272 lines
6.6 KiB
C
272 lines
6.6 KiB
C
/* ----------------------------------------------------------------------
|
|
* Project: CMSIS DSP Library
|
|
* Title: arm_max_f32.c
|
|
* Description: Maximum value of a floating-point vector
|
|
*
|
|
* $Date: 18. March 2019
|
|
* $Revision: V1.6.0
|
|
*
|
|
* Target Processor: Cortex-M cores
|
|
* -------------------------------------------------------------------- */
|
|
/*
|
|
* Copyright (C) 2010-2019 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"
|
|
#if defined(ARM_MATH_NEON)
|
|
#include <limits.h>
|
|
#endif
|
|
|
|
/**
|
|
@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 number of samples in input vector
|
|
@param[out] pResult maximum value returned here
|
|
@param[out] pIndex index of maximum value returned here
|
|
@return none
|
|
*/
|
|
#if defined(ARM_MATH_NEON)
|
|
void arm_max_f32(
|
|
const float32_t * pSrc,
|
|
uint32_t blockSize,
|
|
float32_t * pResult,
|
|
uint32_t * pIndex)
|
|
{
|
|
float32_t maxVal1, maxVal2, out; /* Temporary variables to store the output value. */
|
|
uint32_t blkCnt, outIndex, count; /* loop counter */
|
|
|
|
float32x4_t outV, srcV;
|
|
float32x2_t outV2;
|
|
|
|
uint32x4_t idxV;
|
|
uint32x4_t maxIdx={ULONG_MAX,ULONG_MAX,ULONG_MAX,ULONG_MAX};
|
|
uint32x4_t index={4,5,6,7};
|
|
uint32x4_t delta={4,4,4,4};
|
|
uint32x4_t countV={0,1,2,3};
|
|
uint32x2_t countV2;
|
|
|
|
/* Initialise the count value. */
|
|
count = 0U;
|
|
|
|
/* Initialise the index value to zero. */
|
|
outIndex = 0U;
|
|
|
|
/* Load first input value that act as reference value for comparison */
|
|
if (blockSize <= 3)
|
|
{
|
|
out = *pSrc++;
|
|
|
|
blkCnt = blockSize - 1;
|
|
|
|
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--;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
outV = vld1q_f32(pSrc);
|
|
pSrc += 4;
|
|
|
|
/* Compute 4 outputs at a time */
|
|
blkCnt = (blockSize - 4 ) >> 2U;
|
|
|
|
while (blkCnt > 0U)
|
|
{
|
|
srcV = vld1q_f32(pSrc);
|
|
pSrc += 4;
|
|
|
|
idxV = vcgtq_f32(srcV, outV);
|
|
outV = vbslq_f32(idxV, srcV, outV );
|
|
countV = vbslq_u32(idxV, index,countV );
|
|
|
|
index = vaddq_u32(index,delta);
|
|
|
|
/* Decrement the loop counter */
|
|
blkCnt--;
|
|
}
|
|
|
|
outV2 = vpmax_f32(vget_low_f32(outV),vget_high_f32(outV));
|
|
outV2 = vpmax_f32(outV2,outV2);
|
|
out = outV2[0];
|
|
|
|
idxV = vceqq_f32(outV, vdupq_n_f32(out));
|
|
countV = vbslq_u32(idxV, countV,maxIdx);
|
|
|
|
countV2 = vpmin_u32(vget_low_u32(countV),vget_high_u32(countV));
|
|
countV2 = vpmin_u32(countV2,countV2);
|
|
outIndex = countV2[0];
|
|
|
|
/* if (blockSize - 1U) is not multiple of 4 */
|
|
blkCnt = (blockSize - 4 ) % 4U;
|
|
|
|
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;
|
|
}
|
|
#else
|
|
void arm_max_f32(
|
|
const float32_t * pSrc,
|
|
uint32_t blockSize,
|
|
float32_t * pResult,
|
|
uint32_t * pIndex)
|
|
{
|
|
float32_t maxVal, out; /* Temporary variables to store the output value. */
|
|
uint32_t blkCnt, outIndex; /* Loop counter */
|
|
|
|
#if defined (ARM_MATH_LOOPUNROLL)
|
|
uint32_t index; /* index of maximum value */
|
|
#endif
|
|
|
|
/* Initialise index value to zero. */
|
|
outIndex = 0U;
|
|
|
|
/* Load first input value that act as reference value for comparision */
|
|
out = *pSrc++;
|
|
|
|
#if defined (ARM_MATH_LOOPUNROLL)
|
|
/* Initialise index of maximum value. */
|
|
index = 0U;
|
|
|
|
/* Loop unrolling: Compute 4 outputs at a time */
|
|
blkCnt = (blockSize - 1U) >> 2U;
|
|
|
|
while (blkCnt > 0U)
|
|
{
|
|
/* Initialize maxVal to next consecutive values one by one */
|
|
maxVal = *pSrc++;
|
|
|
|
/* compare for the maximum value */
|
|
if (out < maxVal)
|
|
{
|
|
/* Update the maximum value and it's index */
|
|
out = maxVal;
|
|
outIndex = index + 1U;
|
|
}
|
|
|
|
maxVal = *pSrc++;
|
|
if (out < maxVal)
|
|
{
|
|
out = maxVal;
|
|
outIndex = index + 2U;
|
|
}
|
|
|
|
maxVal = *pSrc++;
|
|
if (out < maxVal)
|
|
{
|
|
out = maxVal;
|
|
outIndex = index + 3U;
|
|
}
|
|
|
|
maxVal = *pSrc++;
|
|
if (out < maxVal)
|
|
{
|
|
out = maxVal;
|
|
outIndex = index + 4U;
|
|
}
|
|
|
|
index += 4U;
|
|
|
|
/* Decrement loop counter */
|
|
blkCnt--;
|
|
}
|
|
|
|
/* Loop unrolling: Compute remaining outputs */
|
|
blkCnt = (blockSize - 1U) % 4U;
|
|
|
|
#else
|
|
|
|
/* Initialize blkCnt with number of samples */
|
|
blkCnt = (blockSize - 1U);
|
|
|
|
#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
|
|
|
|
while (blkCnt > 0U)
|
|
{
|
|
/* Initialize maxVal to the next consecutive values one by one */
|
|
maxVal = *pSrc++;
|
|
|
|
/* compare for the maximum value */
|
|
if (out < maxVal)
|
|
{
|
|
/* Update the maximum value and it's index */
|
|
out = maxVal;
|
|
outIndex = blockSize - blkCnt;
|
|
}
|
|
|
|
/* Decrement loop counter */
|
|
blkCnt--;
|
|
}
|
|
|
|
/* Store the maximum value and it's index into destination pointers */
|
|
*pResult = out;
|
|
*pIndex = outIndex;
|
|
}
|
|
#endif /* #if defined(ARM_MATH_NEON) */
|
|
/**
|
|
@} end of Max group
|
|
*/
|