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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_f32.c    
  9. *    
  10. * Description:  Multiplies a floating-point 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.  * @defgroup MatrixScale Matrix Scale        
  49.  *        
  50.  * Multiplies a matrix by a scalar.  This is accomplished by multiplying each element in the        
  51.  * matrix by the scalar.  For example:        
  52.  * \image html MatrixScale.gif "Matrix Scaling of a 3 x 3 matrix"        
  53.  *        
  54.  * The function checks to make sure that the input and output matrices are of the same size.        
  55.  *        
  56.  * In the fixed-point Q15 and Q31 functions, <code>scale</code> is represented by        
  57.  * a fractional multiplication <code>scaleFract</code> and an arithmetic shift <code>shift</code>.        
  58.  * The shift allows the gain of the scaling operation to exceed 1.0.        
  59.  * The overall scale factor applied to the fixed-point data is        
  60.  * <pre>        
  61.  *     scale = scaleFract * 2^shift.        
  62.  * </pre>        
  63.  */
  64.  
  65. /**        
  66.  * @addtogroup MatrixScale        
  67.  * @{        
  68.  */
  69.  
  70. /**        
  71.  * @brief Floating-point matrix scaling.        
  72.  * @param[in]       *pSrc points to input matrix structure        
  73.  * @param[in]       scale scale factor to be applied        
  74.  * @param[out]      *pDst points to output matrix structure        
  75.  * @return              The function returns either <code>ARM_MATH_SIZE_MISMATCH</code>        
  76.  * or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.        
  77.  *        
  78.  */
  79.  
  80. arm_status arm_mat_scale_f32(
  81.   const arm_matrix_instance_f32 * pSrc,
  82.   float32_t scale,
  83.   arm_matrix_instance_f32 * pDst)
  84. {
  85.   float32_t *pIn = pSrc->pData;                  /* input data matrix pointer */
  86.   float32_t *pOut = pDst->pData;                 /* output data matrix pointer */
  87.   uint32_t numSamples;                           /* total number of elements in the matrix */
  88.   uint32_t blkCnt;                               /* loop counters */
  89.   arm_status status;                             /* status of matrix scaling     */
  90.  
  91. #ifndef ARM_MATH_CM0_FAMILY
  92.  
  93.   float32_t in1, in2, in3, in4;                  /* temporary variables */
  94.   float32_t out1, out2, out3, out4;              /* temporary variables */
  95.  
  96. #endif //      #ifndef ARM_MATH_CM0_FAMILY
  97.  
  98. #ifdef ARM_MATH_MATRIX_CHECK
  99.   /* Check for matrix mismatch condition */
  100.   if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
  101.   {
  102.     /* Set status as ARM_MATH_SIZE_MISMATCH */
  103.     status = ARM_MATH_SIZE_MISMATCH;
  104.   }
  105.   else
  106. #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
  107.   {
  108.     /* Total number of samples in the input matrix */
  109.     numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
  110.  
  111. #ifndef ARM_MATH_CM0_FAMILY
  112.  
  113.     /* Run the below code for Cortex-M4 and Cortex-M3 */
  114.  
  115.     /* Loop Unrolling */
  116.     blkCnt = numSamples >> 2;
  117.  
  118.     /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
  119.      ** a second loop below computes the remaining 1 to 3 samples. */
  120.     while(blkCnt > 0u)
  121.     {
  122.       /* C(m,n) = A(m,n) * scale */
  123.       /* Scaling and results are stored in the destination buffer. */
  124.       in1 = pIn[0];
  125.       in2 = pIn[1];
  126.       in3 = pIn[2];
  127.       in4 = pIn[3];
  128.  
  129.       out1 = in1 * scale;
  130.       out2 = in2 * scale;
  131.       out3 = in3 * scale;
  132.       out4 = in4 * scale;
  133.  
  134.  
  135.       pOut[0] = out1;
  136.       pOut[1] = out2;
  137.       pOut[2] = out3;
  138.       pOut[3] = out4;
  139.  
  140.       /* update pointers to process next sampels */
  141.       pIn += 4u;
  142.       pOut += 4u;
  143.  
  144.       /* Decrement the numSamples loop counter */
  145.       blkCnt--;
  146.     }
  147.  
  148.     /* If the numSamples is not a multiple of 4, compute any remaining output samples here.    
  149.      ** No loop unrolling is used. */
  150.     blkCnt = numSamples % 0x4u;
  151.  
  152. #else
  153.  
  154.     /* Run the below code for Cortex-M0 */
  155.  
  156.     /* Initialize blkCnt with number of samples */
  157.     blkCnt = numSamples;
  158.  
  159. #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  160.  
  161.     while(blkCnt > 0u)
  162.     {
  163.       /* C(m,n) = A(m,n) * scale */
  164.       /* The results are stored in the destination buffer. */
  165.       *pOut++ = (*pIn++) * scale;
  166.  
  167.       /* Decrement the loop counter */
  168.       blkCnt--;
  169.     }
  170.  
  171.     /* Set status as ARM_MATH_SUCCESS */
  172.     status = ARM_MATH_SUCCESS;
  173.   }
  174.  
  175.   /* Return to application */
  176.   return (status);
  177. }
  178.  
  179. /**        
  180.  * @} end of MatrixScale group        
  181.  */
  182.