Annotation of OpenXM_contrib/gmp/mpz/lcm.c, Revision 1.1.1.3
1.1.1.3 ! ohara 1: /* mpz_lcm -- mpz/mpz least common multiple.
1.1 maekawa 2:
1.1.1.3 ! ohara 3: Copyright 1996, 2000, 2001 Free Software Foundation, Inc.
1.1 maekawa 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 2.1 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; see the file COPYING.LIB. If not, write to
19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
20: MA 02111-1307, USA. */
21:
22: #include "gmp.h"
23: #include "gmp-impl.h"
24: #include "longlong.h"
25:
26:
27: void
28: mpz_lcm (mpz_ptr r, mpz_srcptr u, mpz_srcptr v)
29: {
30: mpz_t g;
31: mp_size_t usize, vsize, size;
1.1.1.2 maekawa 32: TMP_DECL (marker);
33:
1.1.1.3 ! ohara 34: usize = SIZ (u);
! 35: vsize = SIZ (v);
1.1 maekawa 36: if (usize == 0 || vsize == 0)
37: {
38: SIZ (r) = 0;
39: return;
40: }
1.1.1.3 ! ohara 41: usize = ABS (usize);
! 42: vsize = ABS (vsize);
! 43:
! 44: if (vsize == 1)
! 45: {
! 46: mp_limb_t vl, gl, c;
! 47: mp_srcptr up;
! 48: mp_ptr rp;
! 49:
! 50: one:
! 51: MPZ_REALLOC (r, usize+1);
! 52:
! 53: up = PTR(u);
! 54: vl = PTR(v)[0];
! 55: gl = mpn_gcd_1 (up, usize, vl);
! 56: vl /= gl;
! 57:
! 58: rp = PTR(r);
! 59: c = mpn_mul_1 (rp, up, usize, vl);
! 60: rp[usize] = c;
! 61: usize += (c != 0);
! 62: SIZ(r) = usize;
! 63: return;
! 64: }
! 65:
! 66: if (usize == 1)
! 67: {
! 68: usize = vsize;
! 69: MPZ_SRCPTR_SWAP (u, v);
! 70: goto one;
! 71: }
1.1 maekawa 72:
1.1.1.3 ! ohara 73: TMP_MARK (marker);
1.1 maekawa 74: size = MAX (usize, vsize);
75: MPZ_TMP_INIT (g, size);
76:
77: mpz_gcd (g, u, v);
78: mpz_divexact (g, u, g);
79: mpz_mul (r, g, v);
1.1.1.3 ! ohara 80:
! 81: SIZ (r) = ABS (SIZ (r)); /* result always positive */
1.1.1.2 maekawa 82:
83: TMP_FREE (marker);
1.1 maekawa 84: }
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