https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81354
--- Comment #6 from Bill Schmidt <wschmidt at gcc dot gnu.org> --- Hm, the symptom looks very much like another issue I've been looking at on trunk. There may be an issue with the statement->candidate mapping hash table that's responsible for both. It appears to be a somewhat rare issue involving chains of phis where one of the "more recent" phis is receiving the same value from at least two different incoming edges, but I don't yet have a complete answer.
