[FFmpeg-devel] Amazing intrinsics improvments in gcc 4

[Michael Niedermayer]

On Wed, Mar 19, 2008 at 08:22:32PM +0100, Reimar D?ffinger wrote:
> On Wed, Mar 19, 2008 at 03:01:27PM -0400, Alexander Strange wrote:
> > On Mar 19, 2008, at 2:43 PM, Michael Niedermayer wrote:
> > > So where is that "excellent code is produced using MMX intrinsics" ???
> > 
> > It's in gcc 4.4:
> > gcc version 4.4.0 20080318 (experimental) (GCC)
> >          subl    $12, %esp
> >          movq    _w, %mm0
> >          paddw   %mm0, %mm0
> >          movq    %mm0, _w
> >          movq    _w, %mm0
> >          movq    %mm0, _dw
> >          addl    $12, %esp
> >          ret
> 
> Uh. "excellent code" seems a _bit_ exaggerated to me here...

Well it has just 3 unneeded instructions between 5 needed ones, thats <50%
id say that is pretty good for gcc ;)

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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