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adding optimization in tersoff

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Change-Id: I21d2bfe5181b3395430ec4b9949894c61b61587a
This commit is contained in:
Leopold Grinberg
2020-10-14 13:02:16 -05:00
committed by Nicholas Curtis
parent 9a48ae0c06
commit c25ccfdb98
2 changed files with 115 additions and 4 deletions
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109
src/KOKKOS/pair_tersoff_kokkos.cpp
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@ -379,8 +379,15 @@ void PairTersoffKokkos<DeviceType>::operator()(TagPairTersoffComputeHalf<NEIGHFL
if (rsq > cutsq) continue;
const F_FLOAT r = sqrt(rsq);
#ifdef HIP_OPT_MERGE_FC_K_DFC
F_FLOAT tmp_fce, tmp_fcd;
ters_fc_k_and_ters_dfc(itype,jtype,jtype,r,tmp_fce,tmp_fcd);
#else
const F_FLOAT tmp_fce = ters_fc_k(itype,jtype,jtype,r);
const F_FLOAT tmp_fcd = ters_dfc(itype,jtype,jtype,r);
#endif
const F_FLOAT tmp_exp = exp(-paramskk(itype,jtype,jtype).lam1 * r);
const F_FLOAT frep = -paramskk(itype,jtype,jtype).biga * tmp_exp *
(tmp_fcd - tmp_fce*paramskk(itype,jtype,jtype).lam1) / r;
@ -437,10 +444,16 @@ void PairTersoffKokkos<DeviceType>::operator()(TagPairTersoffComputeHalf<NEIGHFL
const F_FLOAT fa = ters_fa_k(itype,jtype,jtype,rij);
const F_FLOAT dfa = ters_dfa(itype,jtype,jtype,rij);
#ifdef HIP_OPT_MERGE_BIJ_DBIJ
F_FLOAT bij, prefactor;
ters_bij_k_and_ters_dbij(itype,jtype,jtype,bo_ij, bij, prefactor);
const F_FLOAT fatt = -0.5*bij * dfa / rij;
prefactor = 0.5*fa * prefactor;
#else
const F_FLOAT bij = ters_bij_k(itype,jtype,jtype,bo_ij);
const F_FLOAT fatt = -0.5*bij * dfa / rij;
const F_FLOAT prefactor = 0.5*fa * ters_dbij(itype,jtype,jtype,bo_ij);
#endif
f_x += delx1*fatt;
f_y += dely1*fatt;
f_z += delz1*fatt;
@ -503,12 +516,18 @@ void PairTersoffKokkos<DeviceType>::operator()(TagPairTersoffComputeHalf<NEIGHFL
if ((itag+jtag) % 2 == 1) CONTINUE_FLAG=true;
} else {
if (x(j,2) < ztmp) CONTINUE_FLAG=true;
if (x(j,2) == ztmp && x(j,1) < ytmp) CONTINUE_FLAG=true;
if (x(j,2) == ztmp && x(j,1) == ytmp && x(j,0) < xtmp) CONTINUE_FLAG=true;
else if (x(j,2) == ztmp && x(j,1) < ytmp) CONTINUE_FLAG=true;
else if (x(j,2) == ztmp && x(j,1) == ytmp && x(j,0) < xtmp) CONTINUE_FLAG=true;
}
if (CONTINUE_FLAG != true){
#ifdef HIP_OPT_MERGE_FC_K_DFC
F_FLOAT tmp_fce, tmp_fcd;
ters_fc_k_and_ters_dfc(itype,jtype,jtype,rij,tmp_fce,tmp_fcd);
#else
const F_FLOAT tmp_fce = ters_fc_k(itype,jtype,jtype,rij);
const F_FLOAT tmp_fcd = ters_dfc(itype,jtype,jtype,rij);
#endif
const F_FLOAT tmp_exp = exp(-paramskk(itype,jtype,jtype).lam1 * rij);
const F_FLOAT frep = -paramskk(itype,jtype,jtype).biga * tmp_exp *
(tmp_fcd - tmp_fce*paramskk(itype,jtype,jtype).lam1) / rij;
@ -869,6 +888,41 @@ double PairTersoffKokkos<DeviceType>::ters_dfc(const int &i, const int &j,
/* ---------------------------------------------------------------------- */
#ifdef HIP_OPT_MERGE_FC_K_DFC
template<class DeviceType>
KOKKOS_INLINE_FUNCTION
void PairTersoffKokkos<DeviceType>::ters_fc_k_and_ters_dfc(const int &i, const int &j,
const int &k, const F_FLOAT &r, double& result1, double& result2) const
{
const F_FLOAT ters_R = paramskk(i,j,k).bigr;
const F_FLOAT ters_D = paramskk(i,j,k).bigd;
if (r < ters_R-ters_D){
result1 = 1.0;
result2 = 0.0;
return;
}
if (r > ters_R+ters_D){
result1 = 0.0;
result2 = 0.0;
return;
}
const F_FLOAT arg = MY_PI2*(r - ters_R)/ters_D;
//double sn, cn;
//sincos(arg, &sn, &cn);
result1 = 0.5*(1.0 - sin(arg));
result2 = -(MY_PI4/ters_D) * cos(arg);
return;
}
#endif
/* ---------------------------------------------------------------------- */
template<class DeviceType>
KOKKOS_INLINE_FUNCTION
double PairTersoffKokkos<DeviceType>::bondorder(const int &i, const int &j, const int &k,
@ -970,7 +1024,7 @@ double PairTersoffKokkos<DeviceType>::ters_dbij(const int &i, const int &j,
const F_FLOAT tmp = paramskk(i,j,k).beta * bo;
if (tmp > paramskk(i,j,k).c1) return paramskk(i,j,k).beta * -0.5/sqrt(tmp*tmp);//*pow(tmp,-1.5);
if (tmp > paramskk(i,j,k).c2)
return paramskk(i,j,k).beta * (-0.5/sqrt(tmp*tmp) * //*pow(tmp,-1.5) *
return paramskk(i,j,k).beta * (-0.5/sqrt(tmp*tmp) * //*pow(tmp,-1.5) * //LG why ro compute sqrt(tmp^2) ?
(1.0 - 0.5*(1.0 + 1.0/(2.0*paramskk(i,j,k).powern)) *
pow(tmp,-paramskk(i,j,k).powern)));
if (tmp < paramskk(i,j,k).c4) return 0.0;
@ -983,6 +1037,53 @@ double PairTersoffKokkos<DeviceType>::ters_dbij(const int &i, const int &j,
/* ---------------------------------------------------------------------- */
#ifdef HIP_OPT_MERGE_BIJ_DBIJ
template<class DeviceType>
KOKKOS_INLINE_FUNCTION
void PairTersoffKokkos<DeviceType>::ters_bij_k_and_ters_dbij(const int &i, const int &j,
const int &k, const F_FLOAT &bo, double& result1, double& result2) const
{
const F_FLOAT tmp = paramskk(i,j,k).beta * bo;
if (tmp > paramskk(i,j,k).c1){
result1 = 1.0/sqrt(tmp);
result2 = paramskk(i,j,k).beta * -0.5/fabs(tmp);//LG replacing 0.5/sqrt(tmp*tmp) by 0.5/fabs(tmp)
return;
}
auto prm_ijk_pn = paramskk(i,j,k).powern;
if (tmp > paramskk(i,j,k).c2){
auto tmp_pow_neg_prm_ijk_pn = pow(tmp,-prm_ijk_pn);
result1 = (1.0 - tmp_pow_neg_prm_ijk_pn / (2.0*prm_ijk_pn))/sqrt(tmp);
result2 = paramskk(i,j,k).beta * (-0.5/fabs(tmp) *
(1.0 - 0.5*(1.0 + 1.0/(2.0*prm_ijk_pn)) *
tmp_pow_neg_prm_ijk_pn));
return;
}
if (tmp < paramskk(i,j,k).c4) {
result1 = 1.0;
result2 = 0.0;
return;
}
if (tmp < paramskk(i,j,k).c3){
auto tmp_pow_prm_ijk_pn_less_one = pow(tmp,prm_ijk_pn-1.0);
result1 = 1.0 - tmp_pow_prm_ijk_pn_less_one*tmp/(2.0*prm_ijk_pn);
result2 = -0.5*paramskk(i,j,k).beta * tmp_pow_prm_ijk_pn_less_one;
return;
}
const F_FLOAT tmp_n = pow(tmp,paramskk(i,j,k).powern);
result1 = pow(1.0 + tmp_n, -1.0/(2.0*prm_ijk_pn));
result2 = -0.5 * pow(1.0+tmp_n, -1.0-(1.0/(2.0*prm_ijk_pn)))*tmp_n / bo;
}
#endif
template<class DeviceType>
KOKKOS_INLINE_FUNCTION
void PairTersoffKokkos<DeviceType>::ters_dthb(

10
src/KOKKOS/pair_tersoff_kokkos.h
View File

@ -87,6 +87,11 @@ class PairTersoffKokkos : public PairTersoff {
KOKKOS_INLINE_FUNCTION
double ters_dfc(const int &i, const int &j, const int &k, const F_FLOAT &r) const;
#ifdef HIP_OPT_MERGE_FC_K_DFC
KOKKOS_INLINE_FUNCTION
void ters_fc_k_and_ters_dfc(const int &i, const int &j, const int &k, const F_FLOAT &r, double &result1, double &result2) const;
#endif
KOKKOS_INLINE_FUNCTION
double ters_fa_k(const int &i, const int &j, const int &k, const F_FLOAT &r) const;
@ -99,6 +104,11 @@ class PairTersoffKokkos : public PairTersoff {
KOKKOS_INLINE_FUNCTION
double ters_dbij(const int &i, const int &j, const int &k, const F_FLOAT &bo) const;
#ifdef HIP_OPT_MERGE_BIJ_DBIJ
KOKKOS_INLINE_FUNCTION
void ters_bij_k_and_ters_dbij(const int &i, const int &j, const int &k, const F_FLOAT &bo, double &result1, double &result2) const;
#endif
KOKKOS_INLINE_FUNCTION
double bondorder(const int &i, const int &j, const int &k,
const F_FLOAT &rij, const F_FLOAT &dx1, const F_FLOAT &dy1, const F_FLOAT &dz1,