http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54146
--- Comment #29 from Steven Bosscher <steven at gcc dot gnu.org> 2012-08-07 22:28:11 UTC --- Created attachment 27957 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27957 Do not traverse sibling loops The idea here is to note that for a nested loop we know for sure that the loop exits into a common loop father must all need PHI nodes, because we have have loop pre-headers. I'm not sure what the effect of this is on irreducible loops, and I haven't tested this much yet. Comments sought...
