/* ----------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date: 16/10/14 6:01p $Revision:  V.1.4.5
*
* Project:      CMSIS DSP Library
* Title:        arm_cmplx_mult_real_f32.c
*
* Description:  Floating-point complex by real multiplication
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
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*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* -------------------------------------------------------------------- */

#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 */

#ifndef ARM_MATH_CM0_FAMILY

    /* 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 /* #ifndef ARM_MATH_CM0_FAMILY */

    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
 */
