blob: e72563d755ef735e9ae7bfb836cd2bd3b296d1dc (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
|
(* "Hacker's Delight", section 2.12 *)
let ( + ) x y = Int32.(
let z = add x y in
(* Overflow occurs iff x and y have same sign and z's sign is different *)
if logand (logxor z x) (logxor z y) < 0l
then raise Exc.Int32Overflow
else z
)
let ( - ) x y = Int32.(
let z = sub x y in
(* Overflow occurs iff x and y have opposite signs and z and x have
opposite signs *)
if logand (logxor x y) (logxor z x) < 0l
then raise Exc.Int32Overflow
else z
)
let ( * ) x y = Int32.(
let z = mul x y in
if (x = min_int && y < 0l) || (y <> 0l && div z y <> x)
then raise Exc.Int32Overflow
else z
)
let to_int i32 = Int32.(
let i = to_int i32 in
if i32 = of_int i
then i
else raise Exc.IntOverflow
)
let of_int = Int32.of_int
|
