1*86d7f5d3SJohn Marino /* mpq_add, mpq_sub -- add or subtract rational numbers.
2*86d7f5d3SJohn Marino
3*86d7f5d3SJohn Marino Copyright 1991, 1994, 1995, 1996, 1997, 2000, 2001, 2004, 2005 Free Software
4*86d7f5d3SJohn Marino Foundation, Inc.
5*86d7f5d3SJohn Marino
6*86d7f5d3SJohn Marino This file is part of the GNU MP Library.
7*86d7f5d3SJohn Marino
8*86d7f5d3SJohn Marino The GNU MP Library is free software; you can redistribute it and/or modify
9*86d7f5d3SJohn Marino it under the terms of the GNU Lesser General Public License as published by
10*86d7f5d3SJohn Marino the Free Software Foundation; either version 3 of the License, or (at your
11*86d7f5d3SJohn Marino option) any later version.
12*86d7f5d3SJohn Marino
13*86d7f5d3SJohn Marino The GNU MP Library is distributed in the hope that it will be useful, but
14*86d7f5d3SJohn Marino WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15*86d7f5d3SJohn Marino or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
16*86d7f5d3SJohn Marino License for more details.
17*86d7f5d3SJohn Marino
18*86d7f5d3SJohn Marino You should have received a copy of the GNU Lesser General Public License
19*86d7f5d3SJohn Marino along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
20*86d7f5d3SJohn Marino
21*86d7f5d3SJohn Marino #include "gmp.h"
22*86d7f5d3SJohn Marino #include "gmp-impl.h"
23*86d7f5d3SJohn Marino
24*86d7f5d3SJohn Marino
25*86d7f5d3SJohn Marino static void __gmpq_aors __GMP_PROTO ((REGPARM_3_1 (mpq_ptr, mpq_srcptr, mpq_srcptr, void (*) __GMP_PROTO ((mpz_ptr, mpz_srcptr, mpz_srcptr))))) REGPARM_ATTR (1);
26*86d7f5d3SJohn Marino #define mpq_aors(w,x,y,fun) __gmpq_aors (REGPARM_3_1 (w, x, y, fun))
27*86d7f5d3SJohn Marino
28*86d7f5d3SJohn Marino REGPARM_ATTR (1) static void
mpq_aors(mpq_ptr rop,mpq_srcptr op1,mpq_srcptr op2,void (* fun)__GMP_PROTO ((mpz_ptr,mpz_srcptr,mpz_srcptr)))29*86d7f5d3SJohn Marino mpq_aors (mpq_ptr rop, mpq_srcptr op1, mpq_srcptr op2,
30*86d7f5d3SJohn Marino void (*fun) __GMP_PROTO ((mpz_ptr, mpz_srcptr, mpz_srcptr)))
31*86d7f5d3SJohn Marino {
32*86d7f5d3SJohn Marino mpz_t gcd;
33*86d7f5d3SJohn Marino mpz_t tmp1, tmp2;
34*86d7f5d3SJohn Marino mp_size_t op1_num_size = ABS (op1->_mp_num._mp_size);
35*86d7f5d3SJohn Marino mp_size_t op1_den_size = op1->_mp_den._mp_size;
36*86d7f5d3SJohn Marino mp_size_t op2_num_size = ABS (op2->_mp_num._mp_size);
37*86d7f5d3SJohn Marino mp_size_t op2_den_size = op2->_mp_den._mp_size;
38*86d7f5d3SJohn Marino TMP_DECL;
39*86d7f5d3SJohn Marino
40*86d7f5d3SJohn Marino TMP_MARK;
41*86d7f5d3SJohn Marino MPZ_TMP_INIT (gcd, MIN (op1_den_size, op2_den_size));
42*86d7f5d3SJohn Marino MPZ_TMP_INIT (tmp1, op1_num_size + op2_den_size);
43*86d7f5d3SJohn Marino MPZ_TMP_INIT (tmp2, op2_num_size + op1_den_size);
44*86d7f5d3SJohn Marino
45*86d7f5d3SJohn Marino /* ROP might be identical to either operand, so don't store the
46*86d7f5d3SJohn Marino result there until we are finished with the input operands. We
47*86d7f5d3SJohn Marino dare to overwrite the numerator of ROP when we are finished
48*86d7f5d3SJohn Marino with the numerators of OP1 and OP2. */
49*86d7f5d3SJohn Marino
50*86d7f5d3SJohn Marino mpz_gcd (gcd, &(op1->_mp_den), &(op2->_mp_den));
51*86d7f5d3SJohn Marino if (! MPZ_EQUAL_1_P (gcd))
52*86d7f5d3SJohn Marino {
53*86d7f5d3SJohn Marino mpz_t t;
54*86d7f5d3SJohn Marino
55*86d7f5d3SJohn Marino mpz_divexact_gcd (tmp1, &(op2->_mp_den), gcd);
56*86d7f5d3SJohn Marino mpz_mul (tmp1, &(op1->_mp_num), tmp1);
57*86d7f5d3SJohn Marino
58*86d7f5d3SJohn Marino mpz_divexact_gcd (tmp2, &(op1->_mp_den), gcd);
59*86d7f5d3SJohn Marino mpz_mul (tmp2, &(op2->_mp_num), tmp2);
60*86d7f5d3SJohn Marino
61*86d7f5d3SJohn Marino MPZ_TMP_INIT (t, MAX (ABS (tmp1->_mp_size), ABS (tmp2->_mp_size)) + 1);
62*86d7f5d3SJohn Marino
63*86d7f5d3SJohn Marino (*fun) (t, tmp1, tmp2);
64*86d7f5d3SJohn Marino mpz_divexact_gcd (tmp2, &(op1->_mp_den), gcd);
65*86d7f5d3SJohn Marino
66*86d7f5d3SJohn Marino mpz_gcd (gcd, t, gcd);
67*86d7f5d3SJohn Marino if (MPZ_EQUAL_1_P (gcd))
68*86d7f5d3SJohn Marino {
69*86d7f5d3SJohn Marino mpz_set (&(rop->_mp_num), t);
70*86d7f5d3SJohn Marino mpz_mul (&(rop->_mp_den), &(op2->_mp_den), tmp2);
71*86d7f5d3SJohn Marino }
72*86d7f5d3SJohn Marino else
73*86d7f5d3SJohn Marino {
74*86d7f5d3SJohn Marino mpz_divexact_gcd (&(rop->_mp_num), t, gcd);
75*86d7f5d3SJohn Marino mpz_divexact_gcd (tmp1, &(op2->_mp_den), gcd);
76*86d7f5d3SJohn Marino mpz_mul (&(rop->_mp_den), tmp1, tmp2);
77*86d7f5d3SJohn Marino }
78*86d7f5d3SJohn Marino }
79*86d7f5d3SJohn Marino else
80*86d7f5d3SJohn Marino {
81*86d7f5d3SJohn Marino /* The common divisor is 1. This is the case (for random input) with
82*86d7f5d3SJohn Marino probability 6/(pi**2), which is about 60.8%. */
83*86d7f5d3SJohn Marino mpz_mul (tmp1, &(op1->_mp_num), &(op2->_mp_den));
84*86d7f5d3SJohn Marino mpz_mul (tmp2, &(op2->_mp_num), &(op1->_mp_den));
85*86d7f5d3SJohn Marino (*fun) (&(rop->_mp_num), tmp1, tmp2);
86*86d7f5d3SJohn Marino mpz_mul (&(rop->_mp_den), &(op1->_mp_den), &(op2->_mp_den));
87*86d7f5d3SJohn Marino }
88*86d7f5d3SJohn Marino TMP_FREE;
89*86d7f5d3SJohn Marino }
90*86d7f5d3SJohn Marino
91*86d7f5d3SJohn Marino
92*86d7f5d3SJohn Marino void
mpq_add(mpq_ptr rop,mpq_srcptr op1,mpq_srcptr op2)93*86d7f5d3SJohn Marino mpq_add (mpq_ptr rop, mpq_srcptr op1, mpq_srcptr op2)
94*86d7f5d3SJohn Marino {
95*86d7f5d3SJohn Marino mpq_aors (rop, op1, op2, mpz_add);
96*86d7f5d3SJohn Marino }
97*86d7f5d3SJohn Marino
98*86d7f5d3SJohn Marino void
mpq_sub(mpq_ptr rop,mpq_srcptr op1,mpq_srcptr op2)99*86d7f5d3SJohn Marino mpq_sub (mpq_ptr rop, mpq_srcptr op1, mpq_srcptr op2)
100*86d7f5d3SJohn Marino {
101*86d7f5d3SJohn Marino mpq_aors (rop, op1, op2, mpz_sub);
102*86d7f5d3SJohn Marino }
103