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  1. /* ----------------------------------------------------------------------    
  2. * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  3. *    
  4. * $Date:        19. March 2015
  5. * $Revision:    V.1.4.5
  6. *    
  7. * Project:          CMSIS DSP Library    
  8. * Title:            arm_mat_scale_q15.c    
  9. *    
  10. * Description:  Multiplies a Q15 matrix by a scalar.    
  11. *    
  12. * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  13. *  
  14. * Redistribution and use in source and binary forms, with or without
  15. * modification, are permitted provided that the following conditions
  16. * are met:
  17. *   - Redistributions of source code must retain the above copyright
  18. *     notice, this list of conditions and the following disclaimer.
  19. *   - Redistributions in binary form must reproduce the above copyright
  20. *     notice, this list of conditions and the following disclaimer in
  21. *     the documentation and/or other materials provided with the
  22. *     distribution.
  23. *   - Neither the name of ARM LIMITED nor the names of its contributors
  24. *     may be used to endorse or promote products derived from this
  25. *     software without specific prior written permission.
  26. *
  27. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28. * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29. * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  30. * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  31. * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  32. * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  33. * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  34. * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  35. * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  37. * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38. * POSSIBILITY OF SUCH DAMAGE.  
  39. * -------------------------------------------------------------------- */
  40.  
  41. #include "arm_math.h"
  42.  
  43. /**    
  44.  * @ingroup groupMatrix    
  45.  */
  46.  
  47. /**    
  48.  * @addtogroup MatrixScale    
  49.  * @{    
  50.  */
  51.  
  52. /**    
  53.  * @brief Q15 matrix scaling.    
  54.  * @param[in]       *pSrc points to input matrix    
  55.  * @param[in]       scaleFract fractional portion of the scale factor    
  56.  * @param[in]       shift number of bits to shift the result by    
  57.  * @param[out]      *pDst points to output matrix structure    
  58.  * @return              The function returns either    
  59.  * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.    
  60.  *    
  61.  * @details    
  62.  * <b>Scaling and Overflow Behavior:</b>    
  63.  * \par    
  64.  * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.    
  65.  * These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.    
  66.  */
  67.  
  68. arm_status arm_mat_scale_q15(
  69.   const arm_matrix_instance_q15 * pSrc,
  70.   q15_t scaleFract,
  71.   int32_t shift,
  72.   arm_matrix_instance_q15 * pDst)
  73. {
  74.   q15_t *pIn = pSrc->pData;                      /* input data matrix pointer */
  75.   q15_t *pOut = pDst->pData;                     /* output data matrix pointer */
  76.   uint32_t numSamples;                           /* total number of elements in the matrix */
  77.   int32_t totShift = 15 - shift;                 /* total shift to apply after scaling */
  78.   uint32_t blkCnt;                               /* loop counters */
  79.   arm_status status;                             /* status of matrix scaling     */
  80.  
  81. #ifndef ARM_MATH_CM0_FAMILY
  82.  
  83.   q15_t in1, in2, in3, in4;
  84.   q31_t out1, out2, out3, out4;
  85.   q31_t inA1, inA2;
  86.  
  87. #endif //     #ifndef ARM_MATH_CM0_FAMILY
  88.  
  89. #ifdef ARM_MATH_MATRIX_CHECK
  90.   /* Check for matrix mismatch */
  91.   if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
  92.   {
  93.     /* Set status as ARM_MATH_SIZE_MISMATCH */
  94.     status = ARM_MATH_SIZE_MISMATCH;
  95.   }
  96.   else
  97. #endif //    #ifdef ARM_MATH_MATRIX_CHECK
  98.   {
  99.     /* Total number of samples in the input matrix */
  100.     numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
  101.  
  102. #ifndef ARM_MATH_CM0_FAMILY
  103.  
  104.     /* Run the below code for Cortex-M4 and Cortex-M3 */
  105.     /* Loop Unrolling */
  106.     blkCnt = numSamples >> 2;
  107.  
  108.     /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
  109.      ** a second loop below computes the remaining 1 to 3 samples. */
  110.     while(blkCnt > 0u)
  111.     {
  112.       /* C(m,n) = A(m,n) * k */
  113.       /* Scale, saturate and then store the results in the destination buffer. */
  114.       /* Reading 2 inputs from memory */
  115.       inA1 = _SIMD32_OFFSET(pIn);
  116.       inA2 = _SIMD32_OFFSET(pIn + 2);
  117.  
  118.       /* C = A * scale */
  119.       /* Scale the inputs and then store the 2 results in the destination buffer        
  120.        * in single cycle by packing the outputs */
  121.       out1 = (q31_t) ((q15_t) (inA1 >> 16) * scaleFract);
  122.       out2 = (q31_t) ((q15_t) inA1 * scaleFract);
  123.       out3 = (q31_t) ((q15_t) (inA2 >> 16) * scaleFract);
  124.       out4 = (q31_t) ((q15_t) inA2 * scaleFract);
  125.  
  126.       out1 = out1 >> totShift;
  127.       inA1 = _SIMD32_OFFSET(pIn + 4);
  128.       out2 = out2 >> totShift;
  129.       inA2 = _SIMD32_OFFSET(pIn + 6);
  130.       out3 = out3 >> totShift;
  131.       out4 = out4 >> totShift;
  132.  
  133.       in1 = (q15_t) (__SSAT(out1, 16));
  134.       in2 = (q15_t) (__SSAT(out2, 16));
  135.       in3 = (q15_t) (__SSAT(out3, 16));
  136.       in4 = (q15_t) (__SSAT(out4, 16));
  137.  
  138.       _SIMD32_OFFSET(pOut) = __PKHBT(in2, in1, 16);
  139.       _SIMD32_OFFSET(pOut + 2) = __PKHBT(in4, in3, 16);
  140.  
  141.       /* update pointers to process next sampels */
  142.       pIn += 4u;
  143.       pOut += 4u;
  144.  
  145.  
  146.       /* Decrement the numSamples loop counter */
  147.       blkCnt--;
  148.     }
  149.  
  150.     /* If the numSamples is not a multiple of 4, compute any remaining output samples here.        
  151.      ** No loop unrolling is used. */
  152.     blkCnt = numSamples % 0x4u;
  153.  
  154. #else
  155.  
  156.     /* Run the below code for Cortex-M0 */
  157.  
  158.     /* Initialize blkCnt with number of samples */
  159.     blkCnt = numSamples;
  160.  
  161. #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  162.  
  163.     while(blkCnt > 0u)
  164.     {
  165.       /* C(m,n) = A(m,n) * k */
  166.       /* Scale, saturate and then store the results in the destination buffer. */
  167.       *pOut++ =
  168.         (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
  169.  
  170.       /* Decrement the numSamples loop counter */
  171.       blkCnt--;
  172.     }
  173.     /* Set status as ARM_MATH_SUCCESS */
  174.     status = ARM_MATH_SUCCESS;
  175.   }
  176.  
  177.   /* Return to application */
  178.   return (status);
  179. }
  180.  
  181. /**        
  182.  * @} end of MatrixScale group        
  183.  */
  184.