http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58380
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> --- The symptom hints at a released SSA name being looked at. That happens if cfgcleanup looks at a dead code region (we especially run TODO_cleanup_cfg before TODO_update_ssa to allow passes to be forgiving with not removing dead blocks). Eventually we guarded these foldings but seem to have removed the guarding again.
