118 lines
3.3 KiB
C
118 lines
3.3 KiB
C
/* ----------------------------------------------------------------------
|
|
* Project: CMSIS DSP Library
|
|
* Title: arm_abs_q31.c
|
|
* Description: Q31 vector absolute value
|
|
*
|
|
* $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 groupMath
|
|
*/
|
|
|
|
/**
|
|
* @addtogroup BasicAbs
|
|
* @{
|
|
*/
|
|
|
|
|
|
/**
|
|
* @brief Q31 vector absolute value.
|
|
* @param[in] *pSrc points to the input buffer
|
|
* @param[out] *pDst points to the output buffer
|
|
* @param[in] blockSize number of samples in each vector
|
|
* @return none.
|
|
*
|
|
* <b>Scaling and Overflow Behavior:</b>
|
|
* \par
|
|
* The function uses saturating arithmetic.
|
|
* The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
|
|
*/
|
|
|
|
void arm_abs_q31(
|
|
q31_t * pSrc,
|
|
q31_t * pDst,
|
|
uint32_t blockSize)
|
|
{
|
|
uint32_t blkCnt; /* loop counter */
|
|
q31_t in; /* Input value */
|
|
|
|
#if defined (ARM_MATH_DSP)
|
|
|
|
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
|
q31_t in1, in2, in3, in4;
|
|
|
|
/*loop Unrolling */
|
|
blkCnt = blockSize >> 2u;
|
|
|
|
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
|
|
** a second loop below computes the remaining 1 to 3 samples. */
|
|
while (blkCnt > 0u)
|
|
{
|
|
/* C = |A| */
|
|
/* Calculate absolute of input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */
|
|
in1 = *pSrc++;
|
|
in2 = *pSrc++;
|
|
in3 = *pSrc++;
|
|
in4 = *pSrc++;
|
|
|
|
*pDst++ = (in1 > 0) ? in1 : (q31_t)__QSUB(0, in1);
|
|
*pDst++ = (in2 > 0) ? in2 : (q31_t)__QSUB(0, in2);
|
|
*pDst++ = (in3 > 0) ? in3 : (q31_t)__QSUB(0, in3);
|
|
*pDst++ = (in4 > 0) ? in4 : (q31_t)__QSUB(0, in4);
|
|
|
|
/* Decrement the loop counter */
|
|
blkCnt--;
|
|
}
|
|
|
|
/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
|
|
** No loop unrolling is used. */
|
|
blkCnt = blockSize % 0x4u;
|
|
|
|
#else
|
|
|
|
/* Run the below code for Cortex-M0 */
|
|
|
|
/* Initialize blkCnt with number of samples */
|
|
blkCnt = blockSize;
|
|
|
|
#endif /* #if defined (ARM_MATH_DSP) */
|
|
|
|
while (blkCnt > 0u)
|
|
{
|
|
/* C = |A| */
|
|
/* Calculate absolute value of the input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */
|
|
in = *pSrc++;
|
|
*pDst++ = (in > 0) ? in : ((in == INT32_MIN) ? INT32_MAX : -in);
|
|
|
|
/* Decrement the loop counter */
|
|
blkCnt--;
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @} end of BasicAbs group
|
|
*/
|