[FFmpeg-devel] [PATCH] HAVE_AMD3DNOW

Michael Niedermayer michaelni
Tue Jun 9 04:24:44 CEST 2009

On Mon, Jun 08, 2009 at 09:39:48PM -0400, Pavel Pavlov wrote:
> > -----Original Message-----
> > On Mon, Jun 08, 2009 at 03:30:40PM -0400, Pavel Pavlov wrote:
> > > Hello all,
> > > Intel compiler on win32 doesn't support 3dnow in inline asm 
> > > (unsupported
> > 
> > ahh, intels compiler supports their own but not the competing 
> > SIMD how unexpected ...
> > 
> > iam against the #ifdefs, they are too messy to work around 
> > intels dubious anticompetetive practices.
> It's not about intel or not intel compiler.
> I passed --disable 3dnow and I expect no 3dnow specific code.
> icc (linux intel compiler) supports 3dnow inline asm in att style since
> it passes it to gas; on win32 they have builtin assembler for att style
> asm and it lacks some features.
> It won't accept cltd (it requires CDQ instead), in some places it can't
> accept add and requires addl etc.
> If I run default configure it detects that 3dnow is supported. So, it
> means that some opcodes are supported (if it tries to use 3dnow asm and
> not cpudetect). But while building I had errors due to undefined asm
> instructions, so I had to configure disable-3dnow and put some #if

> So, you think that if disable-3dnow specified 3dnow versions should
> still be compiled in?

i think that your patch is ugly and given that it came in the form of a
fix for a platform which has other supported compilers i see little sense
in it. That said iam not against it in principle if you can do it alot
cleaner ...

If OTOH you want to fix --disable-3dnow, that may be welcome though i
obviously would prefer this to be done as clean as possible. I dont know
what is cleanest but simply not referencing 3dnow functions and letting
the compiler remove them seems like an obvious try

Also, even with iccw 3dnow should be supported not just disabled your
patch is not a clean fix for this ...

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When the tyrant has disposed of foreign enemies by conquest or treaty, and
there is nothing more to fear from them, then he is always stirring up
some war or other, in order that the people may require a leader. -- Plato
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