https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107172
--- Comment #27 from H.J. Lu <hjl.tools at gmail dot com> --- Another oddity is (set (pc) (if_then_else (eq (reg:CCO FLAGS_REG) (const_int 0)) (label_ref (match_operand 3)) (pc)))] CCOmode means that the overflow flag is tested. EQ means that the flag is set and NE means unset.