Rev 107 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
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| 2 | pj | 1 | /* |
| 2 | * Copyright (c) 1997-1999 Massachusetts Institute of Technology |
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| 3 | * |
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| 4 | * This program is free software; you can redistribute it and/or modify |
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| 5 | * it under the terms of the GNU General Public License as published by |
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| 6 | * the Free Software Foundation; either version 2 of the License, or |
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| 7 | * (at your option) any later version. |
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| 8 | * |
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| 9 | * This program is distributed in the hope that it will be useful, |
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| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 12 | * GNU General Public License for more details. |
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| 13 | * |
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| 14 | * You should have received a copy of the GNU General Public License |
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| 15 | * along with this program; if not, write to the Free Software |
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| 16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 17 | * |
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| 18 | */ |
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| 19 | |||
| 20 | /* |
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| 21 | * |
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| 22 | * generic.c -- "generic" codelets. They work for all n (and they are |
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| 23 | * slow) |
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| 24 | */ |
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| 107 | pj | 25 | #include <fftw-int.h> |
| 2 | pj | 26 | #include <stdlib.h> |
| 27 | |||
| 28 | void fftw_twiddle_generic(fftw_complex *A, const fftw_complex *W, |
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| 29 | int m, int r, int n, int stride) |
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| 30 | { |
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| 31 | int i, j, k; |
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| 32 | const fftw_complex *jp; |
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| 33 | fftw_complex *kp; |
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| 34 | fftw_complex *tmp = (fftw_complex *) |
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| 35 | fftw_malloc(r * sizeof(fftw_complex)); |
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| 36 | |||
| 37 | for (i = 0; i < m; ++i) { |
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| 38 | for (k = 0, kp = tmp; k < r; ++k, kp++) { |
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| 39 | fftw_real r0, i0, rt, it, rw, iw; |
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| 40 | int l1 = i + m * k; |
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| 41 | int l0; |
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| 42 | |||
| 43 | r0 = i0 = 0.0; |
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| 44 | for (j = 0, jp = A + i * stride, l0 = 0; j < r; ++j, |
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| 45 | jp += m * stride) { |
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| 46 | rw = c_re(W[l0]); |
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| 47 | iw = c_im(W[l0]); |
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| 48 | rt = c_re(*jp); |
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| 49 | it = c_im(*jp); |
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| 50 | r0 += rt * rw - it * iw; |
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| 51 | i0 += rt * iw + it * rw; |
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| 52 | l0 += l1; |
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| 53 | if (l0 >= n) |
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| 54 | l0 -= n; |
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| 55 | } |
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| 56 | c_re(*kp) = r0; |
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| 57 | c_im(*kp) = i0; |
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| 58 | } |
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| 59 | for (k = 0, kp = A + i * stride; k < r; ++k, kp += m * stride) |
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| 60 | *kp = tmp[k]; |
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| 61 | } |
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| 62 | |||
| 63 | fftw_free(tmp); |
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| 64 | } |
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| 65 | |||
| 66 | void fftwi_twiddle_generic(fftw_complex *A, const fftw_complex *W, |
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| 67 | int m, int r, int n, int stride) |
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| 68 | { |
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| 69 | int i, j, k; |
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| 70 | const fftw_complex *jp; |
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| 71 | fftw_complex *kp; |
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| 72 | fftw_complex *tmp = (fftw_complex *) |
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| 73 | fftw_malloc(r * sizeof(fftw_complex)); |
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| 74 | |||
| 75 | for (i = 0; i < m; ++i) { |
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| 76 | for (k = 0, kp = tmp; k < r; ++k, kp++) { |
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| 77 | fftw_real r0, i0, rt, it, rw, iw; |
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| 78 | int l1 = i + m * k; |
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| 79 | int l0; |
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| 80 | |||
| 81 | r0 = i0 = 0.0; |
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| 82 | for (j = 0, jp = A + i * stride, l0 = 0; j < r; ++j, |
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| 83 | jp += m * stride) { |
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| 84 | rw = c_re(W[l0]); |
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| 85 | iw = c_im(W[l0]); |
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| 86 | rt = c_re(*jp); |
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| 87 | it = c_im(*jp); |
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| 88 | r0 += rt * rw + it * iw; |
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| 89 | i0 += it * rw - rt * iw; |
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| 90 | l0 += l1; |
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| 91 | if (l0 >= n) |
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| 92 | l0 -= n; |
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| 93 | } |
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| 94 | c_re(*kp) = r0; |
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| 95 | c_im(*kp) = i0; |
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| 96 | } |
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| 97 | for (k = 0, kp = A + i * stride; k < r; ++k, kp += m * stride) |
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| 98 | *kp = tmp[k]; |
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| 99 | } |
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| 100 | |||
| 101 | fftw_free(tmp); |
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| 102 | } |