[FFmpeg-devel] [PATCH] Fix configure to disable MMX for Pentium Pro

Måns Rullgård mans
Thu Aug 26 15:50:28 CEST 2010

"Ronald S. Bultje" <rsbultje at gmail.com> writes:

> Hi,
> On Thu, Aug 26, 2010 at 9:34 AM, Alex Converse <alex.converse at gmail.com> wrote:
>> ./configure --cpu=prentiumpro says build me an FFmpeg for a
>> PentiumPro. The result will no longer run on a PentiumPro.
> A) It should require --disable-mmx (and thus the configure patch to
> disable mmx should be changed to error out unless mmx is disabled),

That's a stupid idea.  Specifying a CPU without MMX should of course
disable MMX.  That stands to reason.  It is also how all the other
architectures work.

> B) we should revert the mmx-requiring commit and only do unconditional
> emms on x86-64 (I think this is acceptable. Mans?).

The main point of the change was to get rid of the stupid global
mm_flags variable.  We discussed it at length some time ago (it nearly
went full bikeshed), and nobody objected then, not even the distro people.
Why the sudden outrage?

M?ns Rullg?rd
mans at mansr.com

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