[MPlayer-dev-eng] [PATCH] SSE detection fix for NetBSD/amd64

[Michael Niedermayer]

Hi

On Monday 10 January 2005 02:00, Aurelien Jacobs wrote:
> On Sun, 9 Jan 2005 19:50:01 +0100
>
> Reimar Döffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de> wrote:
> > Hi,
> >
> > On Sun, Jan 09, 2005 at 07:10:55PM +0100, Guillaume POIRIER wrote:
> > > Le vendredi 07 janvier 2005 à 18:42 +0100, Aurelien Jacobs a écrit :
> > > > I didn't found any way to test OS SSE support on x86-64.
> > > > But AFAIK, there is no x86-64 OS which don't support SSE.
> > > > I guess it's safe to assume SEE support on x86-64, whatever the OS
> > > > is. So I propose the following patch, which should make everyone
> > > > happy.
> > > >
> > > > Anyone against it ?
> > >
> > > I'm not. This patch does work well, and allows some faster code to be
> > > enabled.
> > > I posted a bench last Thursday on XviD mailling list to compare the
> > > x86-64 version against IA-32.
> > >
> > > Here are the new figures:
> > >
> > > On x86-64
> > >   XviD Pure C | XviD Edouard SIMD | lavc + SIMD
> > > Pass 1: 37fps | 78fps  SSE: 90fps | 82fps  SSE: 84fps
> > > Pass 2: 11fps | 32fps  SSE: 36fps | 30fps  SSE: 30fps

maybe you should also post the exact command line options used


> > >
> > > Well, I'm quite puzzled why lavc doesn't get boosted by the activation
> > > of SSE, but regarding XviD, when It's run with a SSE1|2-aware mencoder,
> > > it gets a bonus 12%... not bad. Not bad at all!
> >
> > That is because lavc uses cpudetection based in the code in
> > libavcodec/i386/cputest.c.
>
> AFAIR, there's not so much SSE optimisations in lavc. 

yes, SSE is floating point stuff, its not that usefull except at a few places
OTOH SSE2 could be usefull on some cpus, patches & benchmarks are welcome

btw, xvid calls MMX2 SSE, thats certainly one reason why there are more hits 
if u grep for SSE, i suggest u try 'xmm[0-9]' instead


[...]
-- 
Michael

"In any case, just because code is syntactically "valid" GNU C doesn't 
mean gcc can always compile it." -- justification to close a gcc bug