1  /* { dg-do compile } */
       2  /* { dg-options "-O1 -fstrict-aliasing -fdump-tree-cddce1" } */
       3  
       4  __extension__ typedef __SIZE_TYPE__ size_t;
       5  extern void *xmalloc (size_t) __attribute__ ((__malloc__));
       6  struct edge_def
       7  {
       8    struct basic_block_def *dest;
       9    int flags;
      10  };
      11  typedef struct edge_def *edge;
      12  struct basic_block_def
      13  {
      14    int flags;
      15  };
      16  typedef struct basic_block_def *basic_block;
      17  extern int n_basic_blocks;
      18  extern edge frob ();
      19  basic_block *
      20  find_unreachable_blocks (void)
      21  {
      22    basic_block *tos, *worklist;
      23    tos = worklist = xmalloc (sizeof (basic_block) * n_basic_blocks);
      24    edge e = frob();
      25    if (!(e->dest->flags & 4))
      26      {
      27        e->dest->flags |= 4;
      28        *tos++ = e->dest;
      29      }
      30    return worklist;
      31  }
      32  
      33  /* If the aliasing code does its job properly, then we should be
      34     able to determine that modifying e->dest->flags does not
      35     modify e or e->dest if we can assert strict-aliasing rules.
      36     The net result is that we only need one load of e->dest.  */
      37  /* { dg-final { scan-tree-dump-times "->dest" 1 "cddce1" } } */