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/* ----------------------------------------------------------------------    
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* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
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*    
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* $Date:        19. March 2015
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* $Revision:    V.1.4.5
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*    
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* Project:          CMSIS DSP Library    
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* Title:            arm_mat_scale_q15.c    
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*    
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* Description:  Multiplies a Q15 matrix by a scalar.    
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*    
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* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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*  
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*   - Redistributions of source code must retain the above copyright
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*     notice, this list of conditions and the following disclaimer.
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*   - Redistributions in binary form must reproduce the above copyright
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*     notice, this list of conditions and the following disclaimer in
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*     the documentation and/or other materials provided with the
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*     distribution.
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*   - Neither the name of ARM LIMITED nor the names of its contributors
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*     may be used to endorse or promote products derived from this
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*     software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.  
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* -------------------------------------------------------------------- */
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#include "arm_math.h"
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/**    
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 * @ingroup groupMatrix    
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 */
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/**    
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 * @addtogroup MatrixScale    
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 * @{    
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 */
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/**    
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 * @brief Q15 matrix scaling.    
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 * @param[in]       *pSrc points to input matrix    
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 * @param[in]       scaleFract fractional portion of the scale factor    
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 * @param[in]       shift number of bits to shift the result by    
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 * @param[out]      *pDst points to output matrix structure    
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 * @return              The function returns either    
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 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.    
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 *    
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 * @details    
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 * <b>Scaling and Overflow Behavior:</b>    
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 * \par    
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 * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.    
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 * These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.    
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 */
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arm_status arm_mat_scale_q15(
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  const arm_matrix_instance_q15 * pSrc,
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  q15_t scaleFract,
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  int32_t shift,
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  arm_matrix_instance_q15 * pDst)
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{
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  q15_t *pIn = pSrc->pData;                      /* input data matrix pointer */
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  q15_t *pOut = pDst->pData;                     /* output data matrix pointer */
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  uint32_t numSamples;                           /* total number of elements in the matrix */
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  int32_t totShift = 15 - shift;                 /* total shift to apply after scaling */
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  uint32_t blkCnt;                               /* loop counters */
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  arm_status status;                             /* status of matrix scaling     */
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#ifndef ARM_MATH_CM0_FAMILY
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  q15_t in1, in2, in3, in4;
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  q31_t out1, out2, out3, out4;
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  q31_t inA1, inA2;
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#endif //     #ifndef ARM_MATH_CM0_FAMILY
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#ifdef ARM_MATH_MATRIX_CHECK
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  /* Check for matrix mismatch */
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  if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
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  {
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    /* Set status as ARM_MATH_SIZE_MISMATCH */
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    status = ARM_MATH_SIZE_MISMATCH;
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  }
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  else
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#endif //    #ifdef ARM_MATH_MATRIX_CHECK
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  {
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    /* Total number of samples in the input matrix */
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    numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
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#ifndef ARM_MATH_CM0_FAMILY
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    /* Run the below code for Cortex-M4 and Cortex-M3 */
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    /* Loop Unrolling */
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    blkCnt = numSamples >> 2;
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    /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
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     ** a second loop below computes the remaining 1 to 3 samples. */
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    while(blkCnt > 0u)
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    {
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      /* C(m,n) = A(m,n) * k */
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      /* Scale, saturate and then store the results in the destination buffer. */
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      /* Reading 2 inputs from memory */
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      inA1 = _SIMD32_OFFSET(pIn);
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      inA2 = _SIMD32_OFFSET(pIn + 2);
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      /* C = A * scale */
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      /* Scale the inputs and then store the 2 results in the destination buffer        
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       * in single cycle by packing the outputs */
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      out1 = (q31_t) ((q15_t) (inA1 >> 16) * scaleFract);
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      out2 = (q31_t) ((q15_t) inA1 * scaleFract);
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      out3 = (q31_t) ((q15_t) (inA2 >> 16) * scaleFract);
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      out4 = (q31_t) ((q15_t) inA2 * scaleFract);
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      out1 = out1 >> totShift;
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      inA1 = _SIMD32_OFFSET(pIn + 4);
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      out2 = out2 >> totShift;
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      inA2 = _SIMD32_OFFSET(pIn + 6);
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      out3 = out3 >> totShift;
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      out4 = out4 >> totShift;
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      in1 = (q15_t) (__SSAT(out1, 16));
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      in2 = (q15_t) (__SSAT(out2, 16));
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      in3 = (q15_t) (__SSAT(out3, 16));
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      in4 = (q15_t) (__SSAT(out4, 16));
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      _SIMD32_OFFSET(pOut) = __PKHBT(in2, in1, 16);
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      _SIMD32_OFFSET(pOut + 2) = __PKHBT(in4, in3, 16);
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      /* update pointers to process next sampels */
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      pIn += 4u;
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      pOut += 4u;
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      /* Decrement the numSamples loop counter */
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      blkCnt--;
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    }
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    /* If the numSamples is not a multiple of 4, compute any remaining output samples here.        
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     ** No loop unrolling is used. */
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    blkCnt = numSamples % 0x4u;
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#else
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    /* Run the below code for Cortex-M0 */
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    /* Initialize blkCnt with number of samples */
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    blkCnt = numSamples;
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#endif /* #ifndef ARM_MATH_CM0_FAMILY */
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    while(blkCnt > 0u)
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    {
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      /* C(m,n) = A(m,n) * k */
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      /* Scale, saturate and then store the results in the destination buffer. */
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      *pOut++ =
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        (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
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      /* Decrement the numSamples loop counter */
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      blkCnt--;
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    }
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    /* Set status as ARM_MATH_SUCCESS */
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    status = ARM_MATH_SUCCESS;
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  }
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  /* Return to application */
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  return (status);
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}
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/**        
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 * @} end of MatrixScale group        
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 */