#include "pair_lj_expand_coul_long_gpu.h"
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include "atom.h"
#include "atom_vec.h"
#include "comm.h"
#include "force.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "integrate.h"
#include "memory.h"
#include "error.h"
#include "neigh_request.h"
#include "universe.h"
#include "update.h"
#include "domain.h"
#include "kspace.h"
#include "gpu_extra.h"
#define EWALD_F 1.12837917
#define EWALD_P 0.3275911
#define A1 0.254829592
#define A2 -0.284496736
#define A3 1.421413741
#define A4 -1.453152027
#define A5 1.061405429
using namespace LAMMPS_NS;
int ljecl_gpu_init(const int ntypes, double **cutsq, double **host_lj1,
double **host_lj2, double **host_lj3, double **host_lj4,
double **offset, double **shift, double *special_lj, const int nlocal,
const int nall, const int max_nbors, const int maxspecial,
const double cell_size, int &gpu_mode, FILE *screen,
double **host_cut_ljsq, double host_cut_coulsq,
double *host_special_coul, const double qqrd2e,
const double g_ewald);
int ljecl_gpu_reinit(const int ntypes, double **cutsq, double **host_lj1,
double **host_lj2, double **host_lj3, double **host_lj4,
double **offset, double **shift, double **host_lj_cutsq);
void ljecl_gpu_clear();
int ** ljecl_gpu_compute_n(const int ago, const int inum,
const int nall, double **host_x, int *host_type,
double *sublo, double *subhi, tagint *tag,
int **nspecial, tagint **special, const bool eflag,
const bool vflag, const bool eatom, const bool vatom,
int &host_start, int **ilist, int **jnum,
const double cpu_time, bool &success, double *host_q,
double *boxlo, double *prd);
void ljecl_gpu_compute(const int ago, const int inum, const int nall,
double **host_x, int *host_type, int *ilist, int *numj,
int **firstneigh, const bool eflag, const bool vflag,
const bool eatom, const bool vatom, int &host_start,
const double cpu_time, bool &success, double *host_q,
const int nlocal, double *boxlo, double *prd);
double ljecl_gpu_bytes();
PairLJExpandCoulLongGPU::PairLJExpandCoulLongGPU(LAMMPS *lmp) :
PairLJExpandCoulLong(lmp), gpu_mode(GPU_FORCE)
{
respa_enable = 0;
cpu_time = 0.0;
GPU_EXTRA::gpu_ready(lmp->modify, lmp->error);
}
PairLJExpandCoulLongGPU::~PairLJExpandCoulLongGPU()
{
ljecl_gpu_clear();
}
void PairLJExpandCoulLongGPU::compute(int eflag, int vflag)
{
ev_init(eflag,vflag);
int nall = atom->nlocal + atom->nghost;
int inum, host_start;
bool success = true;
int *ilist, *numneigh, **firstneigh;
if (gpu_mode != GPU_FORCE) {
inum = atom->nlocal;
firstneigh = ljecl_gpu_compute_n(neighbor->ago, inum, nall, atom->x,
atom->type, domain->sublo, domain->subhi,
atom->tag, atom->nspecial, atom->special,
eflag, vflag, eflag_atom, vflag_atom,
host_start, &ilist, &numneigh, cpu_time,
success, atom->q, domain->boxlo,
domain->prd);
} else {
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
ljecl_gpu_compute(neighbor->ago, inum, nall, atom->x, atom->type,
ilist, numneigh, firstneigh, eflag, vflag, eflag_atom,
vflag_atom, host_start, cpu_time, success, atom->q,
atom->nlocal, domain->boxlo, domain->prd);
}
if (!success)
error->one(FLERR,"Insufficient memory on accelerator");
if (host_start<inum) {
cpu_time = MPI_Wtime();
cpu_compute(host_start, inum, eflag, vflag, ilist, numneigh, firstneigh);
cpu_time = MPI_Wtime() - cpu_time;
}
}
void PairLJExpandCoulLongGPU::init_style()
{
cut_respa = NULL;
if (!atom->q_flag)
error->all(FLERR,"Pair style lj/cut/coul/long/gpu requires atom attribute q");
if (force->newton_pair)
error->all(FLERR,"Cannot use newton pair with lj/cut/coul/long/gpu pair style");
double maxcut = -1.0;
double cut;
for (int i = 1; i <= atom->ntypes; i++) {
for (int j = i; j <= atom->ntypes; j++) {
if (setflag[i][j] != 0 || (setflag[i][i] != 0 && setflag[j][j] != 0)) {
cut = init_one(i,j);
cut *= cut;
if (cut > maxcut)
maxcut = cut;
cutsq[i][j] = cutsq[j][i] = cut;
} else
cutsq[i][j] = cutsq[j][i] = 0.0;
}
}
double cell_size = sqrt(maxcut) + neighbor->skin;
cut_coulsq = cut_coul * cut_coul;
if (force->kspace == NULL)
error->all(FLERR,"Pair style requires a KSpace style");
g_ewald = force->kspace->g_ewald;
if (ncoultablebits) init_tables(cut_coul,cut_respa);
int maxspecial=0;
if (atom->molecular)
maxspecial=atom->maxspecial;
int success = ljecl_gpu_init(atom->ntypes+1, cutsq, lj1, lj2, lj3, lj4,
offset, shift, force->special_lj, atom->nlocal,
atom->nlocal+atom->nghost, 300, maxspecial,
cell_size, gpu_mode, screen, cut_ljsq, cut_coulsq,
force->special_coul, force->qqrd2e, g_ewald);
GPU_EXTRA::check_flag(success,error,world);
if (gpu_mode == GPU_FORCE) {
int irequest = neighbor->request(this,instance_me);
neighbor->requests[irequest]->half = 0;
neighbor->requests[irequest]->full = 1;
}
}
void PairLJExpandCoulLongGPU::reinit()
{
Pair::reinit();
ljecl_gpu_reinit(atom->ntypes+1, cutsq, lj1, lj2, lj3, lj4, offset, shift, cut_ljsq);
}
double PairLJExpandCoulLongGPU::memory_usage()
{
double bytes = Pair::memory_usage();
return bytes + ljecl_gpu_bytes();
}
void PairLJExpandCoulLongGPU::cpu_compute(int start, int inum, int eflag,
int , int *ilist,
int *numneigh, int **firstneigh)
{
int i,j,ii,jj,jnum,itype,jtype,itable;
double qtmp,xtmp,ytmp,ztmp,delx,dely,delz,evdwl,ecoul,fpair;
double fraction,table;
double r,r2inv,r6inv,forcecoul,forcelj,factor_coul,factor_lj;
double grij,expm2,prefactor,t,erfc;
double rsq,rshift,rshiftsq,rshift2inv;
int *jlist;
evdwl = ecoul = 0.0;
double **x = atom->x;
double **f = atom->f;
double *q = atom->q;
int *type = atom->type;
double *special_coul = force->special_coul;
double *special_lj = force->special_lj;
double qqrd2e = force->qqrd2e;
for (ii = start; ii < inum; ii++) {
i = ilist[ii];
qtmp = q[i];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
factor_lj = special_lj[sbmask(j)];
factor_coul = special_coul[sbmask(j)];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
jtype = type[j];
if (rsq < cutsq[itype][jtype]) {
r2inv = 1.0/rsq;
if (rsq < cut_coulsq) {
if (!ncoultablebits || rsq <= tabinnersq) {
r = sqrt(rsq);
grij = g_ewald * r;
expm2 = exp(-grij*grij);
t = 1.0 / (1.0 + EWALD_P*grij);
erfc = t * (A1+t*(A2+t*(A3+t*(A4+t*A5)))) * expm2;
prefactor = qqrd2e * qtmp*q[j]/r;
forcecoul = prefactor * (erfc + EWALD_F*grij*expm2);
if (factor_coul < 1.0) forcecoul -= (1.0-factor_coul)*prefactor;
} else {
union_int_float_t rsq_lookup;
rsq_lookup.f = rsq;
itable = rsq_lookup.i & ncoulmask;
itable >>= ncoulshiftbits;
fraction = (rsq_lookup.f - rtable[itable]) * drtable[itable];
table = ftable[itable] + fraction*dftable[itable];
forcecoul = qtmp*q[j] * table;
if (factor_coul < 1.0) {
table = ctable[itable] + fraction*dctable[itable];
prefactor = qtmp*q[j] * table;
forcecoul -= (1.0-factor_coul)*prefactor;
}
}
} else forcecoul = 0.0;
if (rsq < cut_ljsq[itype][jtype]) {
r = sqrt(rsq);
rshift = r - shift[itype][jtype];
rshiftsq = rshift*rshift;
rshift2inv = 1.0/rshiftsq;
r6inv = rshift2inv*rshift2inv*rshift2inv;
forcelj = r6inv * (lj1[itype][jtype]*r6inv - lj2[itype][jtype]);
forcelj = factor_lj*forcelj/rshift/r;
} else forcelj = 0.0;
fpair = forcecoul*r2inv + forcelj;
f[i][0] += delx*fpair;
f[i][1] += dely*fpair;
f[i][2] += delz*fpair;
if (eflag) {
if (rsq < cut_coulsq) {
if (!ncoultablebits || rsq <= tabinnersq)
ecoul = prefactor*erfc;
else {
table = etable[itable] + fraction*detable[itable];
ecoul = qtmp*q[j] * table;
}
if (factor_coul < 1.0) ecoul -= (1.0-factor_coul)*prefactor;
} else ecoul = 0.0;
if (rsq < cut_ljsq[itype][jtype]) {
evdwl = r6inv*(lj3[itype][jtype]*r6inv-lj4[itype][jtype]) -
offset[itype][jtype];
evdwl *= factor_lj;
} else evdwl = 0.0;
}
if (evflag) ev_tally_full(i,evdwl,ecoul,fpair,delx,dely,delz);
}
}
}
}