| Austin Schuh | bb1338c | 2024-06-15 19:31:16 -0700 | [diff] [blame] | 1 | /* mpz_lcm_ui -- least common multiple of mpz and ulong. |
| 2 | |
| 3 | Copyright 2001, 2002, 2004 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of the GNU MP Library. |
| 6 | |
| 7 | The GNU MP Library is free software; you can redistribute it and/or modify |
| 8 | it under the terms of either: |
| 9 | |
| 10 | * the GNU Lesser General Public License as published by the Free |
| 11 | Software Foundation; either version 3 of the License, or (at your |
| 12 | option) any later version. |
| 13 | |
| 14 | or |
| 15 | |
| 16 | * the GNU General Public License as published by the Free Software |
| 17 | Foundation; either version 2 of the License, or (at your option) any |
| 18 | later version. |
| 19 | |
| 20 | or both in parallel, as here. |
| 21 | |
| 22 | The GNU MP Library is distributed in the hope that it will be useful, but |
| 23 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 24 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 25 | for more details. |
| 26 | |
| 27 | You should have received copies of the GNU General Public License and the |
| 28 | GNU Lesser General Public License along with the GNU MP Library. If not, |
| 29 | see https://www.gnu.org/licenses/. */ |
| 30 | |
| 31 | #include "gmp-impl.h" |
| 32 | #include "longlong.h" |
| 33 | |
| 34 | |
| 35 | void |
| 36 | mpz_lcm_ui (mpz_ptr r, mpz_srcptr u, unsigned long v) |
| 37 | { |
| 38 | mp_size_t usize; |
| 39 | mp_srcptr up; |
| 40 | mp_ptr rp; |
| 41 | unsigned long g; |
| 42 | mp_limb_t c; |
| 43 | |
| 44 | #if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */ |
| 45 | if (v > GMP_NUMB_MAX) |
| 46 | { |
| 47 | mpz_t vz; |
| 48 | mp_limb_t vlimbs[2]; |
| 49 | vlimbs[0] = v & GMP_NUMB_MASK; |
| 50 | vlimbs[1] = v >> GMP_NUMB_BITS; |
| 51 | PTR(vz) = vlimbs; |
| 52 | SIZ(vz) = 2; |
| 53 | mpz_lcm (r, u, vz); |
| 54 | return; |
| 55 | } |
| 56 | #endif |
| 57 | |
| 58 | /* result zero if either operand zero */ |
| 59 | usize = SIZ(u); |
| 60 | if (usize == 0 || v == 0) |
| 61 | { |
| 62 | SIZ(r) = 0; |
| 63 | return; |
| 64 | } |
| 65 | usize = ABS(usize); |
| 66 | |
| 67 | MPZ_REALLOC (r, usize+1); |
| 68 | |
| 69 | up = PTR(u); |
| 70 | g = (unsigned long) mpn_gcd_1 (up, usize, (mp_limb_t) v); |
| 71 | v /= g; |
| 72 | |
| 73 | rp = PTR(r); |
| 74 | c = mpn_mul_1 (rp, up, usize, (mp_limb_t) v); |
| 75 | rp[usize] = c; |
| 76 | usize += (c != 0); |
| 77 | SIZ(r) = usize; |
| 78 | } |