/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 29. November 2010
* $Revision: V1.0.3
*
* Project: CMSIS DSP Library
* Title: arm_cmplx_mult_cmplx_f32.c
*
* Description: Floating-point complex-by-complex multiplication
*
* 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 CmplxByCmplxMult Complex-by-Complex Multiplication
*
* Multiplies a complex vector by another complex vector and generates a complex result.
* The data in the complex arrays is stored in an interleaved fashion
* (real, imag, real, imag, ...).
* The parameter numSamples
represents the number of complex
* samples processed. The complex arrays have a total of 2*numSamples
* real values.
*
* The underlying algorithm is used:
*
*
* for(n=0; n* * There are separate functions for floating-point, Q15, and Q31 data types. */ /** * @addtogroup CmplxByCmplxMult * @{ */ /** * @brief Floating-point complex-by-complex multiplication * @param[in] *pSrcA points to the first input vector * @param[in] *pSrcB points to the second input vector * @param[out] *pDst points to the output vector * @param[in] numSamples number of complex samples in each vector * @return none. */ void arm_cmplx_mult_cmplx_f32( float32_t * pSrcA, float32_t * pSrcB, float32_t * pDst, uint32_t numSamples) { float32_t a, b, c, d; /* Temporary variables to store real and imaginary values */ uint32_t blkCnt; /* loop counters */ /* 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[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */ /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */ a = *pSrcA++; b = *pSrcA++; c = *pSrcB++; d = *pSrcB++; /* store the result in the destination buffer. */ *pDst++ = (a * c) - (b * d); *pDst++ = (a * d) + (b * c); a = *pSrcA++; b = *pSrcA++; c = *pSrcB++; d = *pSrcB++; *pDst++ = (a * c) - (b * d); *pDst++ = (a * d) + (b * c); a = *pSrcA++; b = *pSrcA++; c = *pSrcB++; d = *pSrcB++; *pDst++ = (a * c) - (b * d); *pDst++ = (a * d) + (b * c); a = *pSrcA++; b = *pSrcA++; c = *pSrcB++; d = *pSrcB++; *pDst++ = (a * c) - (b * d); *pDst++ = (a * d) + (b * c); /* Decrement the numSamples 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[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1]. */ /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i]. */ a = *pSrcA++; b = *pSrcA++; c = *pSrcB++; d = *pSrcB++; /* store the result in the destination buffer. */ *pDst++ = (a * c) - (b * d); *pDst++ = (a * d) + (b * c); /* Decrement the numSamples loop counter */ blkCnt--; } } /** * @} end of CmplxByCmplxMult group */