https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92584
--- Comment #3 from rguenther at suse dot de <rguenther at suse dot de> --- On Wed, 20 Nov 2019, marxin at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92584 > > --- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> --- > (In reply to rguent...@suse.de from comment #1) > > On Tue, 19 Nov 2019, marxin at gcc dot gnu.org wrote: > > > > > I noticed that the speed drop back on the trunk happened since r278281. > > > Would you be interested in what loop optimization made the difference? > > > > Well, the revs probably caused changes in (early) unrolling with the > > better performance seen with less unrolling. We know that even more > > unrolling will increase performance though. > > Ok, so the benchmark likes unrolling :) > > > > > Not sure what you are asking? > > My question is simple: Can we somehow tweak our defaults so that we can speed > up calculix. Note that the speed up is 2x. I've tried multiple times to no avail ... :/ But yeah. I'll have another look ;) It's gfortran.dg/reassoc_4.f btw. IIRC. See also the --param adjustment therein ... Honza lowered the param at some point, regressing things.
