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 "plist.h"
  48 #include "timing.h"
  49
  50 static void apply_heuristic_reductions(pbqp *pbqp)
  51 {
  52         for (;;) {
  53                 if (edge_bucket_get_length(edge_bucket) > 0) {
  54                         apply_edge(pbqp);
  55                 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
  56                         apply_RI(pbqp);
  57                 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
  58                         apply_RII(pbqp);
  59                 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
  60                         apply_RN(pbqp);
  61                 } else {
  62                         return;
  63                 }
  64         }
  65 }
  66
  67 void solve_pbqp_heuristical(pbqp *pbqp)
  68 {
  69         /* Reduce nodes degree ... */
  70         initial_simplify_edges(pbqp);
  71
  72         /* ... and put node into bucket representing their degree. */
  73         fill_node_buckets(pbqp);
  74
  75 #if KAPS_STATISTIC
  76         FILE *fh = fopen("solutions.pb", "a");
  77         fprintf(fh, "Solution");
  78         fclose(fh);
  79 #endif
  80
  81         apply_heuristic_reductions(pbqp);
  82
  83         pbqp->solution = determine_solution(pbqp);
  84
  85 #if KAPS_STATISTIC
  86         fh = fopen("solutions.pb", "a");
  87         fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RN/BF:%u\n", pbqp->solution,
  88                                 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
  89                                 pbqp->num_rn);
  90         fclose(fh);
  91 #endif
  92
  93         /* Solve reduced nodes. */
  94         back_propagate(pbqp);
  95
  96         free_buckets();
  97 }
  98
  99 void apply_RN(pbqp *pbqp)
 100 {
 101         pbqp_node   *node         = NULL;
 102         unsigned     min_index    = 0;
 103
 104         assert(pbqp);
 105
 106         /* We want to reduce a node with maximum degree. */
 107         node = get_node_with_max_degree();
 108         assert(node);
 109         assert(pbqp_node_get_degree(node) > 2);
 110
 111 #if     KAPS_DUMP
 112         if (pbqp->dump_file) {
 113                 char     txt[100];
 114                 sprintf(txt, "RN-Reduction of Node n%d", node->index);
 115                 dump_section(pbqp->dump_file, 2, txt);
 116                 pbqp_dump_graph(pbqp);
 117         }
 118 #endif
 119
 120         min_index = get_local_minimal_alternative(pbqp, node);
 121
 122 #if     KAPS_DUMP
 123         if (pbqp->dump_file) {
 124                 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
 125                                         node->index, min_index);
 126         }
 127 #endif
 128
 129 #if KAPS_STATISTIC
 130         if (dump == 0) {
 131                 FILE *fh = fopen("solutions.pb", "a");
 132                 fprintf(fh, "[%u]", min_index);
 133                 fclose(fh);
 134                 pbqp->num_rn++;
 135         }
 136 #endif
 137
 138         /* Now that we found the local minimum set all other costs to infinity. */
 139         select_alternative(node, min_index);
 140 }