1  /* Verify that structure return doesn't invoke memcpy on 
       2     overlapping objects.  */
       3  
       4  extern void abort (void);
       5  
       6  struct S {
       7    char stuff[1024];
       8  };
       9  
      10  union U {
      11    struct {
      12      int space;
      13      struct S s;
      14    } a;
      15    struct {
      16      struct S s;
      17      int space;
      18    } b;
      19  };
      20  
      21  struct S f(struct S *);
      22  void g(union U *);
      23  
      24  void main_test(void)
      25  {
      26    union U u;
      27    u.b.s = f(&u.a.s);
      28    u.a.s = f(&u.b.s);
      29    g(&u);
      30  }