On Mon, 12 Mar 2012 21:44:21 Jeroen Demeyer wrote: > On 2012-03-12 19:48, Volker Braun wrote: > > I'm all in favor of adding the gcc spkg. > > > > One thing that I'm not entirely happy with is that we bulid gcc without > > graphite/ppl/cloog, so I suspect that the code speed isn't as good as it > > could be. But since we only use the self-compiled gcc if the os-supplied > > one is crap I think its fine. > > Well, I believe Graphite is used only when you supply specific command > line options to gcc (-O3 is not sufficient). Since those options are > rarely/never supplied by the various SPKGs, I don't think there is much > to gain by adding CLooG. Correct. The options you get with graphite are: -floop-interchange -floop-strip-mine -floop-block there is also -fgraphite-identity but I believe it is available when you have both graphite and lto at the same time.
I tested the graphite optimization on some lattice QCD code that has many levels of looping and the benefits were quite significant (around 30%). I was extremely impressed. Francois -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
