http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50328
--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-09-09 09:05:39 UTC --- Ah, we fail outer loop vectorization because of a bug (versioning for alias required) and then drop into vectorizable_reduction with a statement with a operand def that is a PHI with vect_unused_in_scope which of course does not have its vector type set. It's also not marked live for some reason. Doh, seems to be a genuine swap_tree_operands bug.
