gnu/dist/gcc4/gcc/testsuite/gcc.c-torture/execute/builtin-prefetch-5.c

   1 /* Test that __builtin_prefetch does no harm.
   2
   3    Use addresses that are unlikely to be word-aligned.  Some targets
   4    have alignment requirements for prefetch addresses, so make sure the
   5    compiler takes care of that.  This fails if it aborts, anything else
   6    is OK.  */
   7
   8 struct S {
   9   short a;
  10   short b;
  11   char c[8];
  12 } s;
  13
  14 char arr[100];
  15 char *ptr = arr;
  16 int idx = 3;
  17
  18 void
  19 arg_ptr (char *p)
  20 {
  21   __builtin_prefetch (p, 0, 0);
  22 }
  23
  24 void
  25 arg_idx (char *p, int i)
  26 {
  27   __builtin_prefetch (&p[i], 0, 0);
  28 }
  29
  30 void
  31 glob_ptr (void)
  32 {
  33   __builtin_prefetch (ptr, 0, 0);
  34 }
  35
  36 void
  37 glob_idx (void)
  38 {
  39   __builtin_prefetch (&ptr[idx], 0, 0);
  40 }
  41
  42 int
  43 main ()
  44 {
  45   __builtin_prefetch (&s.b, 0, 0);
  46   __builtin_prefetch (&s.c[1], 0, 0);
  47
  48   arg_ptr (&s.c[1]);
  49   arg_ptr (ptr+3);
  50   arg_idx (ptr, 3);
  51   arg_idx (ptr+1, 2);
  52   idx = 3;
  53   glob_ptr ();
  54   glob_idx ();
  55   ptr++;
  56   idx = 2;
  57   glob_ptr ();
  58   glob_idx ();
  59   exit (0);
  60 }