/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_mult_real_f32.c
* Description: Floating-point complex by real multiplication
*
* $Date: 27. January 2017
* $Revision: V.1.5.1
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "arm_math.h"
/**
* @ingroup groupCmplxMath
*/
/**
* @defgroup CmplxByRealMult Complex-by-Real Multiplication
*
* Multiplies a complex vector by a real 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 while the real array has a total of <code>numSamples</code>
* real values.
*
* The underlying algorithm is used:
*
* <pre>
* for(n=0; n<numSamples; n++) {
* pCmplxDst[(2*n)+0] = pSrcCmplx[(2*n)+0] * pSrcReal[n];
* pCmplxDst[(2*n)+1] = pSrcCmplx[(2*n)+1] * pSrcReal[n];
* }
* </pre>
*
* There are separate functions for floating-point, Q15, and Q31 data types.
*/
/**
* @addtogroup CmplxByRealMult
* @{
*/
/**
* @brief Floating-point complex-by-real multiplication
* @param[in] *pSrcCmplx points to the complex input vector
* @param[in] *pSrcReal points to the real input vector
* @param[out] *pCmplxDst points to the complex output vector
* @param[in] numSamples number of samples in each vector
* @return none.
*/
void arm_cmplx_mult_real_f32(
float32_t * pSrcCmplx,
float32_t * pSrcReal,
float32_t * pCmplxDst,
uint32_t numSamples)
{
float32_t in; /* Temporary variable to store input value */
uint32_t blkCnt; /* loop counters */
#if defined (ARM_MATH_DSP)
/* Run the below code for Cortex-M4 and Cortex-M3 */
float32_t inA1, inA2, inA3, inA4; /* Temporary variables to hold input data */
float32_t inA5, inA6, inA7, inA8; /* Temporary variables to hold input data */
float32_t inB1, inB2, inB3, inB4; /* Temporary variables to hold input data */
float32_t out1, out2, out3, out4; /* Temporary variables to hold output data */
float32_t out5, out6, out7, out8; /* Temporary variables to hold output data */
/* 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[i]. */
/* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
/* read input from complex input buffer */
inA1 = pSrcCmplx[0];
inA2 = pSrcCmplx[1];
/* read input from real input buffer */
inB1 = pSrcReal[0];
/* read input from complex input buffer */
inA3 = pSrcCmplx[2];
/* multiply complex buffer real input with real buffer input */
out1 = inA1 * inB1;
/* read input from complex input buffer */
inA4 = pSrcCmplx[3];
/* multiply complex buffer imaginary input with real buffer input */
out2 = inA2 * inB1;
/* read input from real input buffer */
inB2 = pSrcReal[1];
/* read input from complex input buffer */
inA5 = pSrcCmplx[4];
/* multiply complex buffer real input with real buffer input */
out3 = inA3 * inB2;
/* read input from complex input buffer */
inA6 = pSrcCmplx[5];
/* read input from real input buffer */
inB3 = pSrcReal[2];
/* multiply complex buffer imaginary input with real buffer input */
out4 = inA4 * inB2;
/* read input from complex input buffer */
inA7 = pSrcCmplx[6];
/* multiply complex buffer real input with real buffer input */
out5 = inA5 * inB3;
/* read input from complex input buffer */
inA8 = pSrcCmplx[7];
/* multiply complex buffer imaginary input with real buffer input */
out6 = inA6 * inB3;
/* read input from real input buffer */
inB4 = pSrcReal[3];
/* store result to destination bufer */
pCmplxDst[0] = out1;
/* multiply complex buffer real input with real buffer input */
out7 = inA7 * inB4;
/* store result to destination bufer */
pCmplxDst[1] = out2;
/* multiply complex buffer imaginary input with real buffer input */
out8 = inA8 * inB4;
/* store result to destination bufer */
pCmplxDst[2] = out3;
pCmplxDst[3] = out4;
pCmplxDst[4] = out5;
/* incremnet complex input buffer by 8 to process next samples */
pSrcCmplx += 8U;
/* store result to destination bufer */
pCmplxDst[5] = out6;
/* increment real input buffer by 4 to process next samples */
pSrcReal += 4U;
/* store result to destination bufer */
pCmplxDst[6] = out7;
pCmplxDst[7] = out8;
/* increment destination buffer by 8 to process next sampels */
pCmplxDst += 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 /* #if defined (ARM_MATH_DSP) */
while (blkCnt > 0U)
{
/* C[2 * i] = A[2 * i] * B[i]. */
/* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
in = *pSrcReal++;
/* store the result in the destination buffer. */
*pCmplxDst++ = (*pSrcCmplx++) * (in);
*pCmplxDst++ = (*pSrcCmplx++) * (in);
/* Decrement the numSamples loop counter */
blkCnt--;
}
}
/**
* @} end of CmplxByRealMult group
*/