diff options
Diffstat (limited to 'src/sndobj/rfftw/twiddle.c')
| -rw-r--r-- | src/sndobj/rfftw/twiddle.c | 223 |
1 files changed, 0 insertions, 223 deletions
diff --git a/src/sndobj/rfftw/twiddle.c b/src/sndobj/rfftw/twiddle.c deleted file mode 100644 index 46938f6..0000000 --- a/src/sndobj/rfftw/twiddle.c +++ /dev/null @@ -1,223 +0,0 @@ -/*
- * Copyright (c) 1997-1999 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- */
-
-/*
- * twiddle.c -- compute twiddle factors
- * These are the twiddle factors for *direct* fft. Flip sign to get
- * the inverse
- */
-
-/* $Id: twiddle.c,v 1.1.1.1 2006/05/12 15:14:43 veplaini Exp $ */
-#ifdef FFTW_USING_CILK
-#include <cilk.h>
-#include <cilk-compat.h>
-#endif
-
-#include <fftw-int.h>
-#include <math.h>
-#include <stdlib.h>
-#include <limits.h>
-
-#ifndef TRUE
-#define TRUE (1 == 1)
-#endif
-
-#ifndef FALSE
-#define FALSE (1 == 0)
-#endif
-
-#ifdef USE_FFTW_SAFE_MULMOD
-/* compute (x * y) mod p, but watch out for integer overflows; we must
- have x, y >= 0, p > 0. This routine is slow. */
-int fftw_safe_mulmod(int x, int y, int p)
-{
- if (y == 0 || x <= INT_MAX / y)
- return((x * y) % p);
- else {
- int y2 = y/2;
- return((fftw_safe_mulmod(x, y2, p) +
- fftw_safe_mulmod(x, y - y2, p)) % p);
- }
-}
-#endif /* USE_FFTW_SAFE_MULMOD */
-
-static fftw_complex *fftw_compute_rader_twiddle(int n, int r, int g)
-{
- FFTW_TRIG_REAL twoPiOverN;
- int m = n / r;
- int i, j, gpower;
- fftw_complex *W;
-
- twoPiOverN = FFTW_K2PI / (FFTW_TRIG_REAL) n;
- W = (fftw_complex *) fftw_malloc((r - 1) * m * sizeof(fftw_complex));
- for (i = 0; i < m; ++i)
- for (gpower = 1, j = 0; j < r - 1; ++j,
- gpower = MULMOD(gpower, g, r)) {
- int k = i * (r - 1) + j;
- FFTW_TRIG_REAL
- ij = (FFTW_TRIG_REAL) (i * gpower);
- c_re(W[k]) = FFTW_TRIG_COS(twoPiOverN * ij);
- c_im(W[k]) = FFTW_FORWARD * FFTW_TRIG_SIN(twoPiOverN * ij);
- }
-
- return W;
-}
-
-/*
- * compute the W coefficients (that is, powers of the root of 1)
- * and store them into an array.
- */
-static fftw_complex *fftw_compute_twiddle(int n, const fftw_codelet_desc *d)
-{
- FFTW_TRIG_REAL twoPiOverN;
- int i, j;
- fftw_complex *W;
-
- twoPiOverN = FFTW_K2PI / (FFTW_TRIG_REAL) n;
-
- if (!d) {
- /* generic codelet, needs all twiddles in order */
- W = (fftw_complex *) fftw_malloc(n * sizeof(fftw_complex));
- for (i = 0; i < n; ++i) {
- c_re(W[i]) = FFTW_TRIG_COS(twoPiOverN * (FFTW_TRIG_REAL) i);
- c_im(W[i]) = FFTW_FORWARD * FFTW_TRIG_SIN(twoPiOverN * (FFTW_TRIG_REAL) i);
- }
- } else if (d->type == FFTW_RADER)
- W = fftw_compute_rader_twiddle(n, d->size, d->signature);
- else {
- int r = d->size;
- int m = n / r, m_alloc;
- int r1 = d->ntwiddle;
- int istart;
-
- if (d->type == FFTW_TWIDDLE) {
- istart = 0;
- m_alloc = m;
- } else if (d->type == FFTW_HC2HC) {
- /*
- * This is tricky, do not change lightly.
- */
- m = (m + 1) / 2;
- m_alloc = m - 1;
- istart = 1;
- } else {
- fftw_die("compute_twiddle: invalid argument\n");
- /* paranoia for gcc */
- m_alloc = 0;
- istart = 0;
- }
-
- W = (fftw_complex *) fftw_malloc(r1 * m_alloc * sizeof(fftw_complex));
- for (i = istart; i < m; ++i)
- for (j = 0; j < r1; ++j) {
- int k = (i - istart) * r1 + j;
- FFTW_TRIG_REAL
- ij = (FFTW_TRIG_REAL) (i * d->twiddle_order[j]);
- c_re(W[k]) = FFTW_TRIG_COS(twoPiOverN * ij);
- c_im(W[k]) = FFTW_FORWARD * FFTW_TRIG_SIN(twoPiOverN * ij);
- }
- }
-
- return W;
-}
-
-/*
- * these routines implement a simple reference-count-based
- * management of twiddle structures
- */
-static fftw_twiddle *twlist = (fftw_twiddle *) 0;
-int fftw_twiddle_size = 0; /* total allocated size, for debugging */
-
-/* true if the two codelets can share the same twiddle factors */
-static int compatible(const fftw_codelet_desc *d1, const fftw_codelet_desc *d2)
-{
- int i;
-
- /* true if they are the same codelet */
- if (d1 == d2)
- return TRUE;
-
- /* false if one is null and the other is not */
- if (!d1 || !d2)
- return FALSE;
-
- /* false if size is different */
- if (d1->size != d2->size)
- return FALSE;
-
- /* false if different types (FFTW_TWIDDLE/FFTW_HC2HC/FFTW_RADER) */
- if (d1->type != d2->type)
- return FALSE;
-
- /* false if they need different # of twiddles */
- if (d1->ntwiddle != d2->ntwiddle)
- return FALSE;
-
- /* false if the twiddle orders are different */
- for (i = 0; i < d1->ntwiddle; ++i)
- if (d1->twiddle_order[i] != d2->twiddle_order[i])
- return FALSE;
-
- return TRUE;
-}
-
-fftw_twiddle *fftw_create_twiddle(int n, const fftw_codelet_desc *d)
-{
- fftw_twiddle *tw;
-
- /* lookup this n in the twiddle list */
- for (tw = twlist; tw; tw = tw->next)
- if (n == tw->n && compatible(d, tw->cdesc)) {
- ++tw->refcnt;
- return tw;
- }
- /* not found --- allocate a new struct twiddle */
- tw = (fftw_twiddle *) fftw_malloc(sizeof(fftw_twiddle));
- fftw_twiddle_size += n;
-
- tw->n = n;
- tw->cdesc = d;
- tw->twarray = fftw_compute_twiddle(n, d);
- tw->refcnt = 1;
-
- /* enqueue the new struct */
- tw->next = twlist;
- twlist = tw;
-
- return tw;
-}
-
-void fftw_destroy_twiddle(fftw_twiddle * tw)
-{
- fftw_twiddle **p;
- --tw->refcnt;
-
- if (tw->refcnt == 0) {
- /* remove from the list of known twiddle factors */
- for (p = &twlist; p; p = &((*p)->next))
- if (*p == tw) {
- *p = tw->next;
- fftw_twiddle_size -= tw->n;
- fftw_free(tw->twarray);
- fftw_free(tw);
- return;
- }
- fftw_die("BUG in fftw_destroy_twiddle\n");
- }
-}
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