1  /* { dg-do compile } */
       2  /* { dg-options "-O1 -fno-tree-fre -fdump-tree-dom2" } */
       3  
       4  extern void abort (void);
       5  union tree_node;
       6  typedef union tree_node *tree;
       7  enum tree_code
       8  {
       9    LAST_AND_UNUSED_TREE_CODE
      10  };
      11  extern const char tree_code_type[];
      12  struct tree_common
      13  {
      14    enum tree_code code:8;
      15  };
      16  struct tree_type
      17  {
      18    struct tree_common common;
      19    double alias_set;
      20  };
      21  union tree_node
      22  {
      23    struct tree_common common;
      24    struct tree_type type;
      25  };
      26  long
      27  foo (t, set)
      28       tree t;
      29       double set;
      30  {
      31    if (tree_code_type[t->common.code] != 't')
      32      abort ();
      33  
      34    t->type.alias_set = set;
      35  
      36    if (t->common.code == 42)
      37      return 1;
      38    else
      39      return 0;
      40  }
      41  /* There should be precisely one load of common.code.  If there is
      42     more than one, then the dominator optimizations failed.  */
      43  /* { dg-final { scan-tree-dump-times "common.code" 1 "dom2" } } */