On Wed, Jun 17, 2009 at 1:52 PM, Bill Nottingham<notting@xxxxxxxxxx> wrote: > Given the loud feedback, I've updated the proposal at: > https://fedoraproject.org/wiki/Features/F12X86Support > > The revised proposal: > > - Build all packages for i686 (this requires cmov) > - Optimize for Atom > > Why? > > - We don't really support i586 in any meaningful matter > - OLPC still works with base i686 > - We are likely doing a mass rebuild for F-12 anyways, might as well switch > while we're doing it > - Atom is the only currently produced 32-bit x86 chip of note; optimize > for what's currently available > > If you want numbers, I did some benchmarking of code [1] with various > build options on a variety of processors, with the F-11 gcc code. All > of these results are relative to a F-11 baseline of "-march=i586 > -mtune=generic". > > P4 2.4Ghz Athlon 3400+ Core2Duo E6850 Atom N270 > march=i686/ -1.1% +2.0% +0.9% +0.6% > mtune=generic > march=i586/ +0.3% -0.3% -0.2% +1.3% > mtune=atom > march=i686/ -1.5% +1.2% +0.5% +1.7% > mtune=atom If there is a mass rebuild… Consider: -Os on the x86 build? -O3 on x86_64? (Back in 2007 I would have screamed loudly that the auto-vectorizer produces broken code; but today it appears to work fine.) -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
