[FFmpeg-devel] [PATCH] h264_i386: Optimize decode_significance_8x8_x86 for 64 bit.

Reimar Döffinger Reimar.Doeffinger at gmx.de
Sat Nov 22 14:09:01 CET 2014


On Mon, Nov 17, 2014 at 01:41:13PM +0100, Michael Niedermayer wrote:
> On Mon, Nov 17, 2014 at 08:19:32AM +0100, Reimar Döffinger wrote:
> > On 17.11.2014, at 02:37, Michael Niedermayer <michaelni at gmx.at> wrote:
> > > On Sat, Nov 15, 2014 at 06:16:03PM +0100, Reimar Döffinger wrote:
> > >> 11674 -> 10877 decicycles on my Phenom II.
> > >> Overall speedup was unfortunately within measurement error.
> > > 
> > > here its  10153 ->10135
> > 
> > I suspect it also depends a bit on the compiler and how it changes the surrounding code.
> > Note that I also tested with PIC actually.
> > 
> > > but ive a slightly odd feeling about the chnages to the asm code,
> > > iam not sure if all assemblers will be happy about the changed
> > > code
> > 
> > Do you mean particularly the movzbl change?
> 
> yes and the k stuff
> 
> 
> > I am also unsure about that, I think there was a reason for that %k6 mess...
> > But this as well as movzx seemed to work for me...
> 
> it works here too i just have the feeling it might fail on some odd
> assembler or platform. Thats not meant to keep you from pushing this
> just that it might require to be reverted or fixed if such
> problems actually occor

I pushed it.
If anyone sees issues please tell me and I'll look into it!


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