http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59811
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- With -O2 -fno-automatic -ffixed-line-length-none --param sccvn-max-alias-queries-per-access=1300 the combiner completely disappears out of the picture, supposedly because then FRE/PRE doesn't give up, with 1200 the combiner already takes 17% of compile time and 77% of memory, with the default 1000 it takes 58% of compile time and 96% of memory.
