xmclib/CMSIS/DSP_Lib/Source/StatisticsFunctions/arm_min_q15.c
2024-10-17 17:09:59 +02:00

163 lines
4.2 KiB
C

/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_min_q15.c
* Description: Minimum value of a Q15 vector
*
* $Date: 27. January 2017
* $Revision: V.1.5.1
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2017 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"
/**
* @ingroup groupStats
*/
/**
* @addtogroup Min
* @{
*/
/**
* @brief Minimum value of a Q15 vector.
* @param[in] *pSrc points to the input vector
* @param[in] blockSize length of the input vector
* @param[out] *pResult minimum value returned here
* @param[out] *pIndex index of minimum value returned here
* @return none.
*/
void arm_min_q15(
q15_t * pSrc,
uint32_t blockSize,
q15_t * pResult,
uint32_t * pIndex)
{
#if defined (ARM_MATH_DSP)
/* Run the below code for Cortex-M4 and Cortex-M3 */
q15_t minVal1, minVal2, 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;
while (blkCnt > 0u)
{
/* Initialize minVal to the next consecutive values one by one */
minVal1 = *pSrc++;
minVal2 = *pSrc++;
/* compare for the minimum value */
if (out > minVal1)
{
/* Update the minimum value and its index */
out = minVal1;
outIndex = count + 1u;
}
/* compare for the minimum value */
if (out > minVal2)
{
/* Update the minimum value and its index */
out = minVal2;
outIndex = count + 2u;
}
/* Initialize minVal to the next consecutive values one by one */
minVal1 = *pSrc++;
minVal2 = *pSrc++;
/* compare for the minimum value */
if (out > minVal1)
{
/* Update the minimum value and its index */
out = minVal1;
outIndex = count + 3u;
}
/* compare for the minimum value */
if (out > minVal2)
{
/* Update the minimum value and its index */
out = minVal2;
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 */
q15_t minVal1, 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 /* #if defined (ARM_MATH_DSP) */
while (blkCnt > 0u)
{
/* Initialize minVal to the next consecutive values one by one */
minVal1 = *pSrc++;
/* compare for the minimum value */
if (out > minVal1)
{
/* Update the minimum value and it's index */
out = minVal1;
outIndex = blockSize - blkCnt;
}
/* Decrement the loop counter */
blkCnt--;
}
/* Store the minimum value and it's index into destination pointers */
*pResult = out;
*pIndex = outIndex;
}
/**
* @} end of Min group
*/