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