From 5a422aba704c375a307a902bafe658342e209906 Mon Sep 17 00:00:00 2001 From: scuri Date: Fri, 17 Oct 2008 06:10:15 +0000 Subject: First commit - moving from LuaForge to SourceForge --- src/fftw3/kernel/pickdim.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 src/fftw3/kernel/pickdim.c (limited to 'src/fftw3/kernel/pickdim.c') diff --git a/src/fftw3/kernel/pickdim.c b/src/fftw3/kernel/pickdim.c new file mode 100644 index 0000000..034e6db --- /dev/null +++ b/src/fftw3/kernel/pickdim.c @@ -0,0 +1,82 @@ +/* + * 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; +} -- cgit v1.2.3