include /omp variant into plugin example

examples/plugins/Makefile

@@ -1,15 +1,16 @@
 CXX=mpicxx
-CXXFLAGS=-I../../src -Wall -O3 -fPIC
+CXXFLAGS=-I../../src -Wall -O3 -fPIC -I../../src/USER-OMP -fopenmp
-LD=$(CXX) -shared -rdynamic
+LD=$(CXX) -shared -rdynamic -fopenmp
 
-morse2plugin.so: morse2plugin.o pair_morse2.o
+morse2plugin.so: morse2plugin.o pair_morse2.o pair_morse2_omp.o
 	$(LD) -o $@ $^
 
 .cpp.o:
 	$(CXX) -o $@ $(CXXFLAGS) -c $<
 
 pair_morse2.o: pair_morse2.cpp pair_morse2.h
-morse2plugin.o: morse2plugin.cpp pair_morse2.h
+pair_morse2_omp.o: pair_morse2_omp.cpp pair_morse2_omp.h pair_morse2.h
+morse2plugin.o: morse2plugin.cpp pair_morse2.h pair_morse2_omp.h
 
 clean:
 	rm -f *~ *.so *.o log.lammps

examples/plugins/morse2plugin.cpp

@@ -7,6 +7,7 @@
 #include <cstring>
 
 #include "pair_morse2.h"
+#include "pair_morse2_omp.h"
 
 using namespace LAMMPS_NS;
 
@@ -15,6 +16,11 @@ static Pair *morse2creator(LAMMPS *lmp)
     return new PairMorse2(lmp);
 }
 
+static Pair *morse2ompcreator(LAMMPS *lmp)
+{
+    return new PairMorse2OMP(lmp);
+}
+
 static lammpsplugin_t plugin;
 void lammpsplugin_init(void *lmp)
 {
@@ -24,6 +30,11 @@ void lammpsplugin_init(void *lmp)
     plugin.name    = "morse2";
     plugin.info    = "Morse2 variant pair style v1.0 by Axel Kohlmeyer";
     plugin.creator = (lammpsplugin_factory *) &morse2creator;
-    
+    lammpsplugin_register(&plugin, (LAMMPS *)lmp);
+
+    plugin.style   = "pair";
+    plugin.name    = "morse2/omp";
+    plugin.info    = "Morse2 variant pair style for OpenMP v1.0 by Axel Kohlmeyer";
+    plugin.creator = (lammpsplugin_factory *) &morse2ompcreator;
     lammpsplugin_register(&plugin, (LAMMPS *)lmp);
 }

examples/plugins/pair_morse2_omp.cpp

@@ -0,0 +1,160 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://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 "pair_morse2_omp.h"
+
+#include "atom.h"
+#include "comm.h"
+#include "force.h"
+#include "neigh_list.h"
+#include "suffix.h"
+
+#include <cmath>
+
+#include "omp_compat.h"
+using namespace LAMMPS_NS;
+
+/* ---------------------------------------------------------------------- */
+
+PairMorse2OMP::PairMorse2OMP(LAMMPS *lmp) :
+  PairMorse2(lmp), ThrOMP(lmp, THR_PAIR)
+{
+  suffix_flag |= Suffix::OMP;
+  respa_enable = 0;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void PairMorse2OMP::compute(int eflag, int vflag)
+{
+  ev_init(eflag,vflag);
+
+  const int nall = atom->nlocal + atom->nghost;
+  const int nthreads = comm->nthreads;
+  const int inum = list->inum;
+
+#if defined(_OPENMP)
+#pragma omp parallel LMP_DEFAULT_NONE LMP_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, nullptr, thr);
+
+    if (evflag) {
+      if (eflag) {
+        if (force->newton_pair) eval<1,1,1>(ifrom, ito, thr);
+        else eval<1,1,0>(ifrom, ito, thr);
+      } else {
+        if (force->newton_pair) eval<1,0,1>(ifrom, ito, thr);
+        else eval<1,0,0>(ifrom, ito, thr);
+      }
+    } else {
+      if (force->newton_pair) eval<0,0,1>(ifrom, ito, thr);
+      else eval<0,0,0>(ifrom, ito, thr);
+    }
+
+    thr->timer(Timer::PAIR);
+    reduce_thr(this, eflag, vflag, thr);
+  } // end of omp parallel region
+}
+
+template <int EVFLAG, int EFLAG, int NEWTON_PAIR>
+void PairMorse2OMP::eval(int iifrom, int iito, ThrData * const thr)
+{
+  int i,j,ii,jj,jnum,itype,jtype;
+  double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
+  double rsq,r,dr,dexp,factor_lj;
+  int *ilist,*jlist,*numneigh,**firstneigh;
+
+  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 int * _noalias const type = atom->type;
+  const int nlocal = atom->nlocal;
+  const double * _noalias const special_lj = force->special_lj;
+  double fxtmp,fytmp,fztmp;
+
+  ilist = list->ilist;
+  numneigh = list->numneigh;
+  firstneigh = list->firstneigh;
+
+  // loop over neighbors of my atoms
+
+  for (ii = iifrom; ii < iito; ++ii) {
+
+    i = ilist[ii];
+    xtmp = x[i].x;
+    ytmp = x[i].y;
+    ztmp = x[i].z;
+    itype = type[i];
+    jlist = firstneigh[i];
+    jnum = numneigh[i];
+    fxtmp=fytmp=fztmp=0.0;
+
+    for (jj = 0; jj < jnum; jj++) {
+      j = jlist[jj];
+      factor_lj = special_lj[sbmask(j)];
+      j &= NEIGHMASK;
+
+      delx = xtmp - x[j].x;
+      dely = ytmp - x[j].y;
+      delz = ztmp - x[j].z;
+      rsq = delx*delx + dely*dely + delz*delz;
+      jtype = type[j];
+
+      if (rsq < cutsq[itype][jtype]) {
+        r = sqrt(rsq);
+        dr = r - r0[itype][jtype];
+        dexp = exp(-alpha[itype][jtype] * dr);
+        fpair = factor_lj * morse1[itype][jtype] * (dexp*dexp - dexp) / r;
+
+        fxtmp += delx*fpair;
+        fytmp += dely*fpair;
+        fztmp += delz*fpair;
+        if (NEWTON_PAIR || j < nlocal) {
+          f[j].x -= delx*fpair;
+          f[j].y -= dely*fpair;
+          f[j].z -= delz*fpair;
+        }
+
+        if (EFLAG) {
+          evdwl = d0[itype][jtype] * (dexp*dexp - 2.0*dexp) -
+            offset[itype][jtype];
+          evdwl *= factor_lj;
+        }
+
+        if (EVFLAG) ev_tally_thr(this,i,j,nlocal,NEWTON_PAIR,
+                                 evdwl,0.0,fpair,delx,dely,delz,thr);
+      }
+    }
+    f[i].x += fxtmp;
+    f[i].y += fytmp;
+    f[i].z += fztmp;
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
+double PairMorse2OMP::memory_usage()
+{
+  double bytes = memory_usage_thr();
+  bytes += PairMorse2::memory_usage();
+
+  return bytes;
+}

examples/plugins/pair_morse2_omp.h

@@ -0,0 +1,41 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  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)
+------------------------------------------------------------------------- */
+
+#ifndef LMP_PAIR_MORSE2_OMP_H
+#define LMP_PAIR_MORSE2_OMP_H
+
+#include "pair_morse2.h"
+#include "thr_omp.h"
+
+namespace LAMMPS_NS {
+
+class PairMorse2OMP : public PairMorse2, public ThrOMP {
+
+ public:
+  PairMorse2OMP(class LAMMPS *);
+
+  virtual void compute(int, int);
+  virtual double memory_usage();
+
+ private:
+  template <int EVFLAG, int EFLAG, int NEWTON_PAIR>
+  void eval(int ifrom, int ito, ThrData * const thr);
+};
+
+}
+
+#endif