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/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_rms_f16.c
* Description: Root mean square value of the elements of a floating-point vector
*
* $Date: 23 April 2021
* $Revision: V1.9.0
*
* Target Processor: Cortex-M and Cortex-A cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "dsp/statistics_functions_f16.h"
#if defined(ARM_FLOAT16_SUPPORTED)
/**
@ingroup groupStats
*/
/**
@defgroup RMS Root mean square (RMS)
Calculates the Root Mean Square of the elements in the input vector.
The underlying algorithm is used:
<pre>
Result = sqrt(((pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize-1] * pSrc[blockSize-1]) / blockSize));
</pre>
There are separate functions for floating point, Q31, and Q15 data types.
*/
/**
@addtogroup RMS
@{
*/
/**
@brief Root Mean Square of the elements of a floating-point vector.
@param[in] pSrc points to the input vector
@param[in] blockSize number of samples in input vector
@param[out] pResult root mean square value returned here
@return none
*/
#if defined(ARM_MATH_MVE_FLOAT16) && !defined(ARM_MATH_AUTOVECTORIZE)
void arm_rms_f16(
const float16_t * pSrc,
uint32_t blockSize,
float16_t * pResult)
{
float16_t pow = 0.0f;
arm_power_f16(pSrc, blockSize, &pow);
/* Compute Rms and store the result in the destination */
arm_sqrt_f16((_Float16)pow / (_Float16) blockSize, pResult);
}
#else
void arm_rms_f16(
const float16_t * pSrc,
uint32_t blockSize,
float16_t * pResult)
{
uint32_t blkCnt; /* Loop counter */
_Float16 sum = 0.0f16; /* Temporary result storage */
_Float16 in; /* Temporary variable to store input value */
#if defined (ARM_MATH_LOOPUNROLL) && !defined(ARM_MATH_AUTOVECTORIZE)
/* Loop unrolling: Compute 4 outputs at a time */
blkCnt = blockSize >> 2U;
while (blkCnt > 0U)
{
/* C = A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1] */
in = *pSrc++;
/* Compute sum of squares and store result in a temporary variable, sum. */
sum += in * in;
in = *pSrc++;
sum += in * in;
in = *pSrc++;
sum += in * in;
in = *pSrc++;
sum += in * in;
/* Decrement loop counter */
blkCnt--;
}
/* Loop unrolling: Compute remaining outputs */
blkCnt = blockSize % 0x4U;
#else
/* Initialize blkCnt with number of samples */
blkCnt = blockSize;
#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
while (blkCnt > 0U)
{
/* C = A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1] */
in = *pSrc++;
/* Compute sum of squares and store result in a temporary variable. */
sum += ( in * in);
/* Decrement loop counter */
blkCnt--;
}
/* Compute Rms and store result in destination */
arm_sqrt_f16((_Float16)sum / (_Float16) blockSize, pResult);
}
#endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */
/**
@} end of RMS group
*/
#endif /* #if defined(ARM_FLOAT16_SUPPORTED) */