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Side by Side Diff: Modules/_decimal/libmpdec/convolute.c

Issue 7652: Merge C version of decimal into py3k.
Patch Set: Created 7 years, 6 months ago
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1 /*
2 * Copyright (c) 2008-2010 Stefan Krah. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28
29 #include "mpdecimal.h"
30 #include <stdio.h>
31 #include "bits.h"
32 #include "constants.h"
33 #include "fnt.h"
34 #include "fourstep.h"
35 #include "numbertheory.h"
36 #include "sixstep.h"
37 #include "umodarith.h"
38 #include "convolute.h"
39
40
41 /* Bignum: Fast convolution using the Number Theoretic Transform. Used for
42 the multiplication of very large coefficients. */
43
44
45 /* Convolute the data in c1 and c2. Result is in c1. */
46 int
47 fnt_convolute(mpd_uint_t *c1, mpd_uint_t *c2, mpd_size_t n, int modnum)
48 {
49 int (*fnt)(mpd_uint_t *, mpd_size_t, int);
50 int (*inv_fnt)(mpd_uint_t *, mpd_size_t, int);
51 #ifdef PPRO
52 double dmod;
53 uint32_t dinvmod[3];
54 #endif
55 mpd_uint_t n_inv, umod;
56 mpd_size_t i;
57
58
59 SETMODULUS(modnum);
60 n_inv = POWMOD(n, (umod-2));
61
62 if (ispower2(n)) {
63 if (n > SIX_STEP_THRESHOLD) {
64 fnt = six_step_fnt;
65 inv_fnt = inv_six_step_fnt;
66 }
67 else {
68 fnt = std_fnt;
69 inv_fnt = std_inv_fnt;
70 }
71 }
72 else {
73 fnt = four_step_fnt;
74 inv_fnt = inv_four_step_fnt;
75 }
76
77 if (!fnt(c1, n, modnum)) {
78 return 0;
79 }
80 if (!fnt(c2, n, modnum)) {
81 return 0;
82 }
83 for (i = 0; i < n-1; i += 2) {
84 mpd_uint_t x0 = c1[i];
85 mpd_uint_t y0 = c2[i];
86 mpd_uint_t x1 = c1[i+1];
87 mpd_uint_t y1 = c2[i+1];
88 MULMOD2(&x0, y0, &x1, y1);
89 c1[i] = x0;
90 c1[i+1] = x1;
91 }
92
93 if (!inv_fnt(c1, n, modnum)) {
94 return 0;
95 }
96 for (i = 0; i < n-3; i += 4) {
97 mpd_uint_t x0 = c1[i];
98 mpd_uint_t x1 = c1[i+1];
99 mpd_uint_t x2 = c1[i+2];
100 mpd_uint_t x3 = c1[i+3];
101 MULMOD2C(&x0, &x1, n_inv);
102 MULMOD2C(&x2, &x3, n_inv);
103 c1[i] = x0;
104 c1[i+1] = x1;
105 c1[i+2] = x2;
106 c1[i+3] = x3;
107 }
108
109 return 1;
110 }
111
112 /* Autoconvolute the data in c1. Result is in c1. */
113 int
114 fnt_autoconvolute(mpd_uint_t *c1, mpd_size_t n, int modnum)
115 {
116 int (*fnt)(mpd_uint_t *, mpd_size_t, int);
117 int (*inv_fnt)(mpd_uint_t *, mpd_size_t, int);
118 #ifdef PPRO
119 double dmod;
120 uint32_t dinvmod[3];
121 #endif
122 mpd_uint_t n_inv, umod;
123 mpd_size_t i;
124
125
126 SETMODULUS(modnum);
127 n_inv = POWMOD(n, (umod-2));
128
129 if (ispower2(n)) {
130 if (n > SIX_STEP_THRESHOLD) {
131 fnt = six_step_fnt;
132 inv_fnt = inv_six_step_fnt;
133 }
134 else {
135 fnt = std_fnt;
136 inv_fnt = std_inv_fnt;
137 }
138 }
139 else {
140 fnt = four_step_fnt;
141 inv_fnt = inv_four_step_fnt;
142 }
143
144 if (!fnt(c1, n, modnum)) {
145 return 0;
146 }
147 for (i = 0; i < n-1; i += 2) {
148 mpd_uint_t x0 = c1[i];
149 mpd_uint_t x1 = c1[i+1];
150 MULMOD2(&x0, x0, &x1, x1);
151 c1[i] = x0;
152 c1[i+1] = x1;
153 }
154
155 if (!inv_fnt(c1, n, modnum)) {
156 return 0;
157 }
158 for (i = 0; i < n-3; i += 4) {
159 mpd_uint_t x0 = c1[i];
160 mpd_uint_t x1 = c1[i+1];
161 mpd_uint_t x2 = c1[i+2];
162 mpd_uint_t x3 = c1[i+3];
163 MULMOD2C(&x0, &x1, n_inv);
164 MULMOD2C(&x2, &x3, n_inv);
165 c1[i] = x0;
166 c1[i+1] = x1;
167 c1[i+2] = x2;
168 c1[i+3] = x3;
169 }
170
171 return 1;
172 }
173
174
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