[Ffmpeg-devel] [RFC] smallcpy for h264

Luca Barbato lu_zero
Sat Oct 7 14:18:52 CEST 2006

Michael Niedermayer wrote:
> but before i will agree to this i want
> 1. to know why we spend a significant time doing small memcpys

Loren do you have time to have a look on it? The on x86simd codepath has
many of them...

> 2. why ppc doesnt inline memcpy like x86 does

inlined memcpy are triggered with -O3 iirc, so having them doesn't help
speed at all (see the threads about avoiding -O3 to get better speed)
I'll dig glibc to see if we have inlined variants available.

> furthermore these aligment related changes must be split,reviewed
> and applied before any benchmarking makes sense (= your benchmark
> of missaliged arrays with memcpy vs. your code with aligned arrays
> might show more the speed difference of alignment and less that
> of the actual code)

please check the attached code.



Luca Barbato

Gentoo/linux Gentoo/PPC

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