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 @return none
46
47 @par Scaling and Overflow Behavior
48 The function uses saturating arithmetic.
49 The Q31 value -1 (0x80000000) is saturated to the maximum allowable positive value 0x7FFFFFFF.
50 */
51
52 #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
53
arm_cmplx_conj_q31(const q31_t * pSrc,q31_t * pDst,uint32_t numSamples)54 void arm_cmplx_conj_q31(
55 const q31_t * pSrc,
56 q31_t * pDst,
57 uint32_t numSamples)
58 {
59
60 uint32_t blockSize = numSamples * CMPLX_DIM; /* loop counters */
61 uint32_t blkCnt;
62 q31x4x2_t vecSrc;
63 q31_t in; /* Temporary input variable */
64 q31x4_t zero;
65
66 zero = vdupq_n_s32(0);
67
68
69 /* Compute 4 real samples at a time */
70 blkCnt = blockSize >> 3U;
71
72 while (blkCnt > 0U)
73 {
74
75 vecSrc = vld2q(pSrc);
76 vecSrc.val[1] = vqsubq(zero, vecSrc.val[1]);
77 vst2q(pDst,vecSrc);
78 /*
79 * Decrement the blkCnt loop counter
80 * Advance vector source and destination pointers
81 */
82 pSrc += 8;
83 pDst += 8;
84 blkCnt --;
85 }
86
87 /* Tail */
88 blkCnt = (blockSize & 0x7) >> 1;
89
90 while (blkCnt > 0U)
91 {
92 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
93
94 /* Calculate Complex Conjugate and store result in destination buffer. */
95 *pDst++ = *pSrc++;
96 in = *pSrc++;
97 *pDst++ = __QSUB(0, in);
98
99 /* Decrement loop counter */
100 blkCnt--;
101 }
102
103
104 }
105 #else
106
arm_cmplx_conj_q31(const q31_t * pSrc,q31_t * pDst,uint32_t numSamples)107 void arm_cmplx_conj_q31(
108 const q31_t * pSrc,
109 q31_t * pDst,
110 uint32_t numSamples)
111 {
112 uint32_t blkCnt; /* Loop counter */
113 q31_t in; /* Temporary input variable */
114
115 #if defined (ARM_MATH_LOOPUNROLL)
116
117 /* Loop unrolling: Compute 4 outputs at a time */
118 blkCnt = numSamples >> 2U;
119
120 while (blkCnt > 0U)
121 {
122 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
123
124 /* Calculate Complex Conjugate and store result in destination buffer. */
125 *pDst++ = *pSrc++;
126 in = *pSrc++;
127 #if defined (ARM_MATH_DSP)
128 *pDst++ = __QSUB(0, in);
129 #else
130 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
131 #endif
132
133 *pDst++ = *pSrc++;
134 in = *pSrc++;
135 #if defined (ARM_MATH_DSP)
136 *pDst++ = __QSUB(0, in);
137 #else
138 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
139 #endif
140
141 *pDst++ = *pSrc++;
142 in = *pSrc++;
143 #if defined (ARM_MATH_DSP)
144 *pDst++ = __QSUB(0, in);
145 #else
146 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
147 #endif
148
149 *pDst++ = *pSrc++;
150 in = *pSrc++;
151 #if defined (ARM_MATH_DSP)
152 *pDst++ = __QSUB(0, in);
153 #else
154 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
155 #endif
156
157 /* Decrement loop counter */
158 blkCnt--;
159 }
160
161 /* Loop unrolling: Compute remaining outputs */
162 blkCnt = numSamples % 0x4U;
163
164 #else
165
166 /* Initialize blkCnt with number of samples */
167 blkCnt = numSamples;
168
169 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
170
171 while (blkCnt > 0U)
172 {
173 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
174
175 /* Calculate Complex Conjugate and store result in destination buffer. */
176 *pDst++ = *pSrc++;
177 in = *pSrc++;
178 #if defined (ARM_MATH_DSP)
179 *pDst++ = __QSUB(0, in);
180 #else
181 *pDst++ = (in == INT32_MIN) ? INT32_MAX : -in;
182 #endif
183
184 /* Decrement loop counter */
185 blkCnt--;
186 }
187
188 }
189 #endif /* defined(ARM_MATH_MVEI) */
190
191 /**
192 @} end of cmplx_conj group
193 */
194
