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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_dot_prod_f32.c    
  9. *    
  10. * Description:  Floating-point dot product.    
  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 groupMath
  45.  */
  46.  
  47. /**
  48.  * @defgroup dot_prod Vector Dot Product
  49.  *
  50.  * Computes the dot product of two vectors.
  51.  * The vectors are multiplied element-by-element and then summed.
  52.  *
  53.  * <pre>
  54.  *     sum = pSrcA[0]*pSrcB[0] + pSrcA[1]*pSrcB[1] + ... + pSrcA[blockSize-1]*pSrcB[blockSize-1]
  55.  * </pre>    
  56.  *
  57.  * There are separate functions for floating-point, Q7, Q15, and Q31 data types.    
  58.  */
  59.  
  60. /**    
  61.  * @addtogroup dot_prod    
  62.  * @{    
  63.  */
  64.  
  65. /**    
  66.  * @brief Dot product of floating-point vectors.    
  67.  * @param[in]       *pSrcA points to the first input vector    
  68.  * @param[in]       *pSrcB points to the second input vector    
  69.  * @param[in]       blockSize number of samples in each vector    
  70.  * @param[out]      *result output result returned here    
  71.  * @return none.    
  72.  */
  73.  
  74.  
  75. void arm_dot_prod_f32(
  76.   float32_t * pSrcA,
  77.   float32_t * pSrcB,
  78.   uint32_t blockSize,
  79.   float32_t * result)
  80. {
  81.   float32_t sum = 0.0f;                          /* Temporary result storage */
  82.   uint32_t blkCnt;                               /* loop counter */
  83.  
  84.  
  85. #ifndef ARM_MATH_CM0_FAMILY
  86.  
  87. /* Run the below code for Cortex-M4 and Cortex-M3 */
  88.   /*loop Unrolling */
  89.   blkCnt = blockSize >> 2u;
  90.  
  91.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
  92.    ** a second loop below computes the remaining 1 to 3 samples. */
  93.   while(blkCnt > 0u)
  94.   {
  95.     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
  96.     /* Calculate dot product and then store the result in a temporary buffer */
  97.     sum += (*pSrcA++) * (*pSrcB++);
  98.     sum += (*pSrcA++) * (*pSrcB++);
  99.     sum += (*pSrcA++) * (*pSrcB++);
  100.     sum += (*pSrcA++) * (*pSrcB++);
  101.  
  102.     /* Decrement the loop counter */
  103.     blkCnt--;
  104.   }
  105.  
  106.   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.    
  107.    ** No loop unrolling is used. */
  108.   blkCnt = blockSize % 0x4u;
  109.  
  110. #else
  111.  
  112.   /* Run the below code for Cortex-M0 */
  113.  
  114.   /* Initialize blkCnt with number of samples */
  115.   blkCnt = blockSize;
  116.  
  117. #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  118.  
  119.  
  120.   while(blkCnt > 0u)
  121.   {
  122.     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
  123.     /* Calculate dot product and then store the result in a temporary buffer. */
  124.     sum += (*pSrcA++) * (*pSrcB++);
  125.  
  126.     /* Decrement the loop counter */
  127.     blkCnt--;
  128.   }
  129.   /* Store the result back in the destination buffer */
  130.   *result = sum;
  131. }
  132.  
  133. /**    
  134.  * @} end of dot_prod group    
  135.  */
  136.