1  /* { dg-do link } */
       2  /* { dg-options "-O2" } */
       3  
       4  struct S
       5  {
       6    int w, x, y, z;
       7  };
       8  
       9  struct T
      10  {
      11    int r;
      12    struct S s;
      13  };
      14  
      15  void link_error (void);
      16  int bar (struct S, int);
      17  
      18  void
      19  foo (int a, struct T b)
      20  {
      21    struct S *c = 0;
      22  
      23    if (a)
      24      c = &b.s;
      25  
      26    b.s.w = 3;
      27  
      28    /* Since 'c' may be pointing to NULL here, we used to flag it as
      29       pointing anywhere, which was forcing the aliaser to mark as
      30       call-clobbered every other variable pointed-to by 'c' ('b' in
      31       this case).  This, in turn, caused the insertion of V_MAY_DEFs
      32       for 'b' at this call-site, which prevented constant propagation
      33       from 'b.s.w = 3' to 'if (b.s.w != 3)'.  */
      34    bar (*c, a);
      35  
      36    if (b.s.w != 3)
      37      link_error ();
      38  }
      39  
      40  int main ()
      41  {
      42    struct T b;
      43    foo (3, b);
      44    return 0;
      45  }
      46  
      47  int X;
      48  
      49  int bar (struct S x, int i)
      50  {
      51    X = 3;
      52  }