https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79095
--- Comment #7 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #6) > VRP already handles that, Nice :-) Thanks and sorry for not checking myself. > IFN_*_OVERFLOW can appear already during gimplification if > __builtin_*_overflow{,_p} is used in the source. Yes, I meant that in the original testcase of this PR, widening_mul is the first dump that contains OVERFLOW. Otherwise, indeed the builtins, and match.pd seems to have one transform that can produce IFN_MUL_OVERFLOW.