Rev 2 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | mjames | 1 | /* ---------------------------------------------------------------------- |
| 2 | * Project: CMSIS DSP Library |
||
| 3 | * Title: arm_cmplx_mag_squared_q31.c |
||
| 4 | * Description: Q31 complex magnitude squared |
||
| 5 | * |
||
| 6 | * $Date: 27. January 2017 |
||
| 7 | * $Revision: V.1.5.1 |
||
| 8 | * |
||
| 9 | * Target Processor: Cortex-M cores |
||
| 10 | * -------------------------------------------------------------------- */ |
||
| 11 | /* |
||
| 12 | * Copyright (C) 2010-2017 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 "arm_math.h" |
||
| 30 | |||
| 31 | /** |
||
| 32 | * @ingroup groupCmplxMath |
||
| 33 | */ |
||
| 34 | |||
| 35 | /** |
||
| 36 | * @addtogroup cmplx_mag_squared |
||
| 37 | * @{ |
||
| 38 | */ |
||
| 39 | |||
| 40 | |||
| 41 | /** |
||
| 42 | * @brief Q31 complex magnitude squared |
||
| 43 | * @param *pSrc points to the complex input vector |
||
| 44 | * @param *pDst points to the real output vector |
||
| 45 | * @param numSamples number of complex samples in the input vector |
||
| 46 | * @return none. |
||
| 47 | * |
||
| 48 | * <b>Scaling and Overflow Behavior:</b> |
||
| 49 | * \par |
||
| 50 | * The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format. |
||
| 51 | * Input down scaling is not required. |
||
| 52 | */ |
||
| 53 | |||
| 54 | void arm_cmplx_mag_squared_q31( |
||
| 55 | q31_t * pSrc, |
||
| 56 | q31_t * pDst, |
||
| 57 | uint32_t numSamples) |
||
| 58 | { |
||
| 59 | q31_t real, imag; /* Temporary variables to store real and imaginary values */ |
||
| 60 | q31_t acc0, acc1; /* Accumulators */ |
||
| 61 | |||
| 62 | #if defined (ARM_MATH_DSP) |
||
| 63 | |||
| 64 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
||
| 65 | uint32_t blkCnt; /* loop counter */ |
||
| 66 | |||
| 67 | /* loop Unrolling */ |
||
| 68 | blkCnt = numSamples >> 2U; |
||
| 69 | |||
| 70 | /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
||
| 71 | ** a second loop below computes the remaining 1 to 3 samples. */ |
||
| 72 | while (blkCnt > 0U) |
||
| 73 | { |
||
| 74 | /* C[0] = (A[0] * A[0] + A[1] * A[1]) */ |
||
| 75 | real = *pSrc++; |
||
| 76 | imag = *pSrc++; |
||
| 77 | acc0 = (q31_t) (((q63_t) real * real) >> 33); |
||
| 78 | acc1 = (q31_t) (((q63_t) imag * imag) >> 33); |
||
| 79 | /* store the result in 3.29 format in the destination buffer. */ |
||
| 80 | *pDst++ = acc0 + acc1; |
||
| 81 | |||
| 82 | real = *pSrc++; |
||
| 83 | imag = *pSrc++; |
||
| 84 | acc0 = (q31_t) (((q63_t) real * real) >> 33); |
||
| 85 | acc1 = (q31_t) (((q63_t) imag * imag) >> 33); |
||
| 86 | /* store the result in 3.29 format in the destination buffer. */ |
||
| 87 | *pDst++ = acc0 + acc1; |
||
| 88 | |||
| 89 | real = *pSrc++; |
||
| 90 | imag = *pSrc++; |
||
| 91 | acc0 = (q31_t) (((q63_t) real * real) >> 33); |
||
| 92 | acc1 = (q31_t) (((q63_t) imag * imag) >> 33); |
||
| 93 | /* store the result in 3.29 format in the destination buffer. */ |
||
| 94 | *pDst++ = acc0 + acc1; |
||
| 95 | |||
| 96 | real = *pSrc++; |
||
| 97 | imag = *pSrc++; |
||
| 98 | acc0 = (q31_t) (((q63_t) real * real) >> 33); |
||
| 99 | acc1 = (q31_t) (((q63_t) imag * imag) >> 33); |
||
| 100 | /* store the result in 3.29 format in the destination buffer. */ |
||
| 101 | *pDst++ = acc0 + acc1; |
||
| 102 | |||
| 103 | /* Decrement the loop counter */ |
||
| 104 | blkCnt--; |
||
| 105 | } |
||
| 106 | |||
| 107 | /* If the numSamples is not a multiple of 4, compute any remaining output samples here. |
||
| 108 | ** No loop unrolling is used. */ |
||
| 109 | blkCnt = numSamples % 0x4U; |
||
| 110 | |||
| 111 | while (blkCnt > 0U) |
||
| 112 | { |
||
| 113 | /* C[0] = (A[0] * A[0] + A[1] * A[1]) */ |
||
| 114 | real = *pSrc++; |
||
| 115 | imag = *pSrc++; |
||
| 116 | acc0 = (q31_t) (((q63_t) real * real) >> 33); |
||
| 117 | acc1 = (q31_t) (((q63_t) imag * imag) >> 33); |
||
| 118 | /* store the result in 3.29 format in the destination buffer. */ |
||
| 119 | *pDst++ = acc0 + acc1; |
||
| 120 | |||
| 121 | /* Decrement the loop counter */ |
||
| 122 | blkCnt--; |
||
| 123 | } |
||
| 124 | |||
| 125 | #else |
||
| 126 | |||
| 127 | /* Run the below code for Cortex-M0 */ |
||
| 128 | |||
| 129 | while (numSamples > 0U) |
||
| 130 | { |
||
| 131 | /* out = ((real * real) + (imag * imag)) */ |
||
| 132 | real = *pSrc++; |
||
| 133 | imag = *pSrc++; |
||
| 134 | acc0 = (q31_t) (((q63_t) real * real) >> 33); |
||
| 135 | acc1 = (q31_t) (((q63_t) imag * imag) >> 33); |
||
| 136 | /* store the result in 3.29 format in the destination buffer. */ |
||
| 137 | *pDst++ = acc0 + acc1; |
||
| 138 | |||
| 139 | /* Decrement the loop counter */ |
||
| 140 | numSamples--; |
||
| 141 | } |
||
| 142 | |||
| 143 | #endif /* #if defined (ARM_MATH_DSP) */ |
||
| 144 | |||
| 145 | } |
||
| 146 | |||
| 147 | /** |
||
| 148 | * @} end of cmplx_mag_squared group |
||
| 149 | */ |