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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: }