https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57003
--- Comment #25 from Uroš Bizjak <ubizjak at gmail dot com> --- Patch in testing: --cut here-- Index: regcprop.c =================================================================== --- regcprop.c (revision 215852) +++ regcprop.c (working copy) @@ -1030,6 +1030,12 @@ copyprop_hardreg_forward_1 (basic_block bb, struct assume the value in it is still live. */ if (ksvd.ignore_set_reg) note_stores (PATTERN (insn), kill_clobbered_value, vd); + for (exp = CALL_INSN_FUNCTION_USAGE (insn); exp; exp = XEXP (exp, 1)) + { + rtx x = XEXP (exp, 0); + if (GET_CODE (x) == CLOBBER) + kill_value (SET_DEST (x), vd); + } } /* Notice stores. */ --cut here--