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authorscuri <scuri>2008-10-17 06:10:15 +0000
committerscuri <scuri>2008-10-17 06:10:15 +0000
commit5a422aba704c375a307a902bafe658342e209906 (patch)
tree5005011e086bb863d8fb587ad3319bbec59b2447 /src/fftw3/kernel/pickdim.c
First commit - moving from LuaForge to SourceForge
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+/*
+ * Copyright (c) 2003 Matteo Frigo
+ * Copyright (c) 2003 Massachusetts Institute of Technology
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include "ifftw.h"
+
+/* $Id: pickdim.c,v 1.1 2008/10/17 06:11:29 scuri Exp $ */
+
+/* Given a solver which_dim, a vector sz, and whether or not the
+ transform is out-of-place, return the actual dimension index that
+ it corresponds to. The basic idea here is that we return the
+ which_dim'th valid dimension, starting from the end if
+ which_dim < 0. */
+static int really_pickdim(int which_dim, const tensor *sz, int oop, int *dp)
+{
+ int i;
+ int count_ok = 0;
+ if (which_dim > 0) {
+ for (i = 0; i < sz->rnk; ++i) {
+ if (oop || sz->dims[i].is == sz->dims[i].os)
+ if (++count_ok == which_dim) {
+ *dp = i;
+ return 1;
+ }
+ }
+ }
+ else if (which_dim < 0) {
+ for (i = sz->rnk; i > 0; --i) {
+ if (oop || sz->dims[i - 1].is == sz->dims[i - 1].os)
+ if (++count_ok == -which_dim) {
+ *dp = i - 1;
+ return 1;
+ }
+ }
+ }
+ else { /* zero: pick the middle, if valid */
+ i = sz->rnk / 2 - 1;
+ if (i < sz->rnk && (oop || sz->dims[i].is == sz->dims[i].os)) {
+ *dp = i;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/* Like really_pickdim, but only returns 1 if no previous "buddy"
+ which_dim in the buddies list would give the same dim. */
+int X(pickdim)(int which_dim, const int *buddies, int nbuddies,
+ const tensor *sz, int oop, int *dp)
+{
+ int i, d1;
+
+ if (!really_pickdim(which_dim, sz, oop, dp))
+ return 0;
+
+ /* check whether some buddy solver would produce the same dim.
+ If so, consider this solver unapplicable and let the buddy
+ take care of it. The smallest-indexed buddy is applicable. */
+ for (i = 0; i < nbuddies; ++i) {
+ if (buddies[i] == which_dim)
+ break; /* found self */
+ if (really_pickdim(buddies[i], sz, oop, &d1) && *dp == d1)
+ return 0; /* found equivalent buddy */
+ }
+ return 1;
+}