CMSIS DSP Software Library: arm_power_f32.c Source File

- Main Page
- Modules
- Data Structures
- Files
- Examples

- File List
- Globals

# arm_power_f32.c

Go to the documentation of this file.

    00001 /* ----------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        15. July 2011
    00005 * $Revision:    V1.0.10
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_power_f32.c
    00009 *
    00010 * Description:  Sum of the squares of the elements of a floating-point vector.
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
    00013 *
    00014 * Version 1.0.10 2011/7/15
    00015 *    Big Endian support added and Merged M0 and M3/M4 Source code.
    00016 *
    00017 * Version 1.0.3 2010/11/29
    00018 *    Re-organized the CMSIS folders and updated documentation.
    00019 *
    00020 * Version 1.0.2 2010/11/11
    00021 *    Documentation updated.
    00022 *
    00023 * Version 1.0.1 2010/10/05
    00024 *    Production release and review comments incorporated.
    00025 *
    00026 * Version 1.0.0 2010/09/20
    00027 *    Production release and review comments incorporated.
    00028 *
    00029 * Version 0.0.7  2010/06/10
    00030 *    Misra-C changes done
    00031 * ---------------------------------------------------------------------------- */
    00032
    00033 #include "arm_math.h"
    00034
    00068 void arm_power_f32(
    00069   float32_t * pSrc,
    00070   uint32_t blockSize,
    00071   float32_t * pResult)
    00072 {
    00073   float32_t sum = 0.0f;                          /* accumulator */
    00074   float32_t in;                                  /* Temporary variable to store input value */
    00075   uint32_t blkCnt;                               /* loop counter */
    00076
    00077 #ifndef ARM_MATH_CM0
    00078
    00079   /* Run the below code for Cortex-M4 and Cortex-M3 */
    00080
    00081   /*loop Unrolling */
    00082   blkCnt = blockSize >> 2u;
    00083
    00084   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00085    ** a second loop below computes the remaining 1 to 3 samples. */
    00086   while(blkCnt > 0u)
    00087   {
    00088     /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
    00089     /* Compute Power and then store the result in a temporary variable, sum. */
    00090     in = *pSrc++;
    00091     sum += in * in;
    00092     in = *pSrc++;
    00093     sum += in * in;
    00094     in = *pSrc++;
    00095     sum += in * in;
    00096     in = *pSrc++;
    00097     sum += in * in;
    00098
    00099     /* Decrement the loop counter */
    00100     blkCnt--;
    00101   }
    00102
    00103   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
    00104    ** No loop unrolling is used. */
    00105   blkCnt = blockSize % 0x4u;
    00106
    00107
    00108 #else
    00109
    00110   /* Run the below code for Cortex-M0 */
    00111
    00112   /* Loop over blockSize number of values */
    00113   blkCnt = blockSize;
    00114
    00115 #endif /* #ifndef ARM_MATH_CM0 */
    00116
    00117
    00118   while(blkCnt > 0u)
    00119   {
    00120     /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
    00121     /* compute power and then store the result in a temporary variable, sum. */
    00122     in = *pSrc++;
    00123     sum += in * in;
    00124
    00125     /* Decrement the loop counter */
    00126     blkCnt--;
    00127   }
    00128
    00129   /* Store the result to the destination */
    00130   *pResult = sum;
    00131 }
    00132

All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Defines