/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is a library that provides multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library was designed directly after the MPI library by
* Michael Fromberger but has been written from scratch with
* additional optimizations in place.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
*/
#include <tommath.h>
/* computes least common multiple as |a*b|/(a, b) */
int mp_lcm (mp_int * a, mp_int * b, mp_int * c)
{
int res;
mp_int t1, t2;
if ((res = mp_init_multi (&t1, &t2, NULL)) != MP_OKAY) {
return res;
}
/* t1 = get the GCD of the two inputs */
if ((res = mp_gcd (a, b, &t1)) != MP_OKAY) {
goto __T;
}
/* divide the smallest by the GCD */
if (mp_cmp_mag(a, b) == MP_LT) {
/* store quotient in t2 such that t2 * b is the LCM */
if ((res = mp_div(a, &t1, &t2, NULL)) != MP_OKAY) {
goto __T;
}
res = mp_mul(b, &t2, c);
} else {
/* store quotient in t2 such that t2 * a is the LCM */
if ((res = mp_div(b, &t1, &t2, NULL)) != MP_OKAY) {
goto __T;
}
res = mp_mul(a, &t2, c);
}
/* fix the sign to positive */
c->sign = MP_ZPOS;
__T:
mp_clear_multi (&t1, &t2, NULL);
return res;
}
