func CompareInt64(ptr1, ptr2 *int64) int
CompareInt64 is a piecewise function with the following return conditions:
(1) 2, ptr1 != nil AND ptr2 == nil (2) 1, *ptr1 > *ptr2 (3) 0, ptr1 == ptr2 or *ptr1 == *ptr2 (4) -1, *ptr1 < *ptr2 (5) -2, ptr1 == nil AND ptr2 != nil