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lammps/src/USER-INTEL/fix_nve_intel.cpp
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fix_nve_intel.cpp
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/* ----------------------------------------------------------------------
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: W. Michael Brown (Intel)
------------------------------------------------------------------------- */
#include "fix_nve_intel.h"
#include "atom.h"
#include "force.h"
#include "intel_preprocess.h"
#include "memory.h"
#include "neighbor.h"
#include "update.h"
using namespace LAMMPS_NS;
using namespace FixConst;
/* ---------------------------------------------------------------------- */
FixNVEIntel::FixNVEIntel(LAMMPS *lmp, int narg, char **arg) :
FixNVE(lmp, narg, arg)
{
_dtfm = 0;
_nlocal3 = 0;
_nlocal_max = 0;
}
/* ---------------------------------------------------------------------- */
FixNVEIntel::~FixNVEIntel()
{
memory->destroy(_dtfm);
}
/* ---------------------------------------------------------------------- */
void FixNVEIntel::setup(int vflag)
{
FixNVE::setup(vflag);
_nlocal3 = 3 * atom->nlocal;
if (atom->ntypes > 1) reset_dt();
}
/* ----------------------------------------------------------------------
allow for both per-type and per-atom mass
------------------------------------------------------------------------- */
void FixNVEIntel::initial_integrate(int vflag)
{
// update v and x of atoms in group
double * _noalias const x = atom->x[0];
double * _noalias const v = atom->v[0];
const double * _noalias const f = atom->f[0];
if (igroup == 0 && atom->ntypes == 1 && !atom->rmass) {
const double dtfm = dtf / atom->mass[1];
#if defined(LMP_SIMD_COMPILER)
#pragma vector aligned
#pragma simd
#endif
for (int i = 0; i < _nlocal3; i++) {
v[i] += dtfm * f[i];
x[i] += dtv * v[i];
}
} else if (igroup == 0) {
#if defined(LMP_SIMD_COMPILER)
#pragma vector aligned
#pragma simd
#endif
for (int i = 0; i < _nlocal3; i++) {
v[i] += _dtfm[i] * f[i];
x[i] += dtv * v[i];
}
} else {
#if defined(LMP_SIMD_COMPILER)
#pragma vector aligned
#pragma simd
#endif
for (int i = 0; i < _nlocal3; i++) {
if (_dtfm[i] != 0.0) {
v[i] += _dtfm[i] * f[i];
x[i] += dtv * v[i];
}
}
}
}
/* ---------------------------------------------------------------------- */
void FixNVEIntel::final_integrate()
{
// update v of atoms in group
double * _noalias const v = atom->v[0];
const double * _noalias const f = atom->f[0];
if (igroup == 0 && atom->ntypes == 1 && !atom->rmass) {
_nlocal3 = 3 * atom->nlocal;
const double dtfm = dtf / atom->mass[1];
#if defined(LMP_SIMD_COMPILER)
#pragma vector aligned
#pragma simd
#endif
for (int i = 0; i < _nlocal3; i++)
v[i] += dtfm * f[i];
} else {
if (neighbor->ago == 0) reset_dt();
#if defined(LMP_SIMD_COMPILER)
#pragma vector aligned
#pragma simd
#endif
for (int i = 0; i < _nlocal3; i++)
v[i] += _dtfm[i] * f[i];
}
}
void FixNVEIntel::reset_dt() {
dtv = update->dt;
dtf = 0.5 * update->dt * force->ftm2v;
const int * const mask = atom->mask;
const int nlocal = (igroup == atom->firstgroup) ? atom->nfirst :
atom->nlocal;
if (nlocal > _nlocal_max) {
if (_nlocal_max) memory->destroy(_dtfm);
_nlocal_max = static_cast<int>(1.20 * nlocal);
memory->create(_dtfm, _nlocal_max * 3, "fix_nve_intel:dtfm");
}
_nlocal3 = nlocal * 3;
if (igroup == 0) {
if (atom->rmass) {
const double * const rmass = atom->rmass;
int n = 0;
for (int i = 0; i < nlocal; i++) {
_dtfm[n++] = dtf / rmass[i];
_dtfm[n++] = dtf / rmass[i];
_dtfm[n++] = dtf / rmass[i];
}
} else {
const double * const mass = atom->mass;
const int * const type = atom->type;
int n = 0;
for (int i = 0; i < nlocal; i++) {
_dtfm[n++] = dtf / mass[type[i]];
_dtfm[n++] = dtf / mass[type[i]];
_dtfm[n++] = dtf / mass[type[i]];
}
}
} else {
if (atom->rmass) {
const double * const rmass = atom->rmass;
int n = 0;
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
_dtfm[n++] = dtf / rmass[i];
_dtfm[n++] = dtf / rmass[i];
_dtfm[n++] = dtf / rmass[i];
} else {
_dtfm[n++] = 0.0;
_dtfm[n++] = 0.0;
_dtfm[n++] = 0.0;
}
} else {
const double * const mass = atom->mass;
const int * const type = atom->type;
int n = 0;
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
_dtfm[n++] = dtf / mass[type[i]];
_dtfm[n++] = dtf / mass[type[i]];
_dtfm[n++] = dtf / mass[type[i]];
} else {
_dtfm[n++] = 0.0;
_dtfm[n++] = 0.0;
_dtfm[n++] = 0.0;
}
}
}
}
double FixNVEIntel::memory_usage()
{
return FixNVE::memory_usage() + _nlocal_max * 3 * sizeof(double);
}
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