mbed-os 6.10 versione
cmsis_dsp/ComplexMathFunctions/arm_cmplx_mag_squared_f32.c
- Committer:
- emilmont
- Date:
- 2012-11-28
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
File content as of revision 1:fdd22bb7aa52:
/* ---------------------------------------------------------------------- * Copyright (C) 2010 ARM Limited. All rights reserved. * * $Date: 15. February 2012 * $Revision: V1.1.0 * * Project: CMSIS DSP Library * Title: arm_cmplx_mag_squared_f32.c * * Description: Floating-point complex magnitude squared. * * 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. * ---------------------------------------------------------------------------- */ #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 <code>pSrc</code> points to the source data and * <code>pDst</code> points to the where the result should be written. * <code>numSamples</code> 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 <code>2*numSamples</code> values; * the output array has a total of <code>numSamples</code> values. * * The underlying algorithm is used: * * <pre> * for(n=0; n<numSamples; n++) { * pDst[n] = pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2; * } * </pre> * * 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 */ #ifndef ARM_MATH_CM0 float32_t real1, real2, real3, real4; /* Temporary variables to hold real values */ float32_t imag1, imag2, imag3, imag4; /* Temporary variables to hold imaginary values */ float32_t mul1, mul2, mul3, mul4; /* Temporary variables */ float32_t mul5, mul6, mul7, mul8; /* Temporary variables */ float32_t out1, out2, out3, out4; /* Temporary variables to hold output values */ /*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]) */ /* read real input sample from source buffer */ real1 = pSrc[0]; /* read imaginary input sample from source buffer */ imag1 = pSrc[1]; /* calculate power of real value */ mul1 = real1 * real1; /* read real input sample from source buffer */ real2 = pSrc[2]; /* calculate power of imaginary value */ mul2 = imag1 * imag1; /* read imaginary input sample from source buffer */ imag2 = pSrc[3]; /* calculate power of real value */ mul3 = real2 * real2; /* read real input sample from source buffer */ real3 = pSrc[4]; /* calculate power of imaginary value */ mul4 = imag2 * imag2; /* read imaginary input sample from source buffer */ imag3 = pSrc[5]; /* calculate power of real value */ mul5 = real3 * real3; /* calculate power of imaginary value */ mul6 = imag3 * imag3; /* read real input sample from source buffer */ real4 = pSrc[6]; /* accumulate real and imaginary powers */ out1 = mul1 + mul2; /* read imaginary input sample from source buffer */ imag4 = pSrc[7]; /* accumulate real and imaginary powers */ out2 = mul3 + mul4; /* calculate power of real value */ mul7 = real4 * real4; /* calculate power of imaginary value */ mul8 = imag4 * imag4; /* store output to destination */ pDst[0] = out1; /* accumulate real and imaginary powers */ out3 = mul5 + mul6; /* store output to destination */ pDst[1] = out2; /* accumulate real and imaginary powers */ out4 = mul7 + mul8; /* store output to destination */ pDst[2] = out3; /* increment destination pointer by 8 to process next samples */ pSrc += 8u; /* store output to destination */ pDst[3] = out4; /* increment destination pointer by 4 to process next samples */ pDst += 4u; /* 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; #else /* Run the below code for Cortex-M0 */ blkCnt = numSamples; #endif /* #ifndef ARM_MATH_CM0 */ while(blkCnt > 0u) { /* C[0] = (A[0] * A[0] + A[1] * A[1]) */ real = *pSrc++; imag = *pSrc++; /* out = (real * real) + (imag * imag) */ /* store the result in the destination buffer. */ *pDst++ = (real * real) + (imag * imag); /* Decrement the loop counter */ blkCnt--; } } /** * @} end of cmplx_mag_squared group */