[FFmpeg-devel] [PATCH] Altivec version of h264_idct_add

[Michael Niedermayer]

Hi

On Fri, Jun 01, 2007 at 06:52:57PM -0400, David Conrad wrote:
> Hi,
> 
> This is an updated version of ff_h264_idct_add_altivec, based on a  
> patch by Mauricio Alvarez [1]. It's 1.9 times faster than the scalar  
> version on my G4. Regression tests pass except for seektest, which is  
> currently broken for me with vanilla SVN (should it work?)
> 
> 170 dezicycles in ff_h264_idct_add_altivec, 1 runs, 0 skips
> 150 dezicycles in ff_h264_idct_add_altivec, 2 runs, 0 skips
> 287 dezicycles in ff_h264_idct_add_altivec, 4 runs, 0 skips
> 203 dezicycles in ff_h264_idct_add_altivec, 8 runs, 0 skips
> 131 dezicycles in ff_h264_idct_add_altivec, 16 runs, 0 skips
> 79 dezicycles in ff_h264_idct_add_altivec, 32 runs, 0 skips
> 53 dezicycles in ff_h264_idct_add_altivec, 64 runs, 0 skips
> 33 dezicycles in ff_h264_idct_add_altivec, 128 runs, 0 skips
> 23 dezicycles in ff_h264_idct_add_altivec, 256 runs, 0 skips
> 18 dezicycles in ff_h264_idct_add_altivec, 512 runs, 0 skips
> 15 dezicycles in ff_h264_idct_add_altivec, 1024 runs, 0 skips
> 14 dezicycles in ff_h264_idct_add_altivec, 2048 runs, 0 skips
> 14 dezicycles in ff_h264_idct_add_altivec, 4096 runs, 0 skips
> 13 dezicycles in ff_h264_idct_add_altivec, 8192 runs, 0 skips
> 14 dezicycles in ff_h264_idct_add_altivec, 16384 runs, 0 skips
> 14 dezicycles in ff_h264_idct_add_altivec, 32768 runs, 0 skips
> 14 dezicycles in ff_h264_idct_add_altivec, 65536 runs, 0 skips

where where the START/STOP_TIMER placed?
this doesnt look correct the idct isnt being executed in 1.4 cpu cycles

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

Dictatorship naturally arises out of democracy, and the most aggravated
form of tyranny and slavery out of the most extreme liberty. -- Plato
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