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Unified Diff: Modules/_decimal/libmpdec/convolute.c

Issue 7652: Merge C version of decimal into py3k.
Patch Set: Created 7 years, 3 months ago
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Modules/_decimal/libmpdec/convolute.c Sat Mar 10 18:12:20 2012 +0100
@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2008-2010 Stefan Krah. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+
+#include "mpdecimal.h"
+#include <stdio.h>
+#include "bits.h"
+#include "constants.h"
+#include "fnt.h"
+#include "fourstep.h"
+#include "numbertheory.h"
+#include "sixstep.h"
+#include "umodarith.h"
+#include "convolute.h"
+
+
+/* Bignum: Fast convolution using the Number Theoretic Transform. Used for
+ the multiplication of very large coefficients. */
+
+
+/* Convolute the data in c1 and c2. Result is in c1. */
+int
+fnt_convolute(mpd_uint_t *c1, mpd_uint_t *c2, mpd_size_t n, int modnum)
+{
+ int (*fnt)(mpd_uint_t *, mpd_size_t, int);
+ int (*inv_fnt)(mpd_uint_t *, mpd_size_t, int);
+#ifdef PPRO
+ double dmod;
+ uint32_t dinvmod[3];
+#endif
+ mpd_uint_t n_inv, umod;
+ mpd_size_t i;
+
+
+ SETMODULUS(modnum);
+ n_inv = POWMOD(n, (umod-2));
+
+ if (ispower2(n)) {
+ if (n > SIX_STEP_THRESHOLD) {
+ fnt = six_step_fnt;
+ inv_fnt = inv_six_step_fnt;
+ }
+ else {
+ fnt = std_fnt;
+ inv_fnt = std_inv_fnt;
+ }
+ }
+ else {
+ fnt = four_step_fnt;
+ inv_fnt = inv_four_step_fnt;
+ }
+
+ if (!fnt(c1, n, modnum)) {
+ return 0;
+ }
+ if (!fnt(c2, n, modnum)) {
+ return 0;
+ }
+ for (i = 0; i < n-1; i += 2) {
+ mpd_uint_t x0 = c1[i];
+ mpd_uint_t y0 = c2[i];
+ mpd_uint_t x1 = c1[i+1];
+ mpd_uint_t y1 = c2[i+1];
+ MULMOD2(&x0, y0, &x1, y1);
+ c1[i] = x0;
+ c1[i+1] = x1;
+ }
+
+ if (!inv_fnt(c1, n, modnum)) {
+ return 0;
+ }
+ for (i = 0; i < n-3; i += 4) {
+ mpd_uint_t x0 = c1[i];
+ mpd_uint_t x1 = c1[i+1];
+ mpd_uint_t x2 = c1[i+2];
+ mpd_uint_t x3 = c1[i+3];
+ MULMOD2C(&x0, &x1, n_inv);
+ MULMOD2C(&x2, &x3, n_inv);
+ c1[i] = x0;
+ c1[i+1] = x1;
+ c1[i+2] = x2;
+ c1[i+3] = x3;
+ }
+
+ return 1;
+}
+
+/* Autoconvolute the data in c1. Result is in c1. */
+int
+fnt_autoconvolute(mpd_uint_t *c1, mpd_size_t n, int modnum)
+{
+ int (*fnt)(mpd_uint_t *, mpd_size_t, int);
+ int (*inv_fnt)(mpd_uint_t *, mpd_size_t, int);
+#ifdef PPRO
+ double dmod;
+ uint32_t dinvmod[3];
+#endif
+ mpd_uint_t n_inv, umod;
+ mpd_size_t i;
+
+
+ SETMODULUS(modnum);
+ n_inv = POWMOD(n, (umod-2));
+
+ if (ispower2(n)) {
+ if (n > SIX_STEP_THRESHOLD) {
+ fnt = six_step_fnt;
+ inv_fnt = inv_six_step_fnt;
+ }
+ else {
+ fnt = std_fnt;
+ inv_fnt = std_inv_fnt;
+ }
+ }
+ else {
+ fnt = four_step_fnt;
+ inv_fnt = inv_four_step_fnt;
+ }
+
+ if (!fnt(c1, n, modnum)) {
+ return 0;
+ }
+ for (i = 0; i < n-1; i += 2) {
+ mpd_uint_t x0 = c1[i];
+ mpd_uint_t x1 = c1[i+1];
+ MULMOD2(&x0, x0, &x1, x1);
+ c1[i] = x0;
+ c1[i+1] = x1;
+ }
+
+ if (!inv_fnt(c1, n, modnum)) {
+ return 0;
+ }
+ for (i = 0; i < n-3; i += 4) {
+ mpd_uint_t x0 = c1[i];
+ mpd_uint_t x1 = c1[i+1];
+ mpd_uint_t x2 = c1[i+2];
+ mpd_uint_t x3 = c1[i+3];
+ MULMOD2C(&x0, &x1, n_inv);
+ MULMOD2C(&x2, &x3, n_inv);
+ c1[i] = x0;
+ c1[i+1] = x1;
+ c1[i+2] = x2;
+ c1[i+3] = x3;
+ }
+
+ return 1;
+}
+
+
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