https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118509
--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Renamed/reformatted: struct A { void foo () { a = 1; } int a = 0; }; struct B : virtual A {}; typedef void (A::*C) (); __attribute__((noipa)) void foo (C x, B *y) { (y->*x) (); } int main () { B b; foo (&A::foo, &b); if (b.a != 1) __builtin_abort (); } Note, r15-4595 has been backported to 14 branch in r14-10839, so it also a regression from 14.2 to 14.3.