CMSIS DSP library
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Diff: cmsis_dsp/StatisticsFunctions/arm_power_f32.c
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/StatisticsFunctions/arm_power_f32.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,138 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_power_f32.c +* +* Description: Sum of the squares of the elements of a floating-point vector. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Version 1.1.0 2012/02/15 +* Updated with more optimizations, bug fixes and minor API changes. +* +* Version 1.0.10 2011/7/15 +* Big Endian support added and Merged M0 and M3/M4 Source code. +* +* 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 */ + +#ifndef ARM_MATH_CM0 + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + + /*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; + + +#else + + /* Run the below code for Cortex-M0 */ + + /* Loop over blockSize number of values */ + blkCnt = blockSize; + +#endif /* #ifndef ARM_MATH_CM0 */ + + + 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 + */