[FFmpeg-devel] [PATCH] x86/swr: add ff_float_to_int32_a_avx2

[Michael Niedermayer]

On Fri, Nov 07, 2014 at 01:19:22PM -0300, James Almer wrote:
> On 07/11/14 6:05 AM, Christophe Gisquet wrote:
> > Hi,
> > 
> > 2014-11-06 23:04 GMT+01:00 James Almer <jamrial at gmail.com>:
> >> No, the function checks for alignment and jumps to a branch that uses movdqu if needed.
> >> ff_int32_to_float_a_avx also uses ymm regs and this same macro.
> > 
> > OK, so nothing new here, same 32-bytes alignment.
> > 
> >> when "mulps m0, m1, [mem]" would work just as well regardless of alignment.
> > 
> > It does with AVX? That shows I never used it...
> 
> http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-1-manual.pdf
> Chapter 14.9. It's pretty convenient, but taking advantage of it would require uglyfing macros 
> or making the avx functions separate.
> 
> > 
> >> If you use "cmpps m0, m1, 5" it will work for non-VEX coding, but error out otherwise
> >> since x86inc.asm turns that into "vcmpps m0, m1, 5" instead of "vcmpps m0, m0, m1, 5"
> >>
> >> With aliases like cmpnltps it doesn't even add the "v" prefix.
> > 
> > OK. As you are the number one developer for AVX, it's up to you
> > whether that would need a more generic fix :-)
> > 
> > Someone actually used to AVX should comment, but this patch looks so
> > simple that you should apply it tomorrow if nobody objects.
> > 
> 
> I was waiting for Michael to comment since he's the swr maintainer. Otherwise I'd have pushed 
> it after your ok.

please push patches which Christophe reviewed
no need to wait for me

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are too smart to engage in politics are punished by being
governed by those who are dumber. -- Plato 
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