https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99927
--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Segher Boessenkool from comment #11) > (In reply to Jakub Jelinek from comment #7) > > Ah, create_log_links wants to work like that. > > So, the bug seems to be that insn 108 has REG_DEAD (reg:CC 17 flags) note. > > It doesn't initially, but it is added during 106 -> 108 combination > > But that combination should never have been made: flags is set in insn 107! Why? It is not across a LOG_LINK for the flags register, but for the r134 pseudo. Yes, the first insn has a clobber on flags, but don't most of x86 insns have that? The combiner doesn't move over the clobber, it just substs r134 to its SET_SRC.
