/* ----------------------------------------------------------------------
* 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_scale_q31.c
*
* Description: Multiplies a Q31 matrix by a scalar.
*
* 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 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 The function returns either
* <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
*
* @details
* <b>Scaling and Overflow Behavior:</b>
* \par
* 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 and this 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 */
int32_t totShift = shift + 1; /* shift to apply after scaling */
uint32_t blkCnt; /* loop counters */
arm_status status; /* status of matrix scaling */
q31_t in1, in2, out1; /* temporary variabels */
#ifndef ARM_MATH_CM0_FAMILY
q31_t in3, in4, out2, out3, out4; /* temporary variables */
#endif // #ifndef ARM_MAT_CM0
#ifdef ARM_MATH_MATRIX_CHECK
/* Check for matrix mismatch */
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 the input matrix */
numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
#ifndef ARM_MATH_CM0_FAMILY
/* Run the below code for Cortex-M4 and Cortex-M3 */
/* 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) * k */
/* Read values from input */
in1 = *pIn;
in2 = *(pIn + 1);
in3 = *(pIn + 2);
in4 = *(pIn + 3);
/* multiply input with scaler value */
in1 = ((q63_t) in1 * scaleFract) >> 32;
in2 = ((q63_t) in2 * scaleFract) >> 32;
in3 = ((q63_t) in3 * scaleFract) >> 32;
in4 = ((q63_t) in4 * scaleFract) >> 32;
/* apply shifting */
out1 = in1 << totShift;
out2 = in2 << totShift;
/* saturate the results. */
if(in1 != (out1 >> totShift))
out1 = 0x7FFFFFFF ^ (in1 >> 31);
if(in2 != (out2 >> totShift))
out2 = 0x7FFFFFFF ^ (in2 >> 31);
out3 = in3 << totShift;
out4 = in4 << totShift;
*pOut = out1;
*(pOut + 1) = out2;
if(in3 != (out3 >> totShift))
out3 = 0x7FFFFFFF ^ (in3 >> 31);
if(in4 != (out4 >> totShift))
out4 = 0x7FFFFFFF ^ (in4 >> 31);
*(pOut + 2) = out3;
*(pOut + 3) = out4;
/* update pointers to process next sampels */
pIn += 4u;
pOut += 4u;
/* Decrement the numSamples loop counter */
blkCnt--;
}
/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
** No loop unrolling is used. */
blkCnt = numSamples % 0x4u;
#else
/* Run the below code for Cortex-M0 */
/* Initialize blkCnt with number of samples */
blkCnt = numSamples;
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
while(blkCnt > 0u)
{
/* C(m,n) = A(m,n) * k */
/* Scale, saturate and then store the results in the destination buffer. */
in1 = *pIn++;
in2 = ((q63_t) in1 * scaleFract) >> 32;
out1 = in2 << totShift;
if(in2 != (out1 >> totShift))
out1 = 0x7FFFFFFF ^ (in2 >> 31);
*pOut++ = out1;
/* Decrement the numSamples loop counter */
blkCnt--;
}
/* Set status as ARM_MATH_SUCCESS */
status = ARM_MATH_SUCCESS;
}
/* Return to application */
return (status);
}
/**
* @} end of MatrixScale group
*/