func1: pointer_type ptr1, pointer_type ptr2, 
test17.c: In function 'func2':
test17.c:18:14: warning: comparison between pointer and integer
     if (ptr1 == (123, 0))
              ^
func2: pointer_type ptr1, pointer_type ptr2, 
test17.c: In function 'func3':
test17.c:26:14: warning: comparison between pointer and integer
     if (ptr1 != (123, 0))
              ^
func3: pointer_type ptr1, pointer_type ptr2, 
func4: pointer_type ptr1, pointer_type ptr2, 
func5: pointer_type ptr1, pointer_type ptr2,