[pulseaudio-discuss] detection of SSE3 support in configure.ac

[Rémi Denis-Courmont]

Le mardi 6 décembre 2011 13:00:16 Nallasellan, Singaravelan, vous avez écrit :
> > I have an optimized SSE-based resampling library that I bolted in
> > PulseAudio. It was measured to bring a 2x speed-up over speex, mainly
> > because it uses fixed-tables instead of interpolations, the price being
> > that it can only be used for fixed-rate sinks/sources.
> > Since it's hardware-specific, I'd need a means to enable/disable it at
> > compile time, using some kind of voodoo magic in configure.ac. Does
> > anyone have pointers on SSE detection logic? To make things safe, I also
> > detect SSE at run time but would like to disable it completely for other
> > non-x86 or older platforms.
> 
> CPUID processor instruction should provide all the details about the
> processor.

CPUID is not a complete solution. It will tell you whether the CPU supports 
certain instruction sets. But it does not specify whether the operating system 
supports the SSE registers "xmmX". Thus parsing /proc/cpuinfo is more reliable 
though obviously Linux-specific.

-- 
Rémi Denis-Courmont
http://www.remlab.net/
http://fi.linkedin.com/in/remidenis