You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
142 lines
4.4 KiB
142 lines
4.4 KiB
/* ----------------------------------------------------------------------
|
|
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
|
|
*
|
|
* $Date: 12. March 2014
|
|
* $Revision: V1.4.4
|
|
*
|
|
* Project: CMSIS DSP Library
|
|
* Title: arm_negate_q15.c
|
|
*
|
|
* Description: Negates Q15 vectors.
|
|
*
|
|
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* - Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* - Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* - Neither the name of ARM LIMITED nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this
|
|
* software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
* -------------------------------------------------------------------- */
|
|
#include "arm_math.h"
|
|
|
|
/**
|
|
* @ingroup groupMath
|
|
*/
|
|
|
|
/**
|
|
* @addtogroup negate
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* @brief Negates the elements of a Q15 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.
|
|
*
|
|
* \par Conditions for optimum performance
|
|
* Input and output buffers should be aligned by 32-bit
|
|
*
|
|
*
|
|
* <b>Scaling and Overflow Behavior:</b>
|
|
* \par
|
|
* The function uses saturating arithmetic.
|
|
* The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
|
|
*/
|
|
|
|
void arm_negate_q15(
|
|
q15_t * pSrc,
|
|
q15_t * pDst,
|
|
uint32_t blockSize)
|
|
{
|
|
uint32_t blkCnt; /* loop counter */
|
|
q15_t in;
|
|
|
|
#ifndef ARM_MATH_CM0_FAMILY
|
|
|
|
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
|
|
|
q31_t in1, in2; /* Temporary variables */
|
|
|
|
|
|
/*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 */
|
|
/* Read two inputs at a time */
|
|
in1 = _SIMD32_OFFSET(pSrc);
|
|
in2 = _SIMD32_OFFSET(pSrc + 2);
|
|
|
|
/* negate two samples at a time */
|
|
in1 = __QSUB16(0, in1);
|
|
|
|
/* negate two samples at a time */
|
|
in2 = __QSUB16(0, in2);
|
|
|
|
/* store the result to destination 2 samples at a time */
|
|
_SIMD32_OFFSET(pDst) = in1;
|
|
/* store the result to destination 2 samples at a time */
|
|
_SIMD32_OFFSET(pDst + 2) = in2;
|
|
|
|
|
|
/* update pointers to process next samples */
|
|
pSrc += 4u;
|
|
pDst += 4u;
|
|
|
|
/* 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_FAMILY */
|
|
|
|
while(blkCnt > 0u)
|
|
{
|
|
/* C = -A */
|
|
/* Negate and then store the result in the destination buffer. */
|
|
in = *pSrc++;
|
|
*pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;
|
|
|
|
/* Decrement the loop counter */
|
|
blkCnt--;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @} end of negate group
|
|
*/
|
|
|