[vlc-devel] commit: Add a CPU capability for ARM NEON ( Rémi Denis-Courmont )

[Rémi Denis-Courmont]

Le dimanche 6 septembre 2009 22:08:33 Måns Rullgård, vous avez écrit :
> "Rémi Denis-Courmont" <remi at remlab.net> writes:
> > Le dimanche 6 septembre 2009 21:09:24 Måns Rullgård, vous avez écrit :
> >> git at videolan.org (git version control) writes:
> >> > vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sat Sep
> >> >  5 16:56:25 2009 +0300| [600d29043eed8f9c3e848dddb79bb0e2e9a0a391] |
> >> > committer: Rémi Denis-Courmont
> >> >
> >> > Add a CPU capability for ARM NEON
> >> >
> >> > Currently, detection is done at build time. Feel free to add run-time
> >> > detect if you know how.
> >>
> >> Runtime detection is not possible in any sensible way.  I've discussed
> >> various options with ARM, and we had some ideas for how to make life
> >> easier for apps that need to know.  Unfortunately, I haven't had time
> >> to do much yet.
> >
> > It seemed to me more like a toolchain problem; I cannot configure
> > gcc to accept inline NEON assembly, while otherwise generating plain
> > ARM machine code. On PPC and x86, we simply check whether one
> > instruction triggers SIGILL.
>
> Catching SIGILL isn't such a good idea in general, but if it works for
> you, oh well.

Actually... we used to catch and long jump. That was a bad idea. Now we just 
fork and check the exit status in the parent. What's wrong with checking if 
the process died due to SIGILL?

-- 
Rémi Denis-Courmont
http://www.remlab.net/