1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_bitreversal2.c
4 * Description: Bitreversal functions
5 *
6 * $Date: 23 April 2021
7 * $Revision: V1.9.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2019 ARM Limited or its affiliates. All rights reserved.
13 *
14 * SPDX-License-Identifier: Apache-2.0
15 *
16 * Licensed under the Apache License, Version 2.0 (the License); you may
17 * not use this file except in compliance with the License.
18 * You may obtain a copy of the License at
19 *
20 * www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28
29 #include "dsp/transform_functions.h"
30 #include "arm_common_tables.h"
31
32 void arm_bitreversal_64(
33 uint64_t *pSrc,
34 const uint16_t bitRevLen,
35 const uint16_t *pBitRevTab);
36
37
38 /**
39 @brief In-place 64 bit reversal function.
40 @param[in,out] pSrc points to in-place buffer of unknown 64-bit data type
41 @param[in] bitRevLen bit reversal table length
42 @param[in] pBitRevTab points to bit reversal table
43 */
44
arm_bitreversal_64(uint64_t * pSrc,const uint16_t bitRevLen,const uint16_t * pBitRevTab)45 ARM_DSP_ATTRIBUTE void arm_bitreversal_64(
46 uint64_t *pSrc,
47 const uint16_t bitRevLen,
48 const uint16_t *pBitRevTab)
49 {
50 uint64_t a, b, tmp;
51 uint32_t i;
52
53 for (i = 0; i < bitRevLen; )
54 {
55 a = pBitRevTab[i ] >> 2;
56 b = pBitRevTab[i + 1] >> 2;
57
58 //real
59 tmp = pSrc[a];
60 pSrc[a] = pSrc[b];
61 pSrc[b] = tmp;
62
63 //complex
64 tmp = pSrc[a+1];
65 pSrc[a+1] = pSrc[b+1];
66 pSrc[b+1] = tmp;
67
68 i += 2;
69 }
70 }
71
72 void arm_bitreversal_32(
73 uint32_t *pSrc,
74 const uint16_t bitRevLen,
75 const uint16_t *pBitRevTab);
76
77 /**
78 @brief In-place 32 bit reversal function.
79 @param[in,out] pSrc points to in-place buffer of unknown 32-bit data type
80 @param[in] bitRevLen bit reversal table length
81 @param[in] pBitRevTab points to bit reversal table
82 */
83
arm_bitreversal_32(uint32_t * pSrc,const uint16_t bitRevLen,const uint16_t * pBitRevTab)84 ARM_DSP_ATTRIBUTE void arm_bitreversal_32(
85 uint32_t *pSrc,
86 const uint16_t bitRevLen,
87 const uint16_t *pBitRevTab)
88 {
89 uint32_t a, b, i, tmp;
90
91 for (i = 0; i < bitRevLen; )
92 {
93 a = pBitRevTab[i ] >> 2;
94 b = pBitRevTab[i + 1] >> 2;
95
96 //real
97 tmp = pSrc[a];
98 pSrc[a] = pSrc[b];
99 pSrc[b] = tmp;
100
101 //complex
102 tmp = pSrc[a+1];
103 pSrc[a+1] = pSrc[b+1];
104 pSrc[b+1] = tmp;
105
106 i += 2;
107 }
108 }
109
110 void arm_bitreversal_16(
111 uint16_t *pSrc,
112 const uint16_t bitRevLen,
113 const uint16_t *pBitRevTab);
114
115
116 /**
117 @brief In-place 16 bit reversal function.
118 @param[in,out] pSrc points to in-place buffer of unknown 16-bit data type
119 @param[in] bitRevLen bit reversal table length
120 @param[in] pBitRevTab points to bit reversal table
121 */
122
arm_bitreversal_16(uint16_t * pSrc,const uint16_t bitRevLen,const uint16_t * pBitRevTab)123 ARM_DSP_ATTRIBUTE void arm_bitreversal_16(
124 uint16_t *pSrc,
125 const uint16_t bitRevLen,
126 const uint16_t *pBitRevTab)
127 {
128 uint16_t a, b, tmp;
129 uint32_t i;
130
131 for (i = 0; i < bitRevLen; )
132 {
133 a = pBitRevTab[i ] >> 2;
134 b = pBitRevTab[i + 1] >> 2;
135
136 //real
137 tmp = pSrc[a];
138 pSrc[a] = pSrc[b];
139 pSrc[b] = tmp;
140
141 //complex
142 tmp = pSrc[a+1];
143 pSrc[a+1] = pSrc[b+1];
144 pSrc[b+1] = tmp;
145
146 i += 2;
147 }
148 }
149
