/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 29. November 2010
* $Revision: V1.0.3
*
* Project: CMSIS DSP Library
* Title: arm_cmplx_mag_squared_f32.c
*
* Description: Floating-point complex magnitude squared.
*
* 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.
* ---------------------------------------------------------------------------- */
#include "arm_math.h"
/**
* @ingroup groupCmplxMath
*/
/**
* @defgroup cmplx_mag_squared Complex Magnitude Squared
*
* Computes the magnitude squared of the elements of a complex data vector.
*
* The pSrc
points to the source data and
* pDst
points to the where the result should be written.
* numSamples
specifies the number of complex samples
* in the input array and the data is stored in an interleaved fashion
* (real, imag, real, imag, ...).
* The input array has a total of 2*numSamples
values;
* the output array has a total of numSamples
values.
*
* The underlying algorithm is used:
*
*
* for(n=0; n* * There are separate functions for floating-point, Q15, and Q31 data types. */ /** * @addtogroup cmplx_mag_squared * @{ */ /** * @brief Floating-point complex magnitude squared * @param[in] *pSrc points to the complex input vector * @param[out] *pDst points to the real output vector * @param[in] numSamples number of complex samples in the input vector * @return none. */ void arm_cmplx_mag_squared_f32( float32_t * pSrc, float32_t * pDst, uint32_t numSamples) { float32_t real, imag; /* Temporary variables to store real and imaginary values */ uint32_t blkCnt; /* loop counter */ /*loop Unrolling */ blkCnt = numSamples >> 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[0] = (A[0] * A[0] + A[1] * A[1]) */ real = *pSrc++; imag = *pSrc++; /* store the result in the destination buffer. */ *pDst++ = (real * real) + (imag * imag); real = *pSrc++; imag = *pSrc++; *pDst++ = (real * real) + (imag * imag); real = *pSrc++; imag = *pSrc++; *pDst++ = (real * real) + (imag * imag); real = *pSrc++; imag = *pSrc++; *pDst++ = (real * real) + (imag * imag); /* Decrement the loop counter */ blkCnt--; } /* If the numSamples is not a multiple of 4, compute any remaining output samples here. ** No loop unrolling is used. */ blkCnt = numSamples % 0x4u; while(blkCnt > 0u) { /* C[0] = (A[0] * A[0] + A[1] * A[1]) */ real = *pSrc++; imag = *pSrc++; /* store the result in the destination buffer. */ *pDst++ = (real * real) + (imag * imag); /* Decrement the loop counter */ blkCnt--; } } /** * @} end of cmplx_mag_squared group */