annotate src/fftw-3.3.8/kernel/buffered.c @ 83:ae30d91d2ffe

Replace these with versions built using an older toolset (so as to avoid ABI compatibilities when linking on Ubuntu 14.04 for packaging purposes)
author Chris Cannam
date Fri, 07 Feb 2020 11:51:13 +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 }