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| 56 | mjames | 1 | /* ---------------------------------------------------------------------- |
| 2 | * Project: CMSIS DSP Library |
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| 3 | * Title: arm_cmplx_conj_f32.c |
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| 4 | * Description: Floating-point complex conjugate |
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| 5 | * |
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| 6 | * $Date: 27. January 2017 |
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| 7 | * $Revision: V.1.5.1 |
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| 8 | * |
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| 9 | * Target Processor: Cortex-M cores |
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| 10 | * -------------------------------------------------------------------- */ |
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| 11 | /* |
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| 12 | * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. |
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| 13 | * |
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| 14 | * SPDX-License-Identifier: Apache-2.0 |
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| 15 | * |
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| 16 | * Licensed under the Apache License, Version 2.0 (the License); you may |
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| 17 | * not use this file except in compliance with the License. |
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| 18 | * You may obtain a copy of the License at |
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| 19 | * |
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| 20 | * www.apache.org/licenses/LICENSE-2.0 |
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| 21 | * |
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| 22 | * Unless required by applicable law or agreed to in writing, software |
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| 23 | * distributed under the License is distributed on an AS IS BASIS, WITHOUT |
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| 24 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 25 | * See the License for the specific language governing permissions and |
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| 26 | * limitations under the License. |
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| 27 | */ |
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| 28 | |||
| 29 | #include "arm_math.h" |
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| 30 | |||
| 31 | /** |
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| 32 | * @ingroup groupCmplxMath |
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| 33 | */ |
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| 34 | |||
| 35 | /** |
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| 36 | * @defgroup cmplx_conj Complex Conjugate |
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| 37 | * |
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| 38 | * Conjugates the elements of a complex data vector. |
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| 39 | * |
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| 40 | * The <code>pSrc</code> points to the source data and |
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| 41 | * <code>pDst</code> points to the where the result should be written. |
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| 42 | * <code>numSamples</code> specifies the number of complex samples |
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| 43 | * and the data in each array is stored in an interleaved fashion |
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| 44 | * (real, imag, real, imag, ...). |
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| 45 | * Each array has a total of <code>2*numSamples</code> values. |
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| 46 | * The underlying algorithm is used: |
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| 47 | * |
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| 48 | * <pre> |
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| 49 | * for(n=0; n<numSamples; n++) { |
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| 50 | * pDst[(2*n)+0)] = pSrc[(2*n)+0]; // real part |
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| 51 | * pDst[(2*n)+1)] = -pSrc[(2*n)+1]; // imag part |
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| 52 | * } |
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| 53 | * </pre> |
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| 54 | * |
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| 55 | * There are separate functions for floating-point, Q15, and Q31 data types. |
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| 56 | */ |
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| 57 | |||
| 58 | /** |
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| 59 | * @addtogroup cmplx_conj |
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| 60 | * @{ |
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| 61 | */ |
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| 62 | |||
| 63 | /** |
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| 64 | * @brief Floating-point complex conjugate. |
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| 65 | * @param *pSrc points to the input vector |
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| 66 | * @param *pDst points to the output vector |
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| 67 | * @param numSamples number of complex samples in each vector |
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| 68 | * @return none. |
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| 69 | */ |
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| 70 | |||
| 71 | void arm_cmplx_conj_f32( |
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| 72 | float32_t * pSrc, |
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| 73 | float32_t * pDst, |
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| 74 | uint32_t numSamples) |
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| 75 | { |
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| 76 | uint32_t blkCnt; /* loop counter */ |
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| 77 | |||
| 78 | #if defined (ARM_MATH_DSP) |
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| 79 | |||
| 80 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
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| 81 | float32_t inR1, inR2, inR3, inR4; |
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| 82 | float32_t inI1, inI2, inI3, inI4; |
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| 83 | |||
| 84 | /*loop Unrolling */ |
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| 85 | blkCnt = numSamples >> 2U; |
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| 86 | |||
| 87 | /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
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| 88 | ** a second loop below computes the remaining 1 to 3 samples. */ |
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| 89 | while (blkCnt > 0U) |
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| 90 | { |
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| 91 | /* C[0]+jC[1] = A[0]+ j (-1) A[1] */ |
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| 92 | /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
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| 93 | /* read real input samples */ |
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| 94 | inR1 = pSrc[0]; |
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| 95 | /* store real samples to destination */ |
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| 96 | pDst[0] = inR1; |
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| 97 | inR2 = pSrc[2]; |
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| 98 | pDst[2] = inR2; |
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| 99 | inR3 = pSrc[4]; |
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| 100 | pDst[4] = inR3; |
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| 101 | inR4 = pSrc[6]; |
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| 102 | pDst[6] = inR4; |
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| 103 | |||
| 104 | /* read imaginary input samples */ |
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| 105 | inI1 = pSrc[1]; |
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| 106 | inI2 = pSrc[3]; |
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| 107 | |||
| 108 | /* conjugate input */ |
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| 109 | inI1 = -inI1; |
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| 110 | |||
| 111 | /* read imaginary input samples */ |
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| 112 | inI3 = pSrc[5]; |
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| 113 | |||
| 114 | /* conjugate input */ |
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| 115 | inI2 = -inI2; |
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| 116 | |||
| 117 | /* read imaginary input samples */ |
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| 118 | inI4 = pSrc[7]; |
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| 119 | |||
| 120 | /* conjugate input */ |
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| 121 | inI3 = -inI3; |
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| 122 | |||
| 123 | /* store imaginary samples to destination */ |
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| 124 | pDst[1] = inI1; |
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| 125 | pDst[3] = inI2; |
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| 126 | |||
| 127 | /* conjugate input */ |
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| 128 | inI4 = -inI4; |
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| 129 | |||
| 130 | /* store imaginary samples to destination */ |
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| 131 | pDst[5] = inI3; |
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| 132 | |||
| 133 | /* increment source pointer by 8 to process next sampels */ |
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| 134 | pSrc += 8U; |
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| 135 | |||
| 136 | /* store imaginary sample to destination */ |
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| 137 | pDst[7] = inI4; |
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| 138 | |||
| 139 | /* increment destination pointer by 8 to store next samples */ |
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| 140 | pDst += 8U; |
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| 141 | |||
| 142 | /* Decrement the loop counter */ |
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| 143 | blkCnt--; |
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| 144 | } |
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| 145 | |||
| 146 | /* If the numSamples is not a multiple of 4, compute any remaining output samples here. |
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| 147 | ** No loop unrolling is used. */ |
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| 148 | blkCnt = numSamples % 0x4U; |
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| 149 | |||
| 150 | #else |
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| 151 | |||
| 152 | /* Run the below code for Cortex-M0 */ |
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| 153 | blkCnt = numSamples; |
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| 154 | |||
| 155 | #endif /* #if defined (ARM_MATH_DSP) */ |
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| 156 | |||
| 157 | while (blkCnt > 0U) |
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| 158 | { |
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| 159 | /* realOut + j (imagOut) = realIn + j (-1) imagIn */ |
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| 160 | /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
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| 161 | *pDst++ = *pSrc++; |
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| 162 | *pDst++ = -*pSrc++; |
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| 163 | |||
| 164 | /* Decrement the loop counter */ |
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| 165 | blkCnt--; |
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| 166 | } |
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| 167 | } |
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| 168 | |||
| 169 | /** |
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| 170 | * @} end of cmplx_conj group |
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| 171 | */ |