text: /* ----------------------------------------------------------------------  
  * Copyright (C) 2010 ARM Limited. All rights reserved.  
  *  
  * $Date:        29. November 2010  
  * $Revision: 	V1.0.3  
  *  
  * Project: 	    CMSIS DSP Library  
  * Title:		arm_power_f32.c  
  *  
  * Description:	sum of the square of the elements in a floating point array  
  *  
  * Target Processor: Cortex-M4/Cortex-M3
  *  
  * Version 1.0.3 2010/11/29 
  *    Re-organized the CMSIS folders and updated documentation.  
  *   
  * Version 1.0.2 2010/11/11  
  *    Documentation updated.   
  *  
  * Version 1.0.1 2010/10/05   
  *    Production release and review comments incorporated.  
  *  
  * Version 1.0.0 2010/09/20   
  *    Production release and review comments incorporated.  
  *  
  * Version 0.0.7  2010/06/10   
  *    Misra-C changes done  
  * ---------------------------------------------------------------------------- */ 
   
  #include "arm_math.h" 
   
  /**  
   * @ingroup groupStats  
   */ 
   
  /**  
   * @defgroup power Power  
   *  
   * Calculates the sum of the squares of the elements in the input vector.  
   * The underlying algorithm is used:  
   *  
   * <pre>  
   * 	Result = pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + pSrc[2] * pSrc[2] + ... + pSrc[blockSize-1] * pSrc[blockSize-1];  
   * </pre>  
   * 
   * There are separate functions for floating point, Q31, Q15, and Q7 data types.   
   */ 
   
  /**  
   * @addtogroup power  
   * @{  
   */ 
   
   
  /**  
   * @brief Sum of the squares of the elements of a floating-point vector.  
   * @param[in]       *pSrc points to the input vector  
   * @param[in]       blockSize length of the input vector  
   * @param[out]      *pResult sum of the squares value returned here  
   * @return none.  
   *  
   */ 
   
   
  void arm_power_f32( 
    float32_t * pSrc, 
    uint32_t blockSize, 
    float32_t * pResult) 
  { 
    float32_t sum = 0.0f;                          /* accumulator */ 
    float32_t in;                                  /* Temporary variable to store input value */ 
    uint32_t blkCnt;                               /* loop counter */ 
   
    /*loop Unrolling */ 
    blkCnt = blockSize >> 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 = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */ 
      /* Compute Power and then store the result in a temporary variable, sum. */ 
      in = *pSrc++; 
      sum += in * in; 
      in = *pSrc++; 
      sum += in * in; 
      in = *pSrc++; 
      sum += in * in; 
      in = *pSrc++; 
      sum += in * in; 
   
      /* Decrement the loop counter */ 
      blkCnt--; 
    } 
   
    /* If the blockSize is not a multiple of 4, compute any remaining output samples here.  
     ** No loop unrolling is used. */ 
    blkCnt = blockSize % 0x4u; 
   
    while(blkCnt > 0u) 
    { 
      /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */ 
      /* compute power and then store the result in a temporary variable, sum. */ 
      in = *pSrc++; 
      sum += in * in; 
   
      /* Decrement the loop counter */ 
      blkCnt--; 
    } 
   
    /* Store the result to the destination */ 
    *pResult = sum; 
  } 
   
  /**  
   * @} end of power group  
   */ 
  