|
|
/* ----------------------------------------------------------------------
|
|
|
* Copyright (C) 2010 ARM Limited. All rights reserved.
|
|
|
*
|
|
|
* $Date: 29. November 2010
|
|
|
* $Revision: V1.0.3
|
|
|
*
|
|
|
* Project: CMSIS DSP Library
|
|
|
* Title: arm_max_q7.c
|
|
|
*
|
|
|
* Description: Maximum value of a Q7 vector.
|
|
|
*
|
|
|
* Target Processor: Cortex-M4/Cortex-M3
|
|
|
*
|
|
|
* 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
|
|
|
*/
|
|
|
|
|
|
/**
|
|
|
* @addtogroup Max
|
|
|
* @{
|
|
|
*/
|
|
|
|
|
|
|
|
|
/**
|
|
|
* @brief Maximum value of a Q7 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_q7(
|
|
|
q7_t * pSrc,
|
|
|
uint32_t blockSize,
|
|
|
q7_t * pResult,
|
|
|
uint32_t * pIndex)
|
|
|
{
|
|
|
q7_t res, maxVal, x0, x1, maxVal2, maxVal1; /* Temporary variables to store the output value. */
|
|
|
uint32_t blkCnt, index1, index2, index3, indx, indxMod; /* loop counter */
|
|
|
|
|
|
/* Initialise the index value to zero. */
|
|
|
indx = 0u;
|
|
|
|
|
|
/* Load first input value that act as reference value for comparision */
|
|
|
res = *pSrc++;
|
|
|
|
|
|
/* Loop over blockSize number of values */
|
|
|
blkCnt = (blockSize - 1u) >> 2u;
|
|
|
|
|
|
while(blkCnt > 0u)
|
|
|
{
|
|
|
indxMod = blockSize - (blkCnt * 4u);
|
|
|
|
|
|
/* Load two input values for comparision */
|
|
|
x0 = *pSrc++;
|
|
|
x1 = *pSrc++;
|
|
|
|
|
|
if(x0 < x1)
|
|
|
{
|
|
|
/* Update the minimum value and its index */
|
|
|
maxVal1 = x1;
|
|
|
index1 = indxMod + 1u;
|
|
|
}
|
|
|
else
|
|
|
{
|
|
|
/* Update the minimum value and its index */
|
|
|
maxVal1 = x0;
|
|
|
index1 = indxMod;
|
|
|
}
|
|
|
|
|
|
/* Load two input values for comparision */
|
|
|
x0 = *pSrc++;
|
|
|
x1 = *pSrc++;
|
|
|
|
|
|
if(x0 < x1)
|
|
|
{
|
|
|
/* Update the minimum value and its index */
|
|
|
maxVal2 = x1;
|
|
|
index2 = indxMod + 3u;
|
|
|
}
|
|
|
else
|
|
|
{
|
|
|
/* Update the minimum value and its index */
|
|
|
maxVal2 = x0;
|
|
|
index2 = indxMod + 2u;
|
|
|
}
|
|
|
|
|
|
if(maxVal1 < maxVal2)
|
|
|
{
|
|
|
/* Update the minimum value and its index */
|
|
|
maxVal = maxVal2;
|
|
|
index3 = index2;
|
|
|
}
|
|
|
else
|
|
|
{
|
|
|
/* Update the minimum value and its index */
|
|
|
maxVal = maxVal1;
|
|
|
index3 = index1;
|
|
|
}
|
|
|
|
|
|
if(res < maxVal)
|
|
|
{
|
|
|
/* Update the minimum value and its index */
|
|
|
res = maxVal;
|
|
|
indx = index3;
|
|
|
}
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
blkCnt--;
|
|
|
|
|
|
}
|
|
|
|
|
|
blkCnt = (blockSize - 1u) % 0x04u;
|
|
|
|
|
|
while(blkCnt > 0u)
|
|
|
{
|
|
|
/* Initialize maxVal to the next consecutive values one by one */
|
|
|
maxVal = *pSrc++;
|
|
|
|
|
|
/* compare for the maximum value */
|
|
|
if(res < maxVal)
|
|
|
{
|
|
|
/* Update the maximum value and its index */
|
|
|
res = maxVal;
|
|
|
indx = blockSize - blkCnt;
|
|
|
}
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
blkCnt--;
|
|
|
}
|
|
|
|
|
|
/* Store the maximum value and its index into destination pointers */
|
|
|
*pResult = res;
|
|
|
*pIndex = indx;
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @} end of Max group
|
|
|
*/
|
|
|
|
