1  /* { dg-do compile } */
       2  /* { dg-options "-O2" } */
       3  /* { dg-final { scan-assembler "dont_delete" } } */
       4  
       5  typedef struct { int x; } __attribute__((may_alias)) S;
       6  
       7  extern void dont_delete (void);
       8  
       9  void f(S *s, float *f)
      10  {
      11    s->x = 1;
      12    *f = 0;
      13    if (s->x != 1)
      14      dont_delete ();
      15  }