http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44334
--- Comment #17 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2010-12-21 10:46:06 UTC --- For the record I have also tested the patch in comment #14 on powerpc-apple-darwin9 at revision 168070. Without the patch I get [karma] lin/test% gfc -Ofast -funroll-loops -ftree-loop-linear -fomit-frame-pointer -finline-limit=600 --param hot-bb-frequency-fraction=2000 -fwhole-program -flto rnflow.f90 [karma] lin/test% time a.out > /dev/null 68.236u 6.947s 1:17.77 96.6% 0+0k 0+0io 0pf+0w [karma] lin/test% gfc -Ofast -funroll-loops -ftree-loop-linear -fomit-frame-pointer -finline-limit=600 -fwhole-program -flto rnflow.f90 [karma] lin/test% time a.out > /dev/null 65.229u 6.838s 1:14.61 96.5% 0+0k 0+0io 0pf+0w Note a slight slow down with -param hot-bb-frequency-fraction=2000. With the patch I get [karma] lin/test% gfc -Ofast -funroll-loops -ftree-loop-linear -fomit-frame-pointer -finline-limit=600 --param hot-bb-frequency-fraction=2000 -fwhole-program -flto rnflow.f90 [karma] lin/test% time a.out > /dev/null 69.690u 6.917s 1:19.44 96.4% 0+0k 0+0io 1pf+0w [karma] lin/test% gfc -Ofast -funroll-loops -ftree-loop-linear -fomit-frame-pointer -finline-limit=600 -fwhole-program -flto rnflow.f90 [karma] lin/test% time a.out > /dev/null 69.791u 7.225s 1:20.08 96.1% 0+0k 0+0io 0pf+0w i.e., -param hot-bb-frequency-fraction=2000 does not change the timings, but the resulting code is slower.
