Project Ne10
An Open Optimized Software Library Project for the ARM Architecture
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NE10_fft_common_varibles.h
1/*
2 * Copyright 2014-15 ARM Limited and Contributors.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of ARM Limited nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY ARM LIMITED AND CONTRIBUTORS "AS IS" AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL ARM LIMITED BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28/*
29 * NE10 Library : dsp/NE10_fft_common_varibles.h
30 */
31
32#include "NE10_types.h"
33
34#ifndef NE10_FFT_COMMON_VARIBLES_H
35#define NE10_FFT_COMMON_VARIBLES_H
36
38// common varibles
40
41/* Twiddles used in Radix-8 FFT */
42static const ne10_float32_t TW_81_F32 = 0.70710678; // sqrt (2) / 2
43static const ne10_float32_t TW_81N_F32 = -0.70710678; // - TW_81_F32
44
45/* Twiddles used in Radix-5 FFT */
46static const ne10_fft_cpx_float32_t TW_5A_F32 =
47 {
48 0.309016994374947, // cos (2 * pi / 5)
49 -0.951056516295154 // - sin (2 * pi / 5)
50 };
51static const ne10_fft_cpx_int32_t TW_5A_S32 =
52 {
53 663608942, // round (TW_5A_F32.r * 2^31)
54 -2042378317 // round (TW_5A_F32.i * 2^31)
55 };
56
57static const ne10_fft_cpx_float32_t TW_5B_F32 =
58 {
59 -0.809016994374947, // cos (4 * pi / 5)
60 -0.587785252292473 // - sin (4 * pi / 5)
61 };
62static const ne10_fft_cpx_int32_t TW_5B_S32 =
63 {
64 -1737350766, // round (TW_5B_F32.r * 2^31)
65 -1262259218 // round (TW_5B_F32.i * 2^31)
66 };
67
68/* Twiddles used in Radix-3 FFT */
69static const ne10_float32_t TW_3I_F32 = 0.866025403784439; // sqrt (3) / 2
70static const ne10_float32_t TW_3IN_F32 = - 0.866025403784439; // - TW_3IN_F32
71static const ne10_int32_t TW_3I_S32 = 1859775393; // round (TW_3I_F32 * 2^31)
72static const ne10_int32_t TW_3IN_S32 = -1859775393; // round (TW_3IN_F32 * 2^31)
73
74#endif // NE10_FFT_COMMON_VARIBLES_H
structure for the 32 bits fixed point FFT function.
Definition NE10_types.h:329