[Ffmpeg-devel] [PATCH] lowres chroma bug

[Michael Niedermayer]

Hi

On Tue, Feb 06, 2007 at 10:46:41PM -0800, Trent Piepho wrote:
> On Wed, 7 Feb 2007, Oleg Metelitsa wrote:
> > MN> no because it slows the non lowres code down
> >
> > Please find a patch below and a short explanation why the "lowres
> > chroma bug" appears.
> >
> >              H264_CHROMA_OP4(%0, %%mm1, %%mm3)
> > -            "movd %%mm1, %0\n\t"
> > -            : "=m" (dst[0]) : "m" (ff_pw_32));
> > +            "movd %%mm1, %%edx\n\t"
> > +            "mov %%dx, %0\n\t"
> > +            : "=m" (dst[0]) : "m" (ff_pw_32): "%edx");
> >          dst += stride;
> >      }
> 
> Instead of hardcoding the scratch register, it's better to let gcc choose a
> register.  Like this:

last time i compared hardcoded registers with gcc-choosen ones, the later
where slower (that was in cabac.h in case you want to proof me wrong, id
be happy if we could get rid of the hardcoded registers there ...)


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The worst form of inequality is to try to make unequal things equal.
-- Aristotle
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