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 = current_ir_graph;
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 = current_ir_graph;
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, irg_walk_func *post, void * env)
208 ir_graph *irg = current_ir_graph;
210 set_irn_visited(node, irg->visited);
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);
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);
231 * Intraprozedural graph walker.
233 * @return number of visited nodes
235 unsigned irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
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);
247 static unsigned nodes_touched = 0;
250 * generic graph walker
252 void irg_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
254 assert(is_ir_node(node));
256 #ifdef INTERPROCEDURAL_VIEW
257 if (get_interprocedural_view()) {
259 pset_new_iterator_t iter;
260 ir_visited_t visited;
262 assert(get_irp_ip_view_state() == ip_view_valid);
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;
271 foreach_pset_new(&irg_set, irg, iter) {
272 set_irg_visited(irg, visited);
274 irg_walk_cg(node, visited, &irg_set, pre, post, env);
275 pset_new_destroy(&irg_set);
278 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
279 inc_irg_visited(current_ir_graph);
280 nodes_touched = irg_walk_2(node, pre, post, env);
281 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
282 #ifdef INTERPROCEDURAL_VIEW
290 void irg_walk_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
292 ir_graph * rem = current_ir_graph;
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;
301 /* Executes irg_walk(end, pre, post, env) for all irgraphs in irprog.
302 Sets current_ir_graph properly for each walk. Conserves current
304 void all_irg_walk(irg_walk_func *pre, irg_walk_func *post, void *env)
309 for (i = 0, n = get_irp_n_irgs(); i < n; i++) {
310 irg = get_irp_irg(i);
311 irg_walk_graph(irg, pre, post, env);
315 /***************************************************************************/
318 * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
320 * @return number of visited nodes
322 static unsigned irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env)
326 ir_graph *irg = current_ir_graph;
328 set_irn_visited(node, irg->visited);
332 if (node->op != op_Block) {
333 ir_node *pred = get_irn_n(node, -1);
334 if (pred->visited < irg->visited)
335 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
337 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
338 ir_node *pred = get_irn_in_or_dep(node, i);
339 if (pred->visited < irg->visited)
340 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
346 * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
348 * @return number of visited nodes
350 static unsigned irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env)
354 ir_graph *irg = current_ir_graph;
356 set_irn_visited(node, irg->visited);
358 if (node->op != op_Block) {
359 ir_node *pred = get_irn_n(node, -1);
360 if (pred->visited < irg->visited)
361 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
363 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
364 ir_node *pred = get_irn_in_or_dep(node, i);
365 if (pred->visited < irg->visited)
366 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
375 * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
377 * @return number of visited nodes
379 static unsigned irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
383 ir_graph *irg = current_ir_graph;
385 set_irn_visited(node, irg->visited);
389 if (node->op != op_Block) {
390 ir_node *pred = get_irn_n(node, -1);
391 if (pred->visited < irg->visited)
392 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
394 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
395 ir_node *pred = get_irn_in_or_dep(node, i);
396 if (pred->visited < irg->visited)
397 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
406 * Intraprozedural graph walker. Follows dependency edges as well.
408 * @return number of visited nodes
410 static unsigned irg_walk_in_or_dep_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
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);
421 * Generic graph walker. Follows dependency edges as well.
423 void irg_walk_in_or_dep(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
425 assert(is_ir_node(node));
427 if (get_interprocedural_view()) {
428 assert(0 && "This is not yet implemented.");
430 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
431 inc_irg_visited(current_ir_graph);
432 nodes_touched = irg_walk_in_or_dep_2(node, pre, post, env);
433 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
438 * Walk over a graph. Follow all edges (including dependencies)
440 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;
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;
451 /***************************************************************************/
454 * Returns current_ir_graph and sets it to the irg of predecessor index
457 static inline ir_graph * switch_irg(ir_node *n, int index)
459 ir_graph *old_current = current_ir_graph;
461 if (get_interprocedural_view()) {
462 /* Only Filter and Block nodes can have predecessors in other graphs. */
464 n = get_nodes_block(n);
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);
476 #ifdef INTERPROCEDURAL_VIEW
477 static void cg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
480 ir_graph *rem = NULL;
483 if (get_irn_visited(node) < get_irg_visited(current_ir_graph)) {
484 set_irn_visited(node, get_irg_visited(current_ir_graph));
486 if (pre) pre(node, env);
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;
497 if (post) post(node, env);
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)
505 ir_graph *rem = current_ir_graph;
506 int rem_view = get_interprocedural_view();
508 set_interprocedural_view(1);
510 inc_max_irg_visited();
511 /* Fix all irg_visited flags */
512 for (i = 0; i < get_irp_n_irgs(); i++)
513 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
515 /* Walk starting at unreachable procedures. Only these
516 * have End blocks visible in interprocedural view. */
517 for (i = 0; i < get_irp_n_irgs(); i++) {
519 current_ir_graph = get_irp_irg(i);
521 sb = get_irg_start_block(current_ir_graph);
523 if ((get_Block_n_cfgpreds(sb) > 1) ||
524 (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
526 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
529 /* Check whether we walked all procedures: there could be procedures
530 with cyclic calls but no call from the outside. */
531 for (i = 0; i < get_irp_n_irgs(); i++) {
533 current_ir_graph = get_irp_irg(i);
535 /* Test start block: if inner procedure end and end block are not
536 * visible and therefore not marked. */
537 sb = get_irg_start_block(current_ir_graph);
538 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
539 cg_walk_2(sb, pre, post, env);
543 /* Walk all endless loops in inner procedures.
544 * We recognize an inner procedure if the End node is not visited. */
545 for (i = 0; i < get_irp_n_irgs(); i++) {
547 current_ir_graph = get_irp_irg(i);
548 e = get_irg_end(current_ir_graph);
549 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
551 /* Don't visit the End node. */
552 for (j = 0; j < get_End_n_keepalives(e); j++)
553 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
557 set_interprocedural_view(rem_view);
558 current_ir_graph = rem;
563 /***************************************************************************/
565 /* Walks back from n until it finds a real cf op. */
566 static ir_node *get_cf_op(ir_node *n)
568 while (!is_cfop(n) && !is_fragile_op(n) && !is_Bad(n)) {
576 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
580 if (!Block_block_visited(node)) {
581 mark_Block_block_visited(node);
583 if (pre) pre(node, env);
585 for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
586 /* find the corresponding predecessor block. */
587 ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
588 pred = get_nodes_block(pred);
589 if (get_irn_opcode(pred) == iro_Block) {
591 irg_block_walk_2(pred, pre, post, env);
594 assert(get_irn_opcode(pred) == iro_Bad);
598 if (post) post(node, env);
603 /* walks only over Block nodes in the graph. Has it's own visited
604 flag, so that it can be interleaved with the other walker. */
605 void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
607 ir_graph *irg = current_ir_graph;
608 ir_node *block, *pred;
611 hook_irg_block_walk(irg, node, (generic_func *)pre, (generic_func *)post);
614 assert(!get_interprocedural_view()); /* interprocedural_view not implemented, because it
615 * interleaves with irg_walk */
616 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
617 inc_irg_block_visited(irg);
618 block = is_Block(node) ? node : get_nodes_block(node);
619 assert(is_Block(block));
620 irg_block_walk_2(block, pre, post, env);
622 /* keepalive: the endless loops ... */
624 int arity = get_irn_arity(node);
625 for (i = 0; i < arity; i++) {
626 pred = get_irn_n(node, i);
627 if (!is_Block(pred)) {
628 pred = get_nodes_block(pred);
629 if (!is_Block(pred)) {
630 /* if rare cases a kept node might have a bad block input */
634 /* Sometimes the blocks died, but are still reachable through kept nodes.
635 * Make sure the algorithms that try to remove these reach them. */
636 irg_block_walk_2(pred, pre, post, env);
640 ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
644 * walk over a graph block wise
646 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
647 irg_walk_func *post, void *env)
649 ir_graph * rem = current_ir_graph;
650 current_ir_graph = irg;
651 irg_block_walk(get_irg_end(irg), pre, post, env);
652 current_ir_graph = rem;
656 * Additionally walk over all anchors. Do NOT increase the visit flag.
658 void irg_walk_anchors(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
660 ir_graph * rem = current_ir_graph;
661 current_ir_graph = irg;
663 inc_irg_visited(irg);
664 irg_walk_2(irg->anchor, pre, post, env);
666 current_ir_graph = rem;
669 /********************************************************************/
671 typedef struct walk_env {
677 static void walk_initializer(ir_initializer_t *initializer, walk_env *env)
679 switch (initializer->kind) {
680 case IR_INITIALIZER_CONST:
681 irg_walk(initializer->consti.value, env->pre, env->post, env->env);
683 case IR_INITIALIZER_TARVAL:
684 case IR_INITIALIZER_NULL:
687 case IR_INITIALIZER_COMPOUND: {
689 for (i = 0; i < initializer->compound.n_initializers; ++i) {
690 ir_initializer_t *subinitializer
691 = initializer->compound.initializers[i];
692 walk_initializer(subinitializer, env);
697 panic("invalid initializer found");
701 * Walk to all constant expressions in this entity.
703 static void walk_entity(ir_entity *ent, void *env)
705 walk_env *my_env = (walk_env *)env;
707 if (ent->initializer != NULL) {
708 walk_initializer(ent->initializer, my_env);
709 } else if (entity_has_compound_ent_values(ent)) {
710 int i, n_vals = get_compound_ent_n_values(ent);
712 for (i = 0; i < n_vals; i++)
713 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
717 /* Walks over all code in const_code_irg. */
718 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env)
724 ir_graph *rem = current_ir_graph;
725 current_ir_graph = get_const_code_irg();
726 inc_irg_visited(current_ir_graph);
732 /* Walk all types that can contain constant entities. */
733 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; s++)
734 walk_types_entities(get_segment_type(s), &walk_entity, &my_env);
735 n_types = get_irp_n_types();
736 for (i = 0; i < n_types; i++)
737 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
738 for (i = 0; i < get_irp_n_irgs(); i++)
739 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
741 /* Walk constant array bounds. */
742 for (i = 0; i < n_types; i++) {
743 ir_type *tp = get_irp_type(i);
744 if (is_Array_type(tp)) {
745 int n_dim = get_array_n_dimensions(tp);
746 for (j = 0; j < n_dim; j++) {
747 ir_node *n = get_array_lower_bound(tp, j);
748 if (n) irg_walk(n, pre, post, env);
749 n = get_array_upper_bound(tp, j);
750 if (n) irg_walk(n, pre, post, env);
755 current_ir_graph = rem;