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/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 15. February 2012
* $Revision: V1.1.0
*
* Project: CMSIS DSP Library
* Title: arm_max_f32.c
*
* Description: Maximum value of a floating-point vector.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
* Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
* Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
* Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
* Documentation updated.
*
* Version 1.0.1 2010/10/05
* Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
* Production release and review comments incorporated.
* ---------------------------------------------------------------------------- */
#include "arm_math.h"
/**
* @ingroup groupStats
*/
/**
* @defgroup Max Maximum
*
* Computes the maximum value of an array of data.
* The function returns both the maximum value and its position within the array.
* There are separate functions for floating-point, Q31, Q15, and Q7 data types.
*/
/**
* @addtogroup Max
* @{
*/
/**
* @brief Maximum value of a floating-point vector.
* @param[in] *pSrc points to the input vector
* @param[in] blockSize length of the input vector
* @param[out] *pResult maximum value returned here
* @param[out] *pIndex index of maximum value returned here
* @return none.
*/
void arm_max_f32(
float32_t * pSrc,
uint32_t blockSize,
float32_t * pResult,
uint32_t * pIndex)
{
#ifndef ARM_MATH_CM0
/* Run the below code for Cortex-M4 and Cortex-M3 */
float32_t maxVal1, maxVal2, out; /* Temporary variables to store the output value. */
uint32_t blkCnt, outIndex, count; /* loop counter */
/* Initialise the count value. */
count = 0u;
/* Initialise the index value to zero. */
outIndex = 0u;
/* Load first input value that act as reference value for comparision */
out = *pSrc++;
/* Loop unrolling */
blkCnt = (blockSize - 1u) >> 2u;
/* Run the below code for Cortex-M4 and Cortex-M3 */
while(blkCnt > 0u)
{
/* Initialize maxVal to the next consecutive values one by one */
maxVal1 = *pSrc++;
maxVal2 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal1)
{
/* Update the maximum value and its index */
out = maxVal1;
outIndex = count + 1u;
}
maxVal1 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal2)
{
/* Update the maximum value and its index */
out = maxVal2;
outIndex = count + 2u;
}
maxVal2 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal1)
{
/* Update the maximum value and its index */
out = maxVal1;
outIndex = count + 3u;
}
/* compare for the maximum value */
if(out < maxVal2)
{
/* Update the maximum value and its index */
out = maxVal2;
outIndex = count + 4u;
}
count += 4u;
/* Decrement the loop counter */
blkCnt--;
}
/* if (blockSize - 1u) is not multiple of 4 */
blkCnt = (blockSize - 1u) % 4u;
#else
/* Run the below code for Cortex-M0 */
float32_t maxVal1, out; /* Temporary variables to store the output value. */
uint32_t blkCnt, outIndex; /* loop counter */
/* Initialise the index value to zero. */
outIndex = 0u;
/* Load first input value that act as reference value for comparision */
out = *pSrc++;
blkCnt = (blockSize - 1u);
#endif /* #ifndef ARM_MATH_CM0 */
while(blkCnt > 0u)
{
/* Initialize maxVal to the next consecutive values one by one */
maxVal1 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal1)
{
/* Update the maximum value and it's index */
out = maxVal1;
outIndex = blockSize - blkCnt;
}
/* Decrement the loop counter */
blkCnt--;
}
/* Store the maximum value and it's index into destination pointers */
*pResult = out;
*pIndex = outIndex;
}
/**
* @} end of Max group
*/
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