https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78559
--- Comment #7 from amker at gcc dot gnu.org --- (In reply to Jakub Jelinek from comment #6) > So do you think combiner should throw away the REG_EQUAL note in that case, > or something different? It's invalid after transformation, so should be discarded in this case. What I am not sure is that how to tell invalid ones from all notes and keep others. I sent a proposed patch for discussion before @https://gcc.gnu.org/ml/gcc-patches/2016-12/msg00026.html Thanks.