Re: Re: Ffmpeg Emerge Problem

Frank Peters <[email protected]> Wed, 11 Mar 2015 00:23:03 -0400

Newsgroups	gmane.linux.gentoo.amd64
Message-ID	<[email protected]>

On Wed, 11 Mar 2015 03:25:24 +0000 (UTC)
Duncan <[email protected]> wrote:

> 
> Meanwhile, the 19 new MMX instructions were a subset of Intel's SSE (v1) 
> instruction set.  This SSE subset of 19 instructions is apparently what 
> mmxext actually refers to.  Thus, anything with sse in the cpuflags by 
> definition has mmxext as well.
> 

These flags have to be maintained for backwards compatibility,
I suppose, even though mmxext no longer makes sense on newer
processors.

Also, why the need to even specify the string of "sse sse2 sse3 sse4_1 
sse4_2 ssse3?"  Each successive SSEX includes all previous instructions
so only the highest "X" for a given processor would be appropriate.

Frank Peters