/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_absmax_q31.c
* Description: Maximum value of absolute values of a Q31 vector
*
* $Date: 23 April 2021
* $Revision: V1.9.0
*
* 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 AbsMax
@{
*/
/**
@brief Maximum value of absolute values of a Q31 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_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
#include "arm_helium_utils.h"
void arm_absmax_q31(
const q31_t * pSrc,
uint32_t blockSize,
q31_t * pResult,
uint32_t * pIndex)
{
int32_t blkCnt; /* loop counters */
q31x4_t extremValVec = vdupq_n_s32(Q31_ABSMIN);
q31_t maxValue = Q31_ABSMIN;
uint32x4_t indexVec;
uint32x4_t extremIdxVec;
mve_pred16_t p0;
uint32_t extremIdxArr[4];
indexVec = vidupq_u32(0U, 1);
blkCnt = blockSize;
do {
mve_pred16_t p = vctp32q(blkCnt);
q31x4_t extremIdxVal = vld1q_z_s32(pSrc, p);
extremIdxVal = vqabsq(extremIdxVal);
/*
* Get current max per lane and current index per lane
* when a max is selected
*/
p0 = vcmpgeq_m(extremIdxVal, extremValVec, p);
extremValVec = vorrq_m(extremValVec, extremIdxVal, extremIdxVal, p0);
/* store per-lane extrema indexes */
vst1q_p_u32(extremIdxArr, indexVec, p0);
indexVec += 4;
pSrc += 4;
blkCnt -= 4;
}
while (blkCnt > 0);
/* Get max value across the vector */
maxValue = vmaxvq(maxValue, extremValVec);
/* set index for lower values to max possible index */
p0 = vcmpgeq(extremValVec, maxValue);
extremIdxVec = vld1q_u32(extremIdxArr);
indexVec = vpselq(extremIdxVec, vdupq_n_u32(blockSize - 1), p0);
*pIndex = vminvq(blockSize - 1, indexVec);
*pResult = maxValue;
}
#else
#if defined(ARM_MATH_DSP)
void arm_absmax_q31(
const q31_t * pSrc,
uint32_t blockSize,
q31_t * pResult,
uint32_t * pIndex)
{
q31_t cur_absmax, out; /* Temporary variables to store the output value. */\
uint32_t blkCnt, outIndex; /* Loop counter */ \
uint32_t index; /* index of maximum value */ \
\
/* Initialize index value to zero. */ \
outIndex = 0U; \
/* Load first input value that act as reference value for comparision */ \
out = *pSrc++; \
out = (out > 0) ? out : (q31_t)__QSUB(0, out); \
/* Initialize index of extrema value. */ \
index = 0U; \
\
/* Loop unrolling: Compute 4 outputs at a time */ \
blkCnt = (blockSize - 1U) >> 2U; \
\
while (blkCnt > 0U) \
{ \
/* Initialize cur_absmax to next consecutive values one by one */ \
cur_absmax = *pSrc++; \
cur_absmax = (cur_absmax > 0) ? cur_absmax : (q31_t)__QSUB(0, cur_absmax); \
/* compare for the extrema value */ \
if (cur_absmax > out) \
{ \
/* Update the extrema value and it's index */ \
out = cur_absmax; \
outIndex = index + 1U; \
} \
\
cur_absmax = *pSrc++; \
cur_absmax = (cur_absmax > 0) ? cur_absmax : (q31_t)__QSUB(0, cur_absmax); \
if (cur_absmax > out) \
{ \
out = cur_absmax; \
outIndex = index + 2U; \
} \
\
cur_absmax = *pSrc++; \
cur_absmax = (cur_absmax > 0) ? cur_absmax : (q31_t)__QSUB(0, cur_absmax); \
if (cur_absmax > out) \
{ \
out = cur_absmax; \
outIndex = index + 3U; \
} \
\
cur_absmax = *pSrc++; \
cur_absmax = (cur_absmax > 0) ? cur_absmax : (q31_t)__QSUB(0, cur_absmax); \
if (cur_absmax > out) \
{ \
out = cur_absmax; \
outIndex = index + 4U; \
} \
\
index += 4U; \
\
/* Decrement loop counter */ \
blkCnt--; \
} \
\
/* Loop unrolling: Compute remaining outputs */ \
blkCnt = (blockSize - 1U) % 4U; \
\
\
while (blkCnt > 0U) \
{ \
cur_absmax = *pSrc++; \
cur_absmax = (cur_absmax > 0) ? cur_absmax : (q31_t)__QSUB(0, cur_absmax); \
if (cur_absmax > out) \
{ \
out = cur_absmax; \
outIndex = blockSize - blkCnt; \
} \
\
/* Decrement loop counter */ \
blkCnt--; \
} \
\
/* Store the extrema value and it's index into destination pointers */ \
*pResult = out; \
*pIndex = outIndex;
}
#else
void arm_absmax_q31(
const q31_t * pSrc,
uint32_t blockSize,
q31_t * pResult,
uint32_t * pIndex)
{
q31_t maxVal, out; /* Temporary variables to store the output value. */
uint32_t blkCnt, outIndex; /* Loop counter */
/* Initialise index value to zero. */
outIndex = 0U;
/* Load first input value that act as reference value for comparision */
out = (*pSrc > 0) ? *pSrc : ((*pSrc == INT32_MIN) ? INT32_MAX : -*pSrc);
pSrc++;
/* Initialize blkCnt with number of samples */
blkCnt = (blockSize - 1U);
while (blkCnt > 0U)
{
/* Initialize maxVal to the next consecutive values one by one */
maxVal = (*pSrc > 0) ? *pSrc : ((*pSrc == INT32_MIN) ? INT32_MAX : -*pSrc);
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 /* defined(ARM_MATH_DSP) */
#endif /* defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE) */
/**
@} end of AbsMax group
*/