http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51078
--- Comment #16 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-11-12 12:11:48 UTC --- By the way, without having investigated at all what the optimizers are actually doing, in mainline, on an i7-980X I have here at hand I don't see the manual unrolling providing any advantage over -funroll-loops: I'm using g++ -Ofast -march=native -funroll-loops test.cc. Numbers attached.
