/*************************************************************************************

Grid physics library, www.github.com/paboyle/Grid

Source file: ./lib/qcd/action/fermion/WilsonKernels.h

Copyright (C) 2015

Author: Peter Boyle <pabobyle@ph.ed.ac.uk>
Author: Peter Boyle <paboyle@ph.ed.ac.uk>
Author: paboyle <paboyle@ph.ed.ac.uk>

This program 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 2 of the License, or
(at your option) any later version.

This program 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 this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

See the full license in the file "LICENSE" in the top level distribution
directory
*************************************************************************************/
/*  END LEGAL */
#ifndef GRID_QCD_DHOP_H
#define GRID_QCD_DHOP_H

namespace Grid {

namespace QCD {

////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Helper routines that implement Wilson stencil for a single site.
// Common to both the WilsonFermion and WilsonFermion5D
////////////////////////////////////////////////////////////////////////////////////////////////////////////////
class WilsonKernelsStatic {
 public:
  // S-direction is INNERMOST and takes no part in the parity.
  static int AsmOpt;   // these are a temporary hack
  static int HandOpt;  // these are a temporary hack
};

template <class Impl>
class WilsonKernels : public FermionOperator<Impl>, public WilsonKernelsStatic {
 public:
  INHERIT_IMPL_TYPES(Impl);
  typedef FermionOperator<Impl> Base;

 public:
  template <bool EnableBool = true>
  typename std::enable_if<Impl::Dimension == 3 && Nc == 3 &&EnableBool, void>::type
  DiracOptDhopSite(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, int Ls, int Ns, const FermionField &in,
      FermionField &out) {
#ifdef AVX512
    if (AsmOpt) {
      WilsonKernels<Impl>::DiracOptAsmDhopSite(st, lo, U, buf, sF, sU, Ls, Ns,
                                               in, out);

    } else {
#else
    {
#endif
      for (int site = 0; site < Ns; site++) {
        for (int s = 0; s < Ls; s++) {
          if (HandOpt)
            WilsonKernels<Impl>::DiracOptHandDhopSite(st, lo, U, buf, sF, sU,
                                                      in, out);
          else
            WilsonKernels<Impl>::DiracOptGenericDhopSite(st, lo, U, buf, sF, sU,
                                                         in, out);
          sF++;
        }
        sU++;
      }
    }
  }

  template <bool EnableBool = true>
    typename std::enable_if<(Impl::Dimension != 3 || (Impl::Dimension == 3 && Nc != 3)) && EnableBool, void>::type
  DiracOptDhopSite(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, int Ls, int Ns, const FermionField &in,
      FermionField &out) {
    for (int site = 0; site < Ns; site++) {
      for (int s = 0; s < Ls; s++) {
        WilsonKernels<Impl>::DiracOptGenericDhopSite(st, lo, U, buf, sF, sU, in,
                                                     out);
        sF++;
      }
      sU++;
    }
  }

  template <bool EnableBool = true>
  typename std::enable_if<Impl::Dimension == 3 && Nc== 3 && EnableBool, void>::type
  DiracOptDhopSiteDag(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, int Ls, int Ns, const FermionField &in, FermionField &out) {
    // No asm implementation yet.
    //  if ( AsmOpt )
    //  WilsonKernels<Impl>::DiracOptAsmDhopSiteDag(st,lo,U,buf,sF,sU,in,out);
    //  else
    for (int site = 0; site < Ns; site++) {
      for (int s = 0; s < Ls; s++) {
        if (HandOpt)
          WilsonKernels<Impl>::DiracOptHandDhopSiteDag(st, lo, U, buf, sF, sU,
                                                       in, out);
        else
          WilsonKernels<Impl>::DiracOptGenericDhopSiteDag(st, lo, U, buf, sF,
                                                          sU, in, out);
        sF++;
      }
      sU++;
    }
  }

  template <bool EnableBool = true>
    typename std::enable_if<(Impl::Dimension != 3 || (Impl::Dimension == 3 && Nc != 3)) && EnableBool, void>::type
    DiracOptDhopSiteDag(
			StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
			std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
			int sF, int sU, int Ls, int Ns, const FermionField &in, FermionField &out) {
    for (int site = 0; site < Ns; site++) {
      for (int s = 0; s < Ls; s++) {
        WilsonKernels<Impl>::DiracOptGenericDhopSiteDag(st, lo, U, buf, sF, sU,
                                                        in, out);
        sF++;
      }
      sU++;
    }
  }
  
  void DiracOptDhopDir(
      StencilImpl &st, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, const FermionField &in, FermionField &out, int dirdisp,
      int gamma);

 private:
  // Specialised variants
  void DiracOptGenericDhopSite(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, const FermionField &in, FermionField &out);

  void DiracOptGenericDhopSiteDag(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, const FermionField &in, FermionField &out);

  void DiracOptAsmDhopSite(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, int Ls, int Ns, const FermionField &in,
      FermionField &out);

  void DiracOptHandDhopSite(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, const FermionField &in, FermionField &out);

  void DiracOptHandDhopSiteDag(
      StencilImpl &st, LebesgueOrder &lo, DoubledGaugeField &U,
      std::vector<SiteHalfSpinor, alignedAllocator<SiteHalfSpinor> > &buf,
      int sF, int sU, const FermionField &in, FermionField &out);

 public:
  WilsonKernels(const ImplParams &p = ImplParams());
};
}
}
#endif