/*!
 * \file volk_gnsssdr_8ic_s8ic_multiply_8ic.h
 * \brief VOLK_GNSSSDR kernel: multiplies a group of 16 bits vectors by one constant vector.
 * \authors <ul>
 *          <li> Andres Cecilia, 2014. a.cecilia.luque(at)gmail.com
 *          </ul>
 *
 * VOLK_GNSSSDR kernel that multiplies a group of 16 bits vectors
 * (8 bits the real part and 8 bits the imaginary part) by one constant vector
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2010-2019  (see AUTHORS file for a list of contributors)
 *
 * GNSS-SDR is a software defined Global Navigation
 *          Satellite Systems receiver
 *
 * This file is part of GNSS-SDR.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * -------------------------------------------------------------------------
 */

/*!
 * \page volk_gnsssdr_8ic_s8ic_multiply_8ic
 *
 * \b Overview
 *
 * Multiplies the input vector by a scalar and stores the results in the third vector
 *
 * <b>Dispatcher Prototype</b>
 * \code
 * void volk_gnsssdr_8ic_s8ic_multiply_8ic(lv_8sc_t* cVector, const lv_8sc_t* aVector, const lv_8sc_t scalar, unsigned int num_points);
 * \endcode
 *
 * \b Inputs
 * \li aVector: The vector to be multiplied.
 * \li scalar The complex scalar to multiply \p aVector
 * \li num_points: The number of complex values in \p aVector to be multiplied by \p scalar and stored into \p cVector.
 *
 * \b Outputs
 * \li cVector: The vector where the results will be stored
 *
 */

#ifndef INCLUDED_volk_gnsssdr_8ic_s8ic_multiply_8ic_H
#define INCLUDED_volk_gnsssdr_8ic_s8ic_multiply_8ic_H

#include <volk_gnsssdr/volk_gnsssdr_complex.h>

#ifdef LV_HAVE_SSE3
#include <pmmintrin.h>

static inline void volk_gnsssdr_8ic_s8ic_multiply_8ic_u_sse3(lv_8sc_t* cVector, const lv_8sc_t* aVector, const lv_8sc_t scalar, unsigned int num_points)
{
    unsigned int number = 0;
    const unsigned int sse_iters = num_points / 8;

    __m128i x, y, mult1, realx, imagx, realy, imagy, realx_mult_realy, imagx_mult_imagy, realx_mult_imagy, imagx_mult_realy, realc, imagc, totalc;

    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;

    mult1 = _mm_set_epi8(0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF);

    y = _mm_set1_epi16(*(short*)&scalar);
    imagy = _mm_srli_si128(y, 1);
    imagy = _mm_and_si128(imagy, mult1);
    realy = _mm_and_si128(y, mult1);

    for (; number < sse_iters; number++)
        {
            x = _mm_lddqu_si128((__m128i*)a);

            imagx = _mm_srli_si128(x, 1);
            imagx = _mm_and_si128(imagx, mult1);
            realx = _mm_and_si128(x, mult1);

            realx_mult_realy = _mm_mullo_epi16(realx, realy);
            imagx_mult_imagy = _mm_mullo_epi16(imagx, imagy);
            realx_mult_imagy = _mm_mullo_epi16(realx, imagy);
            imagx_mult_realy = _mm_mullo_epi16(imagx, realy);

            realc = _mm_sub_epi16(realx_mult_realy, imagx_mult_imagy);
            realc = _mm_and_si128(realc, mult1);
            imagc = _mm_add_epi16(realx_mult_imagy, imagx_mult_realy);
            imagc = _mm_and_si128(imagc, mult1);
            imagc = _mm_slli_si128(imagc, 1);

            totalc = _mm_or_si128(realc, imagc);

            _mm_storeu_si128((__m128i*)c, totalc);

            a += 8;
            c += 8;
        }

    for (number = sse_iters * 8; number < num_points; ++number)
        {
            *c++ = (*a++) * scalar;
        }
}
#endif /* LV_HAVE_SSE3 */


#ifdef LV_HAVE_GENERIC

static inline void volk_gnsssdr_8ic_s8ic_multiply_8ic_generic(lv_8sc_t* cVector, const lv_8sc_t* aVector, const lv_8sc_t scalar, unsigned int num_points)
{
    /*lv_8sc_t* cPtr = cVector;
     const lv_8sc_t* aPtr = aVector;

     for (int i = 0; i<num_points; ++i)
     {
     *cPtr++ = (*aPtr++) * scalar;
     }*/

    lv_8sc_t* cPtr = cVector;
    const lv_8sc_t* aPtr = aVector;
    unsigned int number = num_points;

    // unwrap loop
    while (number >= 8)
        {
            *cPtr++ = (*aPtr++) * scalar;
            *cPtr++ = (*aPtr++) * scalar;
            *cPtr++ = (*aPtr++) * scalar;
            *cPtr++ = (*aPtr++) * scalar;
            *cPtr++ = (*aPtr++) * scalar;
            *cPtr++ = (*aPtr++) * scalar;
            *cPtr++ = (*aPtr++) * scalar;
            *cPtr++ = (*aPtr++) * scalar;
            number -= 8;
        }

    // clean up any remaining
    while (number-- > 0)
        *cPtr++ = *aPtr++ * scalar;
}
#endif /* LV_HAVE_GENERIC */


#ifdef LV_HAVE_SSE3
#include <pmmintrin.h>

static inline void volk_gnsssdr_8ic_s8ic_multiply_8ic_a_sse3(lv_8sc_t* cVector, const lv_8sc_t* aVector, const lv_8sc_t scalar, unsigned int num_points)
{
    unsigned int number = 0;
    const unsigned int sse_iters = num_points / 8;

    __m128i x, y, mult1, realx, imagx, realy, imagy, realx_mult_realy, imagx_mult_imagy, realx_mult_imagy, imagx_mult_realy, realc, imagc, totalc;

    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;

    mult1 = _mm_set_epi8(0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF);

    y = _mm_set1_epi16(*(short*)&scalar);
    imagy = _mm_srli_si128(y, 1);
    imagy = _mm_and_si128(imagy, mult1);
    realy = _mm_and_si128(y, mult1);

    for (; number < sse_iters; number++)
        {
            x = _mm_load_si128((__m128i*)a);

            imagx = _mm_srli_si128(x, 1);
            imagx = _mm_and_si128(imagx, mult1);
            realx = _mm_and_si128(x, mult1);

            realx_mult_realy = _mm_mullo_epi16(realx, realy);
            imagx_mult_imagy = _mm_mullo_epi16(imagx, imagy);
            realx_mult_imagy = _mm_mullo_epi16(realx, imagy);
            imagx_mult_realy = _mm_mullo_epi16(imagx, realy);

            realc = _mm_sub_epi16(realx_mult_realy, imagx_mult_imagy);
            realc = _mm_and_si128(realc, mult1);
            imagc = _mm_add_epi16(realx_mult_imagy, imagx_mult_realy);
            imagc = _mm_and_si128(imagc, mult1);
            imagc = _mm_slli_si128(imagc, 1);

            totalc = _mm_or_si128(realc, imagc);

            _mm_store_si128((__m128i*)c, totalc);

            a += 8;
            c += 8;
        }

    for (number = sse_iters * 8; number < num_points; ++number)
        {
            *c++ = (*a++) * scalar;
        }
}
#endif /* LV_HAVE_SSE3 */


#ifdef LV_HAVE_ORC

extern void volk_gnsssdr_8ic_s8ic_multiply_8ic_a_orc_impl(lv_8sc_t* cVector, const lv_8sc_t* aVector, const char scalarreal, const char scalarimag, unsigned int num_points);
static inline void volk_gnsssdr_8ic_s8ic_multiply_8ic_u_orc(lv_8sc_t* cVector, const lv_8sc_t* aVector, const lv_8sc_t scalar, unsigned int num_points)
{
    volk_gnsssdr_8ic_s8ic_multiply_8ic_a_orc_impl(cVector, aVector, lv_creal(scalar), lv_cimag(scalar), num_points);
}
#endif /* LV_HAVE_ORC */

#endif /* INCLUDED_volk_gnsssdr_32fc_x2_multiply_32fc_H */
