1  /* { dg-do compile } */
       2  /* { dg-options "-O2" } */
       3  
       4  struct shared_ptr_struct
       5  {
       6    unsigned long phase : 48;
       7    unsigned thread : 16;
       8    void *addr;
       9  } x;
      10  
      11  void foo (void)
      12  {
      13     x.thread = 2;
      14  }