Laxmi Kant Tiwari / mbed-dsp

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of mbed-dsp by mbed official

cmsis_dsp/BasicMathFunctions/arm_abs_q15.c@2:da51fb522205, 2013-05-30 (annotated)

Committer:
emilmont
Date:
Thu May 30 17:10:11 2013 +0100
Revision:
2:da51fb522205
Parent:
1:fdd22bb7aa52
Child:
3:7a284390b0ce
Keep "cmsis-dsp" module in synch with its source

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
emilmont 1:fdd22bb7aa52 2 * Copyright (C) 2010 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
emilmont 1:fdd22bb7aa52 4 * $Date: 15. February 2012
emilmont 2:da51fb522205 5 * $Revision: V1.1.0
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 2:da51fb522205 8 * Title: arm_abs_q15.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Q15 vector absolute value.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
emilmont 1:fdd22bb7aa52 14 * Version 1.1.0 2012/02/15
emilmont 1:fdd22bb7aa52 15 * Updated with more optimizations, bug fixes and minor API changes.
emilmont 1:fdd22bb7aa52 16 *
emilmont 1:fdd22bb7aa52 17 * Version 1.0.10 2011/7/15
emilmont 1:fdd22bb7aa52 18 * Big Endian support added and Merged M0 and M3/M4 Source code.
emilmont 1:fdd22bb7aa52 19 *
emilmont 1:fdd22bb7aa52 20 * Version 1.0.3 2010/11/29
emilmont 1:fdd22bb7aa52 21 * Re-organized the CMSIS folders and updated documentation.
emilmont 1:fdd22bb7aa52 22 *
emilmont 1:fdd22bb7aa52 23 * Version 1.0.2 2010/11/11
emilmont 1:fdd22bb7aa52 24 * Documentation updated.
emilmont 1:fdd22bb7aa52 25 *
emilmont 1:fdd22bb7aa52 26 * Version 1.0.1 2010/10/05
emilmont 1:fdd22bb7aa52 27 * Production release and review comments incorporated.
emilmont 1:fdd22bb7aa52 28 *
emilmont 1:fdd22bb7aa52 29 * Version 1.0.0 2010/09/20
emilmont 1:fdd22bb7aa52 30 * Production release and review comments incorporated.
emilmont 1:fdd22bb7aa52 31 *
emilmont 1:fdd22bb7aa52 32 * Version 0.0.7 2010/06/10
emilmont 1:fdd22bb7aa52 33 * Misra-C changes done
emilmont 1:fdd22bb7aa52 34 * -------------------------------------------------------------------- */
emilmont 1:fdd22bb7aa52 35
emilmont 1:fdd22bb7aa52 36 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 37
emilmont 1:fdd22bb7aa52 38 /**
emilmont 1:fdd22bb7aa52 39 * @ingroup groupMath
emilmont 1:fdd22bb7aa52 40 */
emilmont 1:fdd22bb7aa52 41
emilmont 1:fdd22bb7aa52 42 /**
emilmont 1:fdd22bb7aa52 43 * @addtogroup BasicAbs
emilmont 1:fdd22bb7aa52 44 * @{
emilmont 1:fdd22bb7aa52 45 */
emilmont 1:fdd22bb7aa52 46
emilmont 1:fdd22bb7aa52 47 /**
emilmont 1:fdd22bb7aa52 48 * @brief Q15 vector absolute value.
emilmont 1:fdd22bb7aa52 49 * @param[in] *pSrc points to the input buffer
emilmont 1:fdd22bb7aa52 50 * @param[out] *pDst points to the output buffer
emilmont 1:fdd22bb7aa52 51 * @param[in] blockSize number of samples in each vector
emilmont 1:fdd22bb7aa52 52 * @return none.
emilmont 1:fdd22bb7aa52 53 *
emilmont 1:fdd22bb7aa52 54 * <b>Scaling and Overflow Behavior:</b>
emilmont 1:fdd22bb7aa52 55 * \par
emilmont 1:fdd22bb7aa52 56 * The function uses saturating arithmetic.
emilmont 1:fdd22bb7aa52 57 * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
emilmont 1:fdd22bb7aa52 58 */
emilmont 1:fdd22bb7aa52 59
emilmont 1:fdd22bb7aa52 60 void arm_abs_q15(
emilmont 1:fdd22bb7aa52 61 q15_t * pSrc,
emilmont 1:fdd22bb7aa52 62 q15_t * pDst,
emilmont 1:fdd22bb7aa52 63 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 64 {
emilmont 1:fdd22bb7aa52 65 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 66
emilmont 1:fdd22bb7aa52 67 #ifndef ARM_MATH_CM0
emilmont 1:fdd22bb7aa52 68
emilmont 1:fdd22bb7aa52 69 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 70
emilmont 1:fdd22bb7aa52 71 q15_t in1; /* Input value1 */
emilmont 1:fdd22bb7aa52 72 q15_t in2; /* Input value2 */
emilmont 1:fdd22bb7aa52 73
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 76 blkCnt = blockSize >> 2u;
emilmont 1:fdd22bb7aa52 77
emilmont 1:fdd22bb7aa52 78 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 79 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 80 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 81 {
emilmont 1:fdd22bb7aa52 82 /* C = |A| */
emilmont 1:fdd22bb7aa52 83 /* Read two inputs */
emilmont 1:fdd22bb7aa52 84 in1 = *pSrc++;
emilmont 1:fdd22bb7aa52 85 in2 = *pSrc++;
emilmont 1:fdd22bb7aa52 86
emilmont 1:fdd22bb7aa52 87
emilmont 1:fdd22bb7aa52 88 /* Store the Absolute result in the destination buffer by packing the two values, in a single cycle */
emilmont 1:fdd22bb7aa52 89
emilmont 1:fdd22bb7aa52 90 #ifndef ARM_MATH_BIG_ENDIAN
emilmont 1:fdd22bb7aa52 91
emilmont 1:fdd22bb7aa52 92 *__SIMD32(pDst)++ =
emilmont 1:fdd22bb7aa52 93 __PKHBT(((in1 > 0) ? in1 : __QSUB16(0, in1)),
emilmont 1:fdd22bb7aa52 94 ((in2 > 0) ? in2 : __QSUB16(0, in2)), 16);
emilmont 1:fdd22bb7aa52 95
emilmont 1:fdd22bb7aa52 96 #else
emilmont 1:fdd22bb7aa52 97
emilmont 1:fdd22bb7aa52 98
emilmont 1:fdd22bb7aa52 99 *__SIMD32(pDst)++ =
emilmont 1:fdd22bb7aa52 100 __PKHBT(((in2 > 0) ? in2 : __QSUB16(0, in2)),
emilmont 1:fdd22bb7aa52 101 ((in1 > 0) ? in1 : __QSUB16(0, in1)), 16);
emilmont 1:fdd22bb7aa52 102
emilmont 1:fdd22bb7aa52 103 #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
emilmont 1:fdd22bb7aa52 104
emilmont 1:fdd22bb7aa52 105 in1 = *pSrc++;
emilmont 1:fdd22bb7aa52 106 in2 = *pSrc++;
emilmont 1:fdd22bb7aa52 107
emilmont 1:fdd22bb7aa52 108
emilmont 1:fdd22bb7aa52 109 #ifndef ARM_MATH_BIG_ENDIAN
emilmont 1:fdd22bb7aa52 110
emilmont 1:fdd22bb7aa52 111 *__SIMD32(pDst)++ =
emilmont 1:fdd22bb7aa52 112 __PKHBT(((in1 > 0) ? in1 : __QSUB16(0, in1)),
emilmont 1:fdd22bb7aa52 113 ((in2 > 0) ? in2 : __QSUB16(0, in2)), 16);
emilmont 1:fdd22bb7aa52 114
emilmont 1:fdd22bb7aa52 115 #else
emilmont 1:fdd22bb7aa52 116
emilmont 1:fdd22bb7aa52 117
emilmont 1:fdd22bb7aa52 118 *__SIMD32(pDst)++ =
emilmont 1:fdd22bb7aa52 119 __PKHBT(((in2 > 0) ? in2 : __QSUB16(0, in2)),
emilmont 1:fdd22bb7aa52 120 ((in1 > 0) ? in1 : __QSUB16(0, in1)), 16);
emilmont 1:fdd22bb7aa52 121
emilmont 1:fdd22bb7aa52 122 #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
emilmont 1:fdd22bb7aa52 123
emilmont 1:fdd22bb7aa52 124 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 125 blkCnt--;
emilmont 1:fdd22bb7aa52 126 }
emilmont 1:fdd22bb7aa52 127
emilmont 1:fdd22bb7aa52 128 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 129 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 130 blkCnt = blockSize % 0x4u;
emilmont 1:fdd22bb7aa52 131
emilmont 1:fdd22bb7aa52 132 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 133 {
emilmont 1:fdd22bb7aa52 134 /* C = |A| */
emilmont 1:fdd22bb7aa52 135 /* Read the input */
emilmont 1:fdd22bb7aa52 136 in1 = *pSrc++;
emilmont 1:fdd22bb7aa52 137
emilmont 1:fdd22bb7aa52 138 /* Calculate absolute value of input and then store the result in the destination buffer. */
emilmont 1:fdd22bb7aa52 139 *pDst++ = (in1 > 0) ? in1 : __QSUB16(0, in1);
emilmont 1:fdd22bb7aa52 140
emilmont 1:fdd22bb7aa52 141 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 142 blkCnt--;
emilmont 1:fdd22bb7aa52 143 }
emilmont 1:fdd22bb7aa52 144
emilmont 1:fdd22bb7aa52 145 #else
emilmont 1:fdd22bb7aa52 146
emilmont 1:fdd22bb7aa52 147 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 148
emilmont 1:fdd22bb7aa52 149 q15_t in; /* Temporary input variable */
emilmont 1:fdd22bb7aa52 150
emilmont 1:fdd22bb7aa52 151 /* Initialize blkCnt with number of samples */
emilmont 1:fdd22bb7aa52 152 blkCnt = blockSize;
emilmont 1:fdd22bb7aa52 153
emilmont 1:fdd22bb7aa52 154 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 155 {
emilmont 1:fdd22bb7aa52 156 /* C = |A| */
emilmont 1:fdd22bb7aa52 157 /* Read the input */
emilmont 1:fdd22bb7aa52 158 in = *pSrc++;
emilmont 1:fdd22bb7aa52 159
emilmont 1:fdd22bb7aa52 160 /* Calculate absolute value of input and then store the result in the destination buffer. */
emilmont 1:fdd22bb7aa52 161 *pDst++ = (in > 0) ? in : ((in == (q15_t) 0x8000) ? 0x7fff : -in);
emilmont 1:fdd22bb7aa52 162
emilmont 1:fdd22bb7aa52 163 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 164 blkCnt--;
emilmont 1:fdd22bb7aa52 165 }
emilmont 1:fdd22bb7aa52 166
emilmont 1:fdd22bb7aa52 167 #endif /* #ifndef ARM_MATH_CM0 */
emilmont 1:fdd22bb7aa52 168
emilmont 1:fdd22bb7aa52 169 }
emilmont 1:fdd22bb7aa52 170
emilmont 1:fdd22bb7aa52 171 /**
emilmont 1:fdd22bb7aa52 172 * @} end of BasicAbs group
emilmont 1:fdd22bb7aa52 173 */