matrix_repart.c

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/*****************************************************************************
 * Copyright (c) 2019 FrontISTR Commons
 * This software is released under the MIT License, see LICENSE.txt
 *****************************************************************************/
 
#include <stdio.h>
#include <stdlib.h>
#include "hecmw_util.h"
 
#ifdef HECMW_WITH_METIS
#include "metis.h"
#endif
 
#include "matrix2graph.h"
#include "separator.h"
Separator_result *separator;
 
void bi_part_directive(int *neqns, int *nttbr, int *irow, int *jcol,
                       int *num_graph1, int *num_graph2, int *num_separator) {
#ifdef HECMW_WITH_METIS
  graph_type *graph;
  int num_of_row, num_of_col, num_of_nzero;
 
  int *perm, *iperm;
 
  num_of_row   = *neqns;
  num_of_col   = *neqns;
  num_of_nzero = *nttbr;
 
  graph = (graph_type *)malloc(sizeof(graph_type));
  if (graph == NULL) separator_memory_exit("graph");
 
  fprintf(stderr, "Start transforming matrix to graph\n");
  matrix2graph(num_of_row, num_of_col, num_of_nzero, irow, jcol, graph);
  fprintf(stderr,
          "Graph Information "
          "---------------------------------------------------\n");
  fprintf(stderr, "#Vertices: %d, #Edges: %d\n\n", graph->nvtxs,
          graph->nedges / 2);
  perm  = (int *)calloc(num_of_col, sizeof(int));
  iperm = (int *)calloc(num_of_col, sizeof(int));
  if ((perm == NULL) || (iperm == NULL))
    separator_memory_exit("matrix_repart: perm, iperm");
 
  {
    /* The graph and the permutation are sized by the number of equations, so
     * they stay int; idx_t copies are needed only because METIS 5 takes them */
    idx_t options[METIS_NOPTIONS];
    idx_t nvtxs_metis = graph->nvtxs;
    idx_t *xadj_metis, *adjncy_metis, *perm_metis, *iperm_metis;
    int i;
 
    xadj_metis   = (idx_t *)calloc(num_of_col + 1, sizeof(idx_t));
    adjncy_metis = (idx_t *)calloc(graph->nedges, sizeof(idx_t));
    perm_metis   = (idx_t *)calloc(num_of_col, sizeof(idx_t));
    iperm_metis  = (idx_t *)calloc(num_of_col, sizeof(idx_t));
    if ((xadj_metis == NULL) || (adjncy_metis == NULL) ||
        (perm_metis == NULL) || (iperm_metis == NULL))
      separator_memory_exit("matrix_repart: metis arrays");
 
    for (i = 0; i <= num_of_col; i++) xadj_metis[i] = graph->xadj[i];
    for (i = 0; i < graph->nedges; i++) adjncy_metis[i] = graph->adjncy[i];
 
    METIS_SetDefaultOptions(options);
    options[METIS_OPTION_COMPRESS] = 0;
    METIS_NodeND(&nvtxs_metis, xadj_metis, adjncy_metis, NULL, options,
                 perm_metis, iperm_metis);
 
    for (i = 0; i < num_of_col; i++) {
      perm[i]  = (int)perm_metis[i];
      iperm[i] = (int)iperm_metis[i];
    }
 
    free(xadj_metis);
    free(adjncy_metis);
    free(perm_metis);
    free(iperm_metis);
  }
  /* copy to separator */
 
  *num_graph1    = separator->num_of_lgraph;
  *num_graph2    = separator->num_of_rgraph;
  *num_separator = separator->num_of_separator;
 
  free(perm);
  free(iperm);
  free(graph->xadj);
  free(graph->adjncy);
  free(graph);
 
#else
  fprintf(
      stderr,
      "Error: Direct Parallel Solver not available. Please install Metis.\n");
  HECMW_abort(HECMW_comm_get_comm());
#endif
 
  return;
}
 
void bi_part_directive_(int *neqns, int *nttbr, int *irow, int *jcol,
                        int *num_graph1, int *num_graph2, int *num_separator) {
  bi_part_directive(neqns, nttbr, irow, jcol, num_graph1, num_graph2,
                    num_separator);
}
 
void bi_part_directive__(int *neqns, int *nttbr, int *irow, int *jcol,
                         int *num_graph1, int *num_graph2, int *num_separator) {
  bi_part_directive(neqns, nttbr, irow, jcol, num_graph1, num_graph2,
                    num_separator);
}
 
void BI_PART_DIRECTIVE(int *neqns, int *nttbr, int *irow, int *jcol,
                       int *num_graph1, int *num_graph2, int *num_separator) {
  bi_part_directive(neqns, nttbr, irow, jcol, num_graph1, num_graph2,
                    num_separator);
}