[FFmpeg-devel] [HACK] 50% faster H.264 decoding

Luca Barbato lu_zero
Sun Aug 22 21:42:49 CEST 2010

On 08/22/2010 04:58 AM, Jason Garrett-Glaser wrote:
>> Keep in mind that some compilers (like open64) might support inline asm
>> and cannot do link time optimizations on yasm generated binaries...
> Why would I want the compiler doing link-time "optimization" on my
> asm?  I would consider that inability a benefit.

It cannot perform link time optimization at all if you are trying to
link something foreign apparently, that is an annoying limitation but
that is. By your reasoning you would consider hand writing everything in
asm since you would get it right better than a compiler.

Is still the whole asm vs intrinsics again. I do agree that using asm
_now_ on platforms with depressing implementations (hi sse and neon
intrinsics) is the only safe way.

Still you end up with code that wishfully would work fine across
different cpus only because the scheduling of those instructions might
not had changed a lot yet.

ASM optimizations are single target and could be outright wrong when
recycled (e.g x86 vs amd64).

lu - summer sales on trollfood today!


Luca Barbato

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