Laxmi Kant Tiwari / mbed-dsp

CMSIS DSP Lib

Fork of mbed-dsp by mbed official

cmsis_dsp/StatisticsFunctions/arm_max_q31.c@4:9cee975aadce, 2014-06-23 (annotated)

Committer:
mbed_official
Date:
Mon Jun 23 09:30:09 2014 +0100
Revision:
4:9cee975aadce
Parent:
3:7a284390b0ce 
Synchronized with git revision 6e7c7bcec41226f536474daae3c13d49e4c0e865



Full URL: https://github.com/mbedmicro/mbed/commit/6e7c7bcec41226f536474daae3c13d49e4c0e865/



Fix signed unsigned compare in dsp library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
mbed_official 3:7a284390b0ce 2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
mbed_official 3:7a284390b0ce 4 * $Date: 17. January 2013
mbed_official 3:7a284390b0ce 5 * $Revision: V1.4.1
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 2:da51fb522205 8 * Title: arm_max_q31.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Maximum value of a Q31 vector.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
mbed_official 3:7a284390b0ce 14 * Redistribution and use in source and binary forms, with or without
mbed_official 3:7a284390b0ce 15 * modification, are permitted provided that the following conditions
mbed_official 3:7a284390b0ce 16 * are met:
mbed_official 3:7a284390b0ce 17 * - Redistributions of source code must retain the above copyright
mbed_official 3:7a284390b0ce 18 * notice, this list of conditions and the following disclaimer.
mbed_official 3:7a284390b0ce 19 * - Redistributions in binary form must reproduce the above copyright
mbed_official 3:7a284390b0ce 20 * notice, this list of conditions and the following disclaimer in
mbed_official 3:7a284390b0ce 21 * the documentation and/or other materials provided with the
mbed_official 3:7a284390b0ce 22 * distribution.
mbed_official 3:7a284390b0ce 23 * - Neither the name of ARM LIMITED nor the names of its contributors
mbed_official 3:7a284390b0ce 24 * may be used to endorse or promote products derived from this
mbed_official 3:7a284390b0ce 25 * software without specific prior written permission.
mbed_official 3:7a284390b0ce 26 *
mbed_official 3:7a284390b0ce 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
mbed_official 3:7a284390b0ce 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
mbed_official 3:7a284390b0ce 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
mbed_official 3:7a284390b0ce 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
mbed_official 3:7a284390b0ce 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
mbed_official 3:7a284390b0ce 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
mbed_official 3:7a284390b0ce 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
mbed_official 3:7a284390b0ce 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 3:7a284390b0ce 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
mbed_official 3:7a284390b0ce 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
mbed_official 3:7a284390b0ce 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
mbed_official 3:7a284390b0ce 38 * POSSIBILITY OF SUCH DAMAGE.
emilmont 1:fdd22bb7aa52 39 * ---------------------------------------------------------------------------- */
emilmont 1:fdd22bb7aa52 40
emilmont 1:fdd22bb7aa52 41 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 42
emilmont 1:fdd22bb7aa52 43 /**
emilmont 1:fdd22bb7aa52 44 * @ingroup groupStats
emilmont 1:fdd22bb7aa52 45 */
emilmont 1:fdd22bb7aa52 46
emilmont 1:fdd22bb7aa52 47 /**
emilmont 1:fdd22bb7aa52 48 * @addtogroup Max
emilmont 1:fdd22bb7aa52 49 * @{
emilmont 1:fdd22bb7aa52 50 */
emilmont 1:fdd22bb7aa52 51
emilmont 1:fdd22bb7aa52 52
emilmont 1:fdd22bb7aa52 53 /**
emilmont 1:fdd22bb7aa52 54 * @brief Maximum value of a Q31 vector.
emilmont 1:fdd22bb7aa52 55 * @param[in] *pSrc points to the input vector
emilmont 1:fdd22bb7aa52 56 * @param[in] blockSize length of the input vector
emilmont 1:fdd22bb7aa52 57 * @param[out] *pResult maximum value returned here
emilmont 1:fdd22bb7aa52 58 * @param[out] *pIndex index of maximum value returned here
emilmont 1:fdd22bb7aa52 59 * @return none.
emilmont 1:fdd22bb7aa52 60 */
emilmont 1:fdd22bb7aa52 61
emilmont 1:fdd22bb7aa52 62 void arm_max_q31(
emilmont 1:fdd22bb7aa52 63 q31_t * pSrc,
emilmont 1:fdd22bb7aa52 64 uint32_t blockSize,
emilmont 1:fdd22bb7aa52 65 q31_t * pResult,
emilmont 1:fdd22bb7aa52 66 uint32_t * pIndex)
emilmont 1:fdd22bb7aa52 67 {
mbed_official 3:7a284390b0ce 68 #ifndef ARM_MATH_CM0_FAMILY
emilmont 1:fdd22bb7aa52 69
emilmont 1:fdd22bb7aa52 70 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 71 q31_t maxVal1, maxVal2, out; /* Temporary variables to store the output value. */
emilmont 1:fdd22bb7aa52 72 uint32_t blkCnt, outIndex, count; /* loop counter */
emilmont 1:fdd22bb7aa52 73
emilmont 1:fdd22bb7aa52 74 /* Initialise the count value. */
emilmont 1:fdd22bb7aa52 75 count = 0u;
emilmont 1:fdd22bb7aa52 76 /* Initialise the index value to zero. */
emilmont 1:fdd22bb7aa52 77 outIndex = 0u;
emilmont 1:fdd22bb7aa52 78 /* Load first input value that act as reference value for comparision */
emilmont 1:fdd22bb7aa52 79 out = *pSrc++;
emilmont 1:fdd22bb7aa52 80
emilmont 1:fdd22bb7aa52 81 /* Loop unrolling */
emilmont 1:fdd22bb7aa52 82 blkCnt = (blockSize - 1u) >> 2u;
emilmont 1:fdd22bb7aa52 83
emilmont 1:fdd22bb7aa52 84 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 85 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 86 {
emilmont 1:fdd22bb7aa52 87 /* Initialize maxVal to the next consecutive values one by one */
emilmont 1:fdd22bb7aa52 88 maxVal1 = *pSrc++;
emilmont 1:fdd22bb7aa52 89
emilmont 1:fdd22bb7aa52 90 maxVal2 = *pSrc++;
emilmont 1:fdd22bb7aa52 91
emilmont 1:fdd22bb7aa52 92 /* compare for the maximum value */
emilmont 1:fdd22bb7aa52 93 if(out < maxVal1)
emilmont 1:fdd22bb7aa52 94 {
emilmont 1:fdd22bb7aa52 95 /* Update the maximum value and its index */
emilmont 1:fdd22bb7aa52 96 out = maxVal1;
emilmont 1:fdd22bb7aa52 97 outIndex = count + 1u;
emilmont 1:fdd22bb7aa52 98 }
emilmont 1:fdd22bb7aa52 99
emilmont 1:fdd22bb7aa52 100 maxVal1 = *pSrc++;
emilmont 1:fdd22bb7aa52 101
emilmont 1:fdd22bb7aa52 102 /* compare for the maximum value */
emilmont 1:fdd22bb7aa52 103 if(out < maxVal2)
emilmont 1:fdd22bb7aa52 104 {
emilmont 1:fdd22bb7aa52 105 /* Update the maximum value and its index */
emilmont 1:fdd22bb7aa52 106 out = maxVal2;
emilmont 1:fdd22bb7aa52 107 outIndex = count + 2u;
emilmont 1:fdd22bb7aa52 108 }
emilmont 1:fdd22bb7aa52 109
emilmont 1:fdd22bb7aa52 110 maxVal2 = *pSrc++;
emilmont 1:fdd22bb7aa52 111
emilmont 1:fdd22bb7aa52 112 /* compare for the maximum value */
emilmont 1:fdd22bb7aa52 113 if(out < maxVal1)
emilmont 1:fdd22bb7aa52 114 {
emilmont 1:fdd22bb7aa52 115 /* Update the maximum value and its index */
emilmont 1:fdd22bb7aa52 116 out = maxVal1;
emilmont 1:fdd22bb7aa52 117 outIndex = count + 3u;
emilmont 1:fdd22bb7aa52 118 }
emilmont 1:fdd22bb7aa52 119
emilmont 1:fdd22bb7aa52 120 /* compare for the maximum value */
emilmont 1:fdd22bb7aa52 121 if(out < maxVal2)
emilmont 1:fdd22bb7aa52 122 {
emilmont 1:fdd22bb7aa52 123 /* Update the maximum value and its index */
emilmont 1:fdd22bb7aa52 124 out = maxVal2;
emilmont 1:fdd22bb7aa52 125 outIndex = count + 4u;
emilmont 1:fdd22bb7aa52 126 }
emilmont 1:fdd22bb7aa52 127
emilmont 1:fdd22bb7aa52 128 count += 4u;
emilmont 1:fdd22bb7aa52 129
emilmont 1:fdd22bb7aa52 130 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 131 blkCnt--;
emilmont 1:fdd22bb7aa52 132 }
emilmont 1:fdd22bb7aa52 133
emilmont 1:fdd22bb7aa52 134 /* if (blockSize - 1u) is not multiple of 4 */
emilmont 1:fdd22bb7aa52 135 blkCnt = (blockSize - 1u) % 4u;
emilmont 1:fdd22bb7aa52 136
emilmont 1:fdd22bb7aa52 137 #else
emilmont 1:fdd22bb7aa52 138
emilmont 1:fdd22bb7aa52 139 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 140 q31_t maxVal1, out; /* Temporary variables to store the output value. */
emilmont 1:fdd22bb7aa52 141 uint32_t blkCnt, outIndex; /* loop counter */
emilmont 1:fdd22bb7aa52 142
emilmont 1:fdd22bb7aa52 143 /* Initialise the index value to zero. */
emilmont 1:fdd22bb7aa52 144 outIndex = 0u;
emilmont 1:fdd22bb7aa52 145 /* Load first input value that act as reference value for comparision */
emilmont 1:fdd22bb7aa52 146 out = *pSrc++;
emilmont 1:fdd22bb7aa52 147
emilmont 1:fdd22bb7aa52 148 blkCnt = (blockSize - 1u);
emilmont 1:fdd22bb7aa52 149
mbed_official 3:7a284390b0ce 150 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emilmont 1:fdd22bb7aa52 151
emilmont 1:fdd22bb7aa52 152 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 153 {
emilmont 1:fdd22bb7aa52 154 /* Initialize maxVal to the next consecutive values one by one */
emilmont 1:fdd22bb7aa52 155 maxVal1 = *pSrc++;
emilmont 1:fdd22bb7aa52 156
emilmont 1:fdd22bb7aa52 157 /* compare for the maximum value */
emilmont 1:fdd22bb7aa52 158 if(out < maxVal1)
emilmont 1:fdd22bb7aa52 159 {
emilmont 1:fdd22bb7aa52 160 /* Update the maximum value and it's index */
emilmont 1:fdd22bb7aa52 161 out = maxVal1;
emilmont 1:fdd22bb7aa52 162 outIndex = blockSize - blkCnt;
emilmont 1:fdd22bb7aa52 163 }
emilmont 1:fdd22bb7aa52 164
emilmont 1:fdd22bb7aa52 165 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 166 blkCnt--;
emilmont 1:fdd22bb7aa52 167
emilmont 1:fdd22bb7aa52 168 }
emilmont 1:fdd22bb7aa52 169
emilmont 1:fdd22bb7aa52 170 /* Store the maximum value and its index into destination pointers */
emilmont 1:fdd22bb7aa52 171 *pResult = out;
emilmont 1:fdd22bb7aa52 172 *pIndex = outIndex;
emilmont 1:fdd22bb7aa52 173 }
emilmont 1:fdd22bb7aa52 174
emilmont 1:fdd22bb7aa52 175 /**
emilmont 1:fdd22bb7aa52 176 * @} end of Max group
emilmont 1:fdd22bb7aa52 177 */