furnace/extern/fftw/dft/zero.c

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/*
* Copyright (c) 2003, 2007-14 Matteo Frigo
* Copyright (c) 2003, 2007-14 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include "dft/dft.h"
/* fill a complex array with zeros. */
static void recur(const iodim *dims, int rnk, R *ri, R *ii)
{
if (rnk == RNK_MINFTY)
return;
else if (rnk == 0)
ri[0] = ii[0] = K(0.0);
else if (rnk > 0) {
INT i, n = dims[0].n;
INT is = dims[0].is;
if (rnk == 1) {
/* this case is redundant but faster */
for (i = 0; i < n; ++i)
ri[i * is] = ii[i * is] = K(0.0);
} else {
for (i = 0; i < n; ++i)
recur(dims + 1, rnk - 1, ri + i * is, ii + i * is);
}
}
}
void X(dft_zerotens)(tensor *sz, R *ri, R *ii)
{
recur(sz->dims, sz->rnk, ri, ii);
}