[PlanetCCRMA] Package rebuilding + CPU optimizations

[Fernando Lopez-Lezcano]

On Fri, 2005-10-07 at 14:01 +0000, Luis Garrido wrote:
> I was wondering if recompilation of alsa-modules, jackd and CPU intensive 
> applications (fluidsynth, linuxsampler, ladspa's, dssi's, zynaddsub...) 
> might benefit of CPU optimizations and thus improve performance. In order to 
> preserve the integrity of the package management system, what would be the 
> better procedure? I reckon that downloading the SRPMS from
> 
> http://ccrma.stanford.edu/planetccrma/mirror/all/linux/SRPMS/
> 
> and then using rpmbuild, right? Is it necessary to tweak the spec file to 
> include the CPU optimizations?
> 
> Did anyone already try this and can report whether the results are or not 
> worth the pain?

You probably won't see any difference. A few "critical" packages are
i386/i686, the rest is i386 _but_ with intruction ordering tuned for
i686 cpus. The extra instruction(s) in the i686 architecture apparently
don't make a difference in modern cpus. But tuning the instruction
ordering does make a difference (on Intel cpus, AMD cpus apparently
don't care that much about that). 

-- Fernando