------- Comment #8 from bonzini at gnu dot org 2008-11-22 16:00 ------- The problem was that without -fprofile-generate the time spent there was basically zero. Since the profiling code is building a MST of the control-flow graph, it should produce absolutely no PRE opportunity and it's a pity that it causes such a slowdown.
I wonder if there is some low-hanging fruit to eliminate value numbers that cannot be redundant. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35639
