|
|
/* ----------------------------------------------------------------------
|
|
|
* Copyright (C) 2010 ARM Limited. All rights reserved.
|
|
|
*
|
|
|
* $Date: 15. July 2011
|
|
|
* $Revision: V1.0.10
|
|
|
*
|
|
|
* Project: CMSIS DSP Library
|
|
|
* Title: arm_negate_q31.c
|
|
|
*
|
|
|
* Description: Negates Q31 vectors.
|
|
|
*
|
|
|
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
|
|
*
|
|
|
* Version 1.0.10 2011/7/15
|
|
|
* Big Endian support added and Merged M0 and M3/M4 Source code.
|
|
|
*
|
|
|
* Version 1.0.3 2010/11/29
|
|
|
* Re-organized the CMSIS folders and updated documentation.
|
|
|
*
|
|
|
* Version 1.0.2 2010/11/11
|
|
|
* Documentation updated.
|
|
|
*
|
|
|
* Version 1.0.1 2010/10/05
|
|
|
* Production release and review comments incorporated.
|
|
|
*
|
|
|
* Version 1.0.0 2010/09/20
|
|
|
* Production release and review comments incorporated.
|
|
|
*
|
|
|
* Version 0.0.7 2010/06/10
|
|
|
* Misra-C changes done
|
|
|
* -------------------------------------------------------------------- */
|
|
|
|
|
|
#include "arm_math.h"
|
|
|
|
|
|
/**
|
|
|
* @ingroup groupMath
|
|
|
*/
|
|
|
|
|
|
/**
|
|
|
* @addtogroup negate
|
|
|
* @{
|
|
|
*/
|
|
|
|
|
|
/**
|
|
|
* @brief Negates the elements of a Q31 vector.
|
|
|
* @param[in] *pSrc points to the input vector
|
|
|
* @param[out] *pDst points to the output vector
|
|
|
* @param[in] blockSize number of samples in the 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_negate_q31(
|
|
|
q31_t * pSrc,
|
|
|
q31_t * pDst,
|
|
|
uint32_t blockSize)
|
|
|
{
|
|
|
q31_t in; /* Temporary variable */
|
|
|
uint32_t blkCnt; /* loop counter */
|
|
|
|
|
|
#ifndef ARM_MATH_CM0
|
|
|
|
|
|
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
|
|
|
|
|
/*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 */
|
|
|
/* Negate and then store the results in the destination buffer. */
|
|
|
in = *pSrc++;
|
|
|
*pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
|
|
|
in = *pSrc++;
|
|
|
*pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
|
|
|
in = *pSrc++;
|
|
|
*pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
|
|
|
in = *pSrc++;
|
|
|
*pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
|
|
|
|
|
|
/* 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 /* #ifndef ARM_MATH_CM0 */
|
|
|
|
|
|
|
|
|
while(blkCnt > 0u)
|
|
|
{
|
|
|
/* C = -A */
|
|
|
/* Negate and then store the result in the destination buffer. */
|
|
|
in = *pSrc++;
|
|
|
*pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
blkCnt--;
|
|
|
}
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @} end of negate group
|
|
|
*/
|
|
|
|
