[pkg-mad-maintainers] Bug#881283: Bug#881283: libmad0: produces different results on s390x/arm64/...

[Kurt Roeckx]

On Thu, Nov 09, 2017 at 05:23:56PM +0100, IOhannes m zmoelnig wrote:
> Package: libmad0
> Version: 0.15.1b-8.1
> Severity: important
> 
> Dear Maintainer,
> 
> TL;DR: it seems that libmad is not really usable on s390x.
> 
> i'm currently trying to find out why sonic-visualiser_3.0.3-1 fails to build
> successfully on the s390x and arm64 architectures.
> The problem is a failing test when decoding mp3 files.
> The test runs fine on most release architectures, but fails on
> - arm64
> - s390x
> - alpha
> - hppa
> - m68k
> - sh4

I'd like to point to this part of configure.ac:
AC_MSG_CHECKING(for architecture-specific fixed-point math routines)
AC_ARG_ENABLE(fpm, AC_HELP_STRING([--enable-fpm=ARCH],
                   [use ARCH-specific fixed-point math routines
                    (one of: intel, arm, mips, sparc, ppc, 64bit, default)]),
[
    case "$enableval" in
        yes)                             ;;
        no|default|approx) FPM="DEFAULT" ;;
        intel|i?86)        FPM="INTEL"   ;;
        arm)               FPM="ARM"     ;;
        mips)              FPM="MIPS"    ;;
        sparc)             FPM="SPARC"   ;;
        ppc|powerpc)       FPM="PPC"     ;;
        64bit)             FPM="64BIT"   ;;
        float)             FPM="FLOAT"   ;;
        *)
            AC_MSG_RESULT(failed)
            AC_MSG_ERROR([bad --enable-fpm option])
            ;;
    esac
])

if test -z "$FPM" && test "$GCC" = yes
then
    case "$host" in
        i?86-*)     FPM="INTEL"  ;;
        x86_64*)    FPM="64BIT"  ;;
        arm*-*)     FPM="ARM"    ;;
        mips*-*)    FPM="MIPS"   ;;
        sparc*-*)   FPM="SPARC"  ;;
        powerpc*-*) FPM="PPC"    ;;
        # FIXME: need to test for 64-bit long long...
    esac
fi

AC_MSG_RESULT(${FPM=DEFAULT})

if test "$FPM" = "DEFAULT"
then
    AC_MSG_WARN([default fixed-point math will yield limited accuracy])
fi

You should probably set it to 64BIT, which is what I did for amd64.
The others are assembler implementations.


Kurt