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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_min_q15.c |
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| 4 | * Description: Minimum value of a Q15 vector |
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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 groupStats |
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| 33 | */ |
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| 34 | |||
| 35 | |||
| 36 | /** |
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| 37 | * @addtogroup Min |
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| 38 | * @{ |
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| 39 | */ |
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| 40 | |||
| 41 | |||
| 42 | /** |
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| 43 | * @brief Minimum value of a Q15 vector. |
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| 44 | * @param[in] *pSrc points to the input vector |
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| 45 | * @param[in] blockSize length of the input vector |
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| 46 | * @param[out] *pResult minimum value returned here |
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| 47 | * @param[out] *pIndex index of minimum value returned here |
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| 48 | * @return none. |
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| 49 | */ |
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| 50 | |||
| 51 | void arm_min_q15( |
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| 52 | q15_t * pSrc, |
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| 53 | uint32_t blockSize, |
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| 54 | q15_t * pResult, |
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| 55 | uint32_t * pIndex) |
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| 56 | { |
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| 57 | #if defined (ARM_MATH_DSP) |
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| 58 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
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| 59 | |||
| 60 | q15_t minVal1, minVal2, out; /* Temporary variables to store the output value. */ |
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| 61 | uint32_t blkCnt, outIndex, count; /* loop counter */ |
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| 62 | |||
| 63 | /* Initialise the count value. */ |
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| 64 | count = 0U; |
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| 65 | /* Initialise the index value to zero. */ |
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| 66 | outIndex = 0U; |
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| 67 | /* Load first input value that act as reference value for comparision */ |
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| 68 | out = *pSrc++; |
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| 69 | |||
| 70 | /* Loop unrolling */ |
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| 71 | blkCnt = (blockSize - 1U) >> 2U; |
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| 72 | |||
| 73 | while (blkCnt > 0U) |
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| 74 | { |
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| 75 | /* Initialize minVal to the next consecutive values one by one */ |
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| 76 | minVal1 = *pSrc++; |
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| 77 | minVal2 = *pSrc++; |
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| 78 | |||
| 79 | /* compare for the minimum value */ |
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| 80 | if (out > minVal1) |
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| 81 | { |
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| 82 | /* Update the minimum value and its index */ |
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| 83 | out = minVal1; |
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| 84 | outIndex = count + 1U; |
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| 85 | } |
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| 86 | |||
| 87 | /* compare for the minimum value */ |
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| 88 | if (out > minVal2) |
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| 89 | { |
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| 90 | /* Update the minimum value and its index */ |
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| 91 | out = minVal2; |
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| 92 | outIndex = count + 2U; |
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| 93 | } |
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| 94 | |||
| 95 | /* Initialize minVal to the next consecutive values one by one */ |
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| 96 | minVal1 = *pSrc++; |
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| 97 | minVal2 = *pSrc++; |
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| 98 | |||
| 99 | /* compare for the minimum value */ |
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| 100 | if (out > minVal1) |
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| 101 | { |
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| 102 | /* Update the minimum value and its index */ |
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| 103 | out = minVal1; |
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| 104 | outIndex = count + 3U; |
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| 105 | } |
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| 106 | |||
| 107 | /* compare for the minimum value */ |
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| 108 | if (out > minVal2) |
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| 109 | { |
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| 110 | /* Update the minimum value and its index */ |
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| 111 | out = minVal2; |
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| 112 | outIndex = count + 4U; |
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| 113 | } |
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| 114 | |||
| 115 | count += 4U; |
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| 116 | |||
| 117 | /* Decrement the loop counter */ |
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| 118 | blkCnt--; |
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| 119 | } |
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| 120 | |||
| 121 | /* if (blockSize - 1U) is not multiple of 4 */ |
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| 122 | blkCnt = (blockSize - 1U) % 4U; |
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| 123 | |||
| 124 | #else |
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| 125 | /* Run the below code for Cortex-M0 */ |
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| 126 | |||
| 127 | q15_t minVal1, out; /* Temporary variables to store the output value. */ |
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| 128 | uint32_t blkCnt, outIndex; /* loop counter */ |
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| 129 | |||
| 130 | /* Initialise the index value to zero. */ |
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| 131 | outIndex = 0U; |
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| 132 | /* Load first input value that act as reference value for comparision */ |
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| 133 | out = *pSrc++; |
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| 134 | |||
| 135 | blkCnt = (blockSize - 1U); |
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| 136 | |||
| 137 | #endif /* #if defined (ARM_MATH_DSP) */ |
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| 138 | |||
| 139 | while (blkCnt > 0U) |
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| 140 | { |
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| 141 | /* Initialize minVal to the next consecutive values one by one */ |
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| 142 | minVal1 = *pSrc++; |
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| 143 | |||
| 144 | /* compare for the minimum value */ |
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| 145 | if (out > minVal1) |
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| 146 | { |
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| 147 | /* Update the minimum value and it's index */ |
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| 148 | out = minVal1; |
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| 149 | outIndex = blockSize - blkCnt; |
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| 150 | } |
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| 151 | |||
| 152 | /* Decrement the loop counter */ |
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| 153 | blkCnt--; |
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| 154 | } |
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| 155 | |||
| 156 | /* Store the minimum value and it's index into destination pointers */ |
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| 157 | *pResult = out; |
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| 158 | *pIndex = outIndex; |
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| 159 | } |
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| 160 | |||
| 161 | /** |
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| 162 | * @} end of Min group |
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| 163 | */ |