1  /* Verify that NRV optimizations are prohibited when the LHS is an
       2     indirect reference to something that may be call-clobbered. */
       3  /* { dg-do compile } */
       4  /* { dg-options "-O -fdump-tree-optimized" } */
       5  
       6  typedef struct { int x[20]; void *y; } S;
       7  S nrv_candidate (void);
       8  void use_result (S);
       9  void make_escape (S *);
      10  S global_S;
      11  void foo (void)
      12  {
      13    S *result;
      14    S local_S;
      15  
      16    /* We can't perform return slot optimization because global_S is
      17       global and may be clobbered by nrv_candidate.  */
      18    result = &global_S;
      19    *result = nrv_candidate ();
      20    use_result (*result);
      21  
      22    /* We can't perform return slot optimization because local_S is
      23       call_clobbered (its address escapes prior to invoking
      24       nrv_candidate).  */
      25    make_escape (&local_S);
      26    result = &local_S;
      27    *result = nrv_candidate ();
      28    use_result (*result);
      29  }
      30  
      31  /* { dg-final { scan-tree-dump-times "return slot optimization" 0 "optimized" } } */
      32