1 /*
2 Copyright (C) 2011 Fredrik Johansson
3 Copyright (C) 2012 Lina Kulakova
4 Copyright (C) 2013 Mike Hansen
5
6 This file is part of FLINT.
7
8 FLINT is free software: you can redistribute it and/or modify it under
9 the terms of the GNU Lesser General Public License (LGPL) as published
10 by the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version. See <http://www.gnu.org/licenses/>.
12 */
13
14 #ifdef T
15
16 #include "templates.h"
17
18 #include <gmp.h>
19 #include "flint.h"
20 #include "ulong_extras.h"
21 void
_TEMPLATE(T,poly_compose_mod_horner_preinv)22 _TEMPLATE(T, poly_compose_mod_horner_preinv) (
23 TEMPLATE(T, struct) * res,
24 const TEMPLATE(T, struct) * f, slong lenf,
25 const TEMPLATE(T, struct) * g,
26 const TEMPLATE(T, struct) * h, slong lenh,
27 const TEMPLATE(T, struct) * hinv, slong lenhinv,
28 const TEMPLATE(T, ctx_t) ctx)
29 {
30 slong i, len;
31 TEMPLATE(T, struct) * t;
32
33 if (lenh == 1)
34 return;
35
36 if (lenf == 1)
37 {
38 TEMPLATE(T, set) (res, f, ctx);
39 return;
40 }
41
42 if (lenh == 2)
43 {
44 _TEMPLATE(T, TEMPLATE(poly_evaluate, T)) (res, f, lenf, g, ctx);
45 return;
46 }
47
48 len = lenh - 1;
49 i = lenf - 1;
50 t = _TEMPLATE(T, vec_init) (2 * lenh - 3, ctx);
51
52 _TEMPLATE(T, TEMPLATE(poly_scalar_mul, T)) (res, g, len, f + i, ctx);
53 i--;
54 if (i >= 0)
55 {
56 TEMPLATE(T, add) (res, res, f + i, ctx);
57 }
58
59 while (i > 0)
60 {
61 i--;
62 _TEMPLATE(T, poly_mulmod_preinv) (t, res, len, g, len, h, lenh, hinv,
63 lenhinv, ctx);
64 _TEMPLATE(T, poly_add) (res, t, len, f + i, 1, ctx);
65 }
66
67 _TEMPLATE(T, vec_clear) (t, 2 * lenh - 3, ctx);
68 }
69
70 void
TEMPLATE(T,poly_compose_mod_horner_preinv)71 TEMPLATE(T, poly_compose_mod_horner_preinv) (
72 TEMPLATE(T, poly_t) res,
73 const TEMPLATE(T, poly_t) poly1,
74 const TEMPLATE(T, poly_t) poly2,
75 const TEMPLATE(T, poly_t) poly3,
76 const TEMPLATE(T, poly_t) poly3inv,
77 const TEMPLATE(T, ctx_t) ctx)
78 {
79 TEMPLATE(T, t) inv3;
80 slong len1 = poly1->length;
81 slong len2 = poly2->length;
82 slong len3 = poly3->length;
83 slong len3inv = poly3inv->length;
84 slong len = len3 - 1;
85 slong vec_len = FLINT_MAX(len3 - 1, len2);
86
87 TEMPLATE(T, struct) * ptr2;
88
89 if (len3 == 0)
90 {
91 TEMPLATE_PRINTF
92 ("Exception: division by zero in %s_poly_compose_mod_horner\n", T);
93 flint_abort();
94 }
95
96 if (len1 == 0 || len3 == 1)
97 {
98 TEMPLATE(T, poly_zero) (res, ctx);
99 return;
100 }
101
102 if (len1 == 1)
103 {
104 TEMPLATE(T, poly_set) (res, poly1, ctx);
105 return;
106 }
107
108 if (res == poly3 || res == poly1)
109 {
110 TEMPLATE(T, poly_t) tmp;
111 TEMPLATE(T, poly_init) (tmp, ctx);
112 TEMPLATE(T, poly_compose_mod_horner_preinv) (tmp, poly1, poly2, poly3,
113 poly3inv, ctx);
114 TEMPLATE(T, poly_swap) (tmp, res, ctx);
115 TEMPLATE(T, poly_clear) (tmp, ctx);
116 return;
117 }
118
119 ptr2 = _TEMPLATE(T, vec_init) (vec_len, ctx);
120
121 if (len2 <= len3 - 1)
122 {
123 _TEMPLATE(T, vec_set) (ptr2, poly2->coeffs, len2, ctx);
124 _TEMPLATE(T, vec_zero) (ptr2 + len2, vec_len - len2, ctx);
125 }
126 else
127 {
128 TEMPLATE(T, init) (inv3, ctx);
129 TEMPLATE(T, inv) (inv3, poly3->coeffs + len, ctx);
130 _TEMPLATE(T, poly_rem) (ptr2, poly2->coeffs, len2,
131 poly3->coeffs, len3, inv3, ctx);
132 TEMPLATE(T, clear) (inv3, ctx);
133 }
134
135 TEMPLATE(T, poly_fit_length) (res, len, ctx);
136 _TEMPLATE(T, poly_compose_mod_horner_preinv) (res->coeffs,
137 poly1->coeffs, len1,
138 ptr2,
139 poly3->coeffs, len3,
140 poly3inv->coeffs, len3inv,
141 ctx);
142 _TEMPLATE(T, poly_set_length) (res, len, ctx);
143 _TEMPLATE(T, poly_normalise) (res, ctx);
144
145 _TEMPLATE(T, vec_clear) (ptr2, vec_len, ctx);
146 }
147
148
149 #endif
150