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performance improvement through moving inlinable functions to header file

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This commit is contained in:
Axel Kohlmeyer
2017-06-30 13:04:09 -04:00
parent 5548704700
commit 9dad95d101
3 changed files with 137 additions and 131 deletions
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4
src/USER-MEAMC/README
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@ -1,6 +1,6 @@
This package implements the MEAM/C potential as a LAMMPS pair style.
+==============================================================================+
==============================================================================
This package is a translation of the MEAM package to native C++. See
that package as well as the Fortran code distributed in lib/meam for
@ -15,7 +15,7 @@ Translation by
The original Fortran implementation was created by
Greg Wagner (while at Sandia, now at Northwestern U).
+==============================================================================+
==============================================================================
Use "make yes-user-meamc" to enable this package when building LAMMPS.

77
src/USER-MEAMC/meam.h
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@ -110,11 +110,80 @@ public:
protected:
// meam_funcs.cpp
static double fcut(const double xi);
static double dfcut(const double xi, double &dfc);
static double dCfunc(const double rij2, const double rik2, const double rjk2);
static void dCfunc2(const double rij2, const double rik2, const double rjk2, double &dCikj1, double &dCikj2);
//-----------------------------------------------------------------------------
// Cutoff function
//
static double fcut(const double xi) {
double a;
if (xi >= 1.0)
return 1.0;
else if (xi <= 0.0)
return 0.0;
else {
a = 1.0 - xi;
a *= a; a *= a;
a = 1.0 - a;
return a * a;
}
}
//-----------------------------------------------------------------------------
// Cutoff function and derivative
//
static double dfcut(const double xi, double& dfc) {
double a, a3, a4, a1m4;
if (xi >= 1.0) {
dfc = 0.0;
return 1.0;
} else if (xi <= 0.0) {
dfc = 0.0;
return 0.0;
} else {
a = 1.0 - xi;
a3 = a * a * a;
a4 = a * a3;
a1m4 = 1.0-a4;
dfc = 8 * a1m4 * a3;
return a1m4*a1m4;
}
}
//-----------------------------------------------------------------------------
// Derivative of Cikj w.r.t. rij
// Inputs: rij,rij2,rik2,rjk2
//
static double dCfunc(const double rij2, const double rik2, const double rjk2) {
double rij4, a, asq, b,denom;
rij4 = rij2 * rij2;
a = rik2 - rjk2;
b = rik2 + rjk2;
asq = a*a;
denom = rij4 - asq;
denom = denom * denom;
return -4 * (-2 * rij2 * asq + rij4 * b + asq * b) / denom;
}
//-----------------------------------------------------------------------------
// Derivative of Cikj w.r.t. rik and rjk
// Inputs: rij,rij2,rik2,rjk2
//
static void dCfunc2(const double rij2, const double rik2, const double rjk2,
double& dCikj1, double& dCikj2) {
double rij4, rik4, rjk4, a, denom;
rij4 = rij2 * rij2;
rik4 = rik2 * rik2;
rjk4 = rjk2 * rjk2;
a = rik2 - rjk2;
denom = rij4 - a * a;
denom = denom * denom;
dCikj1 = 4 * rij2 * (rij4 + rik4 + 2 * rik2 * rjk2 - 3 * rjk4 - 2 * rij2 * a) / denom;
dCikj2 = 4 * rij2 * (rij4 - 3 * rik4 + 2 * rik2 * rjk2 + rjk4 + 2 * rij2 * a) / denom;
}
double G_gam(const double gamma, const int ibar, int &errorflag) const;
double dG_gam(const double gamma, const int ibar, double &dG) const;
static double zbl(const double r, const int z1, const int z2);

187
src/USER-MEAMC/meam_funcs.cpp
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@ -21,87 +21,6 @@
using namespace LAMMPS_NS;
//-----------------------------------------------------------------------------
// Cutoff function
//
double
MEAM::fcut(const double xi)
{
double a;
if (xi >= 1.0)
return 1.0;
else if (xi <= 0.0)
return 0.0;
else {
a = 1.0 - xi;
a = a * a;
a = a * a;
a = 1.0 - a;
return a * a;
// fc = xi
}
}
//-----------------------------------------------------------------------------
// Cutoff function and derivative
//
double
MEAM::dfcut(const double xi, double& dfc)
{
double a, a3, a4;
if (xi >= 1.0) {
dfc = 0.0;
return 1.0;
} else if (xi <= 0.0) {
dfc = 0.0;
return 0.0;
} else {
a = 1.0 - xi;
a3 = a * a * a;
a4 = a * a3;
dfc = 8 * (1.0 - a4) * a3;
return pow((1.0 - a4), 2);
// fc = xi
// dfc = 1.d0
}
}
//-----------------------------------------------------------------------------
// Derivative of Cikj w.r.t. rij
// Inputs: rij,rij2,rik2,rjk2
//
double
MEAM::dCfunc(const double rij2, const double rik2, const double rjk2)
{
double rij4, a, b, denom;
rij4 = rij2 * rij2;
a = rik2 - rjk2;
b = rik2 + rjk2;
denom = rij4 - a * a;
denom = denom * denom;
return -4 * (-2 * rij2 * a * a + rij4 * b + a * a * b) / denom;
}
//-----------------------------------------------------------------------------
// Derivative of Cikj w.r.t. rik and rjk
// Inputs: rij,rij2,rik2,rjk2
//
void
MEAM::dCfunc2(const double rij2, const double rik2, const double rjk2, double& dCikj1, double& dCikj2)
{
double rij4, rik4, rjk4, a, b, denom;
rij4 = rij2 * rij2;
rik4 = rik2 * rik2;
rjk4 = rjk2 * rjk2;
a = rik2 - rjk2;
b = rik2 + rjk2;
denom = rij4 - a * a;
denom = denom * denom;
dCikj1 = 4 * rij2 * (rij4 + rik4 + 2 * rik2 * rjk2 - 3 * rjk4 - 2 * rij2 * a) / denom;
dCikj2 = 4 * rij2 * (rij4 - 3 * rik4 + 2 * rik2 * rjk2 + rjk4 + 2 * rij2 * a) / denom;
}
//-----------------------------------------------------------------------------
// Compute G(gamma) based on selection flag ibar:
@ -142,6 +61,7 @@ MEAM::G_gam(const double gamma, const int ibar, int& errorflag) const
}
}
errorflag = 1;
return 0.0;
}
//-----------------------------------------------------------------------------
@ -195,6 +115,8 @@ MEAM::dG_gam(const double gamma, const int ibar, double& dG) const
return G;
}
}
dG = 1.0;
return 0.0;
}
//-----------------------------------------------------------------------------
@ -313,6 +235,7 @@ MEAM::get_Zij(const lattice_t latt)
return 8;
// call error('Lattice not defined in get_Zij.')
}
return 0;
}
//-----------------------------------------------------------------------------
@ -328,50 +251,64 @@ MEAM::get_Zij2(const lattice_t latt, const double cmin, const double cmax, doubl
int Zij2 = 0, numscr = 0;
switch (latt) {
case FCC:
Zij2 = 6;
a = sqrt(2.0);
numscr = 4;
break;
case BCC:
Zij2 = 6;
a = 2.0 / sqrt(3.0);
numscr = 4;
break;
case HCP:
Zij2 = 6;
a = sqrt(2.0);
numscr = 4;
break;
case B1:
Zij2 = 12;
a = sqrt(2.0);
numscr = 2;
break;
case DIA:
Zij2 = 0;
a = sqrt(8.0 / 3.0);
numscr = 4;
if (cmin < 0.500001) {
case FCC:
Zij2 = 6;
a = sqrt(2.0);
numscr = 4;
break;
case BCC:
Zij2 = 6;
a = 2.0 / sqrt(3.0);
numscr = 4;
break;
case HCP:
Zij2 = 6;
a = sqrt(2.0);
numscr = 4;
break;
case B1:
Zij2 = 12;
a = sqrt(2.0);
numscr = 2;
break;
case DIA:
Zij2 = 0;
a = sqrt(8.0 / 3.0);
numscr = 4;
if (cmin < 0.500001) {
// call error('can not do 2NN MEAM for dia')
}
break;
case DIM:
// this really shouldn't be allowed; make sure screening is zero
a = 1.0;
S = 0.0;
return 0;
case L12:
Zij2 = 6;
a = sqrt(2.0);
numscr = 4;
break;
case B2:
Zij2 = 6;
a = 2.0 / sqrt(3.0);
numscr = 4;
break;
// call error('Lattice not defined in get_Zij.')
}
break;
case DIM:
// this really shouldn't be allowed; make sure screening is zero
a = 1.0;
S = 0.0;
return 0;
case L12:
Zij2 = 6;
a = sqrt(2.0);
numscr = 4;
break;
case B2:
Zij2 = 6;
a = 2.0 / sqrt(3.0);
numscr = 4;
break;
case C11:
// unsupported lattice flag C11 in get_Zij
break;
default:
// unknown lattic flag in get Zij
// call error('Lattice not defined in get_Zij.')
break;
}
// Compute screening for each first neighbor
@ -379,6 +316,6 @@ MEAM::get_Zij2(const lattice_t latt, const double cmin, const double cmax, doubl
x = (C - cmin) / (cmax - cmin);
sijk = fcut(x);
// There are numscr first neighbors screening the second neighbors
S = pow(sijk, numscr);
S = MathSpecial::powint(sijk, numscr);
return Zij2;
}