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| 56 | mjames | 1 | /* ---------------------------------------------------------------------- |
| 2 | * Project: CMSIS DSP Library |
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| 3 | * Title: arm_cmplx_conj_q15.c |
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| 4 | * Description: Q15 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 | * @addtogroup cmplx_conj |
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| 37 | * @{ |
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| 38 | */ |
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| 39 | |||
| 40 | /** |
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| 41 | * @brief Q15 complex conjugate. |
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| 42 | * @param *pSrc points to the input vector |
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| 43 | * @param *pDst points to the output vector |
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| 44 | * @param numSamples number of complex samples in each 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 uses saturating arithmetic. |
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| 50 | * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF. |
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| 51 | */ |
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| 52 | |||
| 53 | void arm_cmplx_conj_q15( |
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| 54 | q15_t * pSrc, |
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| 55 | q15_t * pDst, |
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| 56 | uint32_t numSamples) |
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| 57 | { |
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| 58 | |||
| 59 | #if defined (ARM_MATH_DSP) |
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| 60 | |||
| 61 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
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| 62 | uint32_t blkCnt; /* loop counter */ |
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| 63 | q31_t in1, in2, in3, in4; |
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| 64 | q31_t zero = 0; |
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| 65 | |||
| 66 | /*loop Unrolling */ |
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| 67 | blkCnt = numSamples >> 2U; |
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| 68 | |||
| 69 | /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
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| 70 | ** a second loop below computes the remaining 1 to 3 samples. */ |
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| 71 | while (blkCnt > 0U) |
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| 72 | { |
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| 73 | /* C[0]+jC[1] = A[0]+ j (-1) A[1] */ |
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| 74 | /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
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| 75 | in1 = *__SIMD32(pSrc)++; |
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| 76 | in2 = *__SIMD32(pSrc)++; |
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| 77 | in3 = *__SIMD32(pSrc)++; |
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| 78 | in4 = *__SIMD32(pSrc)++; |
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| 79 | |||
| 80 | #ifndef ARM_MATH_BIG_ENDIAN |
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| 81 | |||
| 82 | in1 = __QASX(zero, in1); |
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| 83 | in2 = __QASX(zero, in2); |
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| 84 | in3 = __QASX(zero, in3); |
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| 85 | in4 = __QASX(zero, in4); |
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| 86 | |||
| 87 | #else |
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| 88 | |||
| 89 | in1 = __QSAX(zero, in1); |
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| 90 | in2 = __QSAX(zero, in2); |
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| 91 | in3 = __QSAX(zero, in3); |
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| 92 | in4 = __QSAX(zero, in4); |
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| 93 | |||
| 94 | #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ |
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| 95 | |||
| 96 | in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16); |
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| 97 | in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16); |
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| 98 | in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16); |
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| 99 | in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16); |
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| 100 | |||
| 101 | *__SIMD32(pDst)++ = in1; |
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| 102 | *__SIMD32(pDst)++ = in2; |
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| 103 | *__SIMD32(pDst)++ = in3; |
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| 104 | *__SIMD32(pDst)++ = in4; |
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| 105 | |||
| 106 | /* Decrement the loop counter */ |
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| 107 | blkCnt--; |
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| 108 | } |
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| 109 | |||
| 110 | /* If the numSamples is not a multiple of 4, compute any remaining output samples here. |
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| 111 | ** No loop unrolling is used. */ |
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| 112 | blkCnt = numSamples % 0x4U; |
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| 113 | |||
| 114 | while (blkCnt > 0U) |
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| 115 | { |
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| 116 | /* C[0]+jC[1] = A[0]+ j (-1) A[1] */ |
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| 117 | /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
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| 118 | *pDst++ = *pSrc++; |
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| 119 | *pDst++ = __SSAT(-*pSrc++, 16); |
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| 120 | |||
| 121 | /* Decrement the loop counter */ |
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| 122 | blkCnt--; |
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| 123 | } |
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| 124 | |||
| 125 | #else |
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| 126 | |||
| 127 | q15_t in; |
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| 128 | |||
| 129 | /* Run the below code for Cortex-M0 */ |
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| 130 | |||
| 131 | while (numSamples > 0U) |
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| 132 | { |
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| 133 | /* realOut + j (imagOut) = realIn+ j (-1) imagIn */ |
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| 134 | /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
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| 135 | *pDst++ = *pSrc++; |
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| 136 | in = *pSrc++; |
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| 137 | *pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in; |
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| 138 | |||
| 139 | /* Decrement the loop counter */ |
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| 140 | numSamples--; |
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| 141 | } |
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| 142 | |||
| 143 | #endif /* #if defined (ARM_MATH_DSP) */ |
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| 144 | |||
| 145 | } |
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| 146 | |||
| 147 | /** |
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| 148 | * @} end of cmplx_conj group |
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| 149 | */ |