3 * File name: ir/ir/irgwalk.c
5 * Author: Boris Boesler
6 * Modified by: Goetz Lindenmaier
9 * Copyright: (c) 1999-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
14 * traverse an ir graph
15 * - execute the pre function before recursion
16 * - execute the post function after recursion
27 #include "irgraph_t.h" /* visited flag */
37 /* walk over an interprocedural graph (callgraph). Visits only graphs in irg_set. */
38 static void irg_walk_cg(ir_node * node, int visited, eset * irg_set,
39 irg_walk_func *pre, irg_walk_func *post, void * env) {
41 ir_graph * rem = current_ir_graph;
44 assert(node && node->kind == k_ir_node);
45 if (get_irn_visited(node) >= visited) return;
47 set_irn_visited(node, visited);
49 if (pre) pre(node, env);
51 pred = skip_Proj(node);
52 if (get_irn_op(pred) == op_CallBegin
53 || get_irn_op(pred) == op_EndReg
54 || get_irn_op(pred) == op_EndExcept) {
55 current_ir_graph = get_irn_irg(pred);
58 if (is_no_Block(node)) { /* not block */
59 irg_walk_cg(get_nodes_block(node), visited, irg_set, pre, post, env);
62 if (get_irn_op(node) == op_Block) { /* block */
63 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
64 ir_node * exec = get_irn_n(node, i);
65 ir_node * pred = skip_Proj(exec);
66 if ((get_irn_op(pred) != op_CallBegin
67 && get_irn_op(pred) != op_EndReg
68 && get_irn_op(pred) != op_EndExcept)
69 || eset_contains(irg_set, get_irn_irg(pred))) {
70 irg_walk_cg(exec, visited, irg_set, pre, post, env);
73 } else if (get_irn_op(node) == op_Filter) { /* filter */
74 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
75 ir_node * pred = get_irn_n(node, i);
76 if (get_irn_op(pred) == op_Unknown || get_irn_op(pred) == op_Bad) {
77 irg_walk_cg(pred, visited, irg_set, pre, post, env);
80 exec = skip_Proj(get_Block_cfgpred(get_nodes_block(node), i));
82 if (op_Bad == get_irn_op (exec)) {
86 assert(get_irn_op(exec) == op_CallBegin
87 || get_irn_op(exec) == op_EndReg
88 || get_irn_op(exec) == op_EndExcept);
89 if (eset_contains(irg_set, get_irn_irg(exec))) {
90 current_ir_graph = get_irn_irg(exec);
91 irg_walk_cg(pred, visited, irg_set, pre, post, env);
92 current_ir_graph = rem;
96 } else { /* everything else */
97 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
98 irg_walk_cg(get_irn_n(node, i), visited, irg_set, pre, post, env);
102 if (post) post(node, env);
104 current_ir_graph = rem;
108 /* Insert all ir_graphs in irg_set, that are (transitive) reachable. */
109 static void collect_irgs(ir_node * node, eset * irg_set) {
110 if (get_irn_op(node) == op_Call) {
112 for (i = get_Call_n_callees(node) - 1; i >= 0; --i) {
113 entity * ent = get_Call_callee(node, i);
114 ir_graph * irg = ent ? get_entity_irg(ent) : NULL;
115 if (irg && !eset_contains(irg_set, irg)) {
116 eset_insert(irg_set, irg);
117 irg_walk_graph(irg, (irg_walk_func *) collect_irgs, NULL, irg_set);
124 * specialized version of irg_walk_2, called if only pre callback exists
127 irg_walk_2_pre(ir_node *node, irg_walk_func *pre, void * env) {
129 set_irn_visited(node, current_ir_graph->visited);
133 if (node->op != op_Block) {
134 ir_node *pred = get_irn_n(node, -1);
135 if (pred->visited < current_ir_graph->visited)
136 irg_walk_2_pre(pred, pre, env);
138 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
139 ir_node *pred = get_irn_n(node, i);
140 if (pred->visited < current_ir_graph->visited)
141 irg_walk_2_pre(pred, pre, env);
146 * specialized version of irg_walk_2, called if only post callback exists
149 irg_walk_2_post(ir_node *node, irg_walk_func *post, void * env) {
151 set_irn_visited(node, current_ir_graph->visited);
153 if (node->op != op_Block) {
154 ir_node *pred = get_irn_n(node, -1);
155 if (pred->visited < current_ir_graph->visited)
156 irg_walk_2_post(pred, post, env);
158 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
159 ir_node *pred = get_irn_n(node, i);
160 if (pred->visited < current_ir_graph->visited)
161 irg_walk_2_post(pred, post, env);
168 * specialized version of irg_walk_2, called if pre and post callbacks exist
171 irg_walk_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env) {
173 set_irn_visited(node, current_ir_graph->visited);
177 if (node->op != op_Block) {
178 ir_node *pred = get_irn_n(node, -1);
179 if (pred->visited < current_ir_graph->visited)
180 irg_walk_2_both(pred, pre, post, env);
182 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
183 ir_node *pred = get_irn_n(node, i);
184 if (pred->visited < current_ir_graph->visited)
185 irg_walk_2_both(pred, pre, post, env);
192 * Intraprozedural graph walker.
195 irg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
197 if (node->visited < current_ir_graph->visited) {
198 if (!post) irg_walk_2_pre (node, pre, env);
199 else if (!pre) irg_walk_2_post(node, post, env);
200 else irg_walk_2_both(node, pre, post, env);
205 * generic graph walker
207 void irg_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
209 assert(node && node->kind==k_ir_node);
211 if (interprocedural_view) {
212 eset * irg_set = eset_create();
215 assert(get_irp_ip_view_state() == ip_view_valid);
217 interprocedural_view = false;
218 eset_insert(irg_set, current_ir_graph);
219 irg_walk(node, (irg_walk_func *) collect_irgs, NULL, irg_set);
220 interprocedural_view = true;
221 visited = get_max_irg_visited() + 1;
222 for (irg = eset_first(irg_set); irg; irg = eset_next(irg_set)) {
223 set_irg_visited(irg, visited);
225 irg_walk_cg(node, visited, irg_set, pre, post, env);
226 eset_destroy(irg_set);
228 inc_irg_visited(current_ir_graph);
229 irg_walk_2(node, pre, post, env);
235 void irg_walk_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env) {
236 ir_graph * rem = current_ir_graph;
238 stat_irg_walk(irg, (void *)pre, (void *)post);
239 current_ir_graph = irg;
240 irg_walk(get_irg_end(irg), pre, post, env);
241 current_ir_graph = rem;
244 /* Executes irg_walk(end, pre, post, env) for all irgraphs in irprog.
245 Sets current_ir_graph properly for each walk. Conserves current
247 void all_irg_walk(irg_walk_func *pre, irg_walk_func *post, void *env) {
251 rem = current_ir_graph;
253 for (i = 0; i < get_irp_n_irgs(); i++) {
254 irg = get_irp_irg(i);
255 current_ir_graph = irg;
256 irg_walk(get_irg_end(irg), pre, post, env);
258 current_ir_graph = rem;
261 /***************************************************************************/
263 /* Returns current_ir_graph and sets it to the irg of predecessor index
265 static INLINE ir_graph *
266 switch_irg (ir_node *n, int index) {
267 ir_graph *old_current = current_ir_graph;
269 if (interprocedural_view) {
270 /* Only Filter and Block nodes can have predecessors in other graphs. */
271 if (get_irn_op(n) == op_Filter)
272 n = get_nodes_block(n);
273 if (get_irn_op(n) == op_Block) {
274 ir_node *cfop = skip_Proj(get_Block_cfgpred(n, index));
275 if (is_ip_cfop(cfop)) {
276 current_ir_graph = get_irn_irg(cfop);
285 cg_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env)
288 ir_graph *rem = NULL;
291 if (get_irn_visited(node) < get_irg_visited(current_ir_graph)) {
292 set_irn_visited(node, get_irg_visited(current_ir_graph));
294 if (pre) pre(node, env);
296 if (is_no_Block(node))
297 cg_walk_2(get_nodes_block(node), pre, post, env);
298 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
299 rem = switch_irg(node, i); /* @@@ AS: Is this wrong? We do have to
300 switch to the irg of the predecessor, don't we? */
301 cg_walk_2(get_irn_n(node, i), pre, post, env);
302 current_ir_graph = rem;
305 if (post) post(node, env);
311 /* Walks all irgs in interprocedural view. Visits each node only once. */
312 void cg_walk(irg_walk_func *pre, irg_walk_func *post, void *env) {
314 ir_graph *rem = current_ir_graph;
315 int rem_view = interprocedural_view;
317 interprocedural_view = true;
319 inc_max_irg_visited();
320 /* Fix all irg_visited flags */
321 for (i = 0; i < get_irp_n_irgs(); i++)
322 set_irg_visited(get_irp_irg(i), get_max_irg_visited());
324 /* Walk starting at unreachable procedures. Only these
325 * have End blocks visible in interprocedural view. */
326 for (i = 0; i < get_irp_n_irgs(); i++) {
328 current_ir_graph = get_irp_irg(i);
330 sb = get_irg_start_block(current_ir_graph);
332 if ((get_Block_n_cfgpreds(sb) > 1) ||
333 (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
335 cg_walk_2(get_irg_end(current_ir_graph), pre, post, env);
338 /* Check whether we walked all procedures: there could be procedures
339 with cyclic calls but no call from the outside. */
340 for (i = 0; i < get_irp_n_irgs(); i++) {
342 current_ir_graph = get_irp_irg(i);
344 /* Test start block: if inner procedure end and end block are not
345 * visible and therefore not marked. */
346 sb = get_irg_start_block(current_ir_graph);
347 if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) {
348 cg_walk_2(sb, pre, post, env);
352 /* Walk all endless loops in inner procedures.
353 * We recognize an inner procedure if the End node is not visited. */
354 for (i = 0; i < get_irp_n_irgs(); i++) {
356 current_ir_graph = get_irp_irg(i);
357 e = get_irg_end(current_ir_graph);
358 if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
360 /* Don't visit the End node. */
361 for (j = 0; j < get_End_n_keepalives(e); j++)
362 cg_walk_2(get_End_keepalive(e, j), pre, post, env);
366 interprocedural_view = rem_view;
367 current_ir_graph = rem;
371 /***************************************************************************/
373 /* Walks back from n until it finds a real cf op. */
374 static ir_node *get_cf_op(ir_node *n) {
380 if (!(is_cfop(pred) || is_fragile_op(pred) ||
381 (get_irn_op(pred) == op_Bad)))
387 static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
391 if(get_Block_block_visited(node) < get_irg_block_visited(current_ir_graph)) {
392 set_Block_block_visited(node, get_irg_block_visited(current_ir_graph));
394 if(pre) pre(node, env);
396 for(i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
397 /* find the corresponding predecessor block. */
398 ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
399 pred = get_nodes_block(pred);
400 if(get_irn_opcode(pred) == iro_Block) {
402 irg_block_walk_2(pred, pre, post, env);
405 assert(get_irn_opcode(pred) == iro_Bad);
409 if(post) post(node, env);
415 /* walks only over Block nodes in the graph. Has it's own visited
416 flag, so that it can be interleaved with the other walker. */
417 void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void *env)
419 ir_node *block, *pred;
422 stat_irg_block_walk(current_ir_graph, node, (void *)pre, (void *)post);
425 assert(!interprocedural_view); /* interprocedural_view not implemented, because it
426 * interleaves with irg_walk */
427 inc_irg_block_visited(current_ir_graph);
428 if (is_no_Block(node)) block = get_nodes_block(node); else block = node;
429 assert(get_irn_opcode(block) == iro_Block);
430 irg_block_walk_2(block, pre, post, env);
431 /* keepalive: the endless loops ... */
432 if (get_irn_op(node) == op_End) {
433 int arity = get_irn_arity(node);
434 for (i = 0; i < arity; i++) {
435 pred = get_irn_n(node, i);
436 if (get_irn_op(pred) == op_Block)
437 irg_block_walk_2(pred, pre, post, env);
445 void irg_block_walk_graph(ir_graph *irg, irg_walk_func *pre,
446 irg_walk_func *post, void *env) {
447 ir_graph * rem = current_ir_graph;
448 current_ir_graph = irg;
449 irg_block_walk(get_irg_end(irg), pre, post, env);
450 current_ir_graph = rem;
453 /********************************************************************/
455 typedef struct walk_env {
461 /* Walk to all constant expressions in this entity. */
462 static void walk_entity(entity *ent, void *env)
464 walk_env *my_env = (walk_env *)env;
466 if (get_entity_variability(ent) != variability_uninitialized) {
467 if (is_atomic_entity(ent)) {
468 irg_walk(get_atomic_ent_value(ent), my_env->pre, my_env->post, my_env->env);
471 int i, n = get_compound_ent_n_values(ent);
473 for (i = 0; i < n; i++)
474 irg_walk(get_compound_ent_value(ent, i), my_env->pre, my_env->post, my_env->env);
479 /* Walks over all code in const_code_irg. */
480 void walk_const_code(irg_walk_func *pre, irg_walk_func *post, void *env) {
484 ir_graph *rem = current_ir_graph;
485 current_ir_graph = get_const_code_irg();
486 inc_irg_visited(current_ir_graph);
492 /* Walk all types that can contain constant entities. */
493 walk_types_entities(get_glob_type(), &walk_entity, &my_env);
494 for (i = 0; i < get_irp_n_types(); i++)
495 walk_types_entities(get_irp_type(i), &walk_entity, &my_env);
496 for (i = 0; i < get_irp_n_irgs(); i++)
497 walk_types_entities(get_irg_frame_type(get_irp_irg(i)), &walk_entity, &my_env);
499 /* Walk constant array bounds. */
500 for (i = 0; i < get_irp_n_types(); i++) {
501 type *tp = get_irp_type(i);
502 if (is_array_type(tp)) {
503 for (j = 0; j < get_array_n_dimensions(tp); j++) {
505 n = get_array_lower_bound(tp, j);
506 if (n) irg_walk(n, pre, post, env);
507 n = get_array_upper_bound(tp, j);
508 if (n) irg_walk(n, pre, post, env);
513 current_ir_graph = rem;
517 /********************************************************************/
518 /** Walking support for interprocedural analysis **/
520 /** @@@ Don't use, not operational yet, doesn't grok recursions!! **/
521 /** @@@ Header for irgwalk.h, here until it works. **/
523 /** Interprocedural walking should not walk all predecessors of **/
524 /** all nodes. When leaving a procedure the walker should only **/
525 /** follow the edge corresponding to the most recent entry of the **/
526 /** procedure. The following functions use an internal stack to **/
527 /** remember the current call site of a procedure. **/
528 /** They also set current_ir_graph correctly. **/
530 /** Usage example: **/
532 /** void init_ip_walk (); **/
533 /** work_on_graph(some_end_node); **/
534 /** void finish_ip_walk(); **/
536 /** work_on_graph(ir_node *n) { **/
537 /** for (i = 0; i < get_irn_arity(n); i++) { **/
538 /** if (...) continue; **/
539 /** ir_node *m = get_irn_ip_pred(n, i); **/
540 /** if !m continue; **/
541 /** work_on_graph(m); **/
542 /** return_recur(n, i); **/
545 /********************************************************************/
547 /* Call for i in {0|-1 ... get_irn_arity(n)}.
548 If n is a conventional node returns the same node as get_irn_n(n, i).
549 If the predecessors of n are in the callee of the procedure n belongs
550 to, returns get_irn_n(n, i) if this node is in the callee on the top
551 of the stack, else returns NULL.
552 If the predecessors of n are in a procedure called by the procedure n
553 belongs to pushes the caller on the caller stack in the callee.
554 Sets current_ir_graph to the graph the node returned is in. */
555 ir_node *get_irn_ip_pred(ir_node *n, int pos);
557 /* If get_irn_ip_pred() returned a node (not NULL) this must be
558 called to clear up the stacks.
559 Sets current_ir_graph to the graph n is in. */
560 void return_recur(ir_node *n, int pos);
563 /********************************************************************/
564 /** Walking support for interprocedural analysis **/
565 /********************************************************************/
567 #define MIN_STACK_SIZE 40
569 typedef struct callsite_stack {
574 /* Access the stack in the irg **************************************/
577 set_irg_callsite_stack(ir_graph *g, callsite_stack *s) {
581 static INLINE callsite_stack *
582 get_irg_callsite_stack(ir_graph *g) {
583 return (callsite_stack *) get_irg_link(g);
586 /* A stack of callsites *********************************************/
588 /* @@@ eventually change the implementation so the new_ only sets the field
589 to NULL, and the stack is only allocated if used. Saves Memory! */
590 static INLINE callsite_stack *
591 new_callsite_stack(ir_graph *g) {
592 callsite_stack *res = (callsite_stack *)malloc(sizeof(callsite_stack));
594 res->s = NEW_ARR_F (ir_node *, MIN_STACK_SIZE);
595 set_irg_callsite_stack(g, res);
600 free_callsite_stack(ir_graph *g) {
601 callsite_stack *s = get_irg_callsite_stack(g);
607 push_callsite(ir_graph *callee, ir_node *callsite) {
608 callsite_stack *s = get_irg_callsite_stack(callee);
609 if (s->tos == ARR_LEN(s->s)) {
610 int nlen = ARR_LEN (s->s) * 2;
611 ARR_RESIZE (ir_node *, s->s, nlen);
613 s->s[s->tos] = callsite;
617 static INLINE ir_node *
618 get_top_of_callsite_stack(ir_graph *callee) {
619 callsite_stack *s = get_irg_callsite_stack(callee);
620 return (s->s[s->tos-1]);
624 ir_node * pop_callsite(ir_graph *callee) {
625 callsite_stack *s = get_irg_callsite_stack(callee);
627 return (s->s[s->tos]);
631 /* Initialization routines ******************************************/
633 void init_ip_walk (void) {
635 for (i = 0; i < get_irp_n_irgs(); i++)
636 new_callsite_stack(get_irp_irg(i));
639 void finish_ip_walk(void) {
641 for (i = 0; i < get_irp_n_irgs(); i++)
642 free_callsite_stack(get_irp_irg(i));
643 set_irg_link(get_irp_irg(i), NULL);
646 /* walker routines **************************************************/
648 /* cf_pred is End* */
650 enter_procedure(ir_node *block, ir_node *cf_pred, int pos) {
652 ir_graph *irg = get_irn_irg(cf_pred);
654 assert(interprocedural_view);
656 interprocedural_view = 0;
657 callbegin = skip_Proj(get_irn_n(block, 0));
658 assert(get_irn_op(callbegin) == op_CallBegin);
659 interprocedural_view = 1;
661 push_callsite(irg, callbegin);
662 current_ir_graph = irg;
665 /* cf_pred is CallBegin */
667 leave_procedure(ir_node *block, ir_node *cf_pred, int pos) {
668 ir_node *tos = get_top_of_callsite_stack(current_ir_graph);
670 assert(get_irn_op(cf_pred) == op_CallBegin);
672 if (tos == cf_pred) {
673 /* We entered this procedure by the call pred pos refers to. */
674 pop_callsite(current_ir_graph);
675 current_ir_graph = get_CallBegin_irg(cf_pred);
683 ir_node *get_irn_ip_pred(ir_node *n, int pos) {
685 if (interprocedural_view) {
687 /* Find the cf_pred refering to pos. */
690 if (get_irn_opcode(n) == iro_Filter) block = get_nodes_block(n);
691 cf_pred = skip_Proj(get_irn_n(block, pos));
693 /* Check whether we enter or leave a procedure and act according. */
694 if ((get_irn_op(cf_pred) == op_EndReg) ||
695 (get_irn_op(cf_pred) == op_EndExcept))
696 enter_procedure(block, cf_pred, pos);
697 if (get_irn_op(cf_pred) == op_CallBegin)
698 if (!leave_procedure(block, cf_pred, pos)) return NULL;
701 return get_irn_n(n, pos);
705 re_enter_procedure(ir_node *block, ir_node *cf_pred, int pos) {
706 ir_node *callbegin = pop_callsite(current_ir_graph);
707 assert(interprocedural_view);
708 current_ir_graph = get_CallBegin_irg(callbegin);
712 re_leave_procedure(ir_node *block, ir_node *cf_pred, int pos) {
716 assert(get_irn_op(cf_pred) == op_CallBegin);
718 /* Find the irg block is in. */
719 proj = get_Block_cg_cfgpred(block, pos);
720 assert(is_Proj(proj));
721 callee = get_entity_irg(get_Call_callee(get_CallBegin_call(cf_pred),
722 get_Proj_proj(proj)));
723 current_ir_graph = callee;
724 push_callsite(callee, cf_pred);
728 return_recur(ir_node *n, int pos) {
732 if (!interprocedural_view) return;
734 /* Find the cf_pred refering to pos. */
736 if (get_irn_opcode(n) == iro_Filter) block = get_nodes_block(n);
737 cf_pred = skip_Proj(get_irn_n(block, pos));
739 /* Check whether we re_enter or re_leave a procedure and act according. */
740 if ((get_irn_op(cf_pred) == op_EndReg) ||
741 (get_irn_op(cf_pred) == op_EndExcept))
742 re_enter_procedure(block, cf_pred, pos);
743 if (get_irn_op(cf_pred) == op_CallBegin)
744 re_leave_procedure(block, cf_pred, pos);