## File: bn_mp_lcm.c

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libtommath 1.1.0-3
 `123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657` ``````#include "tommath_private.h" #ifdef BN_MP_LCM_C /* 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. * * SPDX-License-Identifier: Unlicense */ /* computes least common multiple as |a*b|/(a, b) */ int mp_lcm(const mp_int *a, const 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 LBL_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 LBL_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 LBL_T; } res = mp_mul(a, &t2, c); } /* fix the sign to positive */ c->sign = MP_ZPOS; LBL_T: mp_clear_multi(&t1, &t2, NULL); return res; } #endif /* ref: HEAD -> master, tag: v1.1.0 */ /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ /* commit time: 2019-01-28 20:32:32 +0100 */ ``````