Re: [gentoo-user] USE="mmx mmxext sse sse2 ssse3 3dnow 3dnowext"

[Daniel Iliev <daniel.iliev@gmail.com>]

On Thu, 28 May 2009 00:23:52 +0300
"Arttu V." <arttuv69@gmail.com> wrote:

> On 5/27/09, Wyatt Epp <wyatt.epp@gmail.com> wrote:
> > Reading this thread, though, it seems like it would be useful to
> > have a FEATURES=cpudetection for Portage.
> 
> Congratulations, it's already there! Sort of. -march=native ;)
> 

Not the same thing. "-march=" instructs gcc to produce a binary
designed to run only on the given CPU architecture, while
USE flags instruct the build system to include or not support for a
given feature. Think of the USE flags "this" and "that" as shortcuts to
"./configure --enable-this --disable-that".

So, for example mplayer could be a binary which can take advantage (or
not) of SSSE3 and is designed to run only (or not) on core2.


P.S.

And what's next - feature like:

FEATURES="do_the_best_system_ever"

where "do_the_best_system_ever" is a shorthand for:

detect_best_cflags
detect_best_cxxflags
detect_best_ldflags
detect_best_uselags

Sounds good and it's not against Gentoo philosophy - the end user has
the choice to use this feature or not. Any volunteers for the
implementation? Oh, wait! Somebody define "best", please! :)


-- 
Best regards,
Daniel