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CMSIS DSP library

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cmsis_dsp/StatisticsFunctions/arm_rms_f32.c@5:3762170b6d4d, 2015-11-20 (annotated)

Committer:
mbed_official
Date:
Fri Nov 20 08:45:18 2015 +0000
Revision:
5:3762170b6d4d
Parent:
3:7a284390b0ce 
Synchronized with git revision 2eb940b9a73af188d3004a2575fdfbb05febe62b



Full URL: https://github.com/mbedmicro/mbed/commit/2eb940b9a73af188d3004a2575fdfbb05febe62b/



Added option to build rpc library. closes #1426

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
mbed_official 5:3762170b6d4d 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
mbed_official 5:3762170b6d4d 4 * $Date: 19. March 2015
mbed_official 5:3762170b6d4d 5 * $Revision: V.1.4.5
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 2:da51fb522205 8 * Title: arm_rms_f32.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Root mean square value of an array of F32 type
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 * @defgroup RMS Root mean square (RMS)
emilmont 1:fdd22bb7aa52 49 *
emilmont 1:fdd22bb7aa52 50 *
emilmont 1:fdd22bb7aa52 51 * Calculates the Root Mean Sqaure of the elements in the input vector.
emilmont 1:fdd22bb7aa52 52 * The underlying algorithm is used:
emilmont 1:fdd22bb7aa52 53 *
emilmont 1:fdd22bb7aa52 54 * <pre>
emilmont 2:da51fb522205 55 * Result = sqrt(((pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize-1] * pSrc[blockSize-1]) / blockSize));
emilmont 1:fdd22bb7aa52 56 * </pre>
emilmont 1:fdd22bb7aa52 57 *
emilmont 1:fdd22bb7aa52 58 * There are separate functions for floating point, Q31, and Q15 data types.
emilmont 1:fdd22bb7aa52 59 */
emilmont 1:fdd22bb7aa52 60
emilmont 1:fdd22bb7aa52 61 /**
emilmont 1:fdd22bb7aa52 62 * @addtogroup RMS
emilmont 1:fdd22bb7aa52 63 * @{
emilmont 1:fdd22bb7aa52 64 */
emilmont 1:fdd22bb7aa52 65
emilmont 1:fdd22bb7aa52 66
emilmont 1:fdd22bb7aa52 67 /**
emilmont 1:fdd22bb7aa52 68 * @brief Root Mean Square of the elements of a floating-point vector.
emilmont 1:fdd22bb7aa52 69 * @param[in] *pSrc points to the input vector
emilmont 1:fdd22bb7aa52 70 * @param[in] blockSize length of the input vector
emilmont 1:fdd22bb7aa52 71 * @param[out] *pResult rms value returned here
emilmont 1:fdd22bb7aa52 72 * @return none.
emilmont 1:fdd22bb7aa52 73 *
emilmont 1:fdd22bb7aa52 74 */
emilmont 1:fdd22bb7aa52 75
emilmont 1:fdd22bb7aa52 76 void arm_rms_f32(
emilmont 1:fdd22bb7aa52 77 float32_t * pSrc,
emilmont 1:fdd22bb7aa52 78 uint32_t blockSize,
emilmont 1:fdd22bb7aa52 79 float32_t * pResult)
emilmont 1:fdd22bb7aa52 80 {
emilmont 1:fdd22bb7aa52 81 float32_t sum = 0.0f; /* Accumulator */
emilmont 1:fdd22bb7aa52 82 float32_t in; /* Tempoprary variable to store input value */
emilmont 1:fdd22bb7aa52 83 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 84
mbed_official 3:7a284390b0ce 85 #ifndef ARM_MATH_CM0_FAMILY
emilmont 1:fdd22bb7aa52 86
emilmont 1:fdd22bb7aa52 87 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 88
emilmont 1:fdd22bb7aa52 89 /* loop Unrolling */
emilmont 1:fdd22bb7aa52 90 blkCnt = blockSize >> 2u;
emilmont 1:fdd22bb7aa52 91
emilmont 1:fdd22bb7aa52 92 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 93 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 94 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 95 {
emilmont 1:fdd22bb7aa52 96 /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
emilmont 1:fdd22bb7aa52 97 /* Compute sum of the squares and then store the result in a temporary variable, sum */
emilmont 1:fdd22bb7aa52 98 in = *pSrc++;
emilmont 1:fdd22bb7aa52 99 sum += in * in;
emilmont 1:fdd22bb7aa52 100 in = *pSrc++;
emilmont 1:fdd22bb7aa52 101 sum += in * in;
emilmont 1:fdd22bb7aa52 102 in = *pSrc++;
emilmont 1:fdd22bb7aa52 103 sum += in * in;
emilmont 1:fdd22bb7aa52 104 in = *pSrc++;
emilmont 1:fdd22bb7aa52 105 sum += in * in;
emilmont 1:fdd22bb7aa52 106
emilmont 1:fdd22bb7aa52 107 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 108 blkCnt--;
emilmont 1:fdd22bb7aa52 109 }
emilmont 1:fdd22bb7aa52 110
emilmont 1:fdd22bb7aa52 111 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 112 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 113 blkCnt = blockSize % 0x4u;
emilmont 1:fdd22bb7aa52 114
emilmont 1:fdd22bb7aa52 115 #else
emilmont 1:fdd22bb7aa52 116
emilmont 1:fdd22bb7aa52 117 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 118
emilmont 1:fdd22bb7aa52 119 /* Loop over blockSize number of values */
emilmont 1:fdd22bb7aa52 120 blkCnt = blockSize;
emilmont 1:fdd22bb7aa52 121
mbed_official 3:7a284390b0ce 122 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emilmont 1:fdd22bb7aa52 123
emilmont 1:fdd22bb7aa52 124 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 125 {
emilmont 1:fdd22bb7aa52 126 /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
emilmont 1:fdd22bb7aa52 127 /* Compute sum of the squares and then store the results in a temporary variable, sum */
emilmont 1:fdd22bb7aa52 128 in = *pSrc++;
emilmont 1:fdd22bb7aa52 129 sum += in * in;
emilmont 1:fdd22bb7aa52 130
emilmont 1:fdd22bb7aa52 131 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 132 blkCnt--;
emilmont 1:fdd22bb7aa52 133 }
emilmont 1:fdd22bb7aa52 134
emilmont 1:fdd22bb7aa52 135 /* Compute Rms and store the result in the destination */
emilmont 1:fdd22bb7aa52 136 arm_sqrt_f32(sum / (float32_t) blockSize, pResult);
emilmont 1:fdd22bb7aa52 137 }
emilmont 1:fdd22bb7aa52 138
emilmont 1:fdd22bb7aa52 139 /**
emilmont 1:fdd22bb7aa52 140 * @} end of RMS group
emilmont 1:fdd22bb7aa52 141 */