[Ffmpeg-devel] Re: [PATCH] fix snow x86 SIMD

Martin von Gagern Martin.vGagern
Thu Aug 10 16:58:38 CEST 2006

Michael Niedermayer wrote:
> maybe you could just make ebx -> "r"?

Good suggestion. This seems to work.

The attached patch passed all regression tests for gcc 2.95.3, 3.4.6 and
4.1.1, both with and without --disable-static, --enable-shared and
--extra-cflags="-DPIC -fPIC -fomit-frame-pointer". At least as long as I
did not have multiple server tests running in parallel. ;-)

> * check that gcc assembled the code correctly, ive seen cases where gcc
>   silently violated some constrains

Indeed, it's been using ebp for input %2 as well, although that register
is clearly on the clobber list. I'll try to find a gcc bug report on
this or file a new one if needed. But first I'll have to build a smaller
test case reproducing this.

> * look at sb->line which is where edx comes from i think

REG_D is edi, not edx, but never mind that.

 Martin von Gagern
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