nsz Git - libfirm/blob - heuristical.c

   1 /*
   2  * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief   Heuristic PBQP solver.
  23  * @date    02.10.2008
  24  * @author  Sebastian Buchwald
  25  * @version $Id$
  26  */
  27 #include "config.h"
  28
  29 #include "adt/array.h"
  30 #include "assert.h"
  31 #include "error.h"
  32
  33 #include "bucket.h"
  34 #include "heuristical.h"
  35 #include "optimal.h"
  36 #if     KAPS_DUMP
  37 #include "html_dumper.h"
  38 #endif
  39 #include "kaps.h"
  40 #include "matrix.h"
  41 #include "pbqp_edge.h"
  42 #include "pbqp_edge_t.h"
  43 #include "pbqp_node.h"
  44 #include "pbqp_node_t.h"
  45 #include "vector.h"
  46
  47 #include "timing.h"
  48
  49 static void apply_RN(pbqp *pbqp)
  50 {
  51         pbqp_node   *node         = NULL;
  52         unsigned     min_index    = 0;
  53
  54         assert(pbqp);
  55
  56         /* We want to reduce a node with maximum degree. */
  57         node = get_node_with_max_degree();
  58         assert(node);
  59         assert(pbqp_node_get_degree(node) > 2);
  60
  61 #if     KAPS_DUMP
  62         if (pbqp->dump_file) {
  63                 char     txt[100];
  64                 sprintf(txt, "RN-Reduction of Node n%d", node->index);
  65                 dump_section(pbqp->dump_file, 2, txt);
  66                 pbqp_dump_graph(pbqp);
  67         }
  68 #endif
  69
  70         min_index = get_local_minimal_alternative(pbqp, node);
  71
  72 #if     KAPS_DUMP
  73         if (pbqp->dump_file) {
  74                 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
  75                                         node->index, min_index);
  76         }
  77 #endif
  78
  79 #if KAPS_STATISTIC
  80         if (dump == 0) {
  81                 FILE *fh = fopen("solutions.pb", "a");
  82                 fprintf(fh, "[%u]", min_index);
  83                 fclose(fh);
  84                 pbqp->num_rn++;
  85         }
  86 #endif
  87
  88         /* Now that we found the local minimum set all other costs to infinity. */
  89         select_alternative(node, min_index);
  90 }
  91
  92 static void apply_heuristic_reductions(pbqp *pbqp)
  93 {
  94         for (;;) {
  95                 if (edge_bucket_get_length(edge_bucket) > 0) {
  96                         apply_edge(pbqp);
  97                 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
  98                         apply_RI(pbqp);
  99                 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
 100                         apply_RII(pbqp);
 101                 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
 102                         apply_RN(pbqp);
 103                 } else {
 104                         return;
 105                 }
 106         }
 107 }
 108
 109 void solve_pbqp_heuristical(pbqp *pbqp)
 110 {
 111         /* Reduce nodes degree ... */
 112         initial_simplify_edges(pbqp);
 113
 114         /* ... and put node into bucket representing their degree. */
 115         fill_node_buckets(pbqp);
 116
 117 #if KAPS_STATISTIC
 118         FILE *fh = fopen("solutions.pb", "a");
 119         fprintf(fh, "Solution");
 120         fclose(fh);
 121 #endif
 122
 123         apply_heuristic_reductions(pbqp);
 124
 125         pbqp->solution = determine_solution(pbqp);
 126
 127 #if KAPS_STATISTIC
 128         fh = fopen("solutions.pb", "a");
 129         fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RN/BF:%u\n", pbqp->solution,
 130                                 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
 131                                 pbqp->num_rn);
 132         fclose(fh);
 133 #endif
 134
 135         /* Solve reduced nodes. */
 136         back_propagate(pbqp);
 137
 138         free_buckets();
 139 }