gcc/testsuite/gcc.dg/store_merging_19.c

   1 /* PR tree-optimization/83843 */
   2 /* { dg-do run } */
   3 /* { dg-options "-O2 -fdump-tree-store-merging" } */
   4 /* { dg-final { scan-tree-dump-times "Merging successful" 3 "store-merging" { target store_merge } } } */
   5
   6 __attribute__((noipa)) void
   7 foo (unsigned char *buf, unsigned char *tab)
   8 {
   9   tab = __builtin_assume_aligned (tab, 2);
  10   buf = __builtin_assume_aligned (buf, 2);
  11   unsigned v = tab[1] ^ (tab[0] << 8);
  12   buf[0] = ~(v >> 8);
  13   buf[1] = ~v;
  14 }
  15
  16 __attribute__((noipa)) void
  17 bar (unsigned char *buf, unsigned char *tab)
  18 {
  19   tab = __builtin_assume_aligned (tab, 2);
  20   buf = __builtin_assume_aligned (buf, 2);
  21   unsigned v = tab[1] ^ (tab[0] << 8);
  22   buf[0] = (v >> 8);
  23   buf[1] = ~v;
  24 }
  25
  26 __attribute__((noipa)) void
  27 baz (unsigned char *buf, unsigned char *tab)
  28 {
  29   tab = __builtin_assume_aligned (tab, 2);
  30   buf = __builtin_assume_aligned (buf, 2);
  31   unsigned v = tab[1] ^ (tab[0] << 8);
  32   buf[0] = ~(v >> 8);
  33   buf[1] = v;
  34 }
  35
  36 int
  37 main ()
  38 {
  39   volatile unsigned char l1 = 0;
  40   volatile unsigned char l2 = 1;
  41   unsigned char buf[2] __attribute__((aligned (2)));
  42   unsigned char tab[2] __attribute__((aligned (2))) = { l1 + 1, l2 * 2 };
  43   foo (buf, tab);
  44   if (buf[0] != (unsigned char) ~1 || buf[1] != (unsigned char) ~2)
  45     __builtin_abort ();
  46   buf[0] = l1 + 7;
  47   buf[1] = l2 * 8;
  48   bar (buf, tab);
  49   if (buf[0] != 1 || buf[1] != (unsigned char) ~2)
  50     __builtin_abort ();
  51   buf[0] = l1 + 9;
  52   buf[1] = l2 * 10;
  53   baz (buf, tab);
  54   if (buf[0] != (unsigned char) ~1 || buf[1] != 2)
  55     __builtin_abort ();
  56   return 0;
  57 }