https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109689
--- Comment #8 from Jan Hubicka <hubicka at gcc dot gnu.org> --- An easy way would be to avoid unlooping if tree_ssa_loop_ch is executed in loop closed ssa (which happens from ch_vect pass). I wonder how hard would be however to get this right? I think this means to take the basic block we turn into unreachable and look on its predecessors that are in loop introducing new PHIs and renaming. This is bit involved to do by hand. So perhaps simply: rewrite_into_loop_closed_ssa (NULL, 0); in case we unlooped in loop closed ssa form (which is not that common). Would that be acceptable?
