text: /* ----------------------------------------------------------------------
     LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
     http://lammps.sandia.gov, Sandia National Laboratories
     Steve Plimpton, sjplimp@sandia.gov
  
     This software is distributed under the GNU General Public License.
  
     See the README file in the top-level LAMMPS directory.
  ------------------------------------------------------------------------- */
  
  /* ----------------------------------------------------------------------
     Contributing author: Axel Kohlmeyer (Temple U)
  ------------------------------------------------------------------------- */
  
  #include <math.h>
  #include "pair_vashishta_table_omp.h"
  #include "atom.h"
  #include "comm.h"
  #include "force.h"
  #include "memory.h"
  #include "neighbor.h"
  #include "neigh_list.h"
  
  #include "suffix.h"
  using namespace LAMMPS_NS;
  
  /* ---------------------------------------------------------------------- */
  
  PairVashishtaTableOMP::PairVashishtaTableOMP(LAMMPS *lmp) :
    PairVashishtaTable(lmp), ThrOMP(lmp, THR_PAIR)
  {
    suffix_flag |= Suffix::OMP;
    respa_enable = 0;
  }
  
  /* ---------------------------------------------------------------------- */
  
  void PairVashishtaTableOMP::compute(int eflag, int vflag)
  {
    if (eflag || vflag) {
      ev_setup(eflag,vflag);
    } else evflag = vflag_fdotr = 0;
  
    const int nall = atom->nlocal + atom->nghost;
    const int nthreads = comm->nthreads;
    const int inum = list->inum;
  
  #if defined(_OPENMP)
  #pragma omp parallel default(none) shared(eflag,vflag)
  #endif
    {
      int ifrom, ito, tid;
  
      loop_setup_thr(ifrom, ito, tid, inum, nthreads);
      ThrData *thr = fix->get_thr(tid);
      thr->timer(Timer::START);
      ev_setup_thr(eflag, vflag, nall, eatom, vatom, thr);
  
      if (evflag) {
        if (eflag) {
          eval<1,1>(ifrom, ito, thr);
        } else {
          eval<1,0>(ifrom, ito, thr);
        }
      } else eval<0,0>(ifrom, ito, thr);
  
      thr->timer(Timer::PAIR);
      reduce_thr(this, eflag, vflag, thr);
    } // end of omp parallel region
  }
  
  template <int EVFLAG, int EFLAG>
  void PairVashishtaTableOMP::eval(int iifrom, int iito, ThrData * const thr)
  {
    int i,j,k,ii,jj,kk,jnum,jnumm1,maxshort_thr;
    tagint itag,jtag;
    int itype,jtype,ktype,ijparam,ikparam,ijkparam;
    double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
    double rsq,rsq1,rsq2;
    double delr1[3],delr2[3],fj[3],fk[3];
    int *ilist,*jlist,*numneigh,**firstneigh,*neighshort_thr;
  
    evdwl = 0.0;
  
    const dbl3_t * _noalias const x = (dbl3_t *) atom->x[0];
    dbl3_t * _noalias const f = (dbl3_t *) thr->get_f()[0];
    const tagint * _noalias const tag = atom->tag;
    const int * _noalias const type = atom->type;
    const int nlocal = atom->nlocal;
    const double cutshortsq = r0max*r0max;
  
    ilist = list->ilist;
    numneigh = list->numneigh;
    firstneigh = list->firstneigh;
    maxshort_thr = maxshort;
    memory->create(neighshort_thr,maxshort_thr,"pair_thr:neighshort_thr");
  
    double fxtmp,fytmp,fztmp;
  
    // loop over full neighbor list of my atoms
  
    for (ii = iifrom; ii < iito; ++ii) {
  
      i = ilist[ii];
      itag = tag[i];
      itype = map[type[i]];
      xtmp = x[i].x;
      ytmp = x[i].y;
      ztmp = x[i].z;
      fxtmp = fytmp = fztmp = 0.0;
  
      // two-body interactions, skip half of them
  
      jlist = firstneigh[i];
      jnum = numneigh[i];
      int numshort = 0;
  
      for (jj = 0; jj < jnum; jj++) {
        j = jlist[jj];
        j &= NEIGHMASK;
  
        delx = xtmp - x[j].x;
        dely = ytmp - x[j].y;
        delz = ztmp - x[j].z;
        rsq = delx*delx + dely*dely + delz*delz;
  
        if (rsq < cutshortsq) {
          neighshort_thr[numshort++] = j;
          if (numshort >= maxshort_thr) {
            maxshort_thr += maxshort_thr/2;
            memory->grow(neighshort_thr,maxshort_thr,"pair_thr:neighshort_thr");
          }
        }
  
        jtag = tag[j];
        if (itag > jtag) {
          if ((itag+jtag) % 2 == 0) continue;
        } else if (itag < jtag) {
          if ((itag+jtag) % 2 == 1) continue;
        } else {
          if (x[j].z < ztmp) continue;
          if (x[j].z == ztmp && x[j].y < ytmp) continue;
          if (x[j].z == ztmp && x[j].y == ytmp && x[j].x < xtmp) continue;
        }
  
        jtype = map[type[j]];
        ijparam = elem2param[itype][jtype][jtype];
        if (rsq >= params[ijparam].cutsq) continue;
  
        twobody_table(params[ijparam],rsq,fpair,EFLAG,evdwl);
  
        fxtmp += delx*fpair;
        fytmp += dely*fpair;
        fztmp += delz*fpair;
        f[j].x -= delx*fpair;
        f[j].y -= dely*fpair;
        f[j].z -= delz*fpair;
  
        if (EVFLAG) ev_tally_thr(this,i,j,nlocal,/* newton_pair */ 1,
                                 evdwl,0.0,fpair,delx,dely,delz,thr);
      }
  
      jnumm1 = numshort - 1;
  
      for (jj = 0; jj < jnumm1; jj++) {
        j = neighshort_thr[jj];
        jtype = map[type[j]];
        ijparam = elem2param[itype][jtype][jtype];
        delr1[0] = x[j].x - xtmp;
        delr1[1] = x[j].y - ytmp;
        delr1[2] = x[j].z - ztmp;
        rsq1 = delr1[0]*delr1[0] + delr1[1]*delr1[1] + delr1[2]*delr1[2];
        if (rsq1 >= params[ijparam].cutsq2) continue;
  
        double fjxtmp,fjytmp,fjztmp;
        fjxtmp = fjytmp = fjztmp = 0.0;
  
        for (kk = jj+1; kk < numshort; kk++) {
          k = neighshort_thr[kk];
          ktype = map[type[k]];
          ikparam = elem2param[itype][ktype][ktype];
          ijkparam = elem2param[itype][jtype][ktype];
  
          delr2[0] = x[k].x - xtmp;
          delr2[1] = x[k].y - ytmp;
          delr2[2] = x[k].z - ztmp;
          rsq2 = delr2[0]*delr2[0] + delr2[1]*delr2[1] + delr2[2]*delr2[2];
          if (rsq2 >= params[ikparam].cutsq2) continue;
  
          threebody(&params[ijparam],&params[ikparam],&params[ijkparam],
                    rsq1,rsq2,delr1,delr2,fj,fk,EFLAG,evdwl);
  
          fxtmp -= fj[0] + fk[0];
          fytmp -= fj[1] + fk[1];
          fztmp -= fj[2] + fk[2];
          fjxtmp += fj[0];
          fjytmp += fj[1];
          fjztmp += fj[2];
          f[k].x += fk[0];
          f[k].y += fk[1];
          f[k].z += fk[2];
  
          if (EVFLAG) ev_tally3_thr(this,i,j,k,evdwl,0.0,fj,fk,delr1,delr2,thr);
        }
        f[j].x += fjxtmp;
        f[j].y += fjytmp;
        f[j].z += fjztmp;
      }
      f[i].x += fxtmp;
      f[i].y += fytmp;
      f[i].z += fztmp;
    }
    memory->destroy(neighshort_thr);
  }
  
  /* ---------------------------------------------------------------------- */
  
  double PairVashishtaTableOMP::memory_usage()
  {
    double bytes = memory_usage_thr();
    bytes += PairVashishtaTable::memory_usage();
  
    return bytes;
  }
  