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