1 /*
2 Copyright (C) 2010 Sebastian Pancratz
3
4 This file is part of FLINT.
5
6 FLINT is free software: you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version. See <http://www.gnu.org/licenses/>.
10 */
11
12 #include <gmp.h>
13 #include "flint.h"
14 #include "fmpz.h"
15 #include "fmpz_vec.h"
16 #include "fmpq_poly.h"
17
_fmpq_poly_add_can(fmpz * rpoly,fmpz_t rden,const fmpz * poly1,const fmpz_t den1,slong len1,const fmpz * poly2,const fmpz_t den2,slong len2,int can)18 void _fmpq_poly_add_can(fmpz * rpoly, fmpz_t rden,
19 const fmpz * poly1, const fmpz_t den1, slong len1,
20 const fmpz * poly2, const fmpz_t den2, slong len2, int can)
21 {
22 slong max = FLINT_MAX(len1, len2);
23 slong min = FLINT_MIN(len1, len2);
24
25 fmpz_t d;
26
27 if (fmpz_equal(den1, den2))
28 {
29 _fmpz_poly_add(rpoly, poly1, len1, poly2, len2);
30
31 if (fmpz_is_one(den1) || !can)
32 fmpz_set(rden, den1);
33 else
34 {
35 fmpz_init(d);
36 _fmpz_vec_content(d, rpoly, max);
37
38 if (!fmpz_is_one(d))
39 fmpz_gcd(d, d, den1);
40
41 if (fmpz_is_one(d))
42 fmpz_set(rden, den1);
43 else
44 {
45 _fmpz_vec_scalar_divexact_fmpz(rpoly, rpoly, max, d);
46 fmpz_divexact(rden, den1, d);
47 }
48
49 fmpz_clear(d);
50 }
51
52 return;
53 }
54
55 fmpz_init(d);
56 fmpz_one(d);
57 if (!fmpz_is_one(den1) && !fmpz_is_one(den2))
58 fmpz_gcd(d, den1, den2);
59
60 if (fmpz_is_one(d))
61 {
62 _fmpz_vec_scalar_mul_fmpz(rpoly, poly1, len1, den2);
63 _fmpz_vec_scalar_addmul_fmpz(rpoly, poly2, min, den1);
64 if (len1 < len2)
65 _fmpz_vec_scalar_mul_fmpz(rpoly + min, poly2 + min, max - min, den1);
66 fmpz_mul(rden, den1, den2);
67 }
68 else
69 {
70 fmpz_t den11;
71 fmpz_t den22;
72 fmpz_init(den11);
73 fmpz_init(den22);
74 fmpz_divexact(den11, den1, d);
75 fmpz_divexact(den22, den2, d);
76
77 _fmpz_vec_scalar_mul_fmpz(rpoly, poly1, len1, den22);
78 _fmpz_vec_scalar_addmul_fmpz(rpoly, poly2, len2, den11);
79 if (len1 < len2)
80 _fmpz_vec_scalar_mul_fmpz(rpoly + min, poly2 + min, max - min, den11);
81
82 if (_fmpz_vec_is_zero(rpoly, max))
83 fmpz_one(rden);
84 else
85 {
86 if (can)
87 {
88 fmpz_t e;
89 fmpz_init(e);
90 _fmpz_vec_content(e, rpoly, max);
91 if (!fmpz_is_one(e))
92 fmpz_gcd(e, e, d);
93
94 if (fmpz_is_one(e))
95 fmpz_mul(rden, den1, den22);
96 else
97 {
98 _fmpz_vec_scalar_divexact_fmpz(rpoly, rpoly, max, e);
99 fmpz_divexact(den11, den1, e);
100 fmpz_mul(rden, den11, den22);
101 }
102 fmpz_clear(e);
103 } else
104 fmpz_mul(rden, den1, den22);
105 }
106 fmpz_clear(den11);
107 fmpz_clear(den22);
108 }
109 fmpz_clear(d);
110 }
111
_fmpq_poly_add(fmpz * rpoly,fmpz_t rden,const fmpz * poly1,const fmpz_t den1,slong len1,const fmpz * poly2,const fmpz_t den2,slong len2)112 void _fmpq_poly_add(fmpz * rpoly, fmpz_t rden,
113 const fmpz * poly1, const fmpz_t den1, slong len1,
114 const fmpz * poly2, const fmpz_t den2, slong len2)
115 {
116 _fmpq_poly_add_can(rpoly, rden, poly1, den1, len1, poly2, den2, len2, 1);
117 }
118
fmpq_poly_add_can(fmpq_poly_t res,const fmpq_poly_t poly1,const fmpq_poly_t poly2,int can)119 void fmpq_poly_add_can(fmpq_poly_t res, const fmpq_poly_t poly1,
120 const fmpq_poly_t poly2, int can)
121 {
122 slong len1 = poly1->length, len2, max;
123
124 if (poly1 == poly2) /* Set res = 2 * poly1 */
125 {
126 fmpq_poly_fit_length(res, len1);
127 _fmpq_poly_set_length(res, len1);
128
129 if (fmpz_is_even(poly1->den))
130 {
131 _fmpz_vec_set(res->coeffs, poly1->coeffs, len1);
132 fmpz_fdiv_q_2exp(res->den, poly1->den, 1);
133 }
134 else
135 {
136 _fmpz_vec_scalar_mul_2exp(res->coeffs, poly1->coeffs, len1, 1);
137 fmpz_set(res->den, poly1->den);
138 }
139 return;
140 }
141
142 len2 = poly2->length;
143 max = FLINT_MAX(len1, len2);
144 fmpq_poly_fit_length(res, max);
145
146 if (res != poly2)
147 _fmpq_poly_add_can(res->coeffs, res->den,
148 poly1->coeffs, poly1->den, len1,
149 poly2->coeffs, poly2->den, len2, can);
150 else
151 _fmpq_poly_add_can(res->coeffs, res->den,
152 poly2->coeffs, poly2->den, len2,
153 poly1->coeffs, poly1->den, len1, can);
154
155 _fmpq_poly_set_length(res, max);
156 _fmpq_poly_normalise(res);
157 }
158
fmpq_poly_add(fmpq_poly_t res,const fmpq_poly_t poly1,const fmpq_poly_t poly2)159 void fmpq_poly_add(fmpq_poly_t res, const fmpq_poly_t poly1,
160 const fmpq_poly_t poly2)
161 {
162 fmpq_poly_add_can(res, poly1, poly2, 1);
163 }
164
165