gcc/testsuite/gcc.dg/torture/pr56965-2.c

   1 extern void abort (void);
   2
   3 struct S { int i; int j; };
   4 struct X { struct S s; int k; };
   5 struct Y { int k; struct S s; };
   6 union U { struct X x; struct Y y; } __attribute__((may_alias));
   7
   8 int __attribute__((noinline))
   9 foo (union U *p, union U *q)
  10 {
  11   p->x.s.j = 1;
  12   q->y.s.i = 0;
  13   return p->x.s.j;
  14 }
  15
  16 struct R { int i; int j; } __attribute__((may_alias));
  17
  18 int __attribute__((noinline))
  19 bar (struct R *p, struct R *q)
  20 {
  21   p->i = 1;
  22   q->j = 0;
  23   return p->i;
  24 }
  25
  26 int main()
  27 {
  28   int a[3];
  29   if (foo ((union U *)&a[0], (union U *)&a[0]) != 0)
  30     abort ();
  31   if (bar ((struct R *)&a[1], (struct R *)&a[0]) != 0)
  32     abort ();
  33   return 0;
  34 }