1  /* { dg-do run } */
       2  
       3  union U { long long i; long f; };
       4  struct a {union U u;};
       5  struct aa {struct a a;};
       6  struct b {union U u;};
       7  struct bb {struct b b;};
       8  
       9  long __attribute__((noipa))
      10  foo (struct bb *bv, void *ptr)
      11  {
      12    struct aa *a = ptr;
      13    struct bb *b = ptr;
      14    bv->b.u.f = 1;
      15    a->a.u.i = 0;
      16    b->b.u.f = 0;
      17    return bv->b.u.f;
      18  }
      19  
      20  int
      21  main ()
      22  {
      23    union C {struct aa aa; struct bb bb;} v;
      24    if (foo (&v.bb, &v) != 0)
      25      __builtin_abort ();
      26    return 0;
      27  }