Laxmi Kant Tiwari / mbed-dsp

CMSIS DSP Lib

Fork of mbed-dsp by mbed official

cmsis_dsp/BasicMathFunctions/arm_abs_f32.c@3:7a284390b0ce, 2013-11-08 (annotated)

Committer:
mbed_official
Date:
Fri Nov 08 13:45:10 2013 +0000
Revision:
3:7a284390b0ce
Parent:
2:da51fb522205 
Synchronized with git revision e69956aba2f68a2a26ac26b051f8d349deaa1ce8

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_abs_f32.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Vector absolute value.
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 #include <math.h>
emilmont 1:fdd22bb7aa52 43
emilmont 1:fdd22bb7aa52 44 /**
emilmont 1:fdd22bb7aa52 45 * @ingroup groupMath
emilmont 1:fdd22bb7aa52 46 */
emilmont 1:fdd22bb7aa52 47
emilmont 1:fdd22bb7aa52 48 /**
emilmont 1:fdd22bb7aa52 49 * @defgroup BasicAbs Vector Absolute Value
emilmont 1:fdd22bb7aa52 50 *
emilmont 1:fdd22bb7aa52 51 * Computes the absolute value of a vector on an element-by-element basis.
emilmont 1:fdd22bb7aa52 52 *
emilmont 1:fdd22bb7aa52 53 * <pre>
mbed_official 3:7a284390b0ce 54 * pDst[n] = abs(pSrc[n]), 0 <= n < blockSize.
emilmont 1:fdd22bb7aa52 55 * </pre>
emilmont 1:fdd22bb7aa52 56 *
mbed_official 3:7a284390b0ce 57 * The functions support in-place computation allowing the source and
mbed_official 3:7a284390b0ce 58 * destination pointers to reference the same memory buffer.
mbed_official 3:7a284390b0ce 59 * There are separate functions for floating-point, Q7, Q15, and Q31 data types.
emilmont 1:fdd22bb7aa52 60 */
emilmont 1:fdd22bb7aa52 61
emilmont 1:fdd22bb7aa52 62 /**
emilmont 1:fdd22bb7aa52 63 * @addtogroup BasicAbs
emilmont 1:fdd22bb7aa52 64 * @{
emilmont 1:fdd22bb7aa52 65 */
emilmont 1:fdd22bb7aa52 66
emilmont 1:fdd22bb7aa52 67 /**
emilmont 1:fdd22bb7aa52 68 * @brief Floating-point vector absolute value.
emilmont 1:fdd22bb7aa52 69 * @param[in] *pSrc points to the input buffer
emilmont 1:fdd22bb7aa52 70 * @param[out] *pDst points to the output buffer
emilmont 1:fdd22bb7aa52 71 * @param[in] blockSize number of samples in each vector
emilmont 1:fdd22bb7aa52 72 * @return none.
emilmont 1:fdd22bb7aa52 73 */
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 void arm_abs_f32(
emilmont 1:fdd22bb7aa52 76 float32_t * pSrc,
emilmont 1:fdd22bb7aa52 77 float32_t * pDst,
emilmont 1:fdd22bb7aa52 78 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 79 {
emilmont 1:fdd22bb7aa52 80 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 81
mbed_official 3:7a284390b0ce 82 #ifndef ARM_MATH_CM0_FAMILY
emilmont 1:fdd22bb7aa52 83
emilmont 1:fdd22bb7aa52 84 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 85 float32_t in1, in2, in3, in4; /* temporary variables */
emilmont 1:fdd22bb7aa52 86
emilmont 1:fdd22bb7aa52 87 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 88 blkCnt = blockSize >> 2u;
emilmont 1:fdd22bb7aa52 89
emilmont 1:fdd22bb7aa52 90 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 91 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 92 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 93 {
emilmont 1:fdd22bb7aa52 94 /* C = |A| */
emilmont 1:fdd22bb7aa52 95 /* Calculate absolute and then store the results in the destination buffer. */
emilmont 1:fdd22bb7aa52 96 /* read sample from source */
emilmont 1:fdd22bb7aa52 97 in1 = *pSrc;
emilmont 1:fdd22bb7aa52 98 in2 = *(pSrc + 1);
emilmont 1:fdd22bb7aa52 99 in3 = *(pSrc + 2);
emilmont 1:fdd22bb7aa52 100
emilmont 1:fdd22bb7aa52 101 /* find absolute value */
emilmont 1:fdd22bb7aa52 102 in1 = fabsf(in1);
emilmont 1:fdd22bb7aa52 103
emilmont 1:fdd22bb7aa52 104 /* read sample from source */
emilmont 1:fdd22bb7aa52 105 in4 = *(pSrc + 3);
emilmont 1:fdd22bb7aa52 106
emilmont 1:fdd22bb7aa52 107 /* find absolute value */
emilmont 1:fdd22bb7aa52 108 in2 = fabsf(in2);
emilmont 1:fdd22bb7aa52 109
emilmont 1:fdd22bb7aa52 110 /* read sample from source */
emilmont 1:fdd22bb7aa52 111 *pDst = in1;
emilmont 1:fdd22bb7aa52 112
emilmont 1:fdd22bb7aa52 113 /* find absolute value */
emilmont 1:fdd22bb7aa52 114 in3 = fabsf(in3);
emilmont 1:fdd22bb7aa52 115
emilmont 1:fdd22bb7aa52 116 /* find absolute value */
emilmont 1:fdd22bb7aa52 117 in4 = fabsf(in4);
emilmont 1:fdd22bb7aa52 118
emilmont 1:fdd22bb7aa52 119 /* store result to destination */
emilmont 1:fdd22bb7aa52 120 *(pDst + 1) = in2;
emilmont 1:fdd22bb7aa52 121
emilmont 1:fdd22bb7aa52 122 /* store result to destination */
emilmont 1:fdd22bb7aa52 123 *(pDst + 2) = in3;
emilmont 1:fdd22bb7aa52 124
emilmont 1:fdd22bb7aa52 125 /* store result to destination */
emilmont 1:fdd22bb7aa52 126 *(pDst + 3) = in4;
emilmont 1:fdd22bb7aa52 127
emilmont 1:fdd22bb7aa52 128
emilmont 1:fdd22bb7aa52 129 /* Update source pointer to process next sampels */
emilmont 1:fdd22bb7aa52 130 pSrc += 4u;
emilmont 1:fdd22bb7aa52 131
emilmont 1:fdd22bb7aa52 132 /* Update destination pointer to process next sampels */
emilmont 1:fdd22bb7aa52 133 pDst += 4u;
emilmont 1:fdd22bb7aa52 134
emilmont 1:fdd22bb7aa52 135 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 136 blkCnt--;
emilmont 1:fdd22bb7aa52 137 }
emilmont 1:fdd22bb7aa52 138
emilmont 1:fdd22bb7aa52 139 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 140 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 141 blkCnt = blockSize % 0x4u;
emilmont 1:fdd22bb7aa52 142
emilmont 1:fdd22bb7aa52 143 #else
emilmont 1:fdd22bb7aa52 144
emilmont 1:fdd22bb7aa52 145 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 146
emilmont 1:fdd22bb7aa52 147 /* Initialize blkCnt with number of samples */
emilmont 1:fdd22bb7aa52 148 blkCnt = blockSize;
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 /* C = |A| */
emilmont 1:fdd22bb7aa52 155 /* Calculate absolute and then store the results in the destination buffer. */
emilmont 1:fdd22bb7aa52 156 *pDst++ = fabsf(*pSrc++);
emilmont 1:fdd22bb7aa52 157
emilmont 1:fdd22bb7aa52 158 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 159 blkCnt--;
emilmont 1:fdd22bb7aa52 160 }
emilmont 1:fdd22bb7aa52 161 }
emilmont 1:fdd22bb7aa52 162
emilmont 1:fdd22bb7aa52 163 /**
emilmont 1:fdd22bb7aa52 164 * @} end of BasicAbs group
emilmont 1:fdd22bb7aa52 165 */