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
39 #include "irgraph_t.h"
51 * Walk over an interprocedural graph (callgraph).
52 * Visits only graphs in irg_set.
54 static void irg_walk_cg(ir_node * node, unsigned long visited,
55 pset_new_t *irg_set, irg_walk_func *pre,
56 irg_walk_func *post, void * env) {
58 ir_graph * rem = current_ir_graph;
61 assert(node && node->kind == k_ir_node);
62 if (get_irn_visited(node) >= visited) return;
64 set_irn_visited(node, visited);
66 if (pre) pre(node, env);
68 pred = skip_Proj(node);
69 if (get_irn_op(pred) == op_CallBegin
70 || get_irn_op(pred) == op_EndReg
71 || get_irn_op(pred) == op_EndExcept) {
72 current_ir_graph = get_irn_irg(pred);
75 if (is_no_Block(node)) { /* not block */
76 irg_walk_cg(get_nodes_block(node), visited, irg_set, pre, post, env);
79 if (get_irn_op(node) == op_Block) { /* block */
80 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
81 ir_node * exec = get_irn_n(node, i);
82 ir_node * pred = skip_Proj(exec);
83 if ((get_irn_op(pred) != op_CallBegin
84 && get_irn_op(pred) != op_EndReg
85 && get_irn_op(pred) != op_EndExcept)
86 || pset_new_contains(irg_set, get_irn_irg(pred))) {
87 irg_walk_cg(exec, visited, irg_set, pre, post, env);
90 } else if (get_irn_op(node) == op_Filter) { /* filter */
91 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
92 ir_node * pred = get_irn_n(node, i);
93 if (get_irn_op(pred) == op_Unknown || get_irn_op(pred) == op_Bad) {
94 irg_walk_cg(pred, visited, irg_set, pre, post, env);
97 exec = skip_Proj(get_Block_cfgpred(get_nodes_block(node), i));
99 if (op_Bad == get_irn_op (exec)) {
103 assert(get_irn_op(exec) == op_CallBegin
104 || get_irn_op(exec) == op_EndReg
105 || get_irn_op(exec) == op_EndExcept);
106 if (pset_new_contains(irg_set, get_irn_irg(exec))) {
107 current_ir_graph = get_irn_irg(exec);
108 irg_walk_cg(pred, visited, irg_set, pre, post, env);
109 current_ir_graph = rem;
113 } else { /* everything else */
114 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
115 irg_walk_cg(get_irn_n(node, i), visited, irg_set, pre, post, env);
119 if (post) post(node, env);
121 current_ir_graph = rem;
126 * Insert all ir_graphs in irg_set, that are (transitive) reachable.
128 static void collect_irgs(ir_node * node, pset_new_t *irg_set) {
131 for (i = get_Call_n_callees(node) - 1; i >= 0; --i) {
132 ir_entity * ent = get_Call_callee(node, i);
133 ir_graph * irg = get_entity_irg(ent);
134 if (irg && !pset_new_contains(irg_set, irg)) {
135 pset_new_insert(irg_set, irg);
136 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) {
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
176 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
205 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
236 irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
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 unsigned long 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 set_using_irn_visited(current_ir_graph);
279 inc_irg_visited(current_ir_graph);
280 nodes_touched = irg_walk_2(node, pre, post, env);
281 clear_using_irn_visited(current_ir_graph);
282 #ifdef INTERPROCEDURAL_VIEW
291 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) {
308 for (i = 0, n = get_irp_n_irgs(); i < n; i++) {
309 irg = get_irp_irg(i);
310 irg_walk_graph(irg, pre, post, env);
314 /***************************************************************************/
317 * specialized version of irg_walk_in_or_dep_2, called if only pre callback exists
319 * @return number of visited nodes
322 irg_walk_in_or_dep_2_pre(ir_node *node, irg_walk_func *pre, void *env) {
325 ir_graph *irg = current_ir_graph;
327 set_irn_visited(node, irg->visited);
331 if (node->op != op_Block) {
332 ir_node *pred = get_irn_n(node, -1);
333 if (pred->visited < irg->visited)
334 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
336 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
337 ir_node *pred = get_irn_in_or_dep(node, i);
338 if (pred->visited < irg->visited)
339 cnt += irg_walk_in_or_dep_2_pre(pred, pre, env);
345 * specialized version of irg_walk_in_or_dep_2, called if only post callback exists
347 * @return number of visited nodes
350 irg_walk_in_or_dep_2_post(ir_node *node, irg_walk_func *post, void *env) {
353 ir_graph *irg = current_ir_graph;
355 set_irn_visited(node, irg->visited);
357 if (node->op != op_Block) {
358 ir_node *pred = get_irn_n(node, -1);
359 if (pred->visited < irg->visited)
360 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
362 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
363 ir_node *pred = get_irn_in_or_dep(node, i);
364 if (pred->visited < irg->visited)
365 cnt += irg_walk_in_or_dep_2_post(pred, post, env);
374 * specialized version of irg_walk_in_or_dep_2, called if pre and post callbacks exist
376 * @return number of visited nodes
379 irg_walk_in_or_dep_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env) {
382 ir_graph *irg = current_ir_graph;
384 set_irn_visited(node, irg->visited);
388 if (node->op != op_Block) {
389 ir_node *pred = get_irn_n(node, -1);
390 if (pred->visited < irg->visited)
391 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
393 for (i = get_irn_ins_or_deps(node) - 1; i >= 0; --i) {
394 ir_node *pred = get_irn_in_or_dep(node, i);
395 if (pred->visited < irg->visited)
396 cnt += irg_walk_in_or_dep_2_both(pred, pre, post, env);
405 * Intraprozedural graph walker. Follows dependency edges as well.
407 * @return number of visited nodes
410 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 set_using_irn_visited(current_ir_graph);
431 inc_irg_visited(current_ir_graph);
432 nodes_touched = irg_walk_in_or_dep_2(node, pre, post, env);
433 clear_using_irn_visited(current_ir_graph);
439 * Walk over a graph. Follow all edges (including dependencies)
441 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 *
458 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. */
463 if (get_irn_op(n) == op_Filter)
464 n = get_nodes_block(n);
465 if (get_irn_op(n) == op_Block) {
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);
477 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);
502 #ifdef INTERPROCEDURAL_VIEW
503 /* Walks all irgs in interprocedural view. Visits each node only once. */
504 void cg_walk(irg_walk_func *pre, irg_walk_func *post, void *env) {
506 ir_graph *rem = current_ir_graph;
507 int rem_view = get_interprocedural_view();
509 set_interprocedural_view(1);
511 inc_max_irg_visited();
512 /* Fix all irg_visited flags */
513 for (i = 0; i < get_irp_n_irgs(); i++)
514 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
516 /* Walk starting at unreachable procedures. Only these
517 * have End blocks visible in interprocedural view. */
518 for (i = 0; i < get_irp_n_irgs(); i++) {
520 current_ir_graph = get_irp_irg(i);
522 sb = get_irg_start_block(current_ir_graph);
524 if ((get_Block_n_cfgpreds(sb) > 1) ||
525 (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
527 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
530 /* Check whether we walked all procedures: there could be procedures
531 with cyclic calls but no call from the outside. */
532 for (i = 0; i < get_irp_n_irgs(); i++) {
534 current_ir_graph = get_irp_irg(i);
536 /* Test start block: if inner procedure end and end block are not
537 * visible and therefore not marked. */
538 sb = get_irg_start_block(current_ir_graph);
539 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
540 cg_walk_2(sb, pre, post, env);
544 /* Walk all endless loops in inner procedures.
545 * We recognize an inner procedure if the End node is not visited. */
546 for (i = 0; i < get_irp_n_irgs(); i++) {
548 current_ir_graph = get_irp_irg(i);
549 e = get_irg_end(current_ir_graph);
550 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
552 /* Don't visit the End node. */
553 for (j = 0; j < get_End_n_keepalives(e); j++)
554 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
558 set_interprocedural_view(rem_view);
559 current_ir_graph = rem;
564 /***************************************************************************/
566 /* Walks back from n until it finds a real cf op. */
567 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_not_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_node *block, *pred;
610 hook_irg_block_walk(current_ir_graph, node, (generic_func *)pre, (generic_func *)post);
613 assert(!get_interprocedural_view()); /* interprocedural_view not implemented, because it
614 * interleaves with irg_walk */
615 set_using_block_visited(current_ir_graph);
616 inc_irg_block_visited(current_ir_graph);
617 block = is_Block(node) ? node : get_nodes_block(node);
618 assert(get_irn_op(block) == op_Block);
619 irg_block_walk_2(block, pre, post, env);
621 /* keepalive: the endless loops ... */
622 if (get_irn_op(node) == op_End) {
623 int arity = get_irn_arity(node);
624 for (i = 0; i < arity; i++) {
625 pred = get_irn_n(node, i);
626 if (get_irn_op(pred) == op_Block)
627 irg_block_walk_2(pred, pre, post, env);
629 /* Sometimes the blocks died, but are still reachable through Phis.
630 * Make sure the algorithms that try to remove these reach them. */
631 for (i = 0; i < arity; i++) {
632 pred = get_irn_n(node, i);
633 if (get_irn_op(pred) == op_Phi) {
634 ir_node *block = get_nodes_block(pred);
637 irg_block_walk_2(block, pre, post, env);
642 clear_using_block_visited(current_ir_graph);
646 * walk over a graph block wise
648 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
649 irg_walk_func *post, void *env) {
650 ir_graph * rem = current_ir_graph;
651 current_ir_graph = irg;
652 irg_block_walk(get_irg_end(irg), pre, post, env);
653 current_ir_graph = rem;
657 * Additionally walk over all anchors. Do NOT increase the visit flag.
659 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 (get_entity_variability(ent) != variability_uninitialized) {
708 if (ent->has_initializer) {
709 walk_initializer(ent->attr.initializer, my_env);
710 } else if (is_atomic_entity(ent)) {
711 irg_walk(get_atomic_ent_value(ent), my_env->pre, my_env->post, my_env->env);
713 int i, n_vals = get_compound_ent_n_values(ent);
715 for (i = 0; i < n_vals; i++)
716 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
721 /* Walks over all code in const_code_irg. */
722 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env) {
726 ir_graph *rem = current_ir_graph;
727 current_ir_graph = get_const_code_irg();
728 inc_irg_visited(current_ir_graph);
734 /* Walk all types that can contain constant entities. */
735 walk_types_entities(get_glob_type(), &walk_entity, &my_env);
736 n_types = get_irp_n_types();
737 for (i = 0; i < n_types; i++)
738 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
739 for (i = 0; i < get_irp_n_irgs(); i++)
740 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
742 /* Walk constant array bounds. */
743 for (i = 0; i < n_types; i++) {
744 ir_type *tp = get_irp_type(i);
745 if (is_Array_type(tp)) {
746 int n_dim = get_array_n_dimensions(tp);
747 for (j = 0; j < n_dim; j++) {
748 ir_node *n = get_array_lower_bound(tp, j);
749 if (n) irg_walk(n, pre, post, env);
750 n = get_array_upper_bound(tp, j);
751 if (n) irg_walk(n, pre, post, env);
756 current_ir_graph = rem;