1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_cmplx_conj_f16.c
4 * Description: Floating-point 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_f16.h"
30
31 #if defined(ARM_FLOAT16_SUPPORTED)
32 /**
33 @ingroup groupCmplxMath
34 */
35
36 /**
37 @defgroup cmplx_conj Complex Conjugate
38
39 Conjugates the elements of a complex data vector.
40
41 The <code>pSrc</code> points to the source data and
42 <code>pDst</code> points to the destination data where the result should be written.
43 <code>numSamples</code> specifies the number of complex samples
44 and the data in each array is stored in an interleaved fashion
45 (real, imag, real, imag, ...).
46 Each array has a total of <code>2*numSamples</code> values.
47
48 The underlying algorithm is used:
49 <pre>
50 for (n = 0; n < numSamples; n++) {
51 pDst[(2*n) ] = pSrc[(2*n) ]; // real part
52 pDst[(2*n)+1] = -pSrc[(2*n)+1]; // imag part
53 }
54 </pre>
55
56 There are separate functions for floating-point, Q15, and Q31 data types.
57 */
58
59 /**
60 @addtogroup cmplx_conj
61 @{
62 */
63
64 /**
65 @brief Floating-point complex conjugate.
66 @param[in] pSrc points to the input vector
67 @param[out] pDst points to the output vector
68 @param[in] numSamples number of samples in each vector
69 @return none
70 */
71
72 #if defined(ARM_MATH_MVE_FLOAT16) && !defined(ARM_MATH_AUTOVECTORIZE)
73
arm_cmplx_conj_f16(const float16_t * pSrc,float16_t * pDst,uint32_t numSamples)74 void arm_cmplx_conj_f16(
75 const float16_t * pSrc,
76 float16_t * pDst,
77 uint32_t numSamples)
78 {
79 static const float16_t cmplx_conj_sign[8] = { 1.0f, -1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f, -1.0f };
80 uint32_t blockSize = numSamples * CMPLX_DIM; /* loop counters */
81 uint32_t blkCnt;
82 f16x8_t vecSrc;
83 f16x8_t vecSign;
84
85 /*
86 * load sign vector
87 */
88 vecSign = *(f16x8_t *) cmplx_conj_sign;
89
90 /* Compute 4 real samples at a time */
91 blkCnt = blockSize >> 3U;
92
93 while (blkCnt > 0U)
94 {
95 vecSrc = vld1q(pSrc);
96 vst1q(pDst,vmulq(vecSrc, vecSign));
97 /*
98 * Decrement the blkCnt loop counter
99 * Advance vector source and destination pointers
100 */
101 pSrc += 8;
102 pDst += 8;
103 blkCnt--;
104 }
105
106 /* Tail */
107 blkCnt = (blockSize & 0x7) >> 1;
108
109 while (blkCnt > 0U)
110 {
111 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
112
113 /* Calculate Complex Conjugate and store result in destination buffer. */
114 *pDst++ = *pSrc++;
115 *pDst++ = -*pSrc++;
116
117 /* Decrement loop counter */
118 blkCnt--;
119 }
120
121 }
122
123 #else
arm_cmplx_conj_f16(const float16_t * pSrc,float16_t * pDst,uint32_t numSamples)124 void arm_cmplx_conj_f16(
125 const float16_t * pSrc,
126 float16_t * pDst,
127 uint32_t numSamples)
128 {
129 uint32_t blkCnt; /* Loop counter */
130
131 #if defined (ARM_MATH_LOOPUNROLL) && !defined(ARM_MATH_AUTOVECTORIZE)
132
133 /* Loop unrolling: Compute 4 outputs at a time */
134 blkCnt = numSamples >> 2U;
135
136 while (blkCnt > 0U)
137 {
138 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
139
140 /* Calculate Complex Conjugate and store result in destination buffer. */
141 *pDst++ = *pSrc++;
142 *pDst++ = -*pSrc++;
143
144 *pDst++ = *pSrc++;
145 *pDst++ = -*pSrc++;
146
147 *pDst++ = *pSrc++;
148 *pDst++ = -*pSrc++;
149
150 *pDst++ = *pSrc++;
151 *pDst++ = -*pSrc++;
152
153 /* Decrement loop counter */
154 blkCnt--;
155 }
156
157 /* Loop unrolling: Compute remaining outputs */
158 blkCnt = numSamples % 0x4U;
159
160 #else
161
162 /* Initialize blkCnt with number of samples */
163 blkCnt = numSamples;
164
165 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
166
167 while (blkCnt > 0U)
168 {
169 /* C[0] + jC[1] = A[0]+ j(-1)A[1] */
170
171 /* Calculate Complex Conjugate and store result in destination buffer. */
172 *pDst++ = *pSrc++;
173 *pDst++ = -*pSrc++;
174
175 /* Decrement loop counter */
176 blkCnt--;
177 }
178
179 }
180 #endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */
181
182 /**
183 @} end of cmplx_conj group
184 */
185 #endif /* #if defined(ARM_FLOAT16_SUPPORTED) */
