[MPlayer-dev-eng] [PATCH] configure cmov detection

[Ivan Kalvachev]

2006/10/18, Guillaume POIRIER <poirierg at gmail.com>:
> Hi,
>
> On 10/15/06, Ivan Kalvachev <ikalvachev at gmail.com> wrote:
> > 2006/10/15, Diego Biurrun <diego at biurrun.de>:
> > > On Sun, Oct 15, 2006 at 08:36:23PM +0300, Ivan Kalvachev wrote:
>
> > > > I had also disable cmov for runtime-cpu detection as we need to make
> > > > the code handle it first.
> > >
> > > Hmm?  You mean the runtime-cpudetection routines need to be updated
> > > first?
> >
> > of course.
>
> I'm not sure what you have on your mind, but as Michael said on
> ffmpeg, it's not worth compiling in 2 versions of the same code and
> switch to one of the version depending on if CMOV is supported or not.
>
> It's much simpler not to compile in any routine that contains CMOV if
> runtime cpu detection is set.
> Bear in mind that CMOV doesn't nearly bring as much as a speed-up and
> MMX can, and that function pointers add some overhead.

And this is what I have done.

Indeed, most (all?) of CMOV code is in .h files and is actively inlined...
It would be really hard to handle it :)