[FFmpeg-devel] [PATCH] Add check for Athlon64 and similar AMD processors with slow SSE2.

Justin Ruggles justin.ruggles
Fri Feb 4 01:04:52 CET 2011

On 02/03/2011 01:58 AM, Jason Garrett-Glaser wrote:

> On Wed, Feb 2, 2011 at 3:26 PM, Justin Ruggles <justin.ruggles at gmail.com> wrote:
>> ---
>> This was ported from x264 so we need permission to relicense from
>> Loren, Jason, or whoever added this particular check in x264.
> That's one line of code, it's too trivial to matter.
> But keep in mind that SSE2SLOW seems to mean something different in
> ffmpeg.  It's already used for the case of Core 1, where SSE2 is
> ALMOST ALWAYS slower than MMX.  But on Athlon 64, it's mostly faster,
> just slower in some cases.

Yes, but it's still possible to reuse this flag because we disable
AV_CPU_FLAG_SSE2 in the case of Core 1.  Although it would make things
slightly more complex in the case where you want to enable an SSE2
function on Core 1 but disable it on Athlon64.  So I'll send a new patch
that adds a separate flag.


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