[FFmpeg-devel] [PATCH] Optimisations for av_log2 and integer clip functions

Michael Niedermayer michaelni
Wed Jan 13 23:49:10 CET 2010

On Wed, Jan 13, 2010 at 10:10:30PM +0000, M?ns Rullg?rd wrote:
> Jason Garrett-Glaser <darkshikari at gmail.com> writes:
> > Also, __builtin_clz/ctz maps to bsr/bsf, which are extraordinarily
> > slow on Athlons.
> Fabulous.  So what shall we do?  List the CPUs with good clz support
> in configure like we do with cmov et al?

yes, if someone wants to use it

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I hate to see young programmers poisoned by the kind of thinking
Ulrich Drepper puts forward since it is simply too narrow -- Roman Shaposhnik
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