https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121773
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Most likely r12-11174-gaffa145910b676 or r12-10976-g77172598dcb07b caused it. Those 2 combine patches are the ones on all 3 release branches when it seems like it started to go wrong. Based on the anlaysis in comment #0 r12-11174-gaffa145910b676 seems more likely but I could be wrong. And I don't see an REG_UNUSED note here either.
