https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109829
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #4) > Or does match.pd try to invert all the COND_EXPR conditions and swap the > operands? match does not try but phiopt does in gimple_simplify_phiopt . Or even something like this would work better. (for neeq (ne eq) (simplify (cond (neeq (SIGNBIT @0) zero_p@1) (neg @0) @0) (if (neqeq == NE_EXPR) (abs @0) (neg (abs @0)) ) ) ) ) I need to double check if == 1 will show up here though.