[Ffmpeg-devel] [PATCH] minor H.264 asm optimization

Reimar Döffinger Reimar.Doeffinger
Thu Feb 22 12:54:05 CET 2007

On Thu, Feb 22, 2007 at 11:16:27AM -0000, M?ns Rullg?rd wrote:
> Reimar D?ffinger said:
> > attached patch reduces code size quite a lot for me, since my gcc (4.1.2)
> > stupidly does loop unrolling.
> > Not that this was tested only quickly, only on AMD64 and not properly
> > benchmarked.
> Loop unrolling sometimes makes code faster, sometimes not.  You really should
> benchmark this.

No question, though benchmarking only on my PC is not sufficient anyway.
Problem with benchmarking is, I am too stupid to get
START_TIMER/STOP_TIMER to print anything, at least when used within that
code (and yes, the code is executed).
Only values I have are for mplayer -nosound -benchmark -vo null:
3 runs with old code:
BENCHMARKs: VC:   9.101s VO:   0.003s A:   0.000s Sys:   0.420s = 9.525s
BENCHMARKs: VC:   9.258s VO:   0.004s A:   0.000s Sys:   0.438s = 9.699s
BENCHMARKs: VC:   9.089s VO:   0.003s A:   0.000s Sys:   0.420s = 9.513s

3 runs with new code:
BENCHMARKs: VC:   9.184s VO:   0.004s A:   0.000s Sys:   0.419s = 9.607s
BENCHMARKs: VC:   9.066s VO:   0.003s A:   0.000s Sys:   0.420s = 9.489s
BENCHMARKs: VC:   9.118s VO:   0.004s A:   0.000s Sys:   0.414s = 9.536s

Hardly anything you could call significant...

Reimar D?ffinger

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