2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
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.
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.
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
22 * @brief Functions for traversing ir graphs
23 * @author Boris Boesler, Goetz Lindenmaier, Michael Beck
26 * traverse an ir graph
27 * - execute the pre function before recursion
28 * - execute the post function after recursion
35 #include "irgraph_t.h"
47 * Walk over an interprocedural graph (callgraph).
48 * Visits only graphs in irg_set.
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) {
54 ir_graph * rem = current_ir_graph;
57 assert(node && node->kind == k_ir_node);
58 if (get_irn_visited(node) >= visited) return;
60 set_irn_visited(node, visited);
62 if (pre) pre(node, env);
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);
71 if (is_no_Block(node)) { /* not block */
72 irg_walk_cg(get_nodes_block(node), visited, irg_set, pre, post, env);
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);
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);
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);
94 exec = skip_Proj(get_Block_cfgpred(get_nodes_block(node), i));
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;
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);
116 if (post) post(node, env);
118 current_ir_graph = rem;
123 * Insert all ir_graphs in irg_set, that are (transitive) reachable.
125 static void collect_irgs(ir_node * node, pset_new_t *irg_set) {
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);
140 * specialized version of irg_walk_2, called if only pre callback exists
142 * @return number of visited nodes
145 irg_walk_2_pre(ir_node *node, irg_walk_func *pre, void * env) {
148 ir_graph *irg = current_ir_graph;
150 set_irn_visited(node, irg->visited);
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);
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);
168 * specialized version of irg_walk_2, called if only post callback exists
170 * @return number of visited nodes
173 irg_walk_2_post(ir_node *node, irg_walk_func *post, void * env) {
176 ir_graph *irg = current_ir_graph;
178 set_irn_visited(node, irg->visited);
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);
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);
197 * specialized version of irg_walk_2, called if pre and post callbacks exist
199 * @return number of visited nodes
202 irg_walk_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env) {
205 ir_graph *irg = current_ir_graph;
207 set_irn_visited(node, irg->visited);
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);
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);
228 * Intraprozedural graph walker.
230 * @return number of visited nodes
233 irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
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);
244 static unsigned nodes_touched = 0;
247 * generic graph walker
249 void irg_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
251 assert(is_ir_node(node));
253 #ifdef INTERPROCEDURAL_VIEW
254 if (get_interprocedural_view()) {
256 pset_new_iterator_t iter;
257 ir_visited_t visited;
259 assert(get_irp_ip_view_state() == ip_view_valid);
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;
268 foreach_pset_new(&irg_set, irg, iter) {
269 set_irg_visited(irg, visited);
271 irg_walk_cg(node, visited, &irg_set, pre, post, env);
272 pset_new_destroy(&irg_set);
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
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;
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;
297 /* Executes irg_walk(end, pre, post, env) for all irgraphs in irprog.
298 Sets current_ir_graph properly for each walk. Conserves current
300 void all_irg_walk(irg_walk_func *pre, irg_walk_func *post, void *env) {
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);
310 /***************************************************************************/
313 * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
315 * @return number of visited nodes
318 irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env) {
321 ir_graph *irg = current_ir_graph;
323 set_irn_visited(node, irg->visited);
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);
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);
341 * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
343 * @return number of visited nodes
346 irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env) {
349 ir_graph *irg = current_ir_graph;
351 set_irn_visited(node, irg->visited);
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);
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);
370 * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
372 * @return number of visited nodes
375 irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env) {
378 ir_graph *irg = current_ir_graph;
380 set_irn_visited(node, irg->visited);
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);
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);
401 * Intraprozedural graph walker. Follows dependency edges as well.
403 * @return number of visited nodes
406 irg_walk_in_or_dep_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
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);
417 * Generic graph walker. Follows dependency edges as well.
419 void irg_walk_in_or_dep(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
421 assert(is_ir_node(node));
423 if (get_interprocedural_view()) {
424 assert(0 && "This is not yet implemented.");
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);
434 * Walk over a graph. Follow all edges (including dependencies)
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;
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;
446 /***************************************************************************/
449 * Returns current_ir_graph and sets it to the irg of predecessor index
452 static inline ir_graph *
453 switch_irg(ir_node *n, int index) {
454 ir_graph *old_current = current_ir_graph;
456 if (get_interprocedural_view()) {
457 /* Only Filter and Block nodes can have predecessors in other graphs. */
459 n = get_nodes_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);
472 cg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
475 ir_graph *rem = NULL;
478 if (get_irn_visited(node) < get_irg_visited(current_ir_graph)) {
479 set_irn_visited(node, get_irg_visited(current_ir_graph));
481 if (pre) pre(node, env);
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;
492 if (post) post(node, env);
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) {
500 ir_graph *rem = current_ir_graph;
501 int rem_view = get_interprocedural_view();
503 set_interprocedural_view(1);
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());
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++) {
514 current_ir_graph = get_irp_irg(i);
516 sb = get_irg_start_block(current_ir_graph);
518 if ((get_Block_n_cfgpreds(sb) > 1) ||
519 (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
521 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
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++) {
528 current_ir_graph = get_irp_irg(i);
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);
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++) {
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)) {
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);
552 set_interprocedural_view(rem_view);
553 current_ir_graph = rem;
558 /***************************************************************************/
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)) {
570 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
574 if (!Block_block_visited(node)) {
575 mark_Block_block_visited(node);
577 if (pre) pre(node, env);
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) {
585 irg_block_walk_2(pred, pre, post, env);
588 assert(get_irn_opcode(pred) == iro_Bad);
592 if (post) post(node, env);
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)
601 ir_graph *irg = current_ir_graph;
602 ir_node *block, *pred;
605 hook_irg_block_walk(irg, node, (generic_func *)pre, (generic_func *)post);
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);
616 /* keepalive: the endless loops ... */
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 pred = get_nodes_block(pred);
623 if (!is_Block(pred)) {
624 /* if rare cases a kept node might have a bad block input */
628 /* Sometimes the blocks died, but are still reachable through kept nodes.
629 * Make sure the algorithms that try to remove these reach them. */
630 irg_block_walk_2(pred, pre, post, env);
634 ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
638 * walk over a graph block wise
640 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
641 irg_walk_func *post, void *env) {
642 ir_graph * rem = current_ir_graph;
643 current_ir_graph = irg;
644 irg_block_walk(get_irg_end(irg), pre, post, env);
645 current_ir_graph = rem;
649 * Additionally walk over all anchors. Do NOT increase the visit flag.
651 void irg_walk_anchors(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
652 ir_graph * rem = current_ir_graph;
653 current_ir_graph = irg;
655 inc_irg_visited(irg);
656 irg_walk_2(irg->anchor, pre, post, env);
658 current_ir_graph = rem;
661 /********************************************************************/
663 typedef struct walk_env {
669 static void walk_initializer(ir_initializer_t *initializer, walk_env *env)
671 switch(initializer->kind) {
672 case IR_INITIALIZER_CONST:
673 irg_walk(initializer->consti.value, env->pre, env->post, env->env);
675 case IR_INITIALIZER_TARVAL:
676 case IR_INITIALIZER_NULL:
679 case IR_INITIALIZER_COMPOUND: {
681 for(i = 0; i < initializer->compound.n_initializers; ++i) {
682 ir_initializer_t *subinitializer
683 = initializer->compound.initializers[i];
684 walk_initializer(subinitializer, env);
689 panic("invalid initializer found");
693 * Walk to all constant expressions in this entity.
695 static void walk_entity(ir_entity *ent, void *env)
697 walk_env *my_env = (walk_env *)env;
699 if (get_entity_variability(ent) != variability_uninitialized) {
700 if (ent->has_initializer) {
701 walk_initializer(ent->attr.initializer, my_env);
702 } else if (is_atomic_entity(ent)) {
703 irg_walk(get_atomic_ent_value(ent), my_env->pre, my_env->post, my_env->env);
705 int i, n_vals = get_compound_ent_n_values(ent);
707 for (i = 0; i < n_vals; i++)
708 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
713 /* Walks over all code in const_code_irg. */
714 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env) {
718 ir_graph *rem = current_ir_graph;
719 current_ir_graph = get_const_code_irg();
720 inc_irg_visited(current_ir_graph);
726 /* Walk all types that can contain constant entities. */
727 walk_types_entities(get_glob_type(), &walk_entity, &my_env);
728 n_types = get_irp_n_types();
729 for (i = 0; i < n_types; i++)
730 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
731 for (i = 0; i < get_irp_n_irgs(); i++)
732 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
734 /* Walk constant array bounds. */
735 for (i = 0; i < n_types; i++) {
736 ir_type *tp = get_irp_type(i);
737 if (is_Array_type(tp)) {
738 int n_dim = get_array_n_dimensions(tp);
739 for (j = 0; j < n_dim; j++) {
740 ir_node *n = get_array_lower_bound(tp, j);
741 if (n) irg_walk(n, pre, post, env);
742 n = get_array_upper_bound(tp, j);
743 if (n) irg_walk(n, pre, post, env);
748 current_ir_graph = rem;