gcc/testsuite/gcc.dg/store_merging_2.c

   1 /* { dg-do run } */
   2 /* { dg-require-effective-target store_merge } */
   3 /* { dg-options "-O2 -fdump-tree-store-merging" } */
   4
   5 struct bar
   6 {
   7   int a;
   8   unsigned char b;
   9   unsigned char c;
  10   short d;
  11   unsigned char e;
  12   unsigned char f;
  13   unsigned char g;
  14 };
  15
  16 __attribute__ ((noinline)) void
  17 foozero (struct bar *p)
  18 {
  19   p->b = 0;
  20   p->a = 0;
  21   p->c = 0;
  22   p->d = 0;
  23   p->e = 0;
  24   p->f = 0;
  25   p->g = 0;
  26 }
  27
  28 __attribute__ ((noinline)) void
  29 foo1 (struct bar *p)
  30 {
  31   p->b = 1;
  32   p->a = 2;
  33   p->c = 3;
  34   p->d = 4;
  35   p->e = 5;
  36   p->f = 0;
  37   p->g = 0xff;
  38 }
  39
  40 __attribute__ ((noinline)) void
  41 foo2 (struct bar *p, struct bar *p2)
  42 {
  43   p->b = 0xff;
  44   p2->b = 0xa;
  45   p->a = 0xfffff;
  46   p2->c = 0xc;
  47   p->c = 0xff;
  48   p2->d = 0xbf;
  49   p->d = 0xfff;
  50 }
  51
  52 int
  53 main (void)
  54 {
  55   struct bar b1, b2;
  56   foozero (&b1);
  57   foozero (&b2);
  58
  59   foo1 (&b1);
  60   if (b1.b != 1 || b1.a != 2 || b1.c != 3 || b1.d != 4 || b1.e != 5
  61       || b1.f != 0 || b1.g != 0xff)
  62     __builtin_abort ();
  63
  64   foozero (&b1);
  65   /* Make sure writes to aliasing struct pointers preserve the
  66      correct order.  */
  67   foo2 (&b1, &b1);
  68   if (b1.b != 0xa || b1.a != 0xfffff || b1.c != 0xff || b1.d != 0xfff)
  69     __builtin_abort ();
  70
  71   foozero (&b1);
  72   foo2 (&b1, &b2);
  73   if (b1.a != 0xfffff || b1.b != 0xff || b1.c != 0xff || b1.d != 0xfff
  74       || b2.b != 0xa || b2.c != 0xc || b2.d != 0xbf)
  75     __builtin_abort ();
  76
  77   return 0;
  78 }
  79
  80 /* { dg-final { scan-tree-dump-times "Merging successful" 2 "store-merging" } } */