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lammps/src/USER-INTEL/dihedral_opls_intel.cpp
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dihedral_opls_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 "mpi.h"
#include "math.h"
#include "dihedral_opls_intel.h"
#include "atom.h"
#include "comm.h"
#include "memory.h"
#include "neighbor.h"
#include "domain.h"
#include "force.h"
#include "pair.h"
#include "update.h"
#include "error.h"
#include "suffix.h"
using namespace LAMMPS_NS;
#define PTOLERANCE (flt_t)1.05
#define MTOLERANCE (flt_t)-1.05
#define SMALL2 (flt_t)0.000001
#define INVSMALL (flt_t)1000.0
#define SMALLER2 (flt_t)0.0000000001
#define INVSMALLER (flt_t)100000.0
typedef struct { int a,b,c,d,t; } int5_t;
/* ---------------------------------------------------------------------- */
DihedralOPLSIntel::DihedralOPLSIntel(class LAMMPS *lmp)
: DihedralOPLS(lmp)
{
suffix_flag |= Suffix::INTEL;
}
/* ---------------------------------------------------------------------- */
void DihedralOPLSIntel::compute(int eflag, int vflag)
{
#ifdef _LMP_INTEL_OFFLOAD
if (_use_base) {
DihedralOPLS::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 DihedralOPLSIntel::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 DihedralOPLSIntel::eval(const int vflag,
IntelBuffers<flt_t,acc_t> *buffers,
const ForceConst<flt_t> &fc)
{
const int inum = neighbor->ndihedrallist;
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 oedihedral, ov0, ov1, ov2, ov3, ov4, ov5;
if (EVFLAG) {
if (EFLAG)
oedihedral = (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(+:oedihedral,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 int5_t * _noalias const dihedrallist =
(int5_t *) neighbor->dihedrallist[0];
acc_t sedihedral, sv0, sv1, sv2, sv3, sv4, sv5;
if (EVFLAG) {
if (EFLAG)
sedihedral = (acc_t)0.0;
if (vflag) {
sv0 = sv1 = sv2 = sv3 = sv4 = sv5 = (acc_t)0.0;
}
}
for (int n = nfrom; n < nto; n++) {
const int i1 = dihedrallist[n].a;
const int i2 = dihedrallist[n].b;
const int i3 = dihedrallist[n].c;
const int i4 = dihedrallist[n].d;
const int type = dihedrallist[n].t;
// 1st bond
const flt_t vb1x = x[i1].x - x[i2].x;
const flt_t vb1y = x[i1].y - x[i2].y;
const flt_t vb1z = x[i1].z - x[i2].z;
// 2nd bond
const flt_t vb2xm = x[i2].x - x[i3].x;
const flt_t vb2ym = x[i2].y - x[i3].y;
const flt_t vb2zm = x[i2].z - x[i3].z;
// 3rd bond
const flt_t vb3x = x[i4].x - x[i3].x;
const flt_t vb3y = x[i4].y - x[i3].y;
const flt_t vb3z = x[i4].z - x[i3].z;
// 1-4
const flt_t delx = x[i1].x - x[i4].x;
const flt_t dely = x[i1].y - x[i4].y;
const flt_t delz = x[i1].z - x[i4].z;
// c0 calculation
// 1st and 2nd angle
const flt_t b1mag2 = vb1x*vb1x + vb1y*vb1y + vb1z*vb1z;
const flt_t rb1 = (flt_t)1.0 / sqrt(b1mag2);
const flt_t sb1 = (flt_t)1.0 / b1mag2;
const flt_t b2mag2 = vb2xm*vb2xm + vb2ym*vb2ym + vb2zm*vb2zm;
const flt_t rb2 = (flt_t)1.0 / sqrt(b2mag2);
const flt_t sb2 = (flt_t)1.0 / b2mag2;
const flt_t b3mag2 = vb3x*vb3x + vb3y*vb3y + vb3z*vb3z;
const flt_t rb3 = (flt_t)1.0 / sqrt(b3mag2);
const flt_t sb3 = (flt_t)1.0 / b3mag2;
const flt_t c0 = (vb1x*vb3x + vb1y*vb3y + vb1z*vb3z) * rb1*rb3;
flt_t ctmp = -vb1x*vb2xm - vb1y*vb2ym - vb1z*vb2zm;
const flt_t r12c1 = rb1 * rb2;
const flt_t c1mag = ctmp * r12c1;
ctmp = vb2xm*vb3x + vb2ym*vb3y + vb2zm*vb3z;
const flt_t r12c2 = rb2 * rb3;
const flt_t c2mag = ctmp * r12c2;
// cos and sin of 2 angles and final c
flt_t sin2 = MAX((flt_t)1.0 - c1mag*c1mag,(flt_t)0.0);
flt_t sc1 = (flt_t)1.0/sqrt(sin2);
if (sin2 < SMALL2) sc1 = INVSMALL;
sin2 = MAX((flt_t)1.0 - c2mag*c2mag,(flt_t)0.0);
flt_t sc2 = (flt_t)1.0/sqrt(sin2);
if (sin2 < SMALL2) sc2 = INVSMALL;
const flt_t s1 = sc1 * sc1;
const flt_t s2 = sc2 * sc2;
flt_t s12 = sc1 * sc2;
flt_t c = (c0 + c1mag*c2mag) * s12;
const flt_t cx = vb1z*vb2ym - vb1y*vb2zm;
const flt_t cy = vb1x*vb2zm - vb1z*vb2xm;
const flt_t cz = vb1y*vb2xm - vb1x*vb2ym;
const flt_t cmag = (flt_t)1.0/sqrt(cx*cx + cy*cy + cz*cz);
const flt_t dx = (cx*vb3x + cy*vb3y + cz*vb3z)*cmag*rb3;
// error check
if (c > PTOLERANCE || c < MTOLERANCE) {
int me = comm->me;
if (screen) {
char str[128];
sprintf(str,"Dihedral problem: %d/%d " BIGINT_FORMAT " "
TAGINT_FORMAT " " TAGINT_FORMAT " "
TAGINT_FORMAT " " TAGINT_FORMAT,
me,tid,update->ntimestep,
atom->tag[i1],atom->tag[i2],atom->tag[i3],atom->tag[i4]);
error->warning(FLERR,str,0);
fprintf(screen," 1st atom: %d %g %g %g\n",
me,x[i1].x,x[i1].y,x[i1].z);
fprintf(screen," 2nd atom: %d %g %g %g\n",
me,x[i2].x,x[i2].y,x[i2].z);
fprintf(screen," 3rd atom: %d %g %g %g\n",
me,x[i3].x,x[i3].y,x[i3].z);
fprintf(screen," 4th atom: %d %g %g %g\n",
me,x[i4].x,x[i4].y,x[i4].z);
}
}
if (c > (flt_t)1.0) c = (flt_t)1.0;
if (c < (flt_t)-1.0) c = (flt_t)-1.0;
// force & energy
// p = sum (i=1,4) k_i * (1 + (-1)**(i+1)*cos(i*phi) )
// pd = dp/dc
const flt_t cossq = c * c;
const flt_t sinsq = (flt_t)1.0 - cossq;
flt_t siinv = (flt_t)1.0/sqrt(sinsq);
if (sinsq < SMALLER2 ) siinv = INVSMALLER;
if (dx < (flt_t)0.0) siinv = -siinv;
const flt_t cos_2phi = cossq - sinsq;
const flt_t sin_2phim = (flt_t)2.0 * c;
const flt_t cos_3phi = (flt_t)2.0 * c * cos_2phi - c;
const flt_t sin_3phim = (flt_t)2.0 * cos_2phi + (flt_t)1.0;
const flt_t cos_4phi = (flt_t)2.0 * cos_2phi * cos_2phi - (flt_t)1.0;
const flt_t sin_4phim = (flt_t)2.0 * cos_2phi * sin_2phim;
flt_t p, pd;
p = fc.bp[type].k1*((flt_t)1.0 + c) +
fc.bp[type].k2*((flt_t)1.0 - cos_2phi) +
fc.bp[type].k3*((flt_t)1.0 + cos_3phi) +
fc.bp[type].k4*((flt_t)1.0 - cos_4phi) ;
pd = fc.bp[type].k1 -
(flt_t)2.0 * fc.bp[type].k2 * sin_2phim +
(flt_t)3.0 * fc.bp[type].k3 * sin_3phim -
(flt_t)4.0 * fc.bp[type].k4 * sin_4phim;
flt_t edihed;
if (EFLAG) edihed = p;
const flt_t a = pd;
c = c * a;
s12 = s12 * a;
const flt_t a11 = c*sb1*s1;
const flt_t a22 = -sb2 * ((flt_t)2.0*c0*s12 - c*(s1+s2));
const flt_t a33 = c*sb3*s2;
const flt_t a12 = -r12c1 * (c1mag*c*s1 + c2mag*s12);
const flt_t a13 = -rb1*rb3*s12;
const flt_t a23 = r12c2 * (c2mag*c*s2 + c1mag*s12);
const flt_t sx2 = a12*vb1x - a22*vb2xm + a23*vb3x;
const flt_t sy2 = a12*vb1y - a22*vb2ym + a23*vb3y;
const flt_t sz2 = a12*vb1z - a22*vb2zm + a23*vb3z;
const flt_t f1x = a11*vb1x - a12*vb2xm + a13*vb3x;
const flt_t f1y = a11*vb1y - a12*vb2ym + a13*vb3y;
const flt_t f1z = a11*vb1z - a12*vb2zm + a13*vb3z;
const flt_t f2x = -sx2 - f1x;
const flt_t f2y = -sy2 - f1y;
const flt_t f2z = -sz2 - f1z;
const flt_t f4x = a13*vb1x - a23*vb2xm + a33*vb3x;
const flt_t f4y = a13*vb1y - a23*vb2ym + a33*vb3y;
const flt_t f4z = a13*vb1z - a23*vb2zm + a33*vb3z;
const flt_t f3x = sx2 - f4x;
const flt_t f3y = sy2 - f4y;
const flt_t f3z = sz2 - f4z;
if (EVFLAG) {
IP_PRE_ev_tally_dihed(EFLAG, eatom, vflag, edihed, i1, i2, i3, i4, f1x,
f1y, f1z, f3x, f3y, f3z, f4x, f4y, f4z, vb1x,
vb1y, vb1z, -vb2xm, -vb2ym, -vb2zm, vb3x, vb3y,
vb3z, sedihedral, f, NEWTON_BOND, nlocal,
sv0, sv1, sv2, sv3, sv4, sv5);
}
{
if (NEWTON_BOND || i1 < nlocal) {
f[i1].x += f1x;
f[i1].y += f1y;
f[i1].z += f1z;
}
if (NEWTON_BOND || i2 < nlocal) {
f[i2].x += f2x;
f[i2].y += f2y;
f[i2].z += f2z;
}
if (NEWTON_BOND || i3 < nlocal) {
f[i3].x += f3x;
f[i3].y += f3y;
f[i3].z += f3z;
}
if (NEWTON_BOND || i4 < nlocal) {
f[i4].x += f4x;
f[i4].y += f4y;
f[i4].z += f4z;
}
}
} // for n
if (EVFLAG) {
if (EFLAG) oedihedral += sedihedral;
if (vflag) {
ov0 += sv0; ov1 += sv1; ov2 += sv2; ov3 += sv3; ov4 += sv4; ov5 += sv5;
}
}
} // omp parallel
if (EVFLAG) {
if (EFLAG) energy += oedihedral;
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 DihedralOPLSIntel::init_style()
{
DihedralOPLS::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 DihedralOPLSIntel::pack_force_const(ForceConst<flt_t> &fc,
IntelBuffers<flt_t,acc_t> *buffers)
{
const int bp1 = atom->ndihedraltypes + 1;
fc.set_ntypes(bp1,memory);
for (int i = 0; i < bp1; i++) {
fc.bp[i].k1 = k1[i];
fc.bp[i].k2 = k2[i];
fc.bp[i].k3 = k3[i];
fc.bp[i].k4 = k4[i];
}
}
/* ---------------------------------------------------------------------- */
template <class flt_t>
void DihedralOPLSIntel::ForceConst<flt_t>::set_ntypes(const int nbondtypes,
Memory *memory) {
if (nbondtypes != _nbondtypes) {
if (_nbondtypes > 0)
_memory->destroy(bp);
if (nbondtypes > 0)
_memory->create(bp,nbondtypes,"dihedralcharmmintel.bp");
}
_nbondtypes = nbondtypes;
_memory = memory;
}
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