/*
* Copyright 1997, Regents of the University of Minnesota
*
* mkwayrefine.c
*
* This file contains the driving routines for multilevel k-way refinement
*
* Started 7/28/97
* George
*
* $Id: mkwayrefine.c,v 1.2 1998/11/27 18:16:19 karypis Exp $
*/
#include <metis.h>
/*************************************************************************
* This function is the entry point of refinement
**************************************************************************/
void MocRefineKWayHorizontal(CtrlType *ctrl, GraphType *orggraph, GraphType *graph, long nparts,
float *ubvec)
{
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->UncoarsenTmr));
/* Compute the parameters of the coarsest graph */
MocComputeKWayPartitionParams(ctrl, graph, nparts);
for (;;) {
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->RefTmr));
if (!MocIsHBalanced(graph->ncon, nparts, graph->npwgts, ubvec)) {
MocComputeKWayBalanceBoundary(ctrl, graph, nparts);
MCGreedy_KWayEdgeBalanceHorizontal(ctrl, graph, nparts, ubvec, 4);
ComputeKWayBoundary(ctrl, graph, nparts);
}
MCRandom_KWayEdgeRefineHorizontal(ctrl, graph, nparts, ubvec, 10);
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->RefTmr));
if (graph == orggraph)
break;
graph = graph->finer;
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->ProjectTmr));
MocProjectKWayPartition(ctrl, graph, nparts);
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->ProjectTmr));
}
if (!MocIsHBalanced(graph->ncon, nparts, graph->npwgts, ubvec)) {
MocComputeKWayBalanceBoundary(ctrl, graph, nparts);
MCGreedy_KWayEdgeBalanceHorizontal(ctrl, graph, nparts, ubvec, 4);
ComputeKWayBoundary(ctrl, graph, nparts);
MCRandom_KWayEdgeRefineHorizontal(ctrl, graph, nparts, ubvec, 10);
}
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->UncoarsenTmr));
}
/*************************************************************************
* This function allocates memory for k-way edge refinement
**************************************************************************/
void MocAllocateKWayPartitionMemory(CtrlType *ctrl, GraphType *graph, long nparts)
{
long nvtxs, ncon, pad64;
nvtxs = graph->nvtxs;
ncon = graph->ncon;
pad64 = (3*nvtxs)%2;
graph->rdata = idxmalloc(3*nvtxs+(sizeof(RInfoType)/sizeof(idxtype))*nvtxs+pad64, "AllocateKWayPartitionMemory: rdata");
graph->where = graph->rdata;
graph->bndptr = graph->rdata + nvtxs;
graph->bndind = graph->rdata + 2*nvtxs;
graph->rinfo = (RInfoType *)(graph->rdata + 3*nvtxs + pad64);
graph->npwgts = fmalloc(ncon*nparts, "MocAllocateKWayPartitionMemory: npwgts");
}
/*************************************************************************
* This function computes the initial id/ed
**************************************************************************/
void MocComputeKWayPartitionParams(CtrlType *ctrl, GraphType *graph, long nparts)
{
long i, j, k, l, nvtxs, ncon, nbnd, mincut, me, other;
idxtype *xadj, *adjncy, *adjwgt, *where, *bndind, *bndptr;
RInfoType *rinfo, *myrinfo;
EDegreeType *myedegrees;
float *nvwgt, *npwgts;
nvtxs = graph->nvtxs;
ncon = graph->ncon;
xadj = graph->xadj;
nvwgt = graph->nvwgt;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
where = graph->where;
npwgts = sset(ncon*nparts, 0.0, graph->npwgts);
bndind = graph->bndind;
bndptr = idxset(nvtxs, -1, graph->bndptr);
rinfo = graph->rinfo;
/*------------------------------------------------------------
/ Compute now the id/ed degrees
/------------------------------------------------------------*/
ctrl->wspace.cdegree = 0;
nbnd = mincut = 0;
for (i=0; i<nvtxs; i++) {
me = where[i];
saxpy(ncon, 1.0, nvwgt+i*ncon, 1, npwgts+me*ncon, 1);
myrinfo = rinfo+i;
myrinfo->id = myrinfo->ed = myrinfo->ndegrees = 0;
myrinfo->edegrees = NULL;
for (j=xadj[i]; j<xadj[i+1]; j++) {
if (me != where[adjncy[j]])
myrinfo->ed += adjwgt[j];
}
myrinfo->id = graph->adjwgtsum[i] - myrinfo->ed;
if (myrinfo->ed > 0)
mincut += myrinfo->ed;
if (myrinfo->ed-myrinfo->id >= 0)
BNDInsert(nbnd, bndind, bndptr, i);
/* Time to compute the particular external degrees */
if (myrinfo->ed > 0) {
myedegrees = myrinfo->edegrees = ctrl->wspace.edegrees+ctrl->wspace.cdegree;
ctrl->wspace.cdegree += xadj[i+1]-xadj[i];
for (j=xadj[i]; j<xadj[i+1]; j++) {
other = where[adjncy[j]];
if (me != other) {
for (k=0; k<myrinfo->ndegrees; k++) {
if (myedegrees[k].pid == other) {
myedegrees[k].ed += adjwgt[j];
break;
}
}
if (k == myrinfo->ndegrees) {
myedegrees[myrinfo->ndegrees].pid = other;
myedegrees[myrinfo->ndegrees++].ed = adjwgt[j];
}
}
}
ASSERT(myrinfo->ndegrees <= xadj[i+1]-xadj[i]);
}
}
graph->mincut = mincut/2;
graph->nbnd = nbnd;
}
/*************************************************************************
* This function projects a partition, and at the same time computes the
* parameters for refinement.
**************************************************************************/
void MocProjectKWayPartition(CtrlType *ctrl, GraphType *graph, long nparts)
{
long i, j, k, nvtxs, nbnd, me, other, istart, iend, ndegrees;
idxtype *xadj, *adjncy, *adjwgt, *adjwgtsum;
idxtype *cmap, *where, *bndptr, *bndind;
idxtype *cwhere;
GraphType *cgraph;
RInfoType *crinfo, *rinfo, *myrinfo;
EDegreeType *myedegrees;
idxtype *htable;
cgraph = graph->coarser;
cwhere = cgraph->where;
crinfo = cgraph->rinfo;
nvtxs = graph->nvtxs;
cmap = graph->cmap;
xadj = graph->xadj;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
adjwgtsum = graph->adjwgtsum;
MocAllocateKWayPartitionMemory(ctrl, graph, nparts);
where = graph->where;
rinfo = graph->rinfo;
bndind = graph->bndind;
bndptr = idxset(nvtxs, -1, graph->bndptr);
/* Go through and project partition and compute id/ed for the nodes */
for (i=0; i<nvtxs; i++) {
k = cmap[i];
where[i] = cwhere[k];
cmap[i] = crinfo[k].ed; /* For optimization */
}
htable = idxset(nparts, -1, idxwspacemalloc(ctrl, nparts));
ctrl->wspace.cdegree = 0;
for (nbnd=0, i=0; i<nvtxs; i++) {
me = where[i];
myrinfo = rinfo+i;
myrinfo->id = myrinfo->ed = myrinfo->ndegrees = 0;
myrinfo->edegrees = NULL;
myrinfo->id = adjwgtsum[i];
if (cmap[i] > 0) { /* If it is an interface node. Note cmap[i] = crinfo[cmap[i]].ed */
istart = xadj[i];
iend = xadj[i+1];
myedegrees = myrinfo->edegrees = ctrl->wspace.edegrees+ctrl->wspace.cdegree;
ctrl->wspace.cdegree += iend-istart;
ndegrees = 0;
for (j=istart; j<iend; j++) {
other = where[adjncy[j]];
if (me != other) {
myrinfo->ed += adjwgt[j];
if ((k = htable[other]) == -1) {
htable[other] = ndegrees;
myedegrees[ndegrees].pid = other;
myedegrees[ndegrees++].ed = adjwgt[j];
}
else {
myedegrees[k].ed += adjwgt[j];
}
}
}
myrinfo->id -= myrinfo->ed;
/* Remove space for edegrees if it was interior */
if (myrinfo->ed == 0) {
myrinfo->edegrees = NULL;
ctrl->wspace.cdegree -= iend-istart;
}
else {
if (myrinfo->ed-myrinfo->id >= 0)
BNDInsert(nbnd, bndind, bndptr, i);
myrinfo->ndegrees = ndegrees;
for (j=0; j<ndegrees; j++)
htable[myedegrees[j].pid] = -1;
}
}
}
scopy(graph->ncon*nparts, cgraph->npwgts, graph->npwgts);
graph->mincut = cgraph->mincut;
graph->nbnd = nbnd;
FreeGraph(graph->coarser);
graph->coarser = NULL;
idxwspacefree(ctrl, nparts);
ASSERT(CheckBnd2(graph));
}
/*************************************************************************
* This function computes the boundary definition for balancing
**************************************************************************/
void MocComputeKWayBalanceBoundary(CtrlType *ctrl, GraphType *graph, long nparts)
{
long i, nvtxs, nbnd;
idxtype *bndind, *bndptr;
nvtxs = graph->nvtxs;
bndind = graph->bndind;
bndptr = idxset(nvtxs, -1, graph->bndptr);
/* Compute the new boundary */
nbnd = 0;
for (i=0; i<nvtxs; i++) {
if (graph->rinfo[i].ed > 0)
BNDInsert(nbnd, bndind, bndptr, i);
}
graph->nbnd = nbnd;
}
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