cannam@95: /* cannam@95: * Copyright (c) 2003, 2007-11 Matteo Frigo cannam@95: * Copyright (c) 2003, 2007-11 Massachusetts Institute of Technology cannam@95: * cannam@95: * This program is free software; you can redistribute it and/or modify cannam@95: * it under the terms of the GNU General Public License as published by cannam@95: * the Free Software Foundation; either version 2 of the License, or cannam@95: * (at your option) any later version. cannam@95: * cannam@95: * This program is distributed in the hope that it will be useful, cannam@95: * but WITHOUT ANY WARRANTY; without even the implied warranty of cannam@95: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the cannam@95: * GNU General Public License for more details. cannam@95: * cannam@95: * You should have received a copy of the GNU General Public License cannam@95: * along with this program; if not, write to the Free Software cannam@95: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA cannam@95: * cannam@95: */ cannam@95: cannam@95: #include "ifftw.h" cannam@95: cannam@95: cannam@95: /* Given a solver which_dim, a vector sz, and whether or not the cannam@95: transform is out-of-place, return the actual dimension index that cannam@95: it corresponds to. The basic idea here is that we return the cannam@95: which_dim'th valid dimension, starting from the end if cannam@95: which_dim < 0. */ cannam@95: static int really_pickdim(int which_dim, const tensor *sz, int oop, int *dp) cannam@95: { cannam@95: int i; cannam@95: int count_ok = 0; cannam@95: if (which_dim > 0) { cannam@95: for (i = 0; i < sz->rnk; ++i) { cannam@95: if (oop || sz->dims[i].is == sz->dims[i].os) cannam@95: if (++count_ok == which_dim) { cannam@95: *dp = i; cannam@95: return 1; cannam@95: } cannam@95: } cannam@95: } cannam@95: else if (which_dim < 0) { cannam@95: for (i = sz->rnk - 1; i >= 0; --i) { cannam@95: if (oop || sz->dims[i].is == sz->dims[i].os) cannam@95: if (++count_ok == -which_dim) { cannam@95: *dp = i; cannam@95: return 1; cannam@95: } cannam@95: } cannam@95: } cannam@95: else { /* zero: pick the middle, if valid */ cannam@95: i = (sz->rnk - 1) / 2; cannam@95: if (i >= 0 && (oop || sz->dims[i].is == sz->dims[i].os)) { cannam@95: *dp = i; cannam@95: return 1; cannam@95: } cannam@95: } cannam@95: return 0; cannam@95: } cannam@95: cannam@95: /* Like really_pickdim, but only returns 1 if no previous "buddy" cannam@95: which_dim in the buddies list would give the same dim. */ cannam@95: int X(pickdim)(int which_dim, const int *buddies, int nbuddies, cannam@95: const tensor *sz, int oop, int *dp) cannam@95: { cannam@95: int i, d1; cannam@95: cannam@95: if (!really_pickdim(which_dim, sz, oop, dp)) cannam@95: return 0; cannam@95: cannam@95: /* check whether some buddy solver would produce the same dim. cannam@95: If so, consider this solver unapplicable and let the buddy cannam@95: take care of it. The smallest-indexed buddy is applicable. */ cannam@95: for (i = 0; i < nbuddies; ++i) { cannam@95: if (buddies[i] == which_dim) cannam@95: break; /* found self */ cannam@95: if (really_pickdim(buddies[i], sz, oop, &d1) && *dp == d1) cannam@95: return 0; /* found equivalent buddy */ cannam@95: } cannam@95: return 1; cannam@95: }