[FFmpeg-devel] [PATCH] VC-1 MMX DSP functions

[Reimar Döffinger]

Hello,
On Tue, Oct 02, 2007 at 11:19:42PM +0200, Michael Niedermayer wrote:
[...]
> > +        ASMALIGN(3)
> > +        "1:                                \n\t"
> 
> how much speed is gained by the align?

Inconclusive in my tests on AMD64 on a 64 bit OS:
without:
3012 dezicycles in vc1_put_ver_16b_shift2_mmx, 1048397 runs, 179 skips
1249 dezicycles in vc1_put_hor_16b_shift2_mmx, 1048505 runs, 71 skips

3011 dezicycles in vc1_put_ver_16b_shift2_mmx, 1048397 runs, 179 skips
1232 dezicycles in vc1_put_hor_16b_shift2_mmx, 1048517 runs, 59 skips

3011 dezicycles in vc1_put_ver_16b_shift2_mmx, 1048514 runs, 62 skips
1232 dezicycles in vc1_put_hor_16b_shift2_mmx, 1048548 runs, 28 skips

with:
3038 dezicycles in vc1_put_ver_16b_shift2_mmx, 1048340 runs, 236 skips
1259 dezicycles in vc1_put_hor_16b_shift2_mmx, 1048487 runs, 89 skips

3027 dezicycles in vc1_put_ver_16b_shift2_mmx, 1048415 runs, 161 skips
1259 dezicycles in vc1_put_hor_16b_shift2_mmx, 1048515 runs, 61 skips

3030 dezicycles in vc1_put_ver_16b_shift2_mmx, 1048384 runs, 192 skips
1258 dezicycles in vc1_put_hor_16b_shift2_mmx, 1048516 runs, 60 skips

Probably other CPUs are different...

Greetings,
Reimar D?ffinger