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/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_mat_scale_q31.c
* Description: Multiplies a Q31 matrix by a scalar
*
* $Date: 18. March 2019
* $Revision: V1.6.0
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2019 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 groupMatrix
*/
/**
@addtogroup MatrixScale
@{
*/
/**
@brief Q31 matrix scaling.
@param[in] pSrc points to input matrix
@param[in] scaleFract fractional portion of the scale factor
@param[in] shift number of bits to shift the result by
@param[out] pDst points to output matrix structure
@return execution status
- \ref ARM_MATH_SUCCESS : Operation successful
- \ref ARM_MATH_SIZE_MISMATCH : Matrix size check failed
@par Scaling and Overflow Behavior
The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.31 format.
These are multiplied to yield a 2.62 intermediate result which is shifted with saturation to 1.31 format.
*/
arm_status arm_mat_scale_q31(
const arm_matrix_instance_q31 * pSrc,
q31_t scaleFract,
int32_t shift,
arm_matrix_instance_q31 * pDst)
{
q31_t *pIn = pSrc->pData; /* Input data matrix pointer */
q31_t *pOut = pDst->pData; /* Output data matrix pointer */
uint32_t numSamples; /* Total number of elements in the matrix */
uint32_t blkCnt; /* Loop counter */
arm_status status; /* Status of matrix scaling */
int32_t kShift = shift + 1; /* Shift to apply after scaling */
q31_t in, out; /* Temporary variabels */
#ifdef ARM_MATH_MATRIX_CHECK
/* Check for matrix mismatch condition */
if ((pSrc->numRows != pDst->numRows) ||
(pSrc->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 input matrix */
numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
#if defined (ARM_MATH_LOOPUNROLL)
/* Loop unrolling: Compute 4 outputs at a time */
blkCnt = numSamples >> 2U;
while (blkCnt > 0U)
{
/* C(m,n) = A(m,n) * k */
/* Scale, saturate and store result in destination buffer. */
in = *pIn++; /* read four inputs from source */
in = ((q63_t) in * scaleFract) >> 32; /* multiply input with scaler value */
out = in << kShift; /* apply shifting */
if (in != (out >> kShift)) /* saturate the results. */
out = 0x7FFFFFFF ^ (in >> 31);
*pOut++ = out; /* Store result destination */
in = *pIn++;
in = ((q63_t) in * scaleFract) >> 32;
out = in << kShift;
if (in != (out >> kShift))
out = 0x7FFFFFFF ^ (in >> 31);
*pOut++ = out;
in = *pIn++;
in = ((q63_t) in * scaleFract) >> 32;
out = in << kShift;
if (in != (out >> kShift))
out = 0x7FFFFFFF ^ (in >> 31);
*pOut++ = out;
in = *pIn++;
in = ((q63_t) in * scaleFract) >> 32;
out = in << kShift;
if (in != (out >> kShift))
out = 0x7FFFFFFF ^ (in >> 31);
*pOut++ = out;
/* Decrement loop counter */
blkCnt--;
}
/* Loop unrolling: Compute remaining outputs */
blkCnt = numSamples % 0x4U;
#else
/* Initialize blkCnt with number of samples */
blkCnt = numSamples;
#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
while (blkCnt > 0U)
{
/* C(m,n) = A(m,n) * k */
/* Scale, saturate and store result in destination buffer. */
in = *pIn++;
in = ((q63_t) in * scaleFract) >> 32;
out = in << kShift;
if (in != (out >> kShift))
out = 0x7FFFFFFF ^ (in >> 31);
*pOut++ = out;
/* Decrement loop counter */
blkCnt--;
}
/* Set status as ARM_MATH_SUCCESS */
status = ARM_MATH_SUCCESS;
}
/* Return to application */
return (status);
}
/**
@} end of MatrixScale group
*/