nsz Git - libfirm/blob - ir/ir/irgwalk.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   Functions for traversing ir graphs
  23  * @author  Boris Boesler, Goetz Lindenmaier, Michael Beck
  24  * @version $Id$
  25  * @brief
  26  *  traverse an ir graph
  27  *  - execute the pre function before recursion
  28  *  - execute the post function after recursion
  29  */
  30 #include "config.h"
  31
  32 #include <stdlib.h>
  33
  34 #include "irnode_t.h"
  35 #include "irgraph_t.h"
  36 #include "irprog.h"
  37 #include "irgwalk.h"
  38 #include "irhooks.h"
  39 #include "ircgcons.h"
  40 #include "entity_t.h"
  41
  42 #include "error.h"
  43 #include "pset_new.h"
  44 #include "array.h"
  45
  46 #ifdef INTERPROCEDURAL_VIEW
  47 /**
  48  * Walk over an interprocedural graph (callgraph).
  49  * Visits only graphs in irg_set.
  50  */
  51 static void irg_walk_cg(ir_node * node, ir_visited_t visited,
  52                         pset_new_t *irg_set, irg_walk_func *pre,
  53                         irg_walk_func *post, void * env)
  54 {
  55         int i;
  56         ir_graph * rem = current_ir_graph;
  57         ir_node * pred;
  58
  59         assert(node && node->kind == k_ir_node);
  60         if (get_irn_visited(node) >= visited) return;
  61
  62         set_irn_visited(node, visited);
  63
  64         if (pre) pre(node, env);
  65
  66         pred = skip_Proj(node);
  67         if (is_CallBegin(pred)            ||
  68             get_irn_op(pred) == op_EndReg ||
  69             get_irn_op(pred) == op_EndExcept) {
  70                 current_ir_graph = get_irn_irg(pred);
  71         }
  72
  73         if (is_no_Block(node)) { /* not block */
  74                 irg_walk_cg(get_nodes_block(node), visited, irg_set, pre, post, env);
  75         }
  76
  77         if (is_Block(node)) { /* block */
  78                 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
  79                         ir_node * exec = get_irn_n(node, i);
  80                         ir_node * pred = skip_Proj(exec);
  81                         if ((
  82                               !is_CallBegin(pred)           &&
  83                               get_irn_op(pred) != op_EndReg &&
  84                               get_irn_op(pred) != op_EndExcept
  85                             ) || pset_new_contains(irg_set, get_irn_irg(pred))) {
  86                                 irg_walk_cg(exec, visited, irg_set, pre, post, env);
  87                         }
  88                 }
  89         } else if (is_Filter(node)) { /* filter */
  90                 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
  91                         ir_node * pred = get_irn_n(node, i);
  92                         if (is_Unknown(pred) || is_Bad(pred)) {
  93                                 irg_walk_cg(pred, visited, irg_set, pre, post, env);
  94                         } else {
  95                                 ir_node * exec;
  96                                 exec = skip_Proj(get_Block_cfgpred(get_nodes_block(node), i));
  97
  98                                 if (is_Bad(exec)) {
  99                                         continue;
 100                                 }
 101
 102                                 assert(is_CallBegin(exec)            ||
 103                                        get_irn_op(exec) == op_EndReg ||
 104                                        get_irn_op(exec) == op_EndExcept);
 105                                 if (pset_new_contains(irg_set, get_irn_irg(exec))) {
 106                                         current_ir_graph = get_irn_irg(exec);
 107                                         irg_walk_cg(pred, visited, irg_set, pre, post, env);
 108                                         current_ir_graph = rem;
 109                                 }
 110                         }
 111                 }
 112         } else {                      /* everything else */
 113                 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 114                         irg_walk_cg(get_irn_n(node, i), visited, irg_set, pre, post, env);
 115                 }
 116         }
 117
 118         if (post) post(node, env);
 119
 120         current_ir_graph = rem;
 121 }
 122
 123 /**
 124  * Insert all ir_graphs in irg_set, that are (transitive) reachable.
 125  */
 126 static void collect_irgs(ir_node * node, pset_new_t *irg_set)
 127 {
 128         if (is_Call(node)) {
 129                 int i;
 130                 for (i = get_Call_n_callees(node) - 1; i >= 0; --i) {
 131                         ir_entity * ent = get_Call_callee(node, i);
 132                         ir_graph * irg = get_entity_irg(ent);
 133                         if (irg && !pset_new_contains(irg_set, irg)) {
 134                                 pset_new_insert(irg_set, irg);
 135                                 irg_walk_graph(irg, (irg_walk_func *) collect_irgs, NULL, irg_set);
 136                         }
 137                 }
 138         }
 139 }
 140 #endif
 141
 142 /**
 143  * specialized version of irg_walk_2, called if only pre callback exists
 144  *
 145  * @return number of visited nodes
 146  */
 147 static unsigned irg_walk_2_pre(ir_node *node, irg_walk_func *pre, void * env)
 148 {
 149         int i;
 150         unsigned cnt = 1;
 151         ir_graph *irg = current_ir_graph;
 152
 153         set_irn_visited(node, irg->visited);
 154
 155         pre(node, env);
 156
 157         if (node->op != op_Block) {
 158                 ir_node *pred = get_irn_n(node, -1);
 159                 if (pred->visited < irg->visited)
 160                         cnt += irg_walk_2_pre(pred, pre, env);
 161         }
 162         for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 163                 ir_node *pred = get_irn_n(node, i);
 164                 if (pred->visited < irg->visited)
 165                         cnt += irg_walk_2_pre(pred, pre, env);
 166         }
 167         return cnt;
 168 }
 169
 170 /**
 171  * specialized version of irg_walk_2, called if only post callback exists
 172  *
 173  * @return number of visited nodes
 174  */
 175 static unsigned irg_walk_2_post(ir_node *node, irg_walk_func *post, void * env)
 176 {
 177         int i;
 178         unsigned cnt = 1;
 179         ir_graph *irg = current_ir_graph;
 180
 181         set_irn_visited(node, irg->visited);
 182
 183         if (node->op != op_Block) {
 184                 ir_node *pred = get_irn_n(node, -1);
 185                 if (pred->visited < irg->visited)
 186                         cnt += irg_walk_2_post(pred, post, env);
 187         }
 188         for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 189                 ir_node *pred = get_irn_n(node, i);
 190                 if (pred->visited < irg->visited)
 191                         cnt += irg_walk_2_post(pred, post, env);
 192         }
 193
 194         post(node, env);
 195
 196         return cnt;
 197 }
 198
 199 /**
 200  * specialized version of irg_walk_2, called if pre and post callbacks exist
 201  *
 202  * @return number of visited nodes
 203  */
 204 static unsigned irg_walk_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
 205 {
 206         int i;
 207         unsigned cnt = 1;
 208         ir_graph *irg = current_ir_graph;
 209
 210         set_irn_visited(node, irg->visited);
 211
 212         pre(node, env);
 213
 214         if (node->op != op_Block) {
 215                 ir_node *pred = get_irn_n(node, -1);
 216                 if (pred->visited < irg->visited)
 217                         cnt += irg_walk_2_both(pred, pre, post, env);
 218         }
 219         for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 220                 ir_node *pred = get_irn_n(node, i);
 221                 if (pred->visited < irg->visited)
 222                         cnt += irg_walk_2_both(pred, pre, post, env);
 223         }
 224
 225         post(node, env);
 226
 227         return cnt;
 228 }
 229
 230 /**
 231  * Intraprozedural graph walker.
 232  *
 233  * @return number of visited nodes
 234  */
 235 unsigned irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
 236                     void *env)
 237 {
 238         if (node->visited < current_ir_graph->visited) {
 239                 if      (!post) return irg_walk_2_pre (node, pre, env);
 240                 else if (!pre)  return irg_walk_2_post(node, post, env);
 241                 else            return irg_walk_2_both(node, pre, post, env);
 242         }
 243         return 0;
 244 }
 245
 246 /* a counter */
 247 static unsigned nodes_touched = 0;
 248
 249 /*
 250  * generic graph walker
 251  */
 252 void irg_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 253 {
 254         assert(is_ir_node(node));
 255
 256 #ifdef INTERPROCEDURAL_VIEW
 257         if (get_interprocedural_view()) {
 258                 pset_new_t           irg_set;
 259                 pset_new_iterator_t  iter;
 260                 ir_visited_t         visited;
 261                 ir_graph            *irg;
 262                 assert(get_irp_ip_view_state() == ip_view_valid);
 263
 264                 pset_new_init(&irg_set);
 265                 set_interprocedural_view(0);
 266                 pset_new_insert(&irg_set, current_ir_graph);
 267                 irg_walk(node, (irg_walk_func *) collect_irgs, NULL, &irg_set);
 268                 set_interprocedural_view(1);
 269                 visited = get_max_irg_visited() + 1;
 270
 271                 foreach_pset_new(&irg_set, irg, iter) {
 272                         set_irg_visited(irg, visited);
 273                 }
 274                 irg_walk_cg(node, visited, &irg_set, pre, post, env);
 275                 pset_new_destroy(&irg_set);
 276         } else {
 277 #endif
 278                 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
 279                 inc_irg_visited(current_ir_graph);
 280                 nodes_touched = irg_walk_2(node, pre, post, env);
 281                 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
 282 #ifdef INTERPROCEDURAL_VIEW
 283         }
 284 #endif
 285 }
 286
 287 /*
 288  * walk over a graph
 289  */
 290 void irg_walk_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
 291 {
 292         ir_graph * rem = current_ir_graph;
 293
 294         hook_irg_walk(irg, (generic_func *)pre, (generic_func *)post);
 295         current_ir_graph = irg;
 296         irg_walk(get_irg_end(irg), pre, post, env);
 297         irg->estimated_node_count = nodes_touched;
 298         current_ir_graph = rem;
 299 }
 300
 301 /* Executes irg_walk(end, pre, post, env) for all irgraphs in irprog.
 302    Sets current_ir_graph properly for each walk.  Conserves current
 303    current_ir_graph. */
 304 void all_irg_walk(irg_walk_func *pre, irg_walk_func *post, void *env)
 305 {
 306         int i, n;
 307         ir_graph *irg;
 308
 309         for (i = 0, n = get_irp_n_irgs(); i < n; i++) {
 310                 irg = get_irp_irg(i);
 311                 irg_walk_graph(irg, pre, post, env);
 312         }
 313 }
 314
 315 /***************************************************************************/
 316
 317 /**
 318  * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
 319  *
 320  * @return number of visited nodes
 321  */
 322 static unsigned irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env)
 323 {
 324         int i;
 325         unsigned cnt = 1;
 326         ir_graph *irg = current_ir_graph;
 327
 328         set_irn_visited(node, irg->visited);
 329
 330         pre(node, env);
 331
 332         if (node->op != op_Block) {
 333                 ir_node *pred = get_irn_n(node, -1);
 334                 if (pred->visited < irg->visited)
 335                         cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
 336         }
 337         for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
 338                 ir_node *pred = get_irn_in_or_dep(node, i);
 339                 if (pred->visited < irg->visited)
 340                         cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
 341         }
 342         return cnt;
 343 }
 344
 345 /**
 346  * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
 347  *
 348  * @return number of visited nodes
 349  */
 350 static unsigned irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env)
 351 {
 352         int i;
 353         unsigned cnt = 1;
 354         ir_graph *irg = current_ir_graph;
 355
 356         set_irn_visited(node, irg->visited);
 357
 358         if (node->op != op_Block) {
 359                 ir_node *pred = get_irn_n(node, -1);
 360                 if (pred->visited < irg->visited)
 361                         cnt += irg_walk_in_or_dep_2_post(pred, post, env);
 362         }
 363         for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
 364                 ir_node *pred = get_irn_in_or_dep(node, i);
 365                 if (pred->visited < irg->visited)
 366                         cnt += irg_walk_in_or_dep_2_post(pred, post, env);
 367         }
 368
 369         post(node, env);
 370
 371         return cnt;
 372 }
 373
 374 /**
 375  * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
 376  *
 377  * @return number of visited nodes
 378  */
 379 static unsigned irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 380 {
 381         int i;
 382         unsigned cnt = 1;
 383         ir_graph *irg = current_ir_graph;
 384
 385         set_irn_visited(node, irg->visited);
 386
 387         pre(node, env);
 388
 389         if (node->op != op_Block) {
 390                 ir_node *pred = get_irn_n(node, -1);
 391                 if (pred->visited < irg->visited)
 392                         cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
 393         }
 394         for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
 395                 ir_node *pred = get_irn_in_or_dep(node, i);
 396                 if (pred->visited < irg->visited)
 397                         cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
 398         }
 399
 400         post(node, env);
 401
 402         return cnt;
 403 }
 404
 405 /**
 406  * Intraprozedural graph walker. Follows dependency edges as well.
 407  *
 408  * @return number of visited nodes
 409  */
 410 static unsigned irg_walk_in_or_dep_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 411 {
 412         if (node->visited < current_ir_graph->visited) {
 413                 if      (! post) return irg_walk_in_or_dep_2_pre (node, pre, env);
 414                 else if (! pre)  return irg_walk_in_or_dep_2_post(node, post, env);
 415                 else             return irg_walk_in_or_dep_2_both(node, pre, post, env);
 416         }
 417         return 0;
 418 }
 419
 420 /*
 421  * Generic graph walker. Follows dependency edges as well.
 422  */
 423 void irg_walk_in_or_dep(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 424 {
 425         assert(is_ir_node(node));
 426
 427         if (get_interprocedural_view()) {
 428                 assert(0 && "This is not yet implemented.");
 429         } else {
 430                 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
 431                 inc_irg_visited(current_ir_graph);
 432                 nodes_touched = irg_walk_in_or_dep_2(node, pre, post, env);
 433                 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
 434         }
 435 }
 436
 437 /*
 438  * Walk over a graph. Follow all edges (including dependencies)
 439  */
 440 void irg_walk_in_or_dep_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
 441 {
 442         ir_graph * rem = current_ir_graph;
 443
 444         hook_irg_walk(irg, (generic_func *)pre, (generic_func *)post);
 445         current_ir_graph = irg;
 446         irg_walk_in_or_dep(get_irg_end(irg), pre, post, env);
 447         irg->estimated_node_count = nodes_touched;
 448         current_ir_graph = rem;
 449 }
 450
 451 /***************************************************************************/
 452
 453 /**
 454  * Returns current_ir_graph and sets it to the irg of predecessor index
 455  * of node n.
 456  */
 457 static inline ir_graph * switch_irg(ir_node *n, int index)
 458 {
 459         ir_graph *old_current = current_ir_graph;
 460
 461         if (get_interprocedural_view()) {
 462                 /* Only Filter and Block nodes can have predecessors in other graphs. */
 463                 if (is_Filter(n))
 464                         n = get_nodes_block(n);
 465                 if (is_Block(n)) {
 466                         ir_node *cfop = skip_Proj(get_Block_cfgpred(n, index));
 467                         if (is_ip_cfop(cfop)) {
 468                                 current_ir_graph = get_irn_irg(cfop);
 469                         }
 470                 }
 471         }
 472
 473         return old_current;
 474 }
 475
 476 #ifdef INTERPROCEDURAL_VIEW
 477 static void cg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
 478 {
 479         int i;
 480         ir_graph *rem = NULL;
 481         assert(node);
 482
 483         if (get_irn_visited(node) < get_irg_visited(current_ir_graph)) {
 484                 set_irn_visited(node, get_irg_visited(current_ir_graph));
 485
 486                 if (pre) pre(node, env);
 487
 488                 if (is_no_Block(node))
 489                         cg_walk_2(get_nodes_block(node), pre, post, env);
 490                 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 491                         rem = switch_irg(node, i);  /* @@@ AS: Is this wrong? We do have to
 492                                                     switch to the irg of the predecessor, don't we? */
 493                         cg_walk_2(get_irn_n(node, i), pre, post, env);
 494                         current_ir_graph = rem;
 495                 }
 496
 497                 if (post) post(node, env);
 498         }
 499 }
 500
 501 /* Walks all irgs in interprocedural view.  Visits each node only once. */
 502 void cg_walk(irg_walk_func *pre, irg_walk_func *post, void *env)
 503 {
 504         int i;
 505         ir_graph *rem = current_ir_graph;
 506         int rem_view = get_interprocedural_view();
 507
 508         set_interprocedural_view(1);
 509
 510         inc_max_irg_visited();
 511         /* Fix all irg_visited flags */
 512         for (i = 0; i < get_irp_n_irgs(); i++)
 513                 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
 514
 515         /* Walk starting at unreachable procedures. Only these
 516          * have End blocks visible in interprocedural view. */
 517         for (i = 0; i < get_irp_n_irgs(); i++) {
 518                 ir_node *sb;
 519                 current_ir_graph = get_irp_irg(i);
 520
 521                 sb = get_irg_start_block(current_ir_graph);
 522
 523                 if ((get_Block_n_cfgpreds(sb) > 1) ||
 524                         (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
 525
 526                 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
 527         }
 528
 529         /* Check whether we walked all procedures: there could be procedures
 530            with cyclic calls but no call from the outside. */
 531         for (i = 0; i < get_irp_n_irgs(); i++) {
 532                 ir_node *sb;
 533                 current_ir_graph = get_irp_irg(i);
 534
 535                 /* Test start block: if inner procedure end and end block are not
 536                 * visible and therefore not marked. */
 537                 sb = get_irg_start_block(current_ir_graph);
 538                 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
 539                         cg_walk_2(sb, pre, post, env);
 540                 }
 541         }
 542
 543         /* Walk all endless loops in inner procedures.
 544          * We recognize an inner procedure if the End node is not visited. */
 545         for (i = 0; i < get_irp_n_irgs(); i++) {
 546                 ir_node *e;
 547                 current_ir_graph = get_irp_irg(i);
 548                 e = get_irg_end(current_ir_graph);
 549                 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
 550                         int j;
 551                         /* Don't visit the End node. */
 552                         for (j = 0; j < get_End_n_keepalives(e); j++)
 553                                 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
 554                 }
 555         }
 556
 557         set_interprocedural_view(rem_view);
 558         current_ir_graph = rem;
 559 }
 560 #endif
 561
 562
 563 /***************************************************************************/
 564
 565 /* Walks back from n until it finds a real cf op. */
 566 static ir_node *get_cf_op(ir_node *n)
 567 {
 568         while (!is_cfop(n) && !is_fragile_op(n) && !is_Bad(n)) {
 569                 n = skip_Id(n);
 570                 n = skip_Tuple(n);
 571                 n = skip_Proj(n);
 572         }
 573         return n;
 574 }
 575
 576 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 577 {
 578         int i;
 579
 580         if (!Block_block_visited(node)) {
 581                 mark_Block_block_visited(node);
 582
 583                 if (pre) pre(node, env);
 584
 585                 for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
 586                         /* find the corresponding predecessor block. */
 587                         ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
 588                         pred = get_nodes_block(pred);
 589                         if (get_irn_opcode(pred) == iro_Block) {
 590                                 /* recursion */
 591                                 irg_block_walk_2(pred, pre, post, env);
 592                         }
 593                         else {
 594                                 assert(get_irn_opcode(pred) == iro_Bad);
 595                         }
 596                 }
 597
 598                 if (post) post(node, env);
 599         }
 600 }
 601
 602
 603 /* walks only over Block nodes in the graph.  Has it's own visited
 604    flag, so that it can be interleaved with the other walker.         */
 605 void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 606 {
 607         ir_graph *irg = current_ir_graph;
 608         ir_node *block, *pred;
 609         int i;
 610
 611         hook_irg_block_walk(irg, node, (generic_func *)pre, (generic_func *)post);
 612
 613         assert(node);
 614         assert(!get_interprocedural_view());   /* interprocedural_view not implemented, because it
 615                                                 * interleaves with irg_walk */
 616         ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
 617         inc_irg_block_visited(irg);
 618         block = is_Block(node) ? node : get_nodes_block(node);
 619         assert(is_Block(block));
 620         irg_block_walk_2(block, pre, post, env);
 621
 622         /* keepalive: the endless loops ... */
 623         if (is_End(node)) {
 624                 int arity = get_irn_arity(node);
 625                 for (i = 0; i < arity; i++) {
 626                         pred = get_irn_n(node, i);
 627                         if (!is_Block(pred)) {
 628                                 pred = get_nodes_block(pred);
 629                                 if (!is_Block(pred)) {
 630                                         /* if rare cases a kept node might have a bad block input */
 631                                         continue;
 632                                 }
 633                         }
 634                         /* Sometimes the blocks died, but are still reachable through kept nodes.
 635                          * Make sure the algorithms that try to remove these reach them. */
 636                         irg_block_walk_2(pred, pre, post, env);
 637                 }
 638         }
 639
 640         ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
 641 }
 642
 643 /*
 644  * walk over a graph block wise
 645  */
 646 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
 647               irg_walk_func *post, void *env) {
 648         ir_graph * rem = current_ir_graph;
 649         current_ir_graph = irg;
 650         irg_block_walk(get_irg_end(irg), pre, post, env);
 651         current_ir_graph = rem;
 652 }
 653
 654 /*
 655  * Additionally walk over all anchors. Do NOT increase the visit flag.
 656  */
 657 void irg_walk_anchors(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
 658 {
 659         ir_graph * rem = current_ir_graph;
 660         current_ir_graph = irg;
 661
 662         inc_irg_visited(irg);
 663         irg_walk_2(irg->anchor, pre, post, env);
 664
 665         current_ir_graph = rem;
 666 }
 667
 668 /********************************************************************/
 669
 670 typedef struct walk_env {
 671         irg_walk_func *pre;
 672         irg_walk_func *post;
 673         void *env;
 674 } walk_env;
 675
 676 static void walk_initializer(ir_initializer_t *initializer, walk_env *env)
 677 {
 678         switch (initializer->kind) {
 679     case IR_INITIALIZER_CONST:
 680         irg_walk(initializer->consti.value, env->pre, env->post, env->env);
 681         return;
 682     case IR_INITIALIZER_TARVAL:
 683     case IR_INITIALIZER_NULL:
 684         return;
 685
 686     case IR_INITIALIZER_COMPOUND: {
 687         size_t i;
 688         for (i = 0; i < initializer->compound.n_initializers; ++i) {
 689             ir_initializer_t *subinitializer
 690                 = initializer->compound.initializers[i];
 691             walk_initializer(subinitializer, env);
 692         }
 693         return;
 694     }
 695         }
 696         panic("invalid initializer found");
 697 }
 698
 699 /**
 700  * Walk to all constant expressions in this entity.
 701  */
 702 static void walk_entity(ir_entity *ent, void *env)
 703 {
 704         walk_env *my_env = (walk_env *)env;
 705
 706         if (ent->initializer != NULL) {
 707                 walk_initializer(ent->initializer, my_env);
 708         } else if (entity_has_compound_ent_values(ent)) {
 709                 int i, n_vals = get_compound_ent_n_values(ent);
 710
 711                 for (i = 0; i < n_vals; i++)
 712                         irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
 713         }
 714 }
 715
 716 /* Walks over all code in const_code_irg. */
 717 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env)
 718 {
 719         int i, j, n_types;
 720         walk_env my_env;
 721         ir_segment_t s;
 722
 723         ir_graph *rem = current_ir_graph;
 724         current_ir_graph = get_const_code_irg();
 725         inc_irg_visited(current_ir_graph);
 726
 727         my_env.pre = pre;
 728         my_env.post = post;
 729         my_env.env = env;
 730
 731         /* Walk all types that can contain constant entities.  */
 732         for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; s++)
 733                 walk_types_entities(get_segment_type(s), &walk_entity, &my_env);
 734         n_types = get_irp_n_types();
 735         for (i = 0; i < n_types; i++)
 736                 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
 737         for (i = 0; i < get_irp_n_irgs(); i++)
 738                 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
 739
 740         /* Walk constant array bounds. */
 741         for (i = 0; i < n_types; i++) {
 742                 ir_type *tp = get_irp_type(i);
 743                 if (is_Array_type(tp)) {
 744                         int n_dim = get_array_n_dimensions(tp);
 745                         for (j = 0; j < n_dim; j++) {
 746                                 ir_node *n = get_array_lower_bound(tp, j);
 747                                 if (n) irg_walk(n, pre, post, env);
 748                                 n = get_array_upper_bound(tp, j);
 749                                 if (n) irg_walk(n, pre, post, env);
 750                         }
 751                 }
 752         }
 753
 754         current_ir_graph = rem;
 755 }