http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53338
--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-05-14 09:32:31 UTC --- (In reply to comment #5) > > 20% runtime regression in rnflow [1] happened in this timeframe, perhaps it > > could be attributed to the patch, mentioned in Comment #2. > > This slowdown is caused by revision 187092 in the proc cptrf2. That patch was supposed to be a no-op on code generation. > A further > slowdown (~5%) is caused by revision 187340 in the proc evlrnf. While tracking > these slowdowns I also noticed that for any revision compiling rnflow.f90 is > slower if I use -O3 only compared to the use of -O2 only (cptrf2 seems the > culprit). The best timings I get are when I compile evlrnf with '-O3 > -ffast-math -funroll-loops'. > > I am planning to open some PRs about these findings which do not seem related > to this one (unless someone beat me).
