[FFmpeg-devel] [PATCH] Fix configure to disable MMX for Pentium Pro

[Reimar Döffinger]

On Thu, Aug 26, 2010 at 09:53:44PM +0200, Michael Niedermayer wrote:
> On Thu, Aug 26, 2010 at 08:52:24PM +0200, Reimar D?ffinger wrote:
> > On Thu, Aug 26, 2010 at 01:37:06PM -0400, Alex Converse wrote:
> > > > We should revert r24946: ?Disable MMX for i686 and pentiumpro
> > > 
> > > If something should be reverted it is dropping runtime detection for MMX
> > 
> > At the very least I think it would be nice to be able to have SSE,
> > does someone know out of their head why we have
> > sse_deps="mmx"
> > ? I always thought that at least in principle you could have and
> > use SSE without MMX and that also would avoid the emms issue...
> 
> there is no cpu that supports SSE without MMX and if the features no
> longer match the cpu then alot of assumtations of what is faster and
> what cpus code will run on become wrong
> its btw silly to disable mmx on a mmx cpu unless its for debuging or other
> uncommon things

How about "emms causes all kinds of issues, I'd like a build without
those issues but still ok speed?"