Robert Lopez / CMSIS5

Aded CMSIS5 DSP and NN folder. Needs some work

DSP/source/TransformFunctions/arm_bitreversal.c@0:eedb7d567a5d, 2018-04-12 (annotated)

Committer:
robert_lp
Date:
Thu Apr 12 01:31:58 2018 +0000
Revision:
0:eedb7d567a5d
CMSIS5 Library

Who changed what in which revision?

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robert_lp 0:eedb7d567a5d 1 /* ----------------------------------------------------------------------
robert_lp 0:eedb7d567a5d 2 * Project: CMSIS DSP Library
robert_lp 0:eedb7d567a5d 3 * Title: arm_bitreversal.c
robert_lp 0:eedb7d567a5d 4 * Description: Bitreversal functions
robert_lp 0:eedb7d567a5d 5 *
robert_lp 0:eedb7d567a5d 6 * $Date: 27. January 2017
robert_lp 0:eedb7d567a5d 7 * $Revision: V.1.5.1
robert_lp 0:eedb7d567a5d 8 *
robert_lp 0:eedb7d567a5d 9 * Target Processor: Cortex-M cores
robert_lp 0:eedb7d567a5d 10 * -------------------------------------------------------------------- */
robert_lp 0:eedb7d567a5d 11 /*
robert_lp 0:eedb7d567a5d 12 * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
robert_lp 0:eedb7d567a5d 13 *
robert_lp 0:eedb7d567a5d 14 * SPDX-License-Identifier: Apache-2.0
robert_lp 0:eedb7d567a5d 15 *
robert_lp 0:eedb7d567a5d 16 * Licensed under the Apache License, Version 2.0 (the License); you may
robert_lp 0:eedb7d567a5d 17 * not use this file except in compliance with the License.
robert_lp 0:eedb7d567a5d 18 * You may obtain a copy of the License at
robert_lp 0:eedb7d567a5d 19 *
robert_lp 0:eedb7d567a5d 20 * www.apache.org/licenses/LICENSE-2.0
robert_lp 0:eedb7d567a5d 21 *
robert_lp 0:eedb7d567a5d 22 * Unless required by applicable law or agreed to in writing, software
robert_lp 0:eedb7d567a5d 23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
robert_lp 0:eedb7d567a5d 24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
robert_lp 0:eedb7d567a5d 25 * See the License for the specific language governing permissions and
robert_lp 0:eedb7d567a5d 26 * limitations under the License.
robert_lp 0:eedb7d567a5d 27 */
robert_lp 0:eedb7d567a5d 28
robert_lp 0:eedb7d567a5d 29 #include "arm_math.h"
robert_lp 0:eedb7d567a5d 30 #include "arm_common_tables.h"
robert_lp 0:eedb7d567a5d 31
robert_lp 0:eedb7d567a5d 32 /*
robert_lp 0:eedb7d567a5d 33 * @brief In-place bit reversal function.
robert_lp 0:eedb7d567a5d 34 * @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
robert_lp 0:eedb7d567a5d 35 * @param[in] fftSize length of the FFT.
robert_lp 0:eedb7d567a5d 36 * @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table.
robert_lp 0:eedb7d567a5d 37 * @param[in] *pBitRevTab points to the bit reversal table.
robert_lp 0:eedb7d567a5d 38 * @return none.
robert_lp 0:eedb7d567a5d 39 */
robert_lp 0:eedb7d567a5d 40
robert_lp 0:eedb7d567a5d 41 void arm_bitreversal_f32(
robert_lp 0:eedb7d567a5d 42 float32_t * pSrc,
robert_lp 0:eedb7d567a5d 43 uint16_t fftSize,
robert_lp 0:eedb7d567a5d 44 uint16_t bitRevFactor,
robert_lp 0:eedb7d567a5d 45 uint16_t * pBitRevTab)
robert_lp 0:eedb7d567a5d 46 {
robert_lp 0:eedb7d567a5d 47 uint16_t fftLenBy2, fftLenBy2p1;
robert_lp 0:eedb7d567a5d 48 uint16_t i, j;
robert_lp 0:eedb7d567a5d 49 float32_t in;
robert_lp 0:eedb7d567a5d 50
robert_lp 0:eedb7d567a5d 51 /* Initializations */
robert_lp 0:eedb7d567a5d 52 j = 0U;
robert_lp 0:eedb7d567a5d 53 fftLenBy2 = fftSize >> 1U;
robert_lp 0:eedb7d567a5d 54 fftLenBy2p1 = (fftSize >> 1U) + 1U;
robert_lp 0:eedb7d567a5d 55
robert_lp 0:eedb7d567a5d 56 /* Bit Reversal Implementation */
robert_lp 0:eedb7d567a5d 57 for (i = 0U; i <= (fftLenBy2 - 2U); i += 2U)
robert_lp 0:eedb7d567a5d 58 {
robert_lp 0:eedb7d567a5d 59 if (i < j)
robert_lp 0:eedb7d567a5d 60 {
robert_lp 0:eedb7d567a5d 61 /* pSrc[i] <-> pSrc[j]; */
robert_lp 0:eedb7d567a5d 62 in = pSrc[2U * i];
robert_lp 0:eedb7d567a5d 63 pSrc[2U * i] = pSrc[2U * j];
robert_lp 0:eedb7d567a5d 64 pSrc[2U * j] = in;
robert_lp 0:eedb7d567a5d 65
robert_lp 0:eedb7d567a5d 66 /* pSrc[i+1U] <-> pSrc[j+1U] */
robert_lp 0:eedb7d567a5d 67 in = pSrc[(2U * i) + 1U];
robert_lp 0:eedb7d567a5d 68 pSrc[(2U * i) + 1U] = pSrc[(2U * j) + 1U];
robert_lp 0:eedb7d567a5d 69 pSrc[(2U * j) + 1U] = in;
robert_lp 0:eedb7d567a5d 70
robert_lp 0:eedb7d567a5d 71 /* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
robert_lp 0:eedb7d567a5d 72 in = pSrc[2U * (i + fftLenBy2p1)];
robert_lp 0:eedb7d567a5d 73 pSrc[2U * (i + fftLenBy2p1)] = pSrc[2U * (j + fftLenBy2p1)];
robert_lp 0:eedb7d567a5d 74 pSrc[2U * (j + fftLenBy2p1)] = in;
robert_lp 0:eedb7d567a5d 75
robert_lp 0:eedb7d567a5d 76 /* pSrc[i+fftLenBy2p1+1U] <-> pSrc[j+fftLenBy2p1+1U] */
robert_lp 0:eedb7d567a5d 77 in = pSrc[(2U * (i + fftLenBy2p1)) + 1U];
robert_lp 0:eedb7d567a5d 78 pSrc[(2U * (i + fftLenBy2p1)) + 1U] =
robert_lp 0:eedb7d567a5d 79 pSrc[(2U * (j + fftLenBy2p1)) + 1U];
robert_lp 0:eedb7d567a5d 80 pSrc[(2U * (j + fftLenBy2p1)) + 1U] = in;
robert_lp 0:eedb7d567a5d 81
robert_lp 0:eedb7d567a5d 82 }
robert_lp 0:eedb7d567a5d 83
robert_lp 0:eedb7d567a5d 84 /* pSrc[i+1U] <-> pSrc[j+1U] */
robert_lp 0:eedb7d567a5d 85 in = pSrc[2U * (i + 1U)];
robert_lp 0:eedb7d567a5d 86 pSrc[2U * (i + 1U)] = pSrc[2U * (j + fftLenBy2)];
robert_lp 0:eedb7d567a5d 87 pSrc[2U * (j + fftLenBy2)] = in;
robert_lp 0:eedb7d567a5d 88
robert_lp 0:eedb7d567a5d 89 /* pSrc[i+2U] <-> pSrc[j+2U] */
robert_lp 0:eedb7d567a5d 90 in = pSrc[(2U * (i + 1U)) + 1U];
robert_lp 0:eedb7d567a5d 91 pSrc[(2U * (i + 1U)) + 1U] = pSrc[(2U * (j + fftLenBy2)) + 1U];
robert_lp 0:eedb7d567a5d 92 pSrc[(2U * (j + fftLenBy2)) + 1U] = in;
robert_lp 0:eedb7d567a5d 93
robert_lp 0:eedb7d567a5d 94 /* Reading the index for the bit reversal */
robert_lp 0:eedb7d567a5d 95 j = *pBitRevTab;
robert_lp 0:eedb7d567a5d 96
robert_lp 0:eedb7d567a5d 97 /* Updating the bit reversal index depending on the fft length */
robert_lp 0:eedb7d567a5d 98 pBitRevTab += bitRevFactor;
robert_lp 0:eedb7d567a5d 99 }
robert_lp 0:eedb7d567a5d 100 }
robert_lp 0:eedb7d567a5d 101
robert_lp 0:eedb7d567a5d 102
robert_lp 0:eedb7d567a5d 103
robert_lp 0:eedb7d567a5d 104 /*
robert_lp 0:eedb7d567a5d 105 * @brief In-place bit reversal function.
robert_lp 0:eedb7d567a5d 106 * @param[in, out] *pSrc points to the in-place buffer of Q31 data type.
robert_lp 0:eedb7d567a5d 107 * @param[in] fftLen length of the FFT.
robert_lp 0:eedb7d567a5d 108 * @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table
robert_lp 0:eedb7d567a5d 109 * @param[in] *pBitRevTab points to bit reversal table.
robert_lp 0:eedb7d567a5d 110 * @return none.
robert_lp 0:eedb7d567a5d 111 */
robert_lp 0:eedb7d567a5d 112
robert_lp 0:eedb7d567a5d 113 void arm_bitreversal_q31(
robert_lp 0:eedb7d567a5d 114 q31_t * pSrc,
robert_lp 0:eedb7d567a5d 115 uint32_t fftLen,
robert_lp 0:eedb7d567a5d 116 uint16_t bitRevFactor,
robert_lp 0:eedb7d567a5d 117 uint16_t * pBitRevTable)
robert_lp 0:eedb7d567a5d 118 {
robert_lp 0:eedb7d567a5d 119 uint32_t fftLenBy2, fftLenBy2p1, i, j;
robert_lp 0:eedb7d567a5d 120 q31_t in;
robert_lp 0:eedb7d567a5d 121
robert_lp 0:eedb7d567a5d 122 /* Initializations */
robert_lp 0:eedb7d567a5d 123 j = 0U;
robert_lp 0:eedb7d567a5d 124 fftLenBy2 = fftLen / 2U;
robert_lp 0:eedb7d567a5d 125 fftLenBy2p1 = (fftLen / 2U) + 1U;
robert_lp 0:eedb7d567a5d 126
robert_lp 0:eedb7d567a5d 127 /* Bit Reversal Implementation */
robert_lp 0:eedb7d567a5d 128 for (i = 0U; i <= (fftLenBy2 - 2U); i += 2U)
robert_lp 0:eedb7d567a5d 129 {
robert_lp 0:eedb7d567a5d 130 if (i < j)
robert_lp 0:eedb7d567a5d 131 {
robert_lp 0:eedb7d567a5d 132 /* pSrc[i] <-> pSrc[j]; */
robert_lp 0:eedb7d567a5d 133 in = pSrc[2U * i];
robert_lp 0:eedb7d567a5d 134 pSrc[2U * i] = pSrc[2U * j];
robert_lp 0:eedb7d567a5d 135 pSrc[2U * j] = in;
robert_lp 0:eedb7d567a5d 136
robert_lp 0:eedb7d567a5d 137 /* pSrc[i+1U] <-> pSrc[j+1U] */
robert_lp 0:eedb7d567a5d 138 in = pSrc[(2U * i) + 1U];
robert_lp 0:eedb7d567a5d 139 pSrc[(2U * i) + 1U] = pSrc[(2U * j) + 1U];
robert_lp 0:eedb7d567a5d 140 pSrc[(2U * j) + 1U] = in;
robert_lp 0:eedb7d567a5d 141
robert_lp 0:eedb7d567a5d 142 /* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
robert_lp 0:eedb7d567a5d 143 in = pSrc[2U * (i + fftLenBy2p1)];
robert_lp 0:eedb7d567a5d 144 pSrc[2U * (i + fftLenBy2p1)] = pSrc[2U * (j + fftLenBy2p1)];
robert_lp 0:eedb7d567a5d 145 pSrc[2U * (j + fftLenBy2p1)] = in;
robert_lp 0:eedb7d567a5d 146
robert_lp 0:eedb7d567a5d 147 /* pSrc[i+fftLenBy2p1+1U] <-> pSrc[j+fftLenBy2p1+1U] */
robert_lp 0:eedb7d567a5d 148 in = pSrc[(2U * (i + fftLenBy2p1)) + 1U];
robert_lp 0:eedb7d567a5d 149 pSrc[(2U * (i + fftLenBy2p1)) + 1U] =
robert_lp 0:eedb7d567a5d 150 pSrc[(2U * (j + fftLenBy2p1)) + 1U];
robert_lp 0:eedb7d567a5d 151 pSrc[(2U * (j + fftLenBy2p1)) + 1U] = in;
robert_lp 0:eedb7d567a5d 152
robert_lp 0:eedb7d567a5d 153 }
robert_lp 0:eedb7d567a5d 154
robert_lp 0:eedb7d567a5d 155 /* pSrc[i+1U] <-> pSrc[j+1U] */
robert_lp 0:eedb7d567a5d 156 in = pSrc[2U * (i + 1U)];
robert_lp 0:eedb7d567a5d 157 pSrc[2U * (i + 1U)] = pSrc[2U * (j + fftLenBy2)];
robert_lp 0:eedb7d567a5d 158 pSrc[2U * (j + fftLenBy2)] = in;
robert_lp 0:eedb7d567a5d 159
robert_lp 0:eedb7d567a5d 160 /* pSrc[i+2U] <-> pSrc[j+2U] */
robert_lp 0:eedb7d567a5d 161 in = pSrc[(2U * (i + 1U)) + 1U];
robert_lp 0:eedb7d567a5d 162 pSrc[(2U * (i + 1U)) + 1U] = pSrc[(2U * (j + fftLenBy2)) + 1U];
robert_lp 0:eedb7d567a5d 163 pSrc[(2U * (j + fftLenBy2)) + 1U] = in;
robert_lp 0:eedb7d567a5d 164
robert_lp 0:eedb7d567a5d 165 /* Reading the index for the bit reversal */
robert_lp 0:eedb7d567a5d 166 j = *pBitRevTable;
robert_lp 0:eedb7d567a5d 167
robert_lp 0:eedb7d567a5d 168 /* Updating the bit reversal index depending on the fft length */
robert_lp 0:eedb7d567a5d 169 pBitRevTable += bitRevFactor;
robert_lp 0:eedb7d567a5d 170 }
robert_lp 0:eedb7d567a5d 171 }
robert_lp 0:eedb7d567a5d 172
robert_lp 0:eedb7d567a5d 173
robert_lp 0:eedb7d567a5d 174
robert_lp 0:eedb7d567a5d 175 /*
robert_lp 0:eedb7d567a5d 176 * @brief In-place bit reversal function.
robert_lp 0:eedb7d567a5d 177 * @param[in, out] *pSrc points to the in-place buffer of Q15 data type.
robert_lp 0:eedb7d567a5d 178 * @param[in] fftLen length of the FFT.
robert_lp 0:eedb7d567a5d 179 * @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table
robert_lp 0:eedb7d567a5d 180 * @param[in] *pBitRevTab points to bit reversal table.
robert_lp 0:eedb7d567a5d 181 * @return none.
robert_lp 0:eedb7d567a5d 182 */
robert_lp 0:eedb7d567a5d 183
robert_lp 0:eedb7d567a5d 184 void arm_bitreversal_q15(
robert_lp 0:eedb7d567a5d 185 q15_t * pSrc16,
robert_lp 0:eedb7d567a5d 186 uint32_t fftLen,
robert_lp 0:eedb7d567a5d 187 uint16_t bitRevFactor,
robert_lp 0:eedb7d567a5d 188 uint16_t * pBitRevTab)
robert_lp 0:eedb7d567a5d 189 {
robert_lp 0:eedb7d567a5d 190 q31_t *pSrc = (q31_t *) pSrc16;
robert_lp 0:eedb7d567a5d 191 q31_t in;
robert_lp 0:eedb7d567a5d 192 uint32_t fftLenBy2, fftLenBy2p1;
robert_lp 0:eedb7d567a5d 193 uint32_t i, j;
robert_lp 0:eedb7d567a5d 194
robert_lp 0:eedb7d567a5d 195 /* Initializations */
robert_lp 0:eedb7d567a5d 196 j = 0U;
robert_lp 0:eedb7d567a5d 197 fftLenBy2 = fftLen / 2U;
robert_lp 0:eedb7d567a5d 198 fftLenBy2p1 = (fftLen / 2U) + 1U;
robert_lp 0:eedb7d567a5d 199
robert_lp 0:eedb7d567a5d 200 /* Bit Reversal Implementation */
robert_lp 0:eedb7d567a5d 201 for (i = 0U; i <= (fftLenBy2 - 2U); i += 2U)
robert_lp 0:eedb7d567a5d 202 {
robert_lp 0:eedb7d567a5d 203 if (i < j)
robert_lp 0:eedb7d567a5d 204 {
robert_lp 0:eedb7d567a5d 205 /* pSrc[i] <-> pSrc[j]; */
robert_lp 0:eedb7d567a5d 206 /* pSrc[i+1U] <-> pSrc[j+1U] */
robert_lp 0:eedb7d567a5d 207 in = pSrc[i];
robert_lp 0:eedb7d567a5d 208 pSrc[i] = pSrc[j];
robert_lp 0:eedb7d567a5d 209 pSrc[j] = in;
robert_lp 0:eedb7d567a5d 210
robert_lp 0:eedb7d567a5d 211 /* pSrc[i + fftLenBy2p1] <-> pSrc[j + fftLenBy2p1]; */
robert_lp 0:eedb7d567a5d 212 /* pSrc[i + fftLenBy2p1+1U] <-> pSrc[j + fftLenBy2p1+1U] */
robert_lp 0:eedb7d567a5d 213 in = pSrc[i + fftLenBy2p1];
robert_lp 0:eedb7d567a5d 214 pSrc[i + fftLenBy2p1] = pSrc[j + fftLenBy2p1];
robert_lp 0:eedb7d567a5d 215 pSrc[j + fftLenBy2p1] = in;
robert_lp 0:eedb7d567a5d 216 }
robert_lp 0:eedb7d567a5d 217
robert_lp 0:eedb7d567a5d 218 /* pSrc[i+1U] <-> pSrc[j+fftLenBy2]; */
robert_lp 0:eedb7d567a5d 219 /* pSrc[i+2] <-> pSrc[j+fftLenBy2+1U] */
robert_lp 0:eedb7d567a5d 220 in = pSrc[i + 1U];
robert_lp 0:eedb7d567a5d 221 pSrc[i + 1U] = pSrc[j + fftLenBy2];
robert_lp 0:eedb7d567a5d 222 pSrc[j + fftLenBy2] = in;
robert_lp 0:eedb7d567a5d 223
robert_lp 0:eedb7d567a5d 224 /* Reading the index for the bit reversal */
robert_lp 0:eedb7d567a5d 225 j = *pBitRevTab;
robert_lp 0:eedb7d567a5d 226
robert_lp 0:eedb7d567a5d 227 /* Updating the bit reversal index depending on the fft length */
robert_lp 0:eedb7d567a5d 228 pBitRevTab += bitRevFactor;
robert_lp 0:eedb7d567a5d 229 }
robert_lp 0:eedb7d567a5d 230 }
robert_lp 0:eedb7d567a5d 231