1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_cmplx_conj_q31.c
4 * Description: Q31 complex conjugate
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) 2010-2021 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/complex_math_functions.h"
30
31 /**
32 @ingroup groupCmplxMath
33 */
34
35 /**
36 @addtogroup cmplx_conj
37 @{
38 */
39
40 /**
41 @brief Q31 complex conjugate.
42 @param[in] pSrc points to the input vector
43 @param[out] pDst points to the output vector
44 @param[in] numSamples number of samples in each vector
45
46 @par Scaling and Overflow Behavior
47 The function uses saturating arithmetic.
48 The Q31 value -1 (0x80000000) is saturated to the maximum allowable positive value 0x7FFFFFFF.
49 */
50
51 #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
52
arm_cmplx_conj_q31(const q31_t * pSrc,q31_t * pDst,uint32_t numSamples)53 ARM_DSP_ATTRIBUTE void arm_cmplx_conj_q31(
54 const q31_t * pSrc,
55 q31_t * pDst,
56 uint32_t numSamples)
57 {
58
59 uint32_t blockSize = numSamples * CMPLX_DIM; /* loop counters */
60 uint32_t blkCnt;
61 q31x4x2_t vecSrc;
62 q31_t in; /* Temporary input variable */
63 q31x4_t zero;
64
65 zero = vdupq_n_s32(0);
66
67
68 /* Compute 4 real samples at a time */
69 blkCnt = blockSize >> 3U;
70
71 while (blkCnt > 0U)
72 {
73
74 vecSrc = vld2q(pSrc);
75 vecSrc.val[1] = vqsubq(zero, vecSrc.val[1]);
76 vst2q(pDst,vecSrc);
77 /*
78 * Decrement the blkCnt loop counter
79 * Advance vector source and destination pointers
80 */
81 pSrc += 8;
82 pDst += 8;
83 blkCnt --;
84 }
85
86 /* Tail */
87 blkCnt = (blockSize & 0x7) >> 1;
88
89 while (blkCnt > 0U)
90 {
91 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
92
93 /* Calculate Complex Conjugate and store result in destination buffer. */
94 *pDst++ = *pSrc++;
95 in = *pSrc++;
96 *pDst++ = __QSUB(0, in);
97
98 /* Decrement loop counter */
99 blkCnt--;
100 }
101
102
103 }
104 #else
105
arm_cmplx_conj_q31(const q31_t * pSrc,q31_t * pDst,uint32_t numSamples)106 ARM_DSP_ATTRIBUTE void arm_cmplx_conj_q31(
107 const q31_t * pSrc,
108 q31_t * pDst,
109 uint32_t numSamples)
110 {
111 uint32_t blkCnt; /* Loop counter */
112 q31_t in; /* Temporary input variable */
113
114 #if defined (ARM_MATH_LOOPUNROLL)
115
116 /* Loop unrolling: Compute 4 outputs at a time */
117 blkCnt = numSamples >> 2U;
118
119 while (blkCnt > 0U)
120 {
121 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
122
123 /* Calculate Complex Conjugate and store result in destination buffer. */
124 *pDst++ = *pSrc++;
125 in = *pSrc++;
126 #if defined (ARM_MATH_DSP)
127 *pDst++ = __QSUB(0, in);
128 #else
129 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
130 #endif
131
132 *pDst++ = *pSrc++;
133 in = *pSrc++;
134 #if defined (ARM_MATH_DSP)
135 *pDst++ = __QSUB(0, in);
136 #else
137 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
138 #endif
139
140 *pDst++ = *pSrc++;
141 in = *pSrc++;
142 #if defined (ARM_MATH_DSP)
143 *pDst++ = __QSUB(0, in);
144 #else
145 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
146 #endif
147
148 *pDst++ = *pSrc++;
149 in = *pSrc++;
150 #if defined (ARM_MATH_DSP)
151 *pDst++ = __QSUB(0, in);
152 #else
153 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
154 #endif
155
156 /* Decrement loop counter */
157 blkCnt--;
158 }
159
160 /* Loop unrolling: Compute remaining outputs */
161 blkCnt = numSamples % 0x4U;
162
163 #else
164
165 /* Initialize blkCnt with number of samples */
166 blkCnt = numSamples;
167
168 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
169
170 while (blkCnt > 0U)
171 {
172 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
173
174 /* Calculate Complex Conjugate and store result in destination buffer. */
175 *pDst++ = *pSrc++;
176 in = *pSrc++;
177 #if defined (ARM_MATH_DSP)
178 *pDst++ = __QSUB(0, in);
179 #else
180 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
181 #endif
182
183 /* Decrement loop counter */
184 blkCnt--;
185 }
186
187 }
188 #endif /* defined(ARM_MATH_MVEI) */
189
190 /**
191 @} end of cmplx_conj group
192 */
193
