nsz Git - libfirm/blob - heuristical_co.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 for SSA-based register allocation.
  23  * @date    18.09.2009
  24  * @author  Thomas Bersch
  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_co.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_RN_co(pbqp *pbqp, plist_t *rpeo)
  51 {
  52         pbqp_node   *node         = NULL;
  53         unsigned     min_index    = 0;
  54
  55         assert(pbqp);
  56
  57         /* We want to reduce the first node in reverse perfect elimination order. */
  58         do {
  59                 /* get first element from reverse perfect elimination order */
  60                 node = plist_first(rpeo)->data;
  61                 /* remove element from reverse perfect elimination order */
  62                 plist_erase(rpeo, plist_first(rpeo));
  63                 /* insert node at the end of rpeo so the rpeo already exits after pbqp solving */
  64                 plist_insert_back(rpeo, node);
  65         } while(node_is_reduced(node));
  66
  67         assert(node);
  68         assert(pbqp_node_get_degree(node) > 2);
  69
  70 #if     KAPS_DUMP
  71         if (pbqp->dump_file) {
  72                 char     txt[100];
  73                 sprintf(txt, "RN-Reduction of Node n%d", node->index);
  74                 dump_section(pbqp->dump_file, 2, txt);
  75                 pbqp_dump_graph(pbqp);
  76         }
  77 #endif
  78 #if KAPS_STATISTIC
  79         /* Check whether we can merge a neighbor into the current node. */
  80         for (min_index = 0; min_index < pbqp_node_get_degree(node); ++min_index) {
  81                 check_melting_possibility(pbqp, node->edges[min_index]);
  82         }
  83 #endif
  84
  85         min_index = get_local_minimal_alternative(pbqp, node);
  86
  87 #if     KAPS_DUMP
  88         if (pbqp->dump_file) {
  89                 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
  90                                         node->index, min_index);
  91         }
  92 #endif
  93
  94 #if KAPS_STATISTIC
  95                 FILE *fh = fopen("solutions.pb", "a");
  96                 fprintf(fh, "[%u]", min_index);
  97                 fclose(fh);
  98                 pbqp->num_rn++;
  99 #endif
 100
 101         /* Now that we found the local minimum set all other costs to infinity. */
 102         select_alternative(node, min_index);
 103 }
 104
 105 static void apply_heuristic_reductions_co(pbqp *pbqp, plist_t *rpeo)
 106 {
 107         #if KAPS_TIMING
 108                 /* create timers */
 109                 ir_timer_t *t_edge = ir_timer_new();
 110                 ir_timer_t *t_r0   = ir_timer_new();
 111                 ir_timer_t *t_r1   = ir_timer_new();
 112                 ir_timer_t *t_r2   = ir_timer_new();
 113                 ir_timer_t *t_rn   = ir_timer_new();
 114         #endif
 115
 116         for (;;) {
 117                 if (edge_bucket_get_length(edge_bucket) > 0) {
 118                         #if KAPS_TIMING
 119                                 ir_timer_start(t_r0);
 120                         #endif
 121
 122                         apply_edge(pbqp);
 123
 124                         #if KAPS_TIMING
 125                                 ir_timer_stop(t_r0);
 126                         #endif
 127                 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
 128                         #if KAPS_TIMING
 129                                 ir_timer_start(t_r1);
 130                         #endif
 131
 132                         apply_RI(pbqp);
 133
 134                         #if KAPS_TIMING
 135                                 ir_timer_stop(t_r1);
 136                         #endif
 137                 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
 138                         #if KAPS_TIMING
 139                                 ir_timer_start(t_r2);
 140                         #endif
 141
 142                         apply_RII(pbqp);
 143
 144                         #if KAPS_TIMING
 145                                 ir_timer_stop(t_r2);
 146                         #endif
 147                 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
 148                         #if KAPS_TIMING
 149                                 ir_timer_start(t_rn);
 150                         #endif
 151
 152                         apply_RN_co(pbqp, rpeo);
 153
 154                         #if KAPS_TIMING
 155                                 ir_timer_stop(t_rn);
 156                         #endif
 157                 } else {
 158                         #if KAPS_TIMING
 159                                 printf("pbqp reduce independent edges: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_edge) / 1000.0);
 160                                 printf("pbqp R0 reductions: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_r0) / 1000.0);
 161                                 printf("pbqp R1 reductions: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_r1) / 1000.0);
 162                                 printf("pbqp R2 reductions: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_r2) / 1000.0);
 163                                 printf("pbqp RN reductions: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_rn) / 1000.0);
 164                         #endif
 165
 166                         return;
 167                 }
 168         }
 169 }
 170
 171 void solve_pbqp_heuristical_co(pbqp *pbqp, plist_t *rpeo)
 172 {
 173         /* Reduce nodes degree ... */
 174         initial_simplify_edges(pbqp);
 175
 176         /* ... and put node into bucket representing their degree. */
 177         fill_node_buckets(pbqp);
 178
 179         #if KAPS_STATISTIC
 180                 FILE *fh = fopen("solutions.pb", "a");
 181                 fprintf(fh, "Solution");
 182                 fclose(fh);
 183         #endif
 184
 185         apply_heuristic_reductions_co(pbqp, rpeo);
 186
 187         pbqp->solution = determine_solution(pbqp);
 188
 189         #if KAPS_STATISTIC
 190                 fh = fopen("solutions.pb", "a");
 191                 fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RN/BF:%u\n", pbqp->solution,
 192                                         pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
 193                                         pbqp->num_rn);
 194                 fclose(fh);
 195         #endif
 196
 197         /* Solve reduced nodes. */
 198         back_propagate(pbqp);
 199
 200         free_buckets();
 201 }