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/* ----------------------------------------------------------------------    

* 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        

 */