https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71031
--- Comment #9 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- > The situation (+ UINT_MAX) is equal to [1, od_5] - 1 which would mean > a result range of ideally [0, od_5 - 1]. Right. > I think Eric added this code so he may want to have a look here to see > what general solution is appropriate. > > But yes, instead of asserting we can always drop to VR_VARYING ... That's what the block of code just above was added for: /* If we have overflow for the constant part and the resulting range will be symbolic, drop to VR_VARYING. */ if ((min_ovf && sym_min_op0 != sym_min_op1) || (max_ovf && sym_max_op0 != sym_max_op1)) { set_value_range_to_varying (vr); return; } so a safe fix is to extend it to catch this case: /* If we have overflow for the constant part and the resulting range will be symbolic, drop to VR_VARYING. */ if ((min_ovf || max_ovf) && (sym_min_op0 != sym_min_op1 || sym_max_op0 != sym_max_op1)) { set_value_range_to_varying (vr); return; } If we want to compute the above expected range, we need to enter the business of symbolic ranges with TYPE_OVERFLOW_WRAPS, which is rather delicate. And we also need to short circuit the final call to compare_values, which will drop to VR_VARYING if I'm not mistaken.