https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87263
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- This is because dominated_by_p_w_unex called by rpo_elim::eliminate_avail is looking at edges we have not yet processed. This might be also an issue when iterating because we may "leak" previous iteration state into the current iteration and may end up failing to iterate.