1struct s {
2  unsigned long long a:8, b:32;
3};
4
5struct s
6f(struct s x)
7{
8  x.b = 0xcdef1234;
9  return x;
10}
11
12main()
13{
14  static struct s i;
15  i.a = 12;
16  i = f(i);
17  if (i.a != 12 || i.b != 0xcdef1234)
18    abort();
19  exit(0);
20}
21