/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 15. February 2012
* $Revision: V1.1.0
*
* Project: CMSIS DSP Library
* Title: arm_cmplx_mult_cmplx_f32.c
*
* Description: Floating-point complex-by-complex multiplication
*
* 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 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 a1, b1, c1, d1; /* Temporary variables to store real and imaginary values */ uint32_t blkCnt; /* loop counters */ #ifndef ARM_MATH_CM0 /* Run the below code for Cortex-M4 and Cortex-M3 */ float32_t a2, b2, c2, d2; /* Temporary variables to store real and imaginary values */ float32_t acc1, acc2, acc3, acc4; /* 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]. */ a1 = *pSrcA; /* A[2 * i] */ c1 = *pSrcB; /* B[2 * i] */ b1 = *(pSrcA + 1); /* A[2 * i + 1] */ acc1 = a1 * c1; /* acc1 = A[2 * i] * B[2 * i] */ a2 = *(pSrcA + 2); /* A[2 * i + 2] */ acc2 = (b1 * c1); /* acc2 = A[2 * i + 1] * B[2 * i] */ d1 = *(pSrcB + 1); /* B[2 * i + 1] */ c2 = *(pSrcB + 2); /* B[2 * i + 2] */ acc1 -= b1 * d1; /* acc1 = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1] */ d2 = *(pSrcB + 3); /* B[2 * i + 3] */ acc3 = a2 * c2; /* acc3 = A[2 * i + 2] * B[2 * i + 2] */ b2 = *(pSrcA + 3); /* A[2 * i + 3] */ acc2 += (a1 * d1); /* acc2 = A[2 * i + 1] * B[2 * i] + A[2 * i] * B[2 * i + 1] */ a1 = *(pSrcA + 4); /* A[2 * i + 4] */ acc4 = (a2 * d2); /* acc4 = A[2 * i + 2] * B[2 * i + 3] */ c1 = *(pSrcB + 4); /* B[2 * i + 4] */ acc3 -= (b2 * d2); /* acc3 = A[2 * i + 2] * B[2 * i + 2] - A[2 * i + 3] * B[2 * i + 3] */ *pDst = acc1; /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1] */ b1 = *(pSrcA + 5); /* A[2 * i + 5] */ acc4 += b2 * c2; /* acc4 = A[2 * i + 2] * B[2 * i + 3] + A[2 * i + 3] * B[2 * i + 2] */ *(pDst + 1) = acc2; /* C[2 * i + 1] = A[2 * i + 1] * B[2 * i] + A[2 * i] * B[2 * i + 1] */ acc1 = (a1 * c1); d1 = *(pSrcB + 5); acc2 = (b1 * c1); *(pDst + 2) = acc3; *(pDst + 3) = acc4; a2 = *(pSrcA + 6); acc1 -= (b1 * d1); c2 = *(pSrcB + 6); acc2 += (a1 * d1); b2 = *(pSrcA + 7); acc3 = (a2 * c2); d2 = *(pSrcB + 7); acc4 = (b2 * c2); *(pDst + 4) = acc1; pSrcA += 8u; acc3 -= (b2 * d2); acc4 += (a2 * d2); *(pDst + 5) = acc2; pSrcB += 8u; *(pDst + 6) = acc3; *(pDst + 7) = acc4; pDst += 8u; /* 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; #else /* Run the below code for Cortex-M0 */ blkCnt = numSamples; #endif /* #ifndef ARM_MATH_CM0 */ 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]. */ a1 = *pSrcA++; b1 = *pSrcA++; c1 = *pSrcB++; d1 = *pSrcB++; /* store the result in the destination buffer. */ *pDst++ = (a1 * c1) - (b1 * d1); *pDst++ = (a1 * d1) + (b1 * c1); /* Decrement the numSamples loop counter */ blkCnt--; } } /** * @} end of CmplxByCmplxMult group */