annotate src/fftw-3.3.8/kernel/buffered.c @ 84:08ae793730bd

Add null config files
author Chris Cannam
date Mon, 02 Mar 2020 14:03:47 +0000
parents d0c2a83c1364
children
rev   line source
Chris@82 1 /*
Chris@82 2 * Copyright (c) 2003, 2007-14 Matteo Frigo
Chris@82 3 * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
Chris@82 4 *
Chris@82 5 * This program is free software; you can redistribute it and/or modify
Chris@82 6 * it under the terms of the GNU General Public License as published by
Chris@82 7 * the Free Software Foundation; either version 2 of the License, or
Chris@82 8 * (at your option) any later version.
Chris@82 9 *
Chris@82 10 * This program is distributed in the hope that it will be useful,
Chris@82 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@82 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
Chris@82 13 * GNU General Public License for more details.
Chris@82 14 *
Chris@82 15 * You should have received a copy of the GNU General Public License
Chris@82 16 * along with this program; if not, write to the Free Software
Chris@82 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
Chris@82 18 *
Chris@82 19 */
Chris@82 20
Chris@82 21 /* routines shared by the various buffered solvers */
Chris@82 22
Chris@82 23 #include "kernel/ifftw.h"
Chris@82 24
Chris@82 25 #define DEFAULT_MAXNBUF ((INT)256)
Chris@82 26
Chris@82 27 /* approx. 512KB of buffers for complex data */
Chris@82 28 #define MAXBUFSZ (256 * 1024 / (INT)(sizeof(R)))
Chris@82 29
Chris@82 30 INT X(nbuf)(INT n, INT vl, INT maxnbuf)
Chris@82 31 {
Chris@82 32 INT i, nbuf, lb;
Chris@82 33
Chris@82 34 if (!maxnbuf)
Chris@82 35 maxnbuf = DEFAULT_MAXNBUF;
Chris@82 36
Chris@82 37 nbuf = X(imin)(maxnbuf,
Chris@82 38 X(imin)(vl, X(imax)((INT)1, MAXBUFSZ / n)));
Chris@82 39
Chris@82 40 /*
Chris@82 41 * Look for a buffer number (not too small) that divides the
Chris@82 42 * vector length, in order that we only need one child plan:
Chris@82 43 */
Chris@82 44 lb = X(imax)(1, nbuf / 4);
Chris@82 45 for (i = nbuf; i >= lb; --i)
Chris@82 46 if (vl % i == 0)
Chris@82 47 return i;
Chris@82 48
Chris@82 49 /* whatever... */
Chris@82 50 return nbuf;
Chris@82 51 }
Chris@82 52
Chris@82 53 #define SKEW 6 /* need to be even for SIMD */
Chris@82 54 #define SKEWMOD 8
Chris@82 55
Chris@82 56 INT X(bufdist)(INT n, INT vl)
Chris@82 57 {
Chris@82 58 if (vl == 1)
Chris@82 59 return n;
Chris@82 60 else
Chris@82 61 /* return smallest X such that X >= N and X == SKEW (mod SKEWMOD) */
Chris@82 62 return n + X(modulo)(SKEW - n, SKEWMOD);
Chris@82 63 }
Chris@82 64
Chris@82 65 int X(toobig)(INT n)
Chris@82 66 {
Chris@82 67 return n > MAXBUFSZ;
Chris@82 68 }
Chris@82 69
Chris@82 70 /* TRUE if there exists i < which such that maxnbuf[i] and
Chris@82 71 maxnbuf[which] yield the same value, in which case we canonicalize
Chris@82 72 on the minimum value */
Chris@82 73 int X(nbuf_redundant)(INT n, INT vl, size_t which,
Chris@82 74 const INT *maxnbuf, size_t nmaxnbuf)
Chris@82 75 {
Chris@82 76 size_t i;
Chris@82 77 (void)nmaxnbuf; /* UNUSED */
Chris@82 78 for (i = 0; i < which; ++i)
Chris@82 79 if (X(nbuf)(n, vl, maxnbuf[i]) == X(nbuf)(n, vl, maxnbuf[which]))
Chris@82 80 return 1;
Chris@82 81 return 0;
Chris@82 82 }