From 4eb08a5822c5470b914e4718278b5343df047635 Mon Sep 17 00:00:00 2001
From: Tim Mattox <timothy.mattox@engilitycorp.com>
Date: Tue, 17 Jan 2017 15:55:39 -0500
Subject: [PATCH] USER-DPD: Skip a0*stuff computations, if a0 was set to zero
in pair_coeff. This saves around 10% of the runtime for many of our tests
using SSA.
---
src/USER-DPD/pair_dpd_fdt_energy.cpp | 7 ++++++-
src/USER-DPD/pair_dpd_fdt_energy.h | 1 +
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/src/USER-DPD/pair_dpd_fdt_energy.cpp b/src/USER-DPD/pair_dpd_fdt_energy.cpp
index 558994d35e..569588b6fd 100644
--- a/src/USER-DPD/pair_dpd_fdt_energy.cpp
+++ b/src/USER-DPD/pair_dpd_fdt_energy.cpp
@@ -46,6 +46,7 @@ PairDPDfdtEnergy::PairDPDfdtEnergy(LAMMPS *lmp) : Pair(lmp)
duCond = NULL;
duMech = NULL;
splitFDT_flag = false;
+ a0_is_zero = false;
comm_reverse = 2;
}
@@ -110,7 +111,7 @@ void PairDPDfdtEnergy::compute(int eflag, int vflag)
// loop over neighbors of my atoms
if (splitFDT_flag) {
- for (ii = 0; ii < inum; ii++) {
+ if (!a0_is_zero) for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
@@ -373,6 +374,8 @@ void PairDPDfdtEnergy::coeff(int narg, char **arg)
double cut_one = cut_global;
double kappa_one;
+ a0_is_zero = (a0_one == 0.0); // Typical use with SSA is to set a0 to zero
+
kappa_one = force->numeric(FLERR,arg[4]);
if (narg == 6) cut_one = force->numeric(FLERR,arg[5]);
@@ -466,6 +469,7 @@ void PairDPDfdtEnergy::read_restart(FILE *fp)
allocate();
+ a0_is_zero = true; // start with assumption that a0 is zero
int i,j;
int me = comm->me;
for (i = 1; i <= atom->ntypes; i++)
@@ -483,6 +487,7 @@ void PairDPDfdtEnergy::read_restart(FILE *fp)
MPI_Bcast(&sigma[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&kappa[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&cut[i][j],1,MPI_DOUBLE,0,world);
+ a0_is_zero = a0_is_zero && (a0[i][j] == 0.0); // verify the zero assumption
}
}
}
diff --git a/src/USER-DPD/pair_dpd_fdt_energy.h b/src/USER-DPD/pair_dpd_fdt_energy.h
index 335beea7e3..84ab28aca4 100644
--- a/src/USER-DPD/pair_dpd_fdt_energy.h
+++ b/src/USER-DPD/pair_dpd_fdt_energy.h
@@ -52,6 +52,7 @@ class PairDPDfdtEnergy : public Pair {
double cut_global;
int seed;
bool splitFDT_flag;
+ bool a0_is_zero;
void allocate();
--
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