nsz Git - libfirm/blob - ir/be/beifg_clique.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       Clique calculation for chordal ifg.
  23  * @author      Sebastian Hack
  24  * @date        18.11.2005
  25  * @version     $Id$
  26  */
  27 #include "config.h"
  28
  29 #include <stdlib.h>
  30
  31 #include "belive_t.h"
  32 #include "list.h"
  33
  34 #include "irnode_t.h"
  35 #include "irgraph_t.h"
  36 #include "irgwalk.h"
  37 #include "irbitset.h"
  38
  39 #include "bearch.h"
  40 #include "be_t.h"
  41 #include "beintlive_t.h"
  42 #include "beifg_t.h"
  43 #include "beifg_impl.h"
  44 #include "bechordal_t.h"
  45
  46 typedef struct _cli_head_t {
  47         struct list_head   list;
  48         struct _cli_head_t *next_cli_head;
  49         ir_node            *min;
  50         ir_node            *max;
  51 } cli_head_t;
  52
  53 typedef struct _ifg_clique_t {
  54         const be_ifg_impl_t    *impl;
  55         const be_chordal_env_t *env;
  56         cli_head_t             *cli_root;
  57         struct obstack         obst;
  58         cli_head_t             *curr_cli_head;
  59 } ifg_clique_t;
  60
  61 typedef struct _cli_element_t {
  62         struct list_head list;
  63         ir_node          *irn;
  64 } cli_element_t;
  65
  66 typedef struct _cli_iter_t {
  67         const ifg_clique_t *ifg;
  68         cli_head_t         *curr_cli_head;
  69         cli_element_t      *curr_cli_element;
  70         const ir_node      *curr_irn;
  71         bitset_t           *visited_neighbours;
  72         bitset_t           *visited_nodes;
  73 } cli_iter_t;
  74
  75 /* PRIVATE FUNCTIONS */
  76 static cli_head_t *get_new_cli_head(ifg_clique_t *ifg)
  77 {
  78         cli_head_t *cli_head;
  79         cli_head_t *new_cli_head;
  80
  81         if (ifg->cli_root == NULL)
  82         {
  83                 new_cli_head = OALLOC(&ifg->obst, cli_head_t);
  84                 INIT_LIST_HEAD(&new_cli_head->list);
  85                 ifg->cli_root = new_cli_head;
  86         }
  87         else
  88         {
  89                 cli_head = ifg->cli_root;
  90                 while (!(cli_head->next_cli_head == NULL))
  91                 {
  92                         cli_head = cli_head->next_cli_head;
  93                 }
  94                 new_cli_head = OALLOC(&ifg->obst, cli_head_t);
  95                 INIT_LIST_HEAD(&new_cli_head->list);
  96                 cli_head->next_cli_head = new_cli_head;
  97         }
  98
  99         new_cli_head->min = NULL;
 100         new_cli_head->max = NULL;
 101         new_cli_head->next_cli_head = NULL;
 102         ifg->curr_cli_head = new_cli_head;
 103
 104         return new_cli_head;
 105 }
 106
 107 static cli_element_t *get_new_cli_element(ifg_clique_t *ifg)
 108 {
 109         cli_element_t *cli_element;
 110
 111         cli_element = OALLOC(&ifg->obst, cli_element_t);
 112         INIT_LIST_HEAD(&cli_element->list);
 113
 114         return cli_element;
 115 }
 116
 117 static void write_clique(ir_nodeset_t *live_set, ifg_clique_t *ifg)
 118 {
 119         ir_node *live_irn;
 120         ir_node *test_node;
 121         int test_int = 0;
 122         ir_node *max_node = NULL;
 123         ir_node *min_node = NULL;
 124         cli_element_t *new_element = NULL;
 125         cli_element_t *element = NULL;
 126         cli_head_t *cli_head = get_new_cli_head(ifg);
 127         int is_element = 0;
 128         ir_nodeset_iterator_t iter;
 129
 130         foreach_ir_nodeset(live_set, live_irn, iter)
 131         {
 132                 /* test if node is max or min dominator*/
 133                 test_node = live_irn;
 134                 if (max_node == NULL)
 135                 {
 136                         max_node = test_node;
 137                         min_node = test_node;
 138                 }
 139                 else
 140                 {
 141                         test_int = value_dominates(test_node, max_node);
 142                         if (test_int == 1)
 143                         {
 144                                 max_node = test_node;
 145                         }
 146                         test_int = value_dominates(min_node, test_node);
 147                         if (test_int == 1)
 148                         {
 149                                 min_node = test_node;
 150                         }
 151                 }
 152
 153                 list_for_each_entry(cli_element_t, element, &cli_head->list, list){
 154                         if (element->irn == live_irn){
 155                                 is_element = 1;
 156                                 break;
 157                         }
 158                 }
 159
 160                 if (!is_element){
 161                         new_element = get_new_cli_element(ifg);
 162                         new_element->irn = live_irn;
 163                         list_add(&new_element->list, &cli_head->list) ;
 164                 }
 165         }
 166
 167         cli_head->min = min_node;
 168         cli_head->max = max_node;
 169 }
 170
 171 static cli_head_t *get_next_cli_head(const ir_node *irn, cli_iter_t *it) /* ...containing the node *irn */
 172 {
 173         cli_head_t *head;
 174         cli_element_t *element;
 175
 176         int is_dominated_by_max;
 177         //int dominates_min;
 178
 179         if (it->curr_cli_head == NULL || it->curr_cli_head->next_cli_head == NULL) /* way back of recursion or this is the last clique */
 180         {
 181                 it->curr_cli_head = NULL;
 182                 return NULL;
 183         }
 184
 185         head = it->curr_cli_head->next_cli_head;
 186
 187         is_dominated_by_max = value_dominates(head->max, irn);
 188         //dominates_min = value_dominates(irn, head->min);
 189
 190         if ((is_dominated_by_max) || (irn == head->max)) /* node could be in clique */
 191         {
 192                 /* check if node is in clique */
 193                 list_for_each_entry(cli_element_t, element, &head->list, list)
 194                 {
 195                         if (&element->list != &head->list)
 196                         {
 197                                 if (element->irn == irn)
 198                                 {
 199                                         /* node is in clique */
 200                                         it->curr_cli_head    = head;
 201                                         /* needed because the next element is searched with list.next of it->curr_cli_element */
 202                                         it->curr_cli_element = (void *) head;
 203                                         break;
 204                                 }
 205                         }
 206                 }
 207
 208                 if (it->curr_cli_head != head) /*node was not in clique */
 209                 {
 210                         it->curr_cli_head = head;
 211                         head = get_next_cli_head(irn, it);
 212                 }
 213         }
 214         else
 215         {
 216                 it->curr_cli_head = head;
 217                 head = get_next_cli_head(irn, it);
 218         }
 219         return head;
 220 }
 221
 222 /* ... of the current clique, returns NULL if there were no more elements ..*/
 223 static cli_element_t *get_next_element(const ir_node *irn, cli_iter_t *it)
 224 {
 225         cli_element_t *element = it->curr_cli_element;
 226         cli_head_t    *head    = it->curr_cli_head;
 227
 228         if (!head || it->curr_cli_element == NULL) /* way back of recursion or there are no more heads */
 229         {
 230                 it->curr_cli_element = NULL;
 231                 return NULL;
 232         }
 233         else
 234         {
 235                 element = list_entry(element->list.next, cli_element_t, list);
 236
 237                 if (&element->list == &head->list) /* Clique has no more elements */
 238                 {
 239                         head = get_next_cli_head(irn, it);
 240                         element = get_next_element(irn, it);
 241                 }
 242
 243                 if (element && element->irn == irn) /* the node you are searching neighbors for */
 244                 {
 245                         it->curr_cli_element = element;
 246                         element = get_next_element(irn, it);
 247                 }
 248
 249                 it->curr_cli_element = element;
 250
 251                 return element;
 252         }
 253 }
 254
 255 static void find_nodes(const ifg_clique_t *ifg, cli_iter_t *it)
 256 {
 257         cli_element_t *element;
 258         cli_head_t *cli_head = ifg->cli_root;
 259
 260         bitset_t *bitset_visnodes = bitset_malloc(get_irg_last_idx(ifg->env->irg));
 261
 262         it->visited_nodes = bitset_visnodes;
 263         it->curr_cli_head = cli_head;
 264
 265         assert(cli_head && "There is no root entry to work on!");
 266
 267         if (cli_head->list.next != &cli_head->list) /* if cli_head contains an element */
 268         {
 269                 element = list_entry(cli_head->list.next, cli_element_t, list);
 270                 it->curr_cli_element = element;
 271         }
 272 }
 273
 274 static ir_node *get_next_node(cli_iter_t *it)
 275 {
 276         cli_head_t *cli_head = NULL;
 277         cli_element_t *element = it->curr_cli_element;
 278
 279         ir_node *irn;
 280
 281         if (element == NULL)
 282                 return NULL;
 283
 284         if (!(&it->curr_cli_head->list == element->list.next))
 285         {
 286                 irn = element->irn;
 287                 element = list_entry(element->list.next, cli_element_t, list);
 288                 it->curr_cli_element = element;
 289         }
 290         else /* reached end of clique */
 291         {
 292                 cli_head = it->curr_cli_head;
 293                 if (!(cli_head->next_cli_head == NULL))
 294                 {
 295                         irn = element->irn;
 296                         cli_head = cli_head->next_cli_head;
 297                         it->curr_cli_head = cli_head;
 298                         element = list_entry(cli_head->list.next, cli_element_t, list);
 299                         it->curr_cli_element = element;
 300                 }
 301                 else
 302                 {
 303                         it->curr_cli_head = NULL;
 304                         it->curr_cli_element = NULL;
 305                         irn = element->irn;
 306                 }
 307         }
 308         if (!(irn == NULL))
 309         {
 310                 if (bitset_is_set(it->visited_nodes, get_irn_idx(irn)))
 311                 {
 312                         irn = get_next_node(it);
 313                 }
 314                 if (!(irn == NULL))
 315                 {
 316                         bitset_set(it->visited_nodes, get_irn_idx(irn));
 317                 }
 318         }
 319
 320         return irn;
 321 }
 322
 323 static void find_neighbour_walker(ir_node *bl, void *data)
 324 {
 325         ifg_clique_t     *ifg    = data;
 326         struct list_head *head   = get_block_border_head(ifg->env, bl);
 327         int               was_def = 0;
 328         ir_nodeset_t      live;
 329         border_t         *b;
 330
 331         ir_nodeset_init(&live);
 332
 333         assert(is_Block(bl) && "There is no block to work on.");
 334
 335         foreach_border_head(head, b) /* follow the borders of the block */
 336         {
 337                 ir_node *irn = b->irn;
 338
 339                 if (b->is_def) /* b is a new node */
 340                 {
 341                         ir_nodeset_insert(&live, irn);
 342                         if (b->is_real)
 343                         {
 344                                 was_def = 1;
 345                         }
 346                 }
 347                 else
 348                 {
 349                         if (was_def == 1) /* if there is a USE after a DEF... */
 350                         {
 351                                 write_clique(&live, ifg); /* ...add the clique. */
 352                                 was_def = 0;
 353                         }
 354                         ir_nodeset_remove(&live, irn);
 355                 }
 356         }
 357         ir_nodeset_destroy(&live);
 358 }
 359
 360 static void find_first_neighbour(const ifg_clique_t *ifg, cli_iter_t *it, const ir_node *irn)
 361 {
 362         cli_head_t    *cli_head = ifg->cli_root;
 363         cli_element_t *element;
 364         bitset_t      *bitset_visneighbours = bitset_malloc(get_irg_last_idx(ifg->env->irg));
 365
 366         int is_dominated_by_max = 0;
 367         int dominates_min = 0;
 368         int is_in_clique = 0;
 369
 370         it->curr_cli_head = cli_head;
 371         it->ifg = ifg;
 372         it->visited_neighbours = bitset_visneighbours;
 373
 374         assert(cli_head && "There is no root entry for a cli_head.");
 375
 376         is_dominated_by_max = value_dominates(cli_head->max, irn);
 377         dominates_min = value_dominates(irn, cli_head->min);
 378
 379         if ((is_dominated_by_max) || (irn == cli_head->max))  /* node could be in clique */
 380         {
 381                 /* check if node is in clique */
 382                 list_for_each_entry(cli_element_t, element, &cli_head->list, list)
 383                 {
 384                         if (element->irn == irn) /* node is in clique */
 385                         {
 386                                 it->curr_cli_element = (void *) cli_head; /* needed because the next element is searched with list.next of it->curr_cli_element */
 387                                 is_in_clique = 1;
 388                                 element = get_next_element(irn, it);
 389                                 break;
 390                         }
 391                 }
 392         }
 393         if (!is_in_clique)
 394         {
 395                 cli_head = get_next_cli_head(irn, it);
 396                 element = get_next_element(irn, it);
 397         }
 398
 399         it->curr_cli_element = element;
 400         it->curr_irn = irn;
 401 }
 402
 403 static ir_node *get_next_neighbour(cli_iter_t *it)
 404 {
 405         ir_node *res = NULL;
 406         const ir_node *irn = it->curr_irn;
 407
 408         if (it->curr_cli_element != NULL)
 409                 res = it->curr_cli_element->irn;
 410         else
 411                 return NULL;
 412
 413         it->curr_cli_element = get_next_element(irn, it);
 414
 415         if (res)
 416         {
 417                 if (bitset_contains_irn(it->visited_neighbours, res))
 418                 {
 419                         res = get_next_neighbour(it);
 420                 }
 421                 else
 422                 {
 423                         bitset_set(it->visited_neighbours, get_irn_idx(res));
 424                 }
 425         }
 426
 427         return res;
 428 }
 429
 430
 431 /* PUBLIC FUNCTIONS */
 432
 433 static void ifg_clique_free(void *self)
 434 {
 435         ifg_clique_t *ifg = self;
 436         obstack_free(&ifg->obst, NULL);
 437
 438         free(self);
 439 }
 440
 441 static int ifg_clique_connected(const void *self, const ir_node *a, const ir_node *b)
 442 {
 443         const ifg_clique_t *ifg = self;
 444         cli_iter_t it;
 445         int connected = -1;
 446         ir_node *irn = NULL;
 447
 448         find_first_neighbour(ifg, &it, a);
 449         connected = 0;
 450         irn = get_next_neighbour(&it);
 451         while (irn != NULL)
 452         {
 453                 if (irn == b)
 454                 {
 455                         connected = 1;
 456                         break;
 457                 }
 458                 irn = get_next_neighbour(&it);
 459         }
 460
 461         return connected;
 462 }
 463
 464 static ir_node *ifg_clique_neighbours_begin(const void *self, void *iter, const ir_node *irn)
 465 {
 466         find_first_neighbour(self, iter, irn);
 467         return get_next_neighbour(iter);
 468 }
 469
 470 static ir_node *ifg_clique_neighbours_next(const void *self, void *iter)
 471 {
 472         (void) self;
 473         return get_next_neighbour(iter);
 474 }
 475
 476 static void ifg_clique_neighbours_break(const void *self, void *iter)
 477 {
 478         cli_iter_t *it = iter;
 479         (void) self;
 480
 481         bitset_free(it->visited_neighbours);
 482 }
 483
 484 static ir_node *ifg_clique_nodes_begin(const void *self, void *iter)
 485 {
 486         find_nodes(self, iter);
 487         return get_next_node(iter);
 488 }
 489
 490 static ir_node *ifg_clique_nodes_next(const void *self, void *iter)
 491 {
 492         (void) self;
 493         return get_next_node(iter);
 494 }
 495
 496 static void ifg_clique_nodes_break(const void *self, void *iter)
 497 {
 498         cli_iter_t *it = iter;
 499         (void) self;
 500
 501         bitset_free(it->visited_nodes);
 502 }
 503
 504 static int ifg_clique_degree(const void *self, const ir_node *irn)
 505 {
 506         int degree = -1;
 507         cli_iter_t it;
 508
 509         find_first_neighbour(self, &it, irn);
 510         degree = 0;
 511         irn = get_next_neighbour(&it);
 512         while (irn != NULL)
 513         {
 514                 degree++;
 515                 irn = get_next_neighbour(&it);
 516         }
 517
 518         return degree;
 519 }
 520
 521 static const be_ifg_impl_t ifg_clique_impl = {
 522         sizeof(cli_iter_t),
 523         sizeof(cli_iter_t),
 524         0,
 525         ifg_clique_free,
 526         ifg_clique_connected,
 527         ifg_clique_neighbours_begin,
 528         ifg_clique_neighbours_next,
 529         ifg_clique_neighbours_break,
 530         ifg_clique_nodes_begin,
 531         ifg_clique_nodes_next,
 532         ifg_clique_nodes_break,
 533         NULL,
 534         NULL,
 535         NULL,
 536         ifg_clique_degree
 537 };
 538
 539 be_ifg_t *be_ifg_clique_new(const be_chordal_env_t *env)
 540 {
 541         ifg_clique_t *ifg       = XMALLOC(ifg_clique_t);
 542
 543         ifg->impl               = &ifg_clique_impl;
 544         ifg->env                        = env;
 545
 546         ifg->cli_root           = NULL;
 547         obstack_init(&ifg->obst);
 548
 549         dom_tree_walk_irg(env->irg, find_neighbour_walker, NULL, ifg);
 550
 551         obstack_finish(&ifg->obst);
 552         return (be_ifg_t *) ifg;
 553 }