[MPlayer-cvslog] r25380 - trunk/etc/codecs.conf

[Ivan Kalvachev]

On Dec 20, 2007 3:12 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> Hi
>
> On Thu, Dec 20, 2007 at 02:06:09PM +0100, Aurelien Jacobs wrote:
> > Diego Biurrun wrote:
> >
> > > On Wed, Dec 19, 2007 at 11:50:32AM +0100, Reimar Döffinger wrote:
> > > > On Wed, Dec 19, 2007 at 08:56:20AM +0100, Diego Biurrun wrote:
> > > > > On Wed, Dec 19, 2007 at 01:13:56AM -0500, Rich Felker wrote:
> > > > [...]
> > > > > > Probably using cmov...
> > > > >
> > > > > How can I find out?
> > > >
> > > > Find out on which instruction it crashes. Everything you need is the
> > > > bug-report howto :-P
> > >
> > > Hmm...
> > >
> > > (gdb) bt
> > > #0  0x100026db in ?? ()
> >
> >       ^^^^^^^^^^
> > address of the crash...
> >
> > > 0x100026db:     pshufw $0xa0,%mm1,%mm1
> >                   ^^^^^^
> > instruction which crash...
> >
> > Google tells me that pshufw is an SSE instruction (so it's not
> > available on K6-III).
>
> the above is a MMX2 instruction, also called MMX-SSE (=an MMX instruction
> which was added together with SSE on intel CPUS)
> see http://www.sandpile.org/ia32/opc_2.htm

I think the proper naming is MMX-EXT (as seen in /proc/cpuinfo).
This means it could be queried via cpuid. The codec should do that already.
If somebody wants to patch the codec he may try looking around the
cpuid code and fix it.
It is also possible that the codec have registry entry that disables
some or all SIMD extensions.