[Ffmpeg-devel] [PATCH] fix mpegaudiodec on ARM and benchmark

Siarhei Siamashka siarhei.siamashka
Tue Sep 12 23:02:40 CEST 2006

On Tuesday 12 September 2006 22:15, you wrote:


> By the way, there seems to be a huge performance regression on x86 for
> ffmp3 decoder when switching from gcc 3.4.6 to gcc 4.1.1 (time for
> decoding grows roughly from 3.5 seconds to about 5 seconds in my tests).

Please ignore this information. It was true for ffmpeg included as part of
MPlayer 1.0pre8. 

The latest SVN version of ffmpeg is actually faster with gcc 4.1.1 on ffmp3
decoder. But disabling asm optimizations in mpegaudiodec.c, you can 
reproduce this performance regression quite easily.

gcc 4.1.1 with asm: 3.0 seconds
gcc 4.1.1 without asm: 5.8 seconds

That's not very relevant for mp3 decoding now, but obviously gcc 4.1.1 can
produce worse code than older versions sometimes.

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