Gentoo Archives: gentoo-dev

From: Danny van Dyk <kugelfang@g.o>
To: gentoo-dev@l.g.o
Subject: [gentoo-dev] [RFC] Adding CPUFLAGS USE_EXPAND variable to the profiles
Date: Fri, 07 Jul 2006 14:18:59
OK, this rfc/proposal is competing with Flameeye's proposal:

I suggest to add a "CPUFLAGS" USE_EXPAND variable to the tree.
This should be set to sane defaults in the profiles. I.e. for x86,
it should not set CPUFLAGS at all, and on AMD64 it should be
  CPUFLAGS="mmx sse sse2"

I'm no quite sure, but i assume ppc/ppc32 should leave CPUFLAGS empty,
and ppc/ppc64 should set

The main reasons for a USE-like implementation om contrast to Diego's 
proposal are:

a) There is no call to gcc involved, but only a call to use(). This
   allows usage in metadata phase.
b) There is no implicit (non-transparent) choice made for the users.
c) It doesn't mix CFLAGS' purpose (which has a meaning beyond Gentoo)
   with the purpose of optional codepaths.

I know, there aren't use-based deps in portage yet, but I really feel
uncomfortable to be unable to use cpuflags in metadata phase. This is 
what worries me most.

Danny van Dyk <kugelfang@g.o>
Gentoo/AMD64 Project, Gentoo Scientific Project
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