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
148 irg_walk_2_pre(ir_node *node, irg_walk_func *pre, void * env)
152 ir_graph *irg = current_ir_graph;
154 set_irn_visited(node, irg->visited);
158 if (node->op != op_Block) {
159 ir_node *pred = get_irn_n(node, -1);
160 if (pred->visited < irg->visited)
161 cnt += irg_walk_2_pre(pred, pre, env);
163 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
164 ir_node *pred = get_irn_n(node, i);
165 if (pred->visited < irg->visited)
166 cnt += irg_walk_2_pre(pred, pre, env);
172 * specialized version of irg_walk_2, called if only post callback exists
174 * @return number of visited nodes
177 irg_walk_2_post(ir_node *node, irg_walk_func *post, void * env)
181 ir_graph *irg = current_ir_graph;
183 set_irn_visited(node, irg->visited);
185 if (node->op != op_Block) {
186 ir_node *pred = get_irn_n(node, -1);
187 if (pred->visited < irg->visited)
188 cnt += irg_walk_2_post(pred, post, env);
190 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
191 ir_node *pred = get_irn_n(node, i);
192 if (pred->visited < irg->visited)
193 cnt += irg_walk_2_post(pred, post, env);
202 * specialized version of irg_walk_2, called if pre and post callbacks exist
204 * @return number of visited nodes
207 irg_walk_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
211 ir_graph *irg = current_ir_graph;
213 set_irn_visited(node, irg->visited);
217 if (node->op != op_Block) {
218 ir_node *pred = get_irn_n(node, -1);
219 if (pred->visited < irg->visited)
220 cnt += irg_walk_2_both(pred, pre, post, env);
222 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
223 ir_node *pred = get_irn_n(node, i);
224 if (pred->visited < irg->visited)
225 cnt += irg_walk_2_both(pred, pre, post, env);
234 * Intraprozedural graph walker.
236 * @return number of visited nodes
238 unsigned irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
241 if (node->visited < current_ir_graph->visited) {
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);
250 static unsigned nodes_touched = 0;
253 * generic graph walker
255 void irg_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
257 assert(is_ir_node(node));
259 #ifdef INTERPROCEDURAL_VIEW
260 if (get_interprocedural_view()) {
262 pset_new_iterator_t iter;
263 ir_visited_t visited;
265 assert(get_irp_ip_view_state() == ip_view_valid);
267 pset_new_init(&irg_set);
268 set_interprocedural_view(0);
269 pset_new_insert(&irg_set, current_ir_graph);
270 irg_walk(node, (irg_walk_func *) collect_irgs, NULL, &irg_set);
271 set_interprocedural_view(1);
272 visited = get_max_irg_visited() + 1;
274 foreach_pset_new(&irg_set, irg, iter) {
275 set_irg_visited(irg, visited);
277 irg_walk_cg(node, visited, &irg_set, pre, post, env);
278 pset_new_destroy(&irg_set);
281 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
282 inc_irg_visited(current_ir_graph);
283 nodes_touched = irg_walk_2(node, pre, post, env);
284 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
285 #ifdef INTERPROCEDURAL_VIEW
293 void irg_walk_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
295 ir_graph * rem = current_ir_graph;
297 hook_irg_walk(irg, (generic_func *)pre, (generic_func *)post);
298 current_ir_graph = irg;
299 irg_walk(get_irg_end(irg), pre, post, env);
300 irg->estimated_node_count = nodes_touched;
301 current_ir_graph = rem;
304 /* Executes irg_walk(end, pre, post, env) for all irgraphs in irprog.
305 Sets current_ir_graph properly for each walk. Conserves current
307 void all_irg_walk(irg_walk_func *pre, irg_walk_func *post, void *env)
312 for (i = 0, n = get_irp_n_irgs(); i < n; i++) {
313 irg = get_irp_irg(i);
314 irg_walk_graph(irg, pre, post, env);
318 /***************************************************************************/
321 * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
323 * @return number of visited nodes
326 irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env)
330 ir_graph *irg = current_ir_graph;
332 set_irn_visited(node, irg->visited);
336 if (node->op != op_Block) {
337 ir_node *pred = get_irn_n(node, -1);
338 if (pred->visited < irg->visited)
339 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
341 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
342 ir_node *pred = get_irn_in_or_dep(node, i);
343 if (pred->visited < irg->visited)
344 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
350 * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
352 * @return number of visited nodes
355 irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env)
359 ir_graph *irg = current_ir_graph;
361 set_irn_visited(node, irg->visited);
363 if (node->op != op_Block) {
364 ir_node *pred = get_irn_n(node, -1);
365 if (pred->visited < irg->visited)
366 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
368 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
369 ir_node *pred = get_irn_in_or_dep(node, i);
370 if (pred->visited < irg->visited)
371 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
380 * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
382 * @return number of visited nodes
385 irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
389 ir_graph *irg = current_ir_graph;
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
417 irg_walk_in_or_dep_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
419 if (node->visited < current_ir_graph->visited) {
420 if (! post) return irg_walk_in_or_dep_2_pre (node, pre, env);
421 else if (! pre) return irg_walk_in_or_dep_2_post(node, post, env);
422 else return irg_walk_in_or_dep_2_both(node, pre, post, env);
428 * Generic graph walker. Follows dependency edges as well.
430 void irg_walk_in_or_dep(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
432 assert(is_ir_node(node));
434 if (get_interprocedural_view()) {
435 assert(0 && "This is not yet implemented.");
437 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
438 inc_irg_visited(current_ir_graph);
439 nodes_touched = irg_walk_in_or_dep_2(node, pre, post, env);
440 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 /***************************************************************************/
461 * Returns current_ir_graph and sets it to the irg of predecessor index
464 static inline ir_graph *
465 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 #ifdef INTERPROCEDURAL_VIEW
486 cg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
489 ir_graph *rem = NULL;
492 if (get_irn_visited(node) < get_irg_visited(current_ir_graph)) {
493 set_irn_visited(node, get_irg_visited(current_ir_graph));
495 if (pre) pre(node, env);
497 if (is_no_Block(node))
498 cg_walk_2(get_nodes_block(node), pre, post, env);
499 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
500 rem = switch_irg(node, i); /* @@@ AS: Is this wrong? We do have to
501 switch to the irg of the predecessor, don't we? */
502 cg_walk_2(get_irn_n(node, i), pre, post, env);
503 current_ir_graph = rem;
506 if (post) post(node, env);
510 /* Walks all irgs in interprocedural view. Visits each node only once. */
511 void cg_walk(irg_walk_func *pre, irg_walk_func *post, void *env)
514 ir_graph *rem = current_ir_graph;
515 int rem_view = get_interprocedural_view();
517 set_interprocedural_view(1);
519 inc_max_irg_visited();
520 /* Fix all irg_visited flags */
521 for (i = 0; i < get_irp_n_irgs(); i++)
522 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
524 /* Walk starting at unreachable procedures. Only these
525 * have End blocks visible in interprocedural view. */
526 for (i = 0; i < get_irp_n_irgs(); i++) {
528 current_ir_graph = get_irp_irg(i);
530 sb = get_irg_start_block(current_ir_graph);
532 if ((get_Block_n_cfgpreds(sb) > 1) ||
533 (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
535 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
538 /* Check whether we walked all procedures: there could be procedures
539 with cyclic calls but no call from the outside. */
540 for (i = 0; i < get_irp_n_irgs(); i++) {
542 current_ir_graph = get_irp_irg(i);
544 /* Test start block: if inner procedure end and end block are not
545 * visible and therefore not marked. */
546 sb = get_irg_start_block(current_ir_graph);
547 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
548 cg_walk_2(sb, pre, post, env);
552 /* Walk all endless loops in inner procedures.
553 * We recognize an inner procedure if the End node is not visited. */
554 for (i = 0; i < get_irp_n_irgs(); i++) {
556 current_ir_graph = get_irp_irg(i);
557 e = get_irg_end(current_ir_graph);
558 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
560 /* Don't visit the End node. */
561 for (j = 0; j < get_End_n_keepalives(e); j++)
562 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
566 set_interprocedural_view(rem_view);
567 current_ir_graph = rem;
572 /***************************************************************************/
574 /* Walks back from n until it finds a real cf op. */
575 static ir_node *get_cf_op(ir_node *n)
577 while (!is_cfop(n) && !is_fragile_op(n) && !is_Bad(n)) {
585 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
589 if (!Block_block_visited(node)) {
590 mark_Block_block_visited(node);
592 if (pre) pre(node, env);
594 for(i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
595 /* find the corresponding predecessor block. */
596 ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
597 pred = get_nodes_block(pred);
598 if (get_irn_opcode(pred) == iro_Block) {
600 irg_block_walk_2(pred, pre, post, env);
603 assert(get_irn_opcode(pred) == iro_Bad);
607 if (post) post(node, env);
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 = current_ir_graph;
617 ir_node *block, *pred;
620 hook_irg_block_walk(irg, node, (generic_func *)pre, (generic_func *)post);
623 assert(!get_interprocedural_view()); /* interprocedural_view not implemented, because it
624 * interleaves with irg_walk */
625 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
626 inc_irg_block_visited(irg);
627 block = is_Block(node) ? node : get_nodes_block(node);
628 assert(is_Block(block));
629 irg_block_walk_2(block, pre, post, env);
631 /* keepalive: the endless loops ... */
633 int arity = get_irn_arity(node);
634 for (i = 0; i < arity; i++) {
635 pred = get_irn_n(node, i);
636 if (!is_Block(pred)) {
637 pred = get_nodes_block(pred);
638 if (!is_Block(pred)) {
639 /* if rare cases a kept node might have a bad block input */
643 /* Sometimes the blocks died, but are still reachable through kept nodes.
644 * Make sure the algorithms that try to remove these reach them. */
645 irg_block_walk_2(pred, pre, post, env);
649 ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
653 * walk over a graph block wise
655 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
656 irg_walk_func *post, void *env) {
657 ir_graph * rem = current_ir_graph;
658 current_ir_graph = irg;
659 irg_block_walk(get_irg_end(irg), pre, post, env);
660 current_ir_graph = rem;
664 * Additionally walk over all anchors. Do NOT increase the visit flag.
666 void irg_walk_anchors(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
668 ir_graph * rem = current_ir_graph;
669 current_ir_graph = irg;
671 inc_irg_visited(irg);
672 irg_walk_2(irg->anchor, pre, post, env);
674 current_ir_graph = rem;
677 /********************************************************************/
679 typedef struct walk_env {
685 static void walk_initializer(ir_initializer_t *initializer, walk_env *env)
687 switch(initializer->kind) {
688 case IR_INITIALIZER_CONST:
689 irg_walk(initializer->consti.value, env->pre, env->post, env->env);
691 case IR_INITIALIZER_TARVAL:
692 case IR_INITIALIZER_NULL:
695 case IR_INITIALIZER_COMPOUND: {
697 for(i = 0; i < initializer->compound.n_initializers; ++i) {
698 ir_initializer_t *subinitializer
699 = initializer->compound.initializers[i];
700 walk_initializer(subinitializer, env);
705 panic("invalid initializer found");
709 * Walk to all constant expressions in this entity.
711 static void walk_entity(ir_entity *ent, void *env)
713 walk_env *my_env = (walk_env *)env;
715 if (ent->initializer != NULL) {
716 walk_initializer(ent->initializer, my_env);
717 } else if (entity_has_compound_ent_values(ent)) {
718 int i, n_vals = get_compound_ent_n_values(ent);
720 for (i = 0; i < n_vals; i++)
721 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
725 /* Walks over all code in const_code_irg. */
726 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env)
732 ir_graph *rem = current_ir_graph;
733 current_ir_graph = get_const_code_irg();
734 inc_irg_visited(current_ir_graph);
740 /* Walk all types that can contain constant entities. */
741 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; s++)
742 walk_types_entities(get_segment_type(s), &walk_entity, &my_env);
743 n_types = get_irp_n_types();
744 for (i = 0; i < n_types; i++)
745 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
746 for (i = 0; i < get_irp_n_irgs(); i++)
747 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
749 /* Walk constant array bounds. */
750 for (i = 0; i < n_types; i++) {
751 ir_type *tp = get_irp_type(i);
752 if (is_Array_type(tp)) {
753 int n_dim = get_array_n_dimensions(tp);
754 for (j = 0; j < n_dim; j++) {
755 ir_node *n = get_array_lower_bound(tp, j);
756 if (n) irg_walk(n, pre, post, env);
757 n = get_array_upper_bound(tp, j);
758 if (n) irg_walk(n, pre, post, env);
763 current_ir_graph = rem;