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lammps/src/USER-INTEL/bond_harmonic_intel.cpp
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bond_harmonic_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 <math.h>
#include <stdlib.h>
#include "bond_harmonic_intel.h"
#include "atom.h"
#include "neighbor.h"
#include "domain.h"
#include "comm.h"
#include "force.h"
#include "memory.h"
#include "suffix.h"
#include "error.h"
using namespace LAMMPS_NS;
typedef struct { int a,b,t; } int3_t;
/* ---------------------------------------------------------------------- */
BondHarmonicIntel::BondHarmonicIntel(LAMMPS *lmp) : BondHarmonic(lmp)
{
suffix_flag |= Suffix::INTEL;
}
/* ---------------------------------------------------------------------- */
BondHarmonicIntel::~BondHarmonicIntel()
{
}
/* ---------------------------------------------------------------------- */
void BondHarmonicIntel::compute(int eflag, int vflag)
{
#ifdef _LMP_INTEL_OFFLOAD
if (_use_base) {
BondHarmonic::compute(eflag, vflag);
return;
}
#endif
if (fix->precision() == FixIntel::PREC_MODE_MIXED)
compute<float,double>(eflag, vflag, fix->get_mixed_buffers(),
force_const_single);
else if (fix->precision() == FixIntel::PREC_MODE_DOUBLE)
compute<double,double>(eflag, vflag, fix->get_double_buffers(),
force_const_double);
else
compute<float,float>(eflag, vflag, fix->get_single_buffers(),
force_const_single);
}
/* ---------------------------------------------------------------------- */
template <class flt_t, class acc_t>
void BondHarmonicIntel::compute(int eflag, int vflag,
IntelBuffers<flt_t,acc_t> *buffers,
const ForceConst<flt_t> &fc)
{
if (eflag || vflag) ev_setup(eflag,vflag);
else evflag = 0;
if (evflag) {
if (eflag) {
if (force->newton_bond)
eval<1,1,1>(vflag, buffers, fc);
else
eval<1,1,0>(vflag, buffers, fc);
} else {
if (force->newton_bond)
eval<1,0,1>(vflag, buffers, fc);
else
eval<1,0,0>(vflag, buffers, fc);
}
} else {
if (force->newton_bond)
eval<0,0,1>(vflag, buffers, fc);
else
eval<0,0,0>(vflag, buffers, fc);
}
}
template <int EVFLAG, int EFLAG, int NEWTON_BOND, class flt_t, class acc_t>
void BondHarmonicIntel::eval(const int vflag,
IntelBuffers<flt_t,acc_t> *buffers,
const ForceConst<flt_t> &fc)
{
const int inum = neighbor->nbondlist;
if (inum == 0) return;
ATOM_T * _noalias const x = buffers->get_x(0);
const int nlocal = atom->nlocal;
const int nall = nlocal + atom->nghost;
int f_stride;
if (NEWTON_BOND) f_stride = buffers->get_stride(nall);
else f_stride = buffers->get_stride(nlocal);
int tc;
FORCE_T * _noalias f_start;
acc_t * _noalias ev_global;
IP_PRE_get_buffers(0, buffers, fix, tc, f_start, ev_global);
const int nthreads = tc;
acc_t oebond, ov0, ov1, ov2, ov3, ov4, ov5;
if (EVFLAG) {
if (EFLAG)
oebond = (acc_t)0.0;
if (vflag) {
ov0 = ov1 = ov2 = ov3 = ov4 = ov5 = (acc_t)0.0;
}
}
#if defined(_OPENMP)
#pragma omp parallel default(none) \
shared(f_start,f_stride,fc) \
reduction(+:oebond,ov0,ov1,ov2,ov3,ov4,ov5)
#endif
{
int nfrom, nto, tid;
IP_PRE_omp_range_id(nfrom, nto, tid, inum, nthreads);
FORCE_T * _noalias const f = f_start + (tid * f_stride);
if (fix->need_zero(tid))
memset(f, 0, f_stride * sizeof(FORCE_T));
const int3_t * _noalias const bondlist =
(int3_t *) neighbor->bondlist[0];
for (int n = nfrom; n < nto; n++) {
const int i1 = bondlist[n].a;
const int i2 = bondlist[n].b;
const int type = bondlist[n].t;
const flt_t delx = x[i1].x - x[i2].x;
const flt_t dely = x[i1].y - x[i2].y;
const flt_t delz = x[i1].z - x[i2].z;
const flt_t rsq = delx*delx + dely*dely + delz*delz;
const flt_t r = sqrt(rsq);
const flt_t dr = r - fc.fc[type].r0;
const flt_t rk = fc.fc[type].k * dr;
// force & energy
flt_t fbond;
if (r > (flt_t)0.0) fbond = (flt_t)-2.0*rk/r;
else fbond = (flt_t)0.0;
flt_t ebond;
if (EFLAG) ebond = rk*dr;
// apply force to each of 2 atoms
if (NEWTON_BOND || i1 < nlocal) {
f[i1].x += delx*fbond;
f[i1].y += dely*fbond;
f[i1].z += delz*fbond;
}
if (NEWTON_BOND || i2 < nlocal) {
f[i2].x -= delx*fbond;
f[i2].y -= dely*fbond;
f[i2].z -= delz*fbond;
}
if (EVFLAG) {
IP_PRE_ev_tally_bond(EFLAG, eatom, vflag, ebond, i1, i2, fbond,
delx, dely, delz, oebond, f, NEWTON_BOND,
nlocal, ov0, ov1, ov2, ov3, ov4, ov5);
}
} // for n
} // omp parallel
if (EVFLAG) {
if (EFLAG)
energy += oebond;
if (vflag) {
virial[0] += ov0; virial[1] += ov1; virial[2] += ov2;
virial[3] += ov3; virial[4] += ov4; virial[5] += ov5;
}
}
fix->set_reduce_flag();
}
/* ---------------------------------------------------------------------- */
void BondHarmonicIntel::init_style()
{
BondHarmonic::init_style();
int ifix = modify->find_fix("package_intel");
if (ifix < 0)
error->all(FLERR,
"The 'package intel' command is required for /intel styles");
fix = static_cast<FixIntel *>(modify->fix[ifix]);
#ifdef _LMP_INTEL_OFFLOAD
_use_base = 0;
if (fix->offload_balance() != 0.0) {
_use_base = 1;
return;
}
#endif
fix->bond_init_check();
if (fix->precision() == FixIntel::PREC_MODE_MIXED)
pack_force_const(force_const_single, fix->get_mixed_buffers());
else if (fix->precision() == FixIntel::PREC_MODE_DOUBLE)
pack_force_const(force_const_double, fix->get_double_buffers());
else
pack_force_const(force_const_single, fix->get_single_buffers());
}
/* ---------------------------------------------------------------------- */
template <class flt_t, class acc_t>
void BondHarmonicIntel::pack_force_const(ForceConst<flt_t> &fc,
IntelBuffers<flt_t,acc_t> *buffers)
{
const int bp1 = atom->nbondtypes + 1;
fc.set_ntypes(bp1,memory);
for (int i = 0; i < bp1; i++) {
fc.fc[i].k = k[i];
fc.fc[i].r0 = r0[i];
}
}
/* ---------------------------------------------------------------------- */
template <class flt_t>
void BondHarmonicIntel::ForceConst<flt_t>::set_ntypes(const int nbondtypes,
Memory *memory) {
if (nbondtypes != _nbondtypes) {
if (_nbondtypes > 0)
_memory->destroy(fc);
if (nbondtypes > 0)
_memory->create(fc,nbondtypes,"bondharmonicintel.fc");
}
_nbondtypes = nbondtypes;
_memory = memory;
}
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