[FFmpeg-cvslog] r20739 - in trunk/libavcodec: apedec.c dsputil.c dsputil.h ppc/int_altivec.c x86/dsputil_mmx.c x86/dsputil_yasm.asm

[Loren Merritt]

On Mon, 7 Dec 2009, Ramiro Polla wrote:
> On Sun, Dec 6, 2009 at 5:02 PM, Reimar D?ffinger wrote:
>>
>> In addition, gcc 4.2.4 MinGW and Cygwin ?builds seem to decode incorrectly:
>> http://fate.multimedia.cx/index.php?build_record=144294
>>
>> Though consistently between them:
>> http://fate.multimedia.cx/index.php?test_result=33060104
>> http://fate.multimedia.cx/index.php?test_result=33055764
>
> Also reproducible on Ubuntu Linux 9.04 (gcc: Ubuntu 4.3.3-5ubuntu4,
> yasm: 0.7.1.2093) compiling for 32-bit (--cc='ccache gcc -m32'
> --arch=i686 --cpu=i686), forcing ff_scalarproduct_and_madd_int16_sse2
> to be used on a q6600.

So when fate says "works on x86_32/Windows/MinGW/gcc-3.4.6, fails on 
x86_32/Windows/MinGW/gcc-4.2.4", that could be because those two tests 
where run on different computers with different simd capabilities and thus 
using different codepaths.
It's good to test everything, but it can be misleading if I start the 
debugging process on the assumption that it's the type of bug that gets 
exposed by differing compiler versions.

--Loren Merritt