[FFmpeg-devel] Fix Altivec detection on Linux.

[David Woodhouse]

On Wed, 2008-03-19 at 16:30 +0100, Reimar D?ffinger wrote:
> On Wed, Mar 19, 2008 at 10:11:09AM -0400, Ronald S. Bultje wrote:
> > Right now, a ubuntu/ppc package built on a g4 crashes without any notice
> > whatsoever on a g3, that is unacceptable. There's multiple ways to fix it,
> > but the unacceptability of any crash should be generally acknowledged.
> 
> For Ubuntu the existing but disabled check via mfspr IMO is a very much
> better solution.

Why so?

> Does the proposed patch work on older kernels (e.g. 2.4) or what is its
> advantage?

It certainly doesn't crash with SIGILL, like the currently-disabled one.
On kernels without /proc/$$/auxv it'll silently fall back to assuming no
Altivec.

/proc/$$/auxv has been around for a long time, but I don't recall
offhand whether it was already in 2.4. It was a _long_ time ago that I
last cared about 2.4 kernels.

-- 
dwmw2