furnace/extern/fftw/kernel/cpy1d.c

71 lines
1.8 KiB
C

/*
* 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
*
*/
/* out of place 1D copy routine */
#include "kernel/ifftw.h"
void X(cpy1d)(R *I, R *O, INT n0, INT is0, INT os0, INT vl)
{
INT i0, v;
A(I != O);
switch (vl) {
case 1:
if ((n0 & 1) || is0 != 1 || os0 != 1) {
for (; n0 > 0; --n0, I += is0, O += os0)
*O = *I;
break;
}
n0 /= 2; is0 = 2; os0 = 2;
/* fall through */
case 2:
if ((n0 & 1) || is0 != 2 || os0 != 2) {
for (; n0 > 0; --n0, I += is0, O += os0) {
R x0 = I[0];
R x1 = I[1];
O[0] = x0;
O[1] = x1;
}
break;
}
n0 /= 2; is0 = 4; os0 = 4;
/* fall through */
case 4:
for (; n0 > 0; --n0, I += is0, O += os0) {
R x0 = I[0];
R x1 = I[1];
R x2 = I[2];
R x3 = I[3];
O[0] = x0;
O[1] = x1;
O[2] = x2;
O[3] = x3;
}
break;
default:
for (i0 = 0; i0 < n0; ++i0)
for (v = 0; v < vl; ++v) {
R x0 = I[i0 * is0 + v];
O[i0 * os0 + v] = x0;
}
break;
}
}