gcc/testsuite/gcc.dg/torture/pr91445.c

/* { dg-do run } */

struct S { _Bool x; };

void
foo (struct S *s)
{
  __builtin_memset (s, 0x11, sizeof (struct S));
  s->x = 1;
}

int
main ()
{
  struct S s;
  foo (&s);
  char c;
  __builtin_memcpy (&c, &s.x, 1);
  if (c != 1)
    __builtin_abort ();
  return 0;
}