------- Comment #13 from rguenther at suse dot de 2008-08-04 21:11 ------- Subject: Re: [4.3/4.4 Regression] member function pointer failure with optimization
On Mon, 4 Aug 2008, jason at gcc dot gnu dot org wrote: > ------- Comment #12 from jason at gcc dot gnu dot org 2008-08-04 21:03 > ------- > Well, that's the problem then: we have two POINTER_TYPE to METHOD_TYPE which > are considered equivalent in the front end, but not equivalent in the tree-ssa > types_compatible_p. > > The specific bug seems to be that useless_type_conversion_1 doesn't expect to > need to do structural comparison of non-aggregate types. That's an invalid > assumption; it should check TYPE_STRUCTURAL_EQUALITY_P. Does the attached > patch seem appropriate to you? It fixes the bug for me, though I haven't > regression tested it. Duh, if TYPE_STRUCTURAL_EQUALITY_P is used on non-aggregates then yes, this is a correct patch (the code currently makes FUNCTION_TYPEs and METHOD_TYPEs distinct if they are not pointer-equivalent or linked via TYPE_CANONICAL / TYPE_MAIN_VARIANT). So I would prefer if you add those to the AGGREGATE_TYPE_P case instead of letting it fall-through to the "default" case - we should probably add some gcc_unreachable () to make sure we handled all cases. Thanks, Richard. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37016
