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
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
export function swap32(val: number): number {  return (    ((val & 0xff) << 24) |    ((val & 0xff00) << 8) |    ((val >> 8) & 0xff00) |    ((val >> 24) & 0xff)  );}
function n16(n: number): number {  return n & 0xffff;}
function n32(n: number): number {  return n >>> 0;}
function add32WithCarry(a: number, b: number): [number, number] {  const added = n32(a) + n32(b);  return [n32(added), added > 0xffffffff ? 1 : 0];}
function mul32WithCarry(a: number, b: number): [number, number] {  const al = n16(a);  const ah = n16(a >>> 16);  const bl = n16(b);  const bh = n16(b >>> 16);
  const [t, tc] = add32WithCarry(al * bh, ah * bl);  const [n, nc] = add32WithCarry(al * bl, n32(t << 16));  const carry = nc + (tc << 16) + n16(t >>> 16) + ah * bh;
  return [n, carry];}
/** * mul32 performs 32-bit multiplication, a * b * @param a * @param b */export function mul32(a: number, b: number): number {  // https://stackoverflow.com/a/28151933  const al = n16(a);  const ah = a - al;  return n32(n32(ah * b) + al * b);}
/** * mul64 performs 64-bit multiplication with two 32-bit words * @param [ah, al] * @param [bh, bl] */export function mul64(  [ah, al]: [number, number],  [bh, bl]: [number, number],): [number, number] {  const [n, c] = mul32WithCarry(al, bl);  return [n32(mul32(al, bh) + mul32(ah, bl) + c), n];}