[FFmpeg-devel] [PATCH] Get rid of unused PREFETCHW and prefer MMX2 over 3DNow!

Michael Niedermayer michaelni
Sat Jan 9 15:28:34 CET 2010


On Sat, Jan 09, 2010 at 10:22:59PM +0800, Zuxy Meng wrote:
> 2010/1/8 Michael Niedermayer <michaelni at gmx.at>:
> > On Fri, Jan 08, 2010 at 11:37:17AM +0800, Zuxy Meng wrote:
> >> Hi,
> >>
> >> We never used PREFETCHW in libswscale, and MMX2's prefetchnta is
> >> preferrable than 3DNow!'s prefetch due to the former's non temporal
> >> hint.
> >>
> >> --
> >> Zuxy
> >> Beauty is truth,
> >> While truth is beauty.
> >> PGP KeyID: E8555ED6
> >
> >> ?rgb2rgb_template.c | ? 12 ++++--------
> >> ?swscale_template.c | ? 10 +++-------
> >> ?2 files changed, 7 insertions(+), 15 deletions(-)
> >> 596c1966a2582e14b7eec570fd57db77da8d8386 ?prefetch.diff
> >> Index: libswscale/swscale_template.c
> >> ===================================================================
> >> --- libswscale/swscale_template.c ? ? (?? 30234)
> >> +++ libswscale/swscale_template.c ? ? (??????)
> >> @@ -25,17 +25,13 @@
> >> ?#undef MOVNTQ
> >> ?#undef PAVGB
> >> ?#undef PREFETCH
> >> -#undef PREFETCHW
> >>
> >> -#if COMPILE_TEMPLATE_AMD3DNOW
> >> -#define PREFETCH ?"prefetch"
> >> -#define PREFETCHW "prefetchw"
> >> -#elif COMPILE_TEMPLATE_MMX2
> >> +#if COMPILE_TEMPLATE_MMX2
> >> ?#define PREFETCH "prefetchnta"
> >> -#define PREFETCHW "prefetcht0"
> >> +#elif COMPILE_TEMPLATE_AMD3DNOW
> >> +#define PREFETCH ?"prefetch"
> >> ?#else
> >> ?#define PREFETCH ?" # nop"
> >> -#define PREFETCHW " # nop"
> >> ?#endif
> >
> > you are mixing 2 unrelated changes in one patch (which makes it unreadable)
> 
> So the updated one that removes PREFETCHW only.
> -- 
> Zuxy
> Beauty is truth,
> While truth is beauty.
> PGP KeyID: E8555ED6

>  rgb2rgb_template.c |    4 ----
>  swscale_template.c |    4 ----
>  2 files changed, 8 deletions(-)
> 84258f05157cab9ee37b40695f974cc9bcf7a6cc  prefetch.diff

ok

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

I wish the Xiph folks would stop pretending they've got something they
do not.  Somehow I fear this will remain a wish. -- M?ns Rullg?rd
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