Return to div.c CVS log

Up to [local] / OpenXM_contrib / gmp / mpq

Annotation of OpenXM_contrib/gmp/mpq/div.c, Revision 1.1.1.3

1.1       maekawa     1: /* mpq_div -- divide two rational numbers.
                      2:
1.1.1.3 ! ohara       3: Copyright 1991, 1994, 1995, 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
1.1.1.2   maekawa     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
1.1       maekawa    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
1.1.1.2   maekawa    14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1.1       maekawa    15: License for more details.
                     16:
1.1.1.2   maekawa    17: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    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:
1.1.1.3 ! ohara      25:
1.1       maekawa    26: void
                     27: mpq_div (mpq_ptr quot, mpq_srcptr op1, mpq_srcptr op2)
                     28: {
                     29:   mpz_t gcd1, gcd2;
                     30:   mpz_t tmp1, tmp2;
                     31:   mpz_t numtmp;
1.1.1.2   maekawa    32:
                     33:   if (op2->_mp_num._mp_size == 0)
                     34:     DIVIDE_BY_ZERO;
1.1       maekawa    35:
                     36:   mpz_init (gcd1);
                     37:   mpz_init (gcd2);
                     38:   mpz_init (tmp1);
                     39:   mpz_init (tmp2);
                     40:   mpz_init (numtmp);
                     41:
                     42:   /* QUOT might be identical to either operand, so don't store the
                     43:      result there until we are finished with the input operands.  We
                     44:      dare to overwrite the numerator of QUOT when we are finished
                     45:      with the numerators of OP1 and OP2.  */
                     46:
                     47:   mpz_gcd (gcd1, &(op1->_mp_num), &(op2->_mp_num));
                     48:   mpz_gcd (gcd2, &(op2->_mp_den), &(op1->_mp_den));
                     49:
1.1.1.3 ! ohara      50:   mpz_divexact_gcd (tmp1, &(op1->_mp_num), gcd1);
        !            51:   mpz_divexact_gcd (tmp2, &(op2->_mp_den), gcd2);
1.1       maekawa    52:
                     53:   mpz_mul (numtmp, tmp1, tmp2);
                     54:
1.1.1.3 ! ohara      55:   mpz_divexact_gcd (tmp1, &(op2->_mp_num), gcd1);
        !            56:   mpz_divexact_gcd (tmp2, &(op1->_mp_den), gcd2);
1.1       maekawa    57:
                     58:   mpz_mul (&(quot->_mp_den), tmp1, tmp2);
                     59:
                     60:   /* We needed to go via NUMTMP to take care of QUOT being the same
                     61:      as either input operands.  Now move NUMTMP to QUOT->_mp_num.  */
                     62:   mpz_set (&(quot->_mp_num), numtmp);
                     63:
                     64:   /* Keep the denominator positive.  */
                     65:   if (quot->_mp_den._mp_size < 0)
                     66:     {
                     67:       quot->_mp_den._mp_size = -quot->_mp_den._mp_size;
                     68:       quot->_mp_num._mp_size = -quot->_mp_num._mp_size;
                     69:     }
                     70:
                     71:   mpz_clear (numtmp);
                     72:   mpz_clear (tmp2);
                     73:   mpz_clear (tmp1);
                     74:   mpz_clear (gcd2);
                     75:   mpz_clear (gcd1);
                     76: }