-processor on ARM has been obsoleted.
- Code to support it will be deleted in the next release.
- * Support has been removed for Unix International threads on Solaris
- 2, so the --enable-threads=solaris configure option and the
- -threads compiler option don't work any longer.
- * Support has been removed for the Solaris BSD Compatibility Package,
- which lives in /usr/ucbinclude and /usr/ucblib. It has been removed
- from Solaris 11, and was only intended as a migration aid from
- SunOS 4 to SunOS 5. The -compat-bsd compiler option is not
- recognized any longer.
- * The AVR port's libgcc has been improved and its multilib structure
- has been enhanced. As a result, all objects contributing to an
- application must either be compiled with GCC versions up to 4.6.x
- or with GCC versions 4.7.1 or later. If the compiler is used with
- AVR Libc, you need a version that supports the new layout, i.e.
- implements [2]#35407.
- * The AVR port's -mshort-calls command-line option has been
- deprecated. It will be removed in the GCC 4.8 release. See -mrelax
- for a replacement.
- * The AVR port only references startup code that clears .bss and the
- common section resp. initializes the .data and .rodata section
- provided respective sections (or subsections thereof) are not
- empty, see [3]PR18145. Applications that put all static storage
- objects into non-standard sections and / or define all static
- storage objects in assembler modules, must reference __do_clear_bss
- resp. __do_copy_data by hand or undefine the symbol(s) by means of
- -Wl,-u,__do_clear_bss resp. -Wl,-u,__do_copy_data.
- * The ARM port's -mwords-little-endian option has been deprecated. It
- will be removed in a future release.
- * Support has been removed for the NetWare x86 configuration
- obsoleted in GCC 4.6.
- * It is no longer possible to use the "l" constraint in MIPS16 asm
- statements.
- * GCC versions 4.7.0 and 4.7.1 had changes to the C++ standard
- library which affected the ABI in C++11 mode: a data member was
- added to std::list changing its size and altering the definitions
- of some member functions, and std::pair's move constructor was
- non-trivial which altered the calling convention for functions with
- std::pair arguments or return types. The ABI incompatibilities have
- been fixed for GCC version 4.7.2 but as a result C++11 code
- compiled with GCC 4.7.0 or 4.7.1 may be incompatible with C++11
- code compiled with different GCC versions and with C++98/C++03 code
- compiled with any version.
- * On ARM, a bug has been fixed in GCC's implementation of the AAPCS
- rules for the layout of vectors that could lead to wrong code being
- generated. Vectors larger than 8 bytes in size are now by default
- aligned to an 8-byte boundary. This is an ABI change: code that
- makes explicit use of vector types may be incompatible with binary
- objects built with older versions of GCC. Auto-vectorized code is
- not affected by this change. (This change affects GCC versions
- 4.7.2 and later.)
- * More information on porting to GCC 4.7 from previous versions of
- GCC can be found in the [4]porting guide for this release.
-
-General Optimizer Improvements
-
- * Support for a new parameter --param case-values-threshold=n was
- added to allow users to control the cutoff between doing switch
- statements as a series of if statements and using a jump table.
- * Link-time optimization (LTO) improvements:
- + Improved scalability and reduced memory usage. Link time
- optimization of Firefox now requires 3GB of RAM on a 64-bit
- system, while over 8GB was needed previously. Linking time has
- been improved, too. The serial stage of linking Firefox has
- been sped up by about a factor of 10.
- + Reduced size of object files and temporary storage used during
- linking.
- + Streaming performance (both outbound and inbound) has been
- improved.
- + ld -r is now supported with LTO.
- + Several bug fixes, especially in symbol table handling and
- merging.
- * Interprocedural optimization improvements:
- + Heuristics now take into account that after inlining code will
- be optimized out because of known values (or properties) of
- function parameters. For example:
-void foo(int a)
-{
- if (a > 10)
- ... huge code ...
-}
-void bar (void)
-{
- foo (0);
-}
-
- The call of foo will be inlined into bar even when optimizing
- for code size. Constructs based on __builtin_constant_p are
- now understood by the inliner and code size estimates are
- evaluated a lot more realistically.
- + The representation of C++ virtual thunks and aliases (both
- implicit and defined via the alias attribute) has been
- re-engineered. Aliases no longer pose optimization barriers
- and calls to an alias can be inlined and otherwise optimized.
- + The inter-procedural constant propagation pass has been
- rewritten. It now performs generic function specialization.
- For example when compiling the following:
-void foo(bool flag)
-{
- if (flag)
- ... do something ...
- else
- ... do something else ...
-}
-void bar (void)
-{
- foo (false);
- foo (true);
- foo (false);
- foo (true);
- foo (false);
- foo (true);
-}
-
- GCC will now produce two copies of foo. One with flag being
- true, while other with flag being false. This leads to
- performance improvements previously possible only by inlining
- all calls. Cloning causes a lot less code size growth.
- * A string length optimization pass has been added. It attempts to
- track string lengths and optimize various standard C string
- functions like strlen, strchr, strcpy, strcat, stpcpy and their
- _FORTIFY_SOURCE counterparts into faster alternatives. This pass is
- enabled by default at -O2 or above, unless optimizing for size, and
- can be disabled by the -fno-optimize-strlen option. The pass can
- e.g. optimize
-char *bar (const char *a)
-{
- size_t l = strlen (a) + 2;
- char *p = malloc (l); if (p == NULL) return p;
- strcpy (p, a); strcat (p, "/"); return p;
-}
-
- into:
-char *bar (const char *a)
-{
- size_t tmp = strlen (a);
- char *p = malloc (tmp + 2); if (p == NULL) return p;
- memcpy (p, a, tmp); memcpy (p + tmp, "/", 2); return p;
-}
-
- or for hosted compilations where stpcpy is available in the runtime
- and headers provide its prototype, e.g.
-void foo (char *a, const char *b, const char *c, const char *d)
-{
- strcpy (a, b); strcat (a, c); strcat (a, d);
-}
-
- can be optimized into:
-void foo (char *a, const char *b, const char *c, const char *d)
-{
- strcpy (stpcpy (stpcpy (a, b), c), d);
-}
-
-New Languages and Language specific improvements
-
- * Version 3.1 of the [5]OpenMP specification is now supported for the
- C, C++, and Fortran compilers.
-
- Ada
-
- * The command-line option -feliminate-unused-debug-types has been
- re-enabled by default, as it is for the other languages, leading to
- a reduction in debug info size of 12.5% and more for relevant
- cases, as well as to a small compilation speedup.
-
- C family
-
- * A new built-in, __builtin_assume_aligned, has been added, through
- which the compiler can be hinted about pointer alignment and can
- use it to improve generated code.
- * A new warning option -Wunused-local-typedefs was added for C, C++,
- Objective-C and Objective-C++. This warning diagnoses typedefs
- locally defined in a function, and otherwise not used.
- * A new experimental command-line option -ftrack-macro-expansion was
- added for C, C++, Objective-C, Objective-C++ and Fortran. It allows
- the compiler to emit diagnostic about the current macro expansion
- stack when a compilation error occurs in a macro expansion.
- * Experimental support for transactional memory has been added. It
- includes support in the compiler, as well as a supporting runtime
- library called libitm. To compile code with transactional memory
- constructs, use the -fgnu-tm option.
- Support is currently available for Alpha, ARM, PowerPC, SH, SPARC,
- and 32-bit/64-bit x86 platforms.
- For more details on transactional memory see [6]the GCC WiKi.
- * Support for atomic operations specifying the C++11/C11 memory model
- has been added. These new __atomic routines replace the existing
- __sync built-in routines.
- Atomic support is also available for memory blocks. Lock-free
- instructions will be used if a memory block is the same size and
- alignment as a supported integer type. Atomic operations which do
- not have lock-free support are left as function calls. A set of
- library functions is available on the GCC atomic wiki in the
- "External Atomics Library" section.
- For more details on the memory models and features, see the
- [7]atomic wiki.
- * When a binary operation is performed on vector types and one of the
- operands is a uniform vector, it is possible to replace the vector
- with the generating element. For example:
-typedef int v4si __attribute__ ((vector_size (16)));
-v4si res, a = {1,2,3,4};
-int x;
-
-res = 2 + a; /* means {2,2,2,2} + a */
-res = a - x; /* means a - {x,x,x,x} */
-
- C
-
- * There is support for some more features from the C11 revision of
- the ISO C standard. GCC now accepts the options -std=c11 and
- -std=gnu11, in addition to the previous -std=c1x and -std=gnu1x.
- + Unicode strings (previously supported only with options such
- as -std=gnu11, now supported with -std=c11), and the
- predefined macros __STDC_UTF_16__ and __STDC_UTF_32__.
- + Nonreturning functions (_Noreturn and <stdnoreturn.h>).
- + Alignment support (_Alignas, _Alignof, max_align_t,
- <stdalign.h>).
- + A built-in function __builtin_complex is provided to support C
- library implementation of the CMPLX family of macros.
-
- C++
-
- * G++ now accepts the -std=c++11, -std=gnu++11, and -Wc++11-compat
- options, which are equivalent to -std=c++0x, -std=gnu++0x, and
- -Wc++0x-compat, respectively.
- * G++ now implements [8]C++11 extended friend syntax:
-
-template<class W>
-class Q
-{
- static const int I = 2;
-public:
- friend W;
-};
-
-struct B
-{
- int ar[Q<B>::I];
-};
-
- * Thanks to Ville Voutilainen, G++ now implements [9]C++11 explicit
- override control.
-
-struct B {
- virtual void f() const final;
- virtual void f(int);
-};
-
-struct D : B {
- void f() const; // error: D::f attempts to override final B::f
- void f(long) override; // error: doesn't override anything
- void f(int) override; // ok
-};
-
-struct E final { };
-struct F: E { }; // error: deriving from final class
-
- * G++ now implements [10]C++11 non-static data member initializers.
-
-struct A {
- int i = 42;
-} a; // initializes a.i to 42
-
- * Thanks to Ed Smith-Rowland, G++ now implements [11]C++11
- user-defined literals.
-
-// Not actually a good approximation. :)
-constexpr long double operator"" _degrees (long double d) { return d * 0.0175; }
-long double pi = 180.0_degrees;
-
- * G++ now implements [12]C++11 alias-declarations.
-
-template <class T> using Ptr = T*;
-Ptr<int> ip; // decltype(ip) is int*
-
- * Thanks to Ville Voutilainen and Pedro Lamarão, G++ now implements
- [13]C++11 delegating constructors.
-
-struct A {
- A(int);
- A(): A(42) { } // delegate to the A(int) constructor
-};
-
- * G++ now fully implements C++11 atomic classes rather than just
- integer derived classes.
-
-class POD {
- int a;
- int b;
-};
-std::atomic<POD> my_atomic_POD;
-
- * G++ now sets the predefined macro __cplusplus to the correct value,
- 199711L for C++98/03, and 201103L for C++11.
- * G++ now correctly implements the two-phase lookup rules such that
- an unqualified name used in a template must have an appropriate
- declaration found either in scope at the point of definition of the
- template or by argument-dependent lookup at the point of
- instantiation. As a result, code that relies on a second
- unqualified lookup at the point of instantiation to find functions
- declared after the template or in dependent bases will be rejected.
- The compiler will suggest ways to fix affected code, and using the
- -fpermissive compiler flag will allow the code to compile with a
- warning.
-
-template <class T>
-void f() { g(T()); } // error, g(int) not found by argument-dependent lookup
-void g(int) { } // fix by moving this declaration before the declaration of f
-
-template <class T>
-struct A: T {
- // error, B::g(B) not found by argument-dependent lookup
- void f() { g(T()); } // fix by using this->g or A::g
-};
-
-struct B { void g(B); };
-
-int main()
-{
- f<int>();
- A<B>().f();
-}
-
- * G++ now properly re-uses stack space allocated for temporary
- objects when their lifetime ends, which can significantly lower
- stack consumption for some C++ functions. As a result of this, some
- code with undefined behavior will now break:
-
-const int &f(const int &i) { return i; }
-....
-const int &x = f(1);
-const int &y = f(2);
-
- Here, x refers to the temporary allocated to hold the 1 argument,
- which only lives until the end of the initialization; it
- immediately becomes a dangling reference. So the next statement
- re-uses the stack slot to hold the 2 argument, and users of x get
- that value instead.
- Note that this should not cause any change of behavior for
- temporaries of types with non-trivial destructors, as they are
- already destroyed at end of full-expression; the change is that now
- the storage is released as well.
- * A new command-line option -Wdelete-non-virtual-dtor has been added
- to warn when delete is used to destroy an instance of a class which
- has virtual functions and non-virtual destructor. It is unsafe to
- delete an instance of a derived class through a pointer to a base
- class if the base class does not have a virtual destructor. This
- warning is enabled by -Wall.
- * A new command-line option -Wzero-as-null-pointer-constant has been
- added to warn when a literal '0' is used as null pointer constant.
- It can be useful to facilitate the conversion to nullptr in C++11.
- * As per C++98, access-declarations are now deprecated by G++.
- Using-declarations are to be used instead. Furthermore, some
- efforts have been made to improve the support of class scope
- using-declarations. In particular, using-declarations referring to
- a dependent type now work as expected ([14]bug c++/14258).
- * The ELF symbol visibility of a template instantiation is now
- properly constrained by the visibility of its template arguments
- ([15]bug c++/35688).
-
- Runtime Library (libstdc++)
-
- * [16]Improved experimental support for the new ISO C++ standard,
- C++11, including:
- + using noexcept in most of the library;
- + implementations of pointer_traits, allocator_traits and
- scoped_allocator_adaptor;
- + uses-allocator construction for tuple;
- + vector meets the allocator-aware container requirements;
- + replacing monotonic_clock with steady_clock;
- + enabling the thread support library on most POSIX targets;
- + many small improvements to conform to the FDIS.
- * Added --enable-clocale=newlib configure option.
- * Debug Mode iterators for unordered associative containers.
- * Avoid polluting the global namespace and do not include <unistd.h>.
-
- Fortran
-
- * The compile flag [17]-fstack-arrays has been added, which causes
- all local arrays to be put on stack memory. For some programs this
- will improve the performance significantly. If your program uses
- very large local arrays, it is possible that you will have to
- extend your runtime limits for stack memory.
- * The [18]-Ofast flag now also implies [19]-fno-protect-parens and
- [20]-fstack-arrays.
- * Front-end optimizations can now be selected by the
- [21]-ffrontend-optimize option and deselected by the
- -fno-frontend-optimize option.
- * When front-end optimization removes a function call,
- [22]-Wfunction-elimination warns about that.
- * When performing front-end-optimization, the
- [23]-faggressive-function-elimination option allows the removal of
- duplicate function calls even for impure functions.
- * The flag [24]-Wreal-q-constant has been added, which warns if
- floating-point literals have been specified using q (such as
- 1.0q0); the q marker is now supported as a vendor extension to
- denote quad precision (REAL(16) or, if not available, REAL(10)).
- Consider using a kind parameter (such as in 1.0_qp) instead, which
- can be obtained via [25]SELECTED_REAL_KIND.
- * The GFORTRAN_USE_STDERR environment variable has been removed. GNU
- Fortran now always prints error messages to standard error. If you
- wish to redirect standard error, please consult the manual for your
- OS, shell, batch environment etc. as appropriate.
- * The -fdump-core option and GFORTRAN_ERROR_DUMPCORE environment
- variable have been removed. When encountering a serious error,
- gfortran will now always abort the program. Whether a core dump is
- generated depends on the user environment settings; see the ulimit
- -c setting for POSIX shells, limit coredumpsize for C shells, and
- the [26]WER user-mode dumps settings on Windows.
- * The [27]-fbacktrace option is now enabled by default. When
- encountering a fatal error, gfortran will attempt to print a
- backtrace to standard error before aborting. It can be disabled
- with -fno-backtrace. Note: On POSIX targets with the addr2line
- utility from GNU binutils, GNU Fortran can print a backtrace with
- function name, file name, line number information in addition to
- the addresses; otherwise only the addresses are printed.
- * [28]Fortran 2003:
- + Generic interface names which have the same name as derived
- types are now supported, which allows to write constructor
- functions. Note that Fortran does not support static
- constructor functions; only default initialization or an
- explicit structure-constructor initialization are available.
- + [29]Polymorphic (class) arrays are now supported.
- * [30]Fortran 2008:
- + Support for the DO CONCURRENT construct has been added, which
- allows the user to specify that individual loop iterations
- have no interdependencies.
- + [31]Coarrays: Full single-image support except for polymorphic
- coarrays. Additionally, preliminary support for multiple
- images via an MPI-based [32]coarray communication library has
- been added. Note: The library version is not yet usable as
- remote coarray access is not yet possible.
- * [33]TS 29113:
- + New flag [34]-std=f2008ts permits programs that are expected
- to conform to the Fortran 2008 standard and the draft
- Technical Specification (TS) 29113 on Further Interoperability
- of Fortran with C.
- + The OPTIONAL attribute is now allowed for dummy arguments of
- BIND(C) procedures.
- + The RANK intrinsic has been added.
- + The implementation of the ASYNCHRONOUS attribute in GCC is
- compatible with the candidate draft of TS 29113 (since GCC
- 4.6).
-
- Go
-
- * GCC 4.7 implements the [35]Go 1 language standard. The library
- support in 4.7.0 is not quite complete, due to release timing.
- Release 4.7.1 includes complete support for Go 1. The Go library is
- from the Go 1.0.1 release.
- * Go has been tested on GNU/Linux and Solaris platforms. It may work
- on other platforms as well.
-
-New Targets and Target Specific Improvements
-
- ARM
-
- * GCC now supports the Cortex-A7 processor implementing the v7-a
- version of the architecture using the option -mcpu=cortex-a7.
- * The default vector size in auto-vectorization for NEON is now 128
- bits. If vectorization fails thusly, the vectorizer tries again
- with 64-bit vectors.
- * A new option -mvectorize-with-neon-double was added to allow users
- to change the vector size to 64 bits.
-
- AVR
-
- * GCC now supports the XMEGA architecture. This requires GNU binutils
- 2.22 or later.
- * Support for the [36]named address spaces __flash, __flash1, …,
- __flash5 and __memx has been added. These address spaces locate
- read-only data in flash memory and allow reading from flash memory
- by means of ordinary C code, i.e. without the need of (inline)
- assembler code:
-
-const __flash int values[] = { 42, 31 };
-
-int add_values (const __flash int *p, int i)
-{
- return values[i] + *p;
-}
-
- * Support has been added for the AVR-specific configure option
- --with-avrlibc=yes in order to arrange for better integration of
- [37]AVR-Libc. This configure option is supported in avr-gcc 4.7.2
- and newer and will only take effect in non-RTEMS configurations. If
- avr-gcc is configured for RTEMS, the option will be ignored which
- is the same as specifying --with-avrlibc=no. See [38]PR54461 for
- more technical details.
- * Support for AVR-specific [39]built-in functions has been added.
- * Support has been added for the signed and unsigned 24-bit scalar
- integer types __int24 and __uint24.
- * New command-line options -maccumulate-args, -mbranch-cost=cost and
- -mstrict-X were added to allow better fine-tuning of code
- optimization.
- * The command option -fdata-sections now also takes affect on the
- section names of variables with the progmem attribute.
- * A new inline assembler print modifier %i to print a RAM address as
- I/O address has been added:
-
-#include <avr/io.h> /* Port Definitions from AVR-LibC */
-
-void set_portb (uint8_t value)
-{
- asm volatile ("out %i0, %1" :: "n" (&PORTB), "r" (value) : "memory");
-}
-
- The offset between an I/O address and the RAM address for that I/O
- location is device-specific. This offset is taken into account when
- printing a RAM address with the %i modifier so that the address is
- suitable to be used as operand in an I/O command. The address must
- be a constant integer known at compile time.
- * The inline assembler constraint "R" to represent integers in the
- range −6 … 5 has been removed without replacement.
- * Many optimizations to:
- + 64-bit integer arithmetic
- + Widening multiplication
- + Integer division by a constant
- + Avoid constant reloading in multi-byte instructions.
- + Micro-optimizations for special instruction sequences.
- + Generic built-in functions like __builtin_ffs*,
- __builtin_clz*, etc.
- + If-else decision trees generated by switch instructions
- + Merging of data located in flash memory
- + New libgcc variants for devices with 8-bit wide stack pointer
- + …
- * Better documentation:
- + Handling of EIND and indirect jumps on devices with more than
- 128 KiB of program memory.
- + Handling of the RAMPD, RAMPX, RAMPY and RAMPZ special function
- registers.
- + Function attributes OS_main and OS_task.
- + AVR-specific built-in macros.
-
- C6X
-
- * Support has been added for the Texas Instruments C6X family of
- processors.
-
- CR16
-
- * Support has been added for National Semiconductor's CR16
- architecture.
-
- Epiphany
-
- * Support has been added for Adapteva's Epiphany architecture.
-
- IA-32/x86-64
-
- * Support for Intel AVX2 intrinsics, built-in functions and code
- generation is available via -mavx2.
- * Support for Intel BMI2 intrinsics, built-in functions and code
- generation is available via -mbmi2.
- * Implementation and automatic generation of __builtin_clz* using the
- lzcnt instruction is available via -mlzcnt.
- * Support for Intel FMA3 intrinsics and code generation is available
- via -mfma.
- * A new -mfsgsbase command-line option is available that makes GCC
- generate new segment register read/write instructions through
- dedicated built-ins.
- * Support for the new Intel rdrnd instruction is available via
- -mrdrnd.
- * Two additional AVX vector conversion instructions are available via
- -mf16c.
- * Support for new Intel processor codename IvyBridge with RDRND,
- FSGSBASE and F16C is available through -march=core-avx-i.
- * Support for the new Intel processor codename Haswell with AVX2,
- FMA, BMI, BMI2, LZCNT is available through -march=core-avx2.
- * Support for new AMD family 15h processors (Piledriver core) is now
- available through -march=bdver2 and -mtune=bdver2 options.
- * Support for [40]the x32 psABI is now available through the -mx32
- option.
- * Windows mingw targets are using the -mms-bitfields option by
- default.
- * Windows x86 targets are using the __thiscall calling convention for
- C++ class-member functions.
- * Support for the configure option --with-threads=posix for Windows
- mingw targets.
-
- MIPS
-
- * GCC now supports thread-local storage (TLS) for MIPS16. This
- requires GNU binutils 2.22 or later.
- * GCC can now generate code specifically for the Cavium Octeon+ and
- Octeon2 processors. The associated command-line options are
- -march=octeon+ and -march=octeon2 respectively. Both options
- require GNU binutils 2.22 or later.
- * GCC can now work around certain 24k errata, under the control of
- the command-line option -mfix-24k. These workarounds require GNU
- binutils 2.20 or later.
- * 32-bit MIPS GNU/Linux targets such as mips-linux-gnu can now build
- n32 and n64 multilibs. The result is effectively a 64-bit GNU/Linux
- toolchain that generates 32-bit code by default. Use the
- configure-time option --enable-targets=all to select these extra
- multilibs.
- * Passing -fno-delayed-branch now also stops the assembler from
- automatically filling delay slots.
-
- PowerPC/PowerPC64
-
- * Vectors of type vector long long or vector long are passed and
- returned using the same method as other vectors with the VSX
- instruction set. Previously GCC did not adhere to the ABI for
- 128-bit vectors with 64-bit integer base types (PR 48857). This
- will also be fixed in the GCC 4.6.1 and 4.5.4 releases.
- * A new option -mno-pointers-to-nested-functions was added to allow
- AIX 32-bit/64-bit and GNU/Linux 64-bit PowerPC users to specify
- that the compiler should not load up the chain register (r11)
- before calling a function through a pointer. If you use this
- option, you cannot call nested functions through a pointer, or call
- other languages that might use the static chain.
- * A new option msave-toc-indirect was added to allow AIX
- 32-bit/64-bit and GNU/Linux 64-bit PowerPC users control whether we
- save the TOC in the prologue for indirect calls or generate the
- save inline. This can speed up some programs that call through a
- function pointer a lot, but it can slow down other functions that
- only call through a function pointer in exceptional cases.
- * The PowerPC port will now enable machine-specific built-in
- functions when the user switches the target machine using the
- #pragma GCC target or __attribute__ ((__target__ ("target"))) code
- sequences. In addition, the target macros are updated. However, due
- to the way the -save-temps switch is implemented, you won't see the
- effect of these additional macros being defined in preprocessor
- output.
-
- SH
-
- * A new option -msoft-atomic has been added. When it is specified,
- GCC will generate GNU/Linux-compatible gUSA atomic sequences for
- the new __atomic routines.
- * Since it is neither supported by GAS nor officially documented,
- code generation for little endian SH2A has been disabled.
- Specifying -ml with -m2a* will now result in a compiler error.
- * The defunct -mbranch-cost option has been fixed.
- * Some improvements to the generated code of:
- + Utilization of the tst #imm,R0 instruction.
- + Dynamic shift instructions on SH2A.
- + Integer absolute value calculations.
- * The -mdiv= option for targets other than SHmedia has been fixed and
- documented.
-
- SPARC
-
- * The option -mflat has been reinstated. When it is specified, the
- compiler will generate code for a single register window model.
- This is essentially a new implementation and the corresponding
- debugger support has been added to GDB 7.4.
- * Support for the options -mtune=native and -mcpu=native has been
- added on selected native platforms (GNU/Linux and Solaris).
- * Support for the SPARC T3 (Niagara 3) processor has been added.
- * VIS:
- + An intrinsics header visintrin.h has been added.
- + Builtin intrinsics for the VIS 1.0 edge handling and pixel
- compare instructions have been added.
- + The little-endian version of alignaddr is now supported.
- + When possible, VIS builtins are marked const, which should
- increase the compiler's ability to optimize VIS operations.
- + The compiler now properly tracks the %gsr register and how it
- behaves as an input for various VIS instructions.
- + Akin to fzero, the compiler can now generate fone instructions
- in order to set all of the bits of a floating-point register
- to 1.
- + The documentation for the VIS intrinsics in the GCC manual has
- been brought up to date and many inaccuracies were fixed.
- + Intrinsics for the VIS 2.0 bmask, bshuffle, and
- non-condition-code setting edge instructions have been added.
- Their availability is controlled by the new -mvis2 and
- -mno-vis2 options. They are enabled by default on
- UltraSPARC-III and later CPUs.
- * Support for UltraSPARC Fused Multiply-Add floating-point extensions
- has been added. These instructions are enabled by default on SPARC
- T3 (Niagara 3) and later CPUs.
-
- TILE-Gx/TILEPro
-
- * Support has been added for the Tilera TILE-Gx and TILEPro families
- of processors.
-
-Other significant improvements
-
- * A new option (-grecord-gcc-switches) was added that appends
- compiler command-line options that might affect code generation to
- the DW_AT_producer attribute string in the DWARF debugging
- information.
- * GCC now supports various new GNU extensions to the DWARF debugging
- information format, like [41]entry value and [42]call site
- information, [43]typed DWARF stack or [44]a more compact macro
- representation. Support for these extensions has been added to GDB
- 7.4. They can be disabled through the -gstrict-dwarf command-line
- option.
-
-GCC 4.7.1
-
- This is the [45]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.7.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- The Go frontend in the 4.7.1 release fully supports the [46]Go 1
- language standard.
-
-GCC 4.7.2
-
- This is the [47]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.7.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.7.3
-
- This is the [48]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.7.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.7.4
-
- This is the [49]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.7.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [50]GCC manuals. If that fails, the
- [51]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [52]gcc at gcc.gnu.org. All of [53]our lists have public
- archives.
-
- Copyright (C) [54]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [55]maintained by the GCC team. Last modified
- 2014-12-06[56].
-
-References
-
- 1. https://gcc.gnu.org/ml/gcc-patches/2011-03/msg01263.html
- 2. http://savannah.nongnu.org/bugs/?35407
- 3. https://gcc.gnu.org/PR18145
- 4. https://gcc.gnu.org/gcc-4.7/porting_to.html
- 5. http://openmp.org/wp/openmp-specifications/
- 6. https://gcc.gnu.org/wiki/TransactionalMemory
- 7. https://gcc.gnu.org/wiki/Atomic/GCCMM
- 8. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html
- 9. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html
- 10. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html
- 11. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html
- 12. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html
- 13. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html
- 14. https://gcc.gnu.org/PR14258
- 15. https://gcc.gnu.org/PR35688
- 16. https://gcc.gnu.org/onlinedocs/gcc-4.7.4/libstdc++/manual/manual/status.html#status.iso.2011
- 17. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfstack-arrays_007d-254
- 18. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Optimize-Options.html#index-Ofast-689
- 19. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfno-protect-parens_007d-270
- 20. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfstack-arrays_007d-254
- 21. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfrontend-optimize_007d-275
- 22. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Error-and-Warning-Options.html#index-g_t_0040code_007bWfunction-elimination_007d-170
- 23. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfaggressive-function-elimination_007d-270
- 24. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Error-and-Warning-Options.html#index-g_t_0040code_007bWreal-q-constant_007d-149
- 25. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/SELECTED_005fREAL_005fKIND.html
- 26. http://msdn.microsoft.com/en-us/library/bb787181(v=vs.85).aspx
- 27. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Debugging-Options.html#index-g_t_0040code_007bfno-backtrace_007d-183
- 28. https://gcc.gnu.org/wiki/Fortran2003Status
- 29. https://gcc.gnu.org/wiki/OOP
- 30. https://gcc.gnu.org/wiki/Fortran2008Status
- 31. https://gcc.gnu.org/wiki/Coarray
- 32. https://gcc.gnu.org/wiki/CoarrayLib
- 33. https://gcc.gnu.org/wiki/TS29113Status
- 34. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Fortran-Dialect-Options.html#index-g_t_0040code_007bstd_003d_007d_0040var_007bstd_007d-option-53
- 35. http://weekly.golang.org/doc/go1.html
- 36. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Named-Address-Spaces.html
- 37. http://nongnu.org/avr-libc/
- 38. https://gcc.gnu.org/PR54461
- 39. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/AVR-Built_002din-Functions.html
- 40. https://sites.google.com/site/x32abi/
- 41. http://www.dwarfstd.org/ShowIssue.php?issue=100909.1
- 42. http://www.dwarfstd.org/ShowIssue.php?issue=100909.2
- 43. http://www.dwarfstd.org/doc/040408.1.html
- 44. http://www.dwarfstd.org/ShowIssue.php?issue=110722.1
- 45. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.1
- 46. http://weekly.golang.org/doc/go1.html
- 47. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.2
- 48. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.3
- 49. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.4
- 50. https://gcc.gnu.org/onlinedocs/
- 51. mailto:gcc-help at gcc.gnu.org
- 52. mailto:gcc at gcc.gnu.org
- 53. https://gcc.gnu.org/lists.html
- 54. http://www.fsf.org/
- 55. https://gcc.gnu.org/about.html
- 56. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.6/index.html
- GCC 4.6 Release Series
-
- April 12, 2013
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.6.4.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.6.3 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.6.4
- April 12, 2013 ([2]changes, [3]documentation)
-
- GCC 4.6.3
- March 1, 2012 ([4]changes, [5]documentation)
-
- GCC 4.6.2
- October 26, 2011 ([6]changes, [7]documentation)
-
- GCC 4.6.1
- June 27, 2011 ([8]changes, [9]documentation)
-
- GCC 4.6.0
- March 25, 2011 ([10]changes, [11]documentation)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [12]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [13]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [14]GCC
- project web site or contact the [15]GCC development mailing list.
-
- To obtain GCC please use [16]our mirror sites or [17]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [18]GCC manuals. If that fails, the
- [19]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [20]gcc at gcc.gnu.org. All of [21]our lists have public
- archives.
-
- Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [23]maintained by the GCC team. Last modified
- 2014-06-28[24].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.6/changes.html
- 3. https://gcc.gnu.org/onlinedocs/4.6.4/
- 4. http://gcc.gnu.org/gcc-4.6/changes.html
- 5. https://gcc.gnu.org/onlinedocs/4.6.3/
- 6. http://gcc.gnu.org/gcc-4.6/changes.html
- 7. https://gcc.gnu.org/onlinedocs/4.6.2/
- 8. http://gcc.gnu.org/gcc-4.6/changes.html
- 9. https://gcc.gnu.org/onlinedocs/4.6.1/
- 10. http://gcc.gnu.org/gcc-4.6/changes.html
- 11. https://gcc.gnu.org/onlinedocs/4.6.0/
- 12. http://gcc.gnu.org/gcc-4.6/buildstat.html
- 13. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 14. http://gcc.gnu.org/index.html
- 15. mailto:gcc at gcc.gnu.org
- 16. http://gcc.gnu.org/mirrors.html
- 17. http://gcc.gnu.org/svn.html
- 18. https://gcc.gnu.org/onlinedocs/
- 19. mailto:gcc-help at gcc.gnu.org
- 20. mailto:gcc at gcc.gnu.org
- 21. https://gcc.gnu.org/lists.html
- 22. http://www.fsf.org/
- 23. https://gcc.gnu.org/about.html
- 24. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.6/changes.html
- GCC 4.6 Release Series
- Changes, New Features, and Fixes
-
-Caveats
-
- * The options -b <machine> and -V <version> have been removed because
- they were unreliable. Instead, users should directly run
- <machine>-gcc when cross-compiling, or <machine>-gcc-<version> to
- run a different version of gcc.
- * GCC now has stricter checks for invalid command-line options. In
- particular, when gcc was called to link object files rather than
- compile source code, it would previously accept and ignore all
- options starting with --, including linker options such as
- --as-needed and --export-dynamic, although such options would
- result in errors if any source code was compiled. Such options, if
- unknown to the compiler, are now rejected in all cases; if the
- intent was to pass them to the linker, options such as
- -Wl,--as-needed should be used.
- * Versions of the GNU C library up to and including 2.11.1 included
- an [1]incorrect implementation of the cproj function. GCC optimizes
- its builtin cproj according to the behavior specified and allowed
- by the ISO C99 standard. If you want to avoid discrepancies between
- the C library and GCC's builtin transformations when using cproj in
- your code, use GLIBC 2.12 or later. If you are using an older GLIBC
- and actually rely on the incorrect behavior of cproj, then you can
- disable GCC's transformations using -fno-builtin-cproj.
- * The C-only intermodule optimization framework (IMA, enabled by
- -combine) has been removed in favor of the new generic link-time
- optimization framework (LTO) introduced in [2]GCC 4.5.0.
- * GCC now ships with the LGPL-licensed libquadmath library, which
- provides quad-precision mathematical functions for targets with a
- __float128 datatype. __float128 is available for targets on 32-bit
- x86, x86-64 and Itanium architectures. The libquadmath library is
- automatically built on such targets when building the Fortran
- compiler.
- * New -Wunused-but-set-variable and -Wunused-but-set-parameter
- warnings were added for C, C++, Objective-C and Objective-C++.
- These warnings diagnose variables respective parameters which are
- only set in the code and never otherwise used. Usually such
- variables are useless and often even the value assigned to them is
- computed needlessly, sometimes expensively. The
- -Wunused-but-set-variable warning is enabled by default by -Wall
- flag and -Wunused-but-set-parameter by -Wall -Wextra flags.
- * On ARM, a bug has been fixed in GCC's implementation of the AAPCS
- rules for the layout of vectors that could lead to wrong code being
- generated. Vectors larger than 8 bytes in size are now by default
- aligned to an 8-byte boundary. This is an ABI change: code that
- makes explicit use of vector types may be incompatible with binary
- objects built with older versions of GCC. Auto-vectorized code is
- not affected by this change. (This change affects GCC versions
- 4.6.4 and later, with the exception of versions 4.7.0 and 4.7.1.)
- * On AVR, variables with the progmem attribute to locate data in
- flash memory must be qualified as const.
- * Support for a number of older systems and recently unmaintained or
- untested target ports of GCC has been declared obsolete in GCC 4.6.
- Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
- All GCC ports for the following processor architectures have been
- declared obsolete:
- + Argonaut ARC (arc-*)
- + National Semiconductor CRX (crx-*)
- + Motorola 68HC11 and 68HC12 (m68hc11-*-*, m6811-*-*,
- m68hc12-*-*, m6812-*-*)
- + Sunplus S+core (score-*)
- The following ports for individual systems on particular
- architectures have been obsoleted:
- + Interix (i[34567]86-*-interix3*)
- + NetWare x86 (i[3456x]86-*-netware*)
- + Generic ARM PE (arm-*-pe* other than arm*-wince-pe*)
- + MCore PE (mcore-*-pe*)
- + SH SymbianOS (sh*-*-symbianelf*)
- + GNU Hurd on Alpha and PowerPC (alpha*-*-gnu*, powerpc*-*-gnu*)
- + M68K uClinux old ABI (m68k-*-uclinuxoldabi*)
- + a.out NetBSD (arm*-*-netbsd*, i[34567]86-*-netbsd*,
- vax-*-netbsd*, but not *-*-netbsdelf*)
- The i[34567]86-*-pe alias for Cygwin targets has also been
- obsoleted; users should configure for i[34567]86-*-cygwin* instead.
- Certain configure options to control the set of libraries built
- with GCC on some targets have been obsoleted. On ARM targets, the
- options --disable-fpu, --disable-26bit, --disable-underscore,
- --disable-interwork, --disable-biendian and --disable-nofmult have
- been obsoleted. On MIPS targets, the options
- --disable-single-float, --disable-biendian and --disable-softfloat
- have been obsoleted.
- * Support has been removed for all the [3]configurations obsoleted in
- GCC 4.5.
- * More information on porting to GCC 4.6 from previous versions of
- GCC can be found in the [4]porting guide for this release.
-
-General Optimizer Improvements
-
- * A new general optimization level, -Ofast, has been introduced. It
- combines the existing optimization level -O3 with options that can
- affect standards compliance but result in better optimized code.
- For example, -Ofast enables -ffast-math.
- * Link-time optimization improvements:
- + The [5]Scalable Whole Program Optimizer (WHOPR) project has
- stabilized to the point of being usable. It has become the
- default mode when using the LTO optimization model. Link time
- optimization can now split itself into multiple parallel
- compilations. Parallelism is controlled with -flto=n (where n
- specifies the number of compilations to execute in parallel).
- GCC can also cooperate with a GNU make job server by
- specifying the -flto=jobserver option and adding + to the
- beginning of the Makefile rule executing the linker.
- Classical LTO mode can be enforced by -flto-partition=none.
- This may result in small code quality improvements.
- + A large number of bugs were fixed. GCC itself, Mozilla Firefox
- and other large applications can be built with LTO enabled.
- + The linker plugin support improvements
- o Linker plugin is now enabled by default when the linker
- is detected to have plugin support. This is the case for
- GNU ld 2.21.51 or newer (on ELF and Cygwin targets) and
- the Gold linker on ELF targets. Plugin support of the
- Apple linker on Darwin is not compatible with GCC. The
- linker plugin can also be controlled by the
- -fuse-linker-plugin command line option.
- o Resolution information from the linker plugin is used to
- drive whole program assumptions. Use of the linker plugin
- results in more aggressive optimization on binaries and
- on shared libraries that use the hidden visibility
- attribute. Consequently the use of -fwhole-program is not
- necessary in addition to LTO.
- + Hidden symbols used from non-LTO objects now have to be
- explicitly annotated with externally_visible when the linker
- plugin is not used.
- + C++ inline functions and virtual tables are now privatized
- more aggressively, leading to better inter-procedural
- optimization and faster dynamic linking.
- + Memory usage and intermediate language streaming performance
- have been improved.
- + Static constructors and destructors from individual units are
- inlined into a single function. This can significantly improve
- startup times of large C++ applications where static
- constructors are very common. For example, static constructors
- are used when including the iostream header.
- + Support for the Ada language has been added.
- * Interprocedural optimization improvements
- + The interprocedural framework was re-tuned for link time
- optimization. Several scalability issues were resolved.
- + Improved auto-detection of const and pure functions. Newly,
- noreturn functions are auto-detected.
- The [6]-Wsuggest-attribute=[const|pure|noreturn] flag is
- available that informs users when adding attributes to headers
- might improve code generation.
- + A number of inlining heuristic improvements. In particular:
- o Partial inlining is now supported and enabled by default
- at -O2 and greater. The feature can be controlled via
- -fpartial-inlining.
- Partial inlining splits functions with short hot path to
- return. This allows more aggressive inlining of the hot
- path leading to better performance and often to code size
- reductions (because cold parts of functions are not
- duplicated).
- o Scalability for large compilation units was improved
- significantly.
- o Inlining of callbacks is now more aggressive.
- o Virtual methods are considered for inlining when the
- caller is inlined and devirtualization is then possible.
- o Inlining when optimizing for size (either in cold regions
- of a program or when compiling with -Os) was improved to
- better handle C++ programs with larger abstraction
- penalty, leading to smaller and faster code.
- + The IPA reference optimization pass detecting global variables
- used or modified by functions was strengthened and sped up.
- + Functions whose address was taken are now optimized out when
- all references to them are dead.
- + A new inter-procedural static profile estimation pass detects
- functions that are executed once or unlikely to be executed.
- Unlikely executed functions are optimized for size. Functions
- executed once are optimized for size except for the inner
- loops.
- + On most targets with named section support, functions used
- only at startup (static constructors and main), functions used
- only at exit and functions detected to be cold are placed into
- separate text segment subsections. This extends the
- -freorder-functions feature and is controlled by the same
- switch. The goal is to improve the startup time of large C++
- programs.
- Proper function placement requires linker support. GNU ld
- 2.21.51 on ELF targets was updated to place those functions
- together within the text section leading to better code
- locality and faster startup times of large C++ programs. The
- feature is also supported in the Apple linker. Support in the
- gold linker is planned.
- * A new switch -fstack-usage has been added. It makes the compiler
- output stack usage information for the program, on a per-function
- basis, in an auxiliary file.
- * A new switch -fcombine-stack-adjustments has been added. It can be
- used to enable or disable the compiler's stack-slot combining pass
- which before was enabled automatically at -O1 and above, but could
- not be controlled on its own.
- * A new switch -fstrict-volatile-bitfields has been added. Using it
- indicates that accesses to volatile bitfields should use a single
- access of the width of the field's type. This option can be useful
- for precisely defining and accessing memory-mapped peripheral
- registers from C or C++.
-
-Compile time and memory usage improvements
-
- * Datastructures used by the dataflow framework in GCC were
- reorganized for better memory usage and more cache locality.
- Compile time is improved especially on units with large functions
- (possibly resulting from a lot of inlining) not fitting into the
- processor cache. The compile time of the GCC C compiler binary with
- link-time optimization went down by over 10% (benchmarked on x86-64
- target).
-
-New Languages and Language specific improvements
-
- Ada
-
- * Stack checking has been improved on selected architectures (Alpha,
- IA-32/x86-64, RS/6000 and SPARC): it now will detect stack
- overflows in all cases on these architectures.
- * Initial support for Ada 2012 has been added.
-
- C family
-
- * A new warning, enabled by -Wdouble-promotion, has been added that
- warns about cases where a value of type float is implicitly
- promoted to double. This is especially helpful for CPUs that handle
- the former in hardware, but emulate the latter in software.
- * A new function attribute leaf was introduced. This attribute allows
- better inter-procedural optimization across calls to functions that
- return to the current unit only via returning or exception
- handling. This is the case for most library functions that have no
- callbacks.
- * Support for a new data type __int128 for targets having wide enough
- machine-mode support.
- * The new function attribute callee_pop_aggregate allows to specify
- if the caller or callee is responsible for popping the aggregate
- return pointer value from the stack.
- * Support for selectively enabling and disabling warnings via #pragma
- GCC diagnostic has been added. For instance:
-#pragma GCC diagnostic error "-Wuninitialized"
- foo(a); /* error is given for this one */
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wuninitialized"
- foo(b); /* no diagnostic for this one */
-#pragma GCC diagnostic pop
- foo(c); /* error is given for this one */
-#pragma GCC diagnostic pop
- foo(d); /* depends on command line options */
-
- * The -fmax-errors=N option is now supported. Using this option
- causes the compiler to exit after N errors have been issued.
-
- C
-
- * There is now experimental support for some features from the
- upcoming C1X revision of the ISO C standard. This support may be
- selected with -std=c1x, or -std=gnu1x for C1X with GNU extensions.
- Note that this support is experimental and may change incompatibly
- in future releases for consistency with changes to the C1X standard
- draft. The following features are newly supported as described in
- the N1539 draft of C1X (with changes agreed at the March 2011 WG14
- meeting); some other features were already supported with no
- compiler changes being needed, or have some support but not in full
- accord with N1539 (as amended).
- + Static assertions (_Static_assert keyword)
- + Typedef redefinition
- + New macros in <float.h>
- + Anonymous structures and unions
- * The new -fplan9-extensions option directs the compiler to support
- some extensions for anonymous struct fields which are implemented
- by the Plan 9 compiler. A pointer to a struct may be automatically
- converted to a pointer to an anonymous field when calling a
- function, in order to make the types match. An anonymous struct
- field whose type is a typedef name may be referred to using the
- typedef name.
-
- C++
-
- * Improved [7]experimental support for the upcoming C++0x ISO C++
- standard, including support for constexpr (thanks to Gabriel Dos
- Reis and Jason Merrill), nullptr (thanks to Magnus Fromreide),
- noexcept, unrestricted unions, range-based for loops (thanks to
- Rodrigo Rivas Costa), opaque enum declarations (thanks also to
- Rodrigo), implicitly deleted functions and implicit move
- constructors.
- * When an extern declaration within a function does not match a
- declaration in the enclosing context, G++ now properly declares the
- name within the namespace of the function rather than the namespace
- which was open just before the function definition ([8]c++/43145).
- * GCC now warns by default when casting integers to larger pointer
- types. These warnings can be disabled with the option
- -Wno-int-to-pointer-cast, which is now also available in C++.
- * G++ no longer optimizes using the assumption that a value of
- enumeration type will fall within the range specified by the
- standard, since that assumption is easily violated with a
- conversion from integer type ([9]c++/43680). The old behavior can
- be restored with -fstrict-enums.
- * The new -fnothrow-opt flag changes the semantics of a throw()
- exception specification to match the proposed semantics of the
- noexcept specification: just call terminate if an exception tries
- to propagate out of a function with such an exception
- specification. This dramatically reduces or eliminates the code
- size overhead from adding the exception specification.
- * The new -Wnoexcept flag will suggest adding a noexcept qualifier to
- a function that the compiler can tell doesn't throw if it would
- change the value of a noexcept expression.
- * The -Wshadow option now warns if a local variable or type
- declaration shadows another type in C++. Note that the compiler
- will not warn if a local variable shadows a struct/class/enum, but
- will warn if it shadows an explicit typedef.
- * When an identifier is not found in the current scope, G++ now
- offers suggestions about which identifier might have been intended.
- * G++ now issues clearer diagnostics for missing semicolons after
- class, struct, and union definitions.
- * G++ now issues clearer diagnostics for missing semicolons after
- class member declarations.
- * G++ now issues clearer diagnostics when a colon is used in a place
- where a double-colon was intended.
- * G++ no longer accepts mutable on reference members ([10]c++/33558).
- Use -fpermissive to allow the old, non-conforming behaviour.
- * A few mangling fixes have been made, to attribute const/volatile on
- function pointer types, decltype of a plain decl, and use of a
- function parameter in the declaration of another parameter. By
- default the compiler still uses the old mangling, but emits aliases
- with the new mangling on targets that support strong aliases. Users
- can switch over entirely to the new mangling with -fabi-version=5
- or -fabi-version=0. -Wabi will now warn about code that uses the
- old mangling.
- * In 4.6.0 and 4.6.1 G++ no longer allows objects of const-qualified
- type to be default initialized unless the type has a user-declared
- default constructor. In 4.6.2 G++ implements the proposed
- resolution of [11]DR 253, so default initialization is allowed if
- it initializes all subobjects. Code that fails to compile can be
- fixed by providing an initializer e.g.
- struct A { A(); };
- struct B : A { int i; };
- const B b = B();
- Use -fpermissive to allow the old, non-conforming behaviour.
-
- Runtime Library (libstdc++)
-
- * [12]Improved experimental support for the upcoming ISO C++
- standard, C++0x, including using constexpr and nullptr.
- * Performance improvements to the [13]Debug Mode, thanks to François
- Dumont.
- * Atomic operations used for reference-counting are annotated so that
- they can be understood by race detectors such as Helgrind, see
- [14]Data Race Hunting.
- * Most libstdc++ standard headers have been changed to no longer
- include the cstddef header as an implementation detail. Code that
- relied on that header being included as side-effect of including
- other standard headers will need to include cstddef explicitly.
-
- Fortran
-
- * On systems supporting the libquadmath library, GNU Fortran now also
- supports a quad-precision, kind=16 floating-point data type
- (REAL(16), COMPLEX(16)). As the data type is not fully supported in
- hardware, calculations might be one to two orders of magnitude
- slower than with the 4, 8 or 10 bytes floating-point data types.
- This change does not affect systems which support REAL(16) in
- hardware nor those which do not support libquadmath.
- * Much improved compile time for large array constructors.
- * In order to reduce execution time and memory consumption, use of
- temporary arrays in assignment expressions is avoided for many
- cases. The compiler now reverses loops in order to avoid generating
- a temporary array where possible.
- * Improved diagnostics, especially with -fwhole-file.
- * The -fwhole-file flag is now enabled by default. This improves code
- generation and diagnostics. It can be disabled using the deprecated
- -fno-whole-file flag.
- * Support the generation of Makefile dependencies via the [15]-M...
- flags of GCC; you may need to specify the -cpp option in addition.
- The dependencies take modules, Fortran's include, and CPP's
- #include into account. Note: Using -M for the module path is no
- longer supported, use -J instead.
- * The flag -Wconversion has been modified to only issue warnings
- where a conversion leads to information loss. This drastically
- reduces the number of warnings; -Wconversion is thus now enabled
- with -Wall. The flag -Wconversion-extra has been added and also
- warns about other conversions; -Wconversion-extra typically issues
- a huge number of warnings, most of which can be ignored.
- * A new command-line option -Wunused-dummy-argument warns about
- unused dummy arguments and is included in -Wall. Before,
- -Wunused-variable also warned about unused dummy arguments.
- * Fortran 2003 support has been extended:
- + Improved support for polymorphism between libraries and
- programs and for complicated inheritance patterns (cf.
- [16]object-oriented programming).
- + Experimental support of the ASSOCIATE construct.
- + In pointer assignments it is now possible to specify the lower
- bounds of the pointer and, for a rank-1 or a simply contiguous
- data-target, to remap the bounds.
- + Automatic (re)allocation: In intrinsic assignments to
- allocatable variables the left-hand side will be automatically
- allocated (if unallocated) or reallocated (if the shape or
- type parameter is different). To avoid the small performance
- penalty, you can use a(:) = ... instead of a = ... for arrays
- and character strings – or disable the feature using -std=f95
- or -fno-realloc-lhs.
- + Deferred type parameter: For scalar allocatable and pointer
- variables the character length can be deferred.
- + Namelist variables with allocatable and pointer attribute and
- nonconstant length type parameter are supported.
- * Fortran 2008 support has been extended:
- + Experimental [17]coarray support (for one image only, i.e.
- num_images() == 1); use the [18]-fcoarray=single flag to
- enable it.
- + The STOP and the new ERROR STOP statements now support all
- constant expressions.
- + Support for the CONTIGUOUS attribute.
- + Support for ALLOCATE with MOLD.
- + Support for the STORAGE_SIZE intrinsic inquiry function.
- + Support of the NORM2 and PARITY intrinsic functions.
- + The following bit intrinsics were added: POPCNT and POPPAR for
- counting the number of 1 bits and returning the parity; BGE,
- BGT, BLE, and BLT for bitwise comparisons; DSHIFTL and DSHIFTR
- for combined left and right shifts, MASKL and MASKR for simple
- left and right justified masks, MERGE_BITS for a bitwise merge
- using a mask, SHIFTA, SHIFTL and SHIFTR for shift operations,
- and the transformational bit intrinsics IALL, IANY and
- IPARITY.
- + Support of the EXECUTE_COMMAND_LINE intrinsic subroutine.
- + Support for the IMPURE attribute for procedures, which allows
- for ELEMENTAL procedures without the restrictions of PURE.
- + Null pointers (including NULL()) and not allocated variables
- can be used as actual argument to optional non-pointer,
- non-allocatable dummy arguments, denoting an absent argument.
- + Non-pointer variables with TARGET attribute can be used as
- actual argument to POINTER dummies with INTENT(IN)
- + Pointers including procedure pointers and those in a derived
- type (pointer components) can now be initialized by a target
- instead of only by NULL.
- + The EXIT statement (with construct-name) can now be used to
- leave not only the DO but also the ASSOCIATE, BLOCK, IF,
- SELECT CASE and SELECT TYPE constructs.
- + Internal procedures can now be used as actual argument.
- + The named constants INTEGER_KINDS, LOGICAL_KINDS, REAL_KINDS
- and CHARACTER_KINDS of the intrinsic module ISO_FORTRAN_ENV
- have been added; these arrays contain the supported kind
- values for the respective types.
- + The module procedures C_SIZEOF of the intrinsic module
- ISO_C_BINDINGS and COMPILER_VERSION and COMPILER_OPTIONS of
- ISO_FORTRAN_ENV have been implemented.
- + Minor changes: obsolescence diagnostics for ENTRY was added
- for -std=f2008; a line may start with a semicolon; for
- internal and module procedures END can be used instead of END
- SUBROUTINE and END FUNCTION; SELECTED_REAL_KIND now also takes
- a RADIX argument; intrinsic types are supported for
- TYPE(intrinsic-type-spec); multiple type-bound procedures can
- be declared in a single PROCEDURE statement; implied-shape
- arrays are supported for named constants (PARAMETER). The
- transformational, three argument versions of BESSEL_JN and
- BESSEL_YN were added – the elemental, two-argument version had
- been added in GCC 4.4; note that the transformational
- functions use a recurrence algorithm.
-
- Go
-
- Support for the [19]Go programming language has been added to GCC. It
- is not enabled by default when you build GCC; use the
- --enable-languages configure option to build it. The driver program for
- compiling Go code is gccgo.
-
- Go is currently known to work on GNU/Linux and RTEMS. Solaris support
- is in progress. It may or may not work on other platforms.
-
- Objective-C and Objective-C++
-
- * The -fobjc-exceptions flag is now required to enable Objective-C
- exception and synchronization syntax (introduced by the keywords
- @try, @catch, @finally and @synchronized).
- * A number of Objective-C 2.0 features and extensions are now
- supported by GCC. These features are enabled by default; you can
- disable them by using the new -fobjc-std=objc1 command-line option.
- * The Objective-C 2.0 dot-syntax is now supported. It is an
- alternative syntax for using getters and setters; object.count is
- automatically converted into [object count] or [object setCount:
- ...] depending on context; for example if (object.count > 0) is
- automatically compiled into the equivalent of if ([object count] >
- 0) while object.count = 0; is automatically compiled into the
- equivalent ot [object setCount: 0];. The dot-syntax can be used
- with instance and class objects and with any setters or getters, no
- matter if they are part of a declared property or not.
- * Objective-C 2.0 declared properties are now supported. They are
- declared using the new @property keyword, and are most commonly
- used in conjunction with the new Objective-C 2.0 dot-syntax. The
- nonatomic, readonly, readwrite, assign, retain, copy, setter and
- getter attributes are all supported. Marking declared properties
- with __attribute__ ((deprecated)) is supported too.
- * The Objective-C 2.0 @synthesize and @dynamic keywords are
- supported. @synthesize causes the compiler to automatically
- synthesize a declared property, while @dynamic is used to disable
- all warnings for a declared property for which no implementation is
- provided at compile time. Synthesizing declared properties requires
- runtime support in most useful cases; to be able to use it with the
- GNU runtime, appropriate helper functions have been added to the
- GNU Objective-C runtime ABI, and are implemented by the GNU
- Objective-C runtime library shipped with GCC.
- * The Objective-C 2.0 fast enumeration syntax is supported in
- Objective-C. This is currently not yet available in Objective-C++.
- Fast enumeration requires support in the runtime, and such support
- has been added to the GNU Objective-C runtime library (shipped with
- GCC).
- * The Objective-C 2.0 @optional keyword is supported. It allows you
- to mark methods or properties in a protocol as optional as opposed
- to required.
- * The Objective-C 2.0 @package keyword is supported. It has currently
- the same effect as the @public keyword.
- * Objective-C 2.0 method attributes are supported. Currently the
- supported attributes are deprecated, sentinel, noreturn and format.
- * Objective-C 2.0 method argument attributes are supported. The most
- widely used attribute is unused, to mark an argument as unused in
- the implementation.
- * Objective-C 2.0 class and protocol attributes are supported.
- Currently the only supported attribute is deprecated.
- * Objective-C 2.0 class extensions are supported. A class extension
- has the same syntax as a category declaration with no category
- name, and the methods and properties declared in it are added
- directly to the main class. It is mostly used as an alternative to
- a category to add methods to a class without advertising them in
- the public headers, with the advantage that for class extensions
- the compiler checks that all the privately declared methods are
- actually implemented.
- * As a result of these enhancements, GCC can now be used to build
- Objective-C and Objective-C++ software that uses Foundation and
- other important system frameworks with the NeXT runtime on Darwin 9
- and Darwin 10 (OSX 10.5 and 10.6).
- * Many bugs in the compiler have been fixed in this release; in
- particular, LTO can now be used when compiling Objective-C and
- Objective-C++ and the parser is much more robust in dealing with
- invalid code.
-
- Runtime Library (libobjc)
-
- * The GNU Objective-C runtime library now defines the macro
- __GNU_LIBOBJC__ (with a value that is increased at every release
- where there is any change to the API) in objc/objc.h, making it
- easy to determine if the GNU Objective-C runtime library is being
- used, and if so, which version. Previous versions of the GNU
- Objective-C runtime library (and other Objective-C runtime
- libraries such as the Apple one) do not define this macro.
- * A new Objective-C 2.0 API, almost identical to the one implemented
- by the Apple Objective-C runtime, has been implemented in the GNU
- Objective-C runtime library. The new API hides the internals of
- most runtime structures but provides a more extensive set of
- functions to operate on them. It is much easier, for example, to
- create or modify classes at runtime. The new API also makes it
- easier to port software from Apple to GNU as almost no changes
- should be required. The old API is still supported for backwards
- compatibility; including the old objc/objc-api.h header file
- automatically selects the old API, while including the new
- objc/runtime.h header file automatically selects the new API.
- Support for the old API is being phased out and upgrading the
- software to use the new API is strongly recommended. To check for
- the availability of the new API, the __GNU_LIBOBJC__ macro can be
- used as older versions of the GNU Objective-C runtime library,
- which do not support the new API, do not define such a macro.
- * Runtime support for @synchronized has been added.
- * Runtime support for Objective-C 2.0 synthesized property accessors
- has been added.
- * Runtime support for Objective-C 2.0 fast enumeration has been
- added.
-
-New Targets and Target Specific Improvements
-
- ARM
-
- * GCC now supports the Cortex-M4 processor implementing the v7-em
- version of the architecture using the option -mcpu=cortex-m4.
- * Scheduling descriptions for the Cortex-M4, the Neon and the
- floating point units of the Cortex-A9 and a pipeline description
- for the Cortex-A5 have been added.
- * Synchronization primitives such as __sync_fetch_and_add and friends
- are now inlined for supported architectures rather than calling
- into a kernel helper function.
- * SSA loop prefetching is enabled by default for the Cortex-A9 at
- -O3.
- * Several improvements were committed to improve code generation for
- the ARM architecture including a rewritten implementation for load
- and store multiples.
- * Several enhancements were committed to improve SIMD code generation
- for NEON by adding support for widening instructions, misaligned
- loads and stores, vector conditionals and support for 64 bit
- arithmetic.
- * Support was added for the Faraday cores fa526, fa606te, fa626te,
- fmp626te, fmp626 and fa726te and can be used with the respective
- names as parameters to the -mcpu= option.
- * Basic support was added for Cortex-A15 and is available through
- -mcpu=cortex-a15.
- * GCC for AAPCS configurations now more closely adheres to the AAPCS
- specification by enabling -fstrict-volatile-bitfields by default.
-
- IA-32/x86-64
-
- * The new -fsplit-stack option permits programs to use a
- discontiguous stack. This is useful for threaded programs, in that
- it is no longer necessary to specify the maximum stack size when
- creating a thread. This feature is currently only implemented for
- 32-bit and 64-bit x86 GNU/Linux targets.
- * Support for emitting profiler counter calls before function
- prologues. This is enabled via a new command-line option -mfentry.
- * Optimization for the Intel Core 2 processors is now available
- through the -march=core2 and -mtune=core2 options.
- * Support for Intel Core i3/i5/i7 processors is now available through
- the -march=corei7 and -mtune=corei7 options.
- * Support for Intel Core i3/i5/i7 processors with AVX is now
- available through the -march=corei7-avx and -mtune=corei7-avx
- options.
- * Support for AMD Bobcat (family 14) processors is now available
- through the -march=btver1 and -mtune=btver1 options.
- * Support for AMD Bulldozer (family 15) processors is now available
- through the -march=bdver1 and -mtune=bdver1 options.
- * The default setting (when not optimizing for size) for 32-bit
- GNU/Linux and Darwin x86 targets has been changed to
- -fomit-frame-pointer. The default can be reverted to
- -fno-omit-frame-pointer by configuring GCC with the
- --enable-frame-pointer configure option.
- * Darwin, FreeBSD, Solaris 2, MinGW and Cygwin now all support
- __float128 on 32-bit and 64-bit x86 targets.
- * AVX floating-point arithmetic can now be enabled by default at
- configure time with the new --with-fpmath=avx option.
- * The SSA loop prefetching pass is enabled when using -O3 when
- optimizing for CPUs where prefetching is beneficial (AMD CPUs newer
- than K6).
- * Support for TBM (Trailing Bit Manipulation) built-in functions and
- code generation is available via -mtbm.
- * Support for AMD's BMI (Bit Manipulation) built-in functions and
- code generation is available via -mbmi.
-
- MicroBlaze
-
- * Support has been added for the Xilinx MicroBlaze softcore processor
- (microblaze-elf) embedded target. This configurable processor is
- supported on several Xilinx Spartan and Virtex FPGAs.
-
- MIPS
-
- * GCC now supports the Loongson 3A processor. Its canonical -march=
- and -mtune= name is loongson3a.
-
- MN10300 / AM33
-
- * The inline assembly register constraint "A" has been renamed "c".
- This constraint is used to select a floating-point register that
- can be used as the destination of a multiply-accumulate
- instruction.
- * New inline assembly register constraints "A" and "D" have been
- added. These constraint letters resolve to all general registers
- when compiling for AM33, and resolve to address registers only or
- data registers only when compiling for MN10300.
- * The MDR register is represented in the compiler. One can access the
- register via the "z" constraint in inline assembly. It can be
- marked as clobbered or used as a local register variable via the
- "mdr" name. The compiler uses the RETF instruction if the function
- does not modify the MDR register, so it is important that inline
- assembly properly annotate any usage of the register.
-
- PowerPC/PowerPC64
-
- * GCC now supports the Applied Micro Titan processor with
- -mcpu=titan.
- * The -mrecip option has been added, which indicates whether the
- reciprocal and reciprocal square root instructions should be used.
- * The -mveclibabi=mass option can be used to enable the compiler to
- autovectorize mathematical functions using the Mathematical
- Acceleration Subsystem library.
- * The -msingle-pic-base option has been added, which instructs the
- compiler to avoid loading the PIC base register in function
- prologues. The PIC base register must be initialized by the runtime
- system.
- * The -mblock-move-inline-limit option has been added, which enables
- the user to control the maximum size of inlined memcpy calls and
- similar.
- * PowerPC64 GNU/Linux support for applications requiring a large TOC
- section has been improved. A new command-line option,
- -mcmodel=MODEL, controls this feature; valid values for MODEL are
- small, medium, or large.
- * The Altivec builtin functions vec_ld and vec_st have been modified
- to generate the Altivec memory instructions LVX and STVX, even if
- the -mvsx option is used. In the initial GCC 4.5 release, these
- builtin functions were changed to generate VSX memory reference
- instructions instead of Altivec memory instructions, but there are
- differences between the two instructions. If the VSX instruction
- set is available, you can now use the new builtin functions
- vec_vsx_ld and vec_vsx_st which always generates the VSX memory
- instructions.
- * The GCC compiler on AIX now defaults to a process layout with a
- larger data space allowing larger programs to be compiled.
- * The GCC long double type on AIX 6.1 and above has reverted to 64
- bit double precision, matching the AIX XL compiler default, because
- of missing C99 symbols required by the GCC runtime.
- * The default processor scheduling model and tuning for PowerPC64
- GNU/Linux and for AIX 6.1 and above now is POWER7.
- * Starting with GCC 4.6.1, vectors of type vector long long or vector
- long are passed and returned in the same method as other vectors
- with the VSX instruction set. Previously the GCC compiler did not
- adhere to the ABI for 128-bit vectors with 64-bit integer base
- types (PR 48857). This is also fixed in the GCC 4.5.4 release.
-
- S/390, zSeries and System z9/z10, IBM zEnterprise z196
-
- * Support for the zEnterprise z196 processor has been added. When
- using the -march=z196 option, the compiler will generate code
- making use of the following instruction facilities:
- + Conditional load/store
- + Distinct-operands
- + Floating-point-extension
- + Interlocked-access
- + Population-count
- The -mtune=z196 option avoids the compare and branch instructions
- as well as the load address instruction with an index register as
- much as possible and performs instruction scheduling appropriate
- for the new out-of-order pipeline architecture.
- * When using the -m31 -mzarch options the generated code still
- conforms to the 32-bit ABI but uses the general purpose registers
- as 64-bit registers internally. This requires a Linux kernel saving
- the whole 64-bit registers when doing a context switch. Kernels
- providing that feature indicate that by the 'highgprs' string in
- /proc/cpuinfo.
- * The SSA loop prefetching pass is enabled when using -O3.
-
- SPARC
-
- * GCC now supports the LEON series of SPARC V8 processors. The code
- generated by the compiler can either be tuned to it by means of the
- --with-tune=leon configure option and -mtune=leon compilation
- option, or the compiler can be built for the sparc-leon-{elf,linux}
- and sparc-leon3-{elf,linux} targets directly.
- * GCC has stopped sign/zero-extending parameter registers in the
- callee for functions taking parameters with sub-word size in 32-bit
- mode, since this is redundant with the specification of the ABI.
- GCC has never done so in 64-bit mode since this is also redundant.
- * The command line option -mfix-at697f has been added to enable the
- documented workaround for the single erratum of the Atmel AT697F
- processor.
-
-Operating Systems
-
- Android
-
- * GCC now supports the Bionic C library and provides a convenient way
- of building native libraries and applications for the Android
- platform. Refer to the documentation of the -mandroid and -mbionic
- options for details on building native code. At the moment, Android
- support is enabled only for ARM.
-
- Darwin/Mac OS X
-
- * General
- + Initial support for CFString types has been added.
- This allows GCC to build projects including the system Core
- Foundation frameworks. The GCC Objective-C family supports
- CFString "toll-free bridged" as per the Mac OS X system tools.
- CFString is also recognized in the context of format
- attributes and arguments (see the documentation for format
- attributes for limitations). At present, 8-bit character types
- are supported.
- + Object file size reduction.
- The Darwin zeroed memory allocators have been re-written to
- make more use of .zerofill sections. For non-debug code, this
- can reduce object file size significantly.
- + Objective-C family 64-bit support (NeXT ABI 2).
- Initial support has been added to support 64-bit Objective-C
- code using the Darwin/OS X native (NeXT) runtime. ABI version
- 2 will be selected automatically when 64-bit code is built.
- + Objective-C family 32-bit ABI 1.
- For 32-bit code ABI 1 is also now also allowed. At present it
- must be selected manually using -fobjc-abi-version=1 where
- applicable - i.e. on Darwin 9/10 (OS X 10.5/10.6).
- * x86 Architecture
- + The -mdynamic-no-pic option has been enabled.
- Code supporting -mdynamic-no-pic optimization has been added
- and is applicable to -m32 builds. The compiler bootstrap uses
- the option where appropriate.
- + The default value for -mtune= has been changed.
- Since Darwin systems are primarily Xeon, Core-2 or similar the
- default tuning has been changed to -mtune=core2.
- + Enable 128-bit long double (__float128) support on Darwin.
- * PPC Architecture
- + Darwin64 ABI.
- Several significant bugs have been fixed, such that GCC now
- produces code compatible with the Darwin64 PowerPC ABI.
- + libffi and boehm-gc.
- The Darwin ports of the libffi and boehm-gc libraries have
- been upgraded to include a Darwin64 implementation. This means
- that powerpc*-*-darwin9 platforms may now, for example, build
- Java applications with -m64 enabled.
- + Plug-in support has been enabled.
- + The -fsection-anchors option is now available although,
- presently, not heavily tested.
-
- Solaris 2
-
- New Features
-
- * Support symbol versioning with the Sun linker.
- * Allow libstdc++ to leverage full ISO C99 support on Solaris 10+.
- * Support thread-local storage (TLS) with the Sun assembler on
- Solaris 2/x86.
- * Support TLS on Solaris 8/9 if prerequisites are met.
- * Support COMDAT group with the GNU assembler and recent Sun linker.
- * Support the Sun assembler visibility syntax.
- * Default Solaris 2/x86 to -march=pentium4 (Solaris 10+) resp.
- -march=pentiumpro (Solaris 8/9).
- * Don't use SSE on Solaris 8/9 x86 by default.
- * Enable 128-bit long double (__float128) support on Solaris 2/x86.
-
- ABI Change
-
- * Change the ABI for returning 8-byte vectors like __m64 in MMX
- registers on Solaris 10+/x86 to match the Sun Studio 12.1+
- compilers. This is an incompatible change. If you use such types,
- you must either recompile all your code with the new compiler or
- use the new -mvect8-ret-in-mem option to remain compatible with
- previous versions of GCC and Sun Studio.
-
- Windows x86/x86_64
-
- * Initial support for decimal floating point.
- * Support for the __thiscall calling-convention.
- * Support for hot-patchable function prologues via the
- ms_hook_prologue attribute for x86_64 in addition to 32-bit x86.
- * Improvements of stack-probing and stack-allocation mechanisms.
- * Support of push/pop-macro pragma as preprocessor command.
- With #pragma push_macro("macro-name") the current definition of
- macro-name is saved and can be restored with #pragma
- pop_macro("macro-name") to its saved definition.
- * Enable 128-bit long double (__float128) support on MinGW and
- Cygwin.
-
-Other significant improvements
-
- Installation changes
-
- * An install-strip make target is provided that installs stripped
- executables, and may install libraries with unneeded or debugging
- sections stripped.
- * On Power7 systems, there is a potential problem if you build the
- GCC compiler with a host compiler using options that enable the VSX
- instruction set generation. If the host compiler has been patched
- so that the vec_ld and vec_st builtin functions generate Altivec
- memory instructions instead of VSX memory instructions, then you
- should be able to build the compiler with VSX instruction
- generation.
-
-Changes for GCC Developers
-
- Note: these changes concern developers that develop GCC itself or
- software that integrates with GCC, such as plugins, and not the general
- GCC users.
- * The gengtype utility, which previously was internal to the GCC
- build process, has been enchanced to provide GC root information
- for plugins as necessary.
- * The old GC allocation interface of ggc_alloc and friends was
- replaced with a type-safe alternative.
-
-GCC 4.6.1
-
- This is the [20]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.6.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.6.2
-
- This is the [21]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.6.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.6.3
-
- This is the [22]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.6.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.6.4
-
- This is the [23]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.6.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [24]GCC manuals. If that fails, the
- [25]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [26]gcc at gcc.gnu.org. All of [27]our lists have public
- archives.
-
- Copyright (C) [28]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [29]maintained by the GCC team. Last modified
- 2014-12-06[30].
-
-References
-
- 1. http://sourceware.org/bugzilla/show_bug.cgi?id=10401
- 2. http://gcc.gnu.org/gcc-4.5/changes.html
- 3. http://gcc.gnu.org/gcc-4.5/changes.html#obsoleted
- 4. http://gcc.gnu.org/gcc-4.6/porting_to.html
- 5. http://gcc.gnu.org/projects/lto/whopr.pdf
- 6. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#Warning-Options
- 7. http://gcc.gnu.org/gcc-4.6/cxx0x_status.html
- 8. https://gcc.gnu.org/PR43145
- 9. https://gcc.gnu.org/PR43680
- 10. https://gcc.gnu.org/PR33558
- 11. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#253
- 12. https://gcc.gnu.org/onlinedocs/gcc-4.6.4/libstdc++/manual/manual/status.html#status.iso.200x
- 13. https://gcc.gnu.org/onlinedocs/libstdc++/manual/debug_mode.html
- 14. https://gcc.gnu.org/onlinedocs/libstdc++/manual/debug.html#debug.races
- 15. https://gcc.gnu.org/onlinedocs/gcc/Preprocessor-Options.html
- 16. https://gcc.gnu.org/wiki/OOP
- 17. https://gcc.gnu.org/wiki/Coarray
- 18. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfcoarray_007d-233
- 19. http://golang.org/
- 20. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.1
- 21. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.2
- 22. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.3
- 23. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.4
- 24. https://gcc.gnu.org/onlinedocs/
- 25. mailto:gcc-help at gcc.gnu.org
- 26. mailto:gcc at gcc.gnu.org
- 27. https://gcc.gnu.org/lists.html
- 28. http://www.fsf.org/
- 29. https://gcc.gnu.org/about.html
- 30. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.5/index.html
- GCC 4.5 Release Series
-
- Jul 2, 2012
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.5.4.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.5.3 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.5.4
- Jul 2, 2012 ([2]changes)
-
- GCC 4.5.3
- Apr 28, 2011 ([3]changes)
-
- GCC 4.5.2
- Dec 16, 2010 ([4]changes)
-
- GCC 4.5.1
- Jul 31, 2010 ([5]changes)
-
- GCC 4.5.0
- April 14, 2010 ([6]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [7]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [8]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [9]GCC project
- web site or contact the [10]GCC development mailing list.
-
- To obtain GCC please use [11]our mirror sites or [12]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [13]GCC manuals. If that fails, the
- [14]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [15]gcc at gcc.gnu.org. All of [16]our lists have public
- archives.
-
- Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [18]maintained by the GCC team. Last modified
- 2014-06-28[19].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.5/changes.html
- 3. http://gcc.gnu.org/gcc-4.5/changes.html
- 4. http://gcc.gnu.org/gcc-4.5/changes.html
- 5. http://gcc.gnu.org/gcc-4.5/changes.html
- 6. http://gcc.gnu.org/gcc-4.5/changes.html
- 7. http://gcc.gnu.org/gcc-4.5/buildstat.html
- 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 9. http://gcc.gnu.org/index.html
- 10. mailto:gcc at gcc.gnu.org
- 11. http://gcc.gnu.org/mirrors.html
- 12. http://gcc.gnu.org/svn.html
- 13. https://gcc.gnu.org/onlinedocs/
- 14. mailto:gcc-help at gcc.gnu.org
- 15. mailto:gcc at gcc.gnu.org
- 16. https://gcc.gnu.org/lists.html
- 17. http://www.fsf.org/
- 18. https://gcc.gnu.org/about.html
- 19. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.5/changes.html
- GCC 4.5 Release Series
- Changes, New Features, and Fixes
-
-Caveats
-
- * GCC now requires the [1]MPC library in order to build. See the
- [2]prerequisites page for version requirements.
- * Support for a number of older systems and recently unmaintained or
- untested target ports of GCC has been declared obsolete in GCC 4.5.
- Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
- The following ports for individual systems on particular
- architectures have been obsoleted:
- + IRIX releases before 6.5 (mips-sgi-irix5*,
- mips-sgi-irix6.[0-4])
- + Solaris 7 (*-*-solaris2.7)
- + Tru64 UNIX releases before V5.1 (alpha*-dec-osf4*,
- alpha-dec-osf5.0*)
- + Details for the IRIX, Solaris 7, and Tru64 UNIX obsoletions
- can be found in the [3]announcement.
- Support for the classic POWER architecture implemented in the
- original RIOS and RIOS2 processors of the old IBM RS/6000 product
- line has been obsoleted in the rs6000 port. This does not affect
- the new generation Power and PowerPC architectures.
- * Support has been removed for all the [4]configurations obsoleted in
- GCC 4.4.
- * Support has been removed for the protoize and unprotoize utilities,
- obsoleted in GCC 4.4.
- * Support has been removed for tuning for Itanium1 (Merced) variants.
- Note that code tuned for Itanium2 should also run correctly on
- Itanium1.
- * GCC now generates unwind info also for epilogues. DWARF debuginfo
- generated by GCC now uses more features of DWARF3 than before, and
- also some DWARF4 features. GDB older than 7.0 is not able to handle
- either of these, so to debug GCC 4.5 generated binaries or
- libraries GDB 7.0 or later is needed. You can disable use of DWARF4
- features with the -gdwarf-3 -gstrict-dwarf options, or use
- -gdwarf-2 -gstrict-dwarf to restrict GCC to just DWARF2, but
- epilogue unwind info is emitted unconditionally whenever unwind
- info is emitted.
- * On x86 targets, code containing floating-point calculations may run
- significantly slower when compiled with GCC 4.5 in strict C99
- conformance mode than they did with earlier GCC versions. This is
- due to stricter standard conformance of the compiler and can be
- avoided by using the option -fexcess-precision=fast; also see
- [5]below.
- * The function attribute noinline no longer prevents GCC from cloning
- the function. A new attribute noclone has been introduced for this
- purpose. Cloning a function means that it is duplicated and the new
- copy is specialized for certain contexts (for example when a
- parameter is a known constant).
-
-General Optimizer Improvements
-
- * The -save-temps now takes an optional argument. The -save-temps and
- -save-temps=cwd switches write the temporary files in the current
- working directory based on the original source file. The
- -save-temps=obj switch will write files into the directory
- specified with the -o option, and the intermediate filenames are
- based on the output file. This will allow the user to get the
- compiler intermediate files when doing parallel builds without two
- builds of the same filename located in different directories from
- interfering with each other.
- * Debugging dumps are now created in the same directory as the object
- file rather than in the current working directory. This allows the
- user to get debugging dumps when doing parallel builds without two
- builds of the same filename interfering with each other.
- * GCC has been integrated with the [6]MPC library. This allows GCC to
- evaluate complex arithmetic at compile time [7]more accurately. It
- also allows GCC to evaluate calls to complex built-in math
- functions having constant arguments and replace them at compile
- time with their mathematically equivalent results. In doing so, GCC
- can generate correct results regardless of the math library
- implementation or floating point precision of the host platform.
- This also allows GCC to generate identical results regardless of
- whether one compiles in native or cross-compile configurations to a
- particular target. The following built-in functions take advantage
- of this new capability: cacos, cacosh, casin, casinh, catan,
- catanh, ccos, ccosh, cexp, clog, cpow, csin, csinh, csqrt, ctan,
- and ctanh. The float and long double variants of these functions
- (e.g. csinf and csinl) are also handled.
- * A new link-time optimizer has been added ([8]-flto). When this
- option is used, GCC generates a bytecode representation of each
- input file and writes it to specially-named sections in each object
- file. When the object files are linked together, all the function
- bodies are read from these named sections and instantiated as if
- they had been part of the same translation unit. This enables
- interprocedural optimizations to work across different files (and
- even different languages), potentially improving the performance of
- the generated code. To use the link-timer optimizer, -flto needs to
- be specified at compile time and during the final link. If the
- program does not require any symbols to be exported, it is possible
- to combine -flto and the experimental [9]-fwhopr with
- [10]-fwhole-program to allow the interprocedural optimizers to use
- more aggressive assumptions.
- * The automatic parallelization pass was enhanced to support
- parallelization of outer loops.
- * Automatic parallelization can be enabled as part of Graphite. In
- addition to -ftree-parallelize-loops=, specify
- -floop-parallelize-all to enable the Graphite-based optimization.
- * The infrastructure for optimizing based on [11]restrict qualified
- pointers has been rewritten and should result in code generation
- improvements. Optimizations based on restrict qualified pointers
- are now also available when using -fno-strict-aliasing.
- * There is a new optimization pass that attempts to change prototype
- of functions to avoid unused parameters, pass only relevant parts
- of structures and turn arguments passed by reference to arguments
- passed by value when possible. It is enabled by -O2 and above as
- well as -Os and can be manually invoked using the new command-line
- switch -fipa-sra.
- * GCC now optimize exception handling code. In particular cleanup
- regions that are proved to not have any effect are optimized out.
-
-New Languages and Language specific improvements
-
- All languages
-
- * The -fshow-column option is now on by default. This means error
- messages now have a column associated with them.
-
- Ada
-
- * Compilation of programs heavily using discriminated record types
- with variant parts has been sped up and generates more compact
- code.
- * Stack checking now works reasonably well on most plaforms. In some
- specific cases, stack overflows may still fail to be detected, but
- a compile-time warning will be issued for these cases.
-
- C family
-
- * If a header named in a #include directive is not found, the
- compiler exits immediately. This avoids a cascade of errors arising
- from declarations expected to be found in that header being
- missing.
- * A new built-in function __builtin_unreachable() has been added that
- tells the compiler that control will never reach that point. It may
- be used after asm statements that terminate by transferring control
- elsewhere, and in other places that are known to be unreachable.
- * The -Wlogical-op option now warns for logical expressions such as
- (c == 1 && c == 2) and (c != 1 || c != 2), which are likely to be
- mistakes. This option is disabled by default.
- * An asm goto feature has been added to allow asm statements that
- jump to C labels.
- * C++0x raw strings are supported for C++ and for C with -std=gnu99.
- * The deprecated attribute now takes an optional string argument, for
- example, __attribute__((deprecated("text string"))), that will be
- printed together with the deprecation warning.
-
- C
-
- * The -Wenum-compare option, which warns when comparing values of
- different enum types, now works for C. It formerly only worked for
- C++. This warning is enabled by -Wall. It may be avoided by using a
- type cast.
- * The -Wcast-qual option now warns about casts which are unsafe in
- that they permit const-correctness to be violated without further
- warnings. Specifically, it warns about cases where a qualifier is
- added when all the lower types are not const. For example, it warns
- about a cast from char ** to const char **.
- * The -Wc++-compat option is significantly improved. It issues new
- warnings for:
- + Using C++ reserved operator names as identifiers.
- + Conversions to enum types without explicit casts.
- + Using va_arg with an enum type.
- + Using different enum types in the two branches of ?:.
- + Using ++ or -- on a variable of enum type.
- + Using the same name as both a struct, union or enum tag and a
- typedef, unless the typedef refers to the tagged type itself.
- + Using a struct, union, or enum which is defined within another
- struct or union.
- + A struct field defined using a typedef if there is a field in
- the struct, or an enclosing struct, whose name is the typedef
- name.
- + Duplicate definitions at file scope.
- + Uninitialized const variables.
- + A global variable with an anonymous struct, union, or enum
- type.
- + Using a string constant to initialize a char array whose size
- is the length of the string.
- * The new -Wjump-misses-init option warns about cases where a goto or
- switch skips the initialization of a variable. This sort of branch
- is an error in C++ but not in C. This warning is enabled by
- -Wc++-compat.
- * GCC now ensures that a C99-conforming <stdint.h> is present on most
- targets, and uses information about the types in this header to
- implement the Fortran bindings to those types. GCC does not ensure
- the presence of such a header, and does not implement the Fortran
- bindings, on the following targets: NetBSD, VxWorks, VMS,
- SymbianOS, WinCE, LynxOS, Netware, QNX, Interix, TPF.
- * GCC now implements C90- and C99-conforming rules for constant
- expressions. This may cause warnings or errors for some code using
- expressions that can be folded to a constant but are not constant
- expressions as defined by ISO C.
- * All known target-independent C90 and C90 Amendment 1 conformance
- bugs, and all known target-independent C99 conformance bugs not
- related to floating point or extended identifiers, have been fixed.
- * The C decimal floating point support now includes support for the
- FLOAT_CONST_DECIMAL64 pragma.
- * The named address space feature from ISO/IEC TR 18037 is now
- supported. This is currently only implemented for the SPU
- processor.
-
- C++
-
- * Improved [12]experimental support for the upcoming C++0x ISO C++
- standard, including support for raw strings, lambda expressions and
- explicit type conversion operators.
- * When printing the name of a class template specialization, G++ will
- now omit any template arguments which come from default template
- arguments. This behavior (and the pretty-printing of function
- template specializations as template signature and arguments) can
- be disabled with the -fno-pretty-templates option.
- * Access control is now applied to typedef names used in a template,
- which may cause G++ to reject some ill-formed code that was
- accepted by earlier releases. The -fno-access-control option can be
- used as a temporary workaround until the code is corrected.
- * Compilation time for code that uses templates should now scale
- linearly with the number of instantiations rather than
- quadratically, as template instantiations are now looked up using
- hash tables.
- * Declarations of functions that look like builtin declarations of
- library functions are only considered to be redeclarations if they
- are declared with extern "C". This may cause problems with code
- that omits extern "C" on hand-written declarations of C library
- functions such as abort or memcpy. Such code is ill-formed, but was
- accepted by earlier releases.
- * Diagnostics that used to complain about passing non-POD types to
- ... or jumping past the declaration of a non-POD variable now check
- for triviality rather than PODness, as per C++0x.
- * In C++0x mode local and anonymous classes are now allowed as
- template arguments, and in declarations of variables and functions
- with linkage, so long as any such declaration that is used is also
- defined ([13]DR 757).
- * Labels may now have attributes, as has been permitted for a while
- in C. This is only permitted when the label definition and the
- attribute specifier is followed by a semicolon—i.e., the label
- applies to an empty statement. The only useful attribute for a
- label is unused.
- * G++ now implements [14]DR 176. Previously G++ did not support using
- the injected-class-name of a template base class as a type name,
- and lookup of the name found the declaration of the template in the
- enclosing scope. Now lookup of the name finds the
- injected-class-name, which can be used either as a type or as a
- template, depending on whether or not the name is followed by a
- template argument list. As a result of this change, some code that
- was previously accepted may be ill-formed because
- 1. The injected-class-name is not accessible because it's from a
- private base, or
- 2. The injected-class-name cannot be used as an argument for a
- template template parameter.
- In either of these cases, the code can be fixed by adding a
- nested-name-specifier to explicitly name the template. The first
- can be worked around with -fno-access-control; the second is only
- rejected with -pedantic.
- * A new standard mangling for SIMD vector types has been added, to
- avoid name clashes on systems with vectors of varying length. By
- default the compiler still uses the old mangling, but emits aliases
- with the new mangling on targets that support strong aliases. Users
- can switch over entirely to the new mangling with -fabi-version=4
- or -fabi-version=0. -Wabi will now warn about code that uses the
- old mangling.
- * The command-line option -ftemplate-depth-N is now written as
- -ftemplate-depth=N and the old form is deprecated.
- * Conversions between NULL and non-pointer types are now warned by
- default. The new option -Wno-conversion-null disables these
- warnings. Previously these warnings were only available when using
- -Wconversion explicitly.
-
- Runtime Library (libstdc++)
-
- * Improved experimental support for the upcoming ISO C++ standard,
- C++0x, including:
- + Support for <future>, <functional>, and <random>.
- + Existing facilities now exploit explicit operators and the
- newly implemented core C++0x features.
- + The header <cstdatomic> has been renamed to <atomic>.
- * An experimental [15]profile mode has been added. This is an
- implementation of many C++ standard library constructs with an
- additional analysis layer that gives performance improvement advice
- based on recognition of suboptimal usage patterns. For example,
-#include <vector>
-int main()
-{
- std::vector<int> v;
- for (int k = 0; k < 1024; ++k)
- v.insert(v.begin(), k);
-}
-
- When instrumented via the profile mode, can return suggestions
- about the initial size and choice of the container used as follows:
-vector-to-list: improvement = 5: call stack = 0x804842c ...
- : advice = change std::vector to std::list
-vector-size: improvement = 3: call stack = 0x804842c ...
- : advice = change initial container size from 0 to 1024
-
- These constructs can be substituted for the normal libstdc++
- constructs on a piecemeal basis, or all existing components can be
- transformed via the -D_GLIBCXX_PROFILE macro.
- * [16]Support for decimal floating-point arithmetic (aka ISO C++ TR
- 24733) has been added. This support is in header file
- <decimal/decimal>, uses namespace std::decimal, and includes
- classes decimal32, decimal64, and decimal128.
- * Sources have been audited for application of function attributes
- nothrow, const, pure, and noreturn.
- * Python pretty-printers have been added for many standard library
- components that simplify the internal representation and present a
- more intuitive view of components when used with
- appropriately-advanced versions of GDB. For more information,
- please consult the more [17]detailed description.
- * The default behavior for comparing typeinfo names has changed, so
- in <typeinfo>, __GXX_MERGED_TYPEINFO_NAMES now defaults to zero.
- * The new -static-libstdc++ option directs g++ to link the C++
- library statically, even if the default would normally be to link
- it dynamically.
-
- Fortran
-
- * The COMMON default padding has been changed – instead of adding the
- padding before a variable it is now added afterwards, which
- increases the compatibility with other vendors and helps to obtain
- the correct output in some cases. Cf. also the -falign-commons
- option ([18]added in 4.4).
- * The -finit-real= option now also supports the value snan for
- signalling not-a-number; to be effective, one additionally needs to
- enable trapping (e.g. via -ffpe-trap=). Note: Compile-time
- optimizations can turn a signalling NaN into a quiet one.
- * The new option -fcheck= has been added with the options bounds,
- array-temps, do, pointer, and recursive. The bounds and array-temps
- options are equivalent to -fbounds-check and
- -fcheck-array-temporaries. The do option checks for invalid
- modification of loop iteration variables, and the recursive option
- tests for recursive calls to subroutines/functions which are not
- marked as recursive. With pointer pointer association checks in
- calls are performed; however, neither undefined pointers nor
- pointers in expressions are handled. Using -fcheck=all enables all
- these run-time checks.
- * The run-time checking -fcheck=bounds now warns about invalid string
- lengths of character dummy arguments. Additionally, more
- compile-time checks have been added.
- * The new option [19]-fno-protect-parens has been added; if set, the
- compiler may reorder REAL and COMPLEX expressions without regard to
- parentheses.
- * GNU Fortran no longer links against libgfortranbegin. As before,
- MAIN__ (assembler symbol name) is the actual Fortran main program,
- which is invoked by the main function. However, main is now
- generated and put in the same object file as MAIN__. For the time
- being, libgfortranbegin still exists for backward compatibility.
- For details see the new [20]Mixed-Language Programming chapter in
- the manual.
- * The I/O library was restructured for performance and cleaner code.
- * Array assignments and WHERE are now run in parallel when OpenMP's
- WORKSHARE is used.
- * The experimental option -fwhole-file was added. The option allows
- whole-file checking of procedure arguments and allows for better
- optimizations. It can also be used with -fwhole-program, which is
- now also supported in gfortran.
- * More Fortran 2003 and Fortran 2008 mathematical functions can now
- be used as initialization expressions.
- * Some extended attributes such as STDCALL are now supported via the
- [21]GCC$ compiler directive.
- * For Fortran 77 compatibility: If -fno-sign-zero is used, the SIGN
- intrinsic behaves now as if zero were always positive.
- * For legacy compatibiliy: On Cygwin and MinGW, the special files
- CONOUT$ and CONIN$ (and CONERR$ which maps to CONOUT$) are now
- supported.
- * Fortran 2003 support has been extended:
- + Procedure-pointer function results and procedure-pointer
- components (including PASS),
- + allocatable scalars (experimental),
- + DEFERRED type-bound procedures,
- + the ERRMSG= argument of the ALLOCATE and DEALLOCATE statements
- have been implemented.
- + The ALLOCATE statement supports type-specs and the SOURCE=
- argument.
- + OPERATOR(*) and ASSIGNMENT(=) are now allowed as GENERIC
- type-bound procedure (i.e. as type-bound operators).
- + Rounding (ROUND=, RZ, ...) for output is now supported.
- + The INT_FAST{8,16,32,64,128}_T kind type parameters of the
- intrinsic module ISO_C_BINDING are now supported, except for
- the targets listed above as ones where GCC does not have
- <stdint.h> type information.
- + Extensible derived types with type-bound procedure or
- procedure pointer with PASS attribute now have to use CLASS in
- line with the Fortran 2003 standard; the workaround to use
- TYPE is no longer supported.
- + [22]Experimental, incomplete support for polymorphism,
- including CLASS, SELECT TYPE and dynamic dispatch of
- type-bound procedure calls. Some features do not work yet such
- as unlimited polymorphism (CLASS(*)).
- * Fortran 2008 support has been extended:
- + The OPEN statement now supports the NEWUNIT= option, which
- returns a unique file unit, thus preventing inadvertent use of
- the same unit in different parts of the program.
- + Support for unlimited format items has been added.
- + The INT{8,16,32} and REAL{32,64,128} kind type parameters of
- the intrinsic module ISO_FORTRAN_ENV are now supported.
- + Using complex arguments with TAN, SINH, COSH, TANH, ASIN,
- ACOS, and ATAN is now possible; the functions ASINH, ACOSH,
- and ATANH have been added (for real and complex arguments) and
- ATAN(Y,X) is now an alias for ATAN2(Y,X).
- + The BLOCK construct has been implemented.
-
-New Targets and Target Specific Improvements
-
- AIX
-
- * Full cross-toolchain support now available with GNU Binutils
-
- ARM
-
- * GCC now supports the Cortex-M0 and Cortex-A5 processors.
- * GCC now supports the ARM v7E-M architecture.
- * GCC now supports VFPv4-based FPUs and FPUs with
- single-precision-only VFP.
- * GCC has many improvements to optimization for other ARM processors,
- including scheduling support for the integer pipeline on Cortex-A9.
- * GCC now supports the IEEE 754-2008 half-precision floating-point
- type, and a variant ARM-specific half-precision type. This type is
- specified using __fp16, with the layout determined by
- -mfp16-format. With appropriate -mfpu options, the Cortex-A9 and
- VFPv4 half-precision instructions will be used.
- * GCC now supports the variant of AAPCS that uses VFP registers for
- parameter passing and return values.
-
- AVR
-
- * The -mno-tablejump option has been removed because it has the same
- effect as the -fno-jump-tables option.
- * Added support for these new AVR devices:
- + ATmega8U2
- + ATmega16U2
- + ATmega32U2
-
- IA-32/x86-64
-
- * GCC now will set the default for -march= based on the configure
- target.
- * GCC now supports handling floating-point excess precision arising
- from use of the x87 floating-point unit in a way that conforms to
- ISO C99. This is enabled with -fexcess-precision=standard and with
- standards conformance options such as -std=c99, and may be disabled
- using -fexcess-precision=fast.
- * Support for the Intel Atom processor is now available through the
- -march=atom and -mtune=atom options.
- * A new -mcrc32 option is now available to enable crc32 intrinsics.
- * A new -mmovbe option is now available to enable GCC to use the
- movbe instruction to implement __builtin_bswap32 and
- __builtin_bswap64.
- * SSE math now can be enabled by default at configure time with the
- new --with-fpmath=sse option.
- * There is a new intrinsic header file, <x86intrin.h>. It should be
- included before using any IA-32/x86-64 intrinsics.
- * Support for the XOP, FMA4, and LWP instruction sets for the AMD
- Orochi processors are now available with the -mxop, -mfma4, and
- -mlwp options.
- * The -mabm option enables GCC to use the popcnt and lzcnt
- instructions on AMD processors.
- * The -mpopcnt option enables GCC to use the popcnt instructions on
- both AMD and Intel processors.
-
- M68K/ColdFire
-
- * GCC now supports ColdFire 51xx, 5221x, 5225x, 52274, 52277, 5301x
- and 5441x devices.
- * GCC now supports thread-local storage (TLS) on M68K and ColdFire
- processors.
-
- MeP
-
- Support has been added for the Toshiba Media embedded Processor (MeP,
- or mep-elf) embedded target.
-
- MIPS
-
- * GCC now supports MIPS 1004K processors.
- * GCC can now be configured with options --with-arch-32,
- --with-arch-64, --with-tune-32 and --with-tune-64 to control the
- default optimization separately for 32-bit and 64-bit modes.
- * MIPS targets now support an alternative _mcount interface, in which
- register $12 points to the function's save slot for register $31.
- This interface is selected by the -mcount-ra-address option; see
- the documentation for more details.
- * GNU/Linux targets can now generate read-only .eh_frame sections.
- This optimization requires GNU binutils 2.20 or above, and is only
- available if GCC is configured with a suitable version of binutils.
- * GNU/Linux targets can now attach special relocations to indirect
- calls, so that the linker can turn them into direct jumps or
- branches. This optimization requires GNU binutils 2.20 or later,
- and is automatically selected if GCC is configured with an
- appropriate version of binutils. It can be explicitly enabled or
- disabled using the -mrelax-pic-calls command-line option.
- * GCC now generates more heavily-optimized atomic operations on
- Octeon processors.
- * MIPS targets now support the -fstack-protector option.
- * GCC now supports an -msynci option, which specifies that synci is
- enough to flush the instruction cache, without help from the
- operating system. GCC uses this information to optimize
- automatically-generated cache flush operations, such as those used
- for nested functions in C. There is also a --with-synci
- configure-time option, which makes -msynci the default.
- * GCC supports four new function attributes for interrupt handlers:
- interrupt, use_shadow_register_set, keep_interrupts_masked and
- use_debug_exception_return. See the documentation for more details
- about these attributes.
-
- RS/6000 (POWER/PowerPC)
-
- * GCC now supports the Power ISA 2.06, which includes the VSX
- instructions that add vector 64-bit floating point support, new
- population count instructions, and conversions between floating
- point and unsigned types.
- * Support for the power7 processor is now available through the
- -mcpu=power7 and -mtune=power7.
- * GCC will now vectorize loops that contain simple math functions
- like copysign when generating code for altivec or VSX targets.
- * Support for the A2 processor is now available through the -mcpu=a2
- and -mtune=a2 options.
- * Support for the 476 processor is now available through the
- -mcpu={476,476fp} and -mtune={476,476fp} options.
- * Support for the e500mc64 processor is now available through the
- -mcpu=e500mc64 and -mtune=e500mc64 options.
- * GCC can now be configured with options --with-cpu-32,
- --with-cpu-64, --with-tune-32 and --with-tune-64 to control the
- default optimization separately for 32-bit and 64-bit modes.
- * Starting with GCC 4.5.4, vectors of type vector long long or vector
- long are passed and returned in the same method as other vectors
- with the VSX instruction set. Previously the GCC compiler did not
- adhere to the ABI for 128-bit vectors with 64-bit integer base
- types (PR 48857). This is also fixed in the GCC 4.6.1 release.
-
- RX
-
- Support has been added for the Renesas RX Processor (rx-elf) target.
-
-Operating Systems
-
- Windows (Cygwin and MinGW)
-
- * GCC now installs all the major language runtime libraries as DLLs
- when configured with the --enable-shared option.
- * GCC now makes use of the new support for aligned common variables
- in versions of binutils >= 2.20 to fix bugs in the support for SSE
- data types.
- * Improvements to the libffi support library increase the reliability
- of code generated by GCJ on all Windows platforms. Libgcj is
- enabled by default for the first time.
- * Libtool improvements simplify installation by placing the generated
- DLLs in the correct binaries directory.
- * Numerous other minor bugfixes and improvements, and substantial
- enhancements to the Fortran language support library.
-
- >
-
-Other significant improvements
-
- Plugins
-
- * It is now possible to extend the compiler without having to modify
- its source code. A new option -fplugin=file.so tells GCC to load
- the shared object file.so and execute it as part of the compiler.
- The internal documentation describes the details on how plugins can
- interact with the compiler.
-
- Installation changes
-
- * The move to newer autotools changed default installation
- directories and switches to control them: The --with-datarootdir,
- --with-docdir, --with-pdfdir, and --with-htmldir switches are not
- used any more. Instead, you can now use --datarootdir, --docdir,
- --htmldir, and --pdfdir. The default installation directories have
- changed as follows according to the GNU Coding Standards:
-
- datarootdir read-only architecture-independent data root [PREFIX/share]
- localedir locale-specific message catalogs [DATAROOTDIR/locale]
- docdir documentation root [DATAROOTDIR/doc/PACKAGE]
- htmldir html documentation [DOCDIR]
- dvidir dvi documentation [DOCDIR]
- pdfdir pdf documentation [DOCDIR]
- psdir ps documentation [DOCDIR]
- The following variables have new default values:
-
- datadir read-only architecture-independent data [DATAROOTDIR]
- infodir info documentation [DATAROOTDIR/info]
- mandir man documentation [DATAROOTDIR/man]
-
-GCC 4.5.1
-
- This is the [23]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.5.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- All languages
-
- * GCC's new link-time optimizer ([24]-flto) now also works on a few
- non-ELF targets:
- + Cygwin (*-cygwin*)
- + MinGW (*-mingw*)
- + Darwin on x86-64 (x86_64-apple-darwin*)
- LTO is not enabled by default for these targets. To enable LTO, you
- should configure with the --enable-lto option.
-
-GCC 4.5.2
-
- This is the [25]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.5.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.5.3
-
- This is the [26]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.5.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- On the PowerPC compiler, the Altivec builtin functions vec_ld and
- vec_st have been modified to generate the Altivec memory instructions
- LVX and STVX, even if the -mvsx option is used. In the initial GCC 4.5
- release, these builtin functions were changed to generate VSX memory
- reference instructions instead of Altivec memory instructions, but
- there are differences between the two instructions. If the VSX
- instruction set is available, you can now use the new builtin functions
- vec_vsx_ld and vec_vsx_st which always generates the VSX memory
- instructions.
-
-GCC 4.5.4
-
- This is the [27]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.5.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [28]GCC manuals. If that fails, the
- [29]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [30]gcc at gcc.gnu.org. All of [31]our lists have public
- archives.
-
- Copyright (C) [32]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [33]maintained by the GCC team. Last modified
- 2014-12-06[34].
-
-References
-
- 1. http://www.multiprecision.org/
- 2. https://gcc.gnu.org/install/prerequisites.html
- 3. https://gcc.gnu.org/ml/gcc/2010-01/msg00510.html
- 4. http://gcc.gnu.org/gcc-4.4/changes.html#obsoleted
- 5. http://gcc.gnu.org/gcc-4.5/changes.html#x86
- 6. http://www.multiprecision.org/
- 7. https://gcc.gnu.org/PR30789
- 8. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-flto-801
- 9. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-fwhopr-802
- 10. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-fwhole-program-800
- 11. https://gcc.gnu.org/onlinedocs/gcc/Restricted-Pointers.html
- 12. http://gcc.gnu.org/gcc-4.5/cxx0x_status.html
- 13. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#757
- 14. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#176
- 15. https://gcc.gnu.org/onlinedocs/libstdc++/manual/profile_mode.html
- 16. https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.tr24733
- 17. http://sourceware.org/gdb/wiki/STLSupport
- 18. http://gcc.gnu.org/gcc-4.4/changes.html
- 19. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html
- 20. https://gcc.gnu.org/onlinedocs/gfortran/Mixed-Language-Programming.html
- 21. https://gcc.gnu.org/onlinedocs/gfortran/GNU-Fortran-Compiler-Directives.html
- 22. https://gcc.gnu.org/wiki/OOP
- 23. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.1
- 24. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-flto-801
- 25. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.2
- 26. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.3
- 27. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.4
- 28. https://gcc.gnu.org/onlinedocs/
- 29. mailto:gcc-help at gcc.gnu.org
- 30. mailto:gcc at gcc.gnu.org
- 31. https://gcc.gnu.org/lists.html
- 32. http://www.fsf.org/
- 33. https://gcc.gnu.org/about.html
- 34. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.4/index.html
- GCC 4.4 Release Series
-
- March 13, 2012
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.4.7.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.4.6 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.4.7
- March 13, 2012 ([2]changes)
-
- GCC 4.4.6
- April 16, 2011 ([3]changes)
-
- GCC 4.4.5
- October 1, 2010 ([4]changes)
-
- GCC 4.4.4
- April 29, 2010 ([5]changes)
-
- GCC 4.4.3
- January 21, 2010 ([6]changes)
-
- GCC 4.4.2
- October 15, 2009 ([7]changes)
-
- GCC 4.4.1
- July 22, 2009 ([8]changes)
-
- GCC 4.4.0
- April 21, 2009 ([9]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [10]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [11]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [12]GCC
- project web site or contact the [13]GCC development mailing list.
-
- To obtain GCC please use [14]our mirror sites or [15]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [16]GCC manuals. If that fails, the
- [17]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [18]gcc at gcc.gnu.org. All of [19]our lists have public
- archives.
-
- Copyright (C) [20]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [21]maintained by the GCC team. Last modified
- 2014-06-28[22].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.4/changes.html
- 3. http://gcc.gnu.org/gcc-4.4/changes.html
- 4. http://gcc.gnu.org/gcc-4.4/changes.html
- 5. http://gcc.gnu.org/gcc-4.4/changes.html
- 6. http://gcc.gnu.org/gcc-4.4/changes.html
- 7. http://gcc.gnu.org/gcc-4.4/changes.html
- 8. http://gcc.gnu.org/gcc-4.4/changes.html
- 9. http://gcc.gnu.org/gcc-4.4/changes.html
- 10. http://gcc.gnu.org/gcc-4.4/buildstat.html
- 11. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 12. http://gcc.gnu.org/index.html
- 13. mailto:gcc at gcc.gnu.org
- 14. http://gcc.gnu.org/mirrors.html
- 15. http://gcc.gnu.org/svn.html
- 16. https://gcc.gnu.org/onlinedocs/
- 17. mailto:gcc-help at gcc.gnu.org
- 18. mailto:gcc at gcc.gnu.org
- 19. https://gcc.gnu.org/lists.html
- 20. http://www.fsf.org/
- 21. https://gcc.gnu.org/about.html
- 22. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.4/changes.html
- GCC 4.4 Release Series
- Changes, New Features, and Fixes
-
- The latest release in the 4.4 release series is [1]GCC 4.4.7.
-
-Caveats
-
- * __builtin_stdarg_start has been completely removed from GCC.
- Support for <varargs.h> had been deprecated since GCC 4.0. Use
- __builtin_va_start as a replacement.
- * Some of the errors issued by the C++ front end that could be
- downgraded to warnings in previous releases by using -fpermissive
- are now warnings by default. They can be converted into errors by
- using -pedantic-errors.
- * Use of the cpp assertion extension will now emit a warning when
- -Wdeprecated or -pedantic is used. This extension has been
- deprecated for many years, but never warned about.
- * Packed bit-fields of type char were not properly bit-packed on many
- targets prior to GCC 4.4. On these targets, the fix in GCC 4.4
- causes an ABI change. For example there is no longer a 4-bit
- padding between field a and b in this structure:
- struct foo
- {
- char a:4;
- char b:8;
- } __attribute__ ((packed));
- There is a new warning to help identify fields that are affected:
- foo.c:5: note: Offset of packed bit-field 'b' has changed in GCC 4.4
- The warning can be disabled with -Wno-packed-bitfield-compat.
- * On ARM EABI targets, the C++ mangling of the va_list type has been
- changed to conform to the current revision of the EABI. This does
- not affect the libstdc++ library included with GCC.
- * The SCOUNT and POS bits of the MIPS DSP control register are now
- treated as global. Previous versions of GCC treated these fields as
- call-clobbered instead.
- * The MIPS port no longer recognizes the h asm constraint. It was
- necessary to remove this constraint in order to avoid generating
- unpredictable code sequences.
- One of the main uses of the h constraint was to extract the high
- part of a multiplication on 64-bit targets. For example:
- asm ("dmultu\t%1,%2" : "=h" (result) : "r" (x), "r" (y));
- You can now achieve the same effect using 128-bit types:
- typedef unsigned int uint128_t __attribute__((mode(TI)));
- result = ((uint128_t) x * y) >> 64;
- The second sequence is better in many ways. For example, if x and y
- are constants, the compiler can perform the multiplication at
- compile time. If x and y are not constants, the compiler can
- schedule the runtime multiplication better than it can schedule an
- asm statement.
- * Support for a number of older systems and recently unmaintained or
- untested target ports of GCC has been declared obsolete in GCC 4.4.
- Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
- The following ports for individual systems on particular
- architectures have been obsoleted:
- + Generic a.out on IA32 and m68k (i[34567]86-*-aout*,
- m68k-*-aout*)
- + Generic COFF on ARM, H8300, IA32, m68k and SH (arm-*-coff*,
- armel-*-coff*, h8300-*-*, i[34567]86-*-coff*, m68k-*-coff*,
- sh-*-*). This does not affect other more specific targets
- using the COFF object format on those architectures, or the
- more specific H8300 and SH targets (h8300-*-rtems*,
- h8300-*-elf*, sh-*-elf*, sh-*-symbianelf*, sh-*-linux*,
- sh-*-netbsdelf*, sh-*-rtems*, sh-wrs-vxworks).
- + 2BSD on PDP-11 (pdp11-*-bsd)
- + AIX 4.1 and 4.2 on PowerPC (rs6000-ibm-aix4.[12]*,
- powerpc-ibm-aix4.[12]*)
- + Tuning support for Itanium1 (Merced) variants. Note that code
- tuned for Itanium2 should also run correctly on Itanium1.
- * The protoize and unprotoize utilities have been obsoleted and will
- be removed in GCC 4.5. These utilities have not been installed by
- default since GCC 3.0.
- * Support has been removed for all the [2]configurations obsoleted in
- GCC 4.3.
- * Unknown -Wno-* options are now silently ignored by GCC if no other
- diagnostics are issued. If other diagnostics are issued, then GCC
- warns about the unknown options.
- * More information on porting to GCC 4.4 from previous versions of
- GCC can be found in the [3]porting guide for this release.
-
-General Optimizer Improvements
-
- * A new command-line switch -findirect-inlining has been added. When
- turned on it allows the inliner to also inline indirect calls that
- are discovered to have known targets at compile time thanks to
- previous inlining.
- * A new command-line switch -ftree-switch-conversion has been added.
- This new pass turns simple initializations of scalar variables in
- switch statements into initializations from a static array, given
- that all the values are known at compile time and the ratio between
- the new array size and the original switch branches does not exceed
- the parameter --param switch-conversion-max-branch-ratio (default
- is eight).
- * A new command-line switch -ftree-builtin-call-dce has been added.
- This optimization eliminates unnecessary calls to certain builtin
- functions when the return value is not used, in cases where the
- calls can not be eliminated entirely because the function may set
- errno. This optimization is on by default at -O2 and above.
- * A new command-line switch -fconserve-stack directs the compiler to
- minimize stack usage even if it makes the generated code slower.
- This affects inlining decisions.
- * When the assembler supports it, the compiler will now emit unwind
- information using assembler .cfi directives. This makes it possible
- to use such directives in inline assembler code. The new option
- -fno-dwarf2-cfi-asm directs the compiler to not use .cfi
- directives.
- * The [4]Graphite branch has been merged. This merge has brought in a
- new framework for loop optimizations based on a polyhedral
- intermediate representation. These optimizations apply to all the
- languages supported by GCC. The following new code transformations
- are available in GCC 4.4:
- + -floop-interchange performs loop interchange transformations
- on loops. Interchanging two nested loops switches the inner
- and outer loops. For example, given a loop like:
- DO J = 1, M
- DO I = 1, N
- A(J, I) = A(J, I) * C
- ENDDO
- ENDDO
-
- loop interchange will transform the loop as if the user had
- written:
- DO I = 1, N
- DO J = 1, M
- A(J, I) = A(J, I) * C
- ENDDO
- ENDDO
-
- which can be beneficial when N is larger than the caches,
- because in Fortran, the elements of an array are stored in
- memory contiguously by column, and the original loop iterates
- over rows, potentially creating at each access a cache miss.
- + -floop-strip-mine performs loop strip mining transformations
- on loops. Strip mining splits a loop into two nested loops.
- The outer loop has strides equal to the strip size and the
- inner loop has strides of the original loop within a strip.
- For example, given a loop like:
- DO I = 1, N
- A(I) = A(I) + C
- ENDDO
-
- loop strip mining will transform the loop as if the user had
- written:
- DO II = 1, N, 4
- DO I = II, min (II + 3, N)
- A(I) = A(I) + C
- ENDDO
- ENDDO
-
- + -floop-block performs loop blocking transformations on loops.
- Blocking strip mines each loop in the loop nest such that the
- memory accesses of the element loops fit inside caches. For
- example, given a loop like:
- DO I = 1, N
- DO J = 1, M
- A(J, I) = B(I) + C(J)
- ENDDO
- ENDDO
-
- loop blocking will transform the loop as if the user had
- written:
- DO II = 1, N, 64
- DO JJ = 1, M, 64
- DO I = II, min (II + 63, N)
- DO J = JJ, min (JJ + 63, M)
- A(J, I) = B(I) + C(J)
- ENDDO
- ENDDO
- ENDDO
- ENDDO
-
- which can be beneficial when M is larger than the caches,
- because the innermost loop will iterate over a smaller amount
- of data that can be kept in the caches.
- * A new register allocator has replaced the old one. It is called
- integrated register allocator (IRA) because coalescing, register
- live range splitting, and hard register preferencing are done
- on-the-fly during coloring. It also has better integration with the
- reload pass. IRA is a regional register allocator which uses modern
- Chaitin-Briggs coloring instead of Chow's priority coloring used in
- the old register allocator. More info about IRA internals and
- options can be found in the GCC manuals.
- * A new instruction scheduler and software pipeliner, based on the
- selective scheduling approach, has been added. The new pass
- performs instruction unification, register renaming, substitution
- through register copies, and speculation during scheduling. The
- software pipeliner is able to pipeline non-countable loops. The new
- pass is targeted at scheduling-eager in-order platforms. In GCC 4.4
- it is available for the Intel Itanium platform working by default
- as the second scheduling pass (after register allocation) at the
- -O3 optimization level.
- * When using -fprofile-generate with a multi-threaded program, the
- profile counts may be slightly wrong due to race conditions. The
- new -fprofile-correction option directs the compiler to apply
- heuristics to smooth out the inconsistencies. By default the
- compiler will give an error message when it finds an inconsistent
- profile.
- * The new -fprofile-dir=PATH option permits setting the directory
- where profile data files are stored when using -fprofile-generate
- and friends, and the directory used when reading profile data files
- using -fprofile-use and friends.
-
-New warning options
-
- * The new -Wframe-larger-than=NUMBER option directs GCC to emit a
- warning if any stack frame is larger than NUMBER bytes. This may be
- used to help ensure that code fits within a limited amount of stack
- space.
- * The command-line option -Wlarger-than-N is now written as
- -Wlarger-than=N and the old form is deprecated.
- * The new -Wno-mudflap option disables warnings about constructs
- which can not be instrumented when using -fmudflap.
-
-New Languages and Language specific improvements
-
- * Version 3.0 of the [5]OpenMP specification is now supported for the
- C, C++, and Fortran compilers.
- * New character data types, per [6]TR 19769: New character types in
- C, are now supported for the C compiler in -std=gnu99 mode, as
- __CHAR16_TYPE__ and __CHAR32_TYPE__, and for the C++ compiler in
- -std=c++0x and -std=gnu++0x modes, as char16_t and char32_t too.
-
- C family
-
- * A new optimize attribute was added to allow programmers to change
- the optimization level and particular optimization options for an
- individual function. You can also change the optimization options
- via the GCC optimize pragma for functions defined after the pragma.
- The GCC push_options pragma and the GCC pop_options pragma allow
- you temporarily save and restore the options used. The GCC
- reset_options pragma restores the options to what was specified on
- the command line.
- * Uninitialized warnings do not require enabling optimization
- anymore, that is, -Wuninitialized can be used together with -O0.
- Nonetheless, the warnings given by -Wuninitialized will probably be
- more accurate if optimization is enabled.
- * -Wparentheses now warns about expressions such as (!x | y) and (!x
- & y). Using explicit parentheses, such as in ((!x) | y), silences
- this warning.
- * -Wsequence-point now warns within if, while,do while and for
- conditions, and within for begin/end expressions.
- * A new option -dU is available to dump definitions of preprocessor
- macros that are tested or expanded.
-
- C++
-
- * [7]Improved experimental support for the upcoming ISO C++ standard,
- C++0x. Including support for auto, inline namespaces, generalized
- initializer lists, defaulted and deleted functions, new character
- types, and scoped enums.
- * Those errors that may be downgraded to warnings to build legacy
- code now mention -fpermissive when -fdiagnostics-show-option is
- enabled.
- * -Wconversion now warns if the result of a static_cast to enumeral
- type is unspecified because the value is outside the range of the
- enumeral type.
- * -Wuninitialized now warns if a non-static reference or non-static
- const member appears in a class without constructors.
- * G++ now properly implements value-initialization, so objects with
- an initializer of () and an implicitly defined default constructor
- will be zero-initialized before the default constructor is called.
-
- Runtime Library (libstdc++)
-
- * Improved experimental support for the upcoming ISO C++ standard,
- C++0x, including:
- + Support for <chrono>, <condition_variable>, <cstdatomic>,
- <forward_list>, <initializer_list>, <mutex>, <ratio>,
- <system_error>, and <thread>.
- + unique_ptr, <algorithm> additions, exception propagation, and
- support for the new character types in <string> and <limits>.
- + Existing facilities now exploit initializer lists, defaulted
- and deleted functions, and the newly implemented core C++0x
- features.
- + Some standard containers are more efficient together with
- stateful allocators, i.e., no allocator is constructed on the
- fly at element construction time.
- * Experimental support for non-standard pointer types in containers.
- * The long standing libstdc++/30928 has been fixed for targets
- running glibc 2.10 or later.
- * As usual, many small and larger bug fixes, in particular quite a
- few corner cases in <locale>.
-
- Fortran
-
- * GNU Fortran now employs libcpp directly instead of using cc1 as an
- external preprocessor. The [8]-cpp option was added to allow manual
- invocation of the preprocessor without relying on filename
- extensions.
- * The [9]-Warray-temporaries option warns about array temporaries
- generated by the compiler, as an aid to optimization.
- * The [10]-fcheck-array-temporaries option has been added, printing a
- notification at run time, when an array temporary had to be created
- for an function argument. Contrary to -Warray-temporaries the
- warning is only printed if the array is noncontiguous.
- * Improved generation of DWARF debugging symbols
- * If using an intrinsic not part of the selected standard (via -std=
- and -fall-intrinsics) gfortran will now treat it as if this
- procedure were declared EXTERNAL and try to link to a user-supplied
- procedure. -Wintrinsics-std will warn whenever this happens. The
- now-useless option -Wnonstd-intrinsic was removed.
- * The flag -falign-commons has been added to control the alignment of
- variables in COMMON blocks, which is enabled by default in line
- with previous GCC version. Using -fno-align-commons one can force
- commons to be contiguous in memory as required by the Fortran
- standard, however, this slows down the memory access. The option
- -Walign-commons, which is enabled by default, warns when padding
- bytes were added for alignment. The proper solution is to sort the
- common objects by decreasing storage size, which avoids the
- alignment problems.
- * Fortran 2003 support has been extended:
- + Wide characters (ISO 10646, UCS-4, kind=4) and UTF-8 I/O is
- now supported (except internal reads from/writes to wide
- strings). [11]-fbackslash now supports also \unnnn and
- \Unnnnnnnn to enter Unicode characters.
- + Asynchronous I/O (implemented as synchronous I/O) and the
- decimal=, size=, sign=, pad=, blank=, and delim= specifiers
- are now supported in I/O statements.
- + Support for Fortran 2003 structure constructors and for array
- constructor with typespec has been added.
- + Procedure Pointers (but not yet as component in derived types
- and as function results) are now supported.
- + Abstract types, type extension, and type-bound procedures
- (both PROCEDURE and GENERIC but not as operators). Note: As
- CLASS/polymorphyic types are not implemented, type-bound
- procedures with PASS accept as non-standard extension TYPE
- arguments.
- * Fortran 2008 support has been added:
- + The -std=f2008 option and support for the file extensions
- .f2008 and .F2008 has been added.
- + The g0 format descriptor is now supported.
- + The Fortran 2008 mathematical intrinsics ASINH, ACOSH, ATANH,
- ERF, ERFC, GAMMA, LOG_GAMMA, BESSEL_*, HYPOT, and ERFC_SCALED
- are now available (some of them existed as GNU extension
- before). Note: The hyperbolic functions are not yet supporting
- complex arguments and the three- argument version of BESSEL_*N
- is not available.
- + The bit intrinsics LEADZ and TRAILZ have been added.
-
- Java (GCJ)
-
- Ada
-
- * The Ada runtime now supports multilibs on many platforms including
- x86_64, SPARC and PowerPC. Their build is enabled by default.
-
-New Targets and Target Specific Improvements
-
- ARM
-
- * GCC now supports optimizing for the Cortex-A9, Cortex-R4 and
- Cortex-R4F processors and has many other improvements to
- optimization for ARM processors.
- * GCC now supports the VFPv3 variant with 16 double-precision
- registers with -mfpu=vfpv3-d16. The option -mfpu=vfp3 has been
- renamed to -mfpu=vfpv3.
- * GCC now supports the -mfix-cortex-m3-ldrd option to work around an
- erratum on Cortex-M3 processors.
- * GCC now supports the __sync_* atomic operations for ARM EABI
- GNU/Linux.
- * The section anchors optimization is now enabled by default when
- optimizing for ARM.
- * GCC now uses a new EABI-compatible profiling interface for EABI
- targets. This requires a function __gnu_mcount_nc, which is
- provided by GNU libc versions 2.8 and later.
-
- AVR
-
- * The -mno-tablejump option has been deprecated because it has the
- same effect as the -fno-jump-tables option.
- * Added support for these new AVR devices:
- + ATA6289
- + ATtiny13A
- + ATtiny87
- + ATtiny167
- + ATtiny327
- + ATmega8C1
- + ATmega16C1
- + ATmega32C1
- + ATmega8M1
- + ATmega16M1
- + ATmega32M1
- + ATmega32U4
- + ATmega16HVB
- + ATmega4HVD
- + ATmega8HVD
- + ATmega64C1
- + ATmega64M1
- + ATmega16U4
- + ATmega32U6
- + ATmega128RFA1
- + AT90PWM81
- + AT90SCR100
- + M3000F
- + M3000S
- + M3001B
-
- IA-32/x86-64
-
- * Support for Intel AES built-in functions and code generation is
- available via -maes.
- * Support for Intel PCLMUL built-in function and code generation is
- available via -mpclmul.
- * Support for Intel AVX built-in functions and code generation is
- available via -mavx.
- * Automatically align the stack for local variables with alignment
- requirement.
- * GCC can now utilize the SVML library for vectorizing calls to a set
- of C99 functions if -mveclibabi=svml is specified and you link to
- an SVML ABI compatible library.
- * On x86-64, the ABI has been changed in the following cases to
- conform to the x86-64 ABI:
- + Passing/returning structures with flexible array member:
- struct foo
- {
- int i;
- int flex[];
- };
- + Passing/returning structures with complex float member:
- struct foo
- {
- int i;
- __complex__ float f;
- };
- + Passing/returning unions with long double member:
- union foo
- {
- int x;
- long double ld;
- };
- Code built with previous versions of GCC that uses any of these is
- not compatible with code built with GCC 4.4.0 or later.
- * A new target attribute was added to allow programmers to change the
- target options like -msse2 or -march=k8 for an individual function.
- You can also change the target options via the GCC target pragma
- for functions defined after the pragma.
- * GCC can now be configured with options --with-arch-32,
- --with-arch-64, --with-cpu-32, --with-cpu-64, --with-tune-32 and
- --with-tune-64 to control the default optimization separately for
- 32-bit and 64-bit modes.
-
- IA-32/IA64
-
- * Support for __float128 (TFmode) IEEE quad type and corresponding
- TCmode IEEE complex quad type is available via the soft-fp library
- on IA-32/IA64 targets. This includes basic arithmetic operations
- (addition, subtraction, negation, multiplication and division) on
- __float128 real and TCmode complex values, the full set of IEEE
- comparisons between __float128 values, conversions to and from
- float, double and long double floating point types, as well as
- conversions to and from signed or unsigned integer, signed or
- unsigned long integer and signed or unsigned quad (TImode, IA64
- only) integer types. Additionally, all operations generate the full
- set of IEEE exceptions and support the full set of IEEE rounding
- modes.
-
- M68K/ColdFire
-
- * GCC now supports instruction scheduling for ColdFire V1, V3 and V4
- processors. (Scheduling support for ColdFire V2 processors was
- added in GCC 4.3.)
- * GCC now supports the -mxgot option to support programs requiring
- many GOT entries on ColdFire.
- * The m68k-*-linux-gnu target now builds multilibs by default.
-
- MIPS
-
- * MIPS Technologies have extended the original MIPS SVR4 ABI to
- include support for procedure linkage tables (PLTs) and copy
- relocations. These extensions allow GNU/Linux executables to use a
- significantly more efficient code model than the one defined by the
- original ABI.
- GCC support for this code model is available via a new command-line
- option, -mplt. There is also a new configure-time option,
- --with-mips-plt, to make -mplt the default.
- The new code model requires support from the assembler, the linker,
- and the runtime C library. This support is available in binutils
- 2.19 and GLIBC 2.9.
- * GCC can now generate MIPS16 code for 32-bit GNU/Linux executables
- and 32-bit GNU/Linux shared libraries. This feature requires GNU
- binutils 2.19 or above.
- * Support for RMI's XLR processor is now available through the
- -march=xlr and -mtune=xlr options.
- * 64-bit targets can now perform 128-bit multiplications inline,
- instead of relying on a libgcc function.
- * Native GNU/Linux toolchains now support -march=native and
- -mtune=native, which select the host processor.
- * GCC now supports the R10K, R12K, R14K and R16K processors. The
- canonical -march= and -mtune= names for these processors are
- r10000, r12000, r14000 and r16000 respectively.
- * GCC can now work around the side effects of speculative execution
- on R10K processors. Please see the documentation of the
- -mr10k-cache-barrier option for details.
- * Support for the MIPS64 Release 2 instruction set has been added.
- The option -march=mips64r2 enables generation of these
- instructions.
- * GCC now supports Cavium Networks' Octeon processor. This support is
- available through the -march=octeon and -mtune=octeon options.
- * GCC now supports STMicroelectronics' Loongson 2E/2F processors. The
- canonical -march= and -mtune= names for these processors are
- loongson2e and loongson2f.
-
- picochip
-
- Picochip is a 16-bit processor. A typical picoChip contains over 250
- small cores, each with small amounts of memory. There are three
- processor variants (STAN, MEM and CTRL) with different instruction sets
- and memory configurations and they can be chosen using the -mae option.
-
- This port is intended to be a "C" only port.
-
- Power Architecture and PowerPC
-
- * GCC now supports the e300c2, e300c3 and e500mc processors.
- * GCC now supports Xilinx processors with a single-precision FPU.
- * Decimal floating point is now supported for e500 processors.
-
- S/390, zSeries and System z9/z10
-
- * Support for the IBM System z10 EC/BC processor has been added. When
- using the -march=z10 option, the compiler will generate code making
- use of instructions provided by the General-Instruction-Extension
- Facility and the Execute-Extension Facility.
-
- VxWorks
-
- * GCC now supports the thread-local storage mechanism used on
- VxWorks.
-
- Xtensa
-
- * GCC now supports thread-local storage (TLS) for Xtensa processor
- configurations that include the Thread Pointer option. TLS also
- requires support from the assembler and linker; this support is
- provided in the GNU binutils beginning with version 2.19.
-
-Documentation improvements
-
-Other significant improvements
-
-GCC 4.4.1
-
- This is the [12]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.4.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.4.2
-
- This is the [13]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.4.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.4.3
-
- This is the [14]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.4.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.4.4
-
- This is the [15]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.4.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.4.5
-
- This is the [16]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.4.5 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.4.6
-
- This is the [17]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.4.6 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.4.7
-
- This is the [18]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.4.7 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [19]GCC manuals. If that fails, the
- [20]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [21]gcc at gcc.gnu.org. All of [22]our lists have public
- archives.
-
- Copyright (C) [23]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [24]maintained by the GCC team. Last modified
- 2014-12-06[25].
-
-References
-
- 1. http://gcc.gnu.org/gcc-4.4/changes.html#4.4.7
- 2. http://gcc.gnu.org/gcc-4.3/changes.html#obsoleted
- 3. http://gcc.gnu.org/gcc-4.4/porting_to.html
- 4. https://gcc.gnu.org/wiki/Graphite
- 5. http://openmp.org/wp/openmp-specifications/
- 6. http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1040.pdf
- 7. http://gcc.gnu.org/gcc-4.4/cxx0x_status.html
- 8. https://gcc.gnu.org/onlinedocs/gfortran/Preprocessing-Options.html
- 9. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html#index-g_t_0040code_007bWarray-temporaries_007d-125
- 10. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfcheck-array-temporaries_007d-221
- 11. https://gcc.gnu.org/onlinedocs/gfortran/Fortran-Dialect-Options.html#index-g_t_0040code_007bbackslash_007d-34
- 12. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.1
- 13. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.2
- 14. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.3
- 15. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.4
- 16. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.5
- 17. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.6
- 18. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.7
- 19. https://gcc.gnu.org/onlinedocs/
- 20. mailto:gcc-help at gcc.gnu.org
- 21. mailto:gcc at gcc.gnu.org
- 22. https://gcc.gnu.org/lists.html
- 23. http://www.fsf.org/
- 24. https://gcc.gnu.org/about.html
- 25. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.3/index.html
- GCC 4.3 Release Series
-
- Jun 27, 2011
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.3.6.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.3.5 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.3.6
- Jun 27, 2011 ([2]changes)
-
- GCC 4.3.5
- May 22, 2010 ([3]changes)
-
- GCC 4.3.4
- August 4, 2009 ([4]changes)
-
- GCC 4.3.3
- January 24, 2009 ([5]changes)
-
- GCC 4.3.2
- August 27, 2008 ([6]changes)
-
- GCC 4.3.1
- June 6, 2008 ([7]changes)
-
- GCC 4.3.0
- March 5, 2008 ([8]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [9]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [10]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [11]GCC
- project web site or contact the [12]GCC development mailing list.
-
- To obtain GCC please use [13]our mirror sites or [14]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [15]GCC manuals. If that fails, the
- [16]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [17]gcc at gcc.gnu.org. All of [18]our lists have public
- archives.
-
- Copyright (C) [19]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [20]maintained by the GCC team. Last modified
- 2014-06-28[21].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.3/changes.html
- 3. http://gcc.gnu.org/gcc-4.3/changes.html
- 4. http://gcc.gnu.org/gcc-4.3/changes.html
- 5. http://gcc.gnu.org/gcc-4.3/changes.html
- 6. http://gcc.gnu.org/gcc-4.3/changes.html
- 7. http://gcc.gnu.org/gcc-4.3/changes.html
- 8. http://gcc.gnu.org/gcc-4.3/changes.html
- 9. http://gcc.gnu.org/gcc-4.3/buildstat.html
- 10. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 11. http://gcc.gnu.org/index.html
- 12. mailto:gcc at gcc.gnu.org
- 13. http://gcc.gnu.org/mirrors.html
- 14. http://gcc.gnu.org/svn.html
- 15. https://gcc.gnu.org/onlinedocs/
- 16. mailto:gcc-help at gcc.gnu.org
- 17. mailto:gcc at gcc.gnu.org
- 18. https://gcc.gnu.org/lists.html
- 19. http://www.fsf.org/
- 20. https://gcc.gnu.org/about.html
- 21. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.3/changes.html
- GCC 4.3 Release Series
- Changes, New Features, and Fixes
-
- The latest release in the 4.3 release series is [1]GCC 4.3.5.
-
-Caveats
-
- * GCC requires the [2]GMP and [3]MPFR libraries for building all the
- various front-end languages it supports. See the [4]prerequisites
- page for version requirements.
- * ColdFire targets now treat long double as having the same format as
- double. In earlier versions of GCC, they used the 68881 long double
- format instead.
- * The m68k-uclinux target now uses the same calling conventions as
- m68k-linux-gnu. You can select the original calling conventions by
- configuring for m68k-uclinuxoldabi instead. Note that
- m68k-uclinuxoldabi also retains the original 80-bit long double on
- ColdFire targets.
- * The -fforce-mem option has been removed because it has had no
- effect in the last few GCC releases.
- * The i386 -msvr3-shlib option has been removed since it is no longer
- used.
- * Fastcall for i386 has been changed not to pass aggregate arguments
- in registers, following Microsoft compilers.
- * Support for the AOF assembler has been removed from the ARM back
- end; this affects only the targets arm-semi-aof and armel-semi-aof,
- which are no longer recognized. We removed these targets without a
- deprecation period because we discovered that they have been
- unusable since GCC 4.0.0.
- * Support for the TMS320C3x/C4x processor (targets c4x-* and tic4x-*)
- has been removed. This support had been deprecated since GCC 4.0.0.
- * Support for a number of older systems and recently unmaintained or
- untested target ports of GCC has been declared obsolete in GCC 4.3.
- Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
- All GCC ports for the following processor architectures have been
- declared obsolete:
- + Morpho MT (mt-*)
- The following aliases for processor architectures have been
- declared obsolete. Users should use the indicated generic target
- names instead, with compile-time options such as -mcpu or
- configure-time options such as --with-cpu to control the
- configuration more precisely.
- + strongarm*-*-*, ep9312*-*-*, xscale*-*-* (use arm*-*-*
- instead).
- + parisc*-*-* (use hppa*-*-* instead).
- + m680[012]0-*-* (use m68k-*-* instead).
- All GCC ports for the following operating systems have been
- declared obsolete:
- + BeOS (*-*-beos*)
- + kaOS (*-*-kaos*)
- + GNU/Linux using the a.out object format (*-*-linux*aout*)
- + GNU/Linux using version 1 of the GNU C Library
- (*-*-linux*libc1*)
- + Solaris versions before Solaris 7 (*-*-solaris2.[0-6],
- *-*-solaris2.[0-6].*)
- + Miscellaneous System V (*-*-sysv*)
- + WindISS (*-*-windiss*)
- Also, those for some individual systems on particular architectures
- have been obsoleted:
- + UNICOS/mk on DEC Alpha (alpha*-*-unicosmk*)
- + CRIS with a.out object format (cris-*-aout)
- + BSD 4.3 on PA-RISC (hppa1.1-*-bsd*)
- + OSF/1 on PA-RISC (hppa1.1-*-osf*)
- + PRO on PA-RISC (hppa1.1-*-pro*)
- + Sequent PTX on IA32 (i[34567]86-sequent-ptx4*,
- i[34567]86-sequent-sysv4*)
- + SCO Open Server 5 on IA32 (i[34567]86-*-sco3.2v5*)
- + UWIN on IA32 (i[34567]86-*-uwin*) (support for UWIN as a host
- was previously [5]removed in 2001, leaving only the support
- for UWIN as a target now being deprecated)
- + ChorusOS on PowerPC (powerpc-*-chorusos*)
- + All VAX configurations apart from NetBSD and OpenBSD
- (vax-*-bsd*, vax-*-sysv*, vax-*-ultrix*)
- * The [6]-Wconversion option has been modified. Its purpose now is to
- warn for implicit conversions that may alter a value. This new
- behavior is available for both C and C++. Warnings about
- conversions between signed and unsigned integers can be disabled by
- using -Wno-sign-conversion. In C++, they are disabled by default
- unless -Wsign-conversion is explicitly requested. The old behavior
- of -Wconversion, that is, warn for prototypes causing a type
- conversion that is different from what would happen to the same
- argument in the absence of a prototype, has been moved to a new
- option -Wtraditional-conversion, which is only available for C.
- * The -m386, -m486, -mpentium and -mpentiumpro tuning options have
- been removed because they were deprecated for more than 3 GCC major
- releases. Use -mtune=i386, -mtune=i486, -mtune=pentium or
- -mtune=pentiumpro as a replacement.
- * The -funsafe-math-optimizations option now automatically turns on
- -fno-trapping-math in addition to -fno-signed-zeros, as it enables
- reassociation and thus may introduce or remove traps.
- * The -ftree-vectorize option is now on by default under -O3. In
- order to generate code for a SIMD extension, it has to be enabled
- as well: use -maltivec for PowerPC platforms and -msse/-msse2 for
- i?86 and x86_64.
- * More information on porting to GCC 4.3 from previous versions of
- GCC can be found in the [7]porting guide for this release.
-
-General Optimizer Improvements
-
- * The GCC middle-end has been integrated with the [8]MPFR library.
- This allows GCC to evaluate and replace at compile-time calls to
- built-in math functions having constant arguments with their
- mathematically equivalent results. In making use of [9]MPFR, GCC
- can generate correct results regardless of the math library
- implementation or floating point precision of the host platform.
- This also allows GCC to generate identical results regardless of
- whether one compiles in native or cross-compile configurations to a
- particular target. The following built-in functions take advantage
- of this new capability: acos, acosh, asin, asinh, atan2, atan,
- atanh, cbrt, cos, cosh, drem, erf, erfc, exp10, exp2, exp, expm1,
- fdim, fma, fmax, fmin, gamma_r, hypot, j0, j1, jn, lgamma_r, log10,
- log1p, log2, log, pow10, pow, remainder, remquo, sin, sincos, sinh,
- tan, tanh, tgamma, y0, y1 and yn. The float and long double
- variants of these functions (e.g. sinf and sinl) are also handled.
- The sqrt and cabs functions with constant arguments were already
- optimized in prior GCC releases. Now they also use [10]MPFR.
- * A new forward propagation pass on RTL was added. The new pass
- replaces several slower transformations, resulting in compile-time
- improvements as well as better code generation in some cases.
- * A new command-line switch -frecord-gcc-switches has been added to
- GCC, although it is only enabled for some targets. The switch
- causes the command line that was used to invoke the compiler to be
- recorded into the object file that is being created. The exact
- format of this recording is target and binary file format
- dependent, but it usually takes the form of a note section
- containing ASCII text. The switch is related to the -fverbose-asm
- switch, but that one only records the information in the assembler
- output file as comments, so the information never reaches the
- object file.
- * The inliner heuristic is now aware of stack frame consumption. New
- command-line parameters --param large-stack-frame and --param
- large-stack-frame-growth can be used to limit stack frame size
- growth caused by inlining.
- * During feedback directed optimizations, the expected block size the
- memcpy, memset and bzero functions operate on is discovered and for
- cases of commonly used small sizes, specialized inline code is
- generated.
- * __builtin_expect no longer requires its argument to be a compile
- time constant.
- * Interprocedural optimization was reorganized to work on functions
- in SSA form. This enables more precise and cheaper dataflow
- analysis and makes writing interprocedural optimizations easier.
- The following improvements have been implemented on top of this
- framework:
- + Pre-inline optimization: Selected local optimization passes
- are run before the inliner (and other interprocedural passes)
- are executed. This significantly improves the accuracy of code
- growth estimates used by the inliner and reduces the overall
- memory footprint for large compilation units.
- + Early inlining (a simple bottom-up inliner pass inlining only
- functions whose body is smaller than the expected call
- overhead) is now executed with the early optimization passes,
- thus inlining already optimized function bodies into an
- unoptimized function that is subsequently optimized by early
- optimizers. This enables the compiler to quickly eliminate
- abstraction penalty in C++ programs.
- + Interprocedural constant propagation now operate on SSA form
- increasing accuracy of the analysis.
- * A new internal representation for GIMPLE statements has been
- contributed, resulting in compile-time memory savings.
- * The vectorizer was enhanced to support vectorization of outer
- loops, intra-iteration parallelism (loop-aware SLP), vectorization
- of strided accesses and loops with multiple data-types. Run-time
- dependency testing using loop versioning was added. The cost model,
- turned on by -fvect-cost-model, was developed.
-
-New Languages and Language specific improvements
-
- * We have added new command-line options
- -finstrument-functions-exclude-function-list and
- -finstrument-functions-exclude-file-list. They provide more control
- over which functions are annotated by the -finstrument-functions
- option.
-
- C family
-
- * Implicit conversions between generic vector types are now only
- permitted when the two vectors in question have the same number of
- elements and compatible element types. (Note that the restriction
- involves compatible element types, not implicitly-convertible
- element types: thus, a vector type with element type int may not be
- implicitly converted to a vector type with element type unsigned
- int.) This restriction, which is in line with specifications for
- SIMD architectures such as AltiVec, may be relaxed using the flag
- -flax-vector-conversions. This flag is intended only as a
- compatibility measure and should not be used for new code.
- * -Warray-bounds has been added and is now enabled by default for
- -Wall . It produces warnings for array subscripts that can be
- determined at compile time to be always out of bounds.
- -Wno-array-bounds will disable the warning.
- * The constructor and destructor function attributes now accept
- optional priority arguments which control the order in which the
- constructor and destructor functions are run.
- * New [11]command-line options -Wtype-limits,
- -Wold-style-declaration, -Wmissing-parameter-type, -Wempty-body,
- -Wclobbered and -Wignored-qualifiers have been added for finer
- control of the diverse warnings enabled by -Wextra.
- * A new function attribute alloc_size has been added to mark up
- malloc style functions. For constant sized allocations this can be
- used to find out the size of the returned pointer using the
- __builtin_object_size() function for buffer overflow checking and
- similar. This supplements the already built-in malloc and calloc
- constant size handling.
- * Integer constants written in binary are now supported as a GCC
- extension. They consist of a prefix 0b or 0B, followed by a
- sequence of 0 and 1 digits.
- * A new predefined macro __COUNTER__ has been added. It expands to
- sequential integral values starting from 0. In conjunction with the
- ## operator, this provides a convenient means to generate unique
- identifiers.
- * A new command-line option -fdirectives-only has been added. It
- enables a special preprocessing mode which improves the performance
- of applications like distcc and ccache.
- * Fixed-point data types and operators have been added. They are
- based on Chapter 4 of the Embedded-C specification (n1169.pdf).
- Currently, only MIPS targets are supported.
- * Decimal floating-point arithmetic based on draft ISO/IEC TR 24732,
- N1241, is now supported as a GCC extension to C for targets
- i[34567]86-*-linux-gnu, powerpc*-*-linux-gnu, s390*-ibm-linux-gnu,
- and x86_64-*-linux-gnu. The feature introduces new data types
- _Decimal32, _Decimal64, and _Decimal128 with constant suffixes DF,
- DD, and DL.
-
- C++
-
- * [12]Experimental support for the upcoming ISO C++ standard, C++0x.
- * -Wc++0x-compat has been added and is now enabled by default for
- -Wall. It produces warnings for constructs whose meaning differs
- between ISO C++ 1998 and C++0x.
- * The -Wparentheses option now works for C++ as it does for C. It
- warns if parentheses are omitted when operators with confusing
- precedence are nested. It also warns about ambiguous else
- statements. Since -Wparentheses is enabled by -Wall, this may cause
- additional warnings with existing C++ code which uses -Wall. These
- new warnings may be disabled by using -Wall -Wno-parentheses.
- * The -Wmissing-declarations now works for C++ as it does for C.
- * The -fvisibility-ms-compat flag was added, to make it easier to
- port larger projects using shared libraries from Microsoft's Visual
- Studio to ELF and Mach-O systems.
- * C++ attribute handling has been overhauled for template arguments
- (ie dependent types). In particular, __attribute__((aligned(T)));
- works for C++ types.
-
- Runtime Library (libstdc++)
-
- * [13]Experimental support for the upcoming ISO C++ standard, C++0x.
- * Support for TR1 mathematical special functions and regular
- expressions. ([14]Implementation status of TR1)
- * Default what implementations give more elaborate exception strings
- for bad_cast, bad_typeid, bad_exception, and bad_alloc.
- * Header dependencies have been streamlined, reducing unnecessary
- includes and pre-processed bloat.
- * Variadic template implementations of items in <tuple> and
- <functional>.
- * An experimental [15]parallel mode has been added. This is a
- parallel implementation of many C++ Standard library algorithms,
- like std::accumulate, std::for_each, std::transform, or std::sort,
- to give but four examples. These algorithms can be substituted for
- the normal (sequential) libstdc++ algorithms on a piecemeal basis,
- or all existing algorithms can be transformed via the
- -D_GLIBCXX_PARALLEL macro.
- * Debug mode versions of classes in <unordered_set> and
- <unordered_map>.
- * Formal deprecation of <ext/hash_set> and <ext/hash_map>, which are
- now <backward/hash_set> and <backward/hash_map>. This code:
- #include <ext/hash_set>
- __gnu_cxx::hash_set<int> s;
-
- Can be transformed (in order of preference) to:
- #include <tr1/unordered_set>
- std::tr1::unordered_set<int> s;
-
- or
- #include <backward/hash_set>
- __gnu_cxx::hash_set<int> s;
-
- Similar transformations apply to __gnu_cxx::hash_map,
- __gnu_cxx::hash_multimap, __gnu_cxx::hash_set,
- __gnu_cxx::hash_multiset.
-
- Fortran
-
- * Due to the fact that the [16]GMP and [17]MPFR libraries are
- required for all languages, Fortran is no longer special in this
- regard and is available by default.
- * The [18]-fexternal-blas option has been added, which generates
- calls to BLAS routines for intrinsic matrix operations such as
- matmul rather than using the built-in algorithms.
- * Support to give a backtrace (compiler flag -fbacktrace or
- environment variable GFORTRAN_ERROR_BACKTRACE; on glibc systems
- only) or a core dump (-fdump-core, GFORTRAN_ERROR_DUMPCORE) when a
- run-time error occured.
- * GNU Fortran now defines __GFORTRAN__ when it runs the C
- preprocessor (CPP).
- * The [19]-finit-local-zero, -finit-real, -finit-integer,
- -finit-character, and -finit-logical options have been added, which
- can be used to initialize local variables.
- * The intrinsic procedures [20]GAMMA and [21]LGAMMA have been added,
- which calculate the Gamma function and its logarithm. Use EXTERNAL
- gamma if you want to use your own gamma function.
- * GNU Fortran now regards the backslash character as literal (as
- required by the Fortran 2003 standard); using [22]-fbackslash GNU
- Fortran interprets backslashes as C-style escape characters.
- * The [23]interpretation of binary, octal and hexadecimal (BOZ)
- literal constants has been changed. Before they were always
- interpreted as integer; now they are bit-wise transferred as
- argument of INT, REAL, DBLE and CMPLX as required by the Fortran
- 2003 standard, and for real and complex variables in DATA
- statements or when directly assigned to real and complex variables.
- Everywhere else and especially in expressions they are still
- regarded as integer constants.
- * Fortran 2003 support has been extended:
- + Intrinsic statements IMPORT, PROTECTED, VALUE and VOLATILE
- + Pointer intent
- + Intrinsic module ISO_ENV_FORTRAN
- + Interoperability with C (ISO C Bindings)
- + ABSTRACT INTERFACES and PROCEDURE statements (without POINTER
- attribute)
- + Fortran 2003 BOZ
-
- Java (GCJ)
-
- * GCJ now uses the Eclipse Java compiler for its Java parsing needs.
- This enables the use of all 1.5 language features, and fixes most
- existing front end bugs.
- * libgcj now supports all 1.5 language features which require runtime
- support: foreach, enum, annotations, generics, and auto-boxing.
- * We've made many changes to the tools shipped with gcj.
- + The old jv-scan tool has been removed. This tool never really
- worked properly. There is no replacement.
- + gcjh has been rewritten. Some of its more obscure options no
- longer work, but are still recognized in an attempt at
- compatibility. gjavah is a new program with similar
- functionality but different command-line options.
- + grmic and grmiregistry have been rewritten. grmid has been
- added.
- + gjar replaces the old fastjar.
- + gjarsigner (used for signing jars), gkeytool (used for key
- management), gorbd (for CORBA), gserialver (computes
- serialization UIDs), and gtnameserv (also for CORBA) are now
- installed.
- * The ability to dump the contents of the java run time heap to a
- file for off-line analysis has been added. The heap dumps may be
- analyzed with the new gc-analyze tool. They may be generated on
- out-of-memory conditions or on demand and are controlled by the new
- run time class gnu.gcj.util.GCInfo.
- * java.util.TimeZone can now read files from /usr/share/zoneinfo to
- provide correct, updated, timezone information. This means that
- packagers no longer have to update libgcj when a time zone change
- is published.
-
-New Targets and Target Specific Improvements
-
- IA-32/x86-64
-
- * Tuning for Intel Core 2 processors is available via -mtune=core2
- and -march=core2.
- * Tuning for AMD Geode processors is available via -mtune=geode and
- -march=geode.
- * Code generation of block move (memcpy) and block set (memset) was
- rewritten. GCC can now pick the best algorithm (loop, unrolled
- loop, instruction with rep prefix or a library call) based on the
- size of the block being copied and the CPU being optimized for. A
- new option -minline-stringops-dynamically has been added. With this
- option string operations of unknown size are expanded such that
- small blocks are copied by in-line code, while for large blocks a
- library call is used. This results in faster code than
- -minline-all-stringops when the library implementation is capable
- of using cache hierarchy hints. The heuristic choosing the
- particular algorithm can be overwritten via -mstringop-strategy.
- Newly also memset of values different from 0 is inlined.
- * GCC no longer places the cld instruction before string operations.
- Both i386 and x86-64 ABI documents mandate the direction flag to be
- clear at the entry of a function. It is now invalid to set the flag
- in asm statement without reseting it afterward.
- * Support for SSSE3 built-in functions and code generation are
- available via -mssse3.
- * Support for SSE4.1 built-in functions and code generation are
- available via -msse4.1.
- * Support for SSE4.2 built-in functions and code generation are
- available via -msse4.2.
- * Both SSE4.1 and SSE4.2 support can be enabled via -msse4.
- * A new set of options -mpc32, -mpc64 and -mpc80 have been added to
- allow explicit control of x87 floating point precision.
- * Support for __float128 (TFmode) IEEE quad type and corresponding
- TCmode IEEE complex quad type is available via the soft-fp library
- on x86_64 targets. This includes basic arithmetic operations
- (addition, subtraction, negation, multiplication and division) on
- __float128 real and TCmode complex values, the full set of IEEE
- comparisons between __float128 values, conversions to and from
- float, double and long double floating point types, as well as
- conversions to and from signed or unsigned integer, signed or
- unsigned long integer and signed or unsigned quad (TImode) integer
- types. Additionally, all operations generate the full set of IEEE
- exceptions and support the full set of IEEE rounding modes.
- * GCC can now utilize the ACML library for vectorizing calls to a set
- of C99 functions on x86_64 if -mveclibabi=acml is specified and you
- link to an ACML ABI compatible library.
-
- ARM
-
- * Compiler and Library support for Thumb-2 and the ARMv7 architecture
- has been added.
-
- CRIS
-
- New features
-
- * Compiler and Library support for the CRIS v32 architecture, as
- found in Axis Communications ETRAX FS and ARTPEC-3 chips, has been
- added.
-
- Configuration changes
-
- * The cris-*-elf target now includes support for CRIS v32, including
- libraries, through the -march=v32 option.
- * A new crisv32-*-elf target defaults to generate code for CRIS v32.
- * A new crisv32-*-linux* target defaults to generate code for CRIS
- v32.
- * The cris-*-aout target has been obsoleted.
-
- Improved support for built-in functions
-
- * GCC can now use the lz and swapwbr instructions to implement the
- __builtin_clz, __builtin_ctz and __builtin_ffs family of functions.
- * __builtin_bswap32 is now implemented using the swapwb instruction,
- when available.
-
- m68k and ColdFire
-
- New features
-
- * Support for several new ColdFire processors has been added. You can
- generate code for them using the new -mcpu option.
- * All targets now support ColdFire processors.
- * m68k-uclinux targets have improved support for C++ constructors and
- destructors, and for shared libraries.
- * It is now possible to set breakpoints on the first or last line of
- a function, even if there are no statements on that line.
-
- Optimizations
-
- * Support for sibling calls has been added.
- * More use is now made of the ColdFire mov3q instruction.
- * __builtin_clz is now implemented using the ff1 ColdFire
- instruction, when available.
- * GCC now honors the -m68010 option. 68010 code now uses clr rather
- than move to zero volatile memory.
- * 68020 targets and above can now use symbol(index.size*scale)
- addresses for indexed array accesses. Earlier compilers would
- always load the symbol into a base register first.
-
- Configuration changes
-
- * All m68k and ColdFire targets now allow the default processor to be
- set at configure time using --with-cpu.
- * A --with-arch configuration option has been added. This option
- allows you to restrict a target to ColdFire or non-ColdFire
- processors.
-
- Preprocessor macros
-
- * An __mcfv*__ macro is now defined for all ColdFire targets.
- (Earlier versions of GCC only defined __mcfv4e__.)
- * __mcf_cpu_*, __mcf_family_* and __mcffpu__ macros have been added.
- * All targets now define __mc68010 and __mc68010__ when generating
- 68010 code.
-
- Command-line changes
-
- * New command-line options -march, -mcpu, -mtune and -mhard-float
- have been added. These options apply to both m68k and ColdFire
- targets.
- * -mno-short, -mno-bitfield and -mno-rtd are now accepted as negative
- versions of -mshort, etc.
- * -fforce-addr has been removed. It is now ignored by the compiler.
-
- Other improvements
-
- * ColdFire targets now try to maintain a 4-byte-aligned stack where
- possible.
- * m68k-uclinux targets now try to avoid situations that lead to the
- load-time error: BINFMT_FLAT: reloc outside program.
-
- MIPS
-
- Changes to existing configurations
-
- * libffi and libjava now support all three GNU/Linux ABIs: o32, n32
- and n64. Every GNU/Linux configuration now builds these libraries
- by default.
- * GNU/Linux configurations now generate -mno-shared code unless
- overridden by -fpic, -fPIC, -fpie or -fPIE.
- * mipsisa32*-linux-gnu configurations now generate hard-float code by
- default, just like other mipsisa32* and mips*-linux-gnu
- configurations. You can build a soft-float version of any
- mips*-linux-gnu configuration by passing --with-float=soft to
- configure.
- * mips-wrs-vxworks now supports run-time processes (RTPs).
-
- Changes to existing command-line options
-
- * The -march and -mtune options no longer accept 24k as a processor
- name. Please use 24kc, 24kf2_1 or 24kf1_1 instead.
- * The -march and -mtune options now accept 24kf2_1, 24kef2_1 and
- 34kf2_1 as synonyms for 24kf, 24kef and 34kf respectively. The
- options also accept 24kf1_1, 24kef1_1 and 34kf1_1 as synonyms for
- 24kx, 24kex and 34kx.
-
- New configurations
-
- GCC now supports the following configurations:
- * mipsisa32r2*-linux-gnu*, which generates MIPS32 revision 2 code by
- default. Earlier releases also recognized this configuration, but
- they treated it in the same way as mipsisa32*-linux-gnu*. Note that
- you can customize any mips*-linux-gnu* configuration to a
- particular ISA or processor by passing an appropriate --with-arch
- option to configure.
- * mipsisa*-sde-elf*, which provides compatibility with MIPS
- Technologies' SDE toolchains. The configuration uses the SDE
- libraries by default, but you can use it like other newlib-based
- ELF configurations by passing --with-newlib to configure. It is the
- only configuration besides mips64vr*-elf* to build MIPS16 as well
- as non-MIPS16 libraries.
- * mipsisa*-elfoabi*, which is similar to the general mipsisa*-elf*
- configuration, but uses the o32 and o64 ABIs instead of the 32-bit
- and 64-bit forms of the EABI.
-
- New processors and application-specific extensions
-
- * Support for the SmartMIPS ASE is available through the new
- -msmartmips option.
- * Support for revision 2 of the DSP ASE is available through the new
- -mdspr2 option. A new preprocessor macro called __mips_dsp_rev
- indicates the revision of the ASE in use.
- * Support for the 4KS and 74K families of processors is available
- through the -march and -mtune options.
-
- Improved support for built-in functions
-
- * GCC can now use load-linked, store-conditional and sync
- instructions to implement atomic built-in functions such as
- __sync_fetch_and_add. The memory reference must be 4 bytes wide for
- 32-bit targets and either 4 or 8 bytes wide for 64-bit targets.
- * GCC can now use the clz and dclz instructions to implement the
- __builtin_ctz and __builtin_ffs families of functions.
- * There is a new __builtin___clear_cache function for flushing the
- instruction cache. GCC expands this function inline on MIPS32
- revision 2 targets, otherwise it calls the function specified by
- -mcache-flush-func.
-
- MIPS16 improvements
-
- * GCC can now compile objects that contain a mixture of MIPS16 and
- non-MIPS16 code. There are two new attributes, mips16 and nomips16,
- for specifying which mode a function should use.
- * A new option called -minterlink-mips16 makes non-MIPS16 code
- link-compatible with MIPS16 code.
- * After many bug fixes, the long-standing MIPS16 -mhard-float support
- should now work fairly reliably.
- * GCC can now use the MIPS16e save and restore instructions.
- * -fsection-anchors now works in MIPS16 mode. MIPS16 code compiled
- with -G0 -fsection-anchors is often smaller than code compiled with
- -G8. However, please note that you must usually compile all objects
- in your application with the same -G option; see the documentation
- of -G for details.
- * A new option called-mcode-readable specifies which instructions are
- allowed to load from the code segment. -mcode-readable=yes is the
- default and says that any instruction may load from the code
- segment. The other alternatives are -mcode-readable=pcrel, which
- says that only PC-relative MIPS16 instructions may load from the
- code segment, and -mcode-readable=no, which says that no
- instruction may do so. Please see the documentation for more
- details, including example uses.
-
- Small-data improvements
-
- There are three new options for controlling small data:
- * -mno-extern-sdata, which disables small-data accesses for
- externally-defined variables. Code compiled with -Gn
- -mno-extern-sdata will be link-compatible with any -G setting
- between -G0 and -Gn inclusive.
- * -mno-local-sdata, which disables the use of small-data sections for
- data that is not externally visible. This option can be a useful
- way of reducing small-data usage in less performance-critical parts
- of an application.
- * -mno-gpopt, which disables the use of the $gp register while still
- honoring the -G limit when placing externally-visible data. This
- option implies -mno-extern-sdata and -mno-local-sdata and it can be
- useful in situations where $gp does not necessarily hold the
- expected value.
-
- Miscellaneous improvements
-
- * There is a new option called -mbranch-cost for tweaking the
- perceived cost of branches.
- * If GCC is configured to use a version of GAS that supports the
- .gnu_attribute directive, it will use that directive to record
- certain properties of the output code. .gnu_attribute is new to GAS
- 2.18.
- * There are two new function attributes, near and far, for overriding
- the command-line setting of -mlong-calls on a function-by-function
- basis.
- * -mfp64, which previously required a 64-bit target, now works with
- MIPS32 revision 2 targets as well. The mipsisa*-elfoabi* and
- mipsisa*-sde-elf* configurations provide suitable library support.
- * GCC now recognizes the -mdmx and -mmt options and passes them down
- to the assembler. It does nothing else with the options at present.
-
- SPU (Synergistic Processor Unit) of the Cell Broadband Engine Architecture
- (BEA)
-
- * Support has been added for this new architecture.
-
- RS6000 (POWER/PowerPC)
-
- * Support for the PowerPC 750CL paired-single instructions has been
- added with a new powerpc-*-linux*paired* target configuration. It
- is enabled by an associated -mpaired option and can be accessed
- using new built-in functions.
- * Support for auto-detecting architecture and system configuration to
- auto-select processor optimization tuning.
- * Support for VMX on AIX 5.3 has been added.
- * Support for AIX Version 6.1 has been added.
-
- S/390, zSeries and System z9
-
- * Support for the IBM System z9 EC/BC processor (z9 GA3) has been
- added. When using the -march=z9-ec option, the compiler will
- generate code making use of instructions provided by the decimal
- floating point facility and the floating point conversion facility
- (pfpo). Besides the instructions used to implement decimal floating
- point operations these facilities also contain instructions to move
- between general purpose and floating point registers and to modify
- and copy the sign-bit of floating point values.
- * When the -march=z9-ec option is used the new
- -mhard-dfp/-mno-hard-dfp options can be used to specify whether the
- decimal floating point hardware instructions will be used or not.
- If none of them is given the hardware support is enabled by
- default.
- * The -mstack-guard option can now be omitted when using stack
- checking via -mstack-size in order to let GCC choose a sensible
- stack guard value according to the frame size of each function.
- * Various changes to improve performance of generated code have been
- implemented, including:
- + The condition code set by an add logical with carry
- instruction is now available for overflow checks like: a + b +
- carry < b.
- + The test data class instruction is now used to implement
- sign-bit and infinity checks of binary and decimal floating
- point numbers.
-
- SPARC
-
- * Support for the Sun UltraSPARC T2 (Niagara 2) processor has been
- added.
-
- Xtensa
-
- * Stack unwinding for exception handling now uses by default a
- specialized version of DWARF unwinding. This is not
- binary-compatible with the setjmp/longjmp (sjlj) unwinding used for
- Xtensa with previous versions of GCC.
- * For Xtensa processors that include the Conditional Store option,
- the built-in functions for atomic memory access are now implemented
- using S32C1I instructions.
- * If the Xtensa NSA option is available, GCC will use it to implement
- the __builtin_ctz and __builtin_clz functions.
-
-Documentation improvements
-
- * Existing libstdc++ documentation has been edited and restructured
- into a single DocBook XML manual. The results can be viewed online
- [24]here.
-
-Other significant improvements
-
- * The compiler's --help command-line option has been extended so that
- it now takes an optional set of arguments. These arguments restrict
- the information displayed to specific classes of command-line
- options, and possibly only a subset of those options. It is also
- now possible to replace the descriptive text associated with each
- displayed option with an indication of its current value, or for
- binary options, whether it has been enabled or disabled.
- Here are some examples. The following will display all the options
- controlling warning messages:
- --help=warnings
-
- Whereas this will display all the undocumented, target specific
- options:
- --help=target,undocumented
-
- This sequence of commands will display the binary optimizations
- that are enabled by -O3:
- gcc -c -Q -O3 --help=optimizers > /tmp/O3-opts
- gcc -c -Q -O2 --help=optimizers > /tmp/O2-opts
- diff /tmp/O2-opts /tmp/O3-opts | grep enabled
-
- * The configure options --with-pkgversion and --with-bugurl have been
- added. These allow distributors of GCC to include a
- distributor-specific string in manuals and --version output and to
- specify the URL for reporting bugs in their versions of GCC.
-
-GCC 4.3.1
-
- This is the [25]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.3.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-Target Specific Changes
-
- IA-32/x86-64
-
- ABI changes
-
- * Starting with GCC 4.3.1, decimal floating point variables are
- aligned to their natural boundaries when they are passed on the
- stack for i386.
-
- Command-line changes
-
- * Starting with GCC 4.3.1, the -mcld option has been added to
- automatically generate a cld instruction in the prologue of
- functions that use string instructions. This option is used for
- backward compatibility on some operating systems and can be enabled
- by default for 32-bit x86 targets by configuring GCC with the
- --enable-cld configure option.
-
-GCC 4.3.2
-
- This is the [26]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.3.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.3.3
-
- This is the [27]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.3.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.3.4
-
- This is the [28]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.3.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.3.5
-
- This is the [29]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.3.5 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.3.6
-
- This is the [30]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.3.6 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [31]GCC manuals. If that fails, the
- [32]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [33]gcc at gcc.gnu.org. All of [34]our lists have public
- archives.
-
- Copyright (C) [35]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [36]maintained by the GCC team. Last modified
- 2014-06-28[37].
-
-References
-
- 1. http://gcc.gnu.org/gcc-4.3/changes.html#4.3.5
- 2. http://gmplib.org/
- 3. http://www.mpfr.org/
- 4. https://gcc.gnu.org/install/prerequisites.html
- 5. https://gcc.gnu.org/ml/gcc-announce/2001/msg00000.html
- 6. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#Warning-Options
- 7. http://gcc.gnu.org/gcc-4.3/porting_to.html
- 8. http://www.mpfr.org/
- 9. http://www.mpfr.org/
- 10. http://www.mpfr.org/
- 11. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
- 12. http://gcc.gnu.org/gcc-4.3/cxx0x_status.html
- 13. http://gcc.gnu.org/gcc-4.3/cxx0x_status.html
- 14. https://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt01ch01.html#m anual.intro.status.standard.tr1
- 15. https://gcc.gnu.org/onlinedocs/libstdc++/manual/parallel_mode.html
- 16. http://gmplib.org/
- 17. http://www.mpfr.org/
- 18. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#Code-Gen-Options
- 19. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfinit-local-zero_007d-167
- 20. https://gcc.gnu.org/onlinedocs/gcc-4.3.0/gfortran/GAMMA.html
- 21. https://gcc.gnu.org/onlinedocs/gcc-4.3.0/gfortran/LGAMMA.html
- 22. https://gcc.gnu.org/onlinedocs/gfortran/Fortran-Dialect-Options.html
- 23. https://gcc.gnu.org/onlinedocs/gfortran/BOZ-literal-constants.html
- 24. https://gcc.gnu.org/onlinedocs/libstdc++/
- 25. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.1
- 26. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.2
- 27. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.3
- 28. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.4
- 29. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.5
- 30. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.6
- 31. https://gcc.gnu.org/onlinedocs/
- 32. mailto:gcc-help at gcc.gnu.org
- 33. mailto:gcc at gcc.gnu.org
- 34. https://gcc.gnu.org/lists.html
- 35. http://www.fsf.org/
- 36. https://gcc.gnu.org/about.html
- 37. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.2/index.html
- GCC 4.2 Release Series
-
- May 19, 2008
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.2.4.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.2.3 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.2.4
- May 19, 2008 ([2]changes)
-
- GCC 4.2.3
- February 1, 2008 ([3]changes)
-
- GCC 4.2.2
- October 7, 2007 ([4]changes)
-
- GCC 4.2.1
- July 18, 2007 ([5]changes)
-
- GCC 4.2.0
- May 13, 2007 ([6]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [7]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [8]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [9]GCC project
- web site or contact the [10]GCC development mailing list.
-
- To obtain GCC please use [11]our mirror sites or [12]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [13]GCC manuals. If that fails, the
- [14]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [15]gcc at gcc.gnu.org. All of [16]our lists have public
- archives.
-
- Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [18]maintained by the GCC team. Last modified
- 2014-06-28[19].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.2/changes.html
- 3. http://gcc.gnu.org/gcc-4.2/changes.html
- 4. http://gcc.gnu.org/gcc-4.2/changes.html
- 5. http://gcc.gnu.org/gcc-4.2/changes.html
- 6. http://gcc.gnu.org/gcc-4.2/changes.html
- 7. http://gcc.gnu.org/gcc-4.2/buildstat.html
- 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 9. http://gcc.gnu.org/index.html
- 10. mailto:gcc at gcc.gnu.org
- 11. http://gcc.gnu.org/mirrors.html
- 12. http://gcc.gnu.org/svn.html
- 13. https://gcc.gnu.org/onlinedocs/
- 14. mailto:gcc-help at gcc.gnu.org
- 15. mailto:gcc at gcc.gnu.org
- 16. https://gcc.gnu.org/lists.html
- 17. http://www.fsf.org/
- 18. https://gcc.gnu.org/about.html
- 19. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.2/changes.html
- GCC 4.2 Release Series
- Changes, New Features, and Fixes
-
-Caveats
-
- * GCC no longer accepts the -fshared-data option. This option has had
- no effect in any GCC 4 release; the targets to which the option
- used to apply had been removed before GCC 4.0.
-
-General Optimizer Improvements
-
- * New command-line options specify the possible relationships among
- parameters and between parameters and global data. For example,
- -fargument-noalias-anything specifies that arguments do not alias
- any other storage.
- Each language will automatically use whatever option is required by
- the language standard. You should not need to use these options
- yourself.
-
-New Languages and Language specific improvements
-
- * [1]OpenMP is now supported for the C, C++ and Fortran compilers.
- * New command-line options -fstrict-overflow and -Wstrict-overflow
- have been added. -fstrict-overflow tells the compiler that it may
- assume that the program follows the strict signed overflow
- semantics permitted for the language: for C and C++ this means that
- the compiler may assume that signed overflow does not occur. For
- example, a loop like
- for (i = 1; i > 0; i *= 2)
-
- is presumably intended to continue looping until i overflows. With
- -fstrict-overflow, the compiler may assume that signed overflow
- will not occur, and transform this into an infinite loop.
- -fstrict-overflow is turned on by default at -O2, and may be
- disabled via -fno-strict-overflow. The -Wstrict-overflow option may
- be used to warn about cases where the compiler assumes that signed
- overflow will not occur. It takes five different levels:
- -Wstrict-overflow=1 to 5. See the [2]documentation for details.
- -Wstrict-overflow=1 is enabled by -Wall.
- * The new command-line option -fno-toplevel-reorder directs GCC to
- emit top-level functions, variables, and asm statements in the same
- order that they appear in the input file. This is intended to
- support existing code which relies on a particular ordering (for
- example, code which uses top-level asm statements to switch
- sections). For new code, it is generally better to use function and
- variable attributes. The -fno-toplevel-reorder option may be used
- for most cases which currently use -fno-unit-at-a-time. The
- -fno-unit-at-a-time option will be removed in some future version
- of GCC. If you know of a case which requires -fno-unit-at-a-time
- which is not fixed by -fno-toplevel-reorder, please open a bug
- report.
-
- C family
-
- * The pragma redefine_extname will now macro expand its tokens for
- compatibility with SunPRO.
- * In the next release of GCC, 4.3, -std=c99 or -std=gnu99 will direct
- GCC to handle inline functions as specified in the C99 standard. In
- preparation for this, GCC 4.2 will warn about any use of non-static
- inline functions in gnu99 or c99 mode. This new warning may be
- disabled with the new gnu_inline function attribute or the new
- -fgnu89-inline command-line option. Also, GCC 4.2 and later will
- define one of the preprocessor macros __GNUC_GNU_INLINE__ or
- __GNUC_STDC_INLINE__ to indicate the semantics of inline functions
- in the current compilation.
- * A new command-line option -Waddress has been added to warn about
- suspicious uses of memory addresses as, for example, using the
- address of a function in a conditional expression, and comparisons
- against the memory address of a string literal. This warning is
- enabled by -Wall.
-
- C++
-
- * C++ visibility handling has been overhauled.
- Restricted visiblity is propagated from classes to members, from
- functions to local statics, and from templates and template
- arguments to instantiations, unless the latter has explicitly
- declared visibility.
- The visibility attribute for a class must come between the
- class-key and the name, not after the closing brace.
- Attributes are now allowed for enums and elaborated-type-specifiers
- that only declare a type.
- Members of the anonymous namespace are now local to a particular
- translation unit, along with any other declarations which use them,
- though they are still treated as having external linkage for
- language semantics.
- * The (undocumented) extension which permitted templates with default
- arguments to be bound to template template parameters with fewer
- parameters has been removed. For example:
- template <template <typename> class C>
- void f(C<double>) {}
-
- template <typename T, typename U = int>
- struct S {};
-
- template void f(S<double>);
-
- is no longer accepted by G++. The reason this code is not accepted
- is that S is a template with two parameters; therefore, it cannot
- be bound to C which has only one parameter.
- * The <?, >?, <?=, and >?= operators, deprecated in previous GCC
- releases, have been removed.
- * The command-line option -fconst-strings, deprecated in previous GCC
- releases, has been removed.
- * The configure variable enable-__cxa_atexit is now enabled by
- default for more targets. Enabling this variable is necessary in
- order for static destructors to be executed in the correct order,
- but it depends upon the presence of a non-standard C library in the
- target library in order to work. The variable is now enabled for
- more targets which are known to have suitable C libraries.
- * -Wextra will produce warnings for if statements with a semicolon as
- the only body, to catch code like:
- if (a);
- return 1;
- return 0;
-
- To suppress the warning in valid cases, use { } instead.
- * The C++ frontend now also produces strict aliasing warnings when
- -fstrict-aliasing -Wstrict-aliasing is in effect.
-
- Runtime Library (libstdc++)
-
- * Added support for TR1 <random>, <complex>, and C compatibility
- headers. In addition, a lock-free version of shared_ptr was
- contributed as part of Phillip Jordan's Google Summer of Code
- project on lock-free containers. ([3]Implementation status of TR1)
- * In association with the Summer of Code work on lock-free
- containers, the interface for atomic builtins was adjusted,
- creating simpler alternatives for non-threaded code paths. Also,
- usage was consolidated and all elements were moved from namespace
- std to namespace__gnu_cxx. Affected interfaces are the functions
- __exchange_and_add, __atomic_add, and the objects __mutex,
- __recursive_mutex, and __scoped_lock.
- * Support for versioning weak symbol names via namespace association
- was added. However, as this changes the names of exported symbols,
- this is turned off by default in the current ABI. Intrepid users
- can enable this feature by using
- --enable-symvers=gnu-versioned-namespace during configuration.
- * Revised, simplified, and expanded policy-based associative
- containers, including data types for tree and trie forms
- (basic_tree, tree, trie), lists (list_update), and both
- collision-chaining and probing hash-based containers
- (basic_hash_table, cc_hash_table, gp_hash_table). More details per
- the [4]documentation.
- * The implementation of the debug mode was modified, whereby the
- debug namespaces were nested inside of namespace std and namespace
- __gnu_cxx in order to resolve some long standing corner cases
- involving name lookup. Debug functionality from the policy-based
- data structures was consolidated and enabled with the single macro,
- _GLIBCXX_DEBUG. See PR 26142 for more information.
- * Added extensions for type traits: __conditional_type,
- __numeric_traits, __add_unsigned, __removed_unsigned, __enable_if.
- * Added a typelist implementation for compile-time meta-programming.
- Elements for typelist construction and operation can be found
- within namespace __gnu_cxx::typelist.
- * Added a new allocator, __gnu_cxx::throw_allocator, for testing
- exception-safety.
- * Enabled library-wide visibility control, allowing -fvisibility to
- be used.
- * Consolidated all nested namespaces and the conversion of
- __gnu_internal implementation-private details to anonymous
- namespaces whenever possible.
- * Implemented LWG resolutions DR 431 and DR 538.
-
- Fortran
-
- * Support for allocatable components has been added (TR 15581 and
- Fortran 2003).
- * Support for the Fortran 2003 streaming IO extension has been added.
- * The GNU Fortran compiler now uses 4-byte record markers by default
- for unformatted files to be compatible with g77 and most other
- compilers. The implementation allows for records greater than 2 GB
- and is compatible with several other compilers. Older versions of
- gfortran used 8-byte record markers by default (on most systems).
- In order to change the length of the record markers, e.g. to read
- unformatted files created by older gfortran versions, the
- [5]-frecord-marker=8 option can be used.
-
- Java (GCJ)
-
- * A new command-line option -static-libgcj has been added for targets
- that use a linker compatible with GNU Binutils. As its name
- implies, this causes libgcj to be linked statically. In some cases
- this causes the resulting executable to start faster and use less
- memory than if the shared version of libgcj were used. However
- caution should be used as it can also cause essential parts of the
- library to be omitted. Some of these issues are discussed in:
- [6]https://gcc.gnu.org/wiki/Statically_linking_libgcj
- * fastjar is no longer bundled with GCC. To build libgcj, you will
- need either InfoZIP (both zip and unzip) or an external jar
- program. In the former case, the GCC build will install a jar shell
- script that is based on InfoZIP and provides the same functionality
- as fastjar.
-
-New Targets and Target Specific Improvements
-
- IA-32/x86-64
-
- * -mtune=generic can now be used to generate code running well on
- common x86 chips. This includes AMD Athlon, AMD Opteron, Intel
- Pentium-M, Intel Pentium 4 and Intel Core 2.
- * -mtune=native and -march=native will produce code optimized for the
- host architecture as detected using the cpuid instruction.
- * Added a new command-line option -fstackrealign and and
- __attribute__ ((force_align_arg_pointer)) to realign the stack at
- runtime. This allows functions compiled with a vector-aligned stack
- to be invoked from legacy objects that keep only word-alignment.
-
- SPARC
-
- * The default CPU setting has been changed from V7 to V9 in 32-bit
- mode on Solaris 7 and above. This is already the case in 64-bit
- mode. It can be overridden by specifying --with-cpu at configure
- time.
- * Back-end support of built-in functions for atomic memory access has
- been implemented.
- * Support for the Sun UltraSPARC T1 (Niagara) processor has been
- added.
-
- M32C
-
- * Various bug fixes have made some functions (notably, functions
- returning structures) incompatible with previous releases.
- Recompiling all libraries is recommended. Note that code quality
- has considerably improved since 4.1, making a recompile even more
- beneficial.
-
- MIPS
-
- * Added support for the Broadcom SB-1A core.
-
- IA-64
-
- * Added support for IA-64 data and control speculation. By default
- speculation is enabled only during second scheduler pass. A number
- of machine flags was introduced to control the usage of speculation
- for both scheduler passes.
-
- HPPA
-
- * Added Java language support (libffi and libjava) for 32-bit HP-UX
- 11 target.
-
-Obsolete Systems
-
-Documentation improvements
-
- PDF Documentation
-
- * A make pdf target has been added to the top-level makefile,
- enabling automated production of PDF documentation files.
- (Front-ends external to GCC should modify their Make-lang.in file
- to add a lang.pdf: target.)
-
-Other significant improvements
-
- Build system improvements
-
- * All the components of the compiler are now bootstrapped by default.
- This improves the resilience to bugs in the system compiler or
- binary compatibility problems, as well as providing better testing
- of GCC 4.2 itself. In addition, if you build the compiler from a
- combined tree, the assembler, linker, etc. will also be
- bootstrapped (i.e. built with themselves).
- You can disable this behavior, and go back to the pre-GCC 4.2 set
- up, by configuring GCC with --disable-bootstrap.
- * The rules that configure follows to find target tools resemble more
- closely the locations that the built compiler will search. In
- addition, you can use the new configure option --with-target-tools
- to specify where to find the target tools used during the build,
- without affecting what the built compiler will use.
- This can be especially useful when building packages of GCC. For
- example, you may want to build GCC with GNU as or ld, even if the
- resulting compiler to work with the native assembler and linker. To
- do so, you can use --with-target-tools to point to the native
- tools.
-
- Incompatible changes to the build system
-
- * Front-ends external to GCC should modify their Make-lang.in file to
- replace double-colon rules (e.g. dvi::) with normal rules (like
- lang.dvi:). Front-end makefile hooks do not use double-colon rules
- anymore.
- * Up to GCC 4.1, a popular way to specify the target tools used
- during the build was to create directories named gas, binutils,
- etc. in the build tree, and create links to the tools from there.
- This does not work any more when the compiler is bootstrapped. The
- new configure option --with-target-tools provides a better way to
- achieve the same effect, and works for all native and cross
- settings.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [7]GCC manuals. If that fails, the
- [8]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [9]gcc at gcc.gnu.org. All of [10]our lists have public
- archives.
-
- Copyright (C) [11]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [12]maintained by the GCC team. Last modified
- 2014-06-28[13].
-
-References
-
- 1. http://gcc.gnu.org/projects/gomp/
- 2. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
- 3. https://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt01ch01.html#manual.intro.status.standard.tr1
- 4. https://gcc.gnu.org/onlinedocs/libstdc++/ext/pb_ds/index.html
- 5. https://gcc.gnu.org/onlinedocs/gfortran/Runtime-Options.html
- 6. https://gcc.gnu.org/wiki/Statically_linking_libgcj
- 7. https://gcc.gnu.org/onlinedocs/
- 8. mailto:gcc-help at gcc.gnu.org
- 9. mailto:gcc at gcc.gnu.org
- 10. https://gcc.gnu.org/lists.html
- 11. http://www.fsf.org/
- 12. https://gcc.gnu.org/about.html
- 13. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.1/index.html
- GCC 4.1 Release Series
-
- February 13, 2007
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.1.2.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.1.1 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.1.2
- February 13, 2007 ([2]changes)
-
- GCC 4.1.1
- May 24, 2006 ([3]changes)
-
- GCC 4.1.0
- February 28, 2006 ([4]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [5]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [6]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [7]GCC project
- web site or contact the [8]GCC development mailing list.
-
- To obtain GCC please use [9]our mirror sites or [10]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [11]GCC manuals. If that fails, the
- [12]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [13]gcc at gcc.gnu.org. All of [14]our lists have public
- archives.
-
- Copyright (C) [15]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [16]maintained by the GCC team. Last modified
- 2014-06-28[17].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.1/changes.html#4.1.2
- 3. http://gcc.gnu.org/gcc-4.1/changes.html
- 4. http://gcc.gnu.org/gcc-4.1/changes.html
- 5. http://gcc.gnu.org/gcc-4.1/buildstat.html
- 6. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 7. http://gcc.gnu.org/index.html
- 8. mailto:gcc at gcc.gnu.org
- 9. http://gcc.gnu.org/mirrors.html
- 10. http://gcc.gnu.org/svn.html
- 11. https://gcc.gnu.org/onlinedocs/
- 12. mailto:gcc-help at gcc.gnu.org
- 13. mailto:gcc at gcc.gnu.org
- 14. https://gcc.gnu.org/lists.html
- 15. http://www.fsf.org/
- 16. https://gcc.gnu.org/about.html
- 17. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.1/changes.html
- GCC 4.1 Release Series
- Changes, New Features, and Fixes
-
- The latest release in the 4.1 release series is [1]GCC 4.1.2.
-
-Caveats
-
-General Optimizer Improvements
-
- * GCC now has infrastructure for inter-procedural optimizations and
- the following inter-procedural optimizations are implemented:
- + Profile guided inlining. When doing profile feedback guided
- optimization, GCC can now use the profile to make better
- informed decisions on whether inlining of a function is
- profitable or not. This means that GCC will no longer inline
- functions at call sites that are not executed very often, and
- that functions at hot call sites are more likely to be
- inlined.
- A new parameter min-inline-recursive-probability is also now
- available to throttle recursive inlining of functions with
- small average recursive depths.
- + Discovery of pure and const functions, a form of side-effects
- analysis. While older GCC releases could also discover such
- special functions, the new IPA-based pass runs earlier so that
- the results are available to more optimizers. The pass is also
- simply more powerful than the old one.
- + Analysis of references to static variables and type escape
- analysis, also forms of side-effects analysis. The results of
- these passes allow the compiler to be less conservative about
- call-clobbered variables and references. This results in more
- redundant loads being eliminated and in making static
- variables candidates for register promotion.
- + Improvement of RTL-based alias analysis. The results of type
- escape analysis are fed to the RTL type-based alias analyzer,
- allowing it to disambiguate more memory references.
- + Interprocedural constant propagation and function versioning.
- This pass looks for functions that are always called with the
- same constant value for one or more of the function arguments,
- and propagates those constants into those functions.
- + GCC will now eliminate static variables whose usage was
- optimized out.
- + -fwhole-program --combine can now be used to make all
- functions in program static allowing whole program
- optimization. As an exception, the main function and all
- functions marked with the new externally_visible attribute are
- kept global so that programs can link with runtime libraries.
- * GCC can now do a form of partial dead code elimination (PDCE) that
- allows code motion of expressions to the paths where the result of
- the expression is actually needed. This is not always a win, so the
- pass has been limited to only consider profitable cases. Here is an
- example:
- int foo (int *, int *);
- int
- bar (int d)
- {
- int a, b, c;
- b = d + 1;
- c = d + 2;
- a = b + c;
- if (d)
- {
- foo (&b, &c);
- a = b + c;
- }
- printf ("%d\n", a);
- }
-
- The a = b + c can be sunk to right before the printf. Normal code
- sinking will not do this, it will sink the first one above into the
- else-branch of the conditional jump, which still gives you two
- copies of the code.
- * GCC now has a value range propagation pass. This allows the
- compiler to eliminate bounds checks and branches. The results of
- the pass can also be used to accurately compute branch
- probabilities.
- * The pass to convert PHI nodes to straight-line code (a form of
- if-conversion for GIMPLE) has been improved significantly. The two
- most significant improvements are an improved algorithm to
- determine the order in which the PHI nodes are considered, and an
- improvement that allow the pass to consider if-conversions of basic
- blocks with more than two predecessors.
- * Alias analysis improvements. GCC can now differentiate between
- different fields of structures in Tree-SSA's virtual operands form.
- This lets stores/loads from non-overlapping structure fields not
- conflict. A new algorithm to compute points-to sets was contributed
- that can allows GCC to see now that p->a and p->b, where p is a
- pointer to a structure, can never point to the same field.
- * Various enhancements to auto-vectorization:
- + Incrementally preserve SSA form when vectorizing.
- + Incrementally preserve loop-closed form when vectorizing.
- + Improvements to peeling for alignment: generate better code
- when the misalignment of an access is known at compile time,
- or when different accesses are known to have the same
- misalignment, even if the misalignment amount itself is
- unknown.
- + Consider dependence distance in the vectorizer.
- + Externalize generic parts of data reference analysis to make
- this analysis available to other passes.
- + Vectorization of conditional code.
- + Reduction support.
- * GCC can now partition functions in sections of hot and cold code.
- This can significantly improve performance due to better
- instruction cache locality. This feature works best together with
- profile feedback driven optimization.
- * A new pass to avoid saving of unneeded arguments to the stack in
- vararg functions if the compiler can prove that they will not be
- needed.
- * Transition of basic block profiling to tree level implementation
- has been completed. The new implementation should be considerably
- more reliable (hopefully avoiding profile mismatch errors when
- using -fprofile-use or -fbranch-probabilities) and can be used to
- drive higher level optimizations, such as inlining.
- The -ftree-based-profiling command-line option was removed and
- -fprofile-use now implies disabling old RTL level loop optimizer
- (-fno-loop-optimize). Speculative prefetching optimization
- (originally enabled by -fspeculative-prefetching) was removed.
-
-New Languages and Language specific improvements
-
- C and Objective-C
-
- * The old Bison-based C and Objective-C parser has been replaced by a
- new, faster hand-written recursive-descent parser.
-
- Ada
-
- * The build infrastructure for the Ada runtime library and tools has
- been changed to be better integrated with the rest of the build
- infrastructure of GCC. This should make doing cross builds of Ada a
- bit easier.
-
- C++
-
- * ARM-style name-injection of friend declarations is no longer the
- default. For example:
- struct S {
- friend void f();
- };
-
- void g() { f(); }
- will not be accepted; instead a declaration of f will need to be
- present outside of the scope of S. The new -ffriend-injection
- option will enable the old behavior.
- * The (undocumented) extension which permitted templates with default
- arguments to be bound to template template parameters with fewer
- parameters has been deprecated, and will be removed in the next
- major release of G++. For example:
- template <template <typename> class C>
- void f(C<double>) {}
-
- template <typename T, typename U = int>
- struct S {};
-
- template void f(S<double>);
-
- makes use of the deprecated extension. The reason this code is not
- valid ISO C++ is that S is a template with two parameters;
- therefore, it cannot be bound to C which has only one parameter.
-
- Runtime Library (libstdc++)
-
- * Optimization work:
- + A new implementation of std::search_n is provided, better
- performing in case of random access iterators.
- + Added further efficient specializations of istream functions,
- i.e., character array and string extractors.
- + Other smaller improvements throughout.
- * Policy-based associative containers, designed for high-performance,
- flexibility and semantic safety are delivered in ext/pb_assoc.
- * A versatile string class, __gnu_cxx::__versa_string, providing
- facilities conforming to the standard requirements for
- basic_string, is delivered in <ext/vstring.h>. In particular:
- + Two base classes are provided: the default one avoids
- reference counting and is optimized for short strings; the
- alternate one, still uses it while improving in a few low
- level areas (e.g., alignment). See vstring_fwd.h for some
- useful typedefs.
- + Various algorithms have been rewritten (e.g., replace), the
- code streamlined and simple optimizations added.
- + Option 3 of DR 431 is implemented for both available bases,
- thus improving the support for stateful allocators.
- * As usual, many bugs have been fixed (e.g., libstdc++/13583,
- libstdc++/23953) and LWG resolutions put into effect for the first
- time (e.g., DR 280, DR 464, N1780 recommendations for DR 233, TR1
- Issue 6.19). The implementation status of TR1 is now tracked in the
- docs in tr1.html.
-
- Objective-C++
-
- * A new language front end for Objective-C++ has been added. This
- language allows users to mix the object oriented features of
- Objective-C with those of C++.
-
- Java (GCJ)
-
- * Core library (libgcj) updates based on GNU Classpath 0.15 - 0.19
- features (plus some 0.20 bug-fixes)
- + Networking
- o The java.net.HttpURLConnection implementation no longer
- buffers the entire response body in memory. This means
- that response bodies larger than available memory can now
- be handled.
- + (N)IO
- o NIO FileChannel.map implementation, fast bulk put
- implementation for DirectByteBuffer (speeds up this
- method 10x).
- o FileChannel.lock() and FileChannel.force() implemented.
- + XML
- o gnu.xml fix for nodes created outside a namespace
- context.
- o Add support for output indenting and
- cdata-section-elements output instruction in
- xml.transform.
- o xml.xpath corrections for cases where elements/attributes
- might have been created in non-namespace-aware mode.
- Corrections to handling of XSL variables and minor
- conformance updates.
- + AWT
- o GNU JAWT implementation, the AWT Native Interface, which
- allows direct access to native screen resources from
- within a Canvas's paint method. GNU Classpath Examples
- comes with a Demo, see libjava/classpath/examples/README.
- o awt.datatransfer updated to 1.5 with support for
- FlavorEvents. The gtk+ awt peers now allow copy/paste of
- text, images, URIs/files and serialized objects with
- other applications and tracking clipboard change events
- with gtk+ 2.6 (for gtk+ 2.4 only text and serialized
- objects are supported). A GNU Classpath Examples
- datatransfer Demo was added to show the new
- functionality.
- o Split gtk+ awt peers event handling in two threads and
- improve gdk lock handling (solves several awt lock ups).
- o Speed up awt Image loading.
- o Better gtk+ scrollbar peer implementation when using gtk+
- >= 2.6.
- o Handle image loading errors correctly for gdkpixbuf and
- MediaTracker.
- o Better handle GDK lock. Properly prefix gtkpeer native
- functions (cp_gtk).
- o GdkGraphics2D has been updated to use Cairo 0.5.x or
- higher.
- o BufferedImage and GtkImage rewrites. All image drawing
- operations should now work correctly (flipping requires
- gtk+ >= 2.6)
- o Future Graphics2D, image and text work is documented at:
- [2]http://developer.classpath.org/mediation/ClasspathGrap
- hicsImagesText
- o When gtk+ 2.6 or higher is installed the default log
- handler will produce stack traces whenever a WARNING,
- CRITICAL or ERROR message is produced.
- + Free Swing
- o The RepaintManager has been reworked for more efficient
- painting, especially for large GUIs.
- o The layout manager OverlayLayout has been implemented,
- the BoxLayout has been rewritten to make use of the
- SizeRequirements utility class and caching for more
- efficient layout.
- o Improved accessibility support.
- o Significant progress has been made in the implementation
- of the javax.swing.plaf.metal package, with most UI
- delegates in a working state now. Please test this with
- your own applications and provide feedback that will help
- us to improve this package.
- o The GUI demo (gnu.classpath.examples.swing.Demo) has been
- extended to highlight various features in our Free Swing
- implementation. And it includes a look and feel switcher
- for Metal (default), Ocean and GNU themes.
- o The javax.swing.plaf.multi package is now implemented.
- o Editing and several key actions for JTree and JTable were
- implemented.
- o Lots of icons and look and feel improvements for Free
- Swing basic and metal themes were added. Try running the
- GNU Classpath Swing Demo in examples
- (gnu.classpath.examples.swing.Demo) with:
- -Dswing.defaultlaf=javax.swing.plaf.basic.BasicLookAndFee
- l or
- -Dswing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFee
- l
- o Start of styled text capabilites for java.swing.text.
- o DefaultMutableTreeNode pre-order, post-order, depth-first
- and breadth-first traversal enumerations implemented.
- o JInternalFrame colors and titlebar draw properly.
- o JTree is working up to par (icons, selection and keyboard
- traversal).
- o JMenus were made more compatible in visual and
- programmatic behavior.
- o JTable changeSelection and multiple selections
- implemented.
- o JButton and JToggleButton change states work properly
- now.
- o JFileChooser fixes.
- o revalidate() and repaint() fixes which make Free Swing
- much more responsive.
- o MetalIconFactory implemented.
- o Free Swing Top-Level Compatibility. JFrame, JDialog,
- JApplet, JInternalFrame, and JWindow are now 1.5
- compatible in the sense that you can call add() and
- setLayout() directly on them, which will have the same
- effect as calling getContentPane().add() and
- getContentPane().setLayout().
- o The JTree interface has been completed. JTrees now
- recognizes mouse clicks and selections work.
- o BoxLayout works properly now.
- o Fixed GrayFilter to actually work.
- o Metal SplitPane implemented.
- o Lots of Free Swing text and editor stuff work now.
- + Free RMI and Corba
- o Andrew Watson, Vice President and Technical Director of
- the Object Management Group, has officially assigned us
- 20 bit Vendor Minor Code Id: 0x47430 ("GC") that will
- mark remote classpath-specific system exceptions.
- Obtaining the VMCID means that GNU Classpath now is a
- recogniseable type of node in a highly interoperable
- CORBA world.
- o GNU Classpath now includes the first working draft to
- support the RMI over IIOP protocol. The current
- implementation is capable of remote invocations,
- transferring various Serializables and Externalizables
- via RMI-IIOP protocol. It can flatten graphs and, at
- least for the simple cases, is interoperable with 1.5
- JDKs.
- o org.omg.PortableInterceptor and related functionality in
- other packages is now implemented:
- # The sever and client interceptors work as required
- since 1.4.
- # The IOR interceptor works as needed for 1.5.
- o The org.omg.DynamicAny package is completed and passes
- the prepared tests.
- o The Portable Object Adapter should now support the output
- of the recent IDL to java compilers. These compilers now
- generate servants and not CORBA objects as before, making
- the output depend on the existing POA implementation.
- Completing POA means that such code can already be tried
- to run on Classpath. Our POA is tested for the following
- usager scenarios:
- # POA converts servant to the CORBA object.
- # Servant provides to the CORBA object.
- # POA activates new CORBA object with the given Object
- Id (byte array) that is later accessible for the
- servant.
- # During the first call, the ServantActivator provides
- servant for this and all subsequent calls on the
- current object.
- # During each call, the ServantLocator provides
- servant for this call only.
- # ServantLocator or ServantActivator forwards call to
- another server.
- # POA has a single servant, responsible for all
- objects.
- # POA has a default servant, but some objects are
- explicitly connected to they specific servants.
- The POA is verified using tests from the former
- cost.omg.org.
- o The CORBA implementation is now a working prototype that
- should support features up to 1.3 inclusive. We invite
- groups writing CORBA dependent applications to try
- Classpath implementation, reporting any possible bugs.
- The CORBA prototype is interoperable with Sun's
- implementation v 1.4, transferring object references,
- primitive types, narrow and wide strings, arrays,
- structures, trees, abstract interfaces and value types
- (feature of CORBA 2.3) between these two platforms.
- Remote exceptions are transferred and handled correctly.
- The stringified object references (IORs) from various
- sources are parsed as required. The transient (for
- current session) and permanent (till jre restart)
- redirections work. Both Little and Big Endian encoded
- messages are accepted. The implementation is verified
- using tests from the former cost.omg.org. The current
- release includes working examples (see the examples
- directory), demonstrating the client-server
- communication, using either CORBA Request or IDL-based
- stub (usually generated by a IDL to java compiler). These
- examples also show how to use the Classpath CORBA naming
- service. The IDL to java compiler is not yet written, but
- as our library must be compatible, it naturally accepts
- the output of other idlj implementations.
- + Misc
- o Updated TimeZone data against Olson tzdata2005l.
- o Make zip and jar packages UTF-8 clean.
- o "native" code builds and compiles (warning free) on
- Darwin and Solaris.
- o java.util.logging.FileHandler now rotates files.
- o Start of a generic JDWP framework in gnu/classpath/jdwp.
- This is unfinished, but feedback (at classpath at gnu.org)
- from runtime hackers is greatly appreciated. Although
- most of the work is currently being done around gcj/gij
- we want this framework to be as VM neutral as possible.
- Early design is described in:
- [3]https://gcc.gnu.org/ml/java/2005-05/msg00260.html
- o QT4 AWT peers, enable by giving configure
- --enable-qt-peer. Included, but not ready for production
- yet. They are explicitly disabled and not supported. But
- if you want to help with the development of these new
- features we are interested in feedback. You will have to
- explicitly enable them to try them out (and they will
- most likely contain bugs).
- o Documentation fixes all over the place. See
- [4]http://developer.classpath.org/doc/
-
-New Targets and Target Specific Improvements
-
- IA-32/x86-64
-
- * The x86-64 medium model (that allows building applications whose
- data segment exceeds 4GB) was redesigned to match latest ABI draft.
- New implementation split large datastructures into separate segment
- improving performance of accesses to small datastructures and also
- allows linking of small model libraries into medium model programs
- as long as the libraries are not accessing the large datastructures
- directly. Medium model is also supported in position independent
- code now.
- The ABI change results in partial incompatibility among medium
- model objects. Linking medium model libraries (or objects) compiled
- with new compiler into medium model program compiled with older
- will likely result in exceeding ranges of relocations.
- Binutils 2.16.91 or newer are required for compiling medium model
- now.
-
- RS6000 (POWER/PowerPC)
-
- * The AltiVec vector primitives in <altivec.h> are now implemented in
- a way that puts a smaller burden on the preprocessor, instead
- processing the "overloading" in the front ends. This should benefit
- compilation speed on AltiVec vector code.
- * AltiVec initializers now are generated more efficiently.
- * The popcountb instruction available on POWER5 now is generated.
- * The floating point round to integer instructions available on
- POWER5+ now is generated.
- * Floating point divides can be synthesized using the floating point
- reciprocal estimate instructions.
- * Double precision floating point constants are initialized as single
- precision values if they can be represented exactly.
-
- S/390, zSeries and System z9
-
- * Support for the IBM System z9 109 processor has been added. When
- using the -march=z9-109 option, the compiler will generate code
- making use of instructions provided by the extended immediate
- facility.
- * Support for 128-bit IEEE floating point has been added. When using
- the -mlong-double-128 option, the compiler will map the long double
- data type to 128-bit IEEE floating point. Using this option
- constitutes an ABI change, and requires glibc support.
- * Various changes to improve performance of generated code have been
- implemented, including:
- + In functions that do not require a literal pool, register %r13
- (which is traditionally reserved as literal pool pointer), can
- now be freely used for other purposes by the compiler.
- + More precise tracking of register use allows the compiler to
- generate more efficient function prolog and epilog code in
- certain cases.
- + The SEARCH STRING, COMPARE LOGICAL STRING, and MOVE STRING
- instructions are now used to implement C string functions.
- + The MOVE CHARACTER instruction with single byte overlap is now
- used to implement the memset function with non-zero fill byte.
- + The LOAD ZERO instructions are now used where appropriate.
- + The INSERT CHARACTERS UNDER MASK, STORE CHARACTERS UNDER MASK,
- and INSERT IMMEDIATE instructions are now used more frequently
- to optimize bitfield operations.
- + The BRANCH ON COUNT instruction is now used more frequently.
- In particular, the fact that a loop contains a subroutine call
- no longer prevents the compiler from using this instruction.
- + The compiler is now aware that all shift and rotate
- instructions implicitly truncate the shift count to six bits.
- * Back-end support for the following generic features has been
- implemented:
- + The full set of [5]built-in functions for atomic memory
- access.
- + The -fstack-protector feature.
- + The optimization pass avoiding unnecessary stores of incoming
- argument registers in functions with variable argument list.
-
- SPARC
-
- * The default code model in 64-bit mode has been changed from
- Medium/Anywhere to Medium/Middle on Solaris.
- * TLS support is disabled by default on Solaris prior to release 10.
- It can be enabled on TLS-capable Solaris 9 versions (4/04 release
- and later) by specifying --enable-tls at configure time.
-
- MorphoSys
-
- * Support has been added for this new architecture.
-
-Obsolete Systems
-
-Documentation improvements
-
-Other significant improvements
-
- * GCC can now emit code for protecting applications from
- stack-smashing attacks. The protection is realized by buffer
- overflow detection and reordering of stack variables to avoid
- pointer corruption.
- * Some built-in functions have been fortified to protect them against
- various buffer overflow (and format string) vulnerabilities.
- Compared to the mudflap bounds checking feature, the safe builtins
- have far smaller overhead. This means that programs built using
- safe builtins should not experience any measurable slowdown.
-
-GCC 4.1.2
-
- This is the [6]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.1.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- When generating code for a shared library, GCC now recognizes that
- global functions may be replaced when the program runs. Therefore, it
- is now more conservative in deducing information from the bodies of
- functions. For example, in this example:
- void f() {}
- void g() {
- try { f(); }
- catch (...) {
- cout << "Exception";
- }
- }
-
- G++ would previously have optimized away the catch clause, since it
- would have concluded that f cannot throw exceptions. Because users may
- replace f with another function in the main body of the program, this
- optimization is unsafe, and is no longer performed. If you wish G++ to
- continue to optimize as before, you must add a throw() clause to the
- declaration of f to make clear that it does not throw exceptions.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [7]GCC manuals. If that fails, the
- [8]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [9]gcc at gcc.gnu.org. All of [10]our lists have public
- archives.
-
- Copyright (C) [11]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [12]maintained by the GCC team. Last modified
- 2014-06-28[13].
-
-References
-
- 1. http://gcc.gnu.org/gcc-4.1/changes.html#4.1.2
- 2. http://developer.classpath.org/mediation/ClasspathGraphicsImagesText
- 3. https://gcc.gnu.org/ml/java/2005-05/msg00260.html
- 4. http://developer.classpath.org/doc/
- 5. https://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html
- 6. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.1.2
- 7. https://gcc.gnu.org/onlinedocs/
- 8. mailto:gcc-help at gcc.gnu.org
- 9. mailto:gcc at gcc.gnu.org
- 10. https://gcc.gnu.org/lists.html
- 11. http://www.fsf.org/
- 12. https://gcc.gnu.org/about.html
- 13. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.0/index.html
- GCC 4.0 Release Series
-
- January 31, 2007
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 4.0.4.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 4.0.3 relative to previous releases of GCC.
-
-Release History
-
- GCC 4.0.4
- January 31, 2007 ([2]changes)
-
- GCC 4.0.3
- March 10, 2006 ([3]changes)
-
- GCC 4.0.2
- September 28, 2005 ([4]changes)
-
- GCC 4.0.1
- July 7, 2005 ([5]changes)
-
- GCC 4.0.0
- April 20, 2005 ([6]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [7]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [8]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [9]GCC project
- web site or contact the [10]GCC development mailing list.
-
- To obtain GCC please use [11]our mirror sites, or [12]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [13]GCC manuals. If that fails, the
- [14]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [15]gcc at gcc.gnu.org. All of [16]our lists have public
- archives.
-
- Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [18]maintained by the GCC team. Last modified
- 2014-06-28[19].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.4
- 3. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.3
- 4. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.2
- 5. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.1
- 6. http://gcc.gnu.org/gcc-4.0/changes.html
- 7. http://gcc.gnu.org/gcc-4.0/buildstat.html
- 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 9. http://gcc.gnu.org/index.html
- 10. mailto:gcc at gcc.gnu.org
- 11. http://gcc.gnu.org/mirrors.html
- 12. http://gcc.gnu.org/svn.html
- 13. https://gcc.gnu.org/onlinedocs/
- 14. mailto:gcc-help at gcc.gnu.org
- 15. mailto:gcc at gcc.gnu.org
- 16. https://gcc.gnu.org/lists.html
- 17. http://www.fsf.org/
- 18. https://gcc.gnu.org/about.html
- 19. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-4.0/changes.html
- GCC 4.0 Release Series
- Changes, New Features, and Fixes
-
- The latest release in the 4.0 release series is [1]GCC 4.0.4.
-
-Caveats
-
- * GCC now generates location lists by default when compiling with
- debug info and optimization.
- + GDB 6.0 and older crashes when it sees location lists. GDB 6.1
- or later is needed to debug binaries containing location
- lists.
- + When you are trying to view a value of a variable in a part of
- a function where it has no location (for example when the
- variable is no longer used and thus its location was used for
- something else) GDB will say that it is not available.
- You can disable generating location lists by -fno-var-tracking.
- * GCC no longer accepts the -fwritable-strings option. Use named
- character arrays when you need a writable string.
- * The options -freduce-all-givs and -fmove-all-movables have been
- discontinued. They were used to circumvent a shortcoming in the
- heuristics of the old loop optimization code with respect to common
- Fortran constructs. The new (tree) loop optimizer works differently
- and doesn't need those work-arounds.
- * The graph-coloring register allocator, formerly enabled by the
- option -fnew-ra, has been discontinued.
- * -I- has been deprecated. -iquote is meant to replace the need for
- this option.
- * The MIPS -membedded-pic and -mrnames options have been removed.
- * All MIPS targets now require the GNU assembler. In particular, IRIX
- configurations can no longer use the MIPSpro assemblers, although
- they do still support the MIPSpro linkers.
- * The SPARC option -mflat has been removed.
- * English-language diagnostic messages will now use Unicode quotation
- marks in UTF-8 locales. (Non-English messages already used the
- quotes appropriate for the language in previous releases.) If your
- terminal does not support UTF-8 but you are using a UTF-8 locale
- (such locales are the default on many GNU/Linux systems) then you
- should set LC_CTYPE=C in the environment to disable that locale.
- Programs that parse diagnostics and expect plain ASCII
- English-language messages should set LC_ALL=C. See [2]Markus Kuhn's
- explanation of Unicode quotation marks for more information.
- * The specs file is no longer installed on most platforms. Most users
- will be totally unaffected. However, if you are accustomed to
- editing the specs file yourself, you will now have to use the
- -dumpspecs option to generate the specs file, and then edit the
- resulting file.
-
-General Optimizer Improvements
-
- * The [3]tree ssa branch has been merged. This merge has brought in a
- completely new optimization framework based on a higher level
- intermediate representation than the existing RTL representation.
- Numerous new code transformations based on the new framework are
- available in GCC 4.0, including:
- + Scalar replacement of aggregates
- + Constant propagation
- + Value range propagation
- + Partial redundancy elimination
- + Load and store motion
- + Strength reduction
- + Dead store elimination
- + Dead and unreachable code elimination
- + [4]Autovectorization
- + Loop interchange
- + Tail recursion by accumulation
- Many of these passes outperform their counterparts from previous
- GCC releases.
- * [5]Swing Modulo Scheduling (SMS). An RTL level instruction
- scheduling optimization intended for loops that perform heavy
- computations.
-
-New Languages and Language specific improvements
-
- C family
-
- * The sentinel attribute has been added to GCC. This function
- attribute allows GCC to warn when variadic functions such as execl
- are not NULL terminated. See the GCC manual for a complete
- description of its behavior.
- * Given __attribute__((alias("target"))) it is now an error if target
- is not a symbol, defined in the same translation unit. This also
- applies to aliases created by #pragma weak alias=target. This is
- because it's meaningless to define an alias to an undefined symbol.
- On Solaris, the native assembler would have caught this error, but
- GNU as does not.
-
- C and Objective-C
-
- * The -Wstrict-aliasing=2 option has been added. This warning catches
- all unsafe cases, but it may also give a warning for some cases
- that are safe.
- * The cast-as-lvalue, conditional-expression-as-lvalue and
- compound-expression-as-lvalue extensions, which were deprecated in
- 3.3.4 and 3.4, have been removed.
- * The -fwritable-strings option, which was deprecated in 3.4, has
- been removed.
- * #pragma pack() semantics have been brought closer to those used by
- other compilers. This also applies to C++.
- * Taking the address of a variable with register storage is invalid
- in C. GCC now issues an error instead of a warning.
- * Arrays of incomplete element type are invalid in C. GCC now issues
- an error for such arrays. Declarations such as extern struct s x[];
- (where struct s has not been defined) can be moved after the
- definition of struct s. Function parameters declared as arrays of
- incomplete type can instead be declared as pointers.
-
- C++
-
- * When compiling without optimizations (-O0), the C++ frontend is
- much faster than in any previous versions of GCC. Independent
- testers have measured speed-ups up to 25% in real-world production
- code, compared to the 3.4 family (which was already the fastest
- version to date). Upgrading from older versions might show even
- bigger improvements.
- * ELF visibility attributes can now be applied to a class type, so
- that it affects every member function of a class at once, without
- having to specify each individually:
-class __attribute__ ((visibility("hidden"))) Foo
-{
- int foo1();
- void foo2();
-};
- The syntax is deliberately similar to the __declspec() system used
- by Microsoft Windows based compilers, allowing cross-platform
- projects to easily reuse their existing macro system for denoting
- exports and imports. By explicitly marking internal classes never
- used outside a binary as hidden, one can completely avoid PLT
- indirection overheads during their usage by the compiler. You can
- find out more about the advantages of this at
- [6]http://www.akkadia.org/drepper/dsohowto.pdf
- * The -fvisibility-inlines-hidden option has been added which marks
- all inlineable functions as having hidden ELF visibility, thus
- removing their symbol and typeinfo from the exported symbol table
- of the output ELF binary. Using this option can reduce the exported
- symbol count of template-heavy code by up to 40% with no code
- change at all, thus notably improving link and load times for the
- binary as well as a reduction in size of up to 10%. Also, check the
- new [7]-fvisibility option.
- * The compiler now uses the library interface specified by the [8]C++
- ABI for thread-safe initialization of function-scope static
- variables. Most users should leave this alone, but embedded
- programmers may want to disable this by specifying
- -fno-threadsafe-statics for a small savings in code size.
- * Taking the address of an explicit register variable is no longer
- supported. Note that C++ allows taking the address of variables
- with register storage so this will continue to compile with a
- warning. For example, assuming that r0 is a machine register:
-register int foo asm ("r0");
-register int bar;
-&foo; // error, no longer accepted
-&bar; // OK, with a warning
- * G++ has an undocumented extension to virtual function covariancy
- rules that allowed the overrider to return a type that was
- implicitly convertable to the overridden function's return type.
- For instance a function returning void * could be overridden by a
- function returning T *. This is now deprecated and will be removed
- in a future release.
- * The G++ minimum and maximum operators (<? and >?) and their
- compound forms (<?=) and >?=) have been deprecated and will be
- removed in a future version. Code using these operators should be
- modified to use std::min and std::max instead.
- * Declaration of nested classes of class templates as friends are
- supported:
-template <typename T> struct A {
- class B {};
-};
-class C {
- template <typename T> friend class A<T>::B;
-};
- This complements the feature member functions of class templates as
- friends introduced in GCC 3.4.0.
- * When declaring a friend class using an unqualified name, classes
- outside the innermost non-class scope are not searched:
-class A;
-namespace N {
- class B {
- friend class A; // Refer to N::A which has not been declared yet
- // because name outside namespace N are not searched
- friend class ::A; // Refer to ::A
- };
-}
- Hiding the friend name until declaration is still not implemented.
- * Friends of classes defined outside their namespace are correctly
- handled:
-namespace N {
- class A;
-}
-class N::A {
- friend class B; // Refer to N::B in GCC 4.0.0
- // but ::B in earlier versions of GCC
-};
-
- Runtime Library (libstdc++)
-
- * Optimization work:
- + Added efficient specializations of istream functions for char
- and wchar_t.
- + Further performance tuning of strings, in particular wrt
- single-char append and getline.
- + iter_swap - and therefore most of the mutating algorithms -
- now makes an unqualified call to swap when the value_type of
- the two iterators is the same.
- * A large subset of the features in Technical Report 1 (TR1 for
- short) is experimentally delivered (i.e., no guarantees about the
- implementation are provided. In particular it is not promised that
- the library will remain link-compatible when code using TR1 is
- used):
- + General utilities such as reference_wrapper and shared_ptr.
- + Function objects, i.e., result_of, mem_fn, bind, function.
- + Support for metaprogramming.
- + New containers such as tuple, array, unordered_set,
- unordered_map, unordered_multiset, unordered_multimap.
- * As usual, many bugs have been fixed and LWG resolutions implemented
- for the first time (e.g., DR 409).
-
- Java
-
- * In order to prevent naming conflicts with other implementations of
- these tools, some GCJ binaries have been renamed:
- + rmic is now grmic,
- + rmiregistry is now grmiregistry, and
- + jar is now fastjar.
- In particular, these names were problematic for the jpackage.org
- packaging conventions which install symlinks in /usr/bin that point
- to the preferred versions of these tools.
- * The -findirect-dispatch argument to the compiler now works and
- generates code following a new "binary compatibility" ABI. Code
- compiled this way follows the binary compatibility rules of the
- Java Language Specification.
- * libgcj now has support for using GCJ as a JIT, using the
- gnu.gcj.jit family of system properties.
- * libgcj can now find a shared library corresponding to the bytecode
- representation of a class. See the documentation for the new
- gcj-dbtool program, and the new gnu.gcj.precompiled.db.path system
- property.
- * There have been many improvements to the class library. Here are
- some highlights:
- + Much more of AWT and Swing exist.
- + Many new packages and classes were added, including
- java.util.regex, java.net.URI, javax.crypto,
- javax.crypto.interfaces, javax.crypto.spec, javax.net,
- javax.net.ssl, javax.security.auth,
- javax.security.auth.callback, javax.security.auth.login,
- javax.security.auth.x500, javax.security.sasl, org.ietf.jgss,
- javax.imageio, javax.imageio.event, javax.imageio.spi,
- javax.print, javax.print.attribute,
- javax.print.attribute.standard, javax.print.event, and
- javax.xml
- + Updated SAX and DOM, and imported GNU JAXP
-
- Fortran
-
- * A new [9]Fortran front end has replaced the aging GNU Fortran 77
- front end. The new front end supports Fortran 90 and Fortran 95. It
- may not yet be as stable as the old Fortran front end.
-
- Ada
-
- * Ada (with tasking and Zero Cost Exceptions) is now available on
- many more targets, including but not limited to: alpha-linux,
- hppa-hpux, hppa-linux, powerpc-darwin, powerpc-linux, s390-linux,
- s390x-linux, sparc-linux.
- * Some of the new Ada 2005 features are now implemented like
- Wide_Wide_Character and Ada.Containers.
- * Many bugs have been fixed, tools and documentation improved.
- * To compile Ada from the sources, install an older working Ada
- compiler and then use --enable-languages=ada at configuration time,
- since the Ada frontend is not currently activated by default. See
- the [10]Installing GCC for details.
-
-New Targets and Target Specific Improvements
-
- H8/300
-
- * The frame layout has changed. In the new layout, the prologue of a
- function first saves registers and then allocate space for locals,
- resulting in an 1% improvement on code size.
-
- IA-32/x86-64 (AMD64)
-
- * The acos, asin, drem, exp10, exp2, expm1, fmod, ilogb, log10,
- log1p, log2, logb and tan mathematical builtins (and their float
- and long double variants) are now implemented as inline x87
- intrinsics when using -ffast-math.
- * The ceil, floor, nearbyint, rint and trunc mathematical builtins
- (and their float and long double variants) are now implemented as
- inline x87 intrinsics when using -ffast-math.
- * The x87's fsincos instruction is now used automatically with
- -ffast-math when calculating both the sin and cos of the same
- argument.
- * Instruction selection for multiplication and division by constants
- has been improved.
-
- IA-64
-
- * Floating point division, integer division and sqrt are now inlined,
- resulting in significant performance improvements on some codes.
-
- MIPS
-
- * Division by zero checks now use conditional traps if the target
- processor supports them. This decreases code size by one word per
- division operation. The old behavior (branch and break) can be
- obtained either at configure time by passing --with-divide=breaks
- to configure or at runtime by passing -mdivide-breaks to GCC.
- * Support for MIPS64 paired-single instructions has been added. It is
- enabled by -mpaired-single and can be accessed using both the
- target-independent vector extensions and new MIPS-specific built-in
- functions.
- * Support for the MIPS-3D ASE has been added. It is enabled by
- -mips3d and provides new MIPS-3D-specific built-in functions.
- * The -mexplicit-relocs option now supports static n64 code (as is
- used, for example, in 64-bit linux kernels). -mexplicit-relocs
- should now be feature-complete and is enabled by default when GCC
- is configured to use a compatible assembler.
- * Support for the NEC VR4130 series has been added. This support
- includes the use of VR-specific instructions and a new VR4130
- scheduler. Full VR4130 support can be selected with -march=vr4130
- while code for any ISA can be tuned for the VR4130 using
- -mtune=vr4130. There is also a new -mvr4130-align option that
- produces better schedules at the cost of increased code size.
- * Support for the Broadcom SB-1 has been extended. There is now an
- SB-1 scheduler as well as support for the SB-1-specific
- paired-single instructions. Full SB-1 support can be selected with
- -march=sb1 while code for any ISA can be optimized for the SB-1
- using -mtune=sb1.
- * The compiler can now work around errata in R4000, R4400, VR4120 and
- VR4130 processors. These workarounds are enabled by -mfix-r4000,
- -mfix-r4400, -mfix-vr4120 and -mfix-vr4130 respectively. The VR4120
- and VR4130 workarounds need binutils 2.16 or above.
- * IRIX shared libraries are now installed into the standard library
- directories: o32 libraries go into lib/, n32 libraries go into
- lib32/ and n64 libraries go into lib64/.
- * The compiler supports a new -msym32 option. It can be used to
- optimize n64 code in which all symbols are known to have 32-bit
- values.
-
- S/390 and zSeries
-
- * New command-line options help to generate code intended to run in
- an environment where stack space is restricted, e.g. Linux kernel
- code:
- + -mwarn-framesize and -mwarn-dynamicstack trigger compile-time
- warnings for single functions that require large or dynamic
- stack frames.
- + -mstack-size and -mstack-guard generate code that checks for
- stack overflow at run time.
- + -mpacked-stack generates code that reduces the stack frame
- size of many functions by reusing unneeded parts of the stack
- bias area.
- * The -msoft-float option now ensures that generated code never
- accesses floating point registers.
- * The s390x-ibm-tpf target now fully supports C++, including
- exceptions and threads.
- * Various changes to improve performance of the generated code have
- been implemented, including:
- + GCC now uses sibling calls where possible.
- + Condition code handling has been optimized, allowing GCC to
- omit redundant comparisons in certain cases.
- + The cost function guiding many optimizations has been refined
- to more accurately represent the z900 and z990 processors.
- + The ADD LOGICAL WITH CARRY and SUBTRACT LOGICAL WITH BORROW
- instructions are now used to avoid conditional branches in
- certain cases.
- + The back end now uses the LEGITIMIZE_RELOAD_ADDRESS feature to
- optimize address arithmetic required to access large stack
- frames.
- + GCC now makes more efficient use of memory-to-memory type
- instructions (MVC, CLC, ...).
- + More precise tracking of special register use allows better
- instruction scheduling, in particular of the function prologue
- and epilogue sequences.
- + The Java front end now generates inline code to implement
- integer division, instead of calling library routines.
-
- SPARC
-
- * The options -mv8, -msparclite, -mcypress, -msupersparc, -mf930 and
- -mf934 have been removed. They have been replaced with -mcpu=xxx.
- * The internal model used to estimate the relative cost of each
- instruction has been updated. It is expected to give better results
- on recent UltraSPARC processors.
- * Code generation for function prologues and epilogues has been
- improved, resulting in better scheduling and allowing multiple exit
- points in functions.
- * Support for Sun's Visual Instruction Set (VIS) has been enhanced.
- It is enabled by -mvis and provides new built-in functions for VIS
- instructions on UltraSPARC processors.
- * The option -mapp-regs has been turned on by default on Solaris too.
-
- NetWare
-
- * Novell NetWare (on ix86, no other hardware platform was ever really
- supported by this OS) has been re-enabled and the ABI supported by
- GCC has been brought into sync with that of MetroWerks CodeWarrior
- (the ABI previously supported was that of some Unix systems, which
- NetWare never tried to support).
-
-Obsolete Systems
-
- Support for a number of older systems has been declared obsolete in GCC
- 4.0. Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
-
- All GCC ports for the following processor architectures have been
- declared obsolete:
- * Intel i860
- * Ubicom IP2022
- * National Semiconductor NS32K
- * Texas Instruments TMS320C[34]x
-
- Also, those for some individual systems have been obsoleted:
- * SPARC family
- + SPARClite-based systems (sparclite-*-coff, sparclite-*-elf,
- sparc86x-*-elf)
- + OpenBSD 32-bit (sparc-*-openbsd*)
-
-Documentation improvements
-
-Other significant improvements
-
- * Location lists are now generated by default when compiling with
- debug info and optimization. Location lists provide more accurate
- debug info about locations of variables and they allow debugging
- code compiled with -fomit-frame-pointer.
- * The -fvisibility option has been added which allows the default ELF
- visibility of all symbols to be set per compilation and the new
- #pragma GCC visibility preprocessor command allows the setting of
- default ELF visibility for a region of code. Using
- -fvisibility=hidden especially in combination with the new
- -fvisibility-inlines-hidden can yield substantial improvements in
- output binary quality including avoiding PLT indirection overheads,
- reduction of the exported symbol count by up to 60% (with resultant
- improvements to link and load times), better scope for the
- optimizer to improve code and up to a 20% reduction in binary size.
- Using these options correctly yields a binary with a similar symbol
- count to a Windows DLL.
- Perhaps more importantly, this new feature finally allows (with
- careful planning) complete avoidance of symbol clashes when
- manually loading shared objects with RTLD_GLOBAL, thus finally
- solving problems many projects such as python were forced to use
- RTLD_LOCAL for (with its resulting issues for C++ correctness). You
- can find more information about using these options at
- [11]https://gcc.gnu.org/wiki/Visibility.
- __________________________________________________________________
-
-GCC 4.0.1
-
- This is the [12]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.0.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-GCC 4.0.2
-
- This is the [13]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.0.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Unfortunately, due to a release engineering failure, this release has a
- regression on Solaris that will affect some C++ programs. We suggest
- that Solaris users apply a [14]patch that corrects the problem. Users
- who do not wish to apply the patch should explicitly link C++ programs
- with the -pthreads option, even if they do not use threads. This
- problem has been corrected in the current 4.0 branch sources and will
- not be present in GCC 4.0.3.
-
-GCC 4.0.3
-
- Starting with this release, the function getcontext is recognized by
- the compiler as having the same semantics as the setjmp function. In
- particular, the compiler will ensure that all registers are dead before
- calling such a function and will emit a warning about the variables
- that may be clobbered after the second return from the function.
-
-GCC 4.0.4
-
- This is the [15]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 4.0.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- The 4.0.4 release is provided for those that require a high degree of
- binary compatibility with previous 4.0.x releases. For most users, the
- GCC team recommends that version 4.1.1 or later be used instead."
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [16]GCC manuals. If that fails, the
- [17]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [18]gcc at gcc.gnu.org. All of [19]our lists have public
- archives.
-
- Copyright (C) [20]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [21]maintained by the GCC team. Last modified
- 2014-06-28[22].
-
-References
-
- 1. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.4
- 2. http://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html
- 3. http://gcc.gnu.org/projects/tree-ssa/
- 4. http://gcc.gnu.org/projects/tree-ssa/vectorization.html
- 5. http://gcc.gnu.org/news/sms.html
- 6. http://www.akkadia.org/drepper/dsohowto.pdf
- 7. http://gcc.gnu.org/gcc-4.0/changes.html#visibility
- 8. http://mentorembedded.github.com/cxx-abi/
- 9. http://gcc.gnu.org/fortran/
- 10. https://gcc.gnu.org/install/
- 11. https://gcc.gnu.org/wiki/Visibility
- 12. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.0.1
- 13. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.0.2
- 14. https://gcc.gnu.org/ml/gcc-cvs/2005-09/msg00984.html
- 15. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.0.4
- 16. https://gcc.gnu.org/onlinedocs/
- 17. mailto:gcc-help at gcc.gnu.org
- 18. mailto:gcc at gcc.gnu.org
- 19. https://gcc.gnu.org/lists.html
- 20. http://www.fsf.org/
- 21. https://gcc.gnu.org/about.html
- 22. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.4/index.html
- GCC 3.4 Release Series
-
- May 26, 2006
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 3.4.6.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 3.4.4 relative to previous releases of GCC. This is the last of the
- 3.4.x series.
-
- The GCC 3.4 release series includes numerous [2]new features,
- improvements, bug fixes, and other changes, thanks to an [3]amazing
- group of volunteers.
-
-Release History
-
- GCC 3.4.6
- March 6, 2006 ([4]changes)
-
- GCC 3.4.5
- November 30, 2005 ([5]changes)
-
- GCC 3.4.4
- May 18, 2005 ([6]changes)
-
- GCC 3.4.3
- November 4, 2004 ([7]changes)
-
- GCC 3.4.2
- September 6, 2004 ([8]changes)
-
- GCC 3.4.1
- July 1, 2004 ([9]changes)
-
- GCC 3.4.0
- April 18, 2004 ([10]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [11]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [12]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [13]GCC
- project web site or contact the [14]GCC development mailing list.
-
- To obtain GCC please use [15]our mirror sites, or [16]our SVN server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [17]GCC manuals. If that fails, the
- [18]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [19]gcc at gcc.gnu.org. All of [20]our lists have public
- archives.
-
- Copyright (C) [21]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [22]maintained by the GCC team. Last modified
- 2014-06-28[23].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-3.4/changes.html
- 3. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 4. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.6
- 5. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.5
- 6. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.4
- 7. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.3
- 8. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.2
- 9. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.1
- 10. http://gcc.gnu.org/gcc-3.4/changes.html
- 11. http://gcc.gnu.org/gcc-3.4/buildstat.html
- 12. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 13. http://gcc.gnu.org/index.html
- 14. mailto:gcc at gcc.gnu.org
- 15. http://gcc.gnu.org/mirrors.html
- 16. http://gcc.gnu.org/svn.html
- 17. https://gcc.gnu.org/onlinedocs/
- 18. mailto:gcc-help at gcc.gnu.org
- 19. mailto:gcc at gcc.gnu.org
- 20. https://gcc.gnu.org/lists.html
- 21. http://www.fsf.org/
- 22. https://gcc.gnu.org/about.html
- 23. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.4/changes.html
- GCC 3.4 Release Series
- Changes, New Features, and Fixes
-
- The final release in the 3.4 release series is [1]GCC 3.4.6. The series
- is now closed.
-
- GCC 3.4 has [2]many improvements in the C++ frontend. Before reporting
- a bug, please make sure it's really GCC, and not your code, that is
- broken.
-
-Caveats
-
- * GNU Make is now required to build GCC.
- * With -nostdinc the preprocessor used to ignore both standard
- include paths and include paths contained in environment variables.
- It was neither documented nor intended that environment variable
- paths be ignored, so this has been corrected.
- * GCC no longer accepts the options -fvolatile, -fvolatile-global and
- -fvolatile-static. It is unlikely that they worked correctly in any
- 3.x release.
- * GCC no longer ships <varargs.h>. Use <stdarg.h> instead.
- * Support for all the systems [3]obsoleted in GCC 3.3 has been
- removed from GCC 3.4. See below for a [4]list of systems which are
- obsoleted in this release.
- * GCC now requires an ISO C90 (ANSI C89) C compiler to build. K&R C
- compilers will not work.
- * The implementation of the [5]MIPS ABIs has changed. As a result,
- the code generated for certain MIPS targets will not be binary
- compatible with earlier releases.
- * In previous releases, the MIPS port had a fake "hilo" register with
- the user-visible name accum. This register has been removed.
- * The implementation of the [6]SPARC ABIs has changed. As a result,
- the code generated will not be binary compatible with earlier
- releases in certain cases.
- * The configure option --enable-threads=pthreads has been removed;
- use --enable-threads=posix instead, which should have the same
- effect.
- * Code size estimates used by inlining heuristics for C, Objective-C,
- C++ and Java have been redesigned significantly. As a result the
- parameters of -finline-insns, --param max-inline-insns-single and
- --param max-inline-insns-auto need to be reconsidered.
- * --param max-inline-slope and --param min-inline-insns have been
- removed; they are not needed for the new bottom-up inlining
- heuristics.
- * The new unit-at-a-time compilation scheme has several compatibility
- issues:
- + The order in which functions, variables, and top-level asm
- statements are emitted may have changed. Code relying on some
- particular ordering needs to be updated. The majority of such
- top-level asm statements can be replaced by section
- attributes.
- + Unreferenced static variables and functions are removed. This
- may result in undefined references when an asm statement
- refers to the variable/function directly. In that case either
- the variable/function shall be listed in asm statement operand
- or in the case of top-level asm statements the attribute used
- shall be used to force function/variable to be always output
- and considered as a possibly used by unknown code.
- For variables the attribute is accepted only by GCC 3.4 and
- newer, while for earlier versions it is sufficient to use
- unused to silence warnings about the variables not being
- referenced. To keep code portable across different GCC
- versions, you can use appropriate preprocessor conditionals.
- + Static functions now can use non-standard passing conventions
- that may break asm statements calling functions directly.
- Again the attribute used shall be used to prevent this
- behavior.
- As a temporary workaround, -fno-unit-at-a-time can be used, but
- this scheme may not be supported by future releases of GCC.
- * GCC 3.4 automatically places zero-initialized variables in the .bss
- section on some operating systems. Versions of GNU Emacs up to (and
- including) 21.3 will not work correctly when using this
- optimization; you can use -fno-zero-initialized-in-bss to disable
- it.
- * If GCC 3.4 is configured with --enable-threads=posix (the default
- on most targets that support pthreads) then _REENTRANT will be
- defined unconditionally by some libstdc++ headers. C++ code which
- relies on that macro to detect whether multi-threaded code is being
- compiled might change in meaning, possibly resulting in linker
- errors for single-threaded programs. Affected users of [7]Boost
- should compile single-threaded code with -DBOOST_DISABLE_THREADS.
- See Bugzilla for [8]more information.
-
-General Optimizer Improvements
-
- * Usability of the profile feedback and coverage testing has been
- improved.
- + Performance of profiled programs has been improved by faster
- profile merging code.
- + Better use of the profile feedback for optimization (loop
- unrolling and loop peeling).
- + File locking support allowing fork() calls and parallel runs
- of profiled programs.
- + Coverage file format has been redesigned.
- + gcov coverage tool has been improved.
- + make profiledbootstrap available to build a faster compiler.
- Experiments made on i386 hardware showed an 11% speedup on -O0
- and a 7.5% speedup on -O2 compilation of a [9]large C++
- testcase.
- + New value profiling pass enabled via -fprofile-values
- + New value profile transformations pass enabled via -fvpt aims
- to optimize some code sequences by exploiting knowledge about
- value ranges or other properties of the operands. At the
- moment a conversion of expensive divisions into cheaper
- operations has been implemented.
- + New -fprofile-generate and -fprofile-use command-line options
- to simplify the use of profile feedback.
- * A new unit-at-a-time compilation scheme for C, Objective-C, C++ and
- Java which is enabled via -funit-at-a-time (and implied by -O2). In
- this scheme a whole file is parsed first and optimized later. The
- following basic inter-procedural optimizations are implemented:
- + Removal of unreachable functions and variables
- + Discovery of local functions (functions with static linkage
- whose address is never taken)
- + On i386, these local functions use register parameter passing
- conventions.
- + Reordering of functions in topological order of the call graph
- to enable better propagation of optimizing hints (such as the
- stack alignments needed by functions) in the back end.
- + Call graph based out-of-order inlining heuristics which allows
- to limit overall compilation unit growth (--param
- inline-unit-growth).
- Overall, the unit-at-a-time scheme produces a 1.3% improvement for
- the SPECint2000 benchmark on the i386 architecture (AMD Athlon
- CPU).
- * More realistic code size estimates used by inlining for C,
- Objective-C, C++ and Java. The growth of large functions can now be
- limited via --param large-function-insns and --param
- large-function-growth.
- * A new cfg-level loop optimizer pass replaces the old loop unrolling
- pass and adds two other loop transformations -- loop peeling and
- loop unswitching -- and also uses the profile feedback to limit
- code growth. (The three optimizations are enabled by
- -funroll-loops, -fpeel-loops and -funswitch-loops flags,
- respectively).
- The old loop unroller still can be enabled by -fold-unroll-loops
- and may produce better code in some cases, especially when the
- webizer optimization pass is not run.
- * A new web construction pass enabled via -fweb (and implied by -O3)
- improves the quality of register allocation, CSE, first scheduling
- pass and some other optimization passes by avoiding re-use of
- pseudo registers with non-overlapping live ranges. The pass almost
- always improves code quality but does make debugging difficult and
- thus is not enabled by default by -O2
- The pass is especially effective as cleanup after code duplication
- passes, such as the loop unroller or the tracer.
- * Experimental implementations of superblock or trace scheduling in
- the second scheduling pass can be enabled via
- -fsched2-use-superblocks and -fsched2-use-traces, respectively.
-
-New Languages and Language specific improvements
-
- Ada
-
- * The Ada front end has been updated to include numerous bug fixes
- and enhancements. These include:
- + Improved project file support
- + Additional set of warnings about potential wrong code
- + Improved error messages
- + Improved code generation
- + Improved cross reference information
- + Improved inlining
- + Better run-time check elimination
- + Better error recovery
- + More efficient implementation of unbounded strings
- + Added features in GNAT.Sockets, GNAT.OS_Lib, GNAT.Debug_Pools,
- ...
- + New GNAT.xxxx packages (e.g. GNAT.Strings,
- GNAT.Exception_Action)
- + New pragmas
- + New -gnatS switch replacing gnatpsta
- + Implementation of new Ada features (in particular limited
- with, limited aggregates)
-
- C/Objective-C/C++
-
- * Precompiled headers are now supported. Precompiled headers can
- dramatically speed up compilation of some projects. There are some
- known defects in the current precompiled header implementation that
- will result in compiler crashes in relatively rare situations.
- Therefore, precompiled headers should be considered a "technology
- preview" in this release. Read the manual for details about how to
- use precompiled headers.
- * File handling in the preprocessor has been rewritten. GCC no longer
- gets confused by symlinks and hardlinks, and now has a correct
- implementation of #import and #pragma once. These two directives
- have therefore been un-deprecated.
- * The undocumented extension that allowed C programs to have a label
- at the end of a compound statement, which has been deprecated since
- GCC 3.0, has been removed.
- * The cast-as-lvalue extension has been removed for C++ and
- deprecated for C and Objective-C. In particular, code like this:
- int i;
- (char) i = 5;
-
- or this:
- char *p;
- ((int *) p)++;
-
- is no longer accepted for C++ and will not be accepted for C and
- Objective-C in a future version.
- * The conditional-expression-as-lvalue extension has been deprecated
- for C and Objective-C. In particular, code like this:
- int a, b, c;
- (a ? b : c) = 2;
-
- will not be accepted for C and Objective-C in a future version.
- * The compound-expression-as-lvalue extension has been deprecated for
- C and Objective-C. In particular, code like this:
- int a, b;
- (a, b) = 2;
-
- will not be accepted for C and Objective-C in a future version. A
- possible non-intrusive workaround is the following:
- (*(a, &b)) = 2;
-
- * Several [10]built-in functions such as __builtin_popcount for
- counting bits, finding the highest and lowest bit in a word, and
- parity have been added.
- * The -fwritable-strings option has been deprecated and will be
- removed.
- * Many C math library functions are now recognized as built-ins and
- optimized.
- * The C, C++, and Objective-C compilers can now handle source files
- written in any character encoding supported by the host C library.
- The default input character set is taken from the current locale,
- and may be overridden with the -finput-charset command line option.
- In the future we will add support for inline encoding markers.
-
- C++
-
- * G++ is now much closer to full conformance to the ISO/ANSI C++
- standard. This means, among other things, that a lot of invalid
- constructs which used to be accepted in previous versions will now
- be rejected. It is very likely that existing C++ code will need to
- be fixed. This document lists some of the most common issues.
- * A hand-written recursive-descent C++ parser has replaced the
- YACC-derived C++ parser from previous GCC releases. The new parser
- contains much improved infrastructure needed for better parsing of
- C++ source codes, handling of extensions, and clean separation
- (where possible) between proper semantics analysis and parsing. The
- new parser fixes many bugs that were found in the old parser.
- * You must now use the typename and template keywords to disambiguate
- dependent names, as required by the C++ standard.
- struct K {
- typedef int mytype_t;
- };
-
- template <class T1> struct A {
- template <class T2> struct B {
- void callme(void);
- };
-
- template <int N> void bar(void)
- {
- // Use 'typename' to tell the parser that T1::mytype_t names
- // a type. This is needed because the name is dependent (in
- // this case, on template parameter T1).
- typename T1::mytype_t x;
- x = 0;
- }
- };
-
- template <class T> void template_func(void)
- {
- // Use 'template' to prefix member templates within
- // dependent types (a has type A<T>, which depends on
- // the template parameter T).
- A<T> a;
- a.template bar<0>();
-
- // Use 'template' to tell the parser that B is a nested
- // template class (dependent on template parameter T), and
- // 'typename' because the whole A<T>::B<int> is
- // the name of a type (again, dependent).
- typename A<T>::template B<int> b;
- b.callme();
- }
-
- void non_template_func(void)
- {
- // Outside of any template class or function, no names can be
- // dependent, so the use of the keyword 'typename' and 'template'
- // is not needed (and actually forbidden).
- A<K> a;
- a.bar<0>();
- A<K>::B<float> b;
- b.callme();
- }
- * In a template definition, unqualified names will no longer find
- members of a dependent base (as specified by [temp.dep]/3 in the
- C++ standard). For example,
- template <typename T> struct B {
- int m;
- int n;
- int f ();
- int g ();
- };
- int n;
- int g ();
- template <typename T> struct C : B<T> {
- void h ()
- {
- m = 0; // error
- f (); // error
- n = 0; // ::n is modified
- g (); // ::g is called
- }
- };
- You must make the names dependent, e.g. by prefixing them with
- this->. Here is the corrected definition of C<T>::h,
- template <typename T> void C<T>::h ()
- {
- this->m = 0;
- this->f ();
- this->n = 0
- this->g ();
- }
- As an alternative solution (unfortunately not backwards compatible
- with GCC 3.3), you may use using declarations instead of this->:
- template <typename T> struct C : B<T> {
- using B<T>::m;
- using B<T>::f;
- using B<T>::n;
- using B<T>::g;
- void h ()
- {
- m = 0;
- f ();
- n = 0;
- g ();
- }
- };
- * In templates, all non-dependent names are now looked up and bound
- at definition time (while parsing the code), instead of later when
- the template is instantiated. For instance:
- void foo(int);
-
- template <int> struct A {
- static void bar(void){
- foo('a');
- }
- };
-
- void foo(char);
-
- int main()
- {
- A<0>::bar(); // Calls foo(int), used to call foo(char).
- }
-
- * In an explicit instantiation of a class template, you must use
- class or struct before the template-id:
- template <int N>
- class A {};
-
- template A<0>; // error, not accepted anymore
- template class A<0>; // OK
- * The "named return value" and "implicit typename" extensions have
- been removed.
- * Default arguments in function types have been deprecated and will
- be removed.
- * ARM-style name-injection of friend declarations has been deprecated
- and will be removed. For example: struct S { friend void f(); };
- void g() { f(); } will not be accepted by future versions of G++;
- instead a declaration of "f" will need to be present outside of the
- scope of "S".
- * Covariant returns are implemented for all but varadic functions
- that require an adjustment.
- * When -pedantic is used, G++ now issues errors about spurious
- semicolons. For example,
- namespace N {}; // Invalid semicolon.
- void f() {}; // Invalid semicolon.
- * G++ no longer accepts attributes for a declarator after the
- initializer associated with that declarator. For example,
- X x(1) __attribute__((...));
- is no longer accepted. Instead, use:
- X x __attribute__((...)) (1);
- * Inside the scope of a template class, the name of the class itself
- can be treated as either a class or a template. So GCC used to
- accept the class name as argument of type template, and template
- template parameter. However this is not C++ standard compliant. Now
- the name is not treated as a valid template template argument
- unless you qualify the name by its scope. For example, the code
- below no longer compiles.
- template <template <class> class TT> class X {};
- template <class T> class Y {
- X<Y> x; // Invalid, Y is always a type template parameter.
- };
- The valid code for the above example is
- X< ::Y> x; // Valid.
- (Notice the space between < and : to prevent GCC to interpret this
- as a digraph for [.)
- * Friend declarations that refer to template specializations are
- rejected if the template has not already been declared. For
- example,
- template <typename T>
- class C {
- friend void f<> (C&);
- };
- is rejected. You must first declare f as a template,
- template <typename T>
- void f(T);
- * In case of friend declarations, every name used in the friend
- declaration must be accessible at the point of that declaration.
- Previous versions of G++ used to be less strict about this and
- allowed friend declarations for private class members, for example.
- See the ISO C++ Standard Committee's [11]defect report #209 for
- details.
- * Declaration of member functions of class templates as friends are
- supported. For example,
- template <typename T> struct A {
- void f();
- };
- class C {
- template <typename T> friend void A<T>::f();
- };
- * You must use template <> to introduce template specializations, as
- required by the standard. For example,
- template <typename T>
- struct S;
-
- struct S<int> { };
- is rejected. You must write,
- template <> struct S<int> {};
- * G++ used to accept code like this,
- struct S {
- int h();
- void f(int i = g());
- int g(int i = h());
- };
- This behavior is not mandated by the standard. Now G++ issues an
- error about this code. To avoid the error, you must move the
- declaration of g before the declaration of f. The default arguments
- for g must be visible at the point where it is called.
- * The C++ ABI Section 3.3.3 specifications for the array construction
- routines __cxa_vec_new2 and __cxa_vec_new3 were changed to return
- NULL when the allocator argument returns NULL. These changes are
- incorporated into the libstdc++ runtime library.
- * Using a name introduced by a typedef in a friend declaration or in
- an explicit instantiation is now rejected, as specified by the ISO
- C++ standard.
- class A;
- typedef A B;
- class C {
- friend class B; // error, no typedef name here
- friend B; // error, friend always needs class/struct/enum
- friend class A; // OK
- };
-
- template <int> class Q {};
- typedef Q<0> R;
- template class R; // error, no typedef name here
- template class Q<0>; // OK
- * When allocating an array with a new expression, GCC used to allow
- parentheses around the type name. This is actually ill-formed and
- it is now rejected:
- int* a = new (int)[10]; // error, not accepted anymore
- int* a = new int[10]; // OK
- * When binding an rvalue of class type to a reference, the copy
- constructor of the class must be accessible. For instance, consider
- the following code:
- class A
- {
- public:
- A();
-
- private:
- A(const A&); // private copy ctor
- };
-
- A makeA(void);
- void foo(const A&);
-
- void bar(void)
- {
- foo(A()); // error, copy ctor is not accessible
- foo(makeA()); // error, copy ctor is not accessible
-
- A a1;
- foo(a1); // OK, a1 is a lvalue
- }
- This might be surprising at first sight, especially since most
- popular compilers do not correctly implement this rule ([12]further
- details).
- * When forming a pointer to member or a pointer to member function,
- access checks for class visibility (public, protected, private) are
- now performed using the qualifying scope of the name itself. This
- is better explained with an example:
- class A
- {
- public:
- void pub_func();
- protected:
- void prot_func();
- private:
- void priv_func();
- };
-
- class B : public A
- {
- public:
- void foo()
- {
- &A::pub_func; // OK, pub_func is accessible through A
- &A::prot_func; // error, cannot access prot_func through A
- &A::priv_func; // error, cannot access priv_func through A
-
- &B::pub_func; // OK, pub_func is accessible through B
- &B::prot_func; // OK, can access prot_func through B (within B)
- &B::priv_func; // error, cannot access priv_func through B
- }
- };
-
- Runtime Library (libstdc++)
-
- * Optimization work:
- + Streamlined streambuf, filebuf, separate synched with C
- Standard I/O streambuf.
- + All formatted I/O now uses cached locale information.
- + STL optimizations (memory/speed for list, red-black trees as
- used by sets and maps).
- + More use of GCC builtins.
- + String optimizations (avoid contention on
- increment/decrement-and-test of the reference count in the
- empty-string object, constructor from input_iterators
- speedup).
- * Static linkage size reductions.
- * Large File Support (files larger than 2 GB on 32-bit systems).
- * Wide character and variable encoding filebuf work (UTF-8, Unicode).
- * Generic character traits.
- * Also support wchar_t specializations on Mac OS 10.3.x, FreeBSD 5.x,
- Solaris 2.7 and above, AIX 5.x, Irix 6.5.
- * The allocator class is now standard-conformant, and two additional
- extension allocators have been added, mt_alloc and
- bitmap_allocator.
- * PCH support: -include bits/stdc++.h (2x compile speedup).
- * Rewrote __cxa_demangle with support for C++ style allocators.
- * New debug modes for STL containers and iterators.
- * Testsuite rewrite: five times as many tests, plus increasingly
- sophisticated tests, including I/O, MT, multi-locale, wide and
- narrow characters.
- * Use current versions of GNU "autotools" for build/configuration.
-
- Objective-C
-
- * The Objective-C front end has been updated to include the numerous
- bug fixes and enhancements previously available only in Apple's
- version of GCC. These include:
- + Structured exception (@try... @catch... @finally, @throw) and
- synchronization (@synchronized) support. These are accessible
- via the -fobjc-exceptions switch; as of this writing, they may
- only be used in conjunction with -fnext-runtime on Mac OS X
- 10.3 and later. See [13]Options Controlling Objective-C
- Dialect for more information.
- + An overhaul of @encode logic. The C99 _Bool and C++ bool type
- may now be encoded as 'B'. In addition, the back-end/codegen
- dependencies have been removed.
- + An overhaul of message dispatch construction, ensuring that
- the various receiver types (and casts thereof) are handled
- properly, and that correct diagnostics are issued.
- + Support for "Zero-Link" (-fzero-link) and "Fix-and-Continue"
- (-freplace-objc-classes) debugging modes, currently available
- on Mac OS X 10.3 and later. See [14]Options Controlling
- Objective-C Dialect for more information.
- + Access to optimized runtime entry points (-fno-nil-receivers )
- on the assumption that message receivers are never nil. This
- is currently available on Mac OS X 10.3 and later. See
- [15]Options Controlling Objective-C Dialect for more
- information.
-
- Java
-
- * Compiling a .jar file will now cause non-.class entries to be
- automatically compiled as resources.
- * libgcj has been ported to Darwin.
- * Jeff Sturm has adapted Jan Hubicka's call graph optimization code
- to gcj.
- * libgcj has a new gcjlib URL type; this lets URLClassLoader load
- code from shared libraries.
- * libgcj has been much more completely merged with [16]GNU Classpath.
- * Class loading is now much more correct; in particular the caller's
- class loader is now used when that is required.
- * [17]Eclipse 2.x will run out of the box using gij.
- * Parts of java.nio have been implemented. Direct and indirect
- buffers work, as do fundamental file and socket operations.
- * java.awt has been improved, though it is still not ready for
- general use.
- * The HTTP protocol handler now uses HTTP/1.1 and can handle the POST
- method.
- * The MinGW port has matured. Enhancements include socket timeout
- support, thread interruption, improved Runtime.exec() handling and
- support for accented characters in filenames.
-
- Fortran
-
- * Fortran improvements are listed in the [18]Fortran documentation.
-
-New Targets and Target Specific Improvements
-
- Alpha
-
- * Several [19]built-in functions have been added such as
- __builtin_alpha_zap to allow utilizing the more obscure
- instructions of the CPU.
- * Parameter passing of complex arguments has changed to match the
- [20]ABI. This change is incompatible with previous GCC versions,
- but does fix compatibility with the Tru64 compiler and several
- corner cases where GCC was incompatible with itself.
-
- ARM
-
- * Nicolas Pitre has contributed his hand-coded floating-point support
- code for ARM. It is both significantly smaller and faster than the
- existing C-based implementation, even when building applications
- for Thumb. The arm-elf configuration has been converted to use the
- new code.
- * Support for the Intel's iWMMXt architecture, a second generation
- XScale processor, has been added. Enabled at run time with the
- -mcpu=iwmmxt command line switch.
- * A new ARM target has been added: arm-wince-pe. This is similar to
- the arm-pe target, but it defaults to using the APCS32 ABI.
- * The existing ARM pipeline description has been converted to the use
- the [21]DFA processor pipeline model. There is not much change in
- code performance, but the description is now [22]easier to
- understand.
- * Support for the Cirrus EP9312 Maverick floating point co-processor
- added. Enabled at run time with the -mcpu=ep9312 command line
- switch. Note however that the multilibs to support this chip are
- currently disabled in gcc/config/arm/t-arm-elf, so if you want to
- enable their production you will have to uncomment the entries in
- that file.
-
- H8/300
-
- * Support for long long has been added.
- * Support for saveall attribute has been added.
- * Pavel Pisa contributed hand-written 32-bit-by-32-bit division code
- for H8/300H and H8S, which is much faster than the previous
- implementation.
- * A lot of small performance improvements.
-
- IA-32/AMD64 (x86-64)
-
- * Tuning for K8 (AMD Opteron/Athlon64) core is available via
- -march=k8 and -mcpu=k8.
- * Scalar SSE code generation carefully avoids reformatting penalties,
- hidden dependencies and minimizes the number of uops generated on
- both Intel and AMD CPUs.
- * Vector MMX and SSE operands are now passed in registers to improve
- performance and match the argument passing convention used by the
- Intel C++ Compiler. As a result it is not possible to call
- functions accepting vector arguments compiled by older GCC version.
- * Conditional jump elimination is now more aggressive on modern CPUs.
- * The Athlon ports has been converted to use the DFA processor
- pipeline description.
- * Optimization of indirect tail calls is now possible in a similar
- fashion as direct sibcall optimization.
- * Further small performance improvements.
- * -m128bit-long-double is now less buggy.
- * __float128 support in 64-bit compilation.
- * Support for data structures exceeding 2GB in 64-bit mode.
- * -mcpu has been renamed to -mtune.
-
- IA-64
-
- * Tuning code for the Itanium 2 processor has been added. The
- generation of code tuned for Itanium 2 (option -mtune=itanium2) is
- enabled by default now. To generate code tuned for Itanium 1 the
- option -mtune=itanium1 should be used.
- * [23]DFA processor pipeline descriptions for the IA-64 processors
- have been added. This resulted in about 3% improvement on the
- SPECInt2000 benchmark for Itanium 2.
- * Instruction bundling for the IA-64 processors has been rewritten
- using the DFA pipeline hazard recognizer. It resulted in about 60%
- compiler speedup on the SPECInt2000 C programs.
-
- M32R
-
- * Support for the M32R/2 processor has been added by Renesas.
- * Support for an M32R GNU/Linux target and PIC code generation has
- been added by Renesas.
-
- M68000
-
- * Bernardo Innocenti (Develer S.r.l.) has contributed the
- m68k-uclinux target, based on former work done by Paul Dale
- (SnapGear Inc.). Code generation for the ColdFire processors family
- has been enhanced and extended to support the MCF 53xx and MCF 54xx
- cores, integrating former work done by Peter Barada (Motorola).
-
- MIPS
-
- Processor-specific changes
-
- * Support for the RM7000 and RM9000 processors has been added. It can
- be selected using the -march compiler option and should work with
- any MIPS I (mips-*) or MIPS III (mips64-*) configuration.
- * Support for revision 2 of the MIPS32 ISA has been added. It can be
- selected with the command-line option -march=mips32r2.
- * There is a new option, -mfix-sb1, to work around certain SB-1
- errata.
-
- Configuration
-
- * It is possible to customize GCC using the following configure-time
- options:
- + --with-arch, which specifies the default value of the -march
- option.
- + --with-tune, which specifies the default value of the -mtune
- option.
- + --with-abi, which specifies the default ABI.
- + --with-float=soft, which tells GCC to use software floating
- point by default.
- + --with-float=hard, which tells GCC to use hardware floating
- point by default.
- * A 64-bit GNU/Linux port has been added. The associated
- configurations are mips64-linux-gnu and mips64el-linux-gnu.
- * The 32-bit GNU/Linux port now supports Java.
- * The IRIX 6 configuration now supports the o32 ABI and will build
- o32 multilibs by default. This support is compatible with both
- binutils and the SGI tools, but note that several features,
- including debugging information and DWARF2 exception handling, are
- only available when using the GNU assembler. Use of the GNU
- assembler and linker (version 2.15 or above) is strongly
- recommended.
- * The IRIX 6 configuration now supports 128-bit long doubles.
- * There are two new RTEMS-specific configurations, mips-rtems and
- mipsel-rtems.
- * There are two new *-elf configurations, mipsisa32r2-elf and
- mipsisa32r2el-elf.
-
- General
-
- * Several [24]ABI bugs have been fixed. Unfortunately, these changes
- will break binary compatibility with earlier releases.
- * GCC can now use explicit relocation operators when generating
- -mabicalls code. This behavior is controlled by -mexplicit-relocs
- and can have several performance benefits. For example:
- + It allows for more optimization of GOT accesses, including
- better scheduling and redundancy elimination.
- + It allows sibling calls to be implemented as jumps.
- + n32 and n64 leaf functions can use a call-clobbered global
- pointer instead of $28.
- + The code to set up $gp can be removed from functions that
- don't need it.
- * A new option, -mxgot, allows the GOT to be bigger than 64k. This
- option is equivalent to the assembler's -xgot option and should be
- used instead of -Wa,-xgot.
- * Frame pointer elimination is now supported when generating 64-bit
- MIPS16 code.
- * Inline block moves have been optimized to take more account of
- alignment information.
- * Many internal changes have been made to the MIPS port, mostly aimed
- at reducing the reliance on assembler macros.
-
- PowerPC
-
- * GCC 3.4 releases have a number of fixes for PowerPC and PowerPC64
- [25]ABI incompatibilities regarding the way parameters are passed
- during functions calls. These changes may result in incompatibility
- between code compiled with GCC 3.3 and GCC 3.4.
-
- PowerPC Darwin
-
- * Support for shared/dylib gcc libraries has been added. It is
- enabled by default on powerpc-apple-darwin7.0.0 and up.
- * Libgcj is enabled by default. On systems older than
- powerpc-apple-darwin7.0.0 you need to install dlcompat.
- * 128-bit IBM extended precision format support added for long
- double.
-
- PowerPC64 GNU/Linux
-
- * By default, PowerPC64 GNU/Linux now uses natural alignment of
- structure elements. The old four byte alignment for double, with
- special rules for a struct starting with a double, can be chosen
- with -malign-power. This change may result in incompatibility
- between code compiled with GCC 3.3 and GCC 3.4.
- * -mabi=altivec is now the default rather than -mabi=no-altivec.
- * 128-bit IBM extended precision format support added for long
- double.
-
- S/390 and zSeries
-
- * New command-line options allow to specify the intended execution
- environment for generated code:
- + -mesa/-mzarch allows to specify whether to generate code
- running in ESA/390 mode or in z/Architecture mode (this is
- applicable to 31-bit code only).
- + -march allows to specify a minimum processor architecture
- level (g5, g6, z900, or z990).
- + -mtune allows to specify which processor to tune for.
- * It is possible to customize GCC using the following configure-time
- options:
- + --with-mode, which specifies whether to default to assuming
- ESA/390 or z/Architecture mode.
- + --with-arch, which specifies the default value of the -march
- option.
- + --with-tune, which specifies the default value of the -mtune
- option.
- * Support for the z990 processor has been added, and can be selected
- using -march=z990 or -mtune=z990. This includes instruction
- scheduling tuned for the superscalar instruction pipeline of the
- z990 processor as well as support for all new instructions provided
- by the long-displacement facility.
- * Support to generate 31-bit code optimized for zSeries processors
- (running in ESA/390 or in z/Architecture mode) has been added. This
- can be selected using -march=z900 and -mzarch respectively.
- * Instruction scheduling for the z900 and z990 processors now uses
- the DFA pipeline hazard recognizer.
- * GCC no longer generates code to maintain a stack backchain,
- previously used to generate stack backtraces for debugging
- purposes. As replacement that does not incur runtime overhead,
- DWARF-2 call frame information is provided by GCC; this is
- supported by GDB 6.1. The old behavior can be restored using the
- -mbackchain option.
- * The stack frame size of functions may now exceed 2 GB in 64-bit
- code.
- * A port for the 64-bit IBM TPF operating system has been added; the
- configuration is s390x-ibm-tpf. This configuration is supported as
- cross-compilation target only.
- * Various changes to improve the generated code have been
- implemented, including:
- + GCC now uses the MULTIPLY AND ADD and MULTIPLY AND SUBTRACT
- instructions to significantly speed up many floating-point
- applications.
- + GCC now uses the ADD LOGICAL WITH CARRY and SUBTRACT LOGICAL
- WITH BORROW instructions to speed up long long arithmetic.
- + GCC now uses the SEARCH STRING instruction to implement
- strlen().
- + In many cases, function call overhead for 31-bit code has been
- reduced by placing the literal pool after the function code
- instead of after the function prolog.
- + Register 14 is no longer reserved in 64-bit code.
- + Handling of global register variables has been improved.
-
- SPARC
-
- * The option -mflat is deprecated.
- * Support for large (> 2GB) frames has been added to the 64-bit port.
- * Several [26]ABI bugs have been fixed. Unfortunately, these changes
- will break binary compatibility with earlier releases.
- * The default debugging format has been switched from STABS to
- DWARF-2 for 32-bit code on Solaris 7 and later. DWARF-2 is already
- the default debugging format for 64-bit code on Solaris.
-
- SuperH
-
- * Support for the SH2E processor has been added. Enabled at run time
- with the -m2e command line switch, or at configure time by
- specifying sh2e as the machine part of the target triple.
-
- V850
-
- * Support for the Mitsubishi V850E1 processor has been added. This is
- a variant of the V850E processor with some additional debugging
- instructions.
-
- Xtensa
-
- * Several ABI bugs have been fixed. Unfortunately, these changes
- break binary compatibility with earlier releases.
- + For big-endian processors, the padding of aggregate return
- values larger than a word has changed. If the size of an
- aggregate return value is not a multiple of 32 bits, previous
- versions of GCC inserted padding in the most-significant bytes
- of the first return value register. Aggregates larger than a
- word are now padded in the least-significant bytes of the last
- return value register used. Aggregates smaller than a word are
- still padded in the most-significant bytes. The return value
- padding has not changed for little-endian processors.
- + Function arguments with 16-byte alignment are now properly
- aligned.
- + The implementation of the va_list type has changed. A va_list
- value created by va_start from a previous release cannot be
- used with va_arg from this release, or vice versa.
- * More processor configuration options for Xtensa processors are
- supported:
- + the ABS instruction is now optional;
- + the ADDX* and SUBX* instructions are now optional;
- + an experimental CONST16 instruction can be used to synthesize
- constants instead of loading them from constant pools.
- These and other Xtensa processor configuration options can no
- longer be enabled or disabled by command-line options; the
- processor configuration must be specified by the xtensa-config.h
- header file when building GCC. Additionally, the
- -mno-serialize-volatile option is no longer supported.
-
-Obsolete Systems
-
- Support for a number of older systems has been declared obsolete in GCC
- 3.4. Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
-
- All configurations of the following processor architectures have been
- declared obsolete:
- * Mitsubishi D30V, d30v-*
- * AT&T DSP1600 and DSP1610, dsp16xx-*
- * Intel 80960, i960
-
- Also, some individual systems have been obsoleted:
- * ARM Family
- + Support for generating code for operation in APCS/26 mode
- (-mapcs-26).
- * IBM ESA/390
- + "Bigfoot" port, i370-*. (The other port, s390-*, is actively
- maintained and supported.)
- * Intel 386 family
- + MOSS, i?86-moss-msdos and i?86-*-moss*
- + NCR 3000 running System V r.4, i?86-ncr-sysv4*
- + FreeBSD with a.out object format, i?86-*-freebsd*aout* and
- i?86-*-freebsd2*
- + GNU/Linux with a.out object format, i?86-linux*aout*
- + GNU/Linux with libc5, a.k.a. glibc1, i?86-linux*libc1*
- + Interix versions before Interix 3, i?86-*-interix
- + Mach microkernel, i?86-mach*
- + SCO UnixWare with UDK, i?86-*-udk*
- + Generic System V releases 1, 2, and 3, i?86-*-sysv[123]*
- + VSTa microkernel, i386-*-vsta
- * Motorola M68000 family
- + HPUX, m68k-hp-hpux* and m68000-hp-hpux*
- + NetBSD with a.out object format (before NetBSD 1.4),
- m68k-*-*-netbsd* except m68k-*-*-netbsdelf*
- + Generic System V r.4, m68k-*-sysv4*
- * VAX
- + Generic VAX, vax-*-* (This is generic VAX only; we have not
- obsoleted any VAX triples for specific operating systems.)
-
-Documentation improvements
-
-Other significant improvements
-
- * The build system has undergone several significant cleanups.
- Subdirectories will only be configured if they are being built, and
- all subdirectory configures are run from the make command. The top
- level has been autoconfiscated.
- * Building GCC no longer writes to its source directory. This should
- help those wishing to share a read-only source directory over NFS
- or build from a CD. The exceptions to this feature are if you
- configure with either --enable-maintainer-mode or
- --enable-generated-files-in-srcdir.
- * The -W warning option has been renamed to -Wextra, which is more
- easily understood. The older spelling will be retained for
- backwards compatibility.
- * Substantial improvements in compile time have been made,
- particularly for non-optimizing compilations.
- __________________________________________________________________
-
-GCC 3.4.0
-
- Bug Fixes
-
- A vast number of bugs have been fixed in 3.4.0, too many to publish a
- complete list here. [27]Follow this link to query the Bugzilla database
- for the list of over 900 bugs fixed in 3.4.0. This is the list of all
- bugs marked as resolved and fixed in 3.4.0 that are not flagged as 3.4
- regressions.
- __________________________________________________________________
-
-GCC 3.4.1
-
- Bug Fixes
-
- This section lists the problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.4.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Bootstrap failures
-
- * [28]10129 Ada bootstrap fails on PPC-Darwin - invalid assembler
- emitted - PIC related
- * [29]14576 [ARM] ICE in libiberty when building gcc-3.4 for arm-elf
- * [30]14760 A bug in configure.in prevents using both
- --program-suffix and --program-prefix
- * [31]14671 [hppa64] bootstrap fails: ICE in
- save_call_clobbered_regs, in caller_save.c
- * [32]15093 [alpha][Java] make bootstrap fails to configure libffi on
- Alpha
- * [33]15178 Solaris 9/x86 fails linking after stage 3
-
- Multi-platform internal compiler errors (ICEs)
-
- * [34]12753 (preprocessor) Memory corruption in preprocessor on bad
- input
- * [35]13985 ICE in gcc.c-torture/compile/930621-1.c
- * [36]14810 (c++) tree check failures with invalid code involving
- templates
- * [37]14883 (c++) ICE on invalid code, in cp_parser_lookup_name, in
- cp/parser.c
- * [38]15044 (c++) ICE on syntax error, template header
- * [39]15057 (c++) Compiling of conditional value throw constructs
- cause a segmentation violation
- * [40]15064 (c++) typeid of template parameter gives ICE
- * [41]15142 (c++) ICE when passing a string where a char* is expected
- in a throw statement
- * [42]15159 ICE in rtl_verify_flow_info_1
- * [43]15165 (c++) ICE in instantiate_template
- * [44]15193 Unary minus using pointer to V4SF vector causes
- -fforce-mem to exhaust all memory
- * [45]15209 (c++) Runs out of memory with packed structs
- * [46]15227 (c++) Trouble with invalid function definition
- * [47]15285 (c++) instantiate_type ICE when forming pointer to
- template function
- * [48]15299 (c++) ICE in resolve_overloaded_unification
- * [49]15329 (c++) ICE on constructor of member template
- * [50]15550 ICE in extract_insn, in recog.c
- * [51]15554 (c++) ICE in tsubst_copy, in cp/pt.c
- * [52]15640 (c++) ICE on invalid code in arg_assoc, in
- cp/name-lookup.c
- * [53]15666 [unit-at-a-time] Gcc abort on valid code
- * [54]15696 (c++) ICE with bad pointer-to-member code
- * [55]15701 (c++) ICE with friends and template template parameter
- * [56]15761 ICE in do_SUBST, in combine.c
- * [57]15829 (c++) ICE on Botan-1.3.13 due to -funroll-loops
-
- Ada
-
- * [58]14538 All RTEMS targets broken for gnat
-
- C front end
-
- * [59]12391 missing warning about assigning to an incomplete type
- * [60]14649 atan(1.0) should not be a constant expression
- * [61]15004 [unit-at-a-time] no warning for unused paramater in
- static function
- * [62]15749 --pedantic-errors behaves differently from --pedantic
- with C-compiler on GNU/Linux
-
- C++ compiler and library
-
- * [63]10646 non-const reference is incorrectly matched in a "const T"
- partial specialization
- * [64]12077 wcin.rdbuf()->in_avail() return value too high
- * [65]13598 enc_filebuf doesn't work
- * [66]14211 const_cast returns lvalue but should be rvalue
- * [67]14220 num_put::do_put() undesired float/double behavior
- * [68]14245 problem with user-defined allocators in std::basic_string
- * [69]14340 libstdc++ Debug mode: failure to convert iterator to
- const_iterator
- * [70]14600 __gnu_cxx::stdio_sync_filebuf should expose internal
- FILE*
- * [71]14668 no warning anymore for reevaluation of declaration
- * [72]14775 LFS (large file support) tests missing
- * [73]14821 Duplicate namespace alias declaration should not conflict
- * [74]14930 Friend declaration ignored
- * [75]14932 cannot use offsetof to get offsets of array elements in
- g++ 3.4.0
- * [76]14950 [non unit-at-a-time] always_inline does not mix with
- templates and -O0
- * [77]14962 g++ ignores #pragma redefine_extname
- * [78]14975 Segfault on low-level write error during imbue
- * [79]15002 Linewise stream input is unusably slow (std::string slow)
- * [80]15025 compiler accepts redeclaration of template as
- non-template
- * [81]15046 [arm] Math functions misdetected by cross configuration
- * [82]15069 a bit test on a variable of enum type is miscompiled
- * [83]15074 g++ -lsupc++ still links against libstdc++
- * [84]15083 spurious "statement has no effect" warning
- * [85]15096 parse error with templates and pointer to const member
- * [86]15287 combination of operator[] and operator .* fails in
- templates
- * [87]15317 __attribute__ unused in first parameter of constructor
- gives error
- * [88]15337 sizeof on incomplete type diagnostic
- * [89]15361 bitset<>::_Find_next fails
- * [90]15412 _GLIBCXX_ symbols symbols defined and used in different
- namespaces
- * [91]15427 valid code results in incomplete type error
- * [92]15471 Incorrect member pointer offsets in anonymous
- structs/unions
- * [93]15503 nested template problem
- * [94]15507 compiler hangs while laying out union
- * [95]15542 operator & and template definitions
- * [96]15565 SLES9: leading + sign for unsigned int with showpos
- * [97]15625 friend defined inside a template fails to find static
- function
- * [98]15629 Function templates, overloads, and friend name injection
- * [99]15742 'noreturn' attribute ignored in method of template
- functions.
- * [100]15775 Allocator::pointer consistently ignored
- * [101]15821 Duplicate namespace alias within namespace rejected
- * [102]15862 'enum yn' fails (confict with undeclared builtin)
- * [103]15875 rejects pointer to member in template
- * [104]15877 valid code using templates and anonymous enums is
- rejected
- * [105]15947 Puzzling error message for wrong destructor declaration
- in template class
- * [106]16020 cannot copy __gnu_debug::bitset
- * [107]16154 input iterator concept too restrictive
- * [108]16174 deducing top-level consts
-
- Java
-
- * [109]14315 Java compiler is not parallel make safe
-
- Fortran
-
- * [110]15151 [g77] incorrect logical i/o in 64-bit mode
-
- Objective-C
-
- * [111]7993 private variables cannot be shadowed in subclasses
-
- Optimization bugs
-
- * [112]15228 useless copies of floating point operands
- * [113]15345 [non-unit-at-a-time] unreferenced nested inline
- functions not optimized away
- * [114]15945 Incorrect floating point optimization
- * [115]15526 ftrapv aborts on 0 * (-1)
- * [116]14690 Miscompiled POOMA tests
- * [117]15112 GCC generates code to write to unchanging memory
-
- Preprocessor
-
- * [118]15067 Minor glitch in the source of cpp
-
- Main driver program bugs
-
- * [119]1963 collect2 interprets -oldstyle_liblookup as -o
- ldstyle_liblookup
-
- x86-specific (Intel/AMD)
-
- * [120]15717 Error: can't resolve `L0' {*ABS* section} - `xx' {*UND*
- section}
-
- HPPA-specific
-
- * [121]14782 GCC produces an unaligned data access at -O2
- * [122]14828 FAIL: gcc.c-torture/execute/20030408-1.c execution, -O2
- * [123]15202 ICE in reload_cse_simplify_operands, in postreload.c
-
- IA64-specific
-
- * [124]14610 __float80 constants incorrectly emitted
- * [125]14813 init_array sections are initialized in the wrong order
- * [126]14857 GCC segfault on duplicated asm statement
- * [127]15598 Gcc 3.4 ICE on valid code
- * [128]15653 Gcc 3.4 ICE on valid code
-
- MIPS-specific
-
- * [129]15189 wrong filling of delay slot with -march=mips1 -G0
- -mno-split-addresses -mno-explicit-relocs
- * [130]15331 Assembler error building gnatlib on IRIX 6.5 with GNU as
- 2.14.91
- * [131]16144 Bogus reference to __divdf3 when -O1
- * [132]16176 Miscompilation of unaligned data in MIPS backend
-
- PowerPC-specific
-
- * [133]11591 ICE in gcc.dg/altivec-5.c
- * [134]12028 powerpc-eabispe produces bad sCOND operation
- * [135]14478 rs6000 geu/ltu patterns generate incorrect code
- * [136]14567 long double and va_arg complex args
- * [137]14715 Altivec stack layout may overlap gpr save with stack
- temps
- * [138]14902 (libstdc++) Stream checking functions fail when -pthread
- option is used.
- * [139]14924 Compiler ICE on valid code
- * [140]14960 -maltivec affects vector return with -mabi=no-altivec
- * [141]15106 vector varargs failure passing from altivec to
- non-altivec code for -m32
- * [142]16026 ICE in function.c:4804, assign_parms, when -mpowerpc64 &
- half-word operation
- * [143]15191 -maltivec -mabi=no-altivec results in mis-aligned lvx
- and stvx
- * [144]15662 Segmentation fault when an exception is thrown - even if
- try and catch are specified
-
- s390-specific
-
- * [145]15054 Bad code due to overlapping stack temporaries
-
- SPARC-specific
-
- * [146]15783 ICE with union assignment in 64-bit mode
- * [147]15626 GCC 3.4 emits "ld: warning: relocation error:
- R_SPARC_UA32"
-
- x86-64-specific
-
- * [148]14326 boehm-gc hardcodes to 3DNow! prefetch for x86_64
- * [149]14723 Backported -march=nocona from mainline
- * [150]15290 __float128 failed to pass to function properly
-
- Cygwin/Mingw32-specific
-
- * [151]15250 Option -mms-bitfields support on GCC 3.4 is not
- conformant to MS layout
- * [152]15551 -mtune=pentium4 -O2 with sjlj EH breaks stack probe
- worker on windows32 targets
-
- Bugs specific to embedded processors
-
- * [153]8309 [m68k] -m5200 produces erroneous SImode set of short
- varaible on stack
- * [154]13250 [SH] Gcc code for rotation clobbers the register, but
- gcc continues to use the register as if it was not clobbered
- * [155]13803 [coldfire] movqi operand constraints too restrictivefor
- TARGET_COLDFIRE
- * [156]14093 [SH] ICE for code when using -mhitachi option in SH
- * [157]14457 [m6811hc] ICE with simple c++ source
- * [158]14542 [m6811hc] ICE on simple source
- * [159]15100 [SH] cc1plus got hang-up on
- libstdc++-v3/testsuite/abi_check.cc
- * [160]15296 [CRIS] Delayed branch scheduling causing invalid code on
- cris-*
- * [161]15396 [SH] ICE with -O2 -fPIC
- * [162]15782 [coldfire] m68k_output_mi_thunk emits wrong code for
- ColdFire
-
- Testsuite problems (compiler not affected)
-
- * [163]11610 libstdc++ testcases 27_io/* don't work properly remotely
- * [164]15488 (libstdc++) possibly insufficient file permissions for
- executing test suite
- * [165]15489 (libstdc++) testsuite_files determined incorrectly
-
- Documentation bugs
-
- * [166]13928 (libstdc++) no whatis info in some man pages generated
- by doxygen
- * [167]14150 Ada documentation out of date
- * [168]14949 (c++) Need to document method visibility changes
- * [169]15123 libstdc++-doc: Allocators.3 manpage is empty
- __________________________________________________________________
-
-GCC 3.4.2
-
- Bug Fixes
-
- This section lists the problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.4.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Bootstrap failures and issues
-
- * [170]16469 [mips-sgi-irix5.3] bootstrap fails in
- libstdc++-v3/testsuite
- * [171]16344 [hppa-linux-gnu] libstdc++'s PCH built by
- profiledbootstrap does not work with the built compiler
- * [172]16842 [Solaris/x86] mkheaders can not find mkheaders.conf
-
- Multi-platform internal compiler errors (ICEs)
-
- * [173]12608 (c++) ICE: expected class 't', have 'x' (error_mark) in
- cp_parser_class_specifier, in cp/parser.c
- * [174]14492 ICE in loc_descriptor_from_tree, in dwarf2out.c
- * [175]15461 (c++) ICE due to NRV and inlining
- * [176]15890 (c++) ICE in c_expand_expr, in c-common.c
- * [177]16180 ICE: segmentation fault in RTL optimization
- * [178]16224 (c++) ICE in write_unscoped_name (template/namespace)
- * [179]16408 ICE: in delete_insn, in cfgrtl.c
- * [180]16529 (c++) ICE for: namespace-alias shall not be declared as
- the name of any other entity
- * [181]16698 (c++) ICE with exceptions and declaration of __cxa_throw
- * [182]16706 (c++) ICE in finish_member_declaration, in
- cp/semantics.c
- * [183]16810 (c++) Legal C++ program with cast gives ICE in
- build_ptrmemfunc
- * [184]16851 (c++) ICE when throwing a comma expression
- * [185]16870 (c++) Boost.Spirit causes ICE in tsubst, in cp/pt.c
- * [186]16904 (c++) ICE in finish_class_member_access_expr, in
- cp/typeck.c
- * [187]16905 (c++) ICE (segfault) with exceptions
- * [188]16964 (c++) ICE in cp_parser_class_specifier due to
- redefinition
- * [189]17068 (c++) ICE: tree check: expected class 'd', have 'x'
- (identifier_node) in dependent_template_p, in cp/pt.c
-
- Preprocessor bugs
-
- * [190]16366 Preprocessor option -remap causes memory corruption
-
- Optimization
-
- * [191]15345 unreferenced nested inline functions not optimized away
- * [192]16590 Incorrect execution when compiling with -O2
- * [193]16693 Bitwise AND is lost when used within a cast to an enum
- of the same precision
- * [194]17078 Jump into if(0) substatement fails
-
- Problems in generated debug information
-
- * [195]13956 incorrect stabs for nested local variables
-
- C front end bugs
-
- * [196]16684 GCC should not warn about redundant redeclarations of
- built-ins
-
- C++ compiler and library
-
- * [197]12658 Thread safety problems in locale::global() and
- locale::locale()
- * [198]13092 g++ accepts invalid pointer-to-member conversion
- * [199]15320 Excessive memory consumption
- * [200]16246 Incorrect template argument deduction
- * [201]16273 Memory exhausted when using nested classes and virtual
- functions
- * [202]16401 ostringstream in gcc 3.4.x very slow for big data
- * [203]16411 undefined reference to
- __gnu_cxx::stdio_sync_filebuf<char, std::char_traits<char>
- >::file()
- * [204]16489 G++ incorrectly rejects use of a null constant integral
- expression as a null constant pointer
- * [205]16618 offsetof fails with constant member
- * [206]16637 syntax error reported for valid input code
- * [207]16717 __attribute__((constructor)) broken in C++
- * [208]16813 compiler error in DEBUG version of range insertion
- std::map::insert
- * [209]16853 pointer-to-member initialization from incompatible one
- accepted
- * [210]16889 ambiguity is not detected
- * [211]16959 Segmentation fault in ios_base::sync_with_stdio
-
- Java compiler and library
-
- * [212]7587 direct threaded interpreter not thread-safe
- * [213]16473 ServerSocket accept() leaks file descriptors
- * [214]16478 Hash synchronization deadlock with finalizers
-
- Alpha-specific
-
- * [215]10695 ICE in dwarf2out_frame_debug_expr, in dwarf2out.c
- * [216]16974 could not split insn (ice in final_scan_insn, in
- final.c)
-
- x86-specific
-
- * [217]16298 ICE in output_operand
- * [218]17113 ICE with SSE2 intrinsics
-
- x86-64 specific
-
- * [219]14697 libstdc++ couldn't find 32bit libgcc_s
-
- MIPS-specific
-
- * [220]15869 [mips64] No NOP after LW (with -mips1 -O0)
- * [221]16325 [mips64] value profiling clobbers gp on mips
- * [222]16357 [mipsisa64-elf] ICE copying 7 bytes between extern
- char[]s
- * [223]16380 [mips64] Use of uninitialised register after dbra
- conversion
- * [224]16407 [mips64] Unaligned access to local variables
- * [225]16643 [mips64] verify_local_live_at_start ICE after
- crossjumping & cfgcleanup
-
- ARM-specific
-
- * [226]15927 THUMB -O2: strength-reduced iteration variable ends up
- off by 1
- * [227]15948 THUMB: ICE with non-commutative cbranch
- * [228]17019 THUMB: bad switch statement in md code for
- addsi3_cbranch_scratch
-
- IA64-specific
-
- * [229]16130 ICE on valid code: in bundling, in config/ia64/ia64.c
- (-mtune=merced)
- * [230]16142 ICE on valid code: in bundling, in config/ia64/ia64.c
- (-mtune=itanium)
- * [231]16278 Gcc failed to build Linux kernel with -mtune=merced
- * [232]16414 ICE on valid code: typo in comparison of asm_noperands
- result
- * [233]16445 ICE on valid code: don't count ignored insns
- * [234]16490 ICE (segfault) while compiling with -fprofile-use
- * [235]16683 ia64 does not honor SUBTARGET_EXTRA_SPECS
-
- PowerPC-specific
-
- * [236]16195 (ppc64): Miscompilation of GCC 3.3.x by 3.4.x
- * [237]16239 ICE on ppc64 (mozilla 1.7 compile, -O1 -fno-exceptions
- issue)
-
- SPARC-specific
-
- * [238]16199 ICE while compiling apache 2.0.49
- * [239]16416 -m64 doesn't imply -mcpu=v9 anymore
- * [240]16430 ICE when returning non-C aggregates larger than 16 bytes
-
- Bugs specific to embedded processors
-
- * [241]16379 [m32r] can't output large model function call of memcpy
- * [242]17093 [m32r] ICE with -msdata=use -O0
- * [243]17119 [m32r] ICE at switch case 0x8000
-
- DJGPP-specific
-
- * [244]15928 libstdc++ in 3.4.x doesn't cross-compile for djgpp
-
- Alpha Tru64-specific
-
- * [245]16210 libstdc++ gratuitously omits "long long" I/O
-
- Testsuite, documentation issues (compiler is not affected):
-
- * [246]15488 (libstdc++) possibly insufficient file permissions for
- executing test suite
- * [247]16250 ada/doctools runs makeinfo even in release tarball
- __________________________________________________________________
-
-GCC 3.4.3
-
- This is the [248]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.4.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Bootstrap failures
-
- * [249]17369 [ia64] Bootstrap failure with binutils-2.15.90.0.1.1
- * [250]17850 [arm-elf] bootstrap failure - libstdc++ uses strtold
- when undeclared
-
- Internal compiler errors (ICEs) affecting multiple platforms
-
- * [251]13948 (java) GCJ segmentation fault while compiling GL4Java
- .class files
- * [252]14492 ICE in loc_descriptor_from_tree, in dwarf2out.c
- * [253]16301 (c++) ICE when "strong" attribute is attached to a using
- directive
- * [254]16566 ICE with flexible arrays
- * [255]17023 ICE with nested functions in parameter declaration
- * [256]17027 ICE with noreturn function in loop at -O2
- * [257]17524 ICE in grokdeclarator, in cp/decl.c
- * [258]17826 (c++) ICE in cp_tree_equal
-
- C and optimization bugs
-
- * [259]15526 -ftrapv aborts on 0 * (-1)
- * [260]16999 #ident stopped working
- * [261]17503 quadratic behaviour in invalid_mode_change_p
- * [262]17581 Long long arithmetic fails inside a switch/case
- statement when compiled with -O2
- * [263]18129 -fwritable-strings doesn't work
-
- C++ compiler and library bugs
-
- * [264]10975 incorrect initial ostringstream::tellp()
- * [265]11722 Unbuffered filebuf::sgetn is slow
- * [266]14534 Unrecognizing static function as a template parameter
- when its return value is also templated
- * [267]15172 Copy constructor optimization in aggregate
- initialization
- * [268]15786 Bad error message for frequently occuring error.
- * [269]16162 Rejects valid member-template-definition
- * [270]16612 empty basic_strings can't live in shared memory
- * [271]16715 std::basic_iostream is instantiated when used, even
- though instantiations are already contained in libstdc++
- * [272]16848 code in /ext/demangle.h appears broken
- * [273]17132 GCC fails to eliminate function template specialization
- when argument deduction fails
- * [274]17259 One more _S_leaf incorrectly qualified with _RopeRep::
- in ropeimpl.h
- * [275]17327 use of `enumeral_type' in template type unification
- * [276]17393 "unused variable '._0'" warning with -Wall
- * [277]17501 Confusion with member templates
- * [278]17537 g++ not passing -lstdc++ to linker when all command line
- arguments are libraries
- * [279]17585 usage of unqualified name of static member from within
- class not allowed
- * [280]17821 Poor diagnostic for using "." instead of "->"
- * [281]17829 wrong error: call of overloaded function is ambiguous
- * [282]17851 Misleading diagnostic for invalid function declarations
- with undeclared types
- * [283]17976 Destructor is called twice
- * [284]18020 rejects valid definition of enum value in template
- * [285]18093 bogus conflict in namespace aliasing
- * [286]18140 C++ parser bug when using >> in templates
-
- Fortran
-
- * [287]17541 data statements with double precision constants fail
-
- x86-specific
-
- * [288]17853 -O2 ICE for MMX testcase
-
- SPARC-specific
-
- * [289]17245 ICE compiling gsl-1.5 statistics/lag1.c
-
- Darwin-specific
-
- * [290]17167 FATAL:Symbol L_foo$stub already defined.
-
- AIX-specific
-
- * [291]17277 could not catch an exception when specified -maix64
-
- Solaris-specific
-
- * [292]17505 <cmath> calls acosf(), ceilf(), and other functions
- missing from system libraries
-
- HP/UX specific:
-
- * [293]17684 /usr/ccs/bin/ld: Can't create libgcc_s.sl
-
- ARM-specific
-
- * [294]17384 ICE with mode attribute on structures
-
- MIPS-specific
-
- * [295]17770 No NOP after LWL with -mips1
-
- Other embedded target specific
-
- * [296]11476 [arc-elf] gcc ICE on newlib's vfprintf.c
- * [297]14064 [avr-elf] -fdata-sections triggers ICE
- * [298]14678 [m68hc11-elf] gcc ICE
- * [299]15583 [powerpc-rtems] powerpc-rtems lacks __USE_INIT_FINI__
- * [300]15790 [i686-coff] Alignment error building gcc with i686-coff
- target
- * [301]15886 [SH] Miscompilation with -O2 -fPIC
- * [302]16884 [avr-elf] [fweb related] bug while initializing
- variables
-
- Bugs relating to debugger support
-
- * [303]13841 missing debug info for _Complex function arguments
- * [304]15860 [big-endian targets] No DW_AT_location debug info is
- emitted for formal arguments to a function that uses "register"
- qualifiers
-
- Testsuite issues (compiler not affected)
-
- * [305]17465 Testsuite in libffi overrides LD_LIBRARY_PATH
- * [306]17469 Testsuite in libstdc++ overrides LD_LIBRARY_PATH
- * [307]18138 [mips-sgi-irix6.5] libgcc_s.so.1 not found by 64-bit
- testsuite
-
- Documentation
-
- * [308]15498 typo in gcc manual: non-existing locale example en_UK,
- should be en_GB
- * [309]15747 [mips-sgi-irix5.3] /bin/sh hangs during bootstrap:
- document broken shell
- * [310]16406 USE_LD_AS_NEEDED undocumented
- __________________________________________________________________
-
-GCC 3.4.4
-
- This is the [311]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.4.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
- __________________________________________________________________
-
-GCC 3.4.5
-
- This is the [312]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.4.5 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Bootstrap issues
-
- * [313]24688 sco_math fixincl breaks math.h
-
- C compiler bugs
-
- * [314]17188 struct Foo { } redefinition
- * [315]20187 wrong code for ((unsigned char)(unsigned long
- long)((a?a:1)&(a*b)))?0:1)
- * [316]21873 infinite warning loop on bad array initializer
- * [317]21899 enum definition accepts values to be overriden
- * [318]22061 ICE in find_function_data, in function.c
- * [319]22308 Failure to diagnose violation of constraint 6.516p2
- * [320]22458 ICE on missing brace
- * [321]22589 ICE casting to long long
- * [322]24101 Segfault with preprocessed source
-
- C++ compiler and library bugs
-
- * [323]10611 operations on vector mode not recognized in C++
- * [324]13377 unexpected behavior of namespace usage directive
- * [325]16002 Strange error message with new parser
- * [326]17413 local classes as template argument
- * [327]17609 spurious error message after using keyword
- * [328]17618 ICE in cp_convert_to_pointer, in cp/cvt.c
- * [329]18124 ICE with invalid template template parameter
- * [330]18155 typedef in template declaration not rejected
- * [331]18177 ICE with const_cast for undeclared variable
- * [332]18368 C++ error message regression
- * [333]16378 ICE when returning a copy of a packed member
- * [334]18466 int ::i; accepted
- * [335]18512 ICE on invalid usage of template base class
- * [336]18454 ICE when returning undefined type
- * [337]18738 typename not allowed with non-dependent qualified name
- * [338]18803 rejects access to operator() in template
- * [339]19004 ICE in uses_template_parms, in cp/pt.c
- * [340]19208 Spurious error about variably modified type
- * [341]18253 bad error message / ICE for invalid template parameter
- * [342]19608 ICE after friend function definition in local class
- * [343]19884 ICE on explicit instantiation of a non-template
- constructor
- * [344]20153 ICE when C++ template function contains anonymous union
- * [345]20563 Infinite loop in diagnostic (and ice after error
- message)
- * [346]20789 ICE with incomplete type in template
- * [347]21336 Internal compiler error when using custom new operators
- * [348]21768 ICE in error message due to violation of coding
- conventions
- * [349]21853 constness of pointer to data member ignored
- * [350]21903 Default argument of template function causes a
- compile-time error
- * [351]21983 multiple diagnostics
- * [352]21987 New testsuite failure
- g++.dg/warn/conversion-function-1.C
- * [353]22153 ICE on invalid template specialization
- * [354]22172 Internal compiler error, seg fault.
- * [355]21286 filebuf::xsgetn vs pipes
- * [356]22233 ICE with wrong number of template parameters
- * [357]22508 ICE after invalid operator new
- * [358]22545 ICE with pointer to class member & user defined
- conversion operator
- * [359]23528 Wrong default allocator in ext/hash_map
- * [360]23550 char_traits requirements/1.cc test bad math
- * [361]23586 Bad diagnostic for invalid namespace-name
- * [362]23624 ICE in invert_truthvalue, in fold-const.c
- * [363]23639 Bad error message: not a member of '<declaration error>'
- * [364]23797 ICE on typename outside template
- * [365]23965 Bogus error message: no matching function for call to
- 'foo(<type error>)'
- * [366]24052 &#`label_decl' not supported by dump_expr#<expression
- error>
- * [367]24580 virtual base class cause exception not to be caught
-
- Problems in generated debug information
-
- * [368]24267 Bad DWARF for altivec vectors
-
- Optimizations issues
-
- * [369]17810 ICE in verify_local_live_at_start
- * [370]17860 Wrong generated code for loop with varying bound
- * [371]21709 ICE on compile-time complex NaN
- * [372]21964 broken tail call at -O2 or more
- * [373]22167 Strange optimization bug when using -Os
- * [374]22619 Compilation failure for real_const_1.f and
- real_const_2.f90
- * [375]23241 Invalid code generated for comparison of uchar to 255
- * [376]23478 Miscompilation due to reloading of a var that is also
- used in EH pad
- * [377]24470 segmentation fault in cc1plus when compiling with -O
- * [378]24950 ICE in operand_subword_force
-
- Precompiled headers problems
-
- * [379]14400 Cannot compile qt-x11-free-3.3.0
- * [380]14940 PCH largefile test fails on various platforms
-
- Preprocessor bugs
-
- * [381]20239 ICE on empty preprocessed input
- * [382]15220 "gcc -E -MM -MG" reports missing system headers in
- source directory
-
- Testsuite issues
-
- * [383]19275 gcc.dg/20020919-1.c fails with -fpic/-fPIC on
- i686-pc-linux-gnu
-
- Alpha specific
-
- * [384]21888 bootstrap failure with linker relaxation enabled
-
- ARM specific
-
- * [385]15342 [arm-linux]: ICE in verify_local_live_at_start
- * [386]23985 Memory aliasing information incorrect in inlined memcpy
-
- ColdFile specific
-
- * [387]16719 Illegal move of byte into address register causes
- compiler to ICE
-
- HPPA specific
-
- * [388]21723 ICE while building libgfortran
- * [389]21841 -mhp-ld/-mgnu-ld documentation
-
- IA-64 specific
-
- * [390]23644 IA-64 hardware models and configuration options
- documentation error
- * [391]24718 Shared libgcc not used for linking by default
-
- M68000 specific
-
- * [392]18421 ICE in reload_cse_simplify_operands, in postreload.c
-
- MIPS specific
-
- * [393]20621 ICE in change_address_1, in emit-rtl.c
-
- PowerPC and PowerPC64 specific
-
- * [394]18583 error on valid code: const
- __attribute__((altivec(vector__))) doesn't work in arrays
- * [395]20191 ICE in reload_cse_simplify_operands
- * [396]22083 AIX: TARGET_C99_FUNCTIONS is wrongly defined
- * [397]23070 CALL_V4_CLEAR_FP_ARGS flag not properly set
- * [398]23404 gij trashes args of functions with more than 8 fp args
- * [399]23539 C & C++ compiler generating misaligned references
- regardless of compiler flags
- * [400]24102 floatdisf2_internal2 broken
- * [401]24465 -mminimal-toc miscompilation of __thread vars
-
- Solaris specific
-
- * [402]19933 Problem with define of HUGE_VAL in math_c99
- * [403]21889 Native Solaris assembler cannot grok DTP-relative debug
- symbols
-
- SPARC specific
-
- * [404]19300 PCH failures on sparc-linux
- * [405]20301 Assembler labels have a leading "-"
- * [406]20673 C PCH testsuite assembly comparison failure
-
- x86 and x86_64 specific
-
- * [407]18582 ICE with arrays of type V2DF
- * [408]19340 Compilation SEGFAULTs with -O1 -fschedule-insns2
- -fsched2-use-traces
- * [409]21716 ICE in reg-stack.c's swap_rtx_condition
- * [410]24315 amd64 fails -fpeephole2
- __________________________________________________________________
-
-GCC 3.4.6
-
- This is the [411]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.4.6 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [412]GCC manuals. If that fails, the
- [413]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [414]gcc at gcc.gnu.org. All of [415]our lists have public
- archives.
-
- Copyright (C) [416]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [417]maintained by the GCC team. Last modified
- 2014-06-28[418].
-
-References
-
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- 329. https://gcc.gnu.org/PR18124
- 330. https://gcc.gnu.org/PR18155
- 331. https://gcc.gnu.org/PR18177
- 332. https://gcc.gnu.org/PR18368
- 333. https://gcc.gnu.org/PR18378
- 334. https://gcc.gnu.org/PR18466
- 335. https://gcc.gnu.org/PR18512
- 336. https://gcc.gnu.org/PR18545
- 337. https://gcc.gnu.org/PR18738
- 338. https://gcc.gnu.org/PR18803
- 339. https://gcc.gnu.org/PR19004
- 340. https://gcc.gnu.org/PR19208
- 341. https://gcc.gnu.org/PR19253
- 342. https://gcc.gnu.org/PR19608
- 343. https://gcc.gnu.org/PR19884
- 344. https://gcc.gnu.org/PR20153
- 345. https://gcc.gnu.org/PR20563
- 346. https://gcc.gnu.org/PR20789
- 347. https://gcc.gnu.org/PR21336
- 348. https://gcc.gnu.org/PR21768
- 349. https://gcc.gnu.org/PR21853
- 350. https://gcc.gnu.org/PR21903
- 351. https://gcc.gnu.org/PR21983
- 352. https://gcc.gnu.org/PR21987
- 353. https://gcc.gnu.org/PR22153
- 354. https://gcc.gnu.org/PR22172
- 355. https://gcc.gnu.org/PR21286
- 356. https://gcc.gnu.org/PR22233
- 357. https://gcc.gnu.org/PR22508
- 358. https://gcc.gnu.org/PR22545
- 359. https://gcc.gnu.org/PR23528
- 360. https://gcc.gnu.org/PR23550
- 361. https://gcc.gnu.org/PR23586
- 362. https://gcc.gnu.org/PR23624
- 363. https://gcc.gnu.org/PR23639
- 364. https://gcc.gnu.org/PR23797
- 365. https://gcc.gnu.org/PR23965
- 366. https://gcc.gnu.org/PR24052
- 367. https://gcc.gnu.org/PR24580
- 368. https://gcc.gnu.org/PR24267
- 369. https://gcc.gnu.org/PR17810
- 370. https://gcc.gnu.org/PR17860
- 371. https://gcc.gnu.org/PR21709
- 372. https://gcc.gnu.org/PR21964
- 373. https://gcc.gnu.org/PR22167
- 374. https://gcc.gnu.org/PR22619
- 375. https://gcc.gnu.org/PR23241
- 376. https://gcc.gnu.org/PR23478
- 377. https://gcc.gnu.org/PR24470
- 378. https://gcc.gnu.org/PR24950
- 379. https://gcc.gnu.org/PR14400
- 380. https://gcc.gnu.org/PR14940
- 381. https://gcc.gnu.org/PR20239
- 382. https://gcc.gnu.org/PR15220
- 383. https://gcc.gnu.org/PR19275
- 384. https://gcc.gnu.org/PR21888
- 385. https://gcc.gnu.org/PR15342
- 386. https://gcc.gnu.org/PR23985
- 387. https://gcc.gnu.org/PR16719
- 388. https://gcc.gnu.org/PR21723
- 389. https://gcc.gnu.org/PR21841
- 390. https://gcc.gnu.org/PR23644
- 391. https://gcc.gnu.org/PR24718
- 392. https://gcc.gnu.org/PR18421
- 393. https://gcc.gnu.org/PR20621
- 394. https://gcc.gnu.org/PR18583
- 395. https://gcc.gnu.org/PR20191
- 396. https://gcc.gnu.org/PR22083
- 397. https://gcc.gnu.org/PR23070
- 398. https://gcc.gnu.org/PR23404
- 399. https://gcc.gnu.org/PR23539
- 400. https://gcc.gnu.org/PR24102
- 401. https://gcc.gnu.org/PR24465
- 402. https://gcc.gnu.org/PR19933
- 403. https://gcc.gnu.org/PR21889
- 404. https://gcc.gnu.org/PR19300
- 405. https://gcc.gnu.org/PR20301
- 406. https://gcc.gnu.org/PR20673
- 407. https://gcc.gnu.org/PR18582
- 408. https://gcc.gnu.org/PR19340
- 409. https://gcc.gnu.org/PR21716
- 410. https://gcc.gnu.org/PR24315
- 411. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=3.4.6
- 412. https://gcc.gnu.org/onlinedocs/
- 413. mailto:gcc-help at gcc.gnu.org
- 414. mailto:gcc at gcc.gnu.org
- 415. https://gcc.gnu.org/lists.html
- 416. http://www.fsf.org/
- 417. https://gcc.gnu.org/about.html
- 418. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.3/index.html
- GCC 3.3 Release Series
-
- May 03, 2005
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 3.3.6.
-
- This release is a bug-fix release, containing fixes for regressions in
- GCC 3.3.5 relative to previous releases of GCC.
-
- This release is the last of the series 3.3.x.
-
- The GCC 3.3 release series includes numerous [2]new features,
- improvements, bug fixes, and other changes, thanks to an [3]amazing
- group of volunteers.
-
-Release History
-
- GCC 3.3.6
- May 3, 2005 ([4]changes)
-
- GCC 3.3.5
- September 30, 2004 ([5]changes)
-
- GCC 3.3.4
- May 31, 2004 ([6]changes)
-
- GCC 3.3.3
- February 14, 2004 ([7]changes)
-
- GCC 3.3.2
- October 16, 2003 ([8]changes)
-
- GCC 3.3.1
- August 8, 2003 ([9]changes)
-
- GCC 3.3
- May 14, 2003 ([10]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [11]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [12]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [13]GCC
- project web site or contact the [14]GCC development mailing list.
-
- To obtain GCC please use [15]our mirror sites, or our CVS server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [16]GCC manuals. If that fails, the
- [17]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [18]gcc at gcc.gnu.org. All of [19]our lists have public
- archives.
-
- Copyright (C) [20]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [21]maintained by the GCC team. Last modified
- 2014-06-28[22].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-3.3/changes.html
- 3. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 4. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.6
- 5. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.5
- 6. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.4
- 7. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.3
- 8. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.2
- 9. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.1
- 10. http://gcc.gnu.org/gcc-3.3/changes.html
- 11. http://gcc.gnu.org/gcc-3.3/buildstat.html
- 12. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 13. http://gcc.gnu.org/index.html
- 14. mailto:gcc at gcc.gnu.org
- 15. http://gcc.gnu.org/mirrors.html
- 16. https://gcc.gnu.org/onlinedocs/
- 17. mailto:gcc-help at gcc.gnu.org
- 18. mailto:gcc at gcc.gnu.org
- 19. https://gcc.gnu.org/lists.html
- 20. http://www.fsf.org/
- 21. https://gcc.gnu.org/about.html
- 22. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.3/changes.html
- GCC 3.3 Release Series
- Changes, New Features, and Fixes
-
- The latest release in the 3.3 release series is [1]GCC 3.3.6.
-
-Caveats
-
- * The preprocessor no longer accepts multi-line string literals. They
- were deprecated in 3.0, 3.1, and 3.2.
- * The preprocessor no longer supports the -A- switch when appearing
- alone. -A- followed by an assertion is still supported.
- * Support for all the systems [2]obsoleted in GCC 3.1 has been
- removed from GCC 3.3. See below for a [3]list of systems which are
- obsoleted in this release.
- * Checking for null format arguments has been decoupled from the rest
- of the format checking mechanism. Programs which use the format
- attribute may regain this functionality by using the new [4]nonnull
- function attribute. Note that all functions for which GCC has a
- built-in format attribute, an appropriate built-in nonnull
- attribute is also applied.
- * The DWARF (version 1) debugging format has been deprecated and will
- be removed in a future version of GCC. Version 2 of the DWARF
- debugging format will continue to be supported for the foreseeable
- future.
- * The C and Objective-C compilers no longer accept the "Naming Types"
- extension (typedef foo = bar); it was already unavailable in C++.
- Code which uses it will need to be changed to use the "typeof"
- extension instead: typedef typeof(bar) foo. (We have removed this
- extension without a period of deprecation because it has caused the
- compiler to crash since version 3.0 and no one noticed until very
- recently. Thus we conclude it is not in widespread use.)
- * The -traditional C compiler option has been removed. It was
- deprecated in 3.1 and 3.2. (Traditional preprocessing remains
- available.) The <varargs.h> header, used for writing variadic
- functions in traditional C, still exists but will produce an error
- message if used.
- * GCC 3.3.1 automatically places zero-initialized variables in the
- .bss section on some operating systems. Versions of GNU Emacs up to
- (and including) 21.3 will not work correctly when using this
- optimization; you can use -fno-zero-initialized-in-bss to disable
- it.
-
-General Optimizer Improvements
-
- * A new scheme for accurately describing processor pipelines, the
- [5]DFA scheduler, has been added.
- * Pavel Nejedly, Charles University Prague, has contributed new file
- format used by the edge coverage profiler (-fprofile-arcs).
- The new format is robust and diagnoses common mistakes where
- profiles from different versions (or compilations) of the program
- are combined resulting in nonsensical profiles and slow code to
- produced with profile feedback. Additionally this format allows
- extra data to be gathered. Currently, overall statistics are
- produced helping optimizers to identify hot spots of a program
- globally replacing the old intra-procedural scheme and resulting in
- better code. Note that the gcov tool from older GCC versions will
- not be able to parse the profiles generated by GCC 3.3 and vice
- versa.
- * Jan Hubicka, SuSE Labs, has contributed a new superblock formation
- pass enabled using -ftracer. This pass simplifies the control flow
- of functions allowing other optimizations to do better job.
- He also contributed the function reordering pass
- (-freorder-functions) to optimize function placement using profile
- feedback.
-
-New Languages and Language specific improvements
-
- C/ObjC/C++
-
- * The preprocessor now accepts directives within macro arguments. It
- processes them just as if they had not been within macro arguments.
- * The separate ISO and traditional preprocessors have been completely
- removed. The front end handles either type of preprocessed output
- if necessary.
- * In C99 mode preprocessor arithmetic is done in the precision of the
- target's intmax_t, as required by that standard.
- * The preprocessor can now copy comments inside macros to the output
- file when the macro is expanded. This feature, enabled using the
- -CC option, is intended for use by applications which place
- metadata or directives inside comments, such as lint.
- * The method of constructing the list of directories to be searched
- for header files has been revised. If a directory named by a -I
- option is a standard system include directory, the option is
- ignored to ensure that the default search order for system
- directories and the special treatment of system header files are
- not defeated.
- * A few more [6]ISO C99 features now work correctly.
- * A new function attribute, nonnull, has been added which allows
- pointer arguments to functions to be specified as requiring a
- non-null value. The compiler currently uses this information to
- issue a warning when it detects a null value passed in such an
- argument slot.
- * A new type attribute, may_alias, has been added. Accesses to
- objects with types with this attribute are not subjected to
- type-based alias analysis, but are instead assumed to be able to
- alias any other type of objects, just like the char type.
-
- C++
-
- * Type based alias analysis has been implemented for C++ aggregate
- types.
-
- Objective-C
-
- * Generate an error if Objective-C objects are passed by value in
- function and method calls.
- * When -Wselector is used, check the whole list of selectors at the
- end of compilation, and emit a warning if a @selector() is not
- known.
- * Define __NEXT_RUNTIME__ when compiling for the NeXT runtime.
- * No longer need to include objc/objc-class.h to compile self calls
- in class methods (NeXT runtime only).
- * New -Wundeclared-selector option.
- * Removed selector bloating which was causing object files to be 10%
- bigger on average (GNU runtime only).
- * Using at run time @protocol() objects has been fixed in certain
- situations (GNU runtime only).
- * Type checking has been fixed and improved in many situations
- involving protocols.
-
- Java
-
- * The java.sql and javax.sql packages now implement the JDBC 3.0 (JDK
- 1.4) API.
- * The JDK 1.4 assert facility has been implemented.
- * The bytecode interpreter is now direct threaded and thus faster.
-
- Fortran
-
- * Fortran improvements are listed in [7]the Fortran documentation.
-
- Ada
-
- * Ada tasking now works with glibc 2.3.x threading libraries.
-
-New Targets and Target Specific Improvements
-
- * The following changes have been made to the HP-PA port:
- + The port now defaults to scheduling for the PA8000 series of
- processors.
- + Scheduling support for the PA7300 processor has been added.
- + The 32-bit port now supports weak symbols under HP-UX 11.
- + The handling of initializers and finalizers has been improved
- under HP-UX 11. The 64-bit port no longer uses collect2.
- + Dwarf2 EH support has been added to the 32-bit GNU/Linux port.
- + ABI fixes to correct the passing of small structures by value.
- * The SPARC, HP-PA, SH4, and x86/pentium ports have been converted to
- use the DFA processor pipeline description.
- * The following NetBSD configurations for the SuperH processor family
- have been added:
- + SH3, big-endian, sh-*-netbsdelf*
- + SH3, little-endian, shle-*-netbsdelf*
- + SH5, SHmedia, big-endian, 32-bit default, sh5-*-netbsd*
- + SH5, SHmedia, little-endian, 32-bit default, sh5le-*-netbsd*
- + SH5, SHmedia, big-endian, 64-bit default, sh64-*-netbsd*
- + SH5, SHmedia, little-endian, 64-bit default, sh64le-*-netbsd*
- * The following changes have been made to the IA-32/x86-64 port:
- + SSE2 and 3dNOW! intrinsics are now supported.
- + Support for thread local storage has been added to the IA-32
- and x86-64 ports.
- + The x86-64 port has been significantly improved.
- * The following changes have been made to the MIPS port:
- + All configurations now accept the -mabi switch. Note that you
- will need appropriate multilibs for this option to work
- properly.
- + ELF configurations will always pass an ABI flag to the
- assembler, except when the MIPS EABI is selected.
- + -mabi=64 no longer selects MIPS IV code.
- + The -mcpu option, which was deprecated in 3.1 and 3.2, has
- been removed from this release.
- + -march now changes the core ISA level. In previous releases,
- it would change the use of processor-specific extensions, but
- would leave the core ISA unchanged. For example, mips64-elf
- -march=r8000 will now generate MIPS IV code.
- + Under most configurations, -mipsN now acts as a synonym for
- -march.
- + There are some new preprocessor macros to describe the -march
- and -mtune settings. See the documentation of those options
- for details.
- + Support for the NEC VR-Series processors has been added. This
- includes the 54xx, 5500, and 41xx series.
- + Support for the Sandcraft sr71k processor has been added.
- * The following changes have been made to the S/390 port:
- + Support to build the Java runtime libraries has been added.
- Java is now enabled by default on s390-*-linux* and
- s390x-*-linux* targets.
- + Multilib support for the s390x-*-linux* target has been added;
- this allows to build 31-bit binaries using the -m31 option.
- + Support for thread local storage has been added.
- + Inline assembler code may now use the 'Q' constraint to
- specify memory operands without index register.
- + Various platform-specific performance improvements have been
- implemented; in particular, the compiler now uses the BRANCH
- ON COUNT family of instructions and makes more frequent use of
- the TEST UNDER MASK family of instructions.
- * The following changes have been made to the PowerPC port:
- + Support for IBM Power4 processor added.
- + Support for Motorola e500 SPE added.
- + Support for AIX 5.2 added.
- + Function and Data sections now supported on AIX.
- + Sibcall optimizations added.
- * The support for H8 Tiny is added to the H8/300 port with -mn.
-
-Obsolete Systems
-
- Support for a number of older systems has been declared obsolete in GCC
- 3.3. Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
-
- All configurations of the following processor architectures have been
- declared obsolete:
- * Matsushita MN10200, mn10200-*-*
- * Motorola 88000, m88k-*-*
- * IBM ROMP, romp-*-*
-
- Also, some individual systems have been obsoleted:
- * Alpha
- + Interix, alpha*-*-interix*
- + Linux libc1, alpha*-*-linux*libc1*
- + Linux ECOFF, alpha*-*-linux*ecoff*
- * ARM
- + Generic a.out, arm*-*-aout*
- + Conix, arm*-*-conix*
- + "Old ABI," arm*-*-oabi
- + StrongARM/COFF, strongarm-*-coff*
- * HPPA (PA-RISC)
- + Generic OSF, hppa1.0-*-osf*
- + Generic BSD, hppa1.0-*-bsd*
- + HP/UX versions 7, 8, and 9, hppa1.[01]-*-hpux[789]*
- + HiUX, hppa*-*-hiux*
- + Mach Lites, hppa*-*-lites*
- * Intel 386 family
- + Windows NT 3.x, i?86-*-win32
- * MC68000 family
- + HP systems, m68000-hp-bsd* and m68k-hp-bsd*
- + Sun systems, m68000-sun-sunos*, m68k-sun-sunos*, and
- m68k-sun-mach*
- + AT&T systems, m68000-att-sysv*
- + Atari systems, m68k-atari-sysv*
- + Motorola systems, m68k-motorola-sysv*
- + NCR systems, m68k-ncr-sysv*
- + Plexus systems, m68k-plexus-sysv*
- + Commodore systems, m68k-cbm-sysv*
- + Citicorp TTI, m68k-tti-*
- + Unos, m68k-crds-unos*
- + Concurrent RTU, m68k-ccur-rtu*
- + Linux a.out, m68k-*-linux*aout*
- + Linux libc1, m68k-*-linux*libc1*
- + pSOS, m68k-*-psos*
- * MIPS
- + Generic ECOFF, mips*-*-ecoff*
- + SINIX, mips-sni-sysv4
- + Orion RTEMS, mips64orion-*-rtems*
- * National Semiconductor 32000
- + OpenBSD, ns32k-*-openbsd*
- * POWER (aka RS/6000) and PowerPC
- + AIX versions 1, 2, and 3, rs6000-ibm-aix[123]*
- + Bull BOSX, rs6000-bull-bosx
- + Generic Mach, rs6000-*-mach*
- + Generic SysV, powerpc*-*-sysv*
- + Linux libc1, powerpc*-*-linux*libc1*
- * Sun SPARC
- + Generic a.out, sparc-*-aout*, sparclet-*-aout*,
- sparclite-*-aout*, and sparc86x-*-aout*
- + NetBSD a.out, sparc-*-netbsd*aout*
- + Generic BSD, sparc-*-bsd*
- + ChorusOS, sparc-*-chorusos*
- + Linux a.out, sparc-*-linux*aout*
- + Linux libc1, sparc-*-linux*libc1*
- + LynxOS, sparc-*-lynxos*
- + Solaris on HAL hardware, sparc-hal-solaris2*
- + SunOS versions 3 and 4, sparc-*-sunos[34]*
- * NEC V850
- + RTEMS, v850-*-rtems*
- * VAX
- + VMS, vax-*-vms*
-
-Documentation improvements
-
-Other significant improvements
-
- * Almost all front-end dependencies in the compiler have been
- separated out into a set of language hooks. This should make adding
- a new front end clearer and easier.
- * One effect of removing the separate preprocessor is a small
- increase in the robustness of the compiler in general, and the
- maintainability of target descriptions. Previously target-specific
- built-in macros and others, such as __FAST_MATH__, had to be
- handled with so-called specs that were hard to maintain. Often they
- would fail to behave properly when conflicting options were
- supplied on the command line, and define macros in the user's
- namespace even when strict ISO compliance was requested.
- Integrating the preprocessor has cleanly solved these issues.
- * The Makefile suite now supports redirection of make install by
- means of the variable DESTDIR.
- __________________________________________________________________
-
-GCC 3.3
-
- Detailed release notes for the GCC 3.3 release follow.
-
- Bug Fixes
-
- bootstrap failures
-
- * [8]10140 cross compiler build failures: missing __mempcpy (DUP:
- [9]10198,[10]10338)
-
- Internal compiler errors (multi-platform)
-
- * [11]3581 large string causes segmentation fault in cc1
- * [12]4382 __builtin_{set,long}jmp with -O3 can crash the compiler
- * [13]5533 (c++) ICE when processing std::accumulate(begin, end,
- init, invalid_op)
- * [14]6387 -fpic -gdwarf-2 -g1 combination gives ICE in dwarf2out
- * [15]6412 (c++) ICE in retrieve_specialization
- * [16]6620 (c++) partial template specialization causes an ICE
- (segmentation fault)
- * [17]6663 (c++) ICE with attribute aligned
- * [18]7068 ICE with incomplete types
- * [19]7083 (c++) ICE using -gstabs with dodgy class derivation
- * [20]7647 (c++) ICE when data member has the name of the enclosing
- class
- * [21]7675 ICE in fixup_var_refs_1
- * [22]7718 'complex' template instantiation causes ICE
- * [23]8116 (c++) ICE in member template function
- * [24]8358 (ada) Ada compiler accesses freed memory, crashes
- * [25]8511 (c++) ICE: (hopefully) reproducible cc1plus segmentation
- fault
- * [26]8564 (c++) ICE in find_function_data, in function.c
- * [27]8660 (c++) template overloading ICE in tsubst_expr, in cp/pt.c
- * [28]8766 (c++) ICE after failed initialization of static template
- variable
- * [29]8803 ICE in instantiate_virtual_regs_1, in function.c
- * [30]8846 (c++) ICE after diagnostic if fr_FR at euro locale is set
- * [31]8906 (c++) ICE (Segmentation fault) when parsing nested-class
- definition
- * [32]9216 (c++) ICE on missing template parameter
- * [33]9261 (c++) ICE in arg_assoc, in cp/decl2.c
- * [34]9263 (fortran) ICE caused by invalid PARAMETER in implied DO
- loop
- * [35]9429 (c++) ICE in template instantiation with a pointered new
- operator
- * [36]9516 Internal error when using a big array
- * [37]9600 (c++) ICE with typedefs in template class
- * [38]9629 (c++) virtual inheritance segfault
- * [39]9672 (c++) ICE: Error reporting routines re-entered
- * [40]9749 (c++) ICE in write_expression on invalid function
- prototype
- * [41]9794 (fortran) ICE: floating point exception during constant
- folding
- * [42]9829 (c++) Missing colon in nested namespace usage causes ICE
- * [43]9916 (c++) ICE with noreturn function in ?: statement
- * [44]9936 ICE with local function and variable-length 2d array
- * [45]10262 (c++) cc1plus crashes with large generated code
- * [46]10278 (c++) ICE in parser for invalid code
- * [47]10446 (c++) ICE on definition of nonexistent member function of
- nested class in a class template
- * [48]10451 (c++) ICE in grokdeclarator on spurious mutable
- declaration
- * [49]10506 (c++) ICE in build_new at cp/init.c with
- -fkeep-inline-functions and multiple inheritance
- * [50]10549 (c++) ICE in store_bit_field on bitfields that exceed the
- precision of the declared type
-
- Optimization bugs
-
- * [51]2001 Inordinately long compile times in reload CSE regs
- * [52]2391 Exponential compilation time explosion in combine
- * [53]2960 Duplicate loop conditions even with -Os
- * [54]4046 redundant conditional branch
- * [55]6405 Loop-unrolling related performance regressions
- * [56]6798 very long compile time with large case-statement
- * [57]6871 const objects shouldn't be moved to .bss
- * [58]6909 problem w/ -Os on modified loop-2c.c test case
- * [59]7189 gcc -O2 -Wall does not print ``control reaches end of
- non-void function'' warning
- * [60]7642 optimization problem with signbit()
- * [61]8634 incorrect code for inlining of memcpy under -O2
- * [62]8750 Cygwin prolog generation erroneously emitting __alloca as
- regular function call
-
- C front end
-
- * [63]2161 long if-else cascade overflows parser stack
- * [64]4319 short accepted on typedef'd char
- * [65]8602 incorrect line numbers in warning messages when using
- inline functions
- * [66]9177 -fdump-translation-unit: C front end deletes function_decl
- AST nodes and breaks debugging dumps
- * [67]9853 miscompilation of non-constant structure initializer
-
- c++ compiler and library
-
- * [68]45 legal template specialization code is rejected (DUP:
- [69]3784)
- * [70]764 lookup failure: friend operator and dereferencing a pointer
- and templates (DUP: [71]5116)
- * [72]2862 gcc accepts invalid explicit instantiation syntax (DUP:
- 2863)
- * [73]3663 G++ doesn't check access control during template
- instantiation
- * [74]3797 gcc fails to emit explicit specialization of a template
- member
- * [75]3948 Two destructors are called when no copy destructor is
- defined (ABI change)
- * [76]4137 Conversion operator within template is not accepted
- * [77]4361 bogus ambiguity taking the address of a member template
- * [78]4802 g++ accepts illegal template code (access to private
- member; DUP: [79]5837)
- * [80]4803 inline function is used but never defined, and g++ does
- not object
- * [81]5094 Partial specialization cannot be friend?
- * [82]5730 complex<double>::norm() -- huge slowdown from egcs-2.91.66
- * [83]6713 Regression wrt 3.0.4: g++ -O2 leads to seg fault at run
- time
- * [84]7015 certain __asm__ constructs rejected
- * [85]7086 compile time regression (quadratic behavior in
- fixup_var_refs)
- * [86]7099 G++ doesn't set the noreturn attribute on std::exit and
- std::abort
- * [87]7247 copy constructor missing when inlining enabled (invalid
- optimization?)
- * [88]7441 string array initialization compilation time regression
- from seconds to minutes
- * [89]7768 __PRETTY_FUNCTION__ for template destructor is wrong
- * [90]7804 bad printing of floating point constant in warning message
- * [91]8099 Friend classes and template specializations
- * [92]8117 member function pointers and multiple inheritance
- * [93]8205 using declaration and multiple inheritance
- * [94]8645 unnecessary non-zero checks in stl_tree.h
- * [95]8724 explicit destructor call for incomplete class allowed
- * [96]8805 compile time regression with many member variables
- * [97]8691 -O3 and -fno-implicit-templates are incompatible
- * [98]8700 unhelpful error message for binding temp to reference
- * [99]8724 explicit destructor call for incomplete class allowed
- * [100]8949 numeric_limits<>::denorm_min() and is_iec559 problems
- * [101]9016 Failure to consistently constant fold "constant" C++
- objects
- * [102]9053 g++ confused about ambiguity of overloaded function
- templates
- * [103]9152 undefined virtual thunks
- * [104]9182 basic_filebuf<> does not report errors in codecvt<>::out
- * [105]9297 data corruption due to codegen bug (when copying.)
- * [106]9318 i/ostream::operator>>/<<(streambuf*) broken
- * [107]9320 Incorrect usage of traits_type::int_type in stdio_filebuf
- * [108]9400 bogus -Wshadow warning: shadowed declaration of this in
- local classes
- * [109]9424 i/ostream::operator>>/<<(streambuf*) drops characters
- * [110]9425 filebuf::pbackfail broken (DUP: [111]9439)
- * [112]9474 GCC freezes in compiling a weird code mixing <iostream>
- and <iostream.h>
- * [113]9548 Incorrect results from setf(ios::fixed) and precision(-1)
- [114][DR 231]
- * [115]9555 ostream inserters fail to set badbit on exception
- * [116]9561 ostream inserters rethrow exception of wrong type
- * [117]9563 ostream::sentry returns true after a failed preparation
- * [118]9582 one-definition rule violation in std::allocator
- * [119]9622 __PRETTY_FUNCTION__ incorrect in template destructors
- * [120]9683 bug in initialization chains for static const variables
- from template classes
- * [121]9791 -Woverloaded-virtual reports hiding of destructor
- * [122]9817 collate::compare doesn't handle nul characters
- * [123]9825 filebuf::sputbackc breaks sbumpc
- * [124]9826 operator>>(basic_istream, basic_string) fails to compile
- with custom traits
- * [125]9924 Multiple using statements for builtin functions not
- allowed
- * [126]9946 destructor is not called for temporary object
- * [127]9964 filebuf::close() sometimes fails to close file
- * [128]9988 filebuf::overflow writes EOF to file
- * [129]10033 optimization breaks polymorphic references w/ typeid
- operator
- * [130]10097 filebuf::underflow drops characters
- * [131]10132 filebuf destructor can throw exceptions
- * [132]10180 gcc fails to warn about non-inlined function
- * [133]10199 method parametrized by template does not work everywhere
- * [134]10300 use of array-new (nothrow) in segfaults on NULL return
- * [135]10427 Stack corruption with variable-length automatic arrays
- and virtual destructors
- * [136]10503 Compilation never stops in fixed_type_or_null
-
- Objective-C
-
- * [137]5956 selectors aren't matched properly when added to the
- selector table
-
- Fortran compiler and library
-
- * [138]1832 list directed i/o overflow hangs, -fbounds-check doesn't
- detect
- * [139]3924 g77 generates code that is rejected by GAS if COFF debug
- info requested
- * [140]5634 doc: explain that configure --prefix=~/... does not work
- * [141]6367 multiple repeat counts confuse namelist read into array
- * [142]6491 Logical operations error on logicals when using
- -fugly-logint
- * [143]6742 Generation of C++ Prototype for FORTRAN and extern "C"
- * [144]7113 Failure of g77.f-torture/execute/f90-intrinsic-bit.f -Os
- on irix6.5
- * [145]7236 OPEN(...,RECL=nnn,...) without ACCESS='DIRECT' should
- assume a direct access file
- * [146]7278 g77 "bug"; the executable misbehaves (with -O2
- -fno-automatic)
- * [147]7384 DATE_AND_TIME milliseconds field inactive on Windows
- * [148]7388 Incorrect output with 0-based array of characters
- * [149]8587 Double complex zero ** double precision number -> NaN
- instead of zero
- * [150]9038 -ffixed-line-length-none -x f77-cpp-input gives: Warning:
- unknown register name line-length-none
- * [151]10197 Direct access files not unformatted by default
-
- Java compiler and library
-
- * [152]6005 gcj fails to build rhug on alpha
- * [153]6389 System.getProperty("") should always throw an
- IllegalArgumentException
- * [154]6576 java.util.ResourceBundle.getResource ignores locale
- * [155]6652 new java.io.File("").getCanonicalFile() throws exception
- * [156]7060 getMethod() doesn't search super interface
- * [157]7073 bytecode interpreter gives wrong answer for interface
- getSuperclass()
- * [158]7180 possible bug in
- javax.naming.spi.NamingManager.getPlusPath()
- * [159]7416 java.security startup refs "GNU libgcj.security"
- * [160]7570 Runtime.exec with null envp: child doesn't inherit parent
- env (DUP: [161]7578)
- * [162]7611 Internal error while compiling libjava with -O
- * [163]7709 NullPointerException in _Jv_ResolvePoolEntry
- * [164]7766 ZipInputStream.available returns 0 immediately after
- construction
- * [165]7785 Calendar.getTimeInMillis/setTimeInMillis should be public
- * [166]7786 TimeZone.getDSTSavings() from JDK1.4 not implemented
- * [167]8142 '$' in class names vs. dlopen 'dynamic string tokens'
- * [168]8234 ZipInputStream chokes when InputStream.read() returns
- small chunks
- * [169]8415 reflection bug: exception info for Method
- * [170]8481 java.Random.nextInt(int) may return negative
- * [171]8593 Error reading GZIPped files with BufferedReader
- * [172]8759 java.beans.Introspector has no flushCaches() or
- flushFromCaches() methods
- * [173]8997 spin() calls Thread.sleep
- * [174]9253 on win32, java.io.File.listFiles("C:\\") returns pwd
- instead of the root content of C:
- * [175]9254 java::lang::Object::wait(), threads-win32.cc returns
- wrong return codes
- * [176]9271 Severe bias in java.security.SecureRandom
-
- Ada compiler and library
-
- * [177]6767 make gnatlib-shared fails on -laddr2line
- * [178]9911 gnatmake fails to link when GCC configured with
- --with-sjlj-exceptions=yes
- * [179]10020 Can't bootstrap gcc on AIX with Ada enabled
- * [180]10546 Ada tasking not working on Red Hat 9
-
- preprocessor
-
- * [181]7029 preprocessor should ignore #warning with -M
-
- ARM-specific
-
- * [182]2903 [arm] Optimization bug with long long arithmetic
- * [183]7873 arm-linux-gcc fails when assigning address to a bit field
-
- FreeBSD-specific
-
- * [184]7680 float functions undefined in math.h/cmath with #define
- _XOPEN_SOURCE
-
- HP-UX or HP-PA-specific
-
- * [185]8705 [HP-PA] ICE in emit_move_insn_1, in expr.c
- * [186]9986 [HP-UX] Incorrect transformation of fputs_unlocked to
- fputc_unlocked
- * [187]10056 [HP-PA] ICE at -O2 when building c++ code from doxygen
-
- m68hc11-specific
-
- * [188]6744 Bad assembler code generated: reference to pseudo
- register z
- * [189]7361 Internal compiler error in reload_cse_simplify_operands,
- in reload1.c
-
- MIPS-specific
-
- * [190]9496 [mips-linux] bug in optimizer?
-
- PowerPC-specific
-
- * [191]7067 -Os with -mcpu=powerpc optimizes for speed (?) instead of
- space
- * [192]8480 reload ICEs for LAPACK code on powerpc64-linux
- * [193]8784 [AIX] Internal compiler error in simplify_gen_subreg
- * [194]10315 [powerpc] ICE: in extract_insn, in recog.c
-
- SPARC-specific
-
- * [195]10267 (documentation) Wrong build instructions for
- *-*-solaris2*
-
- x86-specific (Intel/AMD)
-
- * [196]7916 ICE in instantiate_virtual_register_1
- * [197]7926 (c++) i486 instructions in header files make c++ programs
- crash on i386
- * [198]8555 ICE in gen_split_1231
- * [199]8994 ICE with -O -march=pentium4
- * [200]9426 ICE with -fssa -funroll-loops -fprofile-arcs
- * [201]9806 ICE in inline assembly with -fPIC flag
- * [202]10077 gcc -msse2 generates movd to move dwords between xmm
- regs
- * [203]10233 64-bit comparison only comparing bottom 32-bits
- * [204]10286 type-punning doesn't work with __m64 and -O
- * [205]10308 [x86] ICE with -O -fgcse or -O2
- __________________________________________________________________
-
-GCC 3.3.1
-
- Bug Fixes
-
- This section lists the problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.3.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
- Bootstrap failures
-
- * [206]11272 [Solaris] make bootstrap fails while building libstdc++
-
- Internal compiler errors (multi-platform)
-
- * [207]5754 ICE on invalid nested template class
- * [208]6597 ICE in set_mem_alias_set compiling Qt with -O2 on ia64
- and --enable-checking
- * [209]6949 (c++) ICE in tsubst_decl, in cp/pt.c
- * [210]7053 (c++) ICE when declaring a function already defined as a
- friend method of a template class
- * [211]8164 (c++) ICE when using different const expressions as
- template parameter
- * [212]8384 (c++) ICE in is_base_type, in dwarf2out.c
- * [213]9559 (c++) ICE with invalid initialization of a static const
- * [214]9649 (c++) ICE in finish_member_declaration, in cp/semantics.c
- when redeclaring a static member variable
- * [215]9864 (fortran) ICE in add_abstract_origin_attribute, in
- dwarfout.c with -g -O -finline-functions
- * [216]10432 (c++) ICE in poplevel, in cp/decl.c
- * [217]10475 ICE in subreg_highpart_offset for code with long long
- * [218]10635 (c++) ICE when dereferencing an incomplete type casted
- from a void pointer
- * [219]10661 (c++) ICE in instantiate_decl, in cp/pt.c while
- instantiating static member variables
- * [220]10700 ICE in copy_to_mode_reg on 64-bit targets
- * [221]10712 (c++) ICE in constructor_name_full, in cp/decl2.c
- * [222]10796 (c++) ICE when defining an enum with two values: -1 and
- MAX_INT_64BIT
- * [223]10890 ICE in merge_assigned_reloads building Linux 2.4.2x
- sched.c
- * [224]10939 (c++) ICE with template code
- * [225]10956 (c++) ICE when specializing a template member function
- of a template class, in tsubst, in cp/pt.c
- * [226]11041 (c++) ICE: const myclass &x = *x; (when operator*()
- defined)
- * [227]11059 (c++) ICE with empty union
- * [228]11083 (c++) ICE in commit_one_edge_insertion, in cfgrtl.c with
- -O2 -fnon-call-exceptions
- * [229]11105 (c++) ICE in mangle_conv_op_name_for_type
- * [230]11149 (c++) ICE on error when instantiation with call function
- of a base type
- * [231]11228 (c++) ICE on new-expression using array operator new and
- default-initialization
- * [232]11282 (c++) Infinite memory usage after syntax error
- * [233]11301 (fortran) ICE with -fno-globals
- * [234]11308 (c++) ICE when using an enum type name as if it were a
- class or namespace
- * [235]11473 (c++) ICE with -gstabs when empty struct inherits from
- an empty struct
- * [236]11503 (c++) ICE when instantiating template with ADDR_EXPR
- * [237]11513 (c++) ICE in push_template_decl_real, in cp/pt.c:
- template member functions
-
- Optimization bugs
-
- * [238]11198 -O2 -frename-registers generates wrong code (aliasing
- problem)
- * [239]11304 Wrong code production with -fomit-frame-pointer
- * [240]11381 volatile memory access optimized away
- * [241]11536 [strength-reduce] -O2 optimization produces wrong code
- * [242]11557 constant folding bug generates wrong code
-
- C front end
-
- * [243]5897 No warning for statement after return
- * [244]11279 DWARF-2 output mishandles large enums
-
- Preprocessor bugs
-
- * [245]11022 no warning for non-compatible macro redefinition
-
- C++ compiler and library
-
- * [246]2330 static_cast<>() to a private base is allowed
- * [247]5388 Incorrect message "operands to ?: have different types"
- * [248]5390 Libiberty fails to demangle multi-digit template
- parameters
- * [249]7877 Incorrect parameter passing to specializations of member
- function templates
- * [250]9393 Anonymous namespaces and compiling the same file twice
- * [251]10032 -pedantic converts some errors to warnings
- * [252]10468 const typeof(x) is non-const, but only in templates
- * [253]10527 confused error message with "new int()" parameter
- initializer
- * [254]10679 parameter MIN_INLINE_INSNS is not honored
- * [255]10682 gcc chokes on a typedef for an enum inside a class
- template
- * [256]10689 pow(std::complex(0),1/3) returns (nan, nan) instead of
- 0.
- * [257]10845 template member function (with nested template as
- parameter) cannot be called anymore if another unrelated template
- member function is defined
- * [258]10849 Cannot define an out-of-class specialization of a
- private nested template class
- * [259]10888 Suppress -Winline warnings for system headers
- * [260]10929 -Winline warns about functions for which no definition
- is visible
- * [261]10931 valid conversion static_cast<const unsigned
- int&>(lvalue-of-type-int) is rejected
- * [262]10940 Bad code with explicit specialization
- * [263]10968 If member function implicitly instantiated, explicit
- instantiation of class fails to instantiate it
- * [264]10990 Cannot convert with dynamic_cast<> to a private base
- class from within a member function
- * [265]11039 Bad interaction between implicit typename deprecation
- and friendship
- * [266]11062 (libstdc++) avoid __attribute__ ((unused)); say
- "__unused__" instead
- * [267]11095 C++ iostream manipulator causes segfault when called
- with negative argument
- * [268]11098 g++ doesn't emit complete debugging information for
- local variables in destructors
- * [269]11137 GNU/Linux shared library constructors not called unless
- there's one global object
- * [270]11154 spurious ambiguity report for template class
- specialization
- * [271]11329 Compiler cannot find user defined implicit typecast
- * [272]11332 Spurious error with casts in ?: expression
- * [273]11431 static_cast behavior with subclasses when default
- constructor available
- * [274]11528 money_get facet does not accept "$.00" as valid
- * [275]11546 Type lookup problems in out-of-line definition of a
- class doubly nested from a template class
- * [276]11567 C++ code containing templated member function with same
- name as pure virtual member function results in linking failure
- * [277]11645 Failure to deal with using and private inheritance
-
- Java compiler and library
-
- * [278]5179 Qualified static field access doesn't initialize its
- class
- * [279]8204 gcj -O2 to native reorders certain instructions
- improperly
- * [280]10838 java.io.ObjectInputStream syntax error
- * [281]10886 The RMI registry that comes with GCJ does not work
- correctly
- * [282]11349 JNDI URL context factories not located correctly
-
- x86-specific (Intel/AMD)
-
- * [283]4823 ICE on inline assembly code
- * [284]8878 miscompilation with -O and SSE
- * [285]9815 (c++ library) atomicity.h - fails to compile with -O3
- -masm=intel
- * [286]10402 (inline assembly) [x86] ICE in merge_assigned_reloads,
- in reload1.c
- * [287]10504 ICE with SSE2 code and -O3 -mcpu=pentium4 -msse2
- * [288]10673 ICE for x86-64 on freebsd libc vfprintf.c source
- * [289]11044 [x86] out of range loop instructions for FP code on K6
- * [290]11089 ICE: instantiate_virtual_regs_lossage while using SSE
- built-ins
- * [291]11420 [x86_64] gcc generates invalid asm code when "-O -fPIC"
- is used
-
- SPARC- or Solaris- specific
-
- * [292]9362 solaris 'as' dies when fed .s and "-gstabs"
- * [293]10142 [SPARC64] gcc produces wrong code when passing
- structures by value
- * [294]10663 New configure check aborts with Sun tools.
- * [295]10835 combinatorial explosion in scheduler on HyperSPARC
- * [296]10876 ICE in calculate_giv_inc when building KDE
- * [297]10955 wrong code at -O3 for structure argument in context of
- structure return
- * [298]11018 -mcpu=ultrasparc busts tar-1.13.25
- * [299]11556 [sparc64] ICE in gen_reg_rtx() while compiling 2.6.x
- Linux kernel
-
- ia64 specific
-
- * [300]10907 gcc violates the ia64 ABI (GP must be preserved)
- * [301]11320 scheduler bug (in machine depended reorganization pass)
- * [302]11599 bug with conditional and __builtin_prefetch
-
- PowerPC specific
-
- * [303]9745 [powerpc] gcc mis-compiles libmcrypt (alias problem
- during loop)
- * [304]10871 error in rs6000_stack_info save_size computation
- * [305]11440 gcc mis-compiles c++ code (libkhtml) with -O2, -fno-gcse
- cures it
-
- m68k-specific
-
- * [306]7594 [m68k] ICE on legal code associated with simplify-rtx
- * [307]10557 [m68k] ICE in subreg_offset_representable_p
- * [308]11054 [m68k] ICE in reg_overlap_mentioned_p
-
- ARM-specific
-
- * [309]10834 [arm] GCC 3.3 still generates incorrect instructions for
- functions with __attribute__ ((interrupt ("IRQ")))
- * [310]10842 [arm] Clobbered link register is copied to pc under
- certain circumstances
- * [311]11052 [arm] noce_process_if_block() can lose REG_INC notes
- * [312]11183 [arm] ICE in change_address_1 (3.3) / subreg_hard_regno
- (3.4)
-
- MIPS-specific
-
- * [313]11084 ICE in propagate_one_insn, in flow.c
-
- SH-specific
-
- * [314]10331 can't compile c++ part of gcc cross compiler for sh-elf
- * [315]10413 [SH] ICE in reload_cse_simplify_operands, in reload1.c
- * [316]11096 i686-linux to sh-linux cross compiler fails to compile
- C++ files
-
- GNU/Linux (or Hurd?) specific
-
- * [317]2873 Bogus fixinclude of stdio.h from glibc 2.2.3
-
- UnixWare specific
-
- * [318]3163 configure bug: gcc/aclocal.m4 mmap test fails on UnixWare
- 7.1.1
-
- Cygwin (or mingw) specific
-
- * [319]5287 ICE with dllimport attribute
- * [320]10148 [MingW/CygWin] Compiler dumps core
-
- DJGPP specific
-
- * [321]8787 GCC fails to emit .intel_syntax when invoked with
- -masm=intel on DJGPP
-
- Darwin (and MacOS X) specific
-
- * [322]10900 trampolines crash
-
- Documentation
-
- * [323]1607 (c++) Format attributes on methods undocumented
- * [324]4252 Invalid option `-fdump-translation-unit'
- * [325]4490 Clarify restrictions on -m96bit-long-double,
- -m128bit-long-double
- * [326]10355 document an issue with regparm attribute on some systems
- (e.g. Solaris)
- * [327]10726 (fortran) Documentation for function "IDate Intrinsic
- (Unix)" is wrong
- * [328]10805 document bug in old version of Sun assembler
- * [329]10815 warn against GNU binutils on AIX
- * [330]10877 document need for newer binutils on i?86-*-linux-gnu
- * [331]11280 Manual incorrect with respect to -freorder-blocks
- * [332]11466 Document -mlittle-endian and its restrictions for the
- sparc64 port
-
- Testsuite bugs (compiler itself is not affected)
-
- * [333]10737 newer bison causes g++.dg/parse/crash2.C to incorrectly
- report failure
- * [334]10810 gcc-3.3 fails make check: buffer overrun in
- test_demangle.c
- __________________________________________________________________
-
-GCC 3.3.2
-
- Bug Fixes
-
- This section lists the problem reports (PRs) from GCC's bug tracker
- that are known to be fixed in the 3.3.2 release. This list might not be
- complete (that is, it is possible that some PRs that have been fixed
- are not listed here).
-
- Bootstrap failures and problems
-
- * [335]8336 [SCO5] bootstrap config still tries to use COFF options
- * [336]9330 [alpha-osf] Bootstrap failure on Compaq Tru64 with
- --enable-threads=posix
- * [337]9631 [hppa64-linux] gcc-3.3 fails to bootstrap
- * [338]9877 fixincludes makes a bad sys/byteorder.h on svr5 (UnixWare
- 7.1.1)
- * [339]11687 xstormy16-elf build fails in libf2c
- * [340]12263 [SGI IRIX] bootstrap fails during compile of
- libf2c/libI77/backspace.c
- * [341]12490 buffer overflow in scan-decls.c (during Solaris 9
- fix-header processing)
-
- Internal compiler errors (multi-platform)
-
- * [342]7277 Casting integers to vector types causes ICE
- * [343]7939 (c++) ICE on invalid function template specialization
- * [344]11063 (c++) ICE on parsing initialization list of const array
- member
- * [345]11207 ICE with negative index in array element designator
- * [346]11522 (fortran) g77 dwarf-2 ICE in
- add_abstract_origin_attribute
- * [347]11595 (c++) ICE on duplicate label definition
- * [348]11646 (c++) ICE in commit_one_edge_insertion with
- -fnon-call-exceptions -fgcse -O
- * [349]11665 ICE in struct initializer when taking address
- * [350]11852 (c++) ICE with bad struct initializer.
- * [351]11878 (c++) ICE in cp_expr_size
- * [352]11883 ICE with any -O on mercury-generated C code
- * [353]11991 (c++) ICE in cxx_incomplete_type_diagnostic, in
- cp/typeck2.c when applying typeid operator to template template
- parameter
- * [354]12146 ICE in lookup_template_function, in cp/pt.c
- * [355]12215 ICE in make_label_edge with -fnon-call-exceptions
- -fno-gcse -O2
- * [356]12369 (c++) ICE with templates and friends
- * [357]12446 ICE in emit_move_insn on complicated array reference
- * [358]12510 ICE in final_scan_insn
- * [359]12544 ICE with large parameters used in nested functions
-
- C and optimization bugs
-
- * [360]9862 spurious warnings with -W -finline-functions
- * [361]10962 lookup_field is a linear search on a linked list (can be
- slow if large struct)
- * [362]11370 -Wunreachable-code gives false complaints
- * [363]11637 invalid assembly with -fnon-call-exceptions
- * [364]11885 Problem with bitfields in packed structs
- * [365]12082 Inappropriate unreachable code warnings
- * [366]12180 Inline optimization fails for variadic function
- * [367]12340 loop unroller + gcse produces wrong code
-
- C++ compiler and library
-
- * [368]3907 nested template parameter collides with member name
- * [369]5293 confusing message when binding a temporary to a reference
- * [370]5296 [DR115] Pointers to functions and to template functions
- behave differently in deduction
- * [371]7939 ICE on function template specialization
- * [372]8656 Unable to assign function with __attribute__ and pointer
- return type to an appropriate variable
- * [373]10147 Confusing error message for invalid template function
- argument
- * [374]11400 std::search_n() makes assumptions about Size parameter
- * [375]11409 issues with using declarations, overloading, and
- built-in functions
- * [376]11740 ctype<wchar_t>::do_is(mask, wchar_t) doesn't handle
- multiple bits in mask
- * [377]11786 operator() call on variable in other namespace not
- recognized
- * [378]11867 static_cast ignores ambiguity
- * [379]11928 bug with conversion operators that are typedefs
- * [380]12114 Uninitialized memory accessed in dtor
- * [381]12163 static_cast + explicit constructor regression
- * [382]12181 Wrong code with comma operator and c++
- * [383]12236 regparm and fastcall messes up parameters
- * [384]12266 incorrect instantiation of unneeded template during
- overload resolution
- * [385]12296 istream::peek() doesn't set eofbit
- * [386]12298 [sjlj exceptions] Stack unwind destroys
- not-yet-constructed object
- * [387]12369 ICE with templates and friends
- * [388]12337 apparently infinite loop in g++
- * [389]12344 stdcall attribute ignored if function returns a pointer
- * [390]12451 missing(late) class forward declaration in cxxabi.h
- * [391]12486 g++ accepts invalid use of a qualified name
-
- x86 specific (Intel/AMD)
-
- * [392]8869 [x86 MMX] ICE with const variable optimization and MMX
- builtins
- * [393]9786 ICE in fixup_abnormal_edges with -fnon-call-exceptions
- -O2
- * [394]11689 g++3.3 emits un-assembleable code for k6 architecture
- * [395]12116 [k6] Invalid assembly output values with X-MAME code
- * [396]12070 ICE converting between double and long double with
- -msoft-float
-
- ia64-specific
-
- * [397]11184 [ia64 hpux] ICE on __builtin_apply building libobjc
- * [398]11535 __builtin_return_address may not work on ia64
- * [399]11693 [ia64] ICE in gen_nop_type
- * [400]12224 [ia64] Thread-local storage doesn't work
-
- PowerPC-specific
-
- * [401]11087 [powerpc64-linux] GCC miscompiles raid1.c from linux
- kernel
- * [402]11319 loop miscompiled on ppc32
- * [403]11949 ICE Compiler segfault with ffmpeg -maltivec code
-
- SPARC-specific
-
- * [404]11662 wrong code for expr. with cast to long long and
- exclusive or
- * [405]11965 invalid assembler code for a shift < 32 operation
- * [406]12301 (c++) stack corruption when a returned expression throws
- an exception
-
- Alpha-specific
-
- * [407]11717 [alpha-linux] unrecognizable insn compiling for.c of
- kernel 2.4.22-pre8
-
- HPUX-specific
-
- * [408]11313 problem with #pragma weak and static inline functions
- * [409]11712 __STDC_EXT__ not defined for C++ by default anymore?
-
- Solaris specific
-
- * [410]12166 Profiled programs crash if PROFDIR is set
-
- Solaris-x86 specific
-
- * [411]12101 i386 Solaris no longer works with GNU as?
-
- Miscellaneous embedded target-specific bugs
-
- * [412]10988 [m32r-elf] wrong blockmove code with -O3
- * [413]11805 [h8300-unknown-coff] [H8300] ICE for simple code with
- -O2
- * [414]11902 [sh4] spec file improperly inserts rpath even when none
- needed
- * [415]11903 [sh4] -pthread fails to link due to error in spec file
- on sh4
- __________________________________________________________________
-
-GCC 3.3.3
-
- Minor features
-
- In addition to the bug fixes documented below, this release contains
- few minor features such as:
- * Support for --with-sysroot
- * Support for automatic detection of executable stacks
- * Support for SSE3 instructions
- * Support for thread local storage debugging under GDB on S390
-
- Bug Fixes
-
- This section lists the problem reports (PRs) from GCC's bug tracker
- that are known to be fixed in the 3.3.3 release. This list might not be
- complete (that is, it is possible that some PRs that have been fixed
- are not listed here).
-
- Bootstrap failures and issues
-
- * [416]11890 Building cross gcc-3.3.1 for sparc-sun-solaris2.6 fails
- * [417]12399 boehm-gc fails (when building a cross compiler): libtool
- unable to infer tagged configuration
- * [418]13068 mklibgcc.in doesn't handle multi-level multilib
- subdirectories properly
-
- Internal compiler errors (multi-platform)
-
- * [419]10060 ICE (stack overflow) on huge file (300k lines) due to
- recursive behaviour of copy_rtx_if_shared, in emit_rtl.c
- * [420]10555 (c++) ICE on undefined template argument
- * [421]10706 (c++) ICE in mangle_class_name_for_template
- * [422]11496 (fortran) error in flow_loops_find when -funroll-loops
- active
- * [423]11741 ICE in pre_insert_copy_insn, in gcse.c
- * [424]12440 GCC crashes during compilation of quicktime4linux 2.0.0
- * [425]12632 (fortran) -fbounds-check ICE
- * [426]12712 (c++) ICE on short legit C++ code fragment with gcc
- 3.3.2
- * [427]12726 (c++) ICE (segfault) on trivial code
- * [428]12890 (c++) ICE on compilation of class with throwing method
- * [429]12900 (c++) ICE in rtl_verify_flow_info_1
- * [430]13060 (fortran) ICE in fixup_var_refs_1, in function.c on
- correct code with -O2 -fno-force-mem
- * [431]13289 (c++) ICE in regenerate_decl_from_template on recursive
- template
- * [432]13318 ICE: floating point exception in the loop optimizer
- * [433]13392 (c++) ICE in convert_from_eh_region_ranges_1, in
- except.c
- * [434]13574 (c++) invalid array default initializer in class lets
- gcc consume all memory and die
- * [435]13475 ICE on SIMD variables with partial value initialization
- * [436]13797 (c++) ICE on invalid template parameter
- * [437]13824 (java) gcj SEGV with simple .java program
-
- C and optimization bugs
-
- * [438]8776 loop invariants are not removed (most likely)
- * [439]10339 [sparc,ppc,ppc64] Invalid optimization: replacing
- strncmp by memcmp
- * [440]11350 undefined labels with -Os -fPIC
- * [441]12826 Optimizer removes reference through volatile pointer
- * [442]12500 stabs debug info: void no longer a predefined / builtin
- type
- * [443]12941 builtin-bitops-1.c miscompilation (latent bug)
- * [444]12953 tree inliner bug (in inline_forbidden_p) and fix
- * [445]13041 linux-2.6/sound/core/oss/rate.c miscompiled
- * [446]13507 spurious printf format warning
- * [447]13382 Type information for const pointer disappears during
- optimization.
- * [448]13394 noreturn attribute ignored on recursive invokation
- * [449]13400 Compiled code crashes storing to read-only location
- * [450]13521 Endless loop in calculate_global_regs_live
-
- C++ compiler and library
-
- Some of the bug fixes in this list were made to implement decisions
- that the ISO C++ standards committee has made concerning several defect
- reports (DRs). Links in the list below point to detailed discussion of
- the relevant defect report.
- * [451]2094 unimplemented: use of `ptrmem_cst' in template type
- unification
- * [452]2294 using declaration confusion
- * [453]5050 template instantiation depth exceeds limit: recursion
- problem?
- * [454]9371 Bad exception handling in
- i/ostream::operator>>/<<(streambuf*)
- * [455]9546 bad exception handling in ostream members
- * [456]10081 basic_ios::_M_cache_locale leaves NULL members in the
- face of unknown locales
- * [457]10093 [458][DR 61] Setting failbit in exceptions doesn't work
- * [459]10095 istream::operator>>(int&) sets ios::badbit when
- ios::failbit is set.
- * [460]11554 Warning about reordering of initializers doesn't mention
- location of constructor
- * [461]12297 istream::sentry::sentry() handles eof() incorrectly.
- * [462]12352 Exception safety problems in src/localename.cc
- * [463]12438 Memory leak in locale::combine()
- * [464]12540 Memory leak in locale::locale(const char*)
- * [465]12594 DRs [466]60 [TC] and [467]63 [TC] not implemented
- * [468]12657 Resolution of [469]DR 292 (WP) still unimplemented
- * [470]12696 memory eating infinite loop in diagnostics (error
- recovery problem)
- * [471]12815 Code compiled with optimization behaves unexpectedly
- * [472]12862 Conflicts between typedefs/enums and namespace member
- declarations
- * [473]12926 Wrong value after assignment in initialize list using
- bit-fields
- * [474]12967 Resolution of [475]DR 300 [WP] still unimplemented
- * [476]12971 Resolution of [477]DR 328 [WP] still unimplemented
- * [478]13007 basic_streambuf::pubimbue, imbue wrong
- * [479]13009 Implicitly-defined assignment operator writes to wrong
- memory
- * [480]13057 regparm attribute not applied to destructor
- * [481]13070 -Wformat option ignored in g++
- * [482]13081 forward template declarations in <complex> let inlining
- fail
- * [483]13239 Assertion does not seem to work correctly anymore
- * [484]13262 "xxx is private within this context" when initializing a
- self-contained template class
- * [485]13290 simple typo in concept checking for std::generate_n
- * [486]13323 Template code does not compile in presence of typedef
- * [487]13369 __verify_grouping (and __add_grouping?) not correct
- * [488]13371 infinite loop with packed struct and inlining
- * [489]13445 Template argument replacement "dereferences" a typedef
- * [490]13461 Fails to access protected-ctor from public constant
- * [491]13462 Non-standard-conforming type set::pointer
- * [492]13478 gcc uses wrong constructor to initialize a const
- reference
- * [493]13544 "conflicting types" for enums in different scopes
- * [494]13650 string::compare should not (always) use
- traits_type::length()
- * [495]13683 bogus warning about passing non-PODs through ellipsis
- * [496]13688 Derived class is denied access to protected base class
- member class
- * [497]13774 Member variable cleared in virtual multiple inheritance
- class
- * [498]13884 Protect sstream.tcc from extern template use
-
- Java compiler and library
-
- * [499]10746 [win32] garbage collection crash in GCJ
-
- Objective-C compiler and library
-
- * [500]11433 Crash due to dereferencing null pointer when querying
- protocol
-
- Fortran compiler and library
-
- * [501]12633 logical expression gives incorrect result with
- -fugly-logint option
- * [502]13037 [gcse-lm] g77 generates incorrect code
- * [503]13213 Hex constant problem when compiling with -fugly-logint
- and -ftypeless-boz
-
- x86-specific (Intel/AMD)
-
- * [504]4490 ICE with -m128bit-long-double
- * [505]12292 [x86_64] ICE: RTL check: expected code `const_int', have
- `reg' in make_field_assignment, in combine.c
- * [506]12441 ICE: can't find a register to spill
- * [507]12943 array static-init failure under -fpic, -fPIC
- * [508]13608 Incorrect code with -O3 -ffast-math
-
- PowerPC-specific
-
- * [509]11598 testcase gcc.dg/20020118-1.c fails runtime check of
- __attribute__((aligned(16)))
- * [510]11793 ICE in extract_insn, in recog.c (const_vector's)
- * [511]12467 vmsumubm emitted when vmsummbm appropriate (typo in
- altivec.md)
- * [512]12537 g++ generates writeable text sections
-
- SPARC-specific
-
- * [513]12496 wrong result for __atomic_add(&value, -1) when using -O0
- -m64
- * [514]12865 mprotect call to make trampoline executable may fail
- * [515]13354 ICE in sparc_emit_set_const32
-
- ARM-specific
-
- * [516]10467 [arm] ICE in pre_insert_copy_insn,
-
- ia64-specific
-
- * [517]11226 ICE passing struct arg with two floats
- * [518]11227 ICE for _Complex float, _Complex long double args
- * [519]12644 GCC 3.3.2 fails to compile glibc on ia64
- * [520]13149 build gcc-3.3.2 1305 error:unrecognizable insn
- * Various fixes for libunwind
-
- Alpha-specific
-
- * [521]12654 Incorrect comparison code generated for Alpha
- * [522]12965 SEGV+ICE in cc1plus on alpha-linux with -O2
- * [523]13031 ICE (unrecognizable insn) when building gnome-libs-1.4.2
-
- HPPA-specific
-
- * [524]11634 [hppa] ICE in verify_local_live_at_start, in flow.c
- * [525]12158 [hppa] compilation does not terminate at -O1
-
- S390-specific
-
- * [526]11992 Wrong built-in code for memcmp with length 1<<24: only
- (1<<24)-1 possible for CLCL-Instruction
-
- SH-specific
-
- * [527]9365 segfault in gen_far_branch (config/sh/sh.c)
- * [528]10392 optimizer generates faulty array indexing
- * [529]11322 SH profiler outputs multiple definitions of symbol
- * [530]13069 gcc/config/sh/rtems.h broken
- * [531]13302 Putting a va_list in a struct causes seg fault
- * [532]13585 Incorrect optimization of call to sfunc
- * Fix inappropriately exported libgcc functions from the shared
- library
-
- Other embedded target specific
-
- * [533]8916 [mcore] unsigned char assign gets hosed.
- * [534]11576 [h8300] ICE in change_address_1, in emit-rtl.c
- * [535]13122 [h8300] local variable gets corrupted by function call
- when -fomit-frame-pointer is given
- * [536]13256 [cris] strict_low_part mistreated in delay slots
- * [537]13373 [mcore] optimization with -frerun-cse-after-loop
- -fexpensive-optimizations produces wrong code on mcore
-
- GNU HURD-specific
-
- * [538]12561 gcc/config/t-gnu needs updating to work with
- --with-sysroot
-
- Tru64 Unix specific
-
- * [539]6243 testsuite fails almost all tests due to no libintl in
- LD_LIBRARY_PATH during test.
- * [540]11397 weak aliases broken on Tru64 UNIX
-
- AIX-specific
-
- * [541]12505 build failure due to defines of uchar in cpphash.h and
- sys/types.h
- * [542]13150 WEAK symbols not exported by collect2
-
- IRIX-specific
-
- * [543]12666 fixincludes problem on IRIX 6.5.19m
-
- Solaris-specific
-
- * [544]12969 Including sys/byteorder.h breaks configure checks
-
- Testsuite problems (compiler is not affected)
-
- * [545]10819 testsuite creates CR+LF on compiler version lines in
- test summary files
- * [546]11612 abi_check not finding correct libgcc_s.so.1
-
- Miscellaneous
-
- * [547]13211 using -###, incorrect warnings about unused linker file
- are produced
- __________________________________________________________________
-
-GCC 3.3.4
-
- This is the [548]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.3.4 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
- __________________________________________________________________
-
-GCC 3.3.5
-
- This is the [549]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.3.5 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
- __________________________________________________________________
-
-GCC 3.3.6
-
- This is the [550]list of problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.3.6 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here).
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [551]GCC manuals. If that fails, the
- [552]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [553]gcc at gcc.gnu.org. All of [554]our lists have public
- archives.
-
- Copyright (C) [555]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [556]maintained by the GCC team. Last modified
- 2014-06-28[557].
-
-References
-
- 1. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.6
- 2. http://gcc.gnu.org/gcc-3.1/changes.html#obsolete_systems
- 3. http://gcc.gnu.org/gcc-3.3/changes.html#obsolete_systems
- 4. http://gcc.gnu.org/gcc-3.3/changes.html#nonnull_attribute
- 5. http://gcc.gnu.org/news/dfa.html
- 6. http://gcc.gnu.org/c99status.html
- 7. https://gcc.gnu.org/onlinedocs/gcc-3.3.6/g77/News.html
- 8. https://gcc.gnu.org/PR10140
- 9. https://gcc.gnu.org/PR10198
- 10. https://gcc.gnu.org/PR10338
- 11. https://gcc.gnu.org/PR3581
- 12. https://gcc.gnu.org/PR4382
- 13. https://gcc.gnu.org/PR5533
- 14. https://gcc.gnu.org/PR6387
- 15. https://gcc.gnu.org/PR6412
- 16. https://gcc.gnu.org/PR6620
- 17. https://gcc.gnu.org/PR6663
- 18. https://gcc.gnu.org/PR7068
- 19. https://gcc.gnu.org/PR7083
- 20. https://gcc.gnu.org/PR7647
- 21. https://gcc.gnu.org/PR7675
- 22. https://gcc.gnu.org/PR7718
- 23. https://gcc.gnu.org/PR8116
- 24. https://gcc.gnu.org/PR8358
- 25. https://gcc.gnu.org/PR8511
- 26. https://gcc.gnu.org/PR8564
- 27. https://gcc.gnu.org/PR8660
- 28. https://gcc.gnu.org/PR8766
- 29. https://gcc.gnu.org/PR8803
- 30. https://gcc.gnu.org/PR8846
- 31. https://gcc.gnu.org/PR8906
- 32. https://gcc.gnu.org/PR9216
- 33. https://gcc.gnu.org/PR9261
- 34. https://gcc.gnu.org/PR9263
- 35. https://gcc.gnu.org/PR9429
- 36. https://gcc.gnu.org/PR9516
- 37. https://gcc.gnu.org/PR9600
- 38. https://gcc.gnu.org/PR9629
- 39. https://gcc.gnu.org/PR9672
- 40. https://gcc.gnu.org/PR9749
- 41. https://gcc.gnu.org/PR9794
- 42. https://gcc.gnu.org/PR9829
- 43. https://gcc.gnu.org/PR9916
- 44. https://gcc.gnu.org/PR9936
- 45. https://gcc.gnu.org/PR10262
- 46. https://gcc.gnu.org/PR10278
- 47. https://gcc.gnu.org/PR10446
- 48. https://gcc.gnu.org/PR10451
- 49. https://gcc.gnu.org/PR10506
- 50. https://gcc.gnu.org/PR10549
- 51. https://gcc.gnu.org/PR2001
- 52. https://gcc.gnu.org/PR2391
- 53. https://gcc.gnu.org/PR2960
- 54. https://gcc.gnu.org/PR4046
- 55. https://gcc.gnu.org/PR6405
- 56. https://gcc.gnu.org/PR6798
- 57. https://gcc.gnu.org/PR6871
- 58. https://gcc.gnu.org/PR6909
- 59. https://gcc.gnu.org/PR7189
- 60. https://gcc.gnu.org/PR7642
- 61. https://gcc.gnu.org/PR8634
- 62. https://gcc.gnu.org/PR8750
- 63. https://gcc.gnu.org/PR2161
- 64. https://gcc.gnu.org/PR4319
- 65. https://gcc.gnu.org/PR8602
- 66. https://gcc.gnu.org/PR9177
- 67. https://gcc.gnu.org/PR9853
- 68. https://gcc.gnu.org/PR45
- 69. https://gcc.gnu.org/PR3784
- 70. https://gcc.gnu.org/PR764
- 71. https://gcc.gnu.org/PR5116
- 72. https://gcc.gnu.org/PR2862
- 73. https://gcc.gnu.org/PR3663
- 74. https://gcc.gnu.org/PR3797
- 75. https://gcc.gnu.org/PR3948
- 76. https://gcc.gnu.org/PR4137
- 77. https://gcc.gnu.org/PR4361
- 78. https://gcc.gnu.org/PR4802
- 79. https://gcc.gnu.org/PR5837
- 80. https://gcc.gnu.org/PR4803
- 81. https://gcc.gnu.org/PR5094
- 82. https://gcc.gnu.org/PR5730
- 83. https://gcc.gnu.org/PR6713
- 84. https://gcc.gnu.org/PR7015
- 85. https://gcc.gnu.org/PR7086
- 86. https://gcc.gnu.org/PR7099
- 87. https://gcc.gnu.org/PR7247
- 88. https://gcc.gnu.org/PR7441
- 89. https://gcc.gnu.org/PR7768
- 90. https://gcc.gnu.org/PR7804
- 91. https://gcc.gnu.org/PR8099
- 92. https://gcc.gnu.org/PR8117
- 93. https://gcc.gnu.org/PR8205
- 94. https://gcc.gnu.org/PR8645
- 95. https://gcc.gnu.org/PR8724
- 96. https://gcc.gnu.org/PR8805
- 97. https://gcc.gnu.org/PR8691
- 98. https://gcc.gnu.org/PR8700
- 99. https://gcc.gnu.org/PR8724
- 100. https://gcc.gnu.org/PR8949
- 101. https://gcc.gnu.org/PR9016
- 102. https://gcc.gnu.org/PR9053
- 103. https://gcc.gnu.org/PR9152
- 104. https://gcc.gnu.org/PR9182
- 105. https://gcc.gnu.org/PR9297
- 106. https://gcc.gnu.org/PR9318
- 107. https://gcc.gnu.org/PR9320
- 108. https://gcc.gnu.org/PR9400
- 109. https://gcc.gnu.org/PR9424
- 110. https://gcc.gnu.org/PR9425
- 111. https://gcc.gnu.org/PR9439
- 112. https://gcc.gnu.org/PR9474
- 113. https://gcc.gnu.org/PR9548
- 114. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#231
- 115. https://gcc.gnu.org/PR9555
- 116. https://gcc.gnu.org/PR9561
- 117. https://gcc.gnu.org/PR9563
- 118. https://gcc.gnu.org/PR9582
- 119. https://gcc.gnu.org/PR9622
- 120. https://gcc.gnu.org/PR9683
- 121. https://gcc.gnu.org/PR9791
- 122. https://gcc.gnu.org/PR9817
- 123. https://gcc.gnu.org/PR9825
- 124. https://gcc.gnu.org/PR9826
- 125. https://gcc.gnu.org/PR9924
- 126. https://gcc.gnu.org/PR9946
- 127. https://gcc.gnu.org/PR9964
- 128. https://gcc.gnu.org/PR9988
- 129. https://gcc.gnu.org/PR10033
- 130. https://gcc.gnu.org/PR10097
- 131. https://gcc.gnu.org/PR10132
- 132. https://gcc.gnu.org/PR10180
- 133. https://gcc.gnu.org/PR10199
- 134. https://gcc.gnu.org/PR10300
- 135. https://gcc.gnu.org/PR10427
- 136. https://gcc.gnu.org/PR10503
- 137. https://gcc.gnu.org/PR5956
- 138. https://gcc.gnu.org/PR1832
- 139. https://gcc.gnu.org/PR3924
- 140. https://gcc.gnu.org/PR5634
- 141. https://gcc.gnu.org/PR6367
- 142. https://gcc.gnu.org/PR6491
- 143. https://gcc.gnu.org/PR6742
- 144. https://gcc.gnu.org/PR7113
- 145. https://gcc.gnu.org/PR7236
- 146. https://gcc.gnu.org/PR7278
- 147. https://gcc.gnu.org/PR7384
- 148. https://gcc.gnu.org/PR7388
- 149. https://gcc.gnu.org/PR8587
- 150. https://gcc.gnu.org/PR9038
- 151. https://gcc.gnu.org/PR10197
- 152. https://gcc.gnu.org/PR6005
- 153. https://gcc.gnu.org/PR6389
- 154. https://gcc.gnu.org/PR6576
- 155. https://gcc.gnu.org/PR6652
- 156. https://gcc.gnu.org/PR7060
- 157. https://gcc.gnu.org/PR7073
- 158. https://gcc.gnu.org/PR7180
- 159. https://gcc.gnu.org/PR7416
- 160. https://gcc.gnu.org/PR7570
- 161. https://gcc.gnu.org/PR7578
- 162. https://gcc.gnu.org/PR7611
- 163. https://gcc.gnu.org/PR7709
- 164. https://gcc.gnu.org/PR7766
- 165. https://gcc.gnu.org/PR7785
- 166. https://gcc.gnu.org/PR7786
- 167. https://gcc.gnu.org/PR8142
- 168. https://gcc.gnu.org/PR8234
- 169. https://gcc.gnu.org/PR8415
- 170. https://gcc.gnu.org/PR8481
- 171. https://gcc.gnu.org/PR8593
- 172. https://gcc.gnu.org/PR8759
- 173. https://gcc.gnu.org/PR8997
- 174. https://gcc.gnu.org/PR9253
- 175. https://gcc.gnu.org/PR9254
- 176. https://gcc.gnu.org/PR9271
- 177. https://gcc.gnu.org/PR6767
- 178. https://gcc.gnu.org/PR9911
- 179. https://gcc.gnu.org/PR10020
- 180. https://gcc.gnu.org/PR10546
- 181. https://gcc.gnu.org/PR7029
- 182. https://gcc.gnu.org/PR2903
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-======================================================================
-http://gcc.gnu.org/gcc-3.2/index.html
- GCC 3.2 Release Series
-
- April 25, 2003
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 3.2.3.
-
- The purpose of the GCC 3.2 release series is to provide a stable
- platform for OS distributors to use building their next releases. A
- primary objective was to stabilize the C++ ABI; we believe that the
- interface to the compiler and the C++ standard library are now
- relatively stable.
-
- Be aware that C++ code compiled by GCC 3.2.x will (in general) not
- interoperate with code compiled by GCC 3.1.1 or earlier.
-
- Please refer to our [2]detailed list of news, caveats, and bug-fixes
- for further information.
-
-Release History
-
- GCC 3.2.3
- April 25, 2003 ([3]changes)
-
- GCC 3.2.2
- February 5, 2003 ([4]changes)
-
- GCC 3.2.1
- November 19, 2002 ([5]changes)
-
- GCC 3.2
- August 14, 2002 ([6]changes)
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [7]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, improvements, bug fixes, and other changes as
- well as test results to GCC. This [8]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [9]GCC project
- web site or contact the [10]GCC development mailing list.
-
- To obtain GCC please use [11]our mirror sites, or our CVS server.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [12]GCC manuals. If that fails, the
- [13]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [14]gcc at gcc.gnu.org. All of [15]our lists have public
- archives.
-
- Copyright (C) [16]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [17]maintained by the GCC team. Last modified
- 2014-06-28[18].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-3.2/changes.html
- 3. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.3
- 4. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.2
- 5. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.1
- 6. http://gcc.gnu.org/gcc-3.2/changes.html#3.2
- 7. http://gcc.gnu.org/gcc-3.2/buildstat.html
- 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 9. http://gcc.gnu.org/index.html
- 10. mailto:gcc at gcc.gnu.org
- 11. http://gcc.gnu.org/mirrors.html
- 12. https://gcc.gnu.org/onlinedocs/
- 13. mailto:gcc-help at gcc.gnu.org
- 14. mailto:gcc at gcc.gnu.org
- 15. https://gcc.gnu.org/lists.html
- 16. http://www.fsf.org/
- 17. https://gcc.gnu.org/about.html
- 18. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.2/changes.html
- GCC 3.2 Release Series
- Changes, New Features, and Fixes
-
- The latest release in the 3.2 release series is [1]GCC 3.2.3.
-
-Caveats and New Features
-
- Caveats
-
- * The C++ compiler does not correctly zero-initialize
- pointers-to-data members. You must explicitly initialize them. For
- example: int S::*m(0); will work, but depending on
- default-initialization to zero will not work. This bug cannot be
- fixed in GCC 3.2 without inducing unacceptable risks. It will be
- fixed in GCC 3.3.
- * This GCC release is based on the GCC 3.1 sourcebase, and thus has
- all the [2]changes in the GCC 3.1 series. In addition, GCC 3.2 has
- a number of C++ ABI fixes which make its C++ compiler generate
- binary code which is incompatible with the C++ compilers found in
- earlier GCC releases, including GCC 3.1 and GCC 3.1.1.
-
- Frontend Enhancements
-
- C/C++/Objective-C
-
- * The method of constructing the list of directories to be searched
- for header files has been revised. If a directory named by a -I
- option is a standard system include directory, the option is
- ignored to ensure that the default search order for system
- directories and the special treatment of system header files are
- not defeated.
- * The C and Objective-C compilers no longer accept the "Naming Types"
- extension (typedef foo = bar); it was already unavailable in C++.
- Code which uses it will need to be changed to use the "typeof"
- extension instead: typedef typeof(bar) foo. (We have removed this
- extension without a period of deprecation because it has caused the
- compiler to crash since version 3.0 and no one noticed until very
- recently. Thus we conclude it is not in widespread use.)
-
- C++
-
- * GCC 3.2 fixed serveral differences between the C++ ABI implemented
- in GCC and the multi-vendor standard, but more have been found
- since the release. 3.2.1 adds a new warning, -Wabi, to warn about
- code which is affected by these bugs. We will fix these bugs in
- some future release, once we are confident that all have been
- found; until then, it is our intention to make changes to the ABI
- only if they are necessary for correct compilation of C++, as
- opposed to conformance to the ABI documents.
- * For details on how to build an ABI compliant compiler for GNU/Linux
- systems, check the [3]common C++ ABI page.
-
- New Targets and Target Specific Improvements
-
- IA-32
-
- * Fixed a number of bugs in SSE and MMX intrinsics.
- * Fixed common compiler crashes with SSE instruction set enabled
- (implied by -march=pentium3, pentium4, athlon-xp)
- * __m128 and __m128i is not 128bit aligned when used in structures.
-
- x86-64
-
- * A bug whereby the compiler could generate bad code for bzero has
- been fixed.
- * ABI fixes (implying ABI incompatibilities with previous version in
- some corner cases)
- * Fixed prefetch code generation
- __________________________________________________________________
-
-GCC 3.2.3
-
- 3.2.3 is a bug fix release only; there are no new features that were
- not present in GCC 3.2.2.
-
- Bug Fixes
-
- This section lists the problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.2.3 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here), and some of the titles have been changed to
- make them more clear.
-
- Internal Compiler Errors (multi-platform)
-
- * [4]3782: (c++) -quiet -fstats produces a segmentation fault in
- cc1plus
- * [5]6440: (c++) template specializations cause ICE
- * [6]7050: (c++) ICE on: (i ? get_string() : throw)
- * [7]7741: ICE on conflicting types (make_decl_rtl in varasm.c)
- * [8]7982: (c++) ICE due to infinite recursion (using STL set)
- * [9]8068: exceedingly high (infinite) memory usage
- * [10]8178: ICE with __builtin_ffs
- * [11]8396: ICE in copy_to_mode_reg, in explow.c
- * [12]8674: (c++) ICE in cp_expr_size, in cp/cp-lang.c
- * [13]9768: ICE when optimizing inline code at -O2
- * [14]9798: (c++) Infinite recursion (segfault) in
- cp/decl.c:push_using_directive with recursive using directives
- * [15]9799: mismatching structure initializer with nested flexible
- array member: ICE
- * [16]9928: ICE on duplicate enum declaration
- * [17]10114: ICE in mem_loc_descriptor, in dwarf2out.c (affects
- sparc, alpha)
- * [18]10352: ICE in find_reloads_toplev
- * [19]10336: ICE with -Wunreachable-code
-
- C/optimizer bugs:
-
- * [20]8224: Incorrect joining of signed and unsigned division
- * [21]8613: -O2 produces wrong code with builtin strlen and
- postincrements
- * [22]8828: gcc reports some code is unreachable when it is not
- * [23]9226: GCSE breaking argument passing
- * [24]9853: miscompilation of non-constant structure initializer
- * [25]9797: C99-style struct initializers are miscompiled
- * [26]9967: Some standard C function calls should not be replaced
- when optimizing for size
- * [27]10116: ce2: invalid merge of join_bb in the context of switch
- statements
- * [28]10171: wrong code for inlined function
- * [29]10175: -Wunreachable-code doesn't work for single lines
-
- C++ compiler and library:
-
- * [30]8316: Confusing diagnostic for code that misuses conversion
- operators
- * [31]9169: filebuf output fails if codecvt<>::out returns noconv
- * [32]9420: incomplete type incorrectly reported
- * [33]9459: typeof in return type specification of template not
- supported
- * [34]9507: filebuf::open handles ios_base::ate incorrectly
- * [35]9538: Out-of-bounds memory access in streambuf::sputbackc
- * [36]9602: Total confusion about template/friend/virtual/abstract
- * [37]9993: destructor not called for local object created within and
- returned from infinite loop
- * [38]10167: ieee_1003.1-2001 locale specialisations on a glibc-2.3.2
- system
-
- Java compiler and library:
-
- * [39]9652: libgcj build fails on irix6.5.1[78]
- * [40]10144: gas on solaris complains about bad .stabs lines for
- java, native as unaffected
-
- x86-specific (Intel/AMD):
-
- * [41]8746: gcc miscompiles Linux kernel ppa driver on x86
- * [42]9888: -mcpu=k6 -Os produces out of range loop instructions
- * [43]9638: Cross-build for target i386-elf and i586-pc-linux-gnu
- failed
- * [44]9954: Cross-build for target i586-pc-linux-gnu (--with-newlib)
- failed
-
- SPARC-specific:
-
- * [45]7784: [Sparc] ICE in extract_insn, in recog.c
- * [46]7796: sparc extra failure with -m64 on execute/930921-1.c in
- unroll.c
- * [47]8281: ICE when compiling with -O2 -fPIC for Ultrasparc
- * [48]8366: [Sparc] C testsuite failure with -m64 -fpic -O in
- execute/loop-2d.c
- * [49]8726: gcc -O2 miscompiles Samba 2.2.7 on 32-bit sparc
- * [50]9414: Scheduling bug on Ultrasparc
- * [51]10067: GCC-3.2.2 outputs invalid asm on sparc64
-
- m68k-specific:
-
- * [52]7248: broken "inclusive or" code
- * [53]8343: m68k-elf/rtems ICE at instantiate_virtual_regs_1
-
- PowerPC-specific:
-
- * [54]9732: Wrong code with -O2 -fPIC
- * [55]10073: ICE: powerpc cannot split insn
-
- Alpha-specific:
-
- * [56]7702: optimization problem on a DEC alpha under OSF1
- * [57]9671: gcc.3.2.2 does not build on a HP Tru64 Unix v5.1B system
-
- HP-specific:
-
- * [58]8694: <string> breaks <ctype.h> on HP-UX 10.20 (DUP: 9275)
- * [59]9953: (ada) gcc 3.2.x can't build 3.3-branch ada on HP-UX 10
- (missing symbol)
- * [60]10271: Floating point args don't get reloaded across function
- calls with -O2
-
- MIPS specific:
-
- * [61]6362: mips-irix6 gcc-3.1 C testsuite failure with -mips4 in
- compile/920501-4.c
-
- CRIS specific:
-
- * [62]10377: gcc-3.2.2 creates bad assembler code for cris
-
- Miscellaneous and minor bugs:
-
- * [63]6955: collect2 says "core dumped" when there is no core
- __________________________________________________________________
-
-GCC 3.2.2
-
- Beginning with 3.2.2, GCC's Makefile suite supports redirection of make
- install by means of the DESTDIR variable. Parts of the GCC tree have
- featured that support long before, but now it is available even from
- the top level.
-
- Other than that, GCC 3.2.2 is a bug fix release only; there are no new
- features that were not present in GCC 3.2.1.
-
- Bug Fixes
-
- On the following i386-based systems GCC 3.2.1 broke the C ABI wrt.
- functions returning structures: Cygwin, FreeBSD (GCC 3.2.1 as shipped
- with FreeBSD 5.0 does not have this problem), Interix, a.out-based
- GNU/Linux and NetBSD, OpenBSD, and Darwin. GCC 3.2.2 reverts this ABI
- change, and thus restores ABI-compatibility with previous releases
- (except GCC 3.2.1) on these platforms.
-
- This section lists the problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.2.2 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here) and some of the titles have been changed to
- make them more clear.
-
- Internal Compiler Errors (multi-platform)
-
- * [64]5919: (c++) ICE when passing variable array to template
- function
- * [65]7129: (c++) ICE with min/max assignment operators (<?= and >?=)
- * [66]7507: ICE with -O2 when address of called function is a
- complicated expression
- * [67]7622: ICE with nested inline functions if function's address is
- taken
- * [68]7681: (fortran) ICE in compensate_edge, in reg-stack.c (also PR
- [69]9258)
- * [70]8031: (c++) ICE in code comparing typeids and casting from
- virtual base
- * [71]8275: ICE in simplify_subreg
- * [72]8332: (c++) builtin strlen/template interaction causes ICE
- * [73]8372: (c++) ICE on explicit call of destructor
- * [74]8439: (c, not c++) empty struct causes ICE
- * [75]8442: (c++) ICE with nested template classes
- * [76]8518: ICE when compiling mplayer ("extern inline" issue)
- * [77]8615: (c++) ICE with out-of-range character constant template
- argument
- * [78]8663: (c++) ICE in cp_expr_size, at cp-lang.c:307
- * [79]8799: (c++) ICE: error reporting routines re-entered
- * [80]9328: (c++) ICE with typeof(X) for overloaded X
- * [81]9465: (preprocessor) cpp -traditional ICE on null bytes
-
- C++ (compiler and library) bugs
-
- * [82]47: scoping in nested classes is broken
- * [83]6745: problems with iostream rdbuf() member function
- * [84]8214: conversion from const char* const to char* sometimes
- accepted illegally
- * [85]8493: builtin strlen and overload resolution (same bug as
- [86]8332)
- * [87]8503: strange behaviour of function types
- * [88]8727: compiler confused by inheritance from an anonymous struct
- * [89]7445: poor performance of std::locale::classic() in
- multi-threaded applications
- * [90]8230: mishandling of overflow in vector<T>::resize
- * [91]8399: sync_with_stdio(false) breaks unformatted input
- * [92]8662: illegal access of private member of unnamed class is
- accepted
- * [93]8707: "make distclean" fails in libstdc++-v3 directory
- * [94]8708: __USE_MALLOC doesn't work
- * [95]8790: Use of non-thread-safe strtok in src/localename.cc
- * [96]8887: Bug in date formats with --enable-clocale=generic
- * [97]9076: Call Frame Instructions are not handled correctly during
- unwind operation
- * [98]9151: std::setprecision limited to 16 digits when outputting a
- double to a stream
- * [99]9168: codecvt<char, char, mbstate_t> overwrites output buffers
- * [100]9269: libstdc++ headers: explicit specialization of function
- must precede its first use
- * [101]9322: return value of basic_streambuf<>::getloc affected by
- locale::global
- * [102]9433: segfault in runtime support for dynamic_cast
-
- C and optimizer bugs
-
- * [103]8032: GCC incorrectly initializes static structs that have
- flexible arrays
- * [104]8639: simple arithmetic expression broken
- * [105]8794: optimization improperly eliminates certain expressions
- * [106]8832: traditional "asm volatile" code is illegally optimized
- * [107]8988: loop optimizer bug: with -O2, code is generated that
- segfaults (found on i386, bug present for all platforms)
- * [108]9492: structure copy clobbers subsequent stores to structure
-
- Objective-C bugs
-
- * [109]9267: Objective-C parser won't build with newer bison versions
- (e.g. 1.875)
-
- Ada bugs
-
- * [110]8344: Ada build problem due to conflict between gcc/final.o,
- gcc/ada/final.o
-
- Preprocessor bugs
-
- * [111]8524: _Pragma within macros is improperly expanded
- * [112]8880: __WCHAR_TYPE__ macro incorrectly set to "long int" with
- -fshort-wchar
-
- ARM-specific
-
- * [113]9090: arm ICE with >= -O2; regression from gcc-2.95
-
- x86-specific (Intel/AMD)
-
- * [114]8588: ICE in extract_insn, at recog.c:NNNN (shift instruction)
- * [115]8599: loop unroll bug with -march=k6-3
- * [116]9506: ABI breakage in structure return (affects BSD and
- Cygwin, but not GNU/Linux)
-
- FreeBSD 5.0 specific
-
- * [117]9484: GCC 3.2.1 Bootstrap failure on FreeBSD 5.0
-
- RTEMS-specific
-
- * [118]9292: hppa1.1-rtems configurery problems
- * [119]9293: [m68k-elf/rtems] config/m68k/t-crtstuff bug
- * [120]9295: [mips-rtems] config/mips/rtems.h init/fini issue
- * [121]9296: gthr-rtems regression
- * [122]9316: powerpc-rtems: extending multilibs
-
- HP-PA specific
-
- * [123]9493: ICE with -O2 when building a simple function
-
- Documentation
-
- * [124]7341: hyperlink to gcov in GCC documentation doesn't work
- * [125]8947: Please add a warning about "-malign-double" in docs
- * [126]7448, [127]8882: typo cleanups
- __________________________________________________________________
-
-GCC 3.2.1
-
- 3.2.1 adds a new warning, -Wabi. This option warns when GNU C++
- generates code that is known not to be binary-compatible with the
- vendor-neutral ia32/ia64 ABI. Please consult the GCC manual, included
- in the distribution, for details.
-
- This release also removes an old GCC extension, "naming types", and the
- documentation now directs users to use a different GCC extension,
- __typeof__, instead. The feature had evidently been broken for a while.
-
- Otherwise, 3.2.1 is a bug fix release only; other than bug fixes and
- the new warning there are no new features that were not present in GCC
- 3.2.
-
- In addition, the previous fix for [128]PR 7445 (poor performance of
- std::locale::classic() in multi-threaded applications) was reverted
- ("unfixed"), because the "fix" was not thread-safe.
-
- Bug Fixes
-
- This section lists the problem reports (PRs) from GCC's bug tracking
- system that are known to be fixed in the 3.2.1 release. This list might
- not be complete (that is, it is possible that some PRs that have been
- fixed are not listed here). As you can see, the number of bug fixes is
- quite large, so it is strongly recommended that users of earlier GCC
- 3.x releases upgrade to GCC 3.2.1.
-
- Internal Compiler Errors (multi-platform)
-
- * [129]2521: (c++) ICE in build_ptrmemfunc, in cp/typeck.c
- * [130]5661: (c++) ICE instantiating template on array of unknown
- size (bad code)
- * [131]6419: (c++) ICE in make_decl_rtl for "longest" attribute on
- 64-bit platforms
- * [132]6994: (c++) ICE in find_function_data
- * [133]7150: preprocessor: GCC -dM -E gives an ICE
- * [134]7160: ICE when optimizing branches without a return value
- * [135]7228: (c++) ICE when using member template and template
- function
- * [136]7266: (c++) ICE with -pedantic on missing typename
- * [137]7353: ICE from use of "Naming Types" extension, see above
- * [138]7411: ICE in instantiate_virtual_regs_1, in function.c
- * [139]7478: (c++) ICE on static_cast inside template
- * [140]7526: preprocessor core dump when _Pragma implies #pragma
- dependency
- * [141]7721: (c++) ICE on simple (but incorrect) template ([142]7803
- is a duplicate)
- * [143]7754: (c++) ICE on union with template parameter
- * [144]7788: (c++) redeclaring a definition as an incomplete class
- causes ICE
- * [145]8031: (c++) ICE in comptypes, in cp/typeck.c
- * [146]8055: preprocessor dies with SIG11 when building FreeBSD
- kernel
- * [147]8067: (c++) ICE due to mishandling of __FUNCTION__ and related
- variables
- * [148]8134: (c++) ICE in force_store_init_value on legal code
- * [149]8149: (c++) ICE on incomplete type
- * [150]8160: (c++) ICE in build_modify_expr, in cp/typeck.c: array
- initialization
-
- C++ (compiler and library) bugs
-
- * [151]5607: No pointer adjustment in covariant return types
- * [152]6579: Infinite loop with statement expressions in member
- initialization
- * [153]6803: Default copy constructor bug in GCC 3.1
- * [154]7176: g++ confused by friend and static member with same name
- * [155]7188: Segfault with template class and recursive (incorrect)
- initializer list
- * [156]7306: Regression: GCC 3.x fails to compile code with virtual
- inheritance if a method has a variable number of arguments
- * [157]7461: ctype<char>::classic_table() returns offset array on
- Cygwin
- * [158]7524: f(const float arg[3]) fails
- * [159]7584: Erroneous ambiguous base error on using declaration
- * [160]7676: Member template overloading problem
- * [161]7679: infinite loop when a right parenthesis is missing
- * [162]7811: default locale not taken from environment
- * [163]7961: compare( char *) implemented incorrectly in
- basic_string<>
- * [164]8071: basic_ostream::operator<<(streambuf*) loops forever if
- streambuf::underflow() leaves gptr() NULL (dups: [165]8127,
- [166]6745)
- * [167]8096: deque::at() throws std::range_error instead of
- std::out_of_range
- * [168]8127: cout << cin.rdbuf() infinite loop
- * [169]8218: Excessively large memory consumed for classes with large
- array members
- * [170]8287: GCC 3.2: Destructor called for non-constructed local
- object
- * [171]8347: empty vector range used in string construction causes
- core dump
- * [172]8348: fail() flag is set in istringstream when eof() flag is
- set
- * [173]8391: regression: infinite loop in cp/decl2.c(finish_file)
-
- C and optimizer bugs
-
- * [174]6627: -fno-align-functions doesn't seem to disable function
- alignment
- * [175]6631: life_analysis misoptimizes code to initialize fields of
- a structure
- * [176]7102: unsigned char division results in floating exception
- * [177]7120: Run once loop should *always* be unrolled
- (pessimization)
- * [178]7209: Bug involving array referencing and ?: operator
- * [179]7515: invalid inlining of global function with -O3
- * [180]7814: incorrect scheduling for glibc-2.2.92 strcpy test
- * [181]8467: bug in sibling call optimization
-
- Preprocessor bugs
-
- * [182]4890: incorrect line markers from the traditional preprocessor
- * [183]7357: -M option omits system headers files (making it the same
- as -MM)
- * [184]7358: Changes to Sun's make Dependencies
- * [185]7602: C++ header files found in CPLUS_INCLUDE_PATH treated as
- C headers
- * [186]7862: Interrupting GCC -MD removes .d file but not .o
- * [187]8190: Failed compilation deletes -MD dependency file
- * [188]8524: _Pragma within macro is improperly expanded
-
- x86 specific (Intel/AMD)
-
- * [189]5351: (i686-only) function pass-by-value structure copy
- corrupts stack ([190]7591 is a duplicate)
- * [191]6845, [192]7034, [193]7124, [194]7174: ICE's with
- -march=pentium3/pentium2/athlon (these are all the same underlying
- bug, in MMX register use)
- * [195]7134, [196]7375, [197]7390: ICE with -march=athlon (maybe same
- as above?)
- * [198]6890: xmmintrin.h, _MM_TRANSPOSE4_PS is broken
- * [199]6981: wrong code in 64-bit manipulation on x86
- * [200]7242: GCC -mcpu=pentium[23] doesn't define __tune_pentiumpro__
- macro
- * [201]7396: ix86: cmpgt_ss, cmpge_ss, cmpngt_ss, and cmpnge_ss SSE
- intrinsics are broken
- * [202]7630: GCC 3.2 breaks on Mozilla 1.0's JS sources with
- -march=pentium4
- * [203]7693: Typo in i386 mmintrin.h header
- * [204]7723: ICE - Pentium3 sse - GCC 3.2
- * [205]7951: ICE on -march=pentium4 -O2 -mfpmath=sse
- * [206]8146: (i686 only) gcc 3.2 miscompiles gcc 2.95.3
-
- PowerPC specific
-
- * [207]5967: GCC bug when profiling nested functions on powerpc
- * [208]6984: wrong code generated with -O2, -O3, -Os for do-while
- loop on PowerPC
- * [209]7114: PowerPC: ICE building strcoll.op from glibc-2.2.5
- * [210]7130: miscompiled code for GCC-3.1 on
- powerpc-unknown-linux-gnu with -funroll-all-loops
- * [211]7133: PowerPC ICE: unrecognizable insn
- * [212]7380: ICE in extract_insn, at recog.c:2148
- * [213]8252: ICE on Altivec code with optimization turned on
- * [214]8451: Altivec ICE in GCC 3.2
-
- HP/PA specific
-
- * [215]7250: __ashrdi3 returns wrong value on 32 bit hppa
-
- SPARC specific
-
- * [216]6668: when using --disable-multilib, libgcc_s.so is installed
- in the wrong place on sparc-solaris
- * [217]7151: ICE when compiling for UltraSPARC
- * [218]7335: SPARC: ICE in verify_wide_reg (flow.c:557) with long
- double and -O1
- * [219]7842: [REGRESSION] SPARC code gen bug
-
- ARM specific
-
- * [220]7856: [arm] invalid offset in constant pool reference
- * [221]7967: optimization produces wrong code (ARM)
-
- Alpha specific
-
- * [222]7374: __builtin_fabsl broken on alpha
-
- IBM s390 specific
-
- * [223]7370: ICE in fixup_var_refs_1 on s390x
- * [224]7409: loop optimization bug on s390x-linux-gnu
- * [225]8232: s390x: ICE when using bcmp with int length argument
-
- SCO specific
-
- * [226]7623: SCO OpenServer build fails with machmode.def: undefined
- symbol: BITS_PER_UNIT
-
- m68k/Coldfire specific
-
- * [227]8314: crtbegin, crtend need to be multilib'ed for this
- platform
-
- Documentation
-
- * [228]761: Document some undocumented options
- * [229]5610: Fix documentation about invoking SSE instructions
- (-mfpmath=sse)
- * [230]7484: List -Wmissing-declarations as C-only option
- * [231]7531: -mcmodel not documented for x86-64
- * [232]8120: Update documentation of bad use of ##
- __________________________________________________________________
-
-GCC 3.2
-
- 3.2 is a small bug fix release, but there is a change to the
- application binary interface (ABI), hence the change to the second part
- of the version number.
-
- The main purpose of the 3.2 release is to correct a couple of problems
- in the C++ ABI, with the intention of providing a stable interface
- going forward. Accordingly, 3.2 is only a small change to 3.1.1.
-
- Bug Fixes
-
- C++
-
- * [233]7320: g++ 3.2 relocation problem
- * [234]7470: vtable: virtual function pointers not in declaration
- order
-
- libstdc++
-
- * [235]6410: Trouble with non-ASCII monetary symbols and wchar_t
- * [236]6503, [237]6642, [238]7186: Problems with comparing or
- subtracting various types of const and non-const iterators
- * [239]7216: ambiguity with basic_iostream::traits_type
- * [240]7220: problem with basic_istream::ignore(0,delimiter)
- * [241]7222: locale::operator==() doesn't work on std::locale("")
- * [242]7286: placement operator delete issue
- * [243]7442: cxxabi.h does not match the C++ ABI
- * [244]7445: poor performance of std::locale::classic() in
- multi-threaded applications
-
- x86-64 specific
-
- * [245]7291: off-by-one in generated inline bzero code for x86-64
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [246]GCC manuals. If that fails, the
- [247]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [248]gcc at gcc.gnu.org. All of [249]our lists have public
- archives.
-
- Copyright (C) [250]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [251]maintained by the GCC team. Last modified
- 2014-06-27[252].
-
-References
-
- 1. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.3
- 2. http://gcc.gnu.org/gcc-3.1/changes.html
- 3. http://gcc.gnu.org/gcc-3.2/c++-abi.html
- 4. https://gcc.gnu.org/PR3782
- 5. https://gcc.gnu.org/PR6440
- 6. https://gcc.gnu.org/PR7050
- 7. https://gcc.gnu.org/PR7741
- 8. https://gcc.gnu.org/PR7982
- 9. https://gcc.gnu.org/PR8068
- 10. https://gcc.gnu.org/PR8178
- 11. https://gcc.gnu.org/PR8396
- 12. https://gcc.gnu.org/PR8674
- 13. https://gcc.gnu.org/PR9768
- 14. https://gcc.gnu.org/PR9798
- 15. https://gcc.gnu.org/PR9799
- 16. https://gcc.gnu.org/PR9928
- 17. https://gcc.gnu.org/PR10114
- 18. https://gcc.gnu.org/PR10352
- 19. https://gcc.gnu.org/PR10336
- 20. https://gcc.gnu.org/PR8224
- 21. https://gcc.gnu.org/PR8613
- 22. https://gcc.gnu.org/PR8828
- 23. https://gcc.gnu.org/PR9226
- 24. https://gcc.gnu.org/PR9853
- 25. https://gcc.gnu.org/PR9797
- 26. https://gcc.gnu.org/PR9967
- 27. https://gcc.gnu.org/PR10116
- 28. https://gcc.gnu.org/PR10171
- 29. https://gcc.gnu.org/PR10175
- 30. https://gcc.gnu.org/PR8316
- 31. https://gcc.gnu.org/PR9169
- 32. https://gcc.gnu.org/PR9420
- 33. https://gcc.gnu.org/PR9459
- 34. https://gcc.gnu.org/PR9507
- 35. https://gcc.gnu.org/PR9538
- 36. https://gcc.gnu.org/PR9602
- 37. https://gcc.gnu.org/PR9993
- 38. https://gcc.gnu.org/PR10167
- 39. https://gcc.gnu.org/PR9652
- 40. https://gcc.gnu.org/PR10144
- 41. https://gcc.gnu.org/PR8746
- 42. https://gcc.gnu.org/PR9888
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- 95. https://gcc.gnu.org/PR8790
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- 97. https://gcc.gnu.org/PR9076
- 98. https://gcc.gnu.org/PR9151
- 99. https://gcc.gnu.org/PR9168
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- 101. https://gcc.gnu.org/PR9322
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- 108. https://gcc.gnu.org/PR9492
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- 113. https://gcc.gnu.org/PR9090
- 114. https://gcc.gnu.org/PR8588
- 115. https://gcc.gnu.org/PR8599
- 116. https://gcc.gnu.org/PR9506
- 117. https://gcc.gnu.org/PR9484
- 118. https://gcc.gnu.org/PR9292
- 119. https://gcc.gnu.org/PR9293
- 120. https://gcc.gnu.org/PR9295
- 121. https://gcc.gnu.org/PR9296
- 122. https://gcc.gnu.org/PR9316
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- 129. https://gcc.gnu.org/PR2521
- 130. https://gcc.gnu.org/PR5661
- 131. https://gcc.gnu.org/PR6419
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- 133. https://gcc.gnu.org/PR7150
- 134. https://gcc.gnu.org/PR7160
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- 137. https://gcc.gnu.org/PR7353
- 138. https://gcc.gnu.org/PR7411
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- 162. https://gcc.gnu.org/PR7811
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- 164. https://gcc.gnu.org/PR8071
- 165. https://gcc.gnu.org/PR8127
- 166. https://gcc.gnu.org/PR6745
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- 169. https://gcc.gnu.org/PR8218
- 170. https://gcc.gnu.org/PR8287
- 171. https://gcc.gnu.org/PR8347
- 172. https://gcc.gnu.org/PR8348
- 173. https://gcc.gnu.org/PR8391
- 174. https://gcc.gnu.org/PR6627
- 175. https://gcc.gnu.org/PR6631
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- 200. https://gcc.gnu.org/PR7242
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- 203. https://gcc.gnu.org/PR7693
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- 208. https://gcc.gnu.org/PR6984
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- 210. https://gcc.gnu.org/PR7130
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- 212. https://gcc.gnu.org/PR7380
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- 214. https://gcc.gnu.org/PR8451
- 215. https://gcc.gnu.org/PR7250
- 216. https://gcc.gnu.org/PR6668
- 217. https://gcc.gnu.org/PR7151
- 218. https://gcc.gnu.org/PR7335
- 219. https://gcc.gnu.org/PR7842
- 220. https://gcc.gnu.org/PR7856
- 221. https://gcc.gnu.org/PR7967
- 222. https://gcc.gnu.org/PR7374
- 223. https://gcc.gnu.org/PR7370
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- 225. https://gcc.gnu.org/PR8232
- 226. https://gcc.gnu.org/PR7623
- 227. https://gcc.gnu.org/PR8314
- 228. https://gcc.gnu.org/PR761
- 229. https://gcc.gnu.org/PR5610
- 230. https://gcc.gnu.org/PR7484
- 231. https://gcc.gnu.org/PR7531
- 232. https://gcc.gnu.org/PR8120
- 233. https://gcc.gnu.org/PR7320
- 234. https://gcc.gnu.org/PR7470
- 235. https://gcc.gnu.org/PR6410
- 236. https://gcc.gnu.org/PR6503
- 237. https://gcc.gnu.org/PR6642
- 238. https://gcc.gnu.org/PR7186
- 239. https://gcc.gnu.org/PR7216
- 240. https://gcc.gnu.org/PR7220
- 241. https://gcc.gnu.org/PR7222
- 242. https://gcc.gnu.org/PR7286
- 243. https://gcc.gnu.org/PR7442
- 244. https://gcc.gnu.org/PR7445
- 245. https://gcc.gnu.org/PR7291
- 246. https://gcc.gnu.org/onlinedocs/
- 247. mailto:gcc-help at gcc.gnu.org
- 248. mailto:gcc at gcc.gnu.org
- 249. https://gcc.gnu.org/lists.html
- 250. http://www.fsf.org/
- 251. https://gcc.gnu.org/about.html
- 252. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.1/index.html
- GCC 3.1
-
- July 27, 2002
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 3.1.1.
-
- The links below still apply to GCC 3.1.1.
-
- May 15, 2002
-
- The [2]GNU project and the GCC developers are pleased to announce the
- release of GCC 3.1.
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- A list of [3]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed [4]new features, improvements, bug fixes, and other changes
- as well as test results to GCC. This [5]amazing group of volunteers is
- what makes GCC successful.
-
- For additional information about GCC please refer to the [6]GCC project
- web site or contact the [7]GCC development mailing list.
-
- To obtain GCC please use [8]our mirror sites, or our CVS server.
- __________________________________________________________________
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [9]GCC manuals. If that fails, the
- [10]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [11]gcc at gcc.gnu.org. All of [12]our lists have public
- archives.
-
- Copyright (C) [13]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [14]maintained by the GCC team. Last modified
- 2014-06-28[15].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://www.gnu.org/
- 3. http://gcc.gnu.org/gcc-3.1/buildstat.html
- 4. http://gcc.gnu.org/gcc-3.1/changes.html
- 5. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 6. http://gcc.gnu.org/index.html
- 7. mailto:gcc at gcc.gnu.org
- 8. http://gcc.gnu.org/mirrors.html
- 9. https://gcc.gnu.org/onlinedocs/
- 10. mailto:gcc-help at gcc.gnu.org
- 11. mailto:gcc at gcc.gnu.org
- 12. https://gcc.gnu.org/lists.html
- 13. http://www.fsf.org/
- 14. https://gcc.gnu.org/about.html
- 15. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.1/changes.html
- GCC 3.1 Release Series
- Changes, New Features, and Fixes
-
-Additional changes in GCC 3.1.1
-
- * A bug related to how structures and unions are returned has been
- fixed for powerpc-*-netbsd*.
- * An important bug in the implementation of -fprefetch-loop-arrays
- has been fixed. Previously the optimization prefetched random
- blocks of memory for most targets except for i386.
- * The Java compiler now compiles Java programs much faster and also
- works with parallel make.
- * Nested functions have been fixed for mips*-*-netbsd*.
- * Some missing floating point support routines have beed added for
- mips*-*-netbsd*.
- * This [1]message gives additional information about the bugs fixed
- in this release.
-
-Caveats
-
- * The -traditional C compiler option has been deprecated and will be
- removed in GCC 3.3. (It remains possible to preprocess non-C code
- with the traditional preprocessor.)
- * The default debugging format for most ELF platforms (including
- GNU/Linux and FreeBSD; notable exception is Solaris) has changed
- from stabs to DWARF2. This requires GDB 5.1.1 or later.
-
-General Optimizer Improvements
-
- * Jan Hubicka, SuSE Labs, together with Richard Henderson, Red Hat,
- and Andreas Jaeger, SuSE Labs, has contributed [2]infrastructure
- for profile driven optimizations.
- Options -fprofile-arcs and -fbranch-probabilities can now be used
- to improve speed of the generated code by profiling the actual
- program behaviour on typical runs. In the absence of profile info
- the compiler attempts to guess the profile statically.
- * [3]SPEC2000 and SPEC95 benchmark suites are now used daily to
- monitor performance of the generated code.
- According to the SPECInt2000 results on an AMD Athlon CPU, the code
- generated by GCC 3.1 is 6% faster on the average (8.2% faster with
- profile feedback) compared to GCC 3.0. The code produced by GCC 3.0
- is about 2.1% faster compared to 2.95.3. Tests were done using the
- -O2 -march=athlon command-line options.
- * Alexandre Oliva, of Red Hat, has generalized the tree inlining
- infrastructure developed by CodeSourcery, LLC for the C++ front
- end, so that it is now used in the C front end too. Inlining
- functions as trees exposes them earlier to the compiler, giving it
- more opportunities for optimization.
- * Support for data prefetching instructions has been added to the GCC
- back end and several targets. A new __builtin_prefetch intrinsic is
- available to explicitly insert prefetch instructions and
- experimental support for loop array prefetching has been added (see
- -fprefetch-loop-array documentation).
- * Support for emitting debugging information for macros has been
- added for DWARF2. It is activated using -g3.
-
-New Languages and Language specific improvements
-
- C/C++
-
- * A few more [4]ISO C99 features.
- * The preprocessor is 10-50% faster than the preprocessor in GCC 3.0.
- * The preprocessor's symbol table has been merged with the symbol
- table of the C, C++ and Objective-C front ends.
- * The preprocessor consumes less memory than the preprocessor in GCC
- 3.0, often significantly so. On normal input files, it typically
- consumes less memory than pre-3.0 cccp-based GCC, too.
-
- C++
-
- * -fhonor-std and -fno-honor-std have been removed. -fno-honor-std
- was a workaround to allow std compliant code to work with the
- non-std compliant libstdc++-v2. libstdc++-v3 is std compliant.
- * The C++ ABI has been fixed so that void (A::*)() const is mangled
- as "M1AKFvvE", rather than "MK1AFvvE" as before. This change only
- affects pointer to cv-qualified member function types.
- * The C++ ABI has been changed to correctly handle this code:
- struct A {
- void operator delete[] (void *, size_t);
- };
-
- struct B : public A {
- };
-
- new B[10];
-
- The amount of storage allocated for the array will be greater than
- it was in 3.0, in order to store the number of elements in the
- array, so that the correct size can be passed to operator delete[]
- when the array is deleted. Previously, the value passed to operator
- delete[] was unpredictable.
- This change will only affect code that declares a two-argument
- operator delete[] with a second parameter of type size_t in a base
- class, and does not override that definition in a derived class.
- * The C++ ABI has been changed so that:
- struct A {
- void operator delete[] (void *, size_t);
- void operator delete[] (void *);
- };
-
- does not cause unnecessary storage to be allocated when an array of
- A objects is allocated.
- This change will only affect code that declares both of these forms
- of operator delete[], and declared the two-argument form before the
- one-argument form.
- * The C++ ABI has been changed so that when a parameter is passed by
- value, any cleanup for that parameter is performed in the caller,
- as specified by the ia64 C++ ABI, rather than the called function
- as before. As a result, classes with a non-trivial destructor but a
- trivial copy constructor will be passed and returned by invisible
- reference, rather than by bitwise copy as before.
- * G++ now supports the "named return value optimization": for code
- like
- A f () {
- A a;
- ...
- return a;
- }
-
- G++ will allocate a in the return value slot, so that the return
- becomes a no-op. For this to work, all return statements in the
- function must return the same variable.
- * Improvements to the C++ library are listed in [5]the libstdc++-v3
- FAQ.
-
- Objective-C
-
- * Annoying linker warnings (due to incorrect code being generated)
- have been fixed.
- * If a class method cannot be found, the compiler no longer issues a
- warning if a corresponding instance method exists in the root
- class.
- * Forward @protocol declarations have been fixed.
- * Loading of categories has been fixed in certain situations (GNU run
- time only).
- * The class lookup in the run-time library has been rewritten so that
- class method dispatch is more than twice as fast as it used to be
- (GNU run time only).
-
- Java
-
- * libgcj now includes RMI, java.lang.ref.*, javax.naming, and
- javax.transaction.
- * Property files and other system resources can be compiled into
- executables which use libgcj using the new gcj --resource feature.
- * libgcj has been ported to more platforms. In particular there is
- now a mostly-functional mingw32 (Windows) target port.
- * JNI and CNI invocation interfaces were implemented, so gcj-compiled
- Java code can now be called from a C/C++ application.
- * gcj can now use builtin functions for certain known methods, for
- instance Math.cos.
- * gcj can now automatically remove redundant array-store checks in
- some common cases.
- * The --no-store-checks optimization option was added. This can be
- used to omit runtime store checks for code which is known not to
- throw ArrayStoreException
- * The following third party interface standards were added to libgcj:
- org.w3c.dom and org.xml.sax.
- * java.security has been merged with GNU Classpath. The new package
- is now JDK 1.2 compliant, and much more complete.
- * A bytecode verifier was added to the libgcj interpreter.
- * java.lang.Character was rewritten to comply with the Unicode 3.0
- standard, and improve performance.
- * Partial support for many more locales was added to libgcj.
- * Socket timeouts have been implemented.
- * libgcj has been merged into a single shared library. There are no
- longer separate shared libraries for the garbage collector and
- zlib.
- * Several performance improvements were made to gcj and libgcj:
- + Hash synchronization (thin locks)
- + A special allocation path for finalizer-free objects
- + Thread-local allocation
- + Parallel GC, and other GC tweaks
-
- Fortran
-
- Fortran improvements are listed in [6]the Fortran documentation.
-
- Ada
-
- [7]Ada Core Technologies, Inc, has contributed its GNAT Ada 95 front
- end and associated tools. The GNAT compiler fully implements the Ada
- language as defined by the ISO/IEC 8652 standard.
-
- Please note that the integration of the Ada front end is still work in
- progress.
-
-New Targets and Target Specific Improvements
-
- * Hans-Peter Nilsson has contributed a port to [8]MMIX, the CPU
- architecture used in new editions of Donald E. Knuth's The Art of
- Computer Programming.
- * [9]Axis Communications has contributed its port to the CRIS CPU
- architecture, used in the ETRAX system-on-a-chip series. See
- [10]Axis' developer site for technical information.
- * Alexandre Oliva, of Red Hat, has contributed a port to the
- [11]SuperH SH5 64-bit RISC microprocessor architecture, extending
- the existing SH port.
- * UltraSPARC is fully supported in 64-bit mode. The option -m64
- enables it.
- * For compatibility with the Sun compiler #pragma redefine_extname
- has been implemented on Solaris.
- * The x86 back end has had some noticeable work done to it.
- + SuSE Labs developers Jan Hubicka, Bo Thorsen and Andreas
- Jaeger have contributed a port to the AMD x86-64 architecture.
- For more information on x86-64 see [12]http://www.x86-64.org.
- + The compiler now supports MMX, 3DNow!, SSE, and SSE2
- instructions. Options -mmmx, -m3dnow, -msse, and -msse2 will
- enable the respective instruction sets. Intel C++ compatible
- MMX/3DNow!/SSE intrinsics are implemented. SSE2 intrinsics
- will be added in next major release.
- + Following those improvements, targets for Pentium MMX, K6-2,
- K6-3, Pentium III, Pentium 4, and Athlon 4 Mobile/XP/MP were
- added. Refer to the documentation on -march= and -mcpu=
- options for details.
- + For those targets that support it, -mfpmath=sse will cause the
- compiler to generate SSE/SSE2 instructions for floating point
- math instead of x87 instructions. Usually, this will lead to
- quicker code — especially on the Pentium 4. Note that only
- scalar floating point instructions are used and GCC does not
- exploit SIMD features yet.
- + Prefetch support has been added to the Pentium III, Pentium 4,
- K6-2, K6-3, and Athlon series.
- + Code generated for floating point to integer conversions has
- been improved leading to better performance of many 3D
- applications.
- * The PowerPC back end has added 64-bit PowerPC GNU/Linux support.
- * C++ support for AIX has been improved.
- * Aldy Hernandez, of Red Hat, Inc, has contributed extensions to the
- PowerPC port supporting the AltiVec programming model (SIMD). The
- support, though presently useful, is experimental and is expected
- to stabilize for 3.2. The support is written to conform to
- Motorola's AltiVec specs. See -maltivec.
-
-Obsolete Systems
-
- Support for a number of older systems has been declared obsolete in GCC
- 3.1. Unless there is activity to revive them, the next release of GCC
- will have their sources permanently removed.
-
- All configurations of the following processor architectures have been
- declared obsolete:
- * MIL-STD-1750A, 1750a-*-*
- * AMD A29k, a29k-*-*
- * Convex, c*-convex-*
- * Clipper, clipper-*-*
- * Elxsi, elxsi-*-*
- * Intel i860, i860-*-*
- * Sun picoJava, pj-*-* and pjl-*-*
- * Western Electric 32000, we32k-*-*
-
- Most configurations of the following processor architectures have been
- declared obsolete, but we are preserving a few systems which may have
- active developers. It is unlikely that the remaining systems will
- survive much longer unless we see definite signs of port activity.
- * Motorola 88000 except
- + Generic a.out, m88k-*-aout*
- + Generic SVR4, m88k-*-sysv4
- + OpenBSD, m88k-*-openbsd*
- * NS32k except
- + NetBSD, ns32k-*-netbsd*
- + OpenBSD, ns32k-*-openbsd*.
- * ROMP except
- + OpenBSD, romp-*-openbsd*.
-
- Finally, only some configurations of these processor architectures are
- being obsoleted.
- * Alpha:
- + OSF/1, alpha*-*-osf[123]*. (Digital Unix and Tru64 Unix, aka
- alpha*-*-osf[45], are still supported.)
- * ARM:
- + RISCiX, arm-*-riscix*.
- * i386:
- + 386BSD, i?86-*-bsd*
- + Chorus, i?86-*-chorusos*
- + DG/UX, i?86-*-dgux*
- + FreeBSD 1.x, i?86-*-freebsd1.*
- + IBM AIX, i?86-*-aix*
- + ISC UNIX, i?86-*-isc*
- + GNU/Linux with pre-BFD linker, i?86-*-linux*oldld*
- + NEXTstep, i?86-next-*
- + OSF UNIX, i?86-*-osf1* and i?86-*-osfrose*
- + RTEMS/coff, i?86-*-rtemscoff*
- + RTEMS/go32, i?86-go32-rtems*
- + Sequent/BSD, i?86-sequent-bsd*
- + Sequent/ptx before version 3, i?86-sequent-ptx[12]* and
- i?86-sequent-sysv3*
- + SunOS, i?86-*-sunos*
- * Motorola 68000:
- + Altos, m68[k0]*-altos-*
- + Apollo, m68[k0]*-apollo-*
- + Apple A/UX, m68[k0]*-apple-*
- + Bull, m68[k0]*-bull-*
- + Convergent, m68[k0]*-convergent-*
- + Generic SVR3, m68[k0]*-*-sysv3*
- + ISI, m68[k0]*-isi-*
- + LynxOS, m68[k0]*-*-lynxos*
- + NEXT, m68[k0]*-next-*
- + RTEMS/coff, m68[k0]*-*-rtemscoff*
- + Sony, m68[k0]*-sony-*
- * MIPS:
- + DEC Ultrix, mips-*-ultrix* and mips-dec-*
- + Generic BSD, mips-*-bsd*
- + Generic System V, mips-*-sysv*
- + IRIX before version 5, mips-sgi-irix[1234]*
- + RiscOS, mips-*-riscos*
- + Sony, mips-sony-*
- + Tandem, mips-tandem-*
- * SPARC:
- + RTEMS/a.out, sparc-*-rtemsaout*.
-
-Documentation improvements
-
- * The old manual ("Using and Porting the GNU Compiler Collection")
- has been replaced by a users manual ("Using the GNU Compiler
- Collection") and a separate internals reference manual ("GNU
- Compiler Collection Internals").
- * More complete and much improved documentation about GCC's internal
- representation used by the C and C++ front ends.
- * Many cleanups and improvements in general.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [13]GCC manuals. If that fails, the
- [14]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [15]gcc at gcc.gnu.org. All of [16]our lists have public
- archives.
-
- Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [18]maintained by the GCC team. Last modified
- 2014-06-28[19].
-
-References
-
- 1. https://gcc.gnu.org/ml/gcc/2002-07/msg01208.html
- 2. http://gcc.gnu.org/news/profiledriven.html
- 3. http://gcc.gnu.org/benchmarks/
- 4. http://gcc.gnu.org/c99status.html
- 5. https://gcc.gnu.org/onlinedocs/libstdc++/faq.html
- 6. https://gcc.gnu.org/onlinedocs/gcc-3.1.1/g77/News.html
- 7. http://www.adacore.com/
- 8. http://www-cs-faculty.stanford.edu/~knuth/mmix.html
- 9. http://www.axis.com/
- 10. http://developer.axis.com/
- 11. http://www.superh.com/
- 12. http://www.x86-64.org/
- 13. https://gcc.gnu.org/onlinedocs/
- 14. mailto:gcc-help at gcc.gnu.org
- 15. mailto:gcc at gcc.gnu.org
- 16. https://gcc.gnu.org/lists.html
- 17. http://www.fsf.org/
- 18. https://gcc.gnu.org/about.html
- 19. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.0/index.html
- GCC 3.0.4
-
- February 20, 2002
-
- The [1]GNU project and the GCC developers are pleased to announce the
- release of GCC 3.0.4, which is a bug-fix release for the GCC 3.0
- series.
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- GCC 3.0.x has several new optimizations, new targets, new languages and
- many other new features, relative to GCC 2.95.x. See the [2]new
- features page for a more complete list.
-
- A list of [3]successful builds is updated as new information becomes
- available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, test results, bug fixes, etc to GCC. This
- [4]amazing group of volunteers is what makes GCC successful.
-
- And finally, we can't in good conscience fail to mention some
- [5]caveats to using GCC 3.0.x.
-
- For additional information about GCC please refer to the [6]GCC project
- web site or contact the [7]GCC development mailing list.
-
- To obtain GCC please use [8]our mirror sites, or our CVS server.
- __________________________________________________________________
-
-Previous 3.0.x Releases
-
- December 20, 2001: GCC 3.0.3 has been released.
- October 25, 2001: GCC 3.0.2 has been released.
- August 20, 2001: GCC 3.0.1 has been released.
- June 18, 2001: GCC 3.0 has been released.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [9]GCC manuals. If that fails, the
- [10]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [11]gcc at gcc.gnu.org. All of [12]our lists have public
- archives.
-
- Copyright (C) [13]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [14]maintained by the GCC team. Last modified
- 2014-06-28[15].
-
-References
-
- 1. http://www.gnu.org/
- 2. http://gcc.gnu.org/gcc-3.0/features.html
- 3. http://gcc.gnu.org/gcc-3.0/buildstat.html
- 4. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 5. http://gcc.gnu.org/gcc-3.0/caveats.html
- 6. http://gcc.gnu.org/index.html
- 7. mailto:gcc at gcc.gnu.org
- 8. http://gcc.gnu.org/mirrors.html
- 9. https://gcc.gnu.org/onlinedocs/
- 10. mailto:gcc-help at gcc.gnu.org
- 11. mailto:gcc at gcc.gnu.org
- 12. https://gcc.gnu.org/lists.html
- 13. http://www.fsf.org/
- 14. https://gcc.gnu.org/about.html
- 15. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.0/features.html
- GCC 3.0 New Features
-
-Additional changes in GCC 3.0.4
-
- * GCC 3.0 now supports newer versions of the [1]NetBSD operating
- system, which use the ELF object file format, on x86 processors.
- * Correct debugging information is generated from functions that have
- lines from multiple files (e.g. yacc output).
- * A fix for whitespace handling in the -traditional preprocessor,
- which can affect Fortran.
- * Fixes to the exception handling runtime.
- * More fixes for bad code generation in C++.
- * A fix for shared library generation under AIX 4.3.
- * Documentation updates.
- * Port of GCC to Tensilica's Xtensa processor contributed.
- * A fix for compiling the PPC Linux kernel (FAT fs wouldn't link).
-
-Additional changes in GCC 3.0.3
-
- * A fix to correct an accidental change to the PowerPC ABI.
- * Fixes for bad code generation on a variety of architectures.
- * Improvements to the debugging information generated for C++
- classes.
- * Fixes for bad code generation in C++.
- * A fix to avoid crashes in the C++ demangler.
- * A fix to the C++ standard library to avoid buffer overflows.
- * Miscellaneous improvements for a variety of architectures.
-
-Additional changes in GCC 3.0.2
-
- * Fixes for bad code generation during loop unrolling.
- * Fixes for bad code generation by the sibling call optimization.
- * Minor improvements to x86 code generation.
- * Implementation of function descriptors in C++ vtables for IA64.
- * Numerous minor bug-fixes.
-
-Additional changes in GCC 3.0.1
-
- * C++ fixes for incorrect code-generation.
- * Improved cross-compiling support for the C++ standard library.
- * Fixes for some embedded targets that worked in GCC 2.95.3, but not
- in GCC 3.0.
- * Fixes for various exception-handling bugs.
- * A port to the S/390 architecture.
-
-General Optimizer Improvements
-
- * [2]Basic block reordering pass.
- * New if-conversion pass with support for conditional (predicated)
- execution.
- * New tail call and sibling call elimination optimizations.
- * New register renaming pass.
- * New (experimental) [3]static single assignment (SSA) representation
- support.
- * New dead-code elimination pass implemented using the SSA
- representation.
- * [4]Global null pointer test elimination.
- * [5]Global code hoisting/unification.
- * More builtins and optimizations for stdio.h, string.h and old BSD
- functions, as well as for ISO C99 functions.
- * New builtin __builtin_expect for giving hints to the branch
- predictor.
-
-New Languages and Language specific improvements
-
- * The GNU Compiler for the Java(TM) language (GCJ) is now integrated
- and supported, including the run-time library containing most
- common non-GUI Java classes, a bytecode interpreter, and the Boehm
- conservative garbage collector. Many bugs have been fixed. GCJ can
- compile Java source or Java bytecodes to either native code or Java
- class files, and supports native methods written in either the
- standard JNI or the more efficient and convenient CNI.
- * Here is a [6]partial list of C++ improvements, both new features
- and those no longer supported.
- * New C++ ABI. On the IA-64 platform GCC is capable of
- inter-operating with other IA-64 compilers.
- * The new ABI also significantly reduces the size of symbol and debug
- information.
- * New [7]C++ support library and many C++ bug fixes, vastly improving
- our conformance to the ISO C++ standard.
- * New [8]inliner for C++.
- * Rewritten C preprocessor, integrated into the C, C++ and Objective
- C compilers, with very many improvements including ISO C99 support
- and [9]improvements to dependency generation.
- * Support for more [10]ISO C99 features.
- * Many improvements to support for checking calls to format functions
- such as printf and scanf, including support for ISO C99 format
- features, extensions from the Single Unix Specification and GNU
- libc 2.2, checking of strfmon formats and features to assist in
- auditing for format string security bugs.
- * New warnings for C code that may have undefined semantics because
- of violations of sequence point rules in the C standard (such as a
- = a++;, a[n] = b[n++]; and a[i++] = i;), included in -Wall.
- * Additional warning option -Wfloat-equal.
- * Improvements to -Wtraditional.
- * Fortran improvements are listed in [11]the Fortran documentation.
-
-New Targets and Target Specific Improvements
-
- * New x86 back end, generating much improved code.
- * Support for a generic i386-elf target contributed.
- * New option to emit x86 assembly code using Intel style syntax
- (-mintel-syntax).
- * HPUX 11 support contributed.
- * Improved PowerPC code generation, including scheduled prologue and
- epilogue.
- * Port of GCC to Intel's IA-64 processor contributed.
- * Port of GCC to Motorola's MCore 210 and 340 contributed.
- * New unified back-end for Arm, Thumb and StrongArm contributed.
- * Port of GCC to Intel's XScale processor contributed.
- * Port of GCC to Atmel's AVR microcontrollers contributed.
- * Port of GCC to Mitsubishi's D30V processor contributed.
- * Port of GCC to Matsushita's AM33 processor (a member of the MN10300
- processor family) contributed.
- * Port of GCC to Fujitsu's FR30 processor contributed.
- * Port of GCC to Motorola's 68HC11 and 68HC12 processors contributed.
- * Port of GCC to Sun's picoJava processor core contributed.
-
-Documentation improvements
-
- * Substantially rewritten and improved C preprocessor manual.
- * Many improvements to other documentation.
- * Manpages for gcc, cpp and gcov are now generated automatically from
- the master Texinfo manual, eliminating the problem of manpages
- being out of date. (The generated manpages are only extracts from
- the full manual, which is provided in Texinfo form, from which
- info, HTML, other formats and a printed manual can be generated.)
- * Generated info files are included in the release tarballs alongside
- their Texinfo sources, avoiding problems on some platforms with
- building makeinfo as part of the GCC distribution.
-
-Other significant improvements
-
- * Garbage collection used internally by the compiler for most memory
- allocation instead of obstacks.
- * Lengauer and Tarjan algorithm used for computing dominators in the
- CFG. This algorithm can be significantly faster and more space
- efficient than our older algorithm.
- * gccbug script provided to assist in submitting bug reports to our
- bug tracking system. (Bug reports previously submitted directly to
- our mailing lists, for which you received no bug tracking number,
- should be submitted again using gccbug if you can reproduce the
- problem with GCC 3.0.)
- * The internal libgcc library is [12]built as a shared library on
- systems that support it.
- * Extensive testsuite included with GCC, with many new tests. In
- addition to tests for GCC bugs that have been fixed, many tests
- have been added for language features, compiler warnings and
- builtin functions.
- * Additional language-independent warning options -Wpacked, -Wpadded,
- -Wunreachable-code and -Wdisabled-optimization.
- * Target-independent options -falign-functions, -falign-loops and
- -falign-jumps.
-
- Plus a great many bug fixes and almost all the [13]features found in
- GCC 2.95.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [14]GCC manuals. If that fails, the
- [15]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [16]gcc at gcc.gnu.org. All of [17]our lists have public
- archives.
-
- Copyright (C) [18]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [19]maintained by the GCC team. Last modified
- 2014-06-28[20].
-
-References
-
- 1. http://www.netbsd.org/
- 2. http://gcc.gnu.org/news/reorder.html
- 3. http://gcc.gnu.org/news/ssa.html
- 4. http://gcc.gnu.org/news/null.html
- 5. http://gcc.gnu.org/news/unify.html
- 6. http://gcc.gnu.org/gcc-3.0/c++features.html
- 7. http://gcc.gnu.org/libstdc++/
- 8. http://gcc.gnu.org/news/inlining.html
- 9. http://gcc.gnu.org/news/dependencies.html
- 10. http://gcc.gnu.org/c99status.html
- 11. https://gcc.gnu.org/onlinedocs/gcc-3.4.6/g77/News.html
- 12. http://gcc.gnu.org/gcc-3.0/libgcc.html
- 13. http://gcc.gnu.org/gcc-2.95/features.html
- 14. https://gcc.gnu.org/onlinedocs/
- 15. mailto:gcc-help at gcc.gnu.org
- 16. mailto:gcc at gcc.gnu.org
- 17. https://gcc.gnu.org/lists.html
- 18. http://www.fsf.org/
- 19. https://gcc.gnu.org/about.html
- 20. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-3.0/caveats.html
- GCC 3.0 Caveats
-
- * -fstrict-aliasing is now part of -O2 and higher optimization
- levels. This allows the compiler to assume the strictest aliasing
- rules applicable to the language being compiled. For C and C++,
- this activates optimizations based on the type of expressions. This
- optimization may thus break old, non-compliant code.
- * Enumerations are now properly promoted to int in function
- parameters and function returns. Normally this change is not
- visible, but when using -fshort-enums this is an ABI change.
- * The undocumented extension that allowed C programs to have a label
- at the end of a compound statement has been deprecated and may be
- removed in a future version. Programs that now generate a warning
- about this may be fixed by adding a null statement (a single
- semicolon) after the label.
- * The poorly documented extension that allowed string constants in C,
- C++ and Objective C to contain unescaped newlines has been
- deprecated and may be removed in a future version. Programs using
- this extension may be fixed in several ways: the bare newline may
- be replaced by \n, or preceded by \n\, or string concatenation may
- be used with the bare newline preceded by \n" and " placed at the
- start of the next line.
- * The Chill compiler is not included in GCC 3.0, because of the lack
- of a volunteer to convert it to use garbage collection.
- * Certain non-standard iostream methods from earlier versions of
- libstdc++ are not included in libstdc++ v3, i.e. filebuf::attach,
- ostream::form, and istream::gets.
- * The new C++ ABI is not yet fully supported by current (as of
- 2001-07-01) releases and development versions of GDB, or any
- earlier versions. There is a problem setting breakpoints by line
- number, and other related issues that have been fixed in GCC 3.0
- but not yet handled in GDB:
- [1]https://gcc.gnu.org/ml/gcc-bugs/2001-06/msg00421.html
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [2]GCC manuals. If that fails, the
- [3]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [4]gcc at gcc.gnu.org. All of [5]our lists have public archives.
-
- Copyright (C) [6]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [7]maintained by the GCC team. Last modified
- 2014-06-27[8].
-
-References
-
- 1. https://gcc.gnu.org/ml/gcc-bugs/2001-06/msg00421.html
- 2. https://gcc.gnu.org/onlinedocs/
- 3. mailto:gcc-help at gcc.gnu.org
- 4. mailto:gcc at gcc.gnu.org
- 5. https://gcc.gnu.org/lists.html
- 6. http://www.fsf.org/
- 7. https://gcc.gnu.org/about.html
- 8. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-2.95/index.html
- GCC 2.95
-
- March 16, 2001: The GNU project and the GCC developers are pleased to
- announce the release of GCC version 2.95.3.
-
-Release History
-
- GCC 2.95.3
- March 16, 2001
-
- GCC 2.95.2
- October 27, 1999
-
- GCC 2.95.1
- August 19, 1999
-
- GCC 2.95
- July 31, 1999. This is the first release of GCC since the April
- 1999 GCC/EGCS reunification and includes nearly a year's worth
- of new development and bugfixes.
-
-References and Acknowledgements
-
- GCC used to stand for the GNU C Compiler, but since the compiler
- supports several other languages aside from C, it now stands for the
- GNU Compiler Collection.
-
- The whole suite has been extensively [1]regression tested and
- [2]package tested. It should be reliable and suitable for widespread
- use.
-
- The compiler has several new optimizations, new targets, new languages
- and other new features. See the [3]new features page for a more
- complete list of new features found in the GCC 2.95 releases.
-
- The sources include installation instructions in both HTML and
- plaintext forms in the install directory in the distribution. However,
- the most up to date installation instructions and [4]build/test status
- are on the web pages. We will update those pages as new information
- becomes available.
-
- The GCC developers would like to thank the numerous people that have
- contributed new features, test results, bugfixes, etc to GCC. This
- [5]amazing group of volunteers is what makes GCC successful.
-
- And finally, we can't in good conscience fail to mention some
- [6]caveats to using GCC 2.95.
-
- Download GCC 2.95 from one of our many [7]mirror sites.
-
- For additional information about GCC please see the [8]GCC project web
- server or contact the [9]GCC development mailing list.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [10]GCC manuals. If that fails, the
- [11]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [12]gcc at gcc.gnu.org. All of [13]our lists have public
- archives.
-
- Copyright (C) [14]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [15]maintained by the GCC team. Last modified
- 2014-06-28[16].
-
-References
-
- 1. http://gcc.gnu.org/gcc-2.95/regress.html
- 2. http://gcc.gnu.org/gcc-2.95/othertest.html
- 3. http://gcc.gnu.org/gcc-2.95/features.html
- 4. http://gcc.gnu.org/gcc-2.95/buildstat.html
- 5. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 6. http://gcc.gnu.org/gcc-2.95/caveats.html
- 7. http://gcc.gnu.org/mirrors.html
- 8. http://gcc.gnu.org/index.html
- 9. mailto:gcc at gcc.gnu.org
- 10. https://gcc.gnu.org/onlinedocs/
- 11. mailto:gcc-help at gcc.gnu.org
- 12. mailto:gcc at gcc.gnu.org
- 13. https://gcc.gnu.org/lists.html
- 14. http://www.fsf.org/
- 15. https://gcc.gnu.org/about.html
- 16. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-2.95/features.html
- GCC 2.95 New Features
-
- * General Optimizer Improvements:
- + [1]Localized register spilling to improve speed and code
- density especially on small register class machines.
- + [2]Global CSE using lazy code motion algorithms.
- + [3]Improved global constant/copy propagation.
- + [4]Improved control flow graph analysis and manipulation.
- + [5]Local dead store elimination.
- + [6]Memory Load hoisting/store sinking in loops.
- + [7]Type based alias analysis is enabled by default. Note this
- feature will expose bugs in the Linux kernel. Please refer to
- the FAQ (as shipped with GCC 2.95) for additional information
- on this issue.
- + Major revamp of GIV detection, combination and simplification
- to improve loop performance.
- + Major improvements to register allocation and reloading.
- * New Languages and Language specific improvements
- + [8]Many C++ improvements.
- + [9]Many Fortran improvements.
- + [10]Java front-end has been integrated. [11]runtime library is
- available separately.
- + [12]ISO C99 support
- + [13]Chill front-end and runtime has been integrated.
- + Boehm garbage collector support in libobjc.
- + More support for various pragmas which appear in vendor
- include files
- * New Targets and Target Specific Improvements
- + [14]SPARC backend rewrite.
- + -mschedule=8000 will optimize code for PA8000 class
- processors; -mpa-risc-2-0 will generate code for PA2.0
- processors
- + Various micro-optimizations for the ia32 port. K6
- optimizations
- + Compiler will attempt to align doubles in the stack on the
- ia32 port
- + Alpha EV6 support
- + PowerPC 750
- + RS6000/PowerPC: -mcpu=401 was added as an alias for -mcpu=403.
- -mcpu=e603e was added to do -mcpu=603e and -msoft-float.
- + c3x, c4x
- + HyperSPARC
- + SparcLite86x
- + sh4
- + Support for new systems (OpenBSD, FreeBSD, UWIN, Interix,
- arm-linux)
- + vxWorks targets include support for vxWorks threads
- + StrongARM 110 and ARM9 support added. ARM Scheduling
- parameters rewritten.
- + Various changes to the MIPS port to avoid assembler macros,
- which in turn improves performance
- + Various performance improvements to the i960 port.
- + Major rewrite of ns32k port
- * Other significant improvements
- + [15]Ability to dump cfg information and display it using vcg.
- + The new faster scheme for fixing vendor header files is
- enabled by default.
- + Experimental internationalization support.
- + multibyte character support
- + Some compile-time speedups for pathological problems
- + Better support for complex types
- * Plus the usual mountain of bugfixes
- * Core compiler is based on the gcc2 development tree from Sept 30,
- 1998, so we have all of the [16]features found in GCC 2.8.
-
-Additional Changes in GCC 2.95.1
-
- * Generic bugfixes and improvements
- + Various documentation fixes related to the GCC/EGCS merger.
- + Fix memory management bug which could lead to spurious aborts,
- core dumps or random parsing errors in the compiler.
- + Fix a couple bugs in the dwarf1 and dwarf2 debug record
- support.
- + Fix infinite loop in the CSE optimizer.
- + Avoid undefined behavior in compiler FP emulation code
- + Fix install problem when prefix is overridden on the make
- install command.
- + Fix problem with unwanted installation of assert.h on some
- systems.
- + Fix problem with finding the wrong assembler in a single tree
- build.
- + Avoid increasing the known alignment of a register that is
- already known to be a pointer.
- * Platform specific bugfixes and improvements
- + Codegen bugfix for prologue/epilogue for cpu32 target.
- + Fix long long code generation bug for the Coldfire target.
- + Fix various aborts in the SH compiler.
- + Fix bugs in libgcc support library for the SH.
- + Fix alpha ev6 code generation bug.
- + Fix problems with EXIT_SUCCESS/EXIT_FAILURE redefinitions on
- AIX platforms.
- + Fix -fpic code generation bug for rs6000/ppc svr4 targets.
- + Fix varargs/stdarg code generation bug for rs6000/ppc svr4
- targets.
- + Fix weak symbol handling for rs6000/ppc svr4 targets.
- + Fix various problems with 64bit code generation for the
- rs6000/ppc port.
- + Fix codegen bug which caused tetex to be mis-compiled on the
- x86.
- + Fix compiler abort in new cfg code exposed by x86 port.
- + Fix out of range array reference in code convert flat
- registers to the x87 stacked FP register file.
- + Fix minor vxworks configuration bug.
- + Fix return type of bsearch for SunOS 4.x.
- * Language & Runtime specific fixes.
- + The G++ signature extension has been deprecated. It will be
- removed in the next major release of G++. Use of signatures
- will result in a warning from the compiler.
- + Several bugs relating to templates and namespaces were fixed.
- + A bug that caused crashes when combining templates with -g on
- DWARF1 platforms was fixed.
- + Pointers-to-members, virtual functions, and multiple
- inheritance should now work together correctly.
- + Some code-generation bugs relating to function try blocks were
- fixed.
- + G++ is a little bit more lenient with certain archaic
- constructs than in GCC 2.95.
- + Fix to prevent shared library version #s from bring truncated
- to 1 digit
- + Fix missing std:: in the libstdc++ library.
- + Fix stream locking problems in libio.
- + Fix problem in java compiler driver.
-
-Additional Changes in GCC 2.95.2
-
- The -fstrict-aliasing is not enabled by default for GCC 2.95.2. While
- the optimizations performed by -fstrict-aliasing are valid according to
- the C and C++ standards, the optimization have caused some problems,
- particularly with old non-conforming code.
-
- The GCC developers are experimenting with ways to warn users about code
- which violates the C/C++ standards, but those warnings are not ready
- for widespread use at this time. Rather than wait for those warnings
- the GCC developers have chosen to disable -fstrict-aliasing by default
- for the GCC 2.95.2 release.
-
- We strongly encourage developers to find and fix code which violates
- the C/C++ standards as -fstrict-aliasing may be enabled by default in
- future releases. Use the option -fstrict-aliasing to re-enable these
- optimizations.
- * Generic bugfixes and improvements
- + Fix incorrectly optimized memory reference in global common
- subexpression elimination (GCSE) optimization pass.
- + Fix code generation bug in regmove.c in which it could
- incorrectly change a "const" value.
- + Fix bug in optimization of conditionals involving volatile
- memory references.
- + Avoid over-allocation of stack space for some procedures.
- + Fixed bug in the compiler which caused incorrect optimization
- of an obscure series of bit manipulations, shifts and
- arithmetic.
- + Fixed register allocator bug which caused teTeX to be
- mis-compiled on SPARC targets.
- + Avoid incorrect optimization of degenerate case statements for
- certain targets such as the ARM.
- + Fix out of range memory reference in the jump optimizer.
- + Avoid dereferencing null pointer in fix-header.
- + Fix test for GCC specific features so that it is possible to
- bootstrap with gcc-2.6.2 and older versions of GCC.
- + Fix typo in scheduler which could potentially cause out of
- range memory accesses.
- + Avoid incorrect loop reversal which caused incorrect code for
- certain loops on PowerPC targets.
- + Avoid incorrect optimization of switch statements on certain
- targets (for example the ARM).
- * Platform specific bugfixes and improvements
- + Work around bug in Sun V5.0 compilers which caused bootstrap
- comparison failures on SPARC targets.
- + Fix SPARC backend bug which caused aborts in final.c.
- + Fix sparc-hal-solaris2* configuration fragments.
- + Fix bug in sparc block profiling.
- + Fix obscure code generation bug for the PARISC targets.
- + Define __STDC_EXT__ for HPUX configurations.
- + Various POWERPC64 code generation bugfixes.
- + Fix abort for PPC targets using ELF (ex GNU/Linux).
- + Fix collect2 problems for AIX targets.
- + Correct handling of .file directive for PPC targets.
- + Fix bug in fix_trunc x86 patterns.
- + Fix x86 port to correctly pop the FP stack for functions that
- return structures in memory.
- + Fix minor bug in strlen x86 pattern.
- + Use stabs debugging instead of dwarf1 for x86-solaris targets.
- + Fix template repository code to handle leading underscore in
- mangled names.
- + Fix weak/weak alias support for OpenBSD.
- + GNU/Linux for the ARM has C++ compatible include files.
- * Language & Runtime specific fixes.
- + Fix handling of constructor attribute in the C front-end which
- caused problems building the Chill runtime library on some
- targets.
- + Fix minor problem merging type qualifiers in the C front-end.
- + Fix aliasing bug for pointers and references (C/C++).
- + Fix incorrect "non-constant initializer bug" when -traditional
- or -fwritable-strings is enabled.
- + Fix build error for Chill front-end on SunOS.
- + Do not complain about duplicate instantiations when using
- -frepo (C++).
- + Fix array bounds handling in C++ front-end which caused
- problems with dwarf debugging information in some
- circumstances.
- + Fix minor namespace problem.
- + Fix problem linking java programs.
-
-Additional Changes in GCC 2.95.3
-
- * Generic bugfixes and improvements
- + Fix numerous problems that caused incorrect optimization in
- the register reloading code.
- + Fix numerous problems that caused incorrect optimization in
- the loop optimizer.
- + Fix aborts in the functions build_insn_chain and scan_loops
- under some circumstances.
- + Fix an alias analysis bug.
- + Fix an infinite compilation bug in the combiner.
- + A few problems with complex number support have been fixed.
- + It is no longer possible for gcc to act as a fork bomb when
- installed incorrectly.
- + The -fpack-struct option should be recognized now.
- + Fixed a bug that caused incorrect code to be generated due to
- a lost stack adjustment.
- * Platform specific bugfixes and improvements
- + Support building ARM toolchains hosted on Windows.
- + Fix attribute calculations in ARM toolchains.
- + arm-linux support has been improved.
- + Fix a PIC failure on sparc targets.
- + On ix86 targets, the regparm attribute should now work
- reliably.
- + Several updates for the h8300 port.
- + Fix problem building libio with glibc 2.2.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [17]GCC manuals. If that fails, the
- [18]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [19]gcc at gcc.gnu.org. All of [20]our lists have public
- archives.
-
- Copyright (C) [21]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [22]maintained by the GCC team. Last modified
- 2014-06-28[23].
-
-References
-
- 1. http://gcc.gnu.org/news/spill.html
- 2. http://gcc.gnu.org/news/lcm.html
- 3. http://gcc.gnu.org/news/cprop.html
- 4. http://gcc.gnu.org/news/cfg.html
- 5. http://gcc.gnu.org/news/dse.html
- 6. http://gcc.gnu.org/news/hoist.html
- 7. http://gcc.gnu.org/news/alias.html
- 8. http://gcc.gnu.org/gcc-2.95/c++features.html
- 9. https://gcc.gnu.org/onlinedocs/gcc-3.4.6/g77/News.html
- 10. http://gcc.gnu.org/java/gcj-announce.txt
- 11. http://gcc.gnu.org/news/javaannounce.html
- 12. http://gcc.gnu.org/c99status.html
- 13. http://gcc.gnu.org/news/chill.html
- 14. http://gcc.gnu.org/news/sparc.html
- 15. http://gcc.gnu.org/news/egcs-vcg.html
- 16. http://gcc.gnu.org/egcs-1.0/features-2.8.html
- 17. https://gcc.gnu.org/onlinedocs/
- 18. mailto:gcc-help at gcc.gnu.org
- 19. mailto:gcc at gcc.gnu.org
- 20. https://gcc.gnu.org/lists.html
- 21. http://www.fsf.org/
- 22. https://gcc.gnu.org/about.html
- 23. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/gcc-2.95/caveats.html
- GCC 2.95 Caveats
-
- * GCC 2.95 will issue an error for invalid asm statements that had
- been silently accepted by earlier versions of the compiler. This is
- particularly noticeable when compiling older versions of the Linux
- kernel (2.0.xx). Please refer to the FAQ (as shipped with GCC 2.95)
- for more information on this issue.
- * GCC 2.95 implements type based alias analysis to disambiguate
- memory references. Some programs, particularly the Linux kernel
- violate ANSI/ISO aliasing rules and therefore may not operate
- correctly when compiled with GCC 2.95. Please refer to the FAQ (as
- shipped with GCC 2.95) for more information on this issue.
- * GCC 2.95 has a known bug in its handling of complex variables for
- 64bit targets. Instead of silently generating incorrect code, GCC
- 2.95 will issue a fatal error for situations it can not handle.
- This primarily affects the Fortran community as Fortran makes more
- use of complex variables than C or C++.
- * GCC 2.95 has an integrated libstdc++, but does not have an
- integrated libg++. Furthermore old libg++ releases will not work
- with GCC 2.95. You can retrieve a recent copy of libg++ from the
- [1]GCC ftp server.
- Note most C++ programs only need libstdc++.
- * Exception handling may not work with shared libraries, particularly
- on alphas, hppas, rs6000/powerpc and mips based platforms.
- Exception handling is known to work on x86 GNU/Linux platforms with
- shared libraries.
- * In general, GCC 2.95 is more rigorous about rejecting invalid C++
- code or deprecated C++ constructs than G++ 2.7, G++ 2.8, EGCS 1.0,
- or EGCS 1.1. As a result it may be necessary to fix C++ code before
- it will compile with GCC 2.95.
- * G++ is also converting toward the ISO C++ standard; as a result
- code which was previously valid (and thus accepted by other
- compilers and older versions of g++) may no longer be accepted. The
- flag -fpermissive may allow some non-conforming code to compile
- with GCC 2.95.
- * GCC 2.95 compiled C++ code is not binary compatible with EGCS
- 1.1.x, EGCS 1.0.x or GCC 2.8.x.
- * GCC 2.95 does not have changes from the GCC 2.8 tree that were made
- between Sept 30, 1998 and April 30, 1999 (the official end of the
- GCC 2.8 project). Future GCC releases will include all the changes
- from the defunct GCC 2.8 sources.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [2]GCC manuals. If that fails, the
- [3]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [4]gcc at gcc.gnu.org. All of [5]our lists have public archives.
-
- Copyright (C) [6]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [7]maintained by the GCC team. Last modified
- 2014-06-12[8].
-
-References
-
- 1. ftp://gcc.gnu.org/pub/gcc/infrastructure/libg++-2.8.1.3.tar.gz
- 2. https://gcc.gnu.org/onlinedocs/
- 3. mailto:gcc-help at gcc.gnu.org
- 4. mailto:gcc at gcc.gnu.org
- 5. https://gcc.gnu.org/lists.html
- 6. http://www.fsf.org/
- 7. https://gcc.gnu.org/about.html
- 8. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/egcs-1.1/index.html
- EGCS 1.1
-
- September 3, 1998: We are pleased to announce the release of EGCS 1.1.
- December 1, 1998: We are pleased to announce the release of EGCS 1.1.1.
- March 15, 1999: We are pleased to announce the release of EGCS 1.1.2.
-
- EGCS is a free software project to further the development of the GNU
- compilers using an open development environment.
-
- EGCS 1.1 is a major new release of the EGCS compiler system. It has
- been [1]extensively tested and is believed to be stable and suitable
- for widespread use.
-
- EGCS 1.1 is based on an June 6, 1998 snapshot of the GCC 2.8
- development sources; it contains all of the new features found in GCC
- 2.8.1 as well as all new development from GCC up to June 6, 1998.
-
- EGCS 1.1 also contains many improvements and features not found in GCC
- or in older versions of EGCS:
- * Global common subexpression elimination and global constant/copy
- propagation (aka [2]gcse)
- * Ongoing improvements to the [3]alias analysis support to allow for
- better optimizations throughout the compiler.
- * Vastly improved [4]C++ compiler and integrated C++ runtime
- libraries.
- * Fixes for the /tmp symlink race security problems.
- * New targets including mips16, arm-thumb and 64 bit PowerPC.
- * Improvements to GNU Fortran (g77) compiler and runtime library made
- since g77 version 0.5.23.
-
- See the [5]new features page for a more complete list of new features
- found in EGCS 1.1 releases.
-
- EGCS 1.1.1 is a minor update to fix several serious problems in EGCS
- 1.1:
- * General improvements and fixes
- + Avoid some stack overflows when compiling large functions.
- + Avoid incorrect loop invariant code motions.
- + Fix some core dumps on Linux kernel code.
- + Bring back the imake -Di386 and friends fix from EGCS 1.0.2.
- + Fix code generation problem in gcse.
- + Various documentation related fixes.
- * g++/libstdc++ improvements and fixes
- + MT safe EH fix for setjmp/longjmp based exception handling.
- + Fix a few bad interactions between optimization and exception
- handling.
- + Fixes for demangling of template names starting with "__".
- + Fix a bug that would fail to run destructors in some cases
- with -O2.
- + Fix 'new' of classes with virtual bases.
- + Fix crash building Qt on the Alpha.
- + Fix failure compiling WIFEXITED macro on GNU/Linux.
- + Fix some -frepo failures.
- * g77 and libf2c improvements and fixes
- + Various documentation fixes.
- + Avoid compiler crash on RAND intrinsic.
- + Fix minor bugs in makefiles exposed by BSD make programs.
- + Define _XOPEN_SOURCE for libI77 build to avoid potential
- problems on some 64-bit systems.
- + Fix problem with implicit endfile on rewind.
- + Fix spurious recursive I/O errors.
- * platform specific improvements and fixes
- + Match all versions of UnixWare7.
- + Do not assume x86 SVR4 or UnixWare targets can handle stabs.
- + Fix PPC/RS6000 LEGITIMIZE_ADDRESS macro and bug in conversion
- from unsigned ints to double precision floats.
- + Fix ARM ABI issue with NetBSD.
- + Fix a few arm code generation bugs.
- + Fixincludes will fix additional broken SCO OpenServer header
- files.
- + Fix a m68k backend bug which caused invalid offsets in reg+d
- addresses.
- + Fix problems with 64bit AIX 4.3 support.
- + Fix handling of long longs for varargs/stdarg functions on the
- ppc.
- + Minor fixes to CPP predefines for Windows.
- + Fix code generation problems with gpr<->fpr copies for 64bit
- ppc.
- + Fix a few coldfire code generation bugs.
- + Fix some more header file problems on SunOS 4.x.
- + Fix assert.h handling for RTEMS.
- + Fix Windows handling of TREE_SYMBOL_REFERENCED.
- + Fix x86 compiler abort in reg-stack pass.
- + Fix cygwin/windows problem with section attributes.
- + Fix Alpha code generation problem exposed by SMP Linux
- kernels.
- + Fix typo in m68k 32->64bit integer conversion.
- + Make sure target libraries build with -fPIC for PPC & Alpha
- targets.
-
- EGCS 1.1.2 is a minor update to fix several serious problems in EGCS
- 1.1.1:
- * General improvements and fixes
- + Fix bug in loop optimizer which caused the SPARC (and
- potentially other) ports to segfault.
- + Fix infinite recursion in alias analysis and combiner code.
- + Fix bug in regclass preferencing.
- + Fix incorrect loop reversal which caused incorrect code to be
- generated for several targets.
- + Fix return value for builtin memcpy.
- + Reduce compile time for certain loops which exposed quadratic
- behavior in the loop optimizer.
- + Fix bug which caused volatile memory to be written multiple
- times when only one write was needed/desired.
- + Fix compiler abort in caller-save.c
- + Fix combiner bug which caused incorrect code generation for
- certain division by constant operations.
- + Fix incorrect code generation due to a bug in range check
- optimizations.
- + Fix incorrect code generation due to mis-handling of clobbered
- values in CSE.
- + Fix compiler abort/segfault due to incorrect register
- splitting when unrolling loops.
- + Fix code generation involving autoincremented addresses with
- ternary operators.
- + Work around bug in the scheduler which caused qt to be
- mis-compiled on some platforms.
- + Fix code generation problems with -fshort-enums.
- + Tighten security for temporary files.
- + Improve compile time for codes which make heavy use of
- overloaded functions.
- + Fix multiply defined constructor/destructor symbol problems.
- + Avoid setting bogus RPATH environment variable during
- bootstrap.
- + Avoid GNU-make dependencies in the texinfo subdir.
- + Install CPP wrapper script in $(prefix)/bin if --enable-cpp.
- --enable-cpp=<dirname> can be used to specify an additional
- install directory for the cpp wrapper script.
- + Fix CSE bug which caused incorrect label-label refs to appear
- on some platforms.
- + Avoid linking in EH routines from libgcc if they are not
- needed.
- + Avoid obscure bug in aliasing code.
- + Fix bug in weak symbol handling.
- * Platform-specific improvements and fixes
- + Fix detection of PPro/PII on Unixware 7.
- + Fix compiler segfault when building spec99 and other programs
- for SPARC targets.
- + Fix code-generation bugs for integer and floating point
- conditional move instructions on the PPro/PII.
- + Use fixincludes to fix byteorder problems on i?86-*-sysv.
- + Fix build failure for the arc port.
- + Fix floating point format configuration for i?86-gnu port.
- + Fix problems with hppa1.0-hp-hpux10.20 configuration when
- threads are enabled.
- + Fix coldfire code generation bugs.
- + Fix "unrecognized insn" problems for Alpha and PPC ports.
- + Fix h8/300 code generation problem with floating point values
- in memory.
- + Fix unrecognized insn problems for the m68k port.
- + Fix namespace-pollution problem for the x86 port.
- + Fix problems with old assembler on x86 NeXT systems.
- + Fix PIC code-generation problems for the SPARC port.
- + Fix minor bug with LONG_CALLS in PowerPC SVR4 support.
- + Fix minor ISO namespace violation in Alpha varargs/stdarg
- support.
- + Fix incorrect "braf" instruction usage for the SH port.
- + Fix minor bug in va-sh which prevented its use with -ansi.
- + Fix problems recognizing and supporting FreeBSD.
- + Handle OpenBSD systems correctly.
- + Minor fixincludes fix for Digital UNIX 4.0B.
- + Fix problems with ctors/dtors in SCO shared libraries.
- + Abort instead of generating incorrect code for PPro/PII
- floating point conditional moves.
- + Avoid multiply defined symbols on GNU/Linux systems using
- libc-5.4.xx.
- + Fix abort in alpha compiler.
- * Fortran-specific fixes
- + Fix the IDate intrinsic (VXT) (in libg2c) so the returned year
- is in the documented, non-Y2K-compliant range of 0-99, instead
- of being returned as 100 in the year 2000.
- + Fix the `Date_and_Time' intrinsic (in libg2c) to return the
- milliseconds value properly in Values(8).
- + Fix the `LStat' intrinsic (in libg2c) to return device-ID
- information properly in SArray(7).
-
- Each release includes installation instructions in both HTML and
- plaintext forms (see the INSTALL directory in the toplevel directory of
- the distribution). However, we also keep the most up to date
- installation instructions and [6]build/test status on our web page. We
- will update those pages as new information becomes available.
-
- The EGCS project would like to thank the numerous people that have
- contributed new features, test results, bugfixes, etc. This [7]amazing
- group of volunteers is what makes EGCS successful.
-
- And finally, we can't in good conscience fail to mention some
- [8]caveats to using EGCS 1.1.
-
- Download EGCS from egcs.cygnus.com (USA California).
-
- The EGCS 1.1 release is also available on many mirror sites.
- [9]Goto mirror list to find a closer site.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [10]GCC manuals. If that fails, the
- [11]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [12]gcc at gcc.gnu.org. All of [13]our lists have public
- archives.
-
- Copyright (C) [14]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [15]maintained by the GCC team. Last modified
- 2014-06-28[16].
-
-References
-
- 1. http://gcc.gnu.org/egcs-1.1/egcs-1.1-test.html
- 2. http://gcc.gnu.org/news/gcse.html
- 3. http://gcc.gnu.org/news/alias.html
- 4. http://gcc.gnu.org/egcs-1.1/c++features.html
- 5. http://gcc.gnu.org/egcs-1.1/features.html
- 6. http://gcc.gnu.org/egcs-1.1/buildstat.html
- 7. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html
- 8. http://gcc.gnu.org/egcs-1.1/caveats.html
- 9. http://gcc.gnu.org/mirrors.html
- 10. https://gcc.gnu.org/onlinedocs/
- 11. mailto:gcc-help at gcc.gnu.org
- 12. mailto:gcc at gcc.gnu.org
- 13. https://gcc.gnu.org/lists.html
- 14. http://www.fsf.org/
- 15. https://gcc.gnu.org/about.html
- 16. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/egcs-1.1/features.html
- EGCS 1.1 new features
-
- * Integrated GNU Fortran (g77) compiler and runtime library with
- improvements, based on g77 version 0.5.23.
- * Vast improvements in the C++ compiler; so many they have [1]page of
- their own!
- * Compiler implements [2]global common subexpression elimination and
- global copy/constant propagation.
- * More major improvements in the [3]alias analysis code.
- * More major improvements in the exception handling code to improve
- performance, lower static overhead and provide the infrastructure
- for future improvements.
- * The infamous /tmp symlink race security problems have been fixed.
- * The regmove optimization pass has been nearly completely rewritten
- to improve performance of generated code.
- * The compiler now recomputes register usage information before local
- register allocation. By providing more accurate information to the
- priority based allocator, we get better register allocation.
- * The register reloading phase of the compiler optimizes spill code
- much better than in previous releases.
- * Some bad interactions between the register allocator and
- instruction scheduler have been fixed, resulting in much better
- code for certain programs. Additionally, we have tuned the
- scheduler in various ways to improve performance of generated code
- for some architectures.
- * The compiler's branch shortening algorithms have been significantly
- improved to work better on targets which align jump targets.
- * The compiler now supports -Os to prefer optimizing for code space
- over optimizing for code speed.
- * The compiler will now totally eliminate library calls which compute
- constant values. This primarily helps targets with no integer
- div/mul support and targets without floating point support.
- * The compiler now supports an extensive "--help" option.
- * cpplib has been greatly improved and may be suitable for limited
- use.
- * Memory footprint for the compiler has been significantly reduced
- for some pathological cases.
- * The time to build EGCS has been improved for certain targets
- (particularly the alpha and mips platforms).
- * Many infrastructure improvements throughout the compiler, plus the
- usual mountain of bugfixes and minor improvements.
- * Target dependent improvements:
- + SPARC port now includes V8 plus and V9 support as well as
- performance tuning for Ultra class machines. The SPARC port
- now uses the Haifa scheduler.
- + Alpha port has been tuned for the EV6 processor and has an
- optimized expansion of memcpy/bzero. The Alpha port now uses
- the Haifa scheduler.
- + RS6000/PowerPC: support for the Power64 architecture and AIX
- 4.3. The RS6000/PowerPC port now uses the Haifa scheduler.
- + x86: Alignment of static store data and jump targets is per
- Intel recommendations now. Various improvements throughout the
- x86 port to improve performance on Pentium processors
- (including improved epilogue sequences for Pentium chips and
- backend improvements which should help register allocation on
- all x86 variants. Conditional move support has been fixed and
- enabled for PPro processors. The x86 port also better supports
- 64bit operations now. Unixware 7, a System V Release 5 target,
- is now supported and SCO OpenServer targets can support GAS.
- + MIPS has improved multiply/multiply-add support and now
- includes mips16 ISA support.
- + M68k has many micro-optimizations and Coldfire fixes.
- * Core compiler is based on the GCC development tree from June 9,
- 1998, so we have all of the [4]features found in GCC 2.8.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [5]GCC manuals. If that fails, the
- [6]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [7]gcc at gcc.gnu.org. All of [8]our lists have public archives.
-
- Copyright (C) [9]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [10]maintained by the GCC team. Last modified
- 2014-06-12[11].
-
-References
-
- 1. http://gcc.gnu.org/egcs-1.1/c++features.html
- 2. http://gcc.gnu.org/news/gcse.html
- 3. http://gcc.gnu.org/news/alias.html
- 4. http://gcc.gnu.org/egcs-1.0/features-2.8.html
- 5. https://gcc.gnu.org/onlinedocs/
- 6. mailto:gcc-help at gcc.gnu.org
- 7. mailto:gcc at gcc.gnu.org
- 8. https://gcc.gnu.org/lists.html
- 9. http://www.fsf.org/
- 10. https://gcc.gnu.org/about.html
- 11. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/egcs-1.1/caveats.html
- EGCS 1.1 Caveats
-
- * EGCS has an integrated libstdc++, but does not have an integrated
- libg++. Furthermore old libg++ releases will not work with EGCS; HJ
- Lu has made a libg++-2.8.1.2 snapshot available which may work with
- EGCS.
- Note most C++ programs only need libstdc++.
- * Exception handling may not work with shared libraries, particularly
- on alphas, hppas, rs6000/powerpc and mips based platforms.
- Exception handling is known to work on x86-linux platforms with
- shared libraries.
- * Some versions of the Linux kernel have bugs which prevent them from
- being compiled or from running when compiled by EGCS. See the FAQ
- (as shipped with EGCS 1.1) for additional information.
- * In general, EGCS is more rigorous about rejecting invalid C++ code
- or deprecated C++ constructs than g++-2.7, g++-2.8 or EGCS 1.0. As
- a result it may be necessary to fix C++ code before it will compile
- with EGCS.
- * G++ is also converting toward the ISO C++ standard; as a result
- code which was previously valid (and thus accepted by other
- compilers and older versions of g++) may no longer be accepted.
- * EGCS 1.1 compiled C++ code is not binary compatible with EGCS 1.0.x
- or GCC 2.8.x due to changes necessary to support thread safe
- exception handling.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [1]GCC manuals. If that fails, the
- [2]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [3]gcc at gcc.gnu.org. All of [4]our lists have public archives.
-
- Copyright (C) [5]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [6]maintained by the GCC team. Last modified
- 2014-06-12[7].
-
-References
-
- 1. https://gcc.gnu.org/onlinedocs/
- 2. mailto:gcc-help at gcc.gnu.org
- 3. mailto:gcc at gcc.gnu.org
- 4. https://gcc.gnu.org/lists.html
- 5. http://www.fsf.org/
- 6. https://gcc.gnu.org/about.html
- 7. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/egcs-1.0/index.html
- EGCS 1.0
-
- December 3, 1997: We are pleased to announce the release of EGCS 1.0.
- January 6, 1998: We are pleased to announce the release of EGCS 1.0.1.
- March 16, 1998: We are pleased to announce the release of EGCS 1.0.2.
- May 15, 1998 We are pleased to announce the release of EGCS 1.0.3.
-
- EGCS is a collaborative effort involving several groups of hackers
- using an open development model to accelerate development and testing
- of GNU compilers and runtime libraries.
-
- An important goal of EGCS is to allow wide scale testing of
- experimental features and optimizations; therefore, EGCS contains some
- features and optimizations which are still under development. However,
- EGCS has been carefully tested and should be comparable in quality to
- most GCC releases.
-
- EGCS 1.0 is based on an August 2, 1997 snapshot of the GCC 2.8
- development sources; it contains nearly all of the new features found
- in GCC 2.8.
-
- EGCS 1.0 also contains many improvements and features not found in GCC
- 2.7 and even the GCC 2.8 series (which was released after the original
- EGCS 1.0 release).
- * Integrated C++ runtime libraries, including support for most major
- GNU/Linux systems!
- * The integrated libstdc++ library includes a verbatim copy of SGI's
- STL release.
- * Integrated GNU Fortran compiler.
- * New instruction scheduler.
- * New alias analysis code.
-
- See the [1]new features page for a more complete list of new features.
-
- EGCS 1.0.1 is a minor update to the EGCS 1.0 compiler to fix a few
- critical bugs and add support for Red Hat 5.0 Linux. Changes since the
- EGCS 1.0 release:
- * Add support for Red Hat 5.0 Linux and better support for Linux
- systems using glibc2.
- Many programs failed to link when compiled with EGCS 1.0 on Red Hat
- 5.0 or on systems with newer versions of glibc2. EGCS 1.0.1 should
- fix these problems.
- * Compatibility with both EGCS 1.0 and GCC 2.8 libgcc exception
- handling interfaces.
- To avoid future compatibility problems, we strongly urge anyone who
- is planning on distributing shared libraries that contain C++ code
- to upgrade to EGCS 1.0.1 first.
- Soon after EGCS 1.0 was released, the GCC developers made some
- incompatible changes in libgcc's exception handling interfaces.
- These changes were needed to solve problems on some platforms. This
- means that GCC 2.8.0, when released, will not be seamlessly
- compatible with shared libraries built by EGCS 1.0. The reason is
- that the libgcc.a in GCC 2.8.0 will not contain a function needed
- by the old interface.
- The result of this is that there may be compatibility problems with
- shared libraries built by EGCS 1.0 when used with GCC 2.8.0.
- With EGCS 1.0.1, generated code uses the new (GCC 2.8.0) interface,
- and libgcc.a has the support routines for both the old and the new
- interfaces (so EGCS 1.0.1 and EGCS 1.0 code can be freely mixed,
- and EGCS 1.0.1 and GCC 2.8.0 code can be freely mixed).
- The maintainers of GCC 2.x have decided against including seamless
- support for the old interface in 2.8.0, since it was never
- "official", so to avoid future compatibility problems we recommend
- against distributing any shared libraries built by EGCS 1.0 that
- contain C++ code (upgrade to 1.0.1 and use that).
- * Various bugfixes in the x86, hppa, mips, and rs6000/ppc back ends.
- The x86 changes fix code generation errors exposed when building
- glibc2 and the usual GNU/Linux dynamic linker (ld.so).
- The hppa change fixes a compiler abort when configured for use with
- RTEMS.
- The MIPS changes fix problems with the definition of LONG_MAX on
- newer systems, allow for command line selection of the target ABI,
- and fix one code generation problem.
- The rs6000/ppc change fixes some problems with passing structures
- to varargs/stdarg functions.
- * A few machine independent bugfixes, mostly to fix code generation
- errors when building Linux kernels or glibc.
- * Fix a few critical exception handling and template bugs in the C++
- compiler.
- * Fix Fortran namelist bug on alphas.
- * Fix build problems on x86-solaris systems.
-
- EGCS 1.0.2 is a minor update to the EGCS 1.0.1 compiler to fix several
- serious problems in EGCS 1.0.1.
- * General improvements and fixes
- + Memory consumption significantly reduced, especially for
- templates and inline functions.
- + Fix various problems with glibc2.1.
- + Fix loop optimization bug exposed by rs6000/ppc port.
- + Fix to avoid potential code generation problems in jump.c.
- + Fix some undefined symbol problems in dwarf1 debug support.
- * g++/libstdc++ improvements and fixes
- + libstdc++ in the EGCS release has been updated and should be
- link compatible with libstdc++-2.8.
- + Various fixes in libio/libstdc++ to work better on GNU/Linux
- systems.
- + Fix problems with duplicate symbols on systems that do not
- support weak symbols.
- + Memory corruption bug and undefined symbols in bastring have
- been fixed.
- + Various exception handling fixes.
- + Fix compiler abort for very long thunk names.
- * g77 improvements and fixes
- + Fix compiler crash for omitted bound in Fortran CASE
- statement.
- + Add missing entries to g77 lang-options.
- + Fix problem with -fpedantic in the g77 compiler.
- + Fix "backspace" problem with g77 on alphas.
- + Fix x86 backend problem with Fortran literals and -fpic.
- + Fix some of the problems with negative subscripts for g77 on
- alphas.
- + Fixes for Fortran builds on cygwin32/mingw32.
- * platform specific improvements and fixes
- + Fix long double problems on x86 (exposed by glibc).
- + x86 ports define i386 again to keep imake happy.
- + Fix exception handling support on NetBSD ports.
- + Several changes to collect2 to fix many problems with AIX.
- + Define __ELF__ for GNU/Linux on rs6000.
- + Fix -mcall-linux problem on GNU/Linux on rs6000.
- + Fix stdarg/vararg problem for GNU/Linux on rs6000.
- + Allow autoconf to select a proper install problem on AIX 3.1.
- + m68k port support includes -mcpu32 option as well as cpu32
- multilibs.
- + Fix stdarg bug for irix6.
- + Allow EGCS to build on irix5 without the gnu assembler.
- + Fix problem with static linking on sco5.
- + Fix bootstrap on sco5 with native compiler.
- + Fix for abort building newlib on H8 target.
- + Fix fixincludes handling of math.h on SunOS.
- + Minor fix for Motorola 3300 m68k systems.
-
- EGCS 1.0.3 is a minor update to the EGCS 1.0.2 compiler to fix a few
- problems reported by Red Hat for builds of Red Hat 5.1.
- * Generic bugfixes:
- + Fix a typo in the libio library which resulted in incorrect
- behavior of istream::get.
- + Fix the Fortran negative array index problem.
- + Fix a major problem with the ObjC runtime thread support
- exposed by glibc2.
- + Reduce memory consumption of the Haifa scheduler.
- * Target specific bugfixes:
- + Fix one x86 floating point code generation bug exposed by
- glibc2 builds.
- + Fix one x86 internal compiler error exposed by glibc2 builds.
- + Fix profiling bugs on the Alpha.
- + Fix ImageMagick & emacs 20.2 build problems on the Alpha.
- + Fix rs6000/ppc bug when converting values from integer types
- to floating point types.
-
- The EGCS 1.0 releases include installation instructions in both HTML
- and plaintext forms (see the INSTALL directory in the toplevel
- directory of the distribution). However, we also keep the most up to
- date installation instructions and [2]build/test status on our web
- page. We will update those pages as new information becomes available.
-
- And, we can't in good conscience fail to mention some [3]caveats to
- using EGCS.
-
- Update: Big thanks to Stanford for providing a high speed link for
- downloading EGCS (go.cygnus.com)!
-
- Download EGCS from ftp.cygnus.com (USA California) or go.cygnus.com
- (USA California -- High speed link provided by Stanford).
-
- The EGCS 1.0 release is also available many mirror sites.
- [4]Goto mirror list to find a closer site
-
- We'd like to thank the numerous people that have contributed new
- features, test results, bugfixes, etc. Unfortunately, they're far too
- numerous to mention by name.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [5]GCC manuals. If that fails, the
- [6]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [7]gcc at gcc.gnu.org. All of [8]our lists have public archives.
-
- Copyright (C) [9]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [10]maintained by the GCC team. Last modified
- 2014-06-28[11].
-
-References
-
- 1. http://gcc.gnu.org/egcs-1.0/features.html
- 2. http://gcc.gnu.org/egcs-1.0/buildstat.html
- 3. http://gcc.gnu.org/egcs-1.0/caveats.html
- 4. http://gcc.gnu.org/mirrors.html
- 5. https://gcc.gnu.org/onlinedocs/
- 6. mailto:gcc-help at gcc.gnu.org
- 7. mailto:gcc at gcc.gnu.org
- 8. https://gcc.gnu.org/lists.html
- 9. http://www.fsf.org/
- 10. https://gcc.gnu.org/about.html
- 11. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/egcs-1.0/features.html
- EGCS 1.0 features
-
- * Core compiler is based on the gcc2 development tree from Aug 2,
- 1997, so we have most of the [1]features found in GCC 2.8.
- * Integrated GNU Fortran compiler based on g77-0.5.22-19970929.
- * Vast improvements in the C++ compiler; so many they have [2]page of
- their own!
- * Integrated C++ runtime libraries, including support for most major
- GNU/Linux systems!
- * New instruction scheduler from IBM Haifa which includes support for
- function wide instruction scheduling as well as superscalar
- scheduling.
- * Significantly improved alias analysis code.
- * Improved register allocation for two address machines.
- * Significant code generation improvements for Fortran code on
- Alphas.
- * Various optimizations from the g77 project as well as improved loop
- optimizations.
- * Dwarf2 debug format support for some targets.
- * egcs libstdc++ includes the SGI STL implementation without changes.
- * As a result of these and other changes, egcs libstc++ is not binary
- compatible with previous releases of libstdc++.
- * Various new ports -- UltraSPARC, Irix6.2 & Irix6.3 support, The SCO
- Openserver 5 family (5.0.{0,2,4} and Internet FastStart 1.0 and
- 1.1), Support for RTEMS on several embedded targets, Support for
- arm-linux, Mitsubishi M32R, Hitachi H8/S, Matsushita MN102 and
- MN103, NEC V850, Sparclet, Solaris & GNU/Linux on PowerPCs, etc.
- * Integrated testsuites for gcc, g++, g77, libstdc++ and libio.
- * RS6000/PowerPC ports generate code which can run on all
- RS6000/PowerPC variants by default.
- * -mcpu= and -march= switches for the x86 port to allow better
- control over how the x86 port generates code.
- * Includes the template repository patch (aka repo patch); note the
- new template code makes repo obsolete for ELF systems using gnu-ld
- such as GNU/Linux.
- * Plus the usual assortment of bugfixes and improvements.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [3]GCC manuals. If that fails, the
- [4]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [5]gcc at gcc.gnu.org. All of [6]our lists have public archives.
-
- Copyright (C) [7]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [8]maintained by the GCC team. Last modified
- 2014-06-12[9].
-
-References
-
- 1. http://gcc.gnu.org/egcs-1.0/features-2.8.html
- 2. http://gcc.gnu.org/egcs-1.0/c++features.html
- 3. https://gcc.gnu.org/onlinedocs/
- 4. mailto:gcc-help at gcc.gnu.org
- 5. mailto:gcc at gcc.gnu.org
- 6. https://gcc.gnu.org/lists.html
- 7. http://www.fsf.org/
- 8. https://gcc.gnu.org/about.html
- 9. http://validator.w3.org/check/referer
-======================================================================
-http://gcc.gnu.org/egcs-1.0/caveats.html
- EGCS 1.0 Caveats
-
- * EGCS has an integrated libstdc++, but does not have an integrated
- libg++. Furthermore old libg++ releases will not work with egc; HJ
- Lu has made a libg++-2.8.1.2 available which may work with EGCS.
- Note most C++ programs only need libstdc++.
- * Note that using -pedantic or -Wreturn-type can cause an explosion
- in the amount of memory needed for template-heavy C++ code, such as
- code that uses STL. Also note that -Wall includes -Wreturn-type, so
- if you use -Wall you will need to specify -Wno-return-type to turn
- it off.
- * Exception handling may not work with shared libraries, particularly
- on alphas, hppas, and mips based platforms. Exception handling is
- known to work on x86-linux platforms with shared libraries.
- * Some versions of the Linux kernel have bugs which prevent them from
- being compiled or from running when compiled by EGCS. See the FAQ
- (as shipped with EGCS 1.0) for additional information.
- * In general, EGCS is more rigorous about rejecting invalid C++ code
- or deprecated C++ constructs than G++ 2.7. As a result it may be
- necessary to fix C++ code before it will compile with EGCS.
- * G++ is also aggressively tracking the C++ standard; as a result
- code which was previously valid (and thus accepted by other
- compilers and older versions of G++) may no longer be accepted.
- * EGCS 1.0 may not work with Red Hat Linux 5.0 on all targets. EGCS
- 1.0.x and later releases should work with Red Hat Linux 5.0.
-
-
- For questions related to the use of GCC, please consult these web
- pages and the [1]GCC manuals. If that fails, the
- [2]gcc-help at gcc.gnu.org mailing list might help. Comments on these
- web pages and the development of GCC are welcome on our developer
- list at [3]gcc at gcc.gnu.org. All of [4]our lists have public archives.
-
- Copyright (C) [5]Free Software Foundation, Inc. Verbatim copying and
- distribution of this entire article is permitted in any medium,
- provided this notice is preserved.
-
- These pages are [6]maintained by the GCC team. Last modified
- 2014-06-12[7].
-
-References
-
- 1. https://gcc.gnu.org/onlinedocs/
- 2. mailto:gcc-help at gcc.gnu.org
- 3. mailto:gcc at gcc.gnu.org
- 4. https://gcc.gnu.org/lists.html
- 5. http://www.fsf.org/
- 6. https://gcc.gnu.org/about.html
- 7. http://validator.w3.org/check/referer
-======================================================================
+ 1. http://gcc.gnu.org/gcc-6/porting_to.html
+ 2. http://gcc.gnu.org/onlinedocs/index.html#current
+ 3. https://gcc.gnu.org/ml/gcc/2015-08/msg00101.html
+ 4. http://www.openacc.org/
+ 5. https://gcc.gnu.org/wiki/OpenACC
+ 6. https://gcc.gnu.org/wiki/Offloading
+ 7. http://openmp.org/wp/openmp-specifications/
+ 8. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-1266
+ 9. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4377.pdf
+ 10. https://gcc.gnu.org/projects/cxx-status.html#cxx1z.html
+ 11. https://gcc.gnu.org/onlinedocs/jit/topics/performance.html
+ 12. https://gcc.gnu.org/onlinedocs/jit/topics/functions.html#gcc_jit_block_end_with_switch
+ 13. https://gcc.gnu.org/onlinedocs/jit/topics/contexts.html#gcc_jit_context_set_bool_allow_unreachable_blocks
+ 14. https://gcc.gnu.org/onlinedocs/jit/topics/contexts.html#gcc_jit_context_add_command_line_option
+ 15. https://gcc.gnu.org/onlinedocs/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes
+ 16. https://gcc.gnu.org/onlinedocs/gcc/ARM-Function-Attributes.html#ARM-Function-Attributes
+ 17. https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html#Named-Address-Spaces
+ 18. https://gcc.gnu.org/onlinedocs/gcc/S_002f390-Function-Attributes.html#S_002f390-Function-Attributes
+ 19. http://www.musl-libc.org/
+ 20. https://gcc.gnu.org/onlinedocs/
+ 21. mailto:gcc-help at gcc.gnu.org
+ 22. mailto:gcc at gcc.gnu.org
+ 23. https://gcc.gnu.org/lists.html
+ 24. http://www.fsf.org/
+ 25. https://gcc.gnu.org/about.html
+ 26. http://validator.w3.org/check/referer
diff --git a/debian/NEWS.html b/debian/NEWS.html
index 43981ed..6519297 100644
--- a/debian/NEWS.html
+++ b/debian/NEWS.html
@@ -26,7 +26,7 @@
<link rel="stylesheet" type="text/css" href="https://gcc.gnu.org/gcc.css" />
<title>
-GCC 5 Release Series — Changes, New Features, and Fixes
+GCC 6 Release Series — Changes, New Features, and Fixes
- GNU Project - Free Software Foundation (FSF)</title>
</head>
@@ -39,908 +39,780 @@ GCC 5 Release Series — Changes, New Features, and Fixes
-<h1>GCC 5 Release Series<br />Changes, New Features, and Fixes</h1>
+<h1>GCC 6 Release Series<br />Changes, New Features, and Fixes</h1>
+<p>
+This page is a brief summary of some of the huge number of improvements in GCC 6.
+For more information, see the
+<a href="porting_to.html">Porting to GCC 6</a> page and the
+<a href="../onlinedocs/index.html#current">full GCC documentation</a>.
+</p>
+<!-- .................................................................. -->
<h2>Caveats</h2>
<ul>
- <li>The default mode for C is now <code>-std=gnu11</code> instead of
- <code>-std=gnu89</code>.</li>
- <li>The C++ runtime library (libstdc++) uses a new ABI by default
- (see <a href="#libstdcxx">below</a>).</li>
- <li>The Graphite framework for loop optimizations no longer requires the
- CLooG library, only ISL version 0.14 (recommended) or 0.12.2. The
- installation manual contains more information about requirements to
- build GCC.</li>
- <li>The non-standard C++0x type traits
- <code>has_trivial_default_constructor</code>,
- <code>has_trivial_copy_constructor</code> and
- <code>has_trivial_copy_assign</code> have been deprecated and will
- be removed in a future version. The standard C++11 traits
- <code>is_trivially_default_constructible</code>,
- <code>is_trivially_copy_constructible</code> and
- <code>is_trivially_copy_assignable</code> should be used instead.</li>
+ <li>The default mode for C++ is now <code>-std=gnu++14</code> instead of
+ <code>-std=gnu++98</code>.</li>
+
+ <li><p>Support for a number of older systems and recently
+ unmaintained or untested target ports of GCC has been declared
+ obsolete in GCC 6. Unless there is activity to revive them, the
+ next release of GCC will have their sources permanently
+ <strong>removed</strong>.</p>
+
+ <p>The following ports for individual systems on
+ particular architectures have been obsoleted:</p>
+
+ <ul>
+ <li>SH5 / SH64 (sh64-*-*) as announced
+ <a href="https://gcc.gnu.org/ml/gcc/2015-08/msg00101.html">
+ here</a>.</li>
+ </ul>
+ </li>
+
</ul>
+<!-- .................................................................. -->
<h2 id="general">General Optimizer Improvements</h2>
-
<ul>
- <li>Inter-procedural optimization improvements:
- <ul>
- <li>An Identical Code Folding (ICF) pass (controlled via
- <code>-fipa-icf</code>) has been added. Compared to the identical
- code folding performed by the Gold linker this
- pass does not require function sections. It also performs merging
- before inlining, so inter-procedural optimizations are aware of the
- code re-use. On the other hand not all unifications performed
- by a linker are doable by GCC which must honor
- aliasing information. During link-time optimization of Firefox,
- this pass unifies about 31000 functions, that is 14% overall.</li>
- <li>The devirtualization pass was significantly improved by adding
- better support for speculative devirtualization and dynamic type
- detection. About 50% of virtual calls in Firefox are now
- speculatively devirtualized during link-time optimization.</li>
- <li>A new comdat localization pass allows the linker to eliminate more
- dead code in presence of C++ inline functions.</li>
- <li>Virtual tables are now optimized. Local aliases are used to reduce
- dynamic linking time of C++ virtual tables on ELF targets and
- data alignment has been reduced to limit data segment bloat.</li>
- <li>A new <code>-fno-semantic-interposition</code> option can be used
- to improve code quality of shared libraries where interposition of
- exported symbols is not allowed.</li>
- <li>Write-only variables are now detected and optimized out.</li>
- <li>With profile feedback the function inliner can now bypass
- <code>--param inline-insns-auto</code> and <code>--param
- inline-insns-single</code> limits for hot calls.</li>
- <li>The IPA reference pass was significantly sped up making it feasible
- to enable <code>-fipa-reference</code> with
- <code>-fprofile-generate</code>. This also solves a bottleneck
- seen when building Chromium with link-time optimization.</li>
- <li>The symbol table and call-graph API was reworked to C++ and
- simplified.</li>
- <li>The interprocedural propagation of constants now also propagates
- alignments of pointer parameters. This for example means that the
- vectorizer often does not need to generate loop prologues and epilogues
- to make up for potential misalignments.</li>
- </ul></li>
+ <li>UndefinedBehaviorSanitizer gained a new sanitization option,
+ <code>-fsanitize=bounds-strict</code>, which enables strict checking
+ of array bounds. In particular, it enables
+ <code>-fsanitize=bounds</code> as well as instrumentation of
+ flexible array member-like arrays.</li>
+ <li>Type-based alias analysis now disambiguates accesses to different
+ pointers. This improves precision of the alias oracle by about 20-30%
+ on higher-level C++ programs. Programs doing invalid type punning
+ of pointer types may now need <code>-fno-strict-aliasing</code>
+ to work correctly.</li>
+ <li>Alias analysis now correctly supports <code>weakref</code> and
+ <code>alias</code> attributes. This makes it possible to access
+ both a variable and its alias in one translation unit which is common
+ with link-time optimization.</li>
+ <li>Value range propagation now assumes that the <code>this</code> pointer
+ of C++ member functions is non-null. This eliminates
+ common null pointer checks
+ but also breaks some non-conforming code-bases (such as Qt-5, Chromium,
+ KDevelop). As a temporary work-around
+ <code>-fno-delete-null-pointer-checks</code> can be used. Wrong
+ code can be identified by using <code>-fsanitize=undefined</code>.</li>
<li>Link-time optimization improvements:
<ul>
- <li>One Definition Rule based merging of C++ types has been implemented.
- Type merging enables better devirtualization and alias analysis.
- Streaming extra information needed to merge types adds about 2-6% of
- memory size and object size increase. This can be controlled by
- <code>-flto-odr-type-merging</code>.</li>
- <li><p>Command-line optimization and target options are now streamed on
- a per-function basis and honored by the link-time optimizer.
- This change makes link-time optimization a more transparent
- replacement of per-file optimizations.
- It is now possible to build projects that require
- different optimization
- settings for different translation units (such as
- <code>-ffast-math</code>, <code>-mavx</code>, or
- <code>-finline</code>).
- Contrary to earlier GCC releases, the optimization and target
- options passed on the link command line are ignored.</p>
- <p>Note that this applies only to those command-line options
- that can be passed to <code>optimize</code> and
- <code>target</code> attributes.
- Command-line options affecting global code generation
- (such as <code>-fpic</code>), warnings
- (such as <code>-Wodr</code>),
- optimizations affecting the way static variables
- are optimized (such as <code>-fcommon</code>), debug output (such as
- <code>-g</code>),
- and <code>--param</code> parameters can be applied only
- to the whole link-time optimization unit.
- In these cases, it is recommended to consistently use the same
- options at both compile time and link time.</p></li>
- <li>GCC bootstrap now uses slim LTO object files.</li>
- <li>Memory usage and link times were improved. Tree merging was sped up,
- memory usage of GIMPLE declarations and types was reduced, and,
- support for on-demand streaming of variable constructors was added.</li>
+ <li><code>warning</code> and <code>error</code> attributes are now
+ correctly preserved by declaration linking and thus
+ <code>-D_FORTIFY_SOURCE=2</code> is now supported with <code>-flto</code>.</li>
+ <li><p>Type merging was fixed to handle C and Fortran interoperability
+ rules as defined by the Fortran 2008 language standard.</p>
+ <p>
+ As an exception, <code>CHARACTER(KIND=C_CHAR)</code> is not inter-operable
+ with <code>char</code> in all cases because it is an array while
+ <code>char</code> is scalar.
+ <code>INTEGER(KIND=C_SIGNED_CHAR)</code> should be used instead.
+ In general, this inter-operability cannot be implemented, for
+ example, on targets where function passing conventions of arrays
+ differs from scalars.</p></li>
+ <li>More type information is now preserved at link time reducing
+ the loss of accuracy of the type based alias analysis compared
+ to builds without link-time optimization.</li>
+ <li>Invalid type punning on global variables and declarations is now
+ reported with <code>-Wodr-type-mismatch</code>.</li>
+ <li>The size of LTO object files was reduced by about 11% (measured
+ by compiling Firefox 46.0).</li>
+ <li>Link-time parallelization (enabled using <code>-flto=n</code>)
+ was significantly improved by decreasing the size of streamed
+ data when partitioning programs. The size of streamed
+ IL while compiling Firefox 46.0 was reduced by 66%.</li>
+ <li><p>The linker plugin was extended to pass information about type of
+ binary produced to GCC back end (that can be also manually controlled
+ by <code>-flinker-output</code>). This makes it possible to
+ properly configure the code generator and support incremental
+ linking. Incremental linking of LTO objects by <code>gcc -r</code> is
+ now supported on plugin-enabled setups.</p>
+ <p>There are two ways to perform incremental linking:</p>
+ <ol>
+ <li>Linking by <code>ld -r</code> will result in an object file
+ with all sections from individual object files mechanically merged.
+ This delays the actual link time optimization to final linking step
+ and thus permits whole program optimization. Linking final binary
+ with such object files is however slower.</li>
+ <li>Linking by <code>gcc -r</code> will lead to link time optimization
+ and produce final binary into the object file. Linking such object
+ file is fast but avoids any benefits from whole program optimization.</li>
+ </ol>
+ GCC 7 will support incremental link-time optimization with <code>gcc -r</code>.</li>
</ul></li>
- <li>Feedback directed optimization improvements:
- <ul>
- <li>A new auto-FDO mode uses profiles collected by low overhead
- profiling tools (perf) instead of more expensive program
- instrumentation (via <code>-fprofile-generate</code>). SPEC2006
- benchmarks on x86-64 improve by 4.7% with auto-FDO and by 7.3% with
- traditional feedback directed optimization.</li>
- <li>Profile precision was improved in presence of C++ inline and extern
- inline functions.</li>
- <li>The new <code>gcov-tool</code> utility allows manipulating
- profiles.</li>
- <li>Profiles are now more tolerant to source file changes (this can be
- controlled by <code>--param profile-func-internal-id</code>).</li>
- </ul></li>
- <li>Register allocation improvements:
+ <li>Inter-procedural optimization improvements:
<ul>
- <li>A new local register allocator (LRA) sub-pass, controlled by
- <code>-flra-remat</code>, implements control-flow sensitive
- global register rematerialization. Instead of spilling and
- restoring a register value, it is recalculated if it is
- profitable. The sub-pass improved SPEC2000 generated code
- by 1% and 0.5% correspondingly on ARM and x86-64.</li>
- <li>Reuse of the PIC hard register, instead of using a fixed
- register, was implemented on x86/x86-64 targets. This
- improves generated PIC code performance as more hard
- registers can be used. Shared libraries can significantly
- benefit from this optimization. Currently it is switched on
- only for x86/x86-64 targets. As RA infrastructure is
- already implemented for PIC register reuse, other targets
- might follow this in the future.</li>
- <li>A simple form of inter-procedural RA was implemented. When
- it is known that a called function does not use caller-saved
- registers, save/restore code is not generated around the
- call for such registers. This optimization can be controlled
- by <code>-fipa-ra</code></li>
- <li>LRA is now much more effective at generating spills of
- general registers into vector registers instead of memory on
- architectures (e.g., modern Intel processors) where this is
- profitable.</li>
+ <li>Basic jump threading is now performed before profile construction
+ and inline analysis, resulting in more realistic size and time estimates
+ that drive the heuristics of the of inliner and function cloning passes.</li>
+ <li>Function cloning now more aggressively eliminates unused function
+ parameters.</li>
</ul></li>
- <li>UndefinedBehaviorSanitizer gained a few new sanitization options:
- <ul>
- <li><code>-fsanitize=float-divide-by-zero</code>: detect floating-point
- division by zero;</li>
- <li><code>-fsanitize=float-cast-overflow</code>: check that the result
- of floating-point type to integer conversions do not overflow;</li>
- <li><code>-fsanitize=bounds</code>: enable instrumentation of array
- bounds and detect out-of-bounds accesses;</li>
- <li><code>-fsanitize=alignment</code>: enable alignment checking, detect
- various misaligned objects;</li>
- <li><code>-fsanitize=object-size</code>: enable object size checking, detect
- various out-of-bounds accesses.</li>
- <li><code>-fsanitize=vptr</code>: enable checking of C++ member function
- calls, member accesses and some conversions between pointers to base
- and derived classes, detect if the referenced object does not have
- the correct dynamic type.</li>
- </ul>
- </li>
- <li>Pointer Bounds Checker, a bounds violation detector, has been added and
- can be enabled via <code>-fcheck-pointer-bounds</code>. Memory accesses are
- instrumented with run-time checks of used pointers against their bounds to
- detect pointer bounds violations (overflows). The Pointer Bounds Checker
- is available on x86/x86-64 GNU/Linux targets with a new ISA extension
- Intel MPX support. See the Pointer Bounds Checker
- <a href="https://gcc.gnu.org/wiki/Intel%20MPX%20support%20in%20the%20GCC%20compiler">
- Wiki page</a> for more details.
- </li>
</ul>
+<!-- .................................................................. -->
<h2 id="languages">New Languages and Language specific improvements</h2>
- <ul>
- <li id="offload"><a href="http://www.openmp.org/mp-documents/OpenMP4.0.0.pdf">
- OpenMP 4.0 specification</a> offloading features are now supported by the C, C++,
- and Fortran compilers. Generic changes:
- <ul>
- <li>Infrastructure (suitable for any vendor).</li>
- <li>Testsuite which covers offloading from the
- <a href="http://openmp.org/mp-documents/OpenMP4.0.0.Examples.pdf">
- OpenMP 4.0 Examples</a> document.</li>
- </ul>
- Specific for upcoming Intel Xeon Phi products:
+
+<!-- <ul>
+ <li> -->Compared to GCC 5, the GCC 6 release series includes a much improved
+ implementation of the <a href="http://www.openacc.org/">OpenACC 2.0a
+ specification</a>. Highlights are:
+ <ul>
+ <li>In addition to single-threaded host-fallback execution, offloading is
+ supported for nvptx (Nvidia GPUs) on x86_64 and PowerPC 64-bit
+ little-endian GNU/Linux host systems. For nvptx offloading, with the
+ OpenACC parallel construct, the execution model allows for an arbitrary
+ number of gangs, up to 32 workers, and 32 vectors.</li>
+ <li>Initial support for parallelized execution of OpenACC kernels
+ constructs:
<ul>
- <li>Run-time library.</li>
- <li>Card emulator.</li>
+ <li>Parallelization of a kernels region is switched on
+ by <code>-fopenacc</code> combined with <code>-O2</code> or
+ higher.</li>
+ <li>Code is offloaded onto multiple gangs, but executes with just one
+ worker, and a vector length of 1.</li>
+ <li>Directives inside a kernels region are not supported.</li>
+ <li>Loops with reductions can be parallelized.</li>
+ <li>Only kernels regions with one loop nest are parallelized.</li>
+ <li>Only the outer-most loop of a loop nest can be parallelized.</li>
+ <li>Loop nests containing sibling loops are not parallelized.</li>
</ul>
- </li>
- <li id="openacc">
- GCC 5 includes a preliminary implementation of the OpenACC 2.0a
- specification. OpenACC is intended for programming accelerator devices
- such as GPUs. See <a href="https://gcc.gnu.org/wiki/OpenACC">the OpenACC
- wiki page</a> for more information.
- </li>
- </ul>
-
+ Typically, using the OpenACC parallel construct gives much better
+ performance, compared to the initial support of the OpenACC kernels
+ construct.</li>
+ <li>The <code>device_type</code> clause is not supported.
+ The <code>bind</code> and <code>nohost</code> clauses are not
+ supported. The <code>host_data</code> directive is not supported in
+ Fortran.</li>
+ <li>Nested parallelism (cf. CUDA dynamic parallelism) is not
+ supported.</li>
+ <li>Usage of OpenACC constructs inside multithreaded contexts (such as
+ created by OpenMP, or pthread programming) is not supported.</li>
+ <li>If a call to the <code>acc_on_device</code> function has a
+ compile-time constant argument, the function call evaluates to a
+ compile-time constant value only for C and C++ but not for
+ Fortran.</li>
+ </ul>
+ See the <a href="https://gcc.gnu.org/wiki/OpenACC">OpenACC</a>
+ and <a href="https://gcc.gnu.org/wiki/Offloading">Offloading</a> wiki pages
+ for further information.
+ <!-- </li>
+</ul> -->
-<!-- h3 id="ada">Ada</h3 -->
+<!-- <h3 id="ada">Ada</h3> -->
<h3 id="c-family">C family</h3>
<ul>
- <li>The default setting of the <code>-fdiagnostics-color=</code>
- command-line option is now
- <a href="https://gcc.gnu.org/install/configure.html">configurable
- when building GCC</a> using configuration option
- <code>--with-diagnostics-color=</code>. The possible values
- are: <code>never</code>, <code>always</code>, <code>auto</code>
- and <code>auto-if-env</code>. The new
- default <code>auto</code> uses color only when the
- standard error is a terminal. The default in GCC 4.9
- was <code>auto-if-env</code>, which is equivalent to
- <code>auto</code> if there is a
- non-empty <code>GCC_COLORS</code> environment variable,
- and <code>never</code> otherwise. As in GCC 4.9, an empty
- <code>GCC_COLORS</code> variable in the environment will
- always disable colors, no matter what the default is or what
- command-line options are used.</li>
- <li>A new command-line option <code>-Wswitch-bool</code> has been added for
- the C and C++ compilers, which warns whenever a <code>switch</code>
- statement has an index of boolean type.</li>
- <li>A new command-line option <code>-Wlogical-not-parentheses</code> has
- been added for the C and C++ compilers, which warns about "logical not"
- used on the left hand side operand of a comparison.</li>
- <li>A new command-line option <code>-Wsizeof-array-argument</code> has been
- added for the C and C++ compilers, which warns when the
- <code>sizeof</code> operator is applied to a parameter that has been
- declared as an array in a function definition.</li>
- <li>A new command-line option <code>-Wbool-compare</code> has been added
- for the C and C++ compilers, which warns about boolean expressions
- compared with an integer value different from
- <code>true</code>/<code>false</code>.</li>
- <li>Full support for <a href="https://www.cilkplus.org/">Cilk Plus</a>
- has been added to the GCC compiler. Cilk Plus is an extension to
- the C and C++ languages to support data and task parallelism.</li>
- <li>A new attribute <code>no_reorder</code> prevents reordering of
- selected symbols against other such symbols or inline assembler.
- This enables to link-time optimize the Linux kernel without having
- to resort to <code>-fno-toplevel-reorder</code> that disables
- several optimizations.</li>
- <li>New preprocessor constructs, <code>__has_include</code>
- and <code>__has_include_next</code>, to test the availability of headers
- have been added.<br/>
- This demonstrates a way to include the header <code><optional></code>
- only if it is available:<br/>
+ <li>Version 4.5 of the <a href="http://openmp.org/wp/openmp-specifications/"
+ >OpenMP specification</a> is now supported in the C and C++ compilers.</li>
+
+ <li>The C and C++ compilers now support attributes on enumerators. For instance,
+ it is now possible to mark enumerators as deprecated:
<blockquote><pre>
-#ifdef __has_include
-# if __has_include(<optional>)
-# include <optional>
-# define have_optional 1
-# elif __has_include(<experimental/optional>)
-# include <experimental/optional>
-# define have_optional 1
-# define experimental_optional
-# else
-# define have_optional 0
-# endif
-#endif
-</pre></blockquote>
- The header search paths for <code>__has_include</code>
- and <code>__has_include_next</code> are equivalent to those
- of the standard directive <code>#include</code>
- and the extension <code>#include_next</code> respectively.
- </li>
- <li>A new built-in function-like macro to determine the existence of an
- attribute, <code>__has_attribute</code>, has been added.
- The equivalent built-in macro <code>__has_cpp_attribute</code> was
- added to C++ to support
- <a href="http://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations">
- Feature-testing recommendations for C++</a>.
- The macro <code>__has_attribute</code> is added to all C-like
- languages as an extension:
+enum {
+ newval,
+ oldval __attribute__ ((deprecated ("too old")))
+};
+</pre></blockquote></li>
+<li>Source locations for the C and C++ compilers are now tracked as ranges,
+ rather than just points, making it easier to identify the subexpression
+ of interest within a complicated expression.
+ For example:
<blockquote><pre>
-int
-#ifdef __has_attribute
-# if __has_attribute(__noinline__)
- __attribute__((__noinline__))
-# endif
-#endif
-foo(int x);
+<b>test.cc:</b> In function <b>'int test(int, int, foo, int, int)'</b>:
+<b>test.cc:5:16:</b> <span class="boldred">error:</span> no match for <b>'operator*'</b> (operand types are <b>'int'</b> and <b>'foo'</b>)
+ return p + <span class="boldred">q * r</span> * s + t;
+ <span class="boldred">~~^~~</span>
</pre></blockquote>
- If an attribute exists, a nonzero constant integer is returned.
- For standardized C++ attributes a date is returned, otherwise the
- constant returned is 1.
- Both <code>__has_attribute</code> and
- <code>__has_cpp_attribute</code> will add underscores to an
- attribute name if necessary to resolve the name.
- For C++11 and onwards the attribute may be scoped.
- </li>
- <li>A new set of built-in functions for arithmetics with overflow checking
- has been added: <code>__builtin_add_overflow</code>,
- <code>__builtin_sub_overflow</code> and <code>__builtin_mul_overflow</code>
- and for compatibility with clang also other variants.
- These builtins have two integral arguments (which don't need to have
- the same type), the arguments are extended to infinite precision
- signed type, <code>+</code>, <code>-</code> or <code>*</code>
- is performed on those, and the result is stored in an integer
- variable pointed to by the last argument. If the stored value is
- equal to the infinite precision result, the built-in functions return
- <code>false</code>, otherwise <code>true</code>. The type of
- the integer variable that will hold the result can be different from
- the types of the first two arguments. The following snippet
- demonstrates how this can be used in computing the size for the
- <code>calloc</code> function:
+In addition, there is now initial support for precise diagnostic locations
+within strings:
+<blockquote><pre>
+<b>format-strings.c:3:14:</b> <span class="boldmagenta">warning:</span> field width specifier <b>'*'</b> expects a matching <b>'int'</b> argument [<span class="boldmagenta">-Wformat=</span>]
+ printf("%*d");
+ <span class="boldmagenta">^</span>
+</pre></blockquote></li>
+ <li>Diagnostics can now contain "fix-it hints", which are displayed
+ in context underneath the relevant source code. For example:
+ <!-- this is currently the only example in the tree; various others are pending -->
+<blockquote><pre>
+<b>fixits.c:</b> In function <b>'bad_deref'</b>:
+<b>fixits.c:11:13:</b> <span class="boldred">error:</span> <b>'ptr'</b> is a pointer; did you mean to use <b>'->'</b>?
+ return ptr<span class="boldred">.</span>x;
+ <span class="boldred">^</span>
+ <span class="boldred">-></span>
+</pre></blockquote></li>
+ <li>The C and C++ compilers now offer suggestions for misspelled field names:
+<blockquote><pre>
+<b>spellcheck-fields.cc:52:13:</b> <span class="boldred">error:</span> <b>'struct s'</b> has no member named <b>'colour'</b>; did you mean <b>'color'</b>?
+ return ptr-><span class="boldred">colour</span>;
+ <span class="boldred">^~~~~~</span>
+</pre></blockquote></li>
+ <!-- also, pending patch to add fix-it hints to the above -->
+ <li>New command-line options have been added for the C and C++ compilers:
+ <ul>
+ <li><code>-Wshift-negative-value</code> warns about left shifting a
+ negative value.</li>
+ <li><code>-Wshift-overflow</code> warns about left shift overflows.
+ This warning is enabled by default.
+ <code>-Wshift-overflow=2</code> also warns about left-shifting 1 into
+ the sign bit.</li>
+ <li><code>-Wtautological-compare</code> warns if a self-comparison
+ always evaluates to true or false. This warning is enabled by
+ <code>-Wall</code>.</li>
+ <li><code>-Wnull-dereference</code> warns if the compiler detects paths
+ that trigger erroneous or undefined behavior due to dereferencing a
+ null pointer. This option is only active when
+ <code>-fdelete-null-pointer-checks</code> is active, which is enabled
+ by optimizations in most targets. The precision of the warnings
+ depends on the optimization options used.</li>
+ <li><code>-Wduplicated-cond</code> warns about duplicated conditions
+ in an if-else-if chain.</li>
+ <li><code>-Wmisleading-indentation</code> warns about places where the
+ indentation of the code gives a misleading idea of the block
+ structure of the code to a human reader. For example, given
+ <a href="https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-1266">CVE-2014-1266</a>:
<blockquote><pre>
-void *
-calloc (size_t x, size_t y)
-{
- size_t sz;
- if (__builtin_mul_overflow (x, y, &sz))
- return NULL;
- void *ret = malloc (sz);
- if (ret) memset (res, 0, sz);
- return ret;
-}
+<b>sslKeyExchange.c:</b> In function <b>'SSLVerifySignedServerKeyExchange'</b>:
+<b>sslKeyExchange.c:629:3:</b> <span class="boldmagenta">warning:</span> this <b>'if'</b> clause does not guard... [<span class="boldmagenta">-Wmisleading-indentation</span>]
+ <span class="boldcyan">if</span> ((err = SSLHashSHA1.update(&hashCtx, &signedParams)) != 0)
+ <span class="boldcyan">^~</span>
+<b>sslKeyExchange.c:631:5:</b> <span class="boldcyan">note:</span> ...this statement, but the latter is misleadingly indented as if it is guarded by the <b>'if'</b>
+ <span class="boldmagenta">goto</span> fail;
+ <span class="boldmagenta">^~~~</span>
</pre></blockquote>
- On e.g. i?86 or x86-64 the above will result in a <code>mul</code>
- instruction followed by a jump on overflow.
+ This warning is enabled by <code>-Wall</code>.</li>
+ </ul>
</li>
- <li>The option <code>-fextended-identifiers</code> is now enabled
- by default for C++, and for C99 and later C versions. Various
- bugs in the implementation of extended identifiers have been
- fixed.</li>
+ <li>The C and C++ compilers now emit saner error messages if
+ merge-conflict markers are present in a source file.
+<blockquote><pre>
+<b>test.c:3:1:</b> <span class="boldred">error:</span> version control conflict marker in file
+ <span class="boldred"><<<<<<<</span> HEAD
+ <span class="boldred">^~~~~~~</span>
+</pre></blockquote></li>
</ul>
<h3 id="c">C</h3>
<ul>
- <li>The default mode has been changed to <code>-std=gnu11</code>.</li>
- <li>A new command-line option <code>-Wc90-c99-compat</code> has been added
- to warn about features not present in ISO C90, but present in ISO
- C99.</li>
- <li>A new command-line option <code>-Wc99-c11-compat</code> has been added
- to warn about features not present in ISO C99, but present in ISO
- C11.</li>
- <li>It is possible to disable warnings about conversions between pointers
- that have incompatible types via a new warning option
- <code>-Wno-incompatible-pointer-types</code>; warnings about implicit
- incompatible integer to pointer and pointer to integer conversions via
- a new warning option <code>-Wno-int-conversion</code>; and warnings
- about qualifiers on pointers being discarded via a new warning option
- <code>-Wno-discarded-qualifiers</code>.</li>
- <li>To allow proper use of const qualifiers with multidimensional arrays,
- GCC will not warn about incompatible pointer types anymore for
- conversions between pointers to arrays with and without const qualifier
- (except when using <code>-pedantic</code>). Instead, a new warning is
- emitted only if the const qualifier is lost. This can be controlled with
- a new warning option <code>-Wno-discarded-array-qualifiers</code>.</li>
- <li>The C front end now generates more precise caret diagnostics.</li>
- <li>The <code>-pg</code> command-line option now only affects the current
- file in an LTO build.</li>
+ <li>It is possible to disable warnings when an initialized field of
+ a structure or a union with side effects is being overridden when
+ using designated initializers via a new warning option
+ <code>-Woverride-init-side-effects</code>.</li>
+ <li>A new type attribute <code>scalar_storage_order</code> applying to
+ structures and unions has been introduced. It specifies the storage
+ order (aka endianness) in memory of scalar fields in structures
+ or unions.</li>
</ul>
<h3 id="cxx">C++</h3>
-<ul>
- <li>G++ now supports <a href="../projects/cxx1y.html">C++14</a> variable
- templates.</li>
- <li><code>-Wnon-virtual-dtor</code> doesn't warn anymore
- for <code>final</code> classes.</li>
- <li>Excessive template instantiation depth is now a fatal error. This
- prevents excessive diagnostics that usually do not help to identify the
- problem.</li>
- <li>G++ and libstdc++ now implement the feature-testing macros from
- <a href="http://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations">Feature-testing
- recommendations for C++</a>.</li>
- <li>G++ now allows <code>typename</code> in a template template parameter.
- <blockquote><pre>
-template<template<typename> <b>typename</b> X> struct D; // OK</pre></blockquote>
- </li>
- <li>G++ now supports <a href="../projects/cxx1y.html">C++14</a> aggregates with non-static data member initializers.
- <blockquote><pre>
-struct A { int i, j = i; };
-A a = { 42 }; // a.j is also 42</pre></blockquote>
- </li>
- <li>G++ now supports <a href="../projects/cxx1y.html">C++14</a> extended <code>constexpr</code>.
- <blockquote><pre>
-constexpr int f (int i)
-{
- int j = 0;
- for (; i > 0; --i)
- ++j;
- return j;
-}
-
-constexpr int i = f(42); // i is 42</pre></blockquote>
- </li>
- <li>G++ now supports the <a href="../projects/cxx1y.html">C++14</a> sized
- deallocation functions.
- <blockquote><pre>
-void operator delete (void *, std::size_t) noexcept;
-void operator delete[] (void *, std::size_t) noexcept;</pre></blockquote>
- </li>
- <li>A new One Definition Rule violation warning (controlled by <code>-Wodr</code>)
- detects mismatches in type definitions and virtual table contents
- during link-time optimization.</li>
- <li>New warnings <code>-Wsuggest-final-types</code> and
- <code>-Wsuggest-final-methods</code> help developers
- to annotate programs with <code>final</code> specifiers (or anonymous
- namespaces) to improve code generation.
- These warnings can be used at compile time, but they are more
- useful in combination with link-time optimization.</li>
-<li>G++ no longer supports
- <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3639.html">N3639</a>
- variable length arrays, as they were removed from the C++14 working paper
- prior to ratification. GNU VLAs are still supported, so VLA support is
- now the same in C++14 mode as in C++98 and C++11 modes.</li>
-<li>G++ now allows passing a non-trivially-copyable class via C varargs,
- which is conditionally-supported with implementation-defined semantics in
- the standard. This uses the same calling convention as a normal value
- parameter.</li>
-<li>G++ now defaults to <code>-fabi-version=0</code>
-and <code>-fabi-compat-version=2</code>. So various mangling bugs are
-fixed, but G++ will still emit aliases with the old, wrong mangling where
-feasible. <code>-Wabi</code> continues to warn about differences.</li>
-</ul>
-
- <h4 id="libstdcxx">Runtime Library (libstdc++)</h4>
<ul>
- <li>A <a href="/onlinedocs/gcc-5.1.0/libstdc++/manual/using_dual_abi.html">Dual
- ABI</a> is provided by the library. A new ABI is enabled by default.
- The old ABI is still supported and can be used by defining the macro
- <code>_GLIBCXX_USE_CXX11_ABI</code> to <code>0</code> before
- including any C++ standard library headers. </li>
- <li>A new implementation of <code>std::string</code> is enabled by default,
- using the <em>small string optimization</em> instead of
- <em>copy-on-write</em> reference counting.</li>
- <li> A new implementation of <code>std::list</code> is enabled by default,
- with an O(1) <code>size()</code> function; </li>
- <li><a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/libstdc++/manual/status.html#status.iso.2011">
- Full support for C++11</a>, including the following new features:
+ <li>The default mode has been changed to <code>-std=gnu++14</code>.</li>
+ <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4377.pdf">C++
+ Concepts</a> are now supported when compiling with
+ <code>-fconcepts</code>.</li>
+ <li><code>-flifetime-dse</code> is more
+ aggressive in dead-store elimination in situations where
+ a memory store to a location precedes a constructor to the
+ memory location.</li>
+ <li>G++ now supports
+ <a href="https://gcc.gnu.org/projects/cxx-status.html#cxx1z.html">C++17</a>
+ fold expressions, <code>u8</code> character literals,
+ extended <code>static_assert</code>, and nested namespace definitions.</li>
+ <li>G++ now allows constant evaluation for all non-type template arguments.</li>
+ <li>G++ now supports C++ Transactional Memory when compiling with
+ <code>-fgnu-tm</code>. </li>
+ </ul>
+
+<h4 id="libstdcxx">Runtime Library (libstdc++)</h4>
+ <ul>
+ <li>Extensions to the C++ Library to support mathematical special
+ functions (ISO/IEC 29124:2010), thanks to Edward Smith-Rowland. </li>
+ <li>Experimental support for C++17, including the following
+ new features:
<ul>
- <li> <code>std::deque</code> and <code>std::vector<bool></code>
- meet the allocator-aware container requirements;</li>
- <li> movable and swappable iostream classes;</li>
- <li> support for <code>std::align</code> and
- <code>std::aligned_union</code>;</li>
- <li> type traits <code>std::is_trivially_copyable</code>,
- <code>std::is_trivially_constructible</code>,
- <code>std::is_trivially_assignable</code> etc.;
- </li>
- <li> I/O manipulators <code>std::put_time</code>, <code>std::get_time</code>,
- <code>std::hexfloat</code> and <code>std::defaultfloat</code>;
- </li>
- <li> generic locale-aware <code>std::isblank</code>; </li>
- <li> locale facets for Unicode conversion; </li>
- <li> atomic operations for <code>std::shared_ptr</code>; </li>
- <li> <code>std::notify_all_at_thread_exit()</code> and functions
- for making futures ready at thread exit.</li>
+ <li><code>std::uncaught_exceptions</code> function (this is also
+ available for <tt>-std=gnu++NN</tt> modes); </li>
+ <li>new member functions <code>try_emplace</code> and
+ <code>insert_or_assign</code> for unique_key maps;</li>
+ <li>non-member functions <code>std::size</code>,
+ <code>std::empty</code>, and <code>std::data</code> for
+ accessing containers and arrays;</li>
+ <li><code>std::invoke</code>;</li>
+ <li><code>std::shared_mutex</code>;</li>
+ <li><code>std::void_t</code> and <code>std::bool_constant</code>
+ metaprogramming utilities. </li>
</ul>
+ Thanks to Ville Voutilainen for contributing many of the C++17 features.
</li>
- <li> Support for the C++11 <code>hexfloat</code> manipulator changes how
- the <code>num_put</code> facet formats floating point types when
- <code>ios_base::fixed|ios_base::scientific</code> is set in a stream's
- <code>fmtflags</code>. This change affects all language modes, even
- though the C++98 standard gave no special meaning to that combination
- of flags. To prevent the use of hexadecimal notation for floating point
- types use <code>str.unsetf(std::ios_base::floatfield)</code> to clear
- the relevant bits in <code>str.flags()</code>.
+ <li>An experimental implementation of the File System TS.</li>
+ <li>Experimental support for most features of the second version of the
+ Library Fundamentals TS. This includes polymorphic memory resources
+ and array support in <code>shared_ptr</code>, thanks to Fan You.</li>
+ <li>Some assertions checked by Debug Mode can now also be enabled by
+ <code>_GLIBCXX_ASSERTIONS</code>. The subset of checks enabled by
+ the new macro have less run-time overhead than the full
+ <code>_GLIBCXX_DEBUG</code> checks and don't affect the library
+ ABI, so can be enabled per-translation unit.
</li>
- <li><a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/libstdc++/manual/status.html#status.iso.2014">
- Full experimental support for C++14</a>, including the following
- new features:
- <ul>
- <li> <code>std::is_final</code> type trait; </li>
- <li> heterogeneous comparison lookup in associative containers. </li>
- <li> global functions <code>cbegin</code>, <code>cend</code>, <code>rbegin</code>,
- <code>rend</code>, <code>crbegin</code>, and <code>crend</code> for
- range access to containers, arrays and initializer lists. </li>
- </ul>
+ <li>Timed mutex types are supported on more targets, including Darwin.
</li>
- <li><a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/libstdc++/manual/status.html#status.iso.2014">
- Improved experimental support for the Library Fundamentals TS</a>, including:
- <ul>
- <li> class <code>std::experimental::any</code>; </li>
- <li> function template <code>std::experimental::apply</code>; </li>
- <li> function template <code>std::experimental::sample</code>; </li>
- <li> function template <code>std::experimental::search</code> and
- related searcher types; </li>
- <li> variable templates for type traits; </li>
- <li> function template <code>std::experimental::not_fn</code>.</li>
- </ul>
+ <li>Improved <code>std::locale</code> support for DragonFly and FreeBSD,
+ thanks to John Marino and Andreas Tobler.
</li>
- <li>New random number distributions <code>logistic_distribution</code> and
- <code>uniform_on_sphere_distribution</code> as extensions.</li>
- <li><a href="https://sourceware.org/gdb/current/onlinedocs/gcc-5.1.0/gdb/Xmethods-In-Python.html">GDB
- Xmethods</a> for containers and <code>std::unique_ptr</code>.</li>
</ul>
-<h3 id="fortran">Fortran</h3>
- <ul>
- <li>Compatibility notice:<ul>
- <li>The version of the module files (.mod) has been incremented.</li>
- <li>For free-form source files,
- <a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/gfortran/Error-and-Warning-Options.html"><code>-Werror=line-truncation</code></a>
- is now enabled by default; note that comments exceeding the line length
- are not diagnosed. (For fixed-form source code, the same warning is
- available but turned off by default, such that excess characters are
- ignored. <code>-ffree-line-length-<em>n</em></code> and
- <code>-ffixed-line-length-<em>n</em></code> can be used to modify the
- default line lengths of 132 and 72 columns, respectively.)</li>
- <li>The <code>-Wtabs</code> option is now more sensible: with
- <code>-Wtabs</code> the compiler warns if it encounters tabs and with
- <code>-Wno-tabs</code> this warning is turned off. Before,
- <code>-Wno-tabs</code> warned and <code>-Wtabs</code> turned the warning
- off. As before, the warning is also enabled by <code>-Wall</code>,
- <code>-pedantic</code> and the <code>f95</code>, <code>f2003</code>,
- <code>f2008</code> and <code>f2008ts</code> options of <code>-std=</code>.</li>
- </ul></li>
- <li>Incomplete support for colorizing diagnostics emitted by
- gfortran has been added. The
- option <code><a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/gcc/Language-Independent-Options.html"
- >-fdiagnostics-color</a></code> controls when color is used in
- diagnostics. The default value of this option can
- be <a href="https://gcc.gnu.org/install/configure.html">configured
- when building GCC</a>. The <code>GCC_COLORS</code> environment
- variable can be used to customize the colors or disable coloring
- completely. Sample diagnostics output:<br/>
- <pre>
- $ gfortran -fdiagnostics-color=always -Wuse-without-only test.f90
- <b>test.f90:6:1:</b>
-
- 0 continue
- <b style='color:lime'>1</b>
- <b style='color:red'>Error:</b> Zero is not a valid statement label at (1)
- <b>test.f90:9:6:</b>
-
- USE foo
- <b style='color:lime'>1</b>
- <b style='color:magenta'>Warning:</b> USE statement at (1) has no ONLY qualifier [-Wuse-without-only]
- </pre></li>
-
- <li>The <code>-Wuse-without-only</code> option has been added to warn when a
- <code>USE</code> statement has no <code>ONLY</code> qualifier and, thus,
- implicitly imports all public entities of the used module.</li>
- <li>Formatted READ and WRITE statements now work correctly in locale-aware
- programs. For more information and potential caveats, see
- <a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/gfortran/Thread-safety-of-the-runtime-library.html">Section
- 5.3 Thread-safety of the runtime library in the manual</a>.</li>
- <li><a href="https://gcc.gnu.org/wiki/Fortran2003Status">Fortran 2003</a>:
- <ul>
- <li>The intrinsic IEEE modules (<code>IEEE_FEATURES</code>,
- <code>IEEE_EXCEPTIONS</code> and <code>IEEE_ARITHMETIC</code>) are
- now supported.</li>
- </ul></li>
- <li><a href="https://gcc.gnu.org/wiki/Fortran2008Status">Fortran 2008</a>:
- <ul>
- <li><a href="https://gcc.gnu.org/wiki/Coarray">Coarrays</a>: Full
- experimental support of Fortran 2008's coarrays with
- <code>-fcoarray=lib</code> except for allocatable/pointer
- components of derived-type coarrays. GCC currently only ships with a
- single-image library (<code>libcaf_single</code>), but
- multi-image support based on MPI and GASNet is provided by the libraries
- of the <a href="http://www.opencoarrays.org/">OpenCoarrays project</a>.
- </li>
- </ul></li>
- <li>TS18508 Additional Parallel Features in Fortran:
- <ul>
- <li>Support for the collective intrinsic subroutines <code>CO_MAX</code>,
- <code>CO_MIN</code>, <code>CO_SUM</code>, <code>CO_BROADCAST</code> and
- <code>CO_REDUCE</code> has been added, including
- <code>-fcoarray=lib</code> support.</li>
- <li>Support for the new atomic intrinsics has been added, including
- <code>-fcoarray=lib</code> support.</li>
- </ul></li>
- <li>Fortran 2015:
- <ul>
- <li>Support for <code>IMPLICIT NONE (external, type)</code>.</li>
- <li><code>ERROR STOP</code> is now permitted in pure procedures.</li>
- </ul></li>
- </ul>
-<h3 id="go">Go</h3>
+<h3 id="fortran">Fortran</h3>
<ul>
- <li>GCC 5 provides a complete implementation of the Go 1.4.2
- release.</li>
- <li>Building GCC 5 with Go enabled will install two new
- programs: <a href="http://golang.org/cmd/go">go</a>
- and <a href="http://golang.org/cmd/gofmt">gofmt</a>.</li>
+ <li>The <code>MATMUL</code> intrinsic is now inlined for straightforward
+ cases if front-end optimization is active. The maximum size for
+ inlining can be set to <code>n</code> with the
+ <code>-finline-matmul-limit=n</code> option and turned off
+ with <code>-finline-matmul-llimit=0</code>.</li>
+ <li>The <code>-Wconversion-extra</code> option will warn about
+ <code>REAL</code> constants which have excess precision for
+ their kind.</li>
+ <li>The <code>-Winteger-division</code> option has been added, which
+ warns about divisions of integer constants which are truncated.
+ This option is included in <code>-Wall</code> by default.</li>
</ul>
-<!--h3 id="java">Java (GCJ)</h3-->
-
-<h2 id="jit">libgccjit</h2>
-<p>New in GCC 5 is the ability to build GCC as a shared library for embedding
-in other processes (such as interpreters), suitable for Just-In-Time
-compilation to machine code.</p>
+<!-- <h3 id="go">Go</h3> -->
-<p>The shared library has a <a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/intro/index.html">C API</a>
-and a
-<a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/cp/index.html">C++ wrapper API</a>
-providing some "syntactic sugar".
-There are also bindings available from 3rd parties for
-<a href="https://github.com/davidmalcolm/pygccjit">Python</a> and for
-<a href="https://github.com/ibuclaw/gccjitd">D</a>.</p>
+<!-- <h3 id="java">Java (GCJ)</h3> -->
-<p>For example, this library can be used by interpreters for
-<a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/intro/tutorial04.html">compiling
-functions from bytecode to machine code</a>.</p>
-<p>The library can also be used for ahead-of-time compilation, enabling
-GCC to be plugged into a pre-existing frontend. An example of using
-this to build a compiler for an esoteric language we'll refer to as "brainf"
-can be seen <a href="https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/intro/tutorial05.html">
-here</a>.</p>
-
-<p>libgccjit is licensed under the GPLv3 (or at your option, any later version)</p>
-
-<p>It should be regarded as experimental at this time.</p>
+<!-- .................................................................. -->
+<h2 id="jit">libgccjit</h2>
+ <ul>
+ <li>The driver code is now run in-process within libgccjit,
+ providing a small speed-up of the compilation process.</li>
+ <li>The API has gained entrypoints for
+ <ul>
+ <li><a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/performance.html">timing how long was spent in different parts of code</a>,</li>
+ <li><a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/functions.html#gcc_jit_block_end_with_switch">creating switch statements</a>,</li>
+ <li><a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/contexts.html#gcc_jit_context_set_bool_allow_unreachable_blocks">allowing unreachable basic blocks in a function</a>, and</li>
+ <li><a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/contexts.html#gcc_jit_context_add_command_line_option">adding arbitrary command-line options to a compilation</a>.</li>
+ </ul>
+ </li>
+ </ul>
+<!-- .................................................................. -->
<h2 id="targets">New Targets and Target Specific Improvements</h2>
<h3 id="aarch64">AArch64</h3>
<ul>
- <li>Code generation for the ARM Cortex-A57 processor has been improved.
- A more accurate instruction scheduling model for the processor is
- now used, and a number of compiler tuning parameters have been set
- to offer increased performance when compiling with
- <code>-mcpu=cortex-a57</code> or <code>-mtune=cortex-a57</code>.
- </li>
- <li> A workaround for the ARM Cortex-A53 erratum 835769 has been
- added and can be enabled by giving the
- <code>-mfix-cortex-a53-835769</code> option.
- Alternatively it can be enabled by default by configuring GCC with the
- <code>--enable-fix-cortex-a53-835769</code> option.
+ <li>
+ The new command line options <code>-march=native</code>,
+ <code>-mcpu=native</code> and <code>-mtune=native</code> are now
+ available on native AArch64 GNU/Linux systems. Specifying
+ these options will cause GCC to auto-detect the host CPU and
+ rewrite these options to the optimal setting for that system.
+ If GCC is unable to detect the host CPU these options have no effect.
</li>
- <li> The optional cryptographic extensions to the ARMv8-A architecture
- are no longer enabled by default when specifying the
- <code>-mcpu=cortex-a53</code>, <code>-mcpu=cortex-a57</code> or
- <code>-mcpu=cortex-a57.cortex-a53</code> options. To enable these
- extensions add <code>+crypto</code> to the value of
- <code>-mcpu</code> or <code>-march</code> e.g.
- <code>-mcpu=cortex-a53+crypto</code>.
+ <li>
+ <code>-fpic</code> is now supported by the AArch64 target when generating
+ code for the small code model (<code>-mcmodel=small</code>). The size of
+ the global offset table (GOT) is limited to 28KiB under the LP64 SysV ABI
+ , and 15KiB under the ILP32 SysV ABI.
</li>
- <li> Support has been added for the following processors
- (GCC identifiers in parentheses): ARM Cortex-A72
- (<code>cortex-a72</code>) and initial support for its big.LITTLE
- combination with the ARM Cortex-A53 (<code>cortex-a72.cortex-a53</code>),
- Cavium ThunderX (<code>thunderx</code>), Applied Micro X-Gene 1
- (<code>xgene1</code>), and Samsung Exynos M1 (<code>exynos-m1</code>).
- The GCC identifiers can be used
- as arguments to the <code>-mcpu</code> or <code>-mtune</code> options,
- for example: <code>-mcpu=xgene1</code> or
- <code>-mtune=cortex-a72.cortex-a53</code>.
- Using <code>-mcpu=cortex-a72</code> requires a version of GNU binutils
- that has support for the Cortex-A72.
+ <li>
+ The AArch64 port now supports target attributes and pragmas. Please
+ refer to the <a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes">
+ documentation</a> for details of available attributes and
+ pragmas as well as usage instructions.
</li>
- <li>The transitional options <code>-mlra</code> and <code>-mno-lra</code>
- have been removed. The AArch64 backend now uses the local register
- allocator (LRA) only.
+ <li>
+ Link-time optimization across translation units with different
+ target-specific options is now supported.
</li>
</ul>
<h3 id="arm">ARM</h3>
- <ul>
- <li>Thumb-1 assembly code is now generated in unified syntax. The new option
- <code>-masm-syntax-unified</code> specifies whether inline assembly
- code is using unified syntax. By default the option is off which means
- non-unified syntax is used. However this is subject to change in future releases.
- Eventually the non-unified syntax will be deprecated.
- </li>
- <li> It is now a configure-time error to use the <code>--with-cpu</code>
- configure option with either of <code>--with-tune</code> or
- <code>--with-arch</code>.
- </li>
- <li>Code generation for the ARM Cortex-A57 processor has been improved.
- A more accurate instruction scheduling model for the processor is
- now used, and a number of compiler tuning parameters have been set
- to offer increased performance when compiling with
- <code>-mcpu=cortex-a57</code> or <code>-mtune=cortex-a57</code>.
- </li>
- <li> Support has been added for the following processors
- (GCC identifiers in parentheses): ARM Cortex-A17 (<code>cortex-a17</code>) and
- initial support for its big.LITTLE combination with the ARM Cortex-A7
- (<code>cortex-a17.cortex-a7</code>), ARM Cortex-A72
- (<code>cortex-a72</code>) and initial support for its big.LITTLE
- combination with the ARM Cortex-A53 (<code>cortex-a72.cortex-a53</code>),
- ARM Cortex-M7 (<code>cortex-m7</code>), Applied Micro X-Gene 1
- (<code>xgene1</code>), and Samsung Exynos M1 (<code>exynos-m1</code>).
+ <ul>
+ <li>
+ Support for revisions of the ARM architecture prior to ARMv4t has
+ been deprecated and will be removed in a future GCC release.
+ The <code>-mcpu</code> and <code>-mtune</code> values that are
+ deprecated are:
+ <code>arm2, arm250, arm3, arm6, arm60, arm600, arm610, arm620, arm7,
+ arm7d, arm7di, arm70, arm700, arm700i, arm710, arm720, arm710c,
+ arm7100, arm7500, arm7500fe, arm7m, arm7dm, arm7dmi, arm8, arm810,
+ strongarm, strongarm110, strongarm1100, strongarm1110, fa526,
+ fa626</code>. The value
+ <code>arm7tdmi</code> is still supported.
+ The values of <code>-march</code> that are deprecated are:
+ <code>armv2,armv2a,armv3,armv3m,armv4</code>.
+ </li>
+ <li>
+ The ARM port now supports target attributes and pragmas. Please
+ refer to the <a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/ARM-Function-Attributes.html#ARM-Function-Attributes">
+ documentation</a> for details of available attributes and
+ pragmas as well as usage instructions.
+ </li>
+ <li>
+ Support has been added for the following processors
+ (GCC identifiers in parentheses): ARM Cortex-A32
+ (<code>cortex-a32</code>), ARM Cortex-A35 (<code>cortex-a35</code>).
The GCC identifiers can be used
as arguments to the <code>-mcpu</code> or <code>-mtune</code> options,
- for example: <code>-mcpu=xgene1</code> or
- <code>-mtune=cortex-a72.cortex-a53</code>.
- Using <code>-mcpu=cortex-a72</code> requires a version of GNU binutils
- that has support for the Cortex-A72.
- </li>
- <li> The deprecated option <code>-mwords-little-endian</code>
- has been removed.
- </li>
- <li> The options <code>-mapcs</code>, <code>-mapcs-frame</code>,
- <code>-mtpcs-frame</code> and <code>-mtpcs-leaf-frame</code>
- which are only applicable to the old ABI have been deprecated.
- </li>
- <li>The transitional options <code>-mlra</code> and <code>-mno-lra</code>
- have been removed. The ARM backend now uses the local register allocator
- (LRA) only.
+ for example: <code>-mcpu=cortex-a32</code> or
+ <code>-mtune=cortex-a35</code>.
</li>
- </ul>
+ </ul>
+<!-- <h3 id="avr">AVR</h3> -->
+
+<h3 id="hsa">Heterogeneous Systems Architecture</h3>
+ <ul>
+ <li><p>GCC can now generate HSAIL (Heterogeneous System Architecture
+ Intermediate Language) for simple OpenMP device constructs if
+ configured with <code>--enable-offload-targets=hsa</code>. A new
+ libgomp plugin then runs the HSA GPU kernels implementing these
+ constructs on HSA capable GPUs via a standard HSA run time.</p>
+
+ <p>If the HSA compilation back end determines it cannot output HSAIL
+ for a particular input, it gives a warning by default. These
+ warnings can be suppressed with <code>-Wno-hsa</code>. To give a few
+ examples, the HSA back end does not implement compilation of code
+ using function pointers, automatic allocation of variable sized
+ arrays, functions with variadic arguments as well as a number of
+ other less common programming constructs.</p>
+
+ <p>When compilation for HSA is enabled, the compiler attempts to
+ compile composite OpenMP constructs</p>
+ <blockquote><pre>
+#pragma omp target teams distribute parallel for</pre></blockquote>
+ <p>into parallel HSA GPU kernels.</p>
+ </li>
+ </ul>
<h3 id="x86">IA-32/x86-64</h3>
+ <ul>
+ <li>GCC now supports the Intel CPU named Skylake with AVX-512 extensions
+ through <code>-march=skylake-avx512</code>. The switch enables the following
+ ISA extensions: AVX-512F, AVX512VL, AVX-512CD, AVX-512BW, AVX-512DQ.
+ </li>
+ <li>
+ Support for new AMD instructions <code>monitorx</code> and
+ <code>mwaitx</code> has been added. This includes new intrinsic
+ and built-in support. It is enabled through option <code>-mmwaitx</code>.
+ The instructions <code>monitorx</code> and <code>mwaitx</code>
+ implement the same functionality as the old <code>monitor</code>
+ and <code>mwait</code> instructions. In addition <code>mwaitx</code>
+ adds a configurable timer. The timer value is received as third
+ argument and stored in register <code>%ebx</code>.
+ </li>
+ <li>
+ x86-64 targets now allow stack realignment from a word-aligned stack
+ pointer using the command-line option <code>-mstackrealign</code> or
+ <code>__attribute__ ((force_align_arg_pointer))</code>. This allows
+ functions compiled with a vector-aligned stack to be invoked from
+ objects that keep only word-alignment.
+ </li>
+ <li>
+ Support for address spaces <code>__seg_fs</code>, <code>__seg_gs</code>,
+ and <code>__seg_tls</code>. These can be used to access data via the
+ <code>%fs</code> and <code>%gs</code> segments without having to
+ resort to inline assembly.
+ Please refer to the <a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/Named-Address-Spaces.html#Named-Address-Spaces">
+ documentation</a> for usage instructions.
+ </li>
+ <li>
+ Support for AMD Zen (family 17h) processors is now available through
+ the <code>-march=znver1</code> and <code>-mtune=znver1</code> options.
+ </li>
+ </ul>
+<!-- <h3 id="mips">MIPS</h3> -->
+
+<h3 id="mep">MeP</h3>
<ul>
- <li>New ISA extensions support
- <a href="https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf">
- AVX-512{BW,DQ,VL,IFMA,VBMI}</a> of Intel's CPU
- codenamed Skylake Server was added to GCC. That includes inline
- assembly support, new intrinsics, and basic autovectorization. These
- new AVX-512 extensions are available via
- the following GCC switches: AVX-512 Vector Length EVEX feature:
- <code>-mavx512vl</code>, AVX-512 Byte and Word instructions:
- <code>-mavx512bw</code>, AVX-512 Dword and Qword instructions:
- <code>-mavx512dq</code>, AVX-512 FMA-52 instructions:
- <code>-mavx512ifma</code> and for AVX-512 Vector Bit Manipulation
- Instructions: <code>-mavx512vbmi</code>.</li>
- <li>New ISA extensions support
- <a href="https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf">
- Intel MPX</a> was added to GCC. This new extension is available via the
- <code>-mmpx</code> compiler switch. Intel MPX is a set of processor features which,
- with compiler, run-time library and OS support, brings increased robustness to
- software by run-time checking pointer references against their bounds.
- In GCC Intel MPX is supported by Pointer Bounds Checker and libmpx run-time
- libraries.</li>
- <li>The new <code>-mrecord-mcount</code> option for <code>-pg</code>
- generates a Linux kernel style table of pointers to
- <code>mcount</code> or <code>__fentry__</code> calls at the beginning
- of functions. The new <code>-mnop-mcount</code> option in addition
- also generates nops in place of the <code>__fentry__</code> or
- <code>mcount</code> call, so that a call per function can be later
- patched in. This can be used for low overhead tracing or hot code
- patching.</li>
- <li>The new <code>-malign-data</code> option controls how
- GCC aligns variables. <code>-malign-data=compat</code> uses
- increased alignment compatible with GCC 4.8 and earlier,
- <code>-malign-data=abi</code> uses alignment as specified by
- the psABI, and <code>-malign-data=cacheline</code> uses increased
- alignment to match the cache line size.
- <code>-malign-data=compat</code> is the default.</li>
- <li>The new <code>-mskip-rax-setup</code> option skips setting
- up the RAX register when SSE is disabled and there are no variable
- arguments passed in vector registers. This can be used to
- optimize the Linux kernel.</li>
+ <li><p>Support for the MeP (mep-elf) architecture has been
+ deprecated and will be removed in a future GCC release.</p>
+ </li>
</ul>
-<h3 id="mips">MIPS</h3>
+<h3 id="msp430">MSP430</h3>
<ul>
- <li>MIPS Releases 3 and 5 are now directly supported. Use the
- command-line options <code>-mips32r3</code>, <code>-mips64r3</code>,
- <code>-mips32r5</code> and <code>-mips64r5</code> to enable
- code-generation for these processors.</li>
- <li>The Imagination P5600 processor is now supported using the
- <code>-march=p5600</code> command-line option.</li>
- <li>The Cavium Octeon3 processor is now supported using the
- <code>-march=octeon3</code> command-line option.</li>
- <li>MIPS Release 6 is now supported using the <code>-mips32r6</code>
- and <code>-mips64r6</code> command-line options.</li>
- <li>The o32 ABI has been modified and extended. The o32 64-bit
- floating-point register support is now obsolete and has been removed.
- It has been replaced by three ABI extensions FPXX, FP64A, and FP64.
- The meaning of the <code>-mfp64</code> command-line option has
- changed. It is now used to enable the FP64A and FP64 ABI extensions.
- <ul>
- <li>The FPXX extension requires that code generated to access
- double-precision values use even-numbered registers. Code that
- adheres to this extension is link-compatible with all other o32
- double-precision ABI variants and will execute correctly in all
- hardware FPU modes. The command-line options <code>-mabi=32
- -mfpxx</code> can be used to enable this extension. MIPS II is
- the minimum processor required.</li>
- <li>The o32 FP64A extension requires that floating-point registers be
- 64-bit and odd-numbered single-precision registers are not
- allowed. Code that adheres to the o32 FP64A variant is
- link-compatible with all other o32 double-precision ABI variants.
- The command-line options <code>-mabi=32 -mfp64 -mno-odd-spreg
- </code> can be used to enable this extension. MIPS32R2 is the
- minimum processor required.</li>
- <li>The o32 FP64 extension also requires that floating-point registers
- be 64-bit, but permits the use of single-precision registers.
- Code that adheres to the o32 FP64 variant is link-compatible with
- o32 FPXX and o32 FP64A variants only, i.e. it is not compatible
- with the original o32 double-precision ABI. The command-line
- options <code>-mabi=32 -mfp64 -modd-spreg</code> can be used to
- enable this extension. MIPS32R2 is the minimum processor required.
- </li>
- </ul>
- The new ABI variants can be enabled by default using the configure time
- options <code>--with-fp-32=[32|xx|64]</code> and
- <code>--with(out)-odd-sp-reg-32</code>. It is strongly recommended that
- all vendors begin to set o32 FPXX as the default ABI. This will be
- required to run the generated code on MIPSR5 cores in conjunction with
- future MIPS SIMD (MSA) code and MIPSR6 cores.</li>
- <li>GCC will now pass all floating-point options to the assembler if GNU
- binutils 2.25 is used. As a result, any inline assembly code that
- uses hard-float instructions should be amended to include a
- <code>.set</code> directive to override the global assembler options
- when compiling for soft-float targets.</li>
+ <li><p>The MSP430 compiler now has the ability to automatically distribute code
+ and data between low memory (addresses below 64K) and high memory. This only
+ applies to parts that actually have both memory regions and only if the
+ linker script for the part has been specifically set up to support this
+ feature.</p>
+
+ <p>A new attribute of <code>either</code> can be applied to both functions
+ and data, and this tells the compiler to place the object into low memory
+ if there is room and into high memory otherwise. Two other new attributes
+ - <code>lower</code> and <code>upper</code> - can be used to explicitly
+ state that an object should be placed in the specified memory region. If
+ there is not enough left in that region the compilation will fail.</p>
+
+ <p>Two new command-line options - <code>-mcode-region=[lower|upper|either]</code>
+ and <code>-mdata-region=[lower|upper|either]</code> - can be used to tell
+ the compiler what to do with objects that do not have one of these new
+ attributes.</p></li>
</ul>
-<h3 id="nds32">NDS32</h3>
+<!-- <h3 id="nds32">NDS32</h3> -->
+
+<h3 id="powerpc">PowerPC / PowerPC64 / RS6000</h3>
<ul>
- <li>The variadic function ABI implementation is now compatible with
- past Andes toolchains where the caller uses registers to pass arguments
- and the callee is in charge of pushing them on stack.</li>
- <li>The options <code>-mforce-fp-as-gp</code>, <code>-mforbid-fp-as-gp</code>,
- and <code>-mex9</code> have been removed since they are not yet available
- in the nds32 port of GNU binutils.</li>
- <li>A new option <code>-mcmodel=[small|medium|large]</code> supports
- varied code models on code generation. The <code>-mgp-direct</code>
- option became meaningless and can be discarded.</li>
+ <li><p>PowerPC64 now supports IEEE 128-bit floating-point using the
+ __float128 data type. In GCC 6, this is NOT enabled by default,
+ but you can enable it with -mfloat128. The IEEE 128-bit
+ floating-point support requires the use of the VSX instruction
+ set. IEEE 128-bit floating-point values are passed and returned
+ as a single vector value. The software emulator for IEEE 128-bit
+ floating-point support is only built on PowerPC Linux systems
+ where the default cpu is at least power7. On future ISA 3.0
+ systems (power9 and later), you will be able to use the
+ -mfloat128-hardware option to use the ISA 3.0 instructions
+ that support IEEE 128-bit floating-point. An additional type
+ (__ibm128) has been added to refer to the IBM extended double
+ type that normally implements long double. This will allow
+ for a future transition to implementing long double with IEEE
+ 128-bit floating-point.</p></li>
+ <li><p>Basic support has been added for POWER9 hardware that will use the
+ recently published OpenPOWER ISA 3.0 instructions. The following
+ new switches are available:</p>
+ <ul>
+ <li><p><u>-mcpu=power9</u>: Implement all of the ISA 3.0
+ instructions supported by the compiler.</p></li>
+ <li><p><u>-mtune=power9</u>: In the future, apply tuning for
+ POWER9 systems. Currently, POWER8 tunings are used.</p></li>
+ <li><p><u>-mmodulo</u>: Generate code using the ISA 3.0
+ integer instructions (modulus, count trailing zeros, array
+ index support, integer multiply/add).</p></li>
+ <li><p><u>-mpower9-fusion</u>: Generate code to suitably fuse
+ instruction sequences for a POWER9 system.</p></li>
+ <li><p><u>-mpower9-dform</u>: Generate code to use the new D-form
+ (register +offset) memory instructions for the vector
+ registers.</p></li>
+ <li><p><u>-mpower9-vector</u>: Generate code using the new ISA
+ 3.0 vector (VSX or Altivec) instructions.</p></li>
+ <li><p><u>-mpower9-minmax</u>: Reserved for future development.
+ </p></li>
+ <li><p><u>-mtoc-fusion</u>: Keep TOC entries together to provide
+ more fusion opportunities.</p></li>
+ </ul></li>
+ <li><p>New constraints have been added to support IEEE 128-bit
+ floating-point and ISA 3.0 instructions:</p>
+ <ul>
+ <li><p><u>wb</u>: Altivec register if -mpower9-dform is
+ enabled.</p></li>
+ <li><p><u>we</u>: VSX register if -mpower9-vector is enabled
+ for 64-bit code generation.</p></li>
+ <li><p><u>wo</u>: VSX register if -mpower9-vector is
+ enabled.</p></li>
+ <li><p><u>wp</u>: Reserved for future use if long double
+ is implemented with IEEE 128-bit floating-point instead
+ of IBM extended double.</p></li>
+ <li><p><u>wq</u>: VSX register if -mfloat128 is enabled.</p></li>
+ <li><p><u>wF</u>: Memory operand suitable for POWER9 fusion
+ load/store.</p></li>
+ <li><p><u>wG</u>: Memory operand suitable for TOC fusion memory
+ references.</p></li>
+ <li><p><u>wL</u>: Integer constant identifying the element
+ number mfvsrld accesses within a vector.</p></li>
+ </ul></li>
+ <li><p>Support has been added for __builtin_cpu_is () and
+ __builtin_cpu_supports (), allowing for very fast access to
+ AT_PLATFORM, AT_HWCAP, and AT_HWCAP2 values. This requires
+ use of glibc 2.23 or later.</p></li>
+ <li><p>All hardware transactional memory builtins now correctly
+ behave as memory barriers. Programmers can use #ifdef __TM_FENCE__
+ to determine whether their "old" compiler treats the builtins
+ as barriers.</p></li>
+ <li><p>Split-stack support has been added for gccgo on PowerPC64
+ for both big- and little-endian (but NOT for 32-bit). The gold
+ linker from at least binutils 2.25.1 must be available in the PATH
+ when configuring and building gccgo to enable split stack. (The
+ requirement for binutils 2.25.1 applies to PowerPC64 only.) The
+ split-stack feature allows a small initial stack size to be
+ allocated for each goroutine, which increases as needed.</p></li>
+ <li><p>GCC on PowerPC now supports the standard lround function.</p></li>
+ <li><p>A new configuration option -<code>--with-advance-toolchain=at</code>
+ was added for PowerPC 64-bit GNU/Linux systems to use the header files, library
+ files, and the dynamic linker from a specific Advance Toolchain release
+ instead of the default versions that are provided by the GNU/Linux
+ distribution. In general, this option is intended for the developers of
+ GCC, and it is not intended for general use.</p></li>
+ <li><p>The "q", "S", "T", and "t" asm-constraints have been
+ removed.</p></li>
+ <li><p>The "b", "B", "m", "M", and "W" format modifiers have
+ been removed.</p></li>
</ul>
-<h3 id="rx">RX</h3>
+<h3 id="s390">S/390, System z, IBM z Systems</h3>
<ul>
- <li>A new command line option <code>-mno-allow-string-insns</code> can be
- used to disable the generation of the <code>SCMPU</code>, <code>SMOVU</code>,
- <code>SMOVB</code>, <code>SMOVF</code>, <code>SUNTIL</code>, <code>SWHILE</code>
- and <code>RMPA</code> instructions. An erratum released by Renesas shows
- that it is unsafe to use these instructions on addresses within the I/O
- space of the processor. The new option can be used when the programmer is
- concerned that the I/O space might be accessed. The default is still to
- enable these instructions.</li>
+ <li>Support for the IBM z13 processor has been added. When using
+ the <code>-march=z13</code> option, the compiler will generate
+ code making use of the new instructions and registers introduced
+ with the vector extension facility. The <code>-mtune=z13</code>
+ option enables z13 specific instruction scheduling without
+ making use of new instructions.<br/>
+
+ Compiling code with <code>-march=z13</code> reduces the default
+ alignment of vector types bigger than 8 bytes to 8. This is an
+ ABI change and care must be taken when linking modules compiled
+ with different arch levels which interchange variables
+ containing vector type values. For newly compiled code the GNU
+ linker will emit a warning.</li>
+
+ <li>The <code>-mzvector</code> option enables a C/C++ language
+ extension. This extension provides a new
+ keyword <code>vector</code> which can be used to define vector
+ type variables. (Note: This is not available when
+ enforcing strict standard compliance
+ e.g. with <code>-std=c99</code>. Either enable GNU extensions
+ with e.g. <code>-std=gnu99</code> or use
+ <code>__vector</code> instead of <code>vector</code>.)<br/>
+
+ Additionally a set of overloaded builtins is provided which is
+ partially compatible to the PowerPC Altivec builtins. In order
+ to make use of these builtins the <code>vecintrin.h</code>
+ header file needs to be included.</li>
+
+ <li>The new command line options <code>-march=native</code>,
+ and <code>-mtune=native</code> are now available on native IBM
+ z Systems. Specifying these options will cause GCC to
+ auto-detect the host CPU and rewrite these options to the
+ optimal setting for that system. If GCC is unable to detect
+ the host CPU these options have no effect.</li>
+
+ <li>The IBM z Systems port now supports target attributes and
+ pragmas. Please refer to the
+ <a href="https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/S_002f390-Function-Attributes.html#S_002f390-Function-Attributes">
+ documentation</a> for details of available attributes and
+ pragmas as well as usage instructions.
+ </li>
+
+ <li><code>-fsplit-stack</code> is now supported as part of the IBM
+ z Systems port. This feature requires a recent gold linker to
+ be used.</li>
+
+ <li>Support for the <code>g5</code> and <code>g6
+ -march=/-mtune=</code> CPU level switches has been deprecated
+ and will be removed in a future GCC release. <code>-m31</code>
+ from now on defaults to <code>-march=z900</code> if not
+ specified otherwise. <code>-march=native</code> on a g5/g6
+ machine will default to <code>-march=z900</code>.</li>
</ul>
+<!-- <h3 id="rx">RX</h3> -->
+
<h3 id="sh">SH</h3>
<ul>
- <li>The compiler will now pass the appropriate <code>--isa=</code> option
- to the assembler.</li>
-
- <li>The default handling for the <code>GBR</code> has been changed from
- call clobbered to call preserved. The old behavior can be reinstated by
- specifying the option <code>-fcall-used-gbr</code>.</li>
-
- <li>Support for the SH4A <code>fpchg</code> instruction has been added which
- will be utilized when switching between single and double precision FPU
- modes.</li>
-
- <li>The compiler no longer uses the <code>__fpscr_values</code> array for
- switching between single and double FPU precision modes on non-SH4A targets.
- Instead mode switching will now be performed by storing, modifying and
- reloading the <code>FPSCR</code>, so that other <code>FPSCR</code> bits are
- preserved across mode switches. The <code>__fpscr_values</code> array that
- is defined in libgcc is still present for backwards compatibility, but it
- will not be referenced by compiler generated code anymore.</li>
-
- <li>New builtin functions <code>__builtin_sh_get_fpscr</code> and
- <code>__builtin_sh_set_fpscr</code> have been added. The
- <code>__builtin_sh_set_fpscr</code> function will mask the specified bits
- in such a way that the <code>SZ</code>, <code>PR</code> and <code>FR</code>
- mode bits will be preserved, while changing the other bits. These new
- functions do not reference the <code>__fpscr_values</code> array. The old
- functions <code>__set_fpscr</code> and <code>__get_fpscr</code> in libgcc
- which access the <code>__fpscr_values</code> array are still present for
- backwards compatibility, but their usage is highly discouraged.</li>
-
- <li>Some improvements to code generated for <code>__atomic</code> built-in
- functions.</li>
-
- <li>When compiling for SH2E the compiler will no longer force the usage of
- delay slots for conditional branch instructions <code>bt</code> and
- <code>bf</code>. The old behavior can be reinstated (e.g. to work around a
- hardware bug in the original SH7055) by specifying the new option
- <code>-mcbranch-force-delay-slot</code>.</li>
+ <li>Support for SH5 / SH64 has been declared obsolete and will be removed
+ in future releases.</li>
+
+ <li>Support for the FDPIC ABI has been added. It can be enabled using the
+ new <code>-mfdpic</code> target option and <code>--enable-fdpic</code>
+ configure option.</li>
+ </ul>
+
+<h3 id="sparc">SPARC</h3>
+ <ul>
+ <li>An ABI bug has been fixed in 64-bit mode. Unfortunately, this change
+ will break binary compatibility with earlier releases for code it affects,
+ but this should be pretty rare in practice. The conditions are: a 16-byte
+ structure containing a <code>double</code> or a 8-byte vector in the second
+ half is passed to a subprogram in slot #15, for example as 16th parameter
+ if the first 15 ones have at most 8 bytes. The <code>double</code> or
+ vector was wrongly passed in floating-point register <code>%d32</code>
+ in lieu of on the stack as per the SPARC calling conventions.</li>
</ul>
+<!-- .................................................................. -->
<h2 id="os">Operating Systems</h2>
- <h3 id="dragonfly">DragonFly BSD</h3>
+<!-- <h3 id="dragonfly">DragonFly BSD</h3> -->
+
+<!-- <h3 id="freebsd">FreeBSD</h3> -->
+<h3 id="linux">Linux</h3>
<ul>
- <li>GCC now supports the DragonFly BSD operating system.</li>
+ <li>Support for the <a href="http://www.musl-libc.org">musl C library</a>
+ was added for the AArch64, ARM, MicroBlaze, MIPS, MIPS64, PowerPC,
+ PowerPC64, SH, i386, x32 and x86_64 targets. It can be selected using the
+ new <code>-mmusl</code> option in case musl is not the default libc. GCC
+ defaults to musl libc if it is built with a target triplet matching the
+ <code>*-linux-musl*</code> pattern.</li>
</ul>
- <h3 id="freebsd">FreeBSD</h3>
-
+<h3 id="rtems">RTEMS</h3>
<ul>
- <li>GCC now supports the FreeBSD operating system for the arm port
- through the <code>arm*-*-freebsd*</code> target triplets.</li>
+ <li>The RTEMS thread model implementation changed. Mutexes now
+ use self-contained objects defined in Newlib <sys/lock.h>
+ instead of Classic API semaphores. The keys for thread specific data and
+ the <code>once</code> function are directly defined via <pthread.h>.
+ Self-contained condition variables are provided via Newlib
+ <sys/lock.h>. The RTEMS thread model also supports C++11
+ threads.</li>
+
+ <li>OpenMP support now uses self-contained objects provided by Newlib
+ <sys/lock.h> and offers a significantly better performance compared
+ to the POSIX configuration of <code>libgomp</code>. It is possible to
+ configure thread pools for each scheduler instance via the environment
+ variable <code>GOMP_RTEMS_THREAD_POOLS</code>.</li>
</ul>
- <h3 id="vxmils">VxWorks MILS</h3>
+<h3 id="aix">AIX</h3>
+ <ul>
+ <li>DWARF debugging support for AIX 7.1 has been enabled as an optional
+ debugging format. A more recent Technology Level (TL) and GCC built
+ with that level are required for full exploitation of DWARF debugging
+ capabilities.</li>
+ </ul>
+<h3 id="solaris">Solaris</h3>
<ul>
- <li>GCC now supports the MILS (Multiple Independent Levels
- of Security) variant of WindRiver's VxWorks operating system
- for PowerPC targets.</li>
+ <li>Solaris 12 is now fully supported. Minimal support had already
+ been present in GCC 5.3.</li>
+ <li>Solaris 12 provides a full set of startup files (<code>crt1.o</code>,
+ <code>crti.o</code>, <code>crtn.o</code>), which GCC now prefers over
+ its own ones.</li>
+ <li>Position independent executables (PIE) are now supported on
+ Solaris 12.</li>
+ <li>Constructor priority is now supported on Solaris 12 with the system
+ linker.</li>
+ <li><code>libvtv</code> has been ported to Solaris 11 and up.</li>
</ul>
-<!-- h2>Documentation improvements</h2-->
-<h2>Other significant improvements</h2>
- <h3 id="gcc-ar"></h3>
+<h3 id="windows">Windows</h3>
<ul>
- <li>The <code>gcc-ar</code>, <code>gcc-nm</code>, <code>gcc-ranlib</code>
- wrappers now understand a <code>-B</code> option to set the compiler
- to use.</li>
+ <li>The option <code>-mstackrealign</code> is now automatically activated
+ in 32-bit mode whenever the use of SSE instructions is requested.</li>
</ul>
- <h3 id="driver"></h3>
+<!-- <h3 id="vxmils">VxWorks MILS</h3> -->
+
+
+<!-- .................................................................. -->
+<!-- <h2>Documentation improvements</h2> -->
+
+
+<!-- .................................................................. -->
+<h2>Other significant improvements</h2>
+
<ul>
- <li>When the new command-line option <code>-freport-bug</code> is
- used, GCC automatically generates a developer-friendly reproducer
- whenever an internal compiler error is encountered.</li>
+ <li>The <code>gcc</code> and <code>g++</code> driver programs will now
+ provide suggestions for misspelled command line options.
+<blockquote><pre>
+$ gcc -static-libfortran test.f95
+gcc: <span class="boldred">error:</span> unrecognized command line option <b>'-static-libfortran'</b>; did you mean <b>'-static-libgfortran'</b>?
+</pre></blockquote></li>
+ <li>The <code>--enable-default-pie</code> configure option enables
+ generation of PIE by default.</li>
</ul>
+
<!-- ==================================================================== -->
<div class="copyright">
-<address style="margin-top:0;">For questions related to the use of GCC,
+<address>For questions related to the use of GCC,
please consult these web pages and the
<a href="https://gcc.gnu.org/onlinedocs/">GCC manuals</a>. If that fails,
the <a href="mailto:gcc-help at gcc.gnu.org">gcc-help at gcc.gnu.org</a>
@@ -956,9 +828,9 @@ have public archives.
Verbatim copying and distribution of this entire article is
permitted in any medium, provided this notice is preserved.</p>
-<p style="margin-bottom:0;">These pages are
+<p>These pages are
<a href="https://gcc.gnu.org/about.html">maintained by the GCC team</a>.
-Last modified 2015-04-22<!-- IGNORE DIFF
+Last modified 2016-04-27<!-- IGNORE DIFF
--><a href="http://validator.w3.org/check/referer">.</a></p>
</div>
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