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) {
129 for (i = get_Call_n_callees(node) - 1; i >= 0; --i) {
130 ir_entity * ent = get_Call_callee(node, i);
131 ir_graph * irg = get_entity_irg(ent);
132 if (irg && !pset_new_contains(irg_set, irg)) {
133 pset_new_insert(irg_set, irg);
134 irg_walk_graph(irg, (irg_walk_func *) collect_irgs, NULL, irg_set);
142 * specialized version of irg_walk_2, called if only pre callback exists
144 * @return number of visited nodes
147 irg_walk_2_pre(ir_node *node, irg_walk_func *pre, void * env) {
150 ir_graph *irg = current_ir_graph;
152 set_irn_visited(node, irg->visited);
156 if (node->op != op_Block) {
157 ir_node *pred = get_irn_n(node, -1);
158 if (pred->visited < irg->visited)
159 cnt += irg_walk_2_pre(pred, pre, env);
161 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
162 ir_node *pred = get_irn_n(node, i);
163 if (pred->visited < irg->visited)
164 cnt += irg_walk_2_pre(pred, pre, env);
170 * specialized version of irg_walk_2, called if only post callback exists
172 * @return number of visited nodes
175 irg_walk_2_post(ir_node *node, irg_walk_func *post, void * env) {
178 ir_graph *irg = current_ir_graph;
180 set_irn_visited(node, irg->visited);
182 if (node->op != op_Block) {
183 ir_node *pred = get_irn_n(node, -1);
184 if (pred->visited < irg->visited)
185 cnt += irg_walk_2_post(pred, post, env);
187 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
188 ir_node *pred = get_irn_n(node, i);
189 if (pred->visited < irg->visited)
190 cnt += irg_walk_2_post(pred, post, env);
199 * specialized version of irg_walk_2, called if pre and post callbacks exist
201 * @return number of visited nodes
204 irg_walk_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env) {
207 ir_graph *irg = current_ir_graph;
209 set_irn_visited(node, irg->visited);
213 if (node->op != op_Block) {
214 ir_node *pred = get_irn_n(node, -1);
215 if (pred->visited < irg->visited)
216 cnt += irg_walk_2_both(pred, pre, post, env);
218 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
219 ir_node *pred = get_irn_n(node, i);
220 if (pred->visited < irg->visited)
221 cnt += irg_walk_2_both(pred, pre, post, env);
230 * Intraprozedural graph walker.
232 * @return number of visited nodes
235 irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
237 if (node->visited < current_ir_graph->visited) {
238 if (!post) return irg_walk_2_pre (node, pre, env);
239 else if (!pre) return irg_walk_2_post(node, post, env);
240 else return irg_walk_2_both(node, pre, post, env);
246 static unsigned nodes_touched = 0;
249 * generic graph walker
251 void irg_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
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 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
278 inc_irg_visited(current_ir_graph);
279 nodes_touched = irg_walk_2(node, pre, post, env);
280 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
281 #ifdef INTERPROCEDURAL_VIEW
289 void irg_walk_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
290 ir_graph * rem = current_ir_graph;
292 hook_irg_walk(irg, (generic_func *)pre, (generic_func *)post);
293 current_ir_graph = irg;
294 irg_walk(get_irg_end(irg), pre, post, env);
295 irg->estimated_node_count = nodes_touched;
296 current_ir_graph = rem;
299 /* Executes irg_walk(end, pre, post, env) for all irgraphs in irprog.
300 Sets current_ir_graph properly for each walk. Conserves current
302 void all_irg_walk(irg_walk_func *pre, irg_walk_func *post, void *env) {
306 for (i = 0, n = get_irp_n_irgs(); i < n; i++) {
307 irg = get_irp_irg(i);
308 irg_walk_graph(irg, pre, post, env);
312 /***************************************************************************/
315 * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
317 * @return number of visited nodes
320 irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env) {
323 ir_graph *irg = current_ir_graph;
325 set_irn_visited(node, irg->visited);
329 if (node->op != op_Block) {
330 ir_node *pred = get_irn_n(node, -1);
331 if (pred->visited < irg->visited)
332 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
334 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
335 ir_node *pred = get_irn_in_or_dep(node, i);
336 if (pred->visited < irg->visited)
337 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
343 * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
345 * @return number of visited nodes
348 irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env) {
351 ir_graph *irg = current_ir_graph;
353 set_irn_visited(node, irg->visited);
355 if (node->op != op_Block) {
356 ir_node *pred = get_irn_n(node, -1);
357 if (pred->visited < irg->visited)
358 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
360 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
361 ir_node *pred = get_irn_in_or_dep(node, i);
362 if (pred->visited < irg->visited)
363 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
372 * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
374 * @return number of visited nodes
377 irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env) {
380 ir_graph *irg = current_ir_graph;
382 set_irn_visited(node, irg->visited);
386 if (node->op != op_Block) {
387 ir_node *pred = get_irn_n(node, -1);
388 if (pred->visited < irg->visited)
389 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
391 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
392 ir_node *pred = get_irn_in_or_dep(node, i);
393 if (pred->visited < irg->visited)
394 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
403 * Intraprozedural graph walker. Follows dependency edges as well.
405 * @return number of visited nodes
408 irg_walk_in_or_dep_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
410 if (node->visited < current_ir_graph->visited) {
411 if (! post) return irg_walk_in_or_dep_2_pre (node, pre, env);
412 else if (! pre) return irg_walk_in_or_dep_2_post(node, post, env);
413 else return irg_walk_in_or_dep_2_both(node, pre, post, env);
419 * Generic graph walker. Follows dependency edges as well.
421 void irg_walk_in_or_dep(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
423 assert(is_ir_node(node));
425 if (get_interprocedural_view()) {
426 assert(0 && "This is not yet implemented.");
428 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
429 inc_irg_visited(current_ir_graph);
430 nodes_touched = irg_walk_in_or_dep_2(node, pre, post, env);
431 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
436 * Walk over a graph. Follow all edges (including dependencies)
438 void irg_walk_in_or_dep_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
439 ir_graph * rem = current_ir_graph;
441 hook_irg_walk(irg, (generic_func *)pre, (generic_func *)post);
442 current_ir_graph = irg;
443 irg_walk_in_or_dep(get_irg_end(irg), pre, post, env);
444 irg->estimated_node_count = nodes_touched;
445 current_ir_graph = rem;
448 /***************************************************************************/
451 * Returns current_ir_graph and sets it to the irg of predecessor index
454 static inline ir_graph *
455 switch_irg(ir_node *n, int index) {
456 ir_graph *old_current = current_ir_graph;
458 if (get_interprocedural_view()) {
459 /* Only Filter and Block nodes can have predecessors in other graphs. */
461 n = get_nodes_block(n);
463 ir_node *cfop = skip_Proj(get_Block_cfgpred(n, index));
464 if (is_ip_cfop(cfop)) {
465 current_ir_graph = get_irn_irg(cfop);
473 #ifdef INTERPROCEDURAL_VIEW
475 cg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
478 ir_graph *rem = NULL;
481 if (get_irn_visited(node) < get_irg_visited(current_ir_graph)) {
482 set_irn_visited(node, get_irg_visited(current_ir_graph));
484 if (pre) pre(node, env);
486 if (is_no_Block(node))
487 cg_walk_2(get_nodes_block(node), pre, post, env);
488 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
489 rem = switch_irg(node, i); /* @@@ AS: Is this wrong? We do have to
490 switch to the irg of the predecessor, don't we? */
491 cg_walk_2(get_irn_n(node, i), pre, post, env);
492 current_ir_graph = rem;
495 if (post) post(node, env);
499 /* Walks all irgs in interprocedural view. Visits each node only once. */
500 void cg_walk(irg_walk_func *pre, irg_walk_func *post, void *env) {
502 ir_graph *rem = current_ir_graph;
503 int rem_view = get_interprocedural_view();
505 set_interprocedural_view(1);
507 inc_max_irg_visited();
508 /* Fix all irg_visited flags */
509 for (i = 0; i < get_irp_n_irgs(); i++)
510 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
512 /* Walk starting at unreachable procedures. Only these
513 * have End blocks visible in interprocedural view. */
514 for (i = 0; i < get_irp_n_irgs(); i++) {
516 current_ir_graph = get_irp_irg(i);
518 sb = get_irg_start_block(current_ir_graph);
520 if ((get_Block_n_cfgpreds(sb) > 1) ||
521 (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
523 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
526 /* Check whether we walked all procedures: there could be procedures
527 with cyclic calls but no call from the outside. */
528 for (i = 0; i < get_irp_n_irgs(); i++) {
530 current_ir_graph = get_irp_irg(i);
532 /* Test start block: if inner procedure end and end block are not
533 * visible and therefore not marked. */
534 sb = get_irg_start_block(current_ir_graph);
535 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
536 cg_walk_2(sb, pre, post, env);
540 /* Walk all endless loops in inner procedures.
541 * We recognize an inner procedure if the End node is not visited. */
542 for (i = 0; i < get_irp_n_irgs(); i++) {
544 current_ir_graph = get_irp_irg(i);
545 e = get_irg_end(current_ir_graph);
546 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
548 /* Don't visit the End node. */
549 for (j = 0; j < get_End_n_keepalives(e); j++)
550 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
554 set_interprocedural_view(rem_view);
555 current_ir_graph = rem;
560 /***************************************************************************/
562 /* Walks back from n until it finds a real cf op. */
563 static ir_node *get_cf_op(ir_node *n) {
564 while (!is_cfop(n) && !is_fragile_op(n) && !is_Bad(n)) {
572 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
576 if (!Block_block_visited(node)) {
577 mark_Block_block_visited(node);
579 if (pre) pre(node, env);
581 for(i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
582 /* find the corresponding predecessor block. */
583 ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
584 pred = get_nodes_block(pred);
585 if (get_irn_opcode(pred) == iro_Block) {
587 irg_block_walk_2(pred, pre, post, env);
590 assert(get_irn_opcode(pred) == iro_Bad);
594 if (post) post(node, env);
599 /* walks only over Block nodes in the graph. Has it's own visited
600 flag, so that it can be interleaved with the other walker. */
601 void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
603 ir_graph *irg = current_ir_graph;
604 ir_node *block, *pred;
607 hook_irg_block_walk(irg, node, (generic_func *)pre, (generic_func *)post);
610 assert(!get_interprocedural_view()); /* interprocedural_view not implemented, because it
611 * interleaves with irg_walk */
612 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
613 inc_irg_block_visited(irg);
614 block = is_Block(node) ? node : get_nodes_block(node);
615 assert(is_Block(block));
616 irg_block_walk_2(block, pre, post, env);
618 /* keepalive: the endless loops ... */
620 int arity = get_irn_arity(node);
621 for (i = 0; i < arity; i++) {
622 pred = get_irn_n(node, i);
623 if (!is_Block(pred)) {
624 pred = get_nodes_block(pred);
625 if (!is_Block(pred)) {
626 /* if rare cases a kept node might have a bad block input */
630 /* Sometimes the blocks died, but are still reachable through kept nodes.
631 * Make sure the algorithms that try to remove these reach them. */
632 irg_block_walk_2(pred, pre, post, env);
636 ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
640 * walk over a graph block wise
642 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
643 irg_walk_func *post, void *env) {
644 ir_graph * rem = current_ir_graph;
645 current_ir_graph = irg;
646 irg_block_walk(get_irg_end(irg), pre, post, env);
647 current_ir_graph = rem;
651 * Additionally walk over all anchors. Do NOT increase the visit flag.
653 void irg_walk_anchors(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
654 ir_graph * rem = current_ir_graph;
655 current_ir_graph = irg;
657 inc_irg_visited(irg);
658 irg_walk_2(irg->anchor, pre, post, env);
660 current_ir_graph = rem;
663 /********************************************************************/
665 typedef struct walk_env {
671 static void walk_initializer(ir_initializer_t *initializer, walk_env *env)
673 switch(initializer->kind) {
674 case IR_INITIALIZER_CONST:
675 irg_walk(initializer->consti.value, env->pre, env->post, env->env);
677 case IR_INITIALIZER_TARVAL:
678 case IR_INITIALIZER_NULL:
681 case IR_INITIALIZER_COMPOUND: {
683 for(i = 0; i < initializer->compound.n_initializers; ++i) {
684 ir_initializer_t *subinitializer
685 = initializer->compound.initializers[i];
686 walk_initializer(subinitializer, env);
691 panic("invalid initializer found");
695 * Walk to all constant expressions in this entity.
697 static void walk_entity(ir_entity *ent, void *env)
699 walk_env *my_env = (walk_env *)env;
701 if (get_entity_variability(ent) != variability_uninitialized) {
702 if (ent->has_initializer) {
703 walk_initializer(ent->attr.initializer, my_env);
704 } else if (is_atomic_entity(ent)) {
705 irg_walk(get_atomic_ent_value(ent), my_env->pre, my_env->post, my_env->env);
707 int i, n_vals = get_compound_ent_n_values(ent);
709 for (i = 0; i < n_vals; i++)
710 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
715 /* Walks over all code in const_code_irg. */
716 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env) {
720 ir_graph *rem = current_ir_graph;
721 current_ir_graph = get_const_code_irg();
722 inc_irg_visited(current_ir_graph);
728 /* Walk all types that can contain constant entities. */
729 for (i = 0; i < IR_SEGMENT_COUNT; i++)
730 walk_types_entities(get_segment_type((ir_segment_t) i), &walk_entity, &my_env);
731 n_types = get_irp_n_types();
732 for (i = 0; i < n_types; i++)
733 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
734 for (i = 0; i < get_irp_n_irgs(); i++)
735 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
737 /* Walk constant array bounds. */
738 for (i = 0; i < n_types; i++) {
739 ir_type *tp = get_irp_type(i);
740 if (is_Array_type(tp)) {
741 int n_dim = get_array_n_dimensions(tp);
742 for (j = 0; j < n_dim; j++) {
743 ir_node *n = get_array_lower_bound(tp, j);
744 if (n) irg_walk(n, pre, post, env);
745 n = get_array_upper_bound(tp, j);
746 if (n) irg_walk(n, pre, post, env);
751 current_ir_graph = rem;