gcc/testsuite/gcc.dg/20100906-1.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2" } */
   3
   4 /* This testcase got misoptimized by combine due to a wrong setting of
   5    subst_low_luid in try_combine.  */
   6
   7 enum rtx_code {
   8   A, B
   9 };
  10
  11 void abort (void);
  12
  13 struct rtx_def {
  14   __extension__ enum rtx_code code:16;
  15 };
  16 typedef struct rtx_def *rtx;
  17
  18 void __attribute__((noinline))
  19 add_constraint (unsigned char is_a)
  20 {
  21   if (is_a)
  22     abort ();
  23 }
  24
  25 void __attribute__((noinline))
  26 foo (rtx defn)
  27 {
  28   switch (defn->code)
  29     {
  30     case A:
  31     case B:
  32       add_constraint (defn->code == A);
  33       break;
  34     default:
  35       break;
  36     }
  37 }
  38
  39 int
  40 main ()
  41 {
  42   struct rtx_def r;
  43
  44   r.code = B;
  45
  46   foo (&r);
  47   return 0;
  48 }