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"
46 #ifdef INTERPROCEDURAL_VIEW
48 * Walk over an interprocedural graph (callgraph).
49 * Visits only graphs in irg_set.
51 static void irg_walk_cg(ir_node * node, ir_visited_t visited,
52 pset_new_t *irg_set, irg_walk_func *pre,
53 irg_walk_func *post, void * env)
56 ir_graph * rem = current_ir_graph;
59 assert(node && node->kind == k_ir_node);
60 if (get_irn_visited(node) >= visited) return;
62 set_irn_visited(node, visited);
64 if (pre) pre(node, env);
66 pred = skip_Proj(node);
67 if (is_CallBegin(pred) ||
68 get_irn_op(pred) == op_EndReg ||
69 get_irn_op(pred) == op_EndExcept) {
70 current_ir_graph = get_irn_irg(pred);
73 if (is_no_Block(node)) { /* not block */
74 irg_walk_cg(get_nodes_block(node), visited, irg_set, pre, post, env);
77 if (is_Block(node)) { /* block */
78 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
79 ir_node * exec = get_irn_n(node, i);
80 ir_node * pred = skip_Proj(exec);
82 !is_CallBegin(pred) &&
83 get_irn_op(pred) != op_EndReg &&
84 get_irn_op(pred) != op_EndExcept
85 ) || pset_new_contains(irg_set, get_irn_irg(pred))) {
86 irg_walk_cg(exec, visited, irg_set, pre, post, env);
89 } else if (is_Filter(node)) { /* filter */
90 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
91 ir_node * pred = get_irn_n(node, i);
92 if (is_Unknown(pred) || is_Bad(pred)) {
93 irg_walk_cg(pred, visited, irg_set, pre, post, env);
96 exec = skip_Proj(get_Block_cfgpred(get_nodes_block(node), i));
102 assert(is_CallBegin(exec) ||
103 get_irn_op(exec) == op_EndReg ||
104 get_irn_op(exec) == op_EndExcept);
105 if (pset_new_contains(irg_set, get_irn_irg(exec))) {
106 current_ir_graph = get_irn_irg(exec);
107 irg_walk_cg(pred, visited, irg_set, pre, post, env);
108 current_ir_graph = rem;
112 } else { /* everything else */
113 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
114 irg_walk_cg(get_irn_n(node, i), visited, irg_set, pre, post, env);
118 if (post) post(node, env);
120 current_ir_graph = rem;
124 * Insert all ir_graphs in irg_set, that are (transitive) reachable.
126 static void collect_irgs(ir_node * node, pset_new_t *irg_set)
130 for (i = get_Call_n_callees(node) - 1; i >= 0; --i) {
131 ir_entity * ent = get_Call_callee(node, i);
132 ir_graph * irg = get_entity_irg(ent);
133 if (irg && !pset_new_contains(irg_set, irg)) {
134 pset_new_insert(irg_set, irg);
135 irg_walk_graph(irg, (irg_walk_func *) collect_irgs, NULL, irg_set);
143 * specialized version of irg_walk_2, called if only pre callback exists
145 * @return number of visited nodes
147 static unsigned irg_walk_2_pre(ir_node *node, irg_walk_func *pre, void *env)
151 ir_graph *irg = get_irn_irg(node);
153 set_irn_visited(node, irg->visited);
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);
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);
171 * specialized version of irg_walk_2, called if only post callback exists
173 * @return number of visited nodes
175 static unsigned irg_walk_2_post(ir_node *node, irg_walk_func *post, void *env)
179 ir_graph *irg = get_irn_irg(node);
181 set_irn_visited(node, irg->visited);
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);
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);
200 * specialized version of irg_walk_2, called if pre and post callbacks exist
202 * @return number of visited nodes
204 static unsigned irg_walk_2_both(ir_node *node, irg_walk_func *pre,
205 irg_walk_func *post, void *env)
209 ir_graph *irg = get_irn_irg(node);
211 set_irn_visited(node, irg->visited);
215 if (node->op != op_Block) {
216 ir_node *pred = get_irn_n(node, -1);
217 if (pred->visited < irg->visited)
218 cnt += irg_walk_2_both(pred, pre, post, env);
220 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
221 ir_node *pred = get_irn_n(node, i);
222 if (pred->visited < irg->visited)
223 cnt += irg_walk_2_both(pred, pre, post, env);
232 * Intraprozedural graph walker.
234 * @return number of visited nodes
236 unsigned irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
239 if (irn_visited(node))
242 if (!post) return irg_walk_2_pre (node, pre, env);
243 else if (!pre) return irg_walk_2_post(node, post, env);
244 else return irg_walk_2_both(node, pre, post, env);
248 static unsigned nodes_touched = 0;
250 void irg_walk_core(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
253 assert(is_ir_node(node));
255 #ifdef INTERPROCEDURAL_VIEW
256 if (get_interprocedural_view()) {
258 pset_new_iterator_t iter;
259 ir_visited_t visited;
261 assert(get_irp_ip_view_state() == ip_view_valid);
263 pset_new_init(&irg_set);
264 set_interprocedural_view(0);
265 pset_new_insert(&irg_set, current_ir_graph);
266 irg_walk(node, (irg_walk_func *) collect_irgs, NULL, &irg_set);
267 set_interprocedural_view(1);
268 visited = get_max_irg_visited() + 1;
270 foreach_pset_new(&irg_set, irg, iter) {
271 set_irg_visited(irg, visited);
273 irg_walk_cg(node, visited, &irg_set, pre, post, env);
274 pset_new_destroy(&irg_set);
277 nodes_touched = irg_walk_2(node, pre, post, env);
278 #ifdef INTERPROCEDURAL_VIEW
283 void irg_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
286 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
287 inc_irg_visited(current_ir_graph);
288 assert(current_ir_graph == get_irn_irg(node));
289 irg_walk_core(node, pre, post, env);
290 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
296 void irg_walk_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
298 ir_graph * rem = current_ir_graph;
300 hook_irg_walk(irg, (generic_func *)pre, (generic_func *)post);
301 current_ir_graph = irg;
302 irg_walk(get_irg_end(irg), pre, post, env);
303 irg->estimated_node_count = nodes_touched;
304 current_ir_graph = rem;
307 /* Executes irg_walk(end, pre, post, env) for all irgraphs in irprog.
308 Sets current_ir_graph properly for each walk. Conserves current
310 void all_irg_walk(irg_walk_func *pre, irg_walk_func *post, void *env)
315 for (i = 0, n = get_irp_n_irgs(); i < n; i++) {
316 irg = get_irp_irg(i);
317 irg_walk_graph(irg, pre, post, env);
321 /***************************************************************************/
324 * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
326 * @return number of visited nodes
328 static unsigned irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env)
332 ir_graph *irg = get_irn_irg(node);
334 set_irn_visited(node, irg->visited);
338 if (node->op != op_Block) {
339 ir_node *pred = get_irn_n(node, -1);
340 if (pred->visited < irg->visited)
341 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
343 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
344 ir_node *pred = get_irn_in_or_dep(node, i);
345 if (pred->visited < irg->visited)
346 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
352 * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
354 * @return number of visited nodes
356 static unsigned irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env)
360 ir_graph *irg = get_irn_irg(node);
362 set_irn_visited(node, irg->visited);
364 if (node->op != op_Block) {
365 ir_node *pred = get_irn_n(node, -1);
366 if (pred->visited < irg->visited)
367 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
369 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
370 ir_node *pred = get_irn_in_or_dep(node, i);
371 if (pred->visited < irg->visited)
372 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
381 * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
383 * @return number of visited nodes
385 static unsigned irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
389 ir_graph *irg = get_irn_irg(node);
391 set_irn_visited(node, irg->visited);
395 if (node->op != op_Block) {
396 ir_node *pred = get_irn_n(node, -1);
397 if (pred->visited < irg->visited)
398 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
400 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
401 ir_node *pred = get_irn_in_or_dep(node, i);
402 if (pred->visited < irg->visited)
403 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
412 * Intraprozedural graph walker. Follows dependency edges as well.
414 * @return number of visited nodes
416 static unsigned irg_walk_in_or_dep_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
418 if (irn_visited(node))
421 if (! post) return irg_walk_in_or_dep_2_pre (node, pre, env);
422 else if (! pre) return irg_walk_in_or_dep_2_post(node, post, env);
423 else return irg_walk_in_or_dep_2_both(node, pre, post, env);
427 * Generic graph walker. Follows dependency edges as well.
429 void irg_walk_in_or_dep(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
431 assert(is_ir_node(node));
433 #ifdef INTERPROCEDURAL_VIEW
434 if (get_interprocedural_view()) {
435 panic("This is not yet implemented.");
438 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
439 inc_irg_visited(current_ir_graph);
440 nodes_touched = irg_walk_in_or_dep_2(node, pre, post, env);
441 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
445 * Walk over a graph. Follow all edges (including dependencies)
447 void irg_walk_in_or_dep_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
449 ir_graph * rem = current_ir_graph;
451 hook_irg_walk(irg, (generic_func *)pre, (generic_func *)post);
452 current_ir_graph = irg;
453 irg_walk_in_or_dep(get_irg_end(irg), pre, post, env);
454 irg->estimated_node_count = nodes_touched;
455 current_ir_graph = rem;
458 /***************************************************************************/
460 #ifdef INTERPROCEDURAL_VIEW
462 * Returns current_ir_graph and sets it to the irg of predecessor index
465 static inline ir_graph * switch_irg(ir_node *n, int index)
467 ir_graph *old_current = current_ir_graph;
469 if (get_interprocedural_view()) {
470 /* Only Filter and Block nodes can have predecessors in other graphs. */
472 n = get_nodes_block(n);
474 ir_node *cfop = skip_Proj(get_Block_cfgpred(n, index));
475 if (is_ip_cfop(cfop)) {
476 current_ir_graph = get_irn_irg(cfop);
484 static void cg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
487 ir_graph *rem = NULL;
490 if (get_irn_visited(node) < get_irg_visited(current_ir_graph)) {
491 set_irn_visited(node, get_irg_visited(current_ir_graph));
493 if (pre) pre(node, env);
495 if (is_no_Block(node))
496 cg_walk_2(get_nodes_block(node), pre, post, env);
497 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
498 rem = switch_irg(node, i); /* @@@ AS: Is this wrong? We do have to
499 switch to the irg of the predecessor, don't we? */
500 cg_walk_2(get_irn_n(node, i), pre, post, env);
501 current_ir_graph = rem;
504 if (post) post(node, env);
508 /* Walks all irgs in interprocedural view. Visits each node only once. */
509 void cg_walk(irg_walk_func *pre, irg_walk_func *post, void *env)
512 ir_graph *rem = current_ir_graph;
513 int rem_view = get_interprocedural_view();
515 set_interprocedural_view(1);
517 inc_max_irg_visited();
518 /* Fix all irg_visited flags */
519 for (i = 0; i < get_irp_n_irgs(); i++)
520 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
522 /* Walk starting at unreachable procedures. Only these
523 * have End blocks visible in interprocedural view. */
524 for (i = 0; i < get_irp_n_irgs(); i++) {
526 current_ir_graph = get_irp_irg(i);
528 sb = get_irg_start_block(current_ir_graph);
530 if ((get_Block_n_cfgpreds(sb) > 1) ||
531 (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
533 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
536 /* Check whether we walked all procedures: there could be procedures
537 with cyclic calls but no call from the outside. */
538 for (i = 0; i < get_irp_n_irgs(); i++) {
540 current_ir_graph = get_irp_irg(i);
542 /* Test start block: if inner procedure end and end block are not
543 * visible and therefore not marked. */
544 sb = get_irg_start_block(current_ir_graph);
545 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
546 cg_walk_2(sb, pre, post, env);
550 /* Walk all endless loops in inner procedures.
551 * We recognize an inner procedure if the End node is not visited. */
552 for (i = 0; i < get_irp_n_irgs(); i++) {
554 current_ir_graph = get_irp_irg(i);
555 e = get_irg_end(current_ir_graph);
556 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
558 /* Don't visit the End node. */
559 for (j = 0; j < get_End_n_keepalives(e); j++)
560 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
564 set_interprocedural_view(rem_view);
565 current_ir_graph = rem;
570 /***************************************************************************/
572 /* Walks back from n until it finds a real cf op. */
573 static ir_node *get_cf_op(ir_node *n)
575 while (!is_cfop(n) && !is_fragile_op(n) && !is_Bad(n)) {
583 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre,
584 irg_walk_func *post, void *env)
588 if (Block_block_visited(node))
590 mark_Block_block_visited(node);
595 for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
596 /* find the corresponding predecessor block. */
597 ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
598 pred = get_nodes_block(pred);
599 if (get_irn_opcode(pred) == iro_Block) {
601 irg_block_walk_2(pred, pre, post, env);
603 assert(get_irn_opcode(pred) == iro_Bad);
612 /* walks only over Block nodes in the graph. Has it's own visited
613 flag, so that it can be interleaved with the other walker. */
614 void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
616 ir_graph *irg = get_irn_irg(node);
617 ir_node *block, *pred;
620 hook_irg_block_walk(irg, node, (generic_func *)pre, (generic_func *)post);
623 #ifdef INTERPROCEDURAL_VIEW
624 assert(!get_interprocedural_view()); /* interprocedural_view not implemented, because it
625 * interleaves with irg_walk */
627 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
628 inc_irg_block_visited(irg);
629 block = is_Block(node) ? node : get_nodes_block(node);
630 assert(is_Block(block));
631 irg_block_walk_2(block, pre, post, env);
633 /* keepalive: the endless loops ... */
635 int arity = get_irn_arity(node);
636 for (i = 0; i < arity; i++) {
637 pred = get_irn_n(node, i);
638 if (!is_Block(pred)) {
639 pred = get_nodes_block(pred);
640 if (!is_Block(pred)) {
641 /* if rare cases a kept node might have a bad block input */
645 /* Sometimes the blocks died, but are still reachable through kept nodes.
646 * Make sure the algorithms that try to remove these reach them. */
647 irg_block_walk_2(pred, pre, post, env);
651 ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
655 * walk over a graph block wise
657 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
658 irg_walk_func *post, void *env)
660 ir_graph * rem = current_ir_graph;
661 current_ir_graph = irg;
662 irg_block_walk(get_irg_end(irg), pre, post, env);
663 current_ir_graph = rem;
667 * Additionally walk over all anchors. Do NOT increase the visit flag.
669 void irg_walk_anchors(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
671 ir_graph * rem = current_ir_graph;
672 current_ir_graph = irg;
674 inc_irg_visited(irg);
675 irg_walk_2(irg->anchor, pre, post, env);
677 current_ir_graph = rem;
680 /********************************************************************/
682 typedef struct walk_env {
688 static void walk_initializer(ir_initializer_t *initializer, walk_env *env)
690 switch (initializer->kind) {
691 case IR_INITIALIZER_CONST:
692 irg_walk(initializer->consti.value, env->pre, env->post, env->env);
694 case IR_INITIALIZER_TARVAL:
695 case IR_INITIALIZER_NULL:
698 case IR_INITIALIZER_COMPOUND: {
700 for (i = 0; i < initializer->compound.n_initializers; ++i) {
701 ir_initializer_t *subinitializer
702 = initializer->compound.initializers[i];
703 walk_initializer(subinitializer, env);
708 panic("invalid initializer found");
712 * Walk to all constant expressions in this entity.
714 static void walk_entity(ir_entity *ent, void *env)
716 walk_env *my_env = (walk_env *)env;
718 if (ent->initializer != NULL) {
719 walk_initializer(ent->initializer, my_env);
720 } else if (entity_has_compound_ent_values(ent)) {
721 int i, n_vals = get_compound_ent_n_values(ent);
723 for (i = 0; i < n_vals; i++)
724 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
728 /* Walks over all code in const_code_irg. */
729 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env)
735 ir_graph *rem = current_ir_graph;
736 current_ir_graph = get_const_code_irg();
737 inc_irg_visited(current_ir_graph);
743 /* Walk all types that can contain constant entities. */
744 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; s++)
745 walk_types_entities(get_segment_type(s), &walk_entity, &my_env);
746 n_types = get_irp_n_types();
747 for (i = 0; i < n_types; i++)
748 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
749 for (i = 0; i < get_irp_n_irgs(); i++)
750 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
752 /* Walk constant array bounds. */
753 for (i = 0; i < n_types; i++) {
754 ir_type *tp = get_irp_type(i);
755 if (is_Array_type(tp)) {
756 int n_dim = get_array_n_dimensions(tp);
757 for (j = 0; j < n_dim; j++) {
758 ir_node *n = get_array_lower_bound(tp, j);
759 if (n) irg_walk(n, pre, post, env);
760 n = get_array_upper_bound(tp, j);
761 if (n) irg_walk(n, pre, post, env);
766 current_ir_graph = rem;