/* ----------------------------------------------------------------------
|
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
|
*
|
* $Date: 19. March 2015
|
* $Revision: V.1.4.5
|
*
|
* Project: CMSIS DSP Library
|
* Title: arm_mat_sub_q15.c
|
*
|
* Description: Q15 Matrix subtraction
|
*
|
* 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 groupMatrix
|
*/
|
|
/**
|
* @addtogroup MatrixSub
|
* @{
|
*/
|
|
/**
|
* @brief Q15 matrix subtraction.
|
* @param[in] *pSrcA points to the first input matrix structure
|
* @param[in] *pSrcB points to the second input matrix structure
|
* @param[out] *pDst points to output matrix structure
|
* @return The function returns either
|
* <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
|
*
|
* <b>Scaling and Overflow Behavior:</b>
|
* \par
|
* The function uses saturating arithmetic.
|
* Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.
|
*/
|
|
arm_status arm_mat_sub_q15(
|
const arm_matrix_instance_q15 * pSrcA,
|
const arm_matrix_instance_q15 * pSrcB,
|
arm_matrix_instance_q15 * pDst)
|
{
|
q15_t *pInA = pSrcA->pData; /* input data matrix pointer A */
|
q15_t *pInB = pSrcB->pData; /* input data matrix pointer B */
|
q15_t *pOut = pDst->pData; /* output data matrix pointer */
|
uint32_t numSamples; /* total number of elements in the matrix */
|
uint32_t blkCnt; /* loop counters */
|
arm_status status; /* status of matrix subtraction */
|
|
|
#ifdef ARM_MATH_MATRIX_CHECK
|
|
|
/* Check for matrix mismatch condition */
|
if((pSrcA->numRows != pSrcB->numRows) ||
|
(pSrcA->numCols != pSrcB->numCols) ||
|
(pSrcA->numRows != pDst->numRows) || (pSrcA->numCols != pDst->numCols))
|
{
|
/* Set status as ARM_MATH_SIZE_MISMATCH */
|
status = ARM_MATH_SIZE_MISMATCH;
|
}
|
else
|
#endif /* #ifdef ARM_MATH_MATRIX_CHECK */
|
|
{
|
/* Total number of samples in the input matrix */
|
numSamples = (uint32_t) pSrcA->numRows * pSrcA->numCols;
|
|
#ifndef ARM_MATH_CM0_FAMILY
|
|
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
|
/* Apply loop unrolling */
|
blkCnt = numSamples >> 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(m,n) = A(m,n) - B(m,n) */
|
/* Subtract, Saturate and then store the results in the destination buffer. */
|
*__SIMD32(pOut)++ = __QSUB16(*__SIMD32(pInA)++, *__SIMD32(pInB)++);
|
*__SIMD32(pOut)++ = __QSUB16(*__SIMD32(pInA)++, *__SIMD32(pInB)++);
|
|
/* 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 = numSamples % 0x4u;
|
|
while(blkCnt > 0u)
|
{
|
/* C(m,n) = A(m,n) - B(m,n) */
|
/* Subtract and then store the results in the destination buffer. */
|
*pOut++ = (q15_t) __QSUB16(*pInA++, *pInB++);
|
|
/* Decrement the loop counter */
|
blkCnt--;
|
}
|
|
#else
|
|
/* Run the below code for Cortex-M0 */
|
|
/* Initialize blkCnt with number of samples */
|
blkCnt = numSamples;
|
|
while(blkCnt > 0u)
|
{
|
/* C(m,n) = A(m,n) - B(m,n) */
|
/* Subtract and then store the results in the destination buffer. */
|
*pOut++ = (q15_t) __SSAT(((q31_t) * pInA++ - *pInB++), 16);
|
|
/* Decrement the loop counter */
|
blkCnt--;
|
}
|
|
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
|
/* Set status as ARM_MATH_SUCCESS */
|
status = ARM_MATH_SUCCESS;
|
}
|
|
/* Return to application */
|
return (status);
|
}
|
|
/**
|
* @} end of MatrixSub group
|
*/
|
