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Annotation of OpenXM_contrib/gmp/mpz/lcm_ui.c, Revision 1.1.1.1

1.1       ohara       1: /* mpz_lcm_ui -- least common multiple of mpz and ulong.
                      2:
                      3: Copyright 2001, 2002 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 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_ui (mpz_ptr r, mpz_srcptr u, unsigned long v)
                     29: {
                     30:   mp_size_t      usize;
                     31:   mp_srcptr      up;
                     32:   mp_ptr         rp;
                     33:   unsigned long  g;
                     34:   mp_limb_t      c;
                     35:
                     36: #if GMP_NAIL_BITS != 0
                     37:   if (v > GMP_NUMB_MAX)
                     38:     {
                     39:       mpz_t vz;
                     40:       mp_limb_t vlimbs[2];
                     41:       vlimbs[0] = v & GMP_NUMB_MASK;
                     42:       vlimbs[1] = v >> GMP_NUMB_BITS;
                     43:       PTR(vz) = vlimbs;
                     44:       SIZ(vz) = 2;
                     45:       mpz_lcm (r, u, vz);
                     46:       return;
                     47:     }
                     48: #endif
                     49:
                     50:   /* result zero if either operand zero */
                     51:   usize = SIZ(u);
                     52:   if (usize == 0 || v == 0)
                     53:     {
                     54:       SIZ(r) = 0;
                     55:       return;
                     56:     }
                     57:   usize = ABS(usize);
                     58:
                     59:   MPZ_REALLOC (r, usize+1);
                     60:
                     61:   up = PTR(u);
                     62:   g = (unsigned long) mpn_gcd_1 (up, usize, (mp_limb_t) v);
                     63:   v /= g;
                     64:
                     65:   rp = PTR(r);
                     66:   c = mpn_mul_1 (rp, up, usize, (mp_limb_t) v);
                     67:   rp[usize] = c;
                     68:   usize += (c != 0);
                     69:   SIZ(r) = usize;
                     70: }