/* -*- c++ -*- */
/*
 * Copyright 2012, 2014 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 *
 * GNU Radio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

/*!
 * \page volk_8ic_x2_s32f_multiply_conjugate_32fc
 *
 * \b Overview
 *
 * Multiplys the one complex vector with the complex conjugate of the
 * second complex vector and stores their results in the third vector
 *
 * <b>Dispatcher Prototype</b>
 * \code
 * void volk_8ic_x2_s32f_multiply_conjugate_32fc(lv_32fc_t* cVector, const lv_8sc_t* aVector, const lv_8sc_t* bVector, const float scalar, unsigned int num_points)
 * \endcode
 *
 * \b Inputs
 * \li aVector: One of the complex vectors to be multiplied.
 * \li bVector: The complex vector which will be converted to complex conjugate and multiplied.
 * \li scalar: each output value is scaled by 1/scalar.
 * \li num_points: The number of complex values in aVector and bVector to be multiplied together and stored into cVector.
 *
 * \b Outputs
 * \li cVector: The complex vector where the results will be stored.
 *
 * \b Example
 * \code
 * int N = 10000;
 *
 * <FIXME>
 *
 * volk_8ic_x2_s32f_multiply_conjugate_32fc();
 *
 * \endcode
 */

#ifndef INCLUDED_volk_8ic_x2_s32f_multiply_conjugate_32fc_a_H
#define INCLUDED_volk_8ic_x2_s32f_multiply_conjugate_32fc_a_H

#include <inttypes.h>
#include <stdio.h>
#include <volk/volk_complex.h>

#ifdef LV_HAVE_SSE4_1
#include <smmintrin.h>

static inline void
volk_8ic_x2_s32f_multiply_conjugate_32fc_a_sse4_1(lv_32fc_t* cVector, const lv_8sc_t* aVector,
                                                  const lv_8sc_t* bVector, const float scalar,
                                                  unsigned int num_points)
{
  unsigned int number = 0;
  const unsigned int quarterPoints = num_points / 4;

  __m128i x, y, realz, imagz;
  __m128 ret;
  lv_32fc_t* c = cVector;
  const lv_8sc_t* a = aVector;
  const lv_8sc_t* b = bVector;
  __m128i conjugateSign = _mm_set_epi16(-1, 1, -1, 1, -1, 1, -1, 1);

  __m128 invScalar = _mm_set_ps1(1.0/scalar);

  for(;number < quarterPoints; number++){
    // Convert into 8 bit values into 16 bit values
    x = _mm_cvtepi8_epi16(_mm_loadl_epi64((__m128i*)a));
    y = _mm_cvtepi8_epi16(_mm_loadl_epi64((__m128i*)b));

    // Calculate the ar*cr - ai*(-ci) portions
    realz = _mm_madd_epi16(x,y);

    // Calculate the complex conjugate of the cr + ci j values
    y = _mm_sign_epi16(y, conjugateSign);

    // Shift the order of the cr and ci values
    y = _mm_shufflehi_epi16(_mm_shufflelo_epi16(y, _MM_SHUFFLE(2,3,0,1) ), _MM_SHUFFLE(2,3,0,1));

    // Calculate the ar*(-ci) + cr*(ai)
    imagz = _mm_madd_epi16(x,y);

    // Interleave real and imaginary and then convert to float values
    ret = _mm_cvtepi32_ps(_mm_unpacklo_epi32(realz, imagz));

    // Normalize the floating point values
    ret = _mm_mul_ps(ret, invScalar);

    // Store the floating point values
    _mm_store_ps((float*)c, ret);
    c += 2;

    // Interleave real and imaginary and then convert to float values
    ret = _mm_cvtepi32_ps(_mm_unpackhi_epi32(realz, imagz));

    // Normalize the floating point values
    ret = _mm_mul_ps(ret, invScalar);

    // Store the floating point values
    _mm_store_ps((float*)c, ret);
    c += 2;

    a += 4;
    b += 4;
  }

  number = quarterPoints * 4;
  float* cFloatPtr = (float*)&cVector[number];
  int8_t* a8Ptr = (int8_t*)&aVector[number];
  int8_t* b8Ptr = (int8_t*)&bVector[number];
  for(; number < num_points; number++){
    float aReal =  (float)*a8Ptr++;
    float aImag =  (float)*a8Ptr++;
    lv_32fc_t aVal = lv_cmake(aReal, aImag );
    float bReal = (float)*b8Ptr++;
    float bImag = (float)*b8Ptr++;
    lv_32fc_t bVal = lv_cmake( bReal, -bImag );
    lv_32fc_t temp = aVal * bVal;

    *cFloatPtr++ = lv_creal(temp) / scalar;
    *cFloatPtr++ = lv_cimag(temp) / scalar;
  }
}
#endif /* LV_HAVE_SSE4_1 */


#ifdef LV_HAVE_GENERIC

static inline void
volk_8ic_x2_s32f_multiply_conjugate_32fc_generic(lv_32fc_t* cVector, const lv_8sc_t* aVector,
                                                 const lv_8sc_t* bVector, const float scalar,
                                                 unsigned int num_points)
{
  unsigned int number = 0;
  float* cPtr = (float*)cVector;
  const float invScalar = 1.0 / scalar;
  int8_t* a8Ptr = (int8_t*)aVector;
  int8_t* b8Ptr = (int8_t*)bVector;
  for(number = 0; number < num_points; number++){
    float aReal =  (float)*a8Ptr++;
    float aImag =  (float)*a8Ptr++;
    lv_32fc_t aVal = lv_cmake(aReal, aImag );
    float bReal = (float)*b8Ptr++;
    float bImag = (float)*b8Ptr++;
    lv_32fc_t bVal = lv_cmake( bReal, -bImag );
    lv_32fc_t temp = aVal * bVal;

    *cPtr++ = (lv_creal(temp) * invScalar);
    *cPtr++ = (lv_cimag(temp) * invScalar);
  }
}
#endif /* LV_HAVE_GENERIC */


#endif /* INCLUDED_volk_8ic_x2_s32f_multiply_conjugate_32fc_a_H */
