[Bug target/40644] Optimizing for pentium-m gives worse code than optimizing for i486
--- Comment #3 from aanisimov at inbox dot ru 2009-07-03 19:12 --- > > Try disabling prefetching. > Indeed, removing -fprefetch-loop-arrays made the program run in 37.534 seconds, exactly like one compiled for i686. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40644
[Bug target/40644] Optimizing for pentium-m gives worse code than optimizing for i486
--- Comment #2 from rguenth at gcc dot gnu dot org 2009-07-03 18:55 --- Try -march=pentium-m -mtune=generic. Pentium-M never received any special tuning (it is the same as for pentium-pro). So is -march=i686 btw, but i686 does not have SSE, so it is likely vectorization and/or prefetching that slows your case 3. down. Try disabling prefetching. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40644
[Bug target/40644] Optimizing for pentium-m gives worse code than optimizing for i486
--- Comment #1 from aanisimov at inbox dot ru 2009-07-03 18:28 --- Created an attachment (id=18137) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18137&action=view) Sample program -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40644
