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| Rev | Author | Line No. | Line |
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| 56 | mjames | 1 | /* ---------------------------------------------------------------------- |
| 2 | * Project: CMSIS DSP Library |
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| 3 | * Title: arm_cmplx_mag_q31.c |
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| 4 | * Description: Q31 complex magnitude |
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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 | * @addtogroup cmplx_mag |
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| 37 | * @{ |
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| 38 | */ |
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| 39 | |||
| 40 | /** |
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| 41 | * @brief Q31 complex magnitude |
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| 42 | * @param *pSrc points to the complex input vector |
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| 43 | * @param *pDst points to the real output vector |
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| 44 | * @param numSamples number of complex samples in the input vector |
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| 45 | * @return none. |
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| 46 | * |
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| 47 | * <b>Scaling and Overflow Behavior:</b> |
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| 48 | * \par |
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| 49 | * The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format. |
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| 50 | * Input down scaling is not required. |
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| 51 | */ |
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| 52 | |||
| 53 | void arm_cmplx_mag_q31( |
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| 54 | q31_t * pSrc, |
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| 55 | q31_t * pDst, |
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| 56 | uint32_t numSamples) |
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| 57 | { |
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| 58 | q31_t real, imag; /* Temporary variables to hold input values */ |
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| 59 | q31_t acc0, acc1; /* Accumulators */ |
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| 60 | uint32_t blkCnt; /* loop counter */ |
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| 61 | |||
| 62 | #if defined (ARM_MATH_DSP) |
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| 63 | |||
| 64 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
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| 65 | q31_t real1, real2, imag1, imag2; /* Temporary variables to hold input values */ |
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| 66 | q31_t out1, out2, out3, out4; /* Accumulators */ |
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| 67 | q63_t mul1, mul2, mul3, mul4; /* Temporary variables */ |
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| 68 | |||
| 69 | |||
| 70 | /*loop Unrolling */ |
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| 71 | blkCnt = numSamples >> 2U; |
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| 72 | |||
| 73 | /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
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| 74 | ** a second loop below computes the remaining 1 to 3 samples. */ |
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| 75 | while (blkCnt > 0U) |
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| 76 | { |
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| 77 | /* read complex input from source buffer */ |
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| 78 | real1 = pSrc[0]; |
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| 79 | imag1 = pSrc[1]; |
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| 80 | real2 = pSrc[2]; |
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| 81 | imag2 = pSrc[3]; |
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| 82 | |||
| 83 | /* calculate power of input values */ |
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| 84 | mul1 = (q63_t) real1 *real1; |
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| 85 | mul2 = (q63_t) imag1 *imag1; |
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| 86 | mul3 = (q63_t) real2 *real2; |
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| 87 | mul4 = (q63_t) imag2 *imag2; |
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| 88 | |||
| 89 | /* get the result to 3.29 format */ |
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| 90 | out1 = (q31_t) (mul1 >> 33); |
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| 91 | out2 = (q31_t) (mul2 >> 33); |
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| 92 | out3 = (q31_t) (mul3 >> 33); |
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| 93 | out4 = (q31_t) (mul4 >> 33); |
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| 94 | |||
| 95 | /* add real and imaginary accumulators */ |
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| 96 | out1 = out1 + out2; |
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| 97 | out3 = out3 + out4; |
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| 98 | |||
| 99 | /* read complex input from source buffer */ |
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| 100 | real1 = pSrc[4]; |
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| 101 | imag1 = pSrc[5]; |
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| 102 | real2 = pSrc[6]; |
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| 103 | imag2 = pSrc[7]; |
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| 104 | |||
| 105 | /* calculate square root */ |
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| 106 | arm_sqrt_q31(out1, &pDst[0]); |
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| 107 | |||
| 108 | /* calculate power of input values */ |
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| 109 | mul1 = (q63_t) real1 *real1; |
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| 110 | |||
| 111 | /* calculate square root */ |
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| 112 | arm_sqrt_q31(out3, &pDst[1]); |
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| 113 | |||
| 114 | /* calculate power of input values */ |
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| 115 | mul2 = (q63_t) imag1 *imag1; |
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| 116 | mul3 = (q63_t) real2 *real2; |
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| 117 | mul4 = (q63_t) imag2 *imag2; |
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| 118 | |||
| 119 | /* get the result to 3.29 format */ |
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| 120 | out1 = (q31_t) (mul1 >> 33); |
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| 121 | out2 = (q31_t) (mul2 >> 33); |
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| 122 | out3 = (q31_t) (mul3 >> 33); |
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| 123 | out4 = (q31_t) (mul4 >> 33); |
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| 124 | |||
| 125 | /* add real and imaginary accumulators */ |
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| 126 | out1 = out1 + out2; |
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| 127 | out3 = out3 + out4; |
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| 128 | |||
| 129 | /* calculate square root */ |
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| 130 | arm_sqrt_q31(out1, &pDst[2]); |
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| 131 | |||
| 132 | /* increment destination by 8 to process next samples */ |
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| 133 | pSrc += 8U; |
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| 134 | |||
| 135 | /* calculate square root */ |
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| 136 | arm_sqrt_q31(out3, &pDst[3]); |
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| 137 | |||
| 138 | /* increment destination by 4 to process next samples */ |
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| 139 | pDst += 4U; |
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| 140 | |||
| 141 | /* Decrement the loop counter */ |
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| 142 | blkCnt--; |
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| 143 | } |
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| 144 | |||
| 145 | /* If the numSamples is not a multiple of 4, compute any remaining output samples here. |
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| 146 | ** No loop unrolling is used. */ |
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| 147 | blkCnt = numSamples % 0x4U; |
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| 148 | |||
| 149 | #else |
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| 150 | |||
| 151 | /* Run the below code for Cortex-M0 */ |
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| 152 | blkCnt = numSamples; |
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| 153 | |||
| 154 | #endif /* #if defined (ARM_MATH_DSP) */ |
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| 155 | |||
| 156 | while (blkCnt > 0U) |
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| 157 | { |
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| 158 | /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */ |
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| 159 | real = *pSrc++; |
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| 160 | imag = *pSrc++; |
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| 161 | acc0 = (q31_t) (((q63_t) real * real) >> 33); |
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| 162 | acc1 = (q31_t) (((q63_t) imag * imag) >> 33); |
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| 163 | /* store the result in 2.30 format in the destination buffer. */ |
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| 164 | arm_sqrt_q31(acc0 + acc1, pDst++); |
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| 165 | |||
| 166 | /* Decrement the loop counter */ |
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| 167 | blkCnt--; |
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| 168 | } |
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| 169 | } |
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| 170 | |||
| 171 | /** |
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| 172 | * @} end of cmplx_mag group |
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| 173 | */ |