http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52055
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-02-01 16:35:13 UTC --- That's true, but currently REE is after reload, this combining would be better done before reload. Perhaps a separate post-combine pre-ira pass could handle that and also perhaps PR50176 (if it is somehow possible to insert CC clobbers to insns that don't have it safely). The UD/DU links computation REE does is very expensive I think.
