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"
  40 #include "irprog.h"
  41 #include "irgwalk.h"
  42 #include "irhooks.h"
  43 #include "ircgcons.h"
  44 #include "entity_t.h"
  45
  46 #include "error.h"
  47 #include "pset_new.h"
  48 #include "array.h"
  49
  50 /**
  51  * Walk over an interprocedural graph (callgraph).
  52  * Visits only graphs in irg_set.
  53  */
  54 static void irg_walk_cg(ir_node * node, unsigned long visited,
  55                         pset_new_t *irg_set, irg_walk_func *pre,
  56                         irg_walk_func *post, void * env) {
  57         int i;
  58         ir_graph * rem = current_ir_graph;
  59         ir_node * pred;
  60
  61         assert(node && node->kind == k_ir_node);
  62         if (get_irn_visited(node) >= visited) return;
  63
  64         set_irn_visited(node, visited);
  65
  66         if (pre) pre(node, env);
  67
  68         pred = skip_Proj(node);
  69         if (get_irn_op(pred) == op_CallBegin
  70                 || get_irn_op(pred) == op_EndReg
  71                 || get_irn_op(pred) == op_EndExcept) {
  72                         current_ir_graph = get_irn_irg(pred);
  73         }
  74
  75         if (is_no_Block(node)) { /* not block */
  76                 irg_walk_cg(get_nodes_block(node), visited, irg_set, pre, post, env);
  77         }
  78
  79         if (get_irn_op(node) == op_Block) { /* block */
  80                 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
  81                         ir_node * exec = get_irn_n(node, i);
  82                         ir_node * pred = skip_Proj(exec);
  83                         if ((get_irn_op(pred) != op_CallBegin
  84                                 && get_irn_op(pred) != op_EndReg
  85                                 && get_irn_op(pred) != op_EndExcept)
  86                                 || pset_new_contains(irg_set, get_irn_irg(pred))) {
  87                                         irg_walk_cg(exec, visited, irg_set, pre, post, env);
  88                         }
  89                 }
  90         } else if (get_irn_op(node) == op_Filter) { /* filter */
  91                 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
  92                         ir_node * pred = get_irn_n(node, i);
  93                         if (get_irn_op(pred) == op_Unknown || get_irn_op(pred) == op_Bad) {
  94                                 irg_walk_cg(pred, visited, irg_set, pre, post, env);
  95                         } else {
  96                                 ir_node * exec;
  97                                 exec = skip_Proj(get_Block_cfgpred(get_nodes_block(node), i));
  98
  99                                 if (op_Bad == get_irn_op (exec)) {
 100                                         continue;
 101                                 }
 102
 103                                 assert(get_irn_op(exec) == op_CallBegin
 104                                         || get_irn_op(exec) == op_EndReg
 105                                         || get_irn_op(exec) == op_EndExcept);
 106                                 if (pset_new_contains(irg_set, get_irn_irg(exec))) {
 107                                         current_ir_graph = get_irn_irg(exec);
 108                                         irg_walk_cg(pred, visited, irg_set, pre, post, env);
 109                                         current_ir_graph = rem;
 110                                 }
 111                         }
 112                 }
 113         } else {                      /* everything else */
 114                 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 115                         irg_walk_cg(get_irn_n(node, i), visited, irg_set, pre, post, env);
 116                 }
 117         }
 118
 119         if (post) post(node, env);
 120
 121         current_ir_graph = rem;
 122 }
 123
 124
 125 /**
 126  * Insert all ir_graphs in irg_set, that are (transitive) reachable.
 127  */
 128 static void collect_irgs(ir_node * node, pset_new_t *irg_set) {
 129         if (is_Call(node)) {
 130                 int i;
 131                 for (i = get_Call_n_callees(node) - 1; i >= 0; --i) {
 132                         ir_entity * ent = get_Call_callee(node, i);
 133                         ir_graph * irg = get_entity_irg(ent);
 134                         if (irg && !pset_new_contains(irg_set, irg)) {
 135                                 pset_new_insert(irg_set, irg);
 136                                 irg_walk_graph(irg, (irg_walk_func *) collect_irgs, NULL, irg_set);
 137                         }
 138                 }
 139         }
 140 }
 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
 148 irg_walk_2_pre(ir_node *node, irg_walk_func *pre, void * env) {
 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
 176 irg_walk_2_post(ir_node *node, irg_walk_func *post, void * env) {
 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
 205 irg_walk_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env) {
 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 static unsigned
 236 irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, 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                 unsigned long        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                 set_using_irn_visited(current_ir_graph);
 279                 inc_irg_visited(current_ir_graph);
 280                 nodes_touched = irg_walk_2(node, pre, post, env);
 281                 clear_using_irn_visited(current_ir_graph);
 282 #ifdef INTERPROCEDURAL_VIEW
 283         }
 284 #endif
 285         return;
 286 }
 287
 288 /*
 289  * walk over a graph
 290  */
 291 void irg_walk_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
 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         int i, n;
 306         ir_graph *irg;
 307
 308         for (i = 0, n = get_irp_n_irgs(); i < n; i++) {
 309                 irg = get_irp_irg(i);
 310                 irg_walk_graph(irg, pre, post, env);
 311         }
 312 }
 313
 314 /***************************************************************************/
 315
 316 /**
 317  * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
 318  *
 319  * @return number of visited nodes
 320  */
 321 static unsigned
 322 irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env) {
 323         int i;
 324         unsigned cnt = 1;
 325         ir_graph *irg = current_ir_graph;
 326
 327         set_irn_visited(node, irg->visited);
 328
 329         pre(node, env);
 330
 331         if (node->op != op_Block) {
 332                 ir_node *pred = get_irn_n(node, -1);
 333                 if (pred->visited < irg->visited)
 334                         cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
 335         }
 336         for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
 337                 ir_node *pred = get_irn_in_or_dep(node, i);
 338                 if (pred->visited < irg->visited)
 339                         cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
 340         }
 341         return cnt;
 342 }
 343
 344 /**
 345  * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
 346  *
 347  * @return number of visited nodes
 348  */
 349 static unsigned
 350 irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env) {
 351         int i;
 352         unsigned cnt = 1;
 353         ir_graph *irg = current_ir_graph;
 354
 355         set_irn_visited(node, irg->visited);
 356
 357         if (node->op != op_Block) {
 358                 ir_node *pred = get_irn_n(node, -1);
 359                 if (pred->visited < irg->visited)
 360                         cnt += irg_walk_in_or_dep_2_post(pred, post, env);
 361         }
 362         for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
 363                 ir_node *pred = get_irn_in_or_dep(node, i);
 364                 if (pred->visited < irg->visited)
 365                         cnt += irg_walk_in_or_dep_2_post(pred, post, env);
 366         }
 367
 368         post(node, env);
 369
 370         return cnt;
 371 }
 372
 373 /**
 374  * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
 375  *
 376  * @return number of visited nodes
 377  */
 378 static unsigned
 379 irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env) {
 380         int i;
 381         unsigned cnt = 1;
 382         ir_graph *irg = current_ir_graph;
 383
 384         set_irn_visited(node, irg->visited);
 385
 386         pre(node, env);
 387
 388         if (node->op != op_Block) {
 389                 ir_node *pred = get_irn_n(node, -1);
 390                 if (pred->visited < irg->visited)
 391                         cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
 392         }
 393         for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
 394                 ir_node *pred = get_irn_in_or_dep(node, i);
 395                 if (pred->visited < irg->visited)
 396                         cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
 397         }
 398
 399         post(node, env);
 400
 401         return cnt;
 402 }
 403
 404 /**
 405  * Intraprozedural graph walker. Follows dependency edges as well.
 406  *
 407  * @return number of visited nodes
 408  */
 409 static unsigned
 410 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                 set_using_irn_visited(current_ir_graph);
 431                 inc_irg_visited(current_ir_graph);
 432                 nodes_touched = irg_walk_in_or_dep_2(node, pre, post, env);
 433                 clear_using_irn_visited(current_ir_graph);
 434         }
 435         return;
 436 }
 437
 438 /*
 439  * Walk over a graph. Follow all edges (including dependencies)
 440  */
 441 void irg_walk_in_or_dep_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
 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 *
 458 switch_irg(ir_node *n, int index) {
 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 (get_irn_op(n) == op_Filter)
 464                         n = get_nodes_block(n);
 465                 if (get_irn_op(n) == op_Block) {
 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 static void
 477 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         return;
 500 }
 501
 502 #ifdef INTERPROCEDURAL_VIEW
 503 /* Walks all irgs in interprocedural view.  Visits each node only once. */
 504 void cg_walk(irg_walk_func *pre, irg_walk_func *post, void *env) {
 505         int i;
 506         ir_graph *rem = current_ir_graph;
 507         int rem_view = get_interprocedural_view();
 508
 509         set_interprocedural_view(1);
 510
 511         inc_max_irg_visited();
 512         /* Fix all irg_visited flags */
 513         for (i = 0; i < get_irp_n_irgs(); i++)
 514                 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
 515
 516         /* Walk starting at unreachable procedures. Only these
 517          * have End blocks visible in interprocedural view. */
 518         for (i = 0; i < get_irp_n_irgs(); i++) {
 519                 ir_node *sb;
 520                 current_ir_graph = get_irp_irg(i);
 521
 522                 sb = get_irg_start_block(current_ir_graph);
 523
 524                 if ((get_Block_n_cfgpreds(sb) > 1) ||
 525                         (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
 526
 527                 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
 528         }
 529
 530         /* Check whether we walked all procedures: there could be procedures
 531            with cyclic calls but no call from the outside. */
 532         for (i = 0; i < get_irp_n_irgs(); i++) {
 533                 ir_node *sb;
 534                 current_ir_graph = get_irp_irg(i);
 535
 536                 /* Test start block: if inner procedure end and end block are not
 537                 * visible and therefore not marked. */
 538                 sb = get_irg_start_block(current_ir_graph);
 539                 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
 540                         cg_walk_2(sb, pre, post, env);
 541                 }
 542         }
 543
 544         /* Walk all endless loops in inner procedures.
 545          * We recognize an inner procedure if the End node is not visited. */
 546         for (i = 0; i < get_irp_n_irgs(); i++) {
 547                 ir_node *e;
 548                 current_ir_graph = get_irp_irg(i);
 549                 e = get_irg_end(current_ir_graph);
 550                 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
 551                         int j;
 552                         /* Don't visit the End node. */
 553                         for (j = 0; j < get_End_n_keepalives(e); j++)
 554                                 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
 555                 }
 556         }
 557
 558         set_interprocedural_view(rem_view);
 559         current_ir_graph = rem;
 560 }
 561 #endif
 562
 563
 564 /***************************************************************************/
 565
 566 /* Walks back from n until it finds a real cf op. */
 567 static ir_node *get_cf_op(ir_node *n) {
 568         ir_node *pred;
 569
 570         n = skip_Id(n);
 571         n = skip_Tuple(n);
 572         pred = skip_Proj(n);
 573         if (!(is_cfop(pred) || is_fragile_op(pred) || is_Bad(pred)))
 574                 n = get_cf_op(n);
 575
 576         return skip_Proj(n);
 577 }
 578
 579 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 580 {
 581         int i;
 582
 583         if (Block_not_block_visited(node)) {
 584                 mark_Block_block_visited(node);
 585
 586                 if(pre) pre(node, env);
 587
 588                 for(i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
 589                         /* find the corresponding predecessor block. */
 590                         ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
 591                         pred = get_nodes_block(pred);
 592                         if(get_irn_opcode(pred) == iro_Block) {
 593                                 /* recursion */
 594                                 irg_block_walk_2(pred, pre, post, env);
 595                         }
 596                         else {
 597                                 assert(get_irn_opcode(pred) == iro_Bad);
 598                         }
 599                 }
 600
 601                 if(post) post(node, env);
 602         }
 603 }
 604
 605
 606 /* walks only over Block nodes in the graph.  Has it's own visited
 607    flag, so that it can be interleaved with the other walker.         */
 608 void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
 609 {
 610         ir_node *block, *pred;
 611         int i;
 612
 613         hook_irg_block_walk(current_ir_graph, node, (generic_func *)pre, (generic_func *)post);
 614
 615         assert(node);
 616         assert(!get_interprocedural_view());   /* interprocedural_view not implemented, because it
 617                                                * interleaves with irg_walk */
 618         set_using_block_visited(current_ir_graph);
 619         inc_irg_block_visited(current_ir_graph);
 620         block = is_Block(node) ? node : get_nodes_block(node);
 621         assert(get_irn_op(block) == op_Block);
 622         irg_block_walk_2(block, pre, post, env);
 623
 624         /* keepalive: the endless loops ... */
 625         if (get_irn_op(node) == op_End) {
 626                 int arity = get_irn_arity(node);
 627                 for (i = 0; i < arity; i++) {
 628                         pred = get_irn_n(node, i);
 629                         if (get_irn_op(pred) == op_Block)
 630                                 irg_block_walk_2(pred, pre, post, env);
 631                 }
 632                 /* Sometimes the blocks died, but are still reachable through Phis.
 633                 * Make sure the algorithms that try to remove these reach them. */
 634                 for (i = 0; i < arity; i++) {
 635                         pred = get_irn_n(node, i);
 636                         if (get_irn_op(pred) == op_Phi) {
 637                                 ir_node *block = get_nodes_block(pred);
 638
 639                                 if (! is_Bad(block))
 640                                         irg_block_walk_2(block, pre, post, env);
 641                         }
 642                 }
 643         }
 644
 645         clear_using_block_visited(current_ir_graph);
 646 }
 647
 648 /*
 649  * walk over a graph block wise
 650  */
 651 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
 652               irg_walk_func *post, void *env) {
 653         ir_graph * rem = current_ir_graph;
 654         current_ir_graph = irg;
 655         irg_block_walk(get_irg_end(irg), pre, post, env);
 656         current_ir_graph = rem;
 657 }
 658
 659 /*
 660  * Additionally walk over all anchors. Do NOT increase the visit flag.
 661  */
 662 void irg_walk_anchors(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
 663         ir_graph * rem = current_ir_graph;
 664         current_ir_graph = irg;
 665
 666         inc_irg_visited(irg);
 667         irg_walk_2(irg->anchor, pre, post, env);
 668
 669         current_ir_graph = rem;
 670 }
 671
 672 /********************************************************************/
 673
 674 typedef struct walk_env {
 675         irg_walk_func *pre;
 676         irg_walk_func *post;
 677         void *env;
 678 } walk_env;
 679
 680 static void walk_initializer(ir_initializer_t *initializer, walk_env *env)
 681 {
 682         switch(initializer->kind) {
 683     case IR_INITIALIZER_CONST:
 684         irg_walk(initializer->consti.value, env->pre, env->post, env->env);
 685         return;
 686     case IR_INITIALIZER_TARVAL:
 687     case IR_INITIALIZER_NULL:
 688         return;
 689
 690     case IR_INITIALIZER_COMPOUND: {
 691         size_t i;
 692         for(i = 0; i < initializer->compound.n_initializers; ++i) {
 693             ir_initializer_t *subinitializer
 694                 = initializer->compound.initializers[i];
 695             walk_initializer(subinitializer, env);
 696         }
 697         return;
 698     }
 699         }
 700         panic("invalid initializer found");
 701 }
 702
 703 /**
 704  * Walk to all constant expressions in this entity.
 705  */
 706 static void walk_entity(ir_entity *ent, void *env)
 707 {
 708         walk_env *my_env = (walk_env *)env;
 709
 710         if (get_entity_variability(ent) != variability_uninitialized) {
 711                 if (ent->has_initializer) {
 712                         walk_initializer(ent->attr.initializer, my_env);
 713                 } else if (is_atomic_entity(ent)) {
 714                         irg_walk(get_atomic_ent_value(ent), my_env->pre, my_env->post, my_env->env);
 715                 } else {
 716                         int i, n_vals = get_compound_ent_n_values(ent);
 717
 718                         for (i = 0; i < n_vals; i++)
 719                                 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
 720                 }
 721         }
 722 }
 723
 724 /* Walks over all code in const_code_irg. */
 725 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env) {
 726         int i, j, n_types;
 727         walk_env my_env;
 728
 729         ir_graph *rem = current_ir_graph;
 730         current_ir_graph = get_const_code_irg();
 731         inc_irg_visited(current_ir_graph);
 732
 733         my_env.pre = pre;
 734         my_env.post = post;
 735         my_env.env = env;
 736
 737         /* Walk all types that can contain constant entities.  */
 738         walk_types_entities(get_glob_type(), &walk_entity, &my_env);
 739         n_types = get_irp_n_types();
 740         for (i = 0; i < n_types; i++)
 741                 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
 742         for (i = 0; i < get_irp_n_irgs(); i++)
 743                 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
 744
 745         /* Walk constant array bounds. */
 746         for (i = 0; i < n_types; i++) {
 747                 ir_type *tp = get_irp_type(i);
 748                 if (is_Array_type(tp)) {
 749                         int n_dim = get_array_n_dimensions(tp);
 750                         for (j = 0; j < n_dim; j++) {
 751                                 ir_node *n = get_array_lower_bound(tp, j);
 752                                 if (n) irg_walk(n, pre, post, env);
 753                                 n = get_array_upper_bound(tp, j);
 754                                 if (n) irg_walk(n, pre, post, env);
 755                         }
 756                 }
 757         }
 758
 759         current_ir_graph = rem;
 760 }