void ComputeFillIn(graph_t *graph, idx_t *perm, idx_t *iperm,
size_t *r_maxlnz, size_t *r_opc)
{
idx_t i, j, k, nvtxs, maxlnz, maxsub;
idx_t *xadj, *adjncy;
idx_t *xlnz, *xnzsub, *nzsub;
size_t opc;
/*
printf("\nSymbolic factorization... --------------------------------------------\n");
*/
nvtxs = graph->nvtxs;
xadj = graph->xadj;
adjncy = graph->adjncy;
maxsub = 8*(nvtxs+xadj[nvtxs]);
/* Relabel the vertices so that it starts from 1 */
for (i=0; i<xadj[nvtxs]; i++)
adjncy[i]++;
for (i=0; i<nvtxs+1; i++)
xadj[i]++;
for (i=0; i<nvtxs; i++) {
iperm[i]++;
perm[i]++;
}
/* Allocate the required memory */
xlnz = imalloc(nvtxs+2, "ComputeFillIn: xlnz");
xnzsub = imalloc(nvtxs+2, "ComputeFillIn: xnzsub");
nzsub = imalloc(maxsub+1, "ComputeFillIn: nzsub");
/* Call sparspak's routine. */
if (smbfct(nvtxs, xadj, adjncy, perm, iperm, xlnz, &maxlnz, xnzsub, nzsub, &maxsub)) {
printf("Realocating nzsub...\n");
gk_free((void **)&nzsub, LTERM);
maxsub *= 2;
nzsub = imalloc(maxsub+1, "ComputeFillIn: nzsub");
if (smbfct(nvtxs, xadj, adjncy, perm, iperm, xlnz, &maxlnz, xnzsub, nzsub, &maxsub))
errexit("MAXSUB is too small!");
}
for (i=0; i<nvtxs; i++)
xlnz[i]--;
for (opc=0, i=0; i<nvtxs; i++)
opc += (xlnz[i+1]-xlnz[i])*(xlnz[i+1]-xlnz[i]) - (xlnz[i+1]-xlnz[i]);
*r_maxlnz = maxlnz;
*r_opc = opc;
gk_free((void **)&xlnz, &xnzsub, &nzsub, LTERM);
/* Relabel the vertices so that it starts from 0 */
for (i=0; i<nvtxs; i++) {
iperm[i]--;
perm[i]--;
}
for (i=0; i<nvtxs+1; i++)
xadj[i]--;
for (i=0; i<xadj[nvtxs]; i++)
adjncy[i]--;
}
/*************************************************************************
* This function sets up data structures for fill-in computations
**************************************************************************/
idxtype ComputeFillIn2(GraphType *graph, idxtype *iperm)
{
int i, j, k, nvtxs, maxlnz, maxsub;
idxtype *xadj, *adjncy;
idxtype *perm, *xlnz, *xnzsub, *nzsub;
double opc;
nvtxs = graph->nvtxs;
xadj = graph->xadj;
adjncy = graph->adjncy;
maxsub = 4*xadj[nvtxs];
/* Relabel the vertices so that it starts from 1 */
k = xadj[nvtxs];
for (i=0; i<k; i++)
adjncy[i]++;
for (i=0; i<nvtxs+1; i++)
xadj[i]++;
/* Allocate the required memory */
perm = idxmalloc(nvtxs+1, "ComputeFillIn: perm");
xlnz = idxmalloc(nvtxs+1, "ComputeFillIn: xlnz");
xnzsub = idxmalloc(nvtxs+1, "ComputeFillIn: xnzsub");
nzsub = idxmalloc(maxsub, "ComputeFillIn: nzsub");
/* Construct perm from iperm and change the numbering of iperm */
for (i=0; i<nvtxs; i++)
perm[iperm[i]] = i;
for (i=0; i<nvtxs; i++) {
iperm[i]++;
perm[i]++;
}
/*
* Call sparspak routine.
*/
if (smbfct(nvtxs, xadj, adjncy, perm, iperm, xlnz, &maxlnz, xnzsub, nzsub, &maxsub)) {
free(nzsub);
maxsub = 4*maxsub;
nzsub = idxmalloc(maxsub, "ComputeFillIn: nzsub");
if (smbfct(nvtxs, xadj, adjncy, perm, iperm, xlnz, &maxlnz, xnzsub, nzsub, &maxsub))
errexit("MAXSUB is too small!");
}
opc = 0;
for (i=0; i<nvtxs; i++)
xlnz[i]--;
for (i=0; i<nvtxs; i++)
opc += (xlnz[i+1]-xlnz[i])*(xlnz[i+1]-xlnz[i]) - (xlnz[i+1]-xlnz[i]);
GKfree(&perm, &xlnz, &xnzsub, &nzsub, LTERM);
/* Relabel the vertices so that it starts from 0 */
for (i=0; i<nvtxs; i++)
iperm[i]--;
for (i=0; i<nvtxs+1; i++)
xadj[i]--;
k = xadj[nvtxs];
for (i=0; i<k; i++)
adjncy[i]--;
return maxlnz;
}
