https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69156
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Richard Biener from comment #3) > (In reply to Jakub Jelinek from comment #2) > > Created attachment 37266 [details] > > gcc6-pr69156.patch > > > > Untested fix. Not sure if it is the best spot though. And the testcase is > > really nasty. > > Hmm, but this means things were mismatched in the first place (earlier) and > thus this should be checked somewhere else? This happens in gimple-match-head.c: 714 tree decl = TREE_OPERAND (fn, 0); 715 if (DECL_BUILT_IN_CLASS (decl) != BUILT_IN_NORMAL 716 || !gimple_builtin_call_types_compatible_p (stmt, decl)) 717 return false; and the problem is that gimple_builtin_call_types_compatible_p is extremely lose (basically, for return type or arguments considers all integral types equal, or all pointer types equal, or all RECORD_TYPEs equal etc.). Bet for this purpose (but don't about all the others) it might be better to check useless_type_conversion_p equality instead. I guess the question is when is a mere validate_type instead of types_compatible_p useful.
