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 the GNU Lesser General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or (at your 10 option) any later version. 11 12 The GNU MP Library is distributed in the hope that it will be useful, but 13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15 License for more details. 16 17 You should have received a copy of the GNU Lesser General Public License 18 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 19 20 #include "gmp.h" 21 #include "gmp-impl.h" 22 #include "longlong.h" 23 24 25 void 26 mpz_lcm_ui (mpz_ptr r, mpz_srcptr u, unsigned long v) 27 { 28 mp_size_t usize; 29 mp_srcptr up; 30 mp_ptr rp; 31 unsigned long g; 32 mp_limb_t c; 33 34 #if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */ 35 if (v > GMP_NUMB_MAX) 36 { 37 mpz_t vz; 38 mp_limb_t vlimbs[2]; 39 vlimbs[0] = v & GMP_NUMB_MASK; 40 vlimbs[1] = v >> GMP_NUMB_BITS; 41 PTR(vz) = vlimbs; 42 SIZ(vz) = 2; 43 mpz_lcm (r, u, vz); 44 return; 45 } 46 #endif 47 48 /* result zero if either operand zero */ 49 usize = SIZ(u); 50 if (usize == 0 || v == 0) 51 { 52 SIZ(r) = 0; 53 return; 54 } 55 usize = ABS(usize); 56 57 MPZ_REALLOC (r, usize+1); 58 59 up = PTR(u); 60 g = (unsigned long) mpn_gcd_1 (up, usize, (mp_limb_t) v); 61 v /= g; 62 63 rp = PTR(r); 64 c = mpn_mul_1 (rp, up, usize, (mp_limb_t) v); 65 rp[usize] = c; 66 usize += (c != 0); 67 SIZ(r) = usize; 68 } 69