http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61020
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- _ZTI7Derived.0_1 = &_ZTI7Derived; _3 = MEM[(const struct type_info *)_ZTI7Derived.0_1]._vptr.type_info; _4 = _3 + 18446744073709551608; _5 = *_4; Is being optimized to be 0 for some reason. Looks like _ZTVN10__cxxabiv120__si_class_type_infoE (vtable for __cxxabiv1::__si_class_type_info) is not being recorded correctly inside GCC.