Rietveld Code Review Tool
Help | Bug tracker | Discussion group | Source code | Sign in
(117064)

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

Issue 7652: Merge C version of decimal into py3k.
Patch Set: Created 7 years, 8 months ago
Use n/p to move between diff chunks; N/P to move between comments. Please Sign in to add in-line comments.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « Modules/_decimal/libmpdec/README.txt ('k') | Modules/_decimal/libmpdec/sixstep.h » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Modules/_decimal/libmpdec/sixstep.c Sat Mar 10 18:12:20 2012 +0100
@@ -0,0 +1,212 @@
+/*
+ * 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 <stdlib.h>
+#include <assert.h>
+#include "bits.h"
+#include "difradix2.h"
+#include "numbertheory.h"
+#include "transpose.h"
+#include "umodarith.h"
+#include "sixstep.h"
+
+
+/* Bignum: Cache efficient Matrix Fourier Transform for arrays of the
+ form 2**n (See literature/six-step.txt). */
+
+
+/* forward transform with sign = -1 */
+int
+six_step_fnt(mpd_uint_t *a, mpd_size_t n, int modnum)
+{
+ struct fnt_params *tparams;
+ mpd_size_t log2n, C, R;
+ mpd_uint_t kernel;
+ mpd_uint_t umod;
+#ifdef PPRO
+ double dmod;
+ uint32_t dinvmod[3];
+#endif
+ mpd_uint_t *x, w0, w1, wstep;
+ mpd_size_t i, k;
+
+
+ assert(ispower2(n));
+ assert(n >= 16);
+ assert(n <= MPD_MAXTRANSFORM_2N);
+
+ log2n = mpd_bsr(n);
+ C = ((mpd_size_t)1) << (log2n / 2); /* number of columns */
+ R = ((mpd_size_t)1) << (log2n - (log2n / 2)); /* number of rows */
+
+
+ /* Transpose the matrix. */
+ if (!transpose_pow2(a, R, C)) {
+ return 0;
+ }
+
+ /* Length R transform on the rows. */
+ if ((tparams = _mpd_init_fnt_params(R, -1, modnum)) == NULL) {
+ return 0;
+ }
+ for (x = a; x < a+n; x += R) {
+ fnt_dif2(x, R, tparams);
+ }
+
+ /* Transpose the matrix. */
+ if (!transpose_pow2(a, C, R)) {
+ mpd_free(tparams);
+ return 0;
+ }
+
+ /* Multiply each matrix element (addressed by i*C+k) by r**(i*k). */
+ SETMODULUS(modnum);
+ kernel = _mpd_getkernel(n, -1, modnum);
+ for (i = 1; i < R; i++) {
+ w0 = 1; /* r**(i*0): initial value for k=0 */
+ w1 = POWMOD(kernel, i); /* r**(i*1): initial value for k=1 */
+ wstep = MULMOD(w1, w1); /* r**(2*i) */
+ for (k = 0; k < C; k += 2) {
+ mpd_uint_t x0 = a[i*C+k];
+ mpd_uint_t x1 = a[i*C+k+1];
+ MULMOD2(&x0, w0, &x1, w1);
+ MULMOD2C(&w0, &w1, wstep); /* r**(i*(k+2)) = r**(i*k) * r**(2*i) */
+ a[i*C+k] = x0;
+ a[i*C+k+1] = x1;
+ }
+ }
+
+ /* Length C transform on the rows. */
+ if (C != R) {
+ mpd_free(tparams);
+ if ((tparams = _mpd_init_fnt_params(C, -1, modnum)) == NULL) {
+ return 0;
+ }
+ }
+ for (x = a; x < a+n; x += C) {
+ fnt_dif2(x, C, tparams);
+ }
+ mpd_free(tparams);
+
+#if 0 /* An unordered transform is sufficient for convolution. */
+ /* Transpose the matrix. */
+ if (!transpose_pow2(a, R, C)) {
+ return 0;
+ }
+#endif
+
+ return 1;
+}
+
+
+/* reverse transform, sign = 1 */
+int
+inv_six_step_fnt(mpd_uint_t *a, mpd_size_t n, int modnum)
+{
+ struct fnt_params *tparams;
+ mpd_size_t log2n, C, R;
+ mpd_uint_t kernel;
+ mpd_uint_t umod;
+#ifdef PPRO
+ double dmod;
+ uint32_t dinvmod[3];
+#endif
+ mpd_uint_t *x, w0, w1, wstep;
+ mpd_size_t i, k;
+
+
+ assert(ispower2(n));
+ assert(n >= 16);
+ assert(n <= MPD_MAXTRANSFORM_2N);
+
+ log2n = mpd_bsr(n);
+ C = ((mpd_size_t)1) << (log2n / 2); /* number of columns */
+ R = ((mpd_size_t)1) << (log2n - (log2n / 2)); /* number of rows */
+
+
+#if 0 /* An unordered transform is sufficient for convolution. */
+ /* Transpose the matrix, producing an R*C matrix. */
+ if (!transpose_pow2(a, C, R)) {
+ return 0;
+ }
+#endif
+
+ /* Length C transform on the rows. */
+ if ((tparams = _mpd_init_fnt_params(C, 1, modnum)) == NULL) {
+ return 0;
+ }
+ for (x = a; x < a+n; x += C) {
+ fnt_dif2(x, C, tparams);
+ }
+
+ /* Multiply each matrix element (addressed by i*C+k) by r**(i*k). */
+ SETMODULUS(modnum);
+ kernel = _mpd_getkernel(n, 1, modnum);
+ for (i = 1; i < R; i++) {
+ w0 = 1;
+ w1 = POWMOD(kernel, i);
+ wstep = MULMOD(w1, w1);
+ for (k = 0; k < C; k += 2) {
+ mpd_uint_t x0 = a[i*C+k];
+ mpd_uint_t x1 = a[i*C+k+1];
+ MULMOD2(&x0, w0, &x1, w1);
+ MULMOD2C(&w0, &w1, wstep);
+ a[i*C+k] = x0;
+ a[i*C+k+1] = x1;
+ }
+ }
+
+ /* Transpose the matrix. */
+ if (!transpose_pow2(a, R, C)) {
+ mpd_free(tparams);
+ return 0;
+ }
+
+ /* Length R transform on the rows. */
+ if (R != C) {
+ mpd_free(tparams);
+ if ((tparams = _mpd_init_fnt_params(R, 1, modnum)) == NULL) {
+ return 0;
+ }
+ }
+ for (x = a; x < a+n; x += R) {
+ fnt_dif2(x, R, tparams);
+ }
+ mpd_free(tparams);
+
+ /* Transpose the matrix. */
+ if (!transpose_pow2(a, C, R)) {
+ return 0;
+ }
+
+ return 1;
+}
+
+
« no previous file with comments | « Modules/_decimal/libmpdec/README.txt ('k') | Modules/_decimal/libmpdec/sixstep.h » ('j') | no next file with comments »

RSS Feeds Recent Issues | This issue
This is Rietveld 894c83f36cb7+