This repository has been archived by the owner on Mar 27, 2020. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 1
/
pffft-double.h
184 lines (143 loc) · 7 KB
/
pffft-double.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/* Copyright (c) 2013 Julien Pommier ( [email protected] )
Based on original fortran 77 code from FFTPACKv4 from NETLIB,
authored by Dr Paul Swarztrauber of NCAR, in 1985.
As confirmed by the NCAR fftpack software curators, the following
FFTPACKv5 license applies to FFTPACKv4 sources. My changes are
released under the same terms.
FFTPACK license:
http://www.cisl.ucar.edu/css/software/fftpack5/ftpk.html
Copyright (c) 2004 the University Corporation for Atmospheric
Research ("UCAR"). All rights reserved. Developed by NCAR's
Computational and Information Systems Laboratory, UCAR,
www.cisl.ucar.edu.
Redistribution and use of the Software in source and binary forms,
with or without modification, is permitted provided that the
following conditions are met:
- Neither the names of NCAR's Computational and Information Systems
Laboratory, the University Corporation for Atmospheric Research,
nor the names of its sponsors or contributors may be used to
endorse or promote products derived from this Software without
specific prior written permission.
- Redistributions of source code must retain the above copyright
notices, this list of conditions, and the disclaimer below.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions, and the disclaimer below in the
documentation and/or other materials provided with the
distribution.
THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
SOFTWARE.
*/
/*
NOTE: This file is adapted from Julien Pommier's original PFFFT,
which works on 32 bit floating point precision using SSE instructions,
to work with 64 bit floating point precision using AVX instructions.
Author: Dario Mambro @ https://github.com/unevens/pffft
*/
/*
PFFFT : a Pretty Fast FFT.
This is basically an adaptation of the single precision fftpack
(v4) as found on netlib taking advantage of SIMD instruction found
on cpus such as intel x86 (SSE1), powerpc (Altivec), and arm (NEON).
For architectures where no SIMD instruction is available, the code
falls back to a scalar version.
Restrictions:
- 1D transforms only, with 64-bit single precision.
- supports only transforms for inputs of length N of the form
N=(2^a)*(3^b)*(5^c), a >= 5, b >=0, c >= 0 (32, 48, 64, 96, 128,
144, 160, etc are all acceptable lengths). Performance is best for
128<=N<=8192.
- all (double*) pointers in the functions below are expected to
have an "simd-compatible" alignment, that is 32 bytes on x86 and
powerpc CPUs.
You can allocate such buffers with the functions
pffft_aligned_malloc / pffft_aligned_free (or with stuff like
posix_memalign..)
*/
#ifndef PFFFT_DOUBLE_H
#define PFFFT_DOUBLE_H
#include <stddef.h> // for size_t
#ifdef __cplusplus
extern "C" {
#endif
/* opaque struct holding internal stuff (precomputed twiddle factors)
this struct can be shared by many threads as it contains only
read-only data.
*/
typedef struct PFFFTD_Setup PFFFTD_Setup;
/* direction of the transform */
typedef enum { PFFFTD_FORWARD, PFFFTD_BACKWARD } pffftd_direction_t;
/* type of transform */
typedef enum { PFFFTD_REAL, PFFFTD_COMPLEX } pffftd_transform_t;
/*
prepare for performing transforms of size N -- the returned
PFFFTD_Setup structure is read-only so it can safely be shared by
multiple concurrent threads.
*/
PFFFTD_Setup *pffftd_new_setup(int N, pffftd_transform_t transform);
void pffftd_destroy_setup(PFFFTD_Setup *);
/*
Perform a Fourier transform , The z-domain data is stored in the
most efficient order for transforming it back, or using it for
convolution. If you need to have its content sorted in the
"usual" way, that is as an array of interleaved complex numbers,
either use pffft_transform_ordered , or call pffft_zreorder after
the forward fft, and before the backward fft.
Transforms are not scaled: PFFFT_BACKWARD(PFFFT_FORWARD(x)) = N*x.
Typically you will want to scale the backward transform by 1/N.
The 'work' pointer should point to an area of N (2*N for complex
fft) doubles, properly aligned. If 'work' is NULL, then stack will
be used instead (this is probably the best strategy for small
FFTs, say for N < 16384).
input and output may alias.
*/
void pffftd_transform(PFFFTD_Setup *setup, const double *input, double *output, double *work, pffftd_direction_t direction);
/*
Similar to pffft_transform, but makes sure that the output is
ordered as expected (interleaved complex numbers). This is
similar to calling pffft_transform and then pffft_zreorder.
input and output may alias.
*/
void pffftd_transform_ordered(PFFFTD_Setup *setup, const double *input, double *output, double *work, pffftd_direction_t direction);
/*
call pffft_zreorder(.., PFFFT_FORWARD) after pffft_transform(...,
PFFFT_FORWARD) if you want to have the frequency components in
the correct "canonical" order, as interleaved complex numbers.
(for real transforms, both 0-frequency and half frequency
components, which are real, are assembled in the first entry as
F(0)+i*F(n/2+1). Note that the original fftpack did place
F(n/2+1) at the end of the arrays).
input and output should not alias.
*/
void pffftd_zreorder(PFFFTD_Setup *setup, const double *input, double *output, pffftd_direction_t direction);
/*
Perform a multiplication of the frequency components of dft_a and
dft_b and accumulate them into dft_ab. The arrays should have
been obtained with pffft_transform(.., PFFFT_FORWARD) and should
*not* have been reordered with pffft_zreorder (otherwise just
perform the operation yourself as the dft coefs are stored as
interleaved complex numbers).
the operation performed is: dft_ab += (dft_a * fdt_b)*scaling
The dft_a, dft_b and dft_ab pointers may alias.
*/
void pffftd_zconvolve_accumulate(PFFFTD_Setup *setup, const double *dft_a, const double *dft_b, double *dft_ab, double scaling);
/*
the double buffers must have the correct alignment (32-byte boundary
on intel and powerpc). This function may be used to obtain such
correctly aligned buffers.
*/
void *pffftd_aligned_malloc(size_t nb_bytes);
void pffftd_aligned_free(void *);
/* return 4 or 1 wether support AVX instructions was enabled when building pffft-double.c */
int pffftd_simd_size();
void validate_pffftd_simd();
#ifdef __cplusplus
}
#endif
#endif // PFFFT_H