https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85645
--- Comment #9 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed May 9 12:12:33 2018 New Revision: 260074 URL: https://gcc.gnu.org/viewcvs?rev=260074&root=gcc&view=rev Log: regcprop: Avoid REG_CFA_REGISTER notes (PR85645) Changing a SET that has a REG_CFA_REGISTER note is wrong if we are changing the SET_DEST, or if the REG_CFA_REGISTER has nil as its argument, and maybe some other cases. It's never really useful to propagate into such an instruction, so let's just bail whenever we see such a note. PR rtl-optimization/85645 * regcprop.c (copyprop_hardreg_forward_1): Don't propagate into an insn that has a REG_CFA_REGISTER note. Modified: trunk/gcc/ChangeLog trunk/gcc/regcprop.c