gcc/testsuite/gcc.dg/torture/alias-1.c

   1 /* { dg-do run } */
   2 /* { dg-options "-fschedule-insns" } */
   3 /* { dg-require-effective-target scheduling } */
   4
   5 extern void abort (void) __attribute__((noreturn));
   6
   7 struct B { int a; int b;};
   8 struct wrapper {
   9 union setconflict
  10 {
  11   struct S { char one1; struct B b1; } s;
  12   struct T { struct B b2; char two2; } t;
  13 } a;
  14 };
  15
  16 int
  17 main ()
  18 {
  19   int sum = 0;
  20   int i;
  21   struct wrapper w;
  22   struct B *p;
  23
  24   p = &w.a.s.b1;
  25   asm ("": "=r" (p):"0" (p));
  26   p->a = 0;
  27   asm ("": "=r" (p):"0" (p));
  28   sum += p->a;
  29
  30   p = &w.a.t.b2;
  31   asm ("": "=r" (p):"0" (p));
  32   p->b = 1;
  33   asm ("": "=r" (p):"0" (p));
  34   sum += p->b;
  35
  36   if (sum != 1)
  37     abort();
  38   return 0;
  39 }