lammps/lib/gpu/lal_buck_coul.h

/***************************************************************************
                                 buck_coul.h
                             -------------------
                           Trung Dac Nguyen (ORNL)

  Class for acceleration of the buck/coul/cut pair style.

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

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

#ifndef LAL_BUCK_COUL_H
#define LAL_BUCK_COUL_H

#include "lal_base_charge.h"

namespace LAMMPS_AL {

template <class numtyp, class acctyp>
class BuckCoul : public BaseCharge<numtyp, acctyp> {
 public:
  BuckCoul();
  ~BuckCoul();

  /// Clear any previous data and set up for a new LAMMPS run
  /** \param max_nbors initial number of rows in the neighbor matrix
    * \param cell_size cutoff + skin
    * \param gpu_split fraction of particles handled by device
    *
    * Returns:
    * -  0 if successfull
    * - -1 if fix gpu not found
    * - -3 if there is an out of memory error
    * - -4 if the GPU library was not compiled for GPU
    * - -5 Double precision is not supported on card **/
  int init(const int ntypes, double **host_cutsq,
           double **host_rhoinv, double **host_buck1, double **host_buck2,
           double **host_a, double **host_c,
           double **host_offset, 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, double **host_cut_ljsq,
           double **host_cut_coulsq, double *host_special_coul,
           const double qqrd2e);

  /// Clear all host and device data
  /** \note This is called at the beginning of the init() routine **/
  void clear();

  /// Returns memory usage on device per atom
  int bytes_per_atom(const int max_nbors) const;

  /// Total host memory used by library for pair style
  double host_memory_usage() const;

  // --------------------------- TYPE DATA --------------------------

  /// coeff1.x = rhoinv, coeff1.y = buck1, coeff1.z = buck2
  UCL_D_Vec<numtyp4> coeff1;
  /// coeff2.x = a, coeff2.y = c, coeff2.z = offset
  UCL_D_Vec<numtyp4> coeff2;
  /// cutsq.x = cutsq, cutsq.y = cutsq_lj, cutsq.z = cutsq_coul
  UCL_D_Vec<numtyp4> cutsq;
  /// Special LJ values
  UCL_D_Vec<numtyp> sp_lj;

  /// If atom type constants fit in shared memory, use fast kernels
  bool shared_types;

  /// Number of atom types
  int _lj_types;

  numtyp _qqrd2e;

 private:
  bool _allocated;
  void loop(const bool _eflag, const bool _vflag);
};

}

#endif