CMSIS DSP library
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Diff: cmsis_dsp/ComplexMathFunctions/arm_cmplx_conj_f32.c
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/ComplexMathFunctions/arm_cmplx_conj_f32.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,174 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_cmplx_conj_f32.c +* +* Description: Floating-point complex conjugate. +* +* 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_conj Complex Conjugate + * + * Conjugates 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 + * and the data in each array is stored in an interleaved fashion + * (real, imag, real, imag, ...). + * Each array has a total of <code>2*numSamples</code> values. + * The underlying algorithm is used: + * + * <pre> + * for(n=0; n<numSamples; n++) { + * pDst[(2*n)+0)] = pSrc[(2*n)+0]; // real part + * pDst[(2*n)+1)] = -pSrc[(2*n)+1]; // imag part + * } + * </pre> + * + * There are separate functions for floating-point, Q15, and Q31 data types. + */ + +/** + * @addtogroup cmplx_conj + * @{ + */ + +/** + * @brief Floating-point complex conjugate. + * @param *pSrc points to the input vector + * @param *pDst points to the output vector + * @param numSamples number of complex samples in each vector + * @return none. + */ + +void arm_cmplx_conj_f32( + float32_t * pSrc, + float32_t * pDst, + uint32_t numSamples) +{ + uint32_t blkCnt; /* loop counter */ + +#ifndef ARM_MATH_CM0 + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + float32_t inR1, inR2, inR3, inR4; + float32_t inI1, inI2, inI3, inI4; + + /*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]+jC[1] = A[0]+ j (-1) A[1] */ + /* Calculate Complex Conjugate and then store the results in the destination buffer. */ + /* read real input samples */ + inR1 = pSrc[0]; + /* store real samples to destination */ + pDst[0] = inR1; + inR2 = pSrc[2]; + pDst[2] = inR2; + inR3 = pSrc[4]; + pDst[4] = inR3; + inR4 = pSrc[6]; + pDst[6] = inR4; + + /* read imaginary input samples */ + inI1 = pSrc[1]; + inI2 = pSrc[3]; + + /* conjugate input */ + inI1 = -inI1; + + /* read imaginary input samples */ + inI3 = pSrc[5]; + + /* conjugate input */ + inI2 = -inI2; + + /* read imaginary input samples */ + inI4 = pSrc[7]; + + /* conjugate input */ + inI3 = -inI3; + + /* store imaginary samples to destination */ + pDst[1] = inI1; + pDst[3] = inI2; + + /* conjugate input */ + inI4 = -inI4; + + /* store imaginary samples to destination */ + pDst[5] = inI3; + + /* increment source pointer by 8 to process next sampels */ + pSrc += 8u; + + /* store imaginary sample to destination */ + pDst[7] = inI4; + + /* increment destination pointer by 8 to store next samples */ + pDst += 8u; + + /* 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) + { + /* realOut + j (imagOut) = realIn + j (-1) imagIn */ + /* Calculate Complex Conjugate and then store the results in the destination buffer. */ + *pDst++ = *pSrc++; + *pDst++ = -*pSrc++; + + /* Decrement the loop counter */ + blkCnt--; + } +} + +/** + * @} end of cmplx_conj group + */