[FFmpeg-devel] [PATCH] update doc/optimization.txt

Michael Niedermayer michaelni
Tue Sep 21 16:11:45 CEST 2010


On Tue, Sep 21, 2010 at 06:58:44AM -0700, Jason Garrett-Glaser wrote:
> On Tue, Sep 21, 2010 at 6:30 AM, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Tue, Sep 21, 2010 at 05:37:40AM -0700, Jason Garrett-Glaser wrote:
> >> > interresting strawman argument
> >> > noone was talking about cases that cannot easily be done in inline asm
> >> > not that calling from inline would be impossible or anything but i surely
> >> > agree that for these 0.1% of asm yasm is likely the better choice
> >>
> >> You mean this 99%. ?It's only 0.1% because you don't think about
> >> optimizations that can't be done under your current system.
> >
> > please elaborate on what other optimizations are possible in yasm that cannot
> > be done in inline asm.
> 
> Basically all optimizations that involve sharing code between
> functions to reduce code size.  See common/x86/cabac-a.asm for an
> example in x264, where all of x264's CABAC functions fit in under 256
> bytes combined.
> 
> Most functions can benefit from such optimizations, and saving 50% on
> code size is more valuable than any hypothetical function call
> overhead.

i see your point and agree that this is a case where an extrenal assembler
should be used but i dont agree that this affects most functions.

also id like to repeat what i said earlier, that iam all in favor of yasm
when an optimization needs it

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I know you won't believe me, but the highest form of Human Excellence is
to question oneself and others. -- Socrates
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