/***************************************************************************
                                lal_table.cpp
                             -------------------
                    Trung Dac Nguyen, W. Michael Brown (ORNL)

  Class for acceleration of the table pair style.

 __________________________________________________________________________
    This file is part of the LAMMPS Accelerator Library (LAMMPS_AL)
 __________________________________________________________________________

    begin                : 
    email                : brownw@ornl.gov nguyentd@ornl.gov
 ***************************************************************************/

#ifdef USE_OPENCL
#include "table_cl.h"
#else
#include "table_ptx.h"
#endif

#include "lal_table.h"
#include <cassert>
using namespace LAMMPS_AL;
#define TableT Table<numtyp, acctyp>

#define LOOKUP 0
#define LINEAR 1
#define SPLINE 2
#define BITMAP 3

extern Device<PRECISION,ACC_PRECISION> device;

template <class numtyp, class acctyp>
TableT::Table() : BaseAtomic<numtyp,acctyp>(), _allocated(false) {
}

template <class numtyp, class acctyp>
TableT::~Table() { 
  clear();
}
 
template <class numtyp, class acctyp>
int TableT::bytes_per_atom(const int max_nbors) const {
  return this->bytes_per_atom_atomic(max_nbors);
}

template <class numtyp, class acctyp>
int TableT::init(const int ntypes, 
                double **host_cutsq, double ***host_table_coeffs,
                double **host_table_data,
                double *host_special_lj, const int nlocal,
                const int nall, const int max_nbors,
                const int maxspecial, const double cell_size,
                const double gpu_split, FILE *_screen, 
                int tabstyle, int ntables, int tablength) {
  int success;
  success=this->init_atomic(nlocal,nall,max_nbors,maxspecial,cell_size,gpu_split,
                            _screen,table);
  if (success!=0)
    return success;

  // If atom type constants fit in shared memory use fast kernel
  int lj_types=ntypes;
  shared_types=false;
  int max_shared_types=this->device->max_shared_types();
  if (lj_types<=max_shared_types && this->_block_size>=max_shared_types) {
    lj_types=max_shared_types;
    shared_types=true;
  }
  _lj_types=lj_types;
  
  _tabstyle = tabstyle;
  _ntables = ntables;
  _tablength = tablength;
  
  // Allocate a host write buffer for data initialization
  UCL_H_Vec<numtyp4> host_write(lj_types*lj_types,*(this->ucl_device),
                               UCL_WRITE_OPTIMIZED);

  for (int i=0; i<lj_types*lj_types; i++) {
    host_write[i].x=(numtyp)0.0;
    host_write[i].y=(numtyp)0.0;
    host_write[i].z=(numtyp)0.0;
    host_write[i].w=(numtyp)0.0;
  }
  
  coeff1.alloc(lj_types*lj_types,*(this->ucl_device),UCL_READ_ONLY);
  for (int ix=1; ix<ntypes; ix++)
    for (int iy=1; iy<ntypes; iy++) {
      host_write[ix*lj_types+iy].x = host_table_coeffs[ix][iy][0]; // tabindex
      host_write[ix*lj_types+iy].y = host_table_coeffs[ix][iy][1]; // ntablebits
      host_write[ix*lj_types+iy].z = host_table_coeffs[ix][iy][2]; // nshiftbits
      host_write[ix*lj_types+iy].w = host_table_coeffs[ix][iy][3]; // nmask
  }
  ucl_copy(coeff1,host_write,false);
  
  coeff2.alloc(lj_types*lj_types,*(this->ucl_device),UCL_READ_ONLY);
  for (int ix=1; ix<ntypes; ix++)
    for (int iy=1; iy<ntypes; iy++) {
      host_write[ix*lj_types+iy].x = host_table_coeffs[ix][iy][4]; // innersq
      host_write[ix*lj_types+iy].y = host_table_coeffs[ix][iy][5]; // invdelta
      host_write[ix*lj_types+iy].z = host_table_coeffs[ix][iy][6]; // deltasq6
      host_write[ix*lj_types+iy].w = (numtyp)0.0;
  }
  ucl_copy(coeff2,host_write,false);
  
  // Allocate tablength arrays
  if (tabstyle == BITMAP) tablength = 1 << tablength;

  UCL_H_Vec<numtyp4> host_write2(ntables*tablength,*(this->ucl_device),
                               UCL_WRITE_OPTIMIZED);
  for (int i=0; i<ntables*tablength; i++) {
    host_write2[i].x = 0.0;
    host_write2[i].y = 0.0;
    host_write2[i].z = 0.0;
    host_write2[i].w = 0.0;
  }

  coeff3.alloc(ntables*tablength,*(this->ucl_device),UCL_READ_ONLY);
  for (int n=0; n<ntables; n++) {
    if (tabstyle == LOOKUP) {
      for (int k=0; k<tablength-1; k++) {
          host_write2[n*tablength+k].x = (numtyp)0;
          host_write2[n*tablength+k].y = host_table_data[n][8*k+1]; // e
          host_write2[n*tablength+k].z = host_table_data[n][8*k+2]; // f
          host_write2[n*tablength+k].w = (numtyp)0;
      }
    } else if (tabstyle == LINEAR || tabstyle == SPLINE || tabstyle == BITMAP) {
      for (int k=0; k<tablength; k++) {
          host_write2[n*tablength+k].x = host_table_data[n][8*k+0]; // rsq
          host_write2[n*tablength+k].y = host_table_data[n][8*k+1]; // e
          host_write2[n*tablength+k].z = host_table_data[n][8*k+2]; // f
          host_write2[n*tablength+k].w = (numtyp)0;
      }
    } 
  }
  ucl_copy(coeff3,host_write2,false);
  
  coeff4.alloc(ntables*tablength,*(this->ucl_device),UCL_READ_ONLY);
  for (int i=0; i<ntables*tablength; i++) {
    host_write2[i].x = 0.0;
    host_write2[i].y = 0.0;
    host_write2[i].z = 0.0;
    host_write2[i].w = 0.0;
  }

  for (int n=0; n<ntables; n++) {
    if (tabstyle == LINEAR) {
      for (int k=0; k<tablength-1; k++) {
        host_write2[n*tablength+k].x = (numtyp)0; 
        host_write2[n*tablength+k].y = host_table_data[n][8*k+3]; // de
        host_write2[n*tablength+k].z = host_table_data[n][8*k+4]; // df
        host_write2[n*tablength+k].w = (numtyp)0;
      }
    } else if (tabstyle == SPLINE) {
      for (int k=0; k<tablength; k++) {
        host_write2[n*tablength+k].x = (numtyp)0; 
        host_write2[n*tablength+k].y = host_table_data[n][8*k+3]; // e2
        host_write2[n*tablength+k].z = host_table_data[n][8*k+4]; // f2
        host_write2[n*tablength+k].w = (numtyp)0;
      }
    } else if (tabstyle == BITMAP) {
      for (int k=0; k<tablength; k++) {
        host_write2[n*tablength+k].x = (numtyp)0; 
        host_write2[n*tablength+k].y = host_table_data[n][8*k+3]; // de
        host_write2[n*tablength+k].z = host_table_data[n][8*k+4]; // df
        host_write2[n*tablength+k].w = host_table_data[n][8*k+5]; // drsq
      }
    }
  }
  ucl_copy(coeff4,host_write2,false);
  
  UCL_H_Vec<numtyp> host_rsq(lj_types*lj_types,*(this->ucl_device),
                               UCL_WRITE_OPTIMIZED);
  cutsq.alloc(lj_types*lj_types,*(this->ucl_device),UCL_READ_ONLY);
  this->atom->type_pack1(ntypes,lj_types,cutsq,host_rsq,host_cutsq);
            
  UCL_H_Vec<double> dview;
  sp_lj.alloc(4,*(this->ucl_device),UCL_READ_ONLY);
  dview.view(host_special_lj,4,*(this->ucl_device));
  ucl_copy(sp_lj,dview,false);

  _allocated=true;
  this->_max_bytes=coeff1.row_bytes()+coeff2.row_bytes()
    +coeff3.row_bytes()+coeff4.row_bytes()+cutsq.row_bytes()
    +sp_lj.row_bytes();
  return 0;
}

template <class numtyp, class acctyp>
void TableT::clear() {
  if (!_allocated)
    return;
  _allocated=false;

  coeff1.clear();
  coeff2.clear();
  coeff3.clear();
  coeff4.clear();
  sp_lj.clear();
  this->clear_atomic();
}

template <class numtyp, class acctyp>
double TableT::host_memory_usage() const {
  return this->host_memory_usage_atomic()+sizeof(Table<numtyp,acctyp>);
}

// ---------------------------------------------------------------------------
// Calculate energies, forces, and torques
// ---------------------------------------------------------------------------
template <class numtyp, class acctyp>
void TableT::loop(const bool _eflag, const bool _vflag) {
  // Compute the block size and grid size to keep all cores busy
  const int BX=this->block_size();
  int eflag, vflag;
  if (_eflag)
    eflag=1;
  else
    eflag=0;

  if (_vflag)
    vflag=1;
  else
    vflag=0;
  
  int GX=static_cast<int>(ceil(static_cast<double>(this->ans->inum())/
                               (BX/this->_threads_per_atom)));

  int ainum=this->ans->inum();
  int nbor_pitch=this->nbor->nbor_pitch();
  this->time_pair.start();
  if (shared_types) {
    this->k_pair_fast.set_size(GX,BX);
    this->k_pair_fast.run(&this->atom->dev_x.begin(), &coeff1.begin(), 
                          &coeff2.begin(), &coeff3.begin(),
                          &coeff4.begin(), &cutsq.begin(), &sp_lj.begin(),
                          &this->nbor->dev_nbor.begin(),
                          &this->_nbor_data->begin(),
                          &this->ans->dev_ans.begin(),
                          &this->ans->dev_engv.begin(), &eflag, &vflag,
                          &ainum, &nbor_pitch, &this->_threads_per_atom, 
                          &_tabstyle, &_tablength);
  } else {
    this->k_pair.set_size(GX,BX);
    this->k_pair.run(&this->atom->dev_x.begin(), &coeff1.begin(), 
                     &coeff2.begin(), &coeff3.begin(), &coeff4.begin(), &cutsq.begin(),
                     &_lj_types, &sp_lj.begin(), &this->nbor->dev_nbor.begin(),
                     &this->_nbor_data->begin(), &this->ans->dev_ans.begin(),
                     &this->ans->dev_engv.begin(), &eflag, &vflag, &ainum,
                     &nbor_pitch, &this->_threads_per_atom,
                     &_tabstyle, &_tablength);
  }
  this->time_pair.stop();
}

template class Table<PRECISION,ACC_PRECISION>;