http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54300
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |ebotcazou at gcc dot gnu.org --- Comment #10 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- > and regcprop substitues d19 for d18 in insn 27, missing the fact that insn > 73 is swapping the two values (thus clobbering the old d19 value). It's probably fooled by single_set returning the first set of the insn because of the REG_UNUSED note. I wonder whether it's a generic pitfall of single_set.