/*************************************************************************
* This function takes a graph and produces a bisection by using a region
* growing algorithm. The resulting partition is returned in
* graph->where
**************************************************************************/
void MocGrowBisection(CtrlType *ctrl, GraphType *graph, float *tpwgts, float ubfactor)
{
int i, j, k, nvtxs, ncon, from, bestcut, mincut, nbfs;
idxtype *bestwhere, *where;
nvtxs = graph->nvtxs;
MocAllocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere");
nbfs = 2*(nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS);
bestcut = idxsum(graph->nedges, graph->adjwgt);
for (; nbfs>0; nbfs--) {
idxset(nvtxs, 1, where);
where[RandomInRange(nvtxs)] = 0;
MocCompute2WayPartitionParams(ctrl, graph);
MocInit2WayBalance(ctrl, graph, tpwgts);
MocFM_2WayEdgeRefine(ctrl, graph, tpwgts, 4);
MocBalance2Way(ctrl, graph, tpwgts, 1.02);
MocFM_2WayEdgeRefine(ctrl, graph, tpwgts, 4);
if (bestcut >= graph->mincut) {
bestcut = graph->mincut;
idxcopy(nvtxs, where, bestwhere);
if (bestcut == 0)
break;
}
}
graph->mincut = bestcut;
idxcopy(nvtxs, bestwhere, where);
/*GKfree(&bestwhere, LTERM);*/
GKfree1((void**)&bestwhere);
}
/*************************************************************************
* This function performs multilevel bisection. It performs multiple
* bisections and selects the best.
**************************************************************************/
void MlevelNodeBisectionMultiple(CtrlType *ctrl, GraphType *graph, int *tpwgts, float ubfactor)
{
int i, nvtxs, cnvtxs, mincut, tmp;
GraphType *cgraph;
idxtype *bestwhere;
if (ctrl->nseps == 1 || graph->nvtxs < (ctrl->oflags&OFLAG_COMPRESS ? 1000 : 2000)) {
MlevelNodeBisection(ctrl, graph, tpwgts, ubfactor);
return;
}
nvtxs = graph->nvtxs;
if (ctrl->oflags&OFLAG_COMPRESS) { /* Multiple separators at the original graph */
bestwhere = idxmalloc(nvtxs, "MlevelNodeBisection2: bestwhere");
mincut = nvtxs;
for (i=ctrl->nseps; i>0; i--) {
MlevelNodeBisection(ctrl, graph, tpwgts, ubfactor);
/* printf("%5d ", cgraph->mincut); */
if (graph->mincut < mincut) {
mincut = graph->mincut;
idxcopy(nvtxs, graph->where, bestwhere);
}
/*GKfree(&graph->rdata, LTERM);*/
GKfree1((void**)&graph->rdata);
if (mincut == 0)
break;
}
/* printf("[%5d]\n", mincut); */
Allocate2WayNodePartitionMemory(ctrl, graph);
idxcopy(nvtxs, bestwhere, graph->where);
free(bestwhere);
Compute2WayNodePartitionParams(ctrl, graph);
}
else { /* Coarsen it a bit */
ctrl->CoarsenTo = nvtxs-1;
cgraph = Coarsen2Way(ctrl, graph);
cnvtxs = cgraph->nvtxs;
bestwhere = idxmalloc(cnvtxs, "MlevelNodeBisection2: bestwhere");
mincut = nvtxs;
for (i=ctrl->nseps; i>0; i--) {
ctrl->CType += 20; /* This is a hack. Look at coarsen.c */
MlevelNodeBisection(ctrl, cgraph, tpwgts, ubfactor);
/* printf("%5d ", cgraph->mincut); */
if (cgraph->mincut < mincut) {
mincut = cgraph->mincut;
idxcopy(cnvtxs, cgraph->where, bestwhere);
}
/*GKfree(&cgraph->rdata, LTERM);*/
GKfree1((void **)&cgraph->rdata);
if (mincut == 0)
break;
}
/* printf("[%5d]\n", mincut); */
Allocate2WayNodePartitionMemory(ctrl, cgraph);
idxcopy(cnvtxs, bestwhere, cgraph->where);
free(bestwhere);
Compute2WayNodePartitionParams(ctrl, cgraph);
Refine2WayNode(ctrl, graph, cgraph, ubfactor);
}
}
/*************************************************************************
* This function is the entry point for ONCMETIS
**************************************************************************/
void METIS_NodeND(int *nvtxs, idxtype *xadj, idxtype *adjncy, int *numflag, int *options,
idxtype *perm, idxtype *iperm)
{
int i, ii, j, l, wflag, nflag;
GraphType graph;
CtrlType ctrl;
idxtype *cptr, *cind, *piperm;
if (*numflag == 1)
Change2CNumbering(*nvtxs, xadj, adjncy);
if (options[0] == 0) { /* Use the default parameters */
ctrl.CType = ONMETIS_CTYPE;
ctrl.IType = ONMETIS_ITYPE;
ctrl.RType = ONMETIS_RTYPE;
ctrl.dbglvl = ONMETIS_DBGLVL;
ctrl.oflags = ONMETIS_OFLAGS;
ctrl.pfactor = ONMETIS_PFACTOR;
ctrl.nseps = ONMETIS_NSEPS;
}
else {
ctrl.CType = options[OPTION_CTYPE];
ctrl.IType = options[OPTION_ITYPE];
ctrl.RType = options[OPTION_RTYPE];
ctrl.dbglvl = options[OPTION_DBGLVL];
ctrl.oflags = options[OPTION_OFLAGS];
ctrl.pfactor = options[OPTION_PFACTOR];
ctrl.nseps = options[OPTION_NSEPS];
}
if (ctrl.nseps < 1)
ctrl.nseps = 1;
ctrl.optype = OP_ONMETIS;
ctrl.CoarsenTo = 100;
IFSET(ctrl.dbglvl, DBG_TIME, InitTimers(&ctrl));
IFSET(ctrl.dbglvl, DBG_TIME, starttimer(ctrl.TotalTmr));
InitRandom(-1);
if (ctrl.pfactor > 0) {
/*============================================================
* Prune the dense columns
==============================================================*/
piperm = idxmalloc(*nvtxs, "ONMETIS: piperm");
PruneGraph(&ctrl, &graph, *nvtxs, xadj, adjncy, piperm, (float)(0.1*ctrl.pfactor));
}
else if (ctrl.oflags&OFLAG_COMPRESS) {
/*============================================================
* Compress the graph
==============================================================*/
cptr = idxmalloc(*nvtxs+1, "ONMETIS: cptr");
cind = idxmalloc(*nvtxs, "ONMETIS: cind");
CompressGraph(&ctrl, &graph, *nvtxs, xadj, adjncy, cptr, cind);
if (graph.nvtxs >= COMPRESSION_FRACTION*(*nvtxs)) {
ctrl.oflags--; /* We actually performed no compression */
/*GKfree(&cptr, &cind, LTERM);*/
GKfree2((void **)&cptr, (void **)&cind);
}
else if (2*graph.nvtxs < *nvtxs && ctrl.nseps == 1)
ctrl.nseps = 2;
}
else {
SetUpGraph(&graph, OP_ONMETIS, *nvtxs, 1, xadj, adjncy, NULL, NULL, 0);
}
/*=============================================================
* Do the nested dissection ordering
--=============================================================*/
ctrl.maxvwgt = 1.5*(idxsum(graph.nvtxs, graph.vwgt)/ctrl.CoarsenTo);
AllocateWorkSpace(&ctrl, &graph, 2);
if (ctrl.oflags&OFLAG_CCMP)
MlevelNestedDissectionCC(&ctrl, &graph, iperm, ORDER_UNBALANCE_FRACTION, graph.nvtxs);
else
MlevelNestedDissection(&ctrl, &graph, iperm, ORDER_UNBALANCE_FRACTION, graph.nvtxs);
FreeWorkSpace(&ctrl, &graph);
if (ctrl.pfactor > 0) { /* Order any prunned vertices */
if (graph.nvtxs < *nvtxs) {
idxcopy(graph.nvtxs, iperm, perm); /* Use perm as an auxiliary array */
for (i=0; i<graph.nvtxs; i++)
iperm[piperm[i]] = perm[i];
for (i=graph.nvtxs; i<*nvtxs; i++)
iperm[piperm[i]] = i;
}
/*GKfree(&piperm, LTERM); */
GKfree1((void **)&piperm);
}
else if (ctrl.oflags&OFLAG_COMPRESS) { /* Uncompress the ordering */
if (graph.nvtxs < COMPRESSION_FRACTION*(*nvtxs)) {
/* construct perm from iperm */
for (i=0; i<graph.nvtxs; i++)
perm[iperm[i]] = i;
for (l=ii=0; ii<graph.nvtxs; ii++) {
i = perm[ii];
for (j=cptr[i]; j<cptr[i+1]; j++)
iperm[cind[j]] = l++;
}
}
/*GKfree(&cptr, &cind, LTERM);*/
GKfree2((void **)&cptr, (void **)&cind);
}
for (i=0; i<*nvtxs; i++)
perm[iperm[i]] = i;
IFSET(ctrl.dbglvl, DBG_TIME, stoptimer(ctrl.TotalTmr));
IFSET(ctrl.dbglvl, DBG_TIME, PrintTimers(&ctrl));
if (*numflag == 1)
Change2FNumberingOrder(*nvtxs, xadj, adjncy, perm, iperm);
}
/*************************************************************************
* This function is the entry point of refinement
**************************************************************************/
void RefineVolKWay(CtrlType *ctrl, GraphType *orggraph, GraphType *graph, int nparts,
float *tpwgts, float ubfactor)
{
int i, nlevels;
GraphType *ptr;
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->UncoarsenTmr));
/* Take care any non-contiguity */
if (ctrl->RType == RTYPE_KWAYRANDOM_MCONN) {
ComputeVolKWayPartitionParams(ctrl, graph, nparts);
EliminateVolComponents(ctrl, graph, nparts, tpwgts, 1.25);
EliminateVolSubDomainEdges(ctrl, graph, nparts, tpwgts);
EliminateVolComponents(ctrl, graph, nparts, tpwgts, 1.25);
}
/* Determine how many levels are there */
for (ptr=graph, nlevels=0; ptr!=orggraph; ptr=ptr->finer, nlevels++);
/* Compute the parameters of the coarsest graph */
ComputeVolKWayPartitionParams(ctrl, graph, nparts);
for (i=0; ;i++) {
/*PrintSubDomainGraph(graph, nparts, graph->where);*/
MALLOC_CHECK(NULL);
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->RefTmr));
if (2*i >= nlevels && !IsBalanced(graph->pwgts, nparts, tpwgts, 1.04*ubfactor)) {
ComputeVolKWayBalanceBoundary(ctrl, graph, nparts);
switch (ctrl->RType) {
case RTYPE_KWAYRANDOM:
Greedy_KWayVolBalance(ctrl, graph, nparts, tpwgts, ubfactor, 1);
break;
case RTYPE_KWAYRANDOM_MCONN:
Greedy_KWayVolBalanceMConn(ctrl, graph, nparts, tpwgts, ubfactor, 1);
break;
}
ComputeVolKWayBoundary(ctrl, graph, nparts);
}
switch (ctrl->RType) {
case RTYPE_KWAYRANDOM:
Random_KWayVolRefine(ctrl, graph, nparts, tpwgts, ubfactor, 10, 0);
break;
case RTYPE_KWAYRANDOM_MCONN:
Random_KWayVolRefineMConn(ctrl, graph, nparts, tpwgts, ubfactor, 10, 0);
break;
}
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->RefTmr));
if (graph == orggraph)
break;
/*GKfree(&graph->gdata, LTERM);*/ /* Deallocate the graph related arrays */
GKfree1((void**)&graph->gdata); /* Deallocate the graph related arrays */
graph = graph->finer;
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->ProjectTmr));
ProjectVolKWayPartition(ctrl, graph, nparts);
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->ProjectTmr));
}
if (!IsBalanced(graph->pwgts, nparts, tpwgts, ubfactor)) {
ComputeVolKWayBalanceBoundary(ctrl, graph, nparts);
switch (ctrl->RType) {
case RTYPE_KWAYRANDOM:
Greedy_KWayVolBalance(ctrl, graph, nparts, tpwgts, ubfactor, 8);
Random_KWayVolRefine(ctrl, graph, nparts, tpwgts, ubfactor, 10, 0);
break;
case RTYPE_KWAYRANDOM_MCONN:
Greedy_KWayVolBalanceMConn(ctrl, graph, nparts, tpwgts, ubfactor, 8);
Random_KWayVolRefineMConn(ctrl, graph, nparts, tpwgts, ubfactor, 10, 0);
break;
}
}
EliminateVolComponents(ctrl, graph, nparts, tpwgts, ubfactor);
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->UncoarsenTmr));
}
