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# arm_power_f32.c

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    00001 /* ----------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        29. November 2010
    00005 * $Revision:    V1.0.3
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_power_f32.c
    00009 *
    00010 * Description:  sum of the square of the elements in a floating point array
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3
    00013 *
    00014 * Version 1.0.3 2010/11/29
    00015 *    Re-organized the CMSIS folders and updated documentation.
    00016 *
    00017 * Version 1.0.2 2010/11/11
    00018 *    Documentation updated.
    00019 *
    00020 * Version 1.0.1 2010/10/05
    00021 *    Production release and review comments incorporated.
    00022 *
    00023 * Version 1.0.0 2010/09/20
    00024 *    Production release and review comments incorporated.
    00025 *
    00026 * Version 0.0.7  2010/06/10
    00027 *    Misra-C changes done
    00028 * ---------------------------------------------------------------------------- */
    00029
    00030 #include "arm_math.h"
    00031
    00065 void arm_power_f32(
    00066   float32_t * pSrc,
    00067   uint32_t blockSize,
    00068   float32_t * pResult)
    00069 {
    00070   float32_t sum = 0.0f;                          /* accumulator */
    00071   float32_t in;                                  /* Temporary variable to store input value */
    00072   uint32_t blkCnt;                               /* loop counter */
    00073
    00074   /*loop Unrolling */
    00075   blkCnt = blockSize >> 2u;
    00076
    00077   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00078    ** a second loop below computes the remaining 1 to 3 samples. */
    00079   while(blkCnt > 0u)
    00080   {
    00081     /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
    00082     /* Compute Power and then store the result in a temporary variable, sum. */
    00083     in = *pSrc++;
    00084     sum += in * in;
    00085     in = *pSrc++;
    00086     sum += in * in;
    00087     in = *pSrc++;
    00088     sum += in * in;
    00089     in = *pSrc++;
    00090     sum += in * in;
    00091
    00092     /* Decrement the loop counter */
    00093     blkCnt--;
    00094   }
    00095
    00096   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
    00097    ** No loop unrolling is used. */
    00098   blkCnt = blockSize % 0x4u;
    00099
    00100   while(blkCnt > 0u)
    00101   {
    00102     /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
    00103     /* compute power and then store the result in a temporary variable, sum. */
    00104     in = *pSrc++;
    00105     sum += in * in;
    00106
    00107     /* Decrement the loop counter */
    00108     blkCnt--;
    00109   }
    00110
    00111   /* Store the result to the destination */
    00112   *pResult = sum;
    00113 }
    00114

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