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CMSIS-DSP/Source/StatisticsFunctions/arm_max_no_idx_q7.c

144 lines
5.1 KiB
C

/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_max_no_idx_q7.c
* Description: Maximum value of a q7 vector without returning the index
*
* $Date: 16 November 2021
* $Revision: V1.10.0
*
* 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.h"
/**
@ingroup groupStats
*/
/**
@addtogroup Max
@{
*/
/**
@brief Maximum value of a q7 vector without index.
@param[in] pSrc points to the input vector
@param[in] blockSize number of samples in input vector
@param[out] pResult maximum value returned here
@return none
*/
#if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
#include "arm_helium_utils.h"
void arm_max_no_idx_q7(
const q7_t * pSrc,
uint32_t blockSize,
q7_t * pResult)
{
int32_t blkCnt; /* loop counters */
q7x16_t vecSrc;
q7_t const *pSrcVec;
q7x16_t curExtremValVec = vdupq_n_s8(Q7_MIN);
q7_t maxValue = Q7_MIN;
mve_pred16_t p0;
pSrcVec = (q7_t const *) pSrc;
blkCnt = blockSize >> 4;
while (blkCnt > 0)
{
vecSrc = vld1q(pSrcVec);
pSrcVec += 16;
/*
* update per-lane max.
*/
curExtremValVec = vmaxq(vecSrc, curExtremValVec);
/*
* Decrement the blockSize loop counter
*/
blkCnt--;
}
/*
* tail
* (will be merged thru tail predication)
*/
blkCnt = blockSize & 0xF;
if (blkCnt > 0)
{
vecSrc = vld1q(pSrcVec);
pSrcVec += 16;
p0 = vctp8q(blkCnt);
/*
* Get current max per lane and current index per lane
* when a max is selected
*/
curExtremValVec = vmaxq_m(curExtremValVec, vecSrc, curExtremValVec, p0);
}
/*
* Get max value across the vector
*/
maxValue = vmaxvq(maxValue, curExtremValVec);
*pResult = maxValue;
}
#else
void arm_max_no_idx_q7(
const q7_t * pSrc,
uint32_t blockSize,
q7_t * pResult)
{
q7_t maxVal1, out; /* Temporary variables to store the output value. */
uint32_t blkCnt; /* loop counter */
/* Load first input value that act as reference value for comparision */
out = *pSrc++;
blkCnt = (blockSize - 1U);
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 */
out = maxVal1;
}
/* Decrement the loop counter */
blkCnt--;
}
/* Store the maximum value into destination pointer */
*pResult = out;
}
#endif /* #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE) */
/**
@} end of Max group
*/