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/* ----------------------------------------------------------------------
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 * Project:      CMSIS DSP Library
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 * Title:        arm_abs_q31.c
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 * Description:  Q31 vector absolute value
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 *
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 * $Date:        27. January 2017
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 * $Revision:    V.1.5.1
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 *
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 * Target Processor: Cortex-M cores
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 * -------------------------------------------------------------------- */
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/*
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 * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
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 *
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 * SPDX-License-Identifier: Apache-2.0
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 *
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 * Licensed under the Apache License, Version 2.0 (the License); you may
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 * not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 * www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
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 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 */
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#include "arm_math.h"
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/**
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 * @ingroup groupMath
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 */
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/**
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 * @addtogroup BasicAbs
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 * @{
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 */
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/**
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 * @brief Q31 vector absolute value.
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 * @param[in]       *pSrc points to the input buffer
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 * @param[out]      *pDst points to the output buffer
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 * @param[in]       blockSize number of samples in each vector
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 * @return none.
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 *
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 * <b>Scaling and Overflow Behavior:</b>
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 * \par
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 * The function uses saturating arithmetic.
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 * The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
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 */
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void arm_abs_q31(
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  q31_t * pSrc,
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  q31_t * pDst,
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  uint32_t blockSize)
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{
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  uint32_t blkCnt;                               /* loop counter */
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  q31_t in;                                      /* Input value */
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#if defined (ARM_MATH_DSP)
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  /* Run the below code for Cortex-M4 and Cortex-M3 */
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  q31_t in1, in2, in3, in4;
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  /*loop Unrolling */
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  blkCnt = blockSize >> 2U;
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  /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
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   ** a second loop below computes the remaining 1 to 3 samples. */
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  while (blkCnt > 0U)
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  {
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    /* C = |A| */
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    /* Calculate absolute of input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */
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    in1 = *pSrc++;
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    in2 = *pSrc++;
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    in3 = *pSrc++;
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    in4 = *pSrc++;
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    *pDst++ = (in1 > 0) ? in1 : (q31_t)__QSUB(0, in1);
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    *pDst++ = (in2 > 0) ? in2 : (q31_t)__QSUB(0, in2);
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    *pDst++ = (in3 > 0) ? in3 : (q31_t)__QSUB(0, in3);
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    *pDst++ = (in4 > 0) ? in4 : (q31_t)__QSUB(0, in4);
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    /* Decrement the loop counter */
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    blkCnt--;
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  }
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  /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
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   ** No loop unrolling is used. */
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  blkCnt = blockSize % 0x4U;
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#else
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  /* Run the below code for Cortex-M0 */
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  /* Initialize blkCnt with number of samples */
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  blkCnt = blockSize;
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#endif /*   #if defined (ARM_MATH_DSP)   */
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  while (blkCnt > 0U)
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  {
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    /* C = |A| */
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    /* Calculate absolute value of the input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */
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    in = *pSrc++;
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    *pDst++ = (in > 0) ? in : ((in == INT32_MIN) ? INT32_MAX : -in);
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    /* Decrement the loop counter */
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    blkCnt--;
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  }
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}
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/**
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 * @} end of BasicAbs group
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 */