gem5/splash2/codes/apps/water-nsquared/predcor.C
Sanchayan Maity 2fcc51c2c1 Commit splash2 benchmark
While at it also add the libpthread static library amd m5op_x86
for matrix multiplication test code as well.

Note that the splash2 benchmark code does not comply with gem5
coding guidelines. Academic guys never seem to follow 80 columns
and no whitespace guideline :(.
2017-04-26 20:50:15 +05:30

86 lines
3.2 KiB
C

/*************************************************************************/
/* */
/* Copyright (c) 1994 Stanford University */
/* */
/* All rights reserved. */
/* */
/* Permission is given to use, copy, and modify this software for any */
/* non-commercial purpose as long as this copyright notice is not */
/* removed. All other uses, including redistribution in whole or in */
/* part, are forbidden without prior written permission. */
/* */
/* This software is provided with absolutely no warranty and no */
/* support. */
/* */
/*************************************************************************/
EXTERN_ENV
#include "global.h"
#include "mddata.h"
#include "mdvar.h"
#include "parameters.h"
#include "split.h"
/* predicts new values for displacement and its five derivatives
*
* NOR1 : NOR1 = NORDER + 1 = 7 (for a sixth-order method)
*/
void PREDIC(double *C, long NOR1, long ProcID)
{
/* this routine calculates predicted F(X), F'(X), F''(X), ... */
long JIZ;
long JI;
long L;
double S;
long func, mol, dir, atom;
JIZ=2;
/* .....loop over F(X), F'(X), F''(X), ..... */
for (func = 0; func < NORDER; func++) {
for (mol = StartMol[ProcID]; mol < StartMol[ProcID+1]; mol++)
for ( dir = 0; dir < NDIR; dir++)
for ( atom = 0; atom < NATOM; atom++ ) {
JI = JIZ;
/* sum over Taylor Series */
S = 0.0;
for ( L = func; L < NORDER; L++) {
S += C[JI] * VAR[mol].F[L+1][dir][atom];
JI++;
} /* for */
VAR[mol].F[func][dir][atom] += S;
} /* for atom */
JIZ += NOR1;
} /* for func */
} /* end of subroutine PREDIC */
/* corrects the predicted values, based on forces etc. computed in the interim
*
* PCC : the predictor-corrector constants
* NOR1: NORDER + 1 = 7 for a sixth-order method)
*/
void CORREC(double *PCC, long NOR1, long ProcID)
{
/*
.....this routine calculates corrected F(X), F'(X), F"(X), ....
from corrected F(X) = predicted F(X) + PCC(1)*(FR-SD)
where SD is predicted accl. F"(X) and FR is computed
accl. (force/mass) at predicted position
*/
double Y;
long mol, dir, atom, func;
for (mol = StartMol[ProcID]; mol < StartMol[ProcID+1]; mol++) {
for (dir = 0; dir < NDIR; dir++) {
for (atom = 0; atom < NATOM; atom++) {
Y = VAR[mol].F[FORCES][dir][atom] - VAR[mol].F[ACC][dir][atom];
for ( func = 0; func < NOR1; func++)
VAR[mol].F[func][dir][atom] += PCC[func] * Y;
} /* for atom */
} /* for dir */
} /* for mol */
} /* end of subroutine CORREC */