CMSIS DSP Library from CMSIS 2.0. See http://www.onarm.com/cmsis/ for full details
Dependents: K22F_DSP_Matrix_least_square BNO055-ELEC3810 1BNO055 ECE4180Project--Slave2 ... more
src/Cortex-M4-M3/ComplexMathFunctions/arm_cmplx_mult_cmplx_f32.c
- Committer:
- simon
- Date:
- 2011-03-10
- Revision:
- 0:1014af42efd9
File content as of revision 0:1014af42efd9:
/* ---------------------------------------------------------------------- * 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 <code>numSamples</code> represents the number of complex * samples processed. The complex arrays have a total of <code>2*numSamples</code> * real values. * * The underlying algorithm is used: * * <pre> * for(n=0; n<numSamples; n++) { * pDst[(2*n)+0] = pSrcA[(2*n)+0] * pSrcB[(2*n)+0] - pSrcA[(2*n)+1] * pSrcB[(2*n)+1]; * pDst[(2*n)+1] = pSrcA[(2*n)+0] * pSrcB[(2*n)+1] + pSrcA[(2*n)+1] * pSrcB[(2*n)+0]; * } * </pre> * * 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 */