1  /* { dg-do run } */
       2  /* { dg-additional-options "-fno-tree-dse" } */
       3  
       4  union U { long long i; long f; };
       5  struct a {union U u;};
       6  struct aa {struct a a;};
       7  struct b {union U u;};
       8  struct bb {struct b b;};
       9  
      10  long __attribute__((noipa))
      11  foo (struct bb *bv, void *ptr)
      12  {
      13    struct aa *a = ptr;
      14    struct bb *b = ptr;
      15    bv->b.u.f = 1;
      16    a->a.u.i = 0;
      17    b->b.u.f = 0;
      18    return bv->b.u.f;
      19  }
      20  
      21  int
      22  main ()
      23  {
      24    union C {struct aa aa; struct bb bb;} v;
      25    if (foo (&v.bb, &v) != 0)
      26      __builtin_abort ();
      27    return 0;
      28  }