nsz Git - libfirm/blob - ir/be/beifg_clique.c

   1 /*
   2  * Copyright (C) 1995-2007 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 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <stdlib.h>
  32
  33 #include "belive_t.h"
  34 #include "list.h"
  35
  36 #include "irnode_t.h"
  37 #include "irgraph_t.h"
  38 #include "irgwalk.h"
  39 #include "irbitset.h"
  40
  41 #include "bearch_t.h"
  42 #include "be_t.h"
  43 #include "beintlive_t.h"
  44 #include "beifg_t.h"
  45 #include "bechordal_t.h"
  46 #include "benodesets.h"
  47
  48 typedef struct _cli_head_t {
  49         struct list_head   list;
  50         struct _cli_head_t *next_cli_head;
  51         ir_node            *min;
  52         ir_node            *max;
  53 } cli_head_t;
  54
  55 typedef struct _ifg_clique_t {
  56         const be_ifg_impl_t    *impl;
  57         const be_chordal_env_t *env;
  58         cli_head_t             *cli_root;
  59         struct obstack         obst;
  60         cli_head_t             *curr_cli_head;
  61 } ifg_clique_t;
  62
  63 typedef struct _cli_element_t {
  64         struct list_head list;
  65         ir_node          *irn;
  66 } cli_element_t;
  67
  68 typedef struct _cli_iter_t {
  69         const ifg_clique_t *ifg;
  70         cli_head_t         *curr_cli_head;
  71         cli_element_t      *curr_cli_element;
  72         const ir_node      *curr_irn;
  73         bitset_t           *visited_neighbours;
  74         bitset_t           *visited_nodes;
  75 } cli_iter_t;
  76
  77 /* PRIVATE FUNCTIONS */
  78 static cli_head_t *get_new_cli_head(ifg_clique_t *ifg)
  79 {
  80         cli_head_t *cli_head;
  81         cli_head_t *new_cli_head;
  82
  83         if (ifg->cli_root == NULL)
  84         {
  85                 new_cli_head = obstack_alloc(&ifg->obst, sizeof(*new_cli_head));
  86                 INIT_LIST_HEAD(&new_cli_head->list);
  87                 ifg->cli_root = new_cli_head;
  88         }
  89         else
  90         {
  91                 cli_head = ifg->cli_root;
  92                 while(!(cli_head->next_cli_head == NULL))
  93                 {
  94                         cli_head = cli_head->next_cli_head;
  95                 }
  96                 new_cli_head = obstack_alloc(&ifg->obst, sizeof(*new_cli_head));
  97                 INIT_LIST_HEAD(&new_cli_head->list);
  98                 cli_head->next_cli_head = new_cli_head;
  99         }
 100
 101         new_cli_head->min = NULL;
 102         new_cli_head->max = NULL;
 103         new_cli_head->next_cli_head = NULL;
 104         ifg->curr_cli_head = new_cli_head;
 105
 106         return new_cli_head;
 107 }
 108
 109 static cli_element_t *get_new_cli_element(ifg_clique_t *ifg)
 110 {
 111         cli_element_t *cli_element;
 112
 113         cli_element = obstack_alloc(&ifg->obst, sizeof(*cli_element));
 114         INIT_LIST_HEAD(&cli_element->list);
 115
 116         return cli_element;
 117 }
 118
 119 static void write_clique(nodeset *live_set, ifg_clique_t *ifg)
 120 {
 121         ir_node *live_irn;
 122         ir_node *test_node;
 123         int test_int = 0;
 124         ir_node *max_node = NULL;
 125         ir_node *min_node = NULL;
 126         cli_element_t *new_element = NULL;
 127         cli_element_t *element = NULL;
 128         cli_head_t *cli_head = get_new_cli_head(ifg);
 129         int is_element = 0;
 130
 131         foreach_nodeset(live_set, live_irn)
 132         {
 133                 /* test if node is max or min dominator*/
 134                 test_node = live_irn;
 135                 if (max_node == NULL)
 136                 {
 137                         max_node = test_node;
 138                         min_node = test_node;
 139                 }
 140                 else
 141                 {
 142                         test_int = value_dominates(test_node, max_node);
 143                         if (test_int == 1)
 144                         {
 145                                 max_node = test_node;
 146                         }
 147                         test_int = value_dominates(min_node, test_node);
 148                         if (test_int == 1)
 149                         {
 150                                 min_node = test_node;
 151                         }
 152                 }
 153
 154                 list_for_each_entry(cli_element_t, element, &cli_head->list, list){
 155                         if(element->irn == live_irn){
 156                                 is_element = 1;
 157                                 break;
 158                         }
 159                 }
 160
 161                 if (!is_element){
 162                         new_element = get_new_cli_element(ifg);
 163                         new_element->irn = live_irn;
 164                         list_add(&new_element->list, &cli_head->list) ;
 165                 }
 166         }
 167
 168         cli_head->min = min_node;
 169         cli_head->max = max_node;
 170 }
 171
 172 static cli_head_t *get_next_cli_head(const ir_node *irn, cli_iter_t *it) /* ...containing the node *irn */
 173 {
 174         cli_head_t *head;
 175         cli_element_t *element;
 176
 177         int is_dominated_by_max;
 178         //int dominates_min;
 179
 180         if (it->curr_cli_head == NULL || it->curr_cli_head->next_cli_head == NULL) /* way back of recursion or this is the last clique */
 181         {
 182                 it->curr_cli_head = NULL;
 183                 return NULL;
 184         }
 185
 186         head = it->curr_cli_head->next_cli_head;
 187
 188         is_dominated_by_max = value_dominates(head->max, irn);
 189         //dominates_min = value_dominates(irn, head->min);
 190
 191         if ((is_dominated_by_max) || (irn == head->max)) /* node could be in clique */
 192         {
 193                 /* check if node is in clique */
 194                 list_for_each_entry(cli_element_t, element, &head->list, list)
 195                 {
 196                         if (&element->list != &head->list)
 197                         {
 198                                 if (element->irn == irn)
 199                                 {
 200                                         /* node is in clique */
 201                                         it->curr_cli_head    = head;
 202                                         /* needed because the next element is searched with list.next of it->curr_cli_element */
 203                                         it->curr_cli_element = (void *) head;
 204                                         break;
 205                                 }
 206                         }
 207                 }
 208
 209                 if (it->curr_cli_head != head) /*node was not in clique */
 210                 {
 211                         it->curr_cli_head = head;
 212                         head = get_next_cli_head(irn, it);
 213                 }
 214         }
 215         else
 216         {
 217                 it->curr_cli_head = head;
 218                 head = get_next_cli_head(irn, it);
 219         }
 220         return head;
 221 }
 222
 223 /* ... of the current clique, returns NULL if there were no more elements ..*/
 224 static cli_element_t *get_next_element(const ir_node *irn, cli_iter_t *it)
 225 {
 226         cli_element_t *element = it->curr_cli_element;
 227         cli_head_t    *head    = it->curr_cli_head;
 228
 229         if (!head || it->curr_cli_element == NULL) /* way back of recursion or there are no more heads */
 230         {
 231                 it->curr_cli_element = NULL;
 232                 return NULL;
 233         }
 234         else
 235         {
 236                 element = list_entry(element->list.next, cli_element_t, list);
 237
 238                 if (&element->list == &head->list) /* Clique has no more elements */
 239                 {
 240                         head = get_next_cli_head(irn, it);
 241                         element = get_next_element(irn, it);
 242                 }
 243
 244                 if (element && element->irn == irn) /* the node you are searching neighbors for */
 245                 {
 246                         it->curr_cli_element = element;
 247                         element = get_next_element(irn, it);
 248                 }
 249
 250                 it->curr_cli_element = element;
 251
 252                 return element;
 253         }
 254 }
 255
 256 static void find_nodes(const ifg_clique_t *ifg, cli_iter_t *it)
 257 {
 258         cli_element_t *element;
 259         cli_head_t *cli_head = ifg->cli_root;
 260
 261         bitset_t *bitset_visnodes = bitset_malloc(get_irg_last_idx(ifg->env->irg));
 262
 263         it->visited_nodes = bitset_visnodes;
 264         it->curr_cli_head = cli_head;
 265
 266         assert(cli_head && "There is no root entry to work on!");
 267
 268         if (cli_head->list.next != &cli_head->list) /* if cli_head contains an element */
 269         {
 270                 element = list_entry(cli_head->list.next, cli_element_t, list);
 271                 it->curr_cli_element = element;
 272         }
 273
 274         return;
 275 }
 276
 277 static ir_node *get_next_node(cli_iter_t *it)
 278 {
 279         cli_head_t *cli_head = NULL;
 280         cli_element_t *element = it->curr_cli_element;
 281
 282         ir_node *irn;
 283
 284         if (element == NULL)
 285                 return NULL;
 286
 287         if (!(&it->curr_cli_head->list == element->list.next))
 288         {
 289                 irn = element->irn;
 290                 element = list_entry(element->list.next, cli_element_t, list);
 291                 it->curr_cli_element = element;
 292         }
 293         else /* reached end of clique */
 294         {
 295                 cli_head = it->curr_cli_head;
 296                 if (!(cli_head->next_cli_head == NULL))
 297                 {
 298                         irn = element->irn;
 299                         cli_head = cli_head->next_cli_head;
 300                         it->curr_cli_head = cli_head;
 301                         element = list_entry(cli_head->list.next, cli_element_t, list);
 302                         it->curr_cli_element = element;
 303                 }
 304                 else
 305                 {
 306                         it->curr_cli_head = NULL;
 307                         it->curr_cli_element = NULL;
 308                         irn = element->irn;
 309                 }
 310         }
 311         if (!(irn == NULL))
 312         {
 313                 if (bitset_is_set(it->visited_nodes, get_irn_idx(irn)))
 314                 {
 315                         irn = get_next_node(it);
 316                 }
 317                 if (!(irn == NULL))
 318                 {
 319                         bitset_set(it->visited_nodes, get_irn_idx(irn));
 320                 }
 321         }
 322
 323         return irn;
 324 }
 325
 326 static void find_neighbour_walker(ir_node *bl, void *data)
 327 {
 328         ifg_clique_t     *ifg    = data;
 329         struct list_head *head   = get_block_border_head(ifg->env, bl);
 330         int              was_def = 0;
 331         nodeset          *live   = new_nodeset(ifg->env->cls->n_regs);
 332         border_t         *b;
 333
 334         assert(is_Block(bl) && "There is no block to work on.");
 335
 336         foreach_border_head(head, b) /* follow the borders of the block */
 337         {
 338                 ir_node *irn = b->irn;
 339
 340                 if (b->is_def) /* b is a new node */
 341                 {
 342                         nodeset_insert(live, irn);
 343                         if(b->is_real)
 344                         {
 345                                 was_def = 1;
 346                         }
 347                 }
 348                 else
 349                 {
 350                         if (was_def == 1) /* if there is a USE after a DEF... */
 351                         {
 352                                 write_clique(live, ifg); /* ...add the clique. */
 353                                 was_def = 0;
 354                         }
 355                         nodeset_remove(live, irn);
 356                 }
 357         }
 358         del_nodeset(live);
 359 }
 360
 361 static void find_first_neighbour(const ifg_clique_t *ifg, cli_iter_t *it, const ir_node *irn)
 362 {
 363         cli_head_t    *cli_head = ifg->cli_root;
 364         cli_element_t *element;
 365         bitset_t      *bitset_visneighbours = bitset_malloc(get_irg_last_idx(ifg->env->irg));
 366
 367         int is_dominated_by_max = 0;
 368         int dominates_min = 0;
 369         int is_in_clique = 0;
 370
 371         it->curr_cli_head = cli_head;
 372         it->ifg = ifg;
 373         it->visited_neighbours = bitset_visneighbours;
 374
 375         assert(cli_head && "There is no root entry for a cli_head.");
 376
 377         is_dominated_by_max = value_dominates(cli_head->max, irn);
 378         dominates_min = value_dominates(irn, cli_head->min);
 379
 380         if ((is_dominated_by_max) || (irn == cli_head->max))  /* node could be in clique */
 381         {
 382                 /* check if node is in clique */
 383                 list_for_each_entry(cli_element_t, element, &cli_head->list, list)
 384                 {
 385                         if (element->irn == irn) /* node is in clique */
 386                         {
 387                                 it->curr_cli_element = (void *) cli_head; /* needed because the next element is searched with list.next of it->curr_cli_element */
 388                                 is_in_clique = 1;
 389                                 element = get_next_element(irn, it);
 390                                 break;
 391                         }
 392                 }
 393         }
 394         if(!is_in_clique)
 395         {
 396                 cli_head = get_next_cli_head(irn, it);
 397                 element = get_next_element(irn, it);
 398         }
 399
 400         it->curr_cli_element = element;
 401         it->curr_irn = irn;
 402
 403         return;
 404 }
 405
 406 static ir_node *get_next_neighbour(cli_iter_t *it)
 407 {
 408         ir_node *res = NULL;
 409         const ir_node *irn = it->curr_irn;
 410
 411         if (it->curr_cli_element != NULL)
 412                 res = it->curr_cli_element->irn;
 413         else
 414                 return NULL;
 415
 416         it->curr_cli_element = get_next_element(irn, it);
 417
 418         if (res)
 419         {
 420                 if (bitset_contains_irn(it->visited_neighbours, res))
 421                 {
 422                         res = get_next_neighbour(it);
 423                 }
 424                 else
 425                 {
 426                         bitset_set(it->visited_neighbours, get_irn_idx(res));
 427                 }
 428         }
 429
 430         return res;
 431 }
 432
 433
 434 /* PUBLIC FUNCTIONS */
 435
 436 static void ifg_clique_free(void *self)
 437 {
 438         ifg_clique_t *ifg = self;
 439         obstack_free(&ifg->obst, NULL);
 440
 441         free(self);
 442 }
 443
 444 static int ifg_clique_connected(const void *self, const ir_node *a, const ir_node *b)
 445 {
 446         const ifg_clique_t *ifg = self;
 447         cli_iter_t it;
 448         int connected = -1;
 449         ir_node *irn = NULL;
 450
 451         find_first_neighbour(ifg, &it, a);
 452         connected = 0;
 453         irn = get_next_neighbour(&it);
 454         while (irn != NULL)
 455         {
 456                 if (irn == b)
 457                 {
 458                         connected = 1;
 459                         break;
 460                 }
 461                 irn = get_next_neighbour(&it);
 462         }
 463
 464         return connected;
 465 }
 466
 467 static ir_node *ifg_clique_neighbours_begin(const void *self, void *iter, const ir_node *irn)
 468 {
 469         find_first_neighbour(self, iter, irn);
 470         return get_next_neighbour(iter);
 471 }
 472
 473 static ir_node *ifg_clique_neighbours_next(const void *self, void *iter)
 474 {
 475         (void) self;
 476         return get_next_neighbour(iter);
 477 }
 478
 479 static void ifg_clique_neighbours_break(const void *self, void *iter)
 480 {
 481         cli_iter_t *it = iter;
 482         (void) self;
 483
 484         bitset_free(it->visited_neighbours);
 485
 486         return;
 487 }
 488
 489 static ir_node *ifg_clique_nodes_begin(const void *self, void *iter)
 490 {
 491         find_nodes(self, iter);
 492         return get_next_node(iter);
 493 }
 494
 495 static ir_node *ifg_clique_nodes_next(const void *self, void *iter)
 496 {
 497         (void) self;
 498         return get_next_node(iter);
 499 }
 500
 501 static void ifg_clique_nodes_break(const void *self, void *iter)
 502 {
 503         cli_iter_t *it = iter;
 504         (void) self;
 505
 506         bitset_free(it->visited_nodes);
 507
 508         return;
 509 }
 510
 511 static int ifg_clique_degree(const void *self, const ir_node *irn)
 512 {
 513         int degree = -1;
 514         cli_iter_t it;
 515
 516         find_first_neighbour(self, &it, irn);
 517         degree = 0;
 518         irn = get_next_neighbour(&it);
 519         while (irn != NULL)
 520         {
 521                 degree++;
 522                 irn = get_next_neighbour(&it);
 523         }
 524
 525         return degree;
 526 }
 527
 528 static const be_ifg_impl_t ifg_clique_impl = {
 529         sizeof(cli_iter_t),
 530         sizeof(cli_iter_t),
 531         0,
 532         ifg_clique_free,
 533         ifg_clique_connected,
 534         ifg_clique_neighbours_begin,
 535         ifg_clique_neighbours_next,
 536         ifg_clique_neighbours_break,
 537         ifg_clique_nodes_begin,
 538         ifg_clique_nodes_next,
 539         ifg_clique_nodes_break,
 540         NULL,
 541         NULL,
 542         NULL,
 543         ifg_clique_degree
 544 };
 545
 546 be_ifg_t *be_ifg_clique_new(const be_chordal_env_t *env)
 547 {
 548         ifg_clique_t *ifg       = xmalloc(sizeof(*ifg));
 549
 550         ifg->impl               = &ifg_clique_impl;
 551         ifg->env                        = env;
 552
 553         ifg->cli_root           = NULL;
 554         obstack_init(&ifg->obst);
 555
 556         dom_tree_walk_irg(env->irg, find_neighbour_walker, NULL, ifg);
 557
 558         obstack_finish(&ifg->obst);
 559         return (be_ifg_t *) ifg;
 560 }