text: //***************************************************************************/
  // This software is released under the 2-Clause BSD license, included
  // below.
  //
  // Copyright (c) 2019, Aous Naman 
  // Copyright (c) 2019, Kakadu Software Pty Ltd, Australia
  // Copyright (c) 2019, The University of New South Wales, Australia
  // 
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  // 
  // 1. Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  // 
  // 2. 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.
  // 
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  // IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  // TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  // PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //***************************************************************************/
  // This file is part of the OpenJPH software implementation.
  // File: ojph_colour_avx2.cpp
  // Author: Aous Naman
  // Date: 11 October 2019
  //***************************************************************************/
  
  #include <cmath>
  
  #include "ojph_defs.h"
  #include "ojph_arch.h"
  #include "ojph_colour.h"
  
  #ifdef OJPH_COMPILER_MSVC
  #include <intrin.h>
  #else
  #include <x86intrin.h>
  #endif
  
  namespace ojph {
    namespace local {
  
      //////////////////////////////////////////////////////////////////////////
      void avx2_cnvrt_si32_to_si32_shftd(const si32 *sp, si32 *dp, int shift,
                                         ui32 width)
      {
        __m256i sh = _mm256_set1_epi32(shift);
        for (int i = (width + 7) >> 3; i > 0; --i, sp+=8, dp+=8)
        {
          __m256i s = _mm256_loadu_si256((__m256i*)sp);
          s = _mm256_add_epi32(s, sh);
          _mm256_storeu_si256((__m256i*)dp, s);
        }
      }
  
      //////////////////////////////////////////////////////////////////////////
      void avx2_rct_forward(const si32 *r, const si32 *g, const si32 *b,
                            si32 *y, si32 *cb, si32 *cr, ui32 repeat)
      {
        for (int i = (repeat + 7) >> 3; i > 0; --i)
        {
          __m256i mr = _mm256_load_si256((__m256i*)r);
          __m256i mg = _mm256_load_si256((__m256i*)g);
          __m256i mb = _mm256_load_si256((__m256i*)b);
          __m256i t = _mm256_add_epi32(mr, mb);
          t = _mm256_add_epi32(t, _mm256_slli_epi32(mg, 1));
          _mm256_store_si256((__m256i*)y, _mm256_srai_epi32(t, 2));
          t = _mm256_sub_epi32(mb, mg);
          _mm256_store_si256((__m256i*)cb, t);
          t = _mm256_sub_epi32(mr, mg);
          _mm256_store_si256((__m256i*)cr, t);
  
          r += 8; g += 8; b += 8;
          y += 8; cb += 8; cr += 8;
        }
      }
  
      //////////////////////////////////////////////////////////////////////////
      void avx2_rct_backward(const si32 *y, const si32 *cb, const si32 *cr,
                             si32 *r, si32 *g, si32 *b, ui32 repeat)
      {
        for (int i = (repeat + 7) >> 3; i > 0; --i)
        {
          __m256i my  = _mm256_load_si256((__m256i*)y);
          __m256i mcb = _mm256_load_si256((__m256i*)cb);
          __m256i mcr = _mm256_load_si256((__m256i*)cr);
  
          __m256i t = _mm256_add_epi32(mcb, mcr);
          t = _mm256_sub_epi32(my, _mm256_srai_epi32(t, 2));
          _mm256_store_si256((__m256i*)g, t);
          __m256i u = _mm256_add_epi32(mcb, t);
          _mm256_store_si256((__m256i*)b, u);
          u = _mm256_add_epi32(mcr, t);
          _mm256_store_si256((__m256i*)r, u);
  
          y += 8; cb += 8; cr += 8;
          r += 8; g += 8; b += 8;
        }
      }
  
    }
  }
  