[SCM] WebKit Debian packaging branch, webkit-1.2, updated. upstream/1.1.90-6072-g9a69373

[barraclough at apple.com]

The following commit has been merged in the webkit-1.2 branch:
commit 66829dc78cd3d8010a41c1c5327093b36ee2a092
Author: barraclough at apple.com <barraclough at apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Date:   Thu Nov 5 05:02:09 2009 +0000

    https://bugs.webkit.org/show_bug.cgi?id=31151
    Fix branchDouble behaviour on ARM THUMB2 JIT.
    
    Patch by Gavin Barraclough <barraclough at apple.com> on 2009-11-04
    Reviewed by Oliver Hunt.
    
    The ARMv7 JIT is currently using ARMv7Assembler::ConditionEQ to branch
    for DoubleEqualOrUnordered, however this is incorrect – ConditionEQ won't
    branch on unordered operands.  Similarly, DoubleLessThanOrUnordered &
    DoubleLessThanOrEqualOrUnordered use ARMv7Assembler::ConditionLO &
    ARMv7Assembler::ConditionLS, whereas they should be using
    ARMv7Assembler::ConditionLT & ARMv7Assembler::ConditionLE.
    
    Fix these, and fill out the missing DoubleConditions.
    
    * assembler/MacroAssemblerARMv7.h:
    (JSC::MacroAssemblerARMv7::):
    (JSC::MacroAssemblerARMv7::branchDouble):
    
    
    
    git-svn-id: http://svn.webkit.org/repository/webkit/trunk@50541 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/JavaScriptCore/ChangeLog b/JavaScriptCore/ChangeLog
index 9420b3e..f1292fb 100644
--- a/JavaScriptCore/ChangeLog
+++ b/JavaScriptCore/ChangeLog
@@ -1,5 +1,25 @@
 2009-11-04  Gavin Barraclough  <barraclough at apple.com>
 
+        Reviewed by Oliver Hunt.
+
+        https://bugs.webkit.org/show_bug.cgi?id=31151
+        Fix branchDouble behaviour on ARM THUMB2 JIT.
+
+        The ARMv7 JIT is currently using ARMv7Assembler::ConditionEQ to branch
+        for DoubleEqualOrUnordered, however this is incorrect – ConditionEQ won't
+        branch on unordered operands.  Similarly, DoubleLessThanOrUnordered &
+        DoubleLessThanOrEqualOrUnordered use ARMv7Assembler::ConditionLO &
+        ARMv7Assembler::ConditionLS, whereas they should be using
+        ARMv7Assembler::ConditionLT & ARMv7Assembler::ConditionLE.
+
+        Fix these, and fill out the missing DoubleConditions.
+
+        * assembler/MacroAssemblerARMv7.h:
+        (JSC::MacroAssemblerARMv7::):
+        (JSC::MacroAssemblerARMv7::branchDouble):
+
+2009-11-04  Gavin Barraclough  <barraclough at apple.com>
+
         Rubber Stamped by Oliver Hunt.
 
         Enable native call optimizations on ARMv7.  (Existing ARM_TRADITIONAL
diff --git a/JavaScriptCore/assembler/MacroAssemblerARMv7.h b/JavaScriptCore/assembler/MacroAssemblerARMv7.h
index 26983bc..ab117d4 100644
--- a/JavaScriptCore/assembler/MacroAssemblerARMv7.h
+++ b/JavaScriptCore/assembler/MacroAssemblerARMv7.h
@@ -93,13 +93,21 @@ public:
         Zero = ARMv7Assembler::ConditionEQ,
         NonZero = ARMv7Assembler::ConditionNE
     };
-
     enum DoubleCondition {
-        DoubleEqualOrUnordered = ARMv7Assembler::ConditionEQ,
+        // These conditions will only evaluate to true if the comparison is ordered - i.e. neither operand is NaN.
+        DoubleEqual = ARMv7Assembler::ConditionEQ,
+        DoubleNotEqual = ARMv7Assembler::ConditionVC, // Not the right flag! check for this & handle differently.
         DoubleGreaterThan = ARMv7Assembler::ConditionGT,
         DoubleGreaterThanOrEqual = ARMv7Assembler::ConditionGE,
-        DoubleLessThanOrUnordered = ARMv7Assembler::ConditionLO,
-        DoubleLessThanOrEqualOrUnordered = ARMv7Assembler::ConditionLS,
+        DoubleLessThan = ARMv7Assembler::ConditionLO,
+        DoubleLessThanOrEqual = ARMv7Assembler::ConditionLS,
+        // If either operand is NaN, these conditions always evaluate to true.
+        DoubleEqualOrUnordered = ARMv7Assembler::ConditionVS, // Not the right flag! check for this & handle differently.
+        DoubleNotEqualOrUnordered = ARMv7Assembler::ConditionNE,
+        DoubleGreaterThanOrUnordered = ARMv7Assembler::ConditionHI,
+        DoubleGreaterThanOrEqualOrUnordered = ARMv7Assembler::ConditionHS,
+        DoubleLessThanOrUnordered = ARMv7Assembler::ConditionLT,
+        DoubleLessThanOrEqualOrUnordered = ARMv7Assembler::ConditionLE,
     };
 
     static const RegisterID stackPointerRegister = ARMRegisters::sp;
@@ -531,6 +539,23 @@ public:
     {
         m_assembler.vcmp_F64(left, right);
         m_assembler.vmrs_APSR_nzcv_FPSCR();
+
+        if (cond == DoubleNotEqual) {
+            // ConditionNE jumps if NotEqual *or* unordered - force the unordered cases not to jump.
+            Jump unordered = makeBranch(ARMv7Assembler::ConditionVS);
+            Jump result = makeBranch(ARMv7Assembler::ConditionNE);
+            unordered.link(this);
+            return result;
+        }
+        if (cond == DoubleEqualOrUnordered) {
+            Jump unordered = makeBranch(ARMv7Assembler::ConditionVS);
+            Jump notEqual = makeBranch(ARMv7Assembler::ConditionNE);
+            unordered.link(this);
+            // We get here if either unordered, or equal.
+            Jump result = makeJump();
+            notEqual.link(this);
+            return result;
+        }
         return makeBranch(cond);
     }
 

-- 
WebKit Debian packaging