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/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_abs_f32.c
* Description: Floating-point vector absolute value
*
* $Date: 27. January 2017
* $Revision: V.1.5.1
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2017 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 "arm_math.h"
#include <math.h>
/**
* @ingroup groupMath
*/
/**
* @defgroup BasicAbs Vector Absolute Value
*
* Computes the absolute value of a vector on an element-by-element basis.
*
* <pre>
* pDst[n] = abs(pSrc[n]), 0 <= n < blockSize.
* </pre>
*
* The functions support in-place computation allowing the source and
* destination pointers to reference the same memory buffer.
* There are separate functions for floating-point, Q7, Q15, and Q31 data types.
*/
/**
* @addtogroup BasicAbs
* @{
*/
/**
* @brief Floating-point vector absolute value.
* @param[in] *pSrc points to the input buffer
* @param[out] *pDst points to the output buffer
* @param[in] blockSize number of samples in each vector
* @return none.
*/
void arm_abs_f32(
float32_t * pSrc,
float32_t * pDst,
uint32_t blockSize)
{
uint32_t blkCnt; /* loop counter */
#if defined (ARM_MATH_DSP)
/* Run the below code for Cortex-M4 and Cortex-M3 */
float32_t in1, in2, in3, in4; /* temporary variables */
/*loop Unrolling */
blkCnt = blockSize >> 2U;
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
** a second loop below computes the remaining 1 to 3 samples. */
while (blkCnt > 0U)
{
/* C = |A| */
/* Calculate absolute and then store the results in the destination buffer. */
/* read sample from source */
in1 = *pSrc;
in2 = *(pSrc + 1);
in3 = *(pSrc + 2);
/* find absolute value */
in1 = fabsf(in1);
/* read sample from source */
in4 = *(pSrc + 3);
/* find absolute value */
in2 = fabsf(in2);
/* read sample from source */
*pDst = in1;
/* find absolute value */
in3 = fabsf(in3);
/* find absolute value */
in4 = fabsf(in4);
/* store result to destination */
*(pDst + 1) = in2;
/* store result to destination */
*(pDst + 2) = in3;
/* store result to destination */
*(pDst + 3) = in4;
/* Update source pointer to process next sampels */
pSrc += 4U;
/* Update destination pointer to process next sampels */
pDst += 4U;
/* Decrement the loop counter */
blkCnt--;
}
/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
** No loop unrolling is used. */
blkCnt = blockSize % 0x4U;
#else
/* Run the below code for Cortex-M0 */
/* Initialize blkCnt with number of samples */
blkCnt = blockSize;
#endif /* #if defined (ARM_MATH_DSP) */
while (blkCnt > 0U)
{
/* C = |A| */
/* Calculate absolute and then store the results in the destination buffer. */
*pDst++ = fabsf(*pSrc++);
/* Decrement the loop counter */
blkCnt--;
}
}
/**
* @} end of BasicAbs group
*/
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