1/*	$NetBSD: bn_mp_lcm.c,v 1.2 2017/01/28 21:31:47 christos Exp $	*/
2
3#include <tommath.h>
4#ifdef BN_MP_LCM_C
5/* LibTomMath, multiple-precision integer library -- Tom St Denis
6 *
7 * LibTomMath is a library that provides multiple-precision
8 * integer arithmetic as well as number theoretic functionality.
9 *
10 * The library was designed directly after the MPI library by
11 * Michael Fromberger but has been written from scratch with
12 * additional optimizations in place.
13 *
14 * The library is free for all purposes without any express
15 * guarantee it works.
16 *
17 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
18 */
19
20/* computes least common multiple as |a*b|/(a, b) */
21int mp_lcm (mp_int * a, mp_int * b, mp_int * c)
22{
23  int     res;
24  mp_int  t1, t2;
25
26
27  if ((res = mp_init_multi (&t1, &t2, NULL)) != MP_OKAY) {
28    return res;
29  }
30
31  /* t1 = get the GCD of the two inputs */
32  if ((res = mp_gcd (a, b, &t1)) != MP_OKAY) {
33    goto LBL_T;
34  }
35
36  /* divide the smallest by the GCD */
37  if (mp_cmp_mag(a, b) == MP_LT) {
38     /* store quotient in t2 such that t2 * b is the LCM */
39     if ((res = mp_div(a, &t1, &t2, NULL)) != MP_OKAY) {
40        goto LBL_T;
41     }
42     res = mp_mul(b, &t2, c);
43  } else {
44     /* store quotient in t2 such that t2 * a is the LCM */
45     if ((res = mp_div(b, &t1, &t2, NULL)) != MP_OKAY) {
46        goto LBL_T;
47     }
48     res = mp_mul(a, &t2, c);
49  }
50
51  /* fix the sign to positive */
52  c->sign = MP_ZPOS;
53
54LBL_T:
55  mp_clear_multi (&t1, &t2, NULL);
56  return res;
57}
58#endif
59
60/* Source: /cvs/libtom/libtommath/bn_mp_lcm.c,v  */
61/* Revision: 1.4  */
62/* Date: 2006/12/28 01:25:13  */
63