2 * Copyright (C) 1995-2011 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 Intraprozedural analyses to estimate the call graph.
23 * @author Hubert Schmid
26 * Interprocedural analysis to estimate the calling relation.
28 * This analysis computes all entities representing methods that
29 * can be called at a Call node. Further it computes a set of
30 * methods that are 'free', i.e., their adress is handled by
31 * the program directly, or they are visible external.
50 #include "dbginfo_t.h"
51 #include "iropt_dbg.h"
59 /* unambiguous address used as a mark. */
60 static void *MARK = &MARK;
62 static pset *entities = NULL;
64 /*--------------------------------------------------------------------------*/
66 /*--------------------------------------------------------------------------*/
69 /*--------------------------------------------------------------------------*/
70 /* Initialize datastructures, remove unwanted constructs, optimize */
71 /* call target computations. */
72 /*--------------------------------------------------------------------------*/
74 /** Collect the entity representing the implementation of this
75 * method (not the same if inherited) and all entities for overwriting
76 * implementations in parameter set.
77 * A recursive descend in the overwritten relation.
78 * Cycle-free, therefore must terminate.
80 * @param method the overwritten method
81 * @param set A set of entities.
83 * @return Number of entities in set.
85 static size_t collect_impls(ir_entity *method, pset *set)
90 if (get_entity_irg(method) != NULL) {
91 /* has an implementation */
92 pset_insert_ptr(set, method);
96 /*- recursive descent -*/
97 for (i = get_entity_n_overwrittenby(method); i > 0;)
98 size += collect_impls(get_entity_overwrittenby(method, --i), set);
103 * Determine all methods that overwrite the given method (and implement it).
104 * The returned array must be freed by the caller (see DEL_ARR_F).
105 * If the set of overwriting methods is empty, returns NULL.
107 * @param method the method
109 static ir_entity **get_impl_methods(ir_entity *method)
112 pset *set = pset_new_ptr_default();
115 /* Collect all method entities that can be called here */
116 size = collect_impls(method, set);
119 /* no overwriting methods found */
122 arr = NEW_ARR_F(ir_entity *, size);
123 foreach_pset(set, ir_entity, ent) {
131 /** Analyze address computations.
133 * Compute for all Sel nodes the set of methods that can be selected.
134 * For each entity we store the set of subentities in the link field.
136 * Further do some optimizations:
137 * - Call standard optimizations for Sel nodes: this removes polymorphic
139 * - If the node is a SymConst(name) replace it by SymConst(ent) if possible.
140 * For this we precomputed a map name->entity. Nowadays, we no more support
142 * - If the node is a Sel:
143 * If we found only a single method that can be called, replace the Sel
144 * by a SymConst. This is more powerful than the analysis in opt_polymorphy,
145 * as here we walk the type graph. In opt_polymorphy we only apply a local
148 * @param node The node to analyze
149 * @param env A map that maps names of entities to the entities.
151 static void sel_methods_walker(ir_node *node, void *env)
156 /* Call standard optimizations */
158 ir_node *new_node = optimize_in_place(node);
159 if (node != new_node) {
160 exchange(node, new_node);
165 if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
166 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
168 if (!pset_find_ptr(entities, ent)) {
169 /* Entity not yet handled. Find all (internal or external)
170 * implemented methods that overwrites this entity.
171 * This set is stored in the entity link. */
172 set_entity_link(ent, get_impl_methods(ent));
173 pset_insert_ptr(entities, ent);
176 /* -- As an add on we get an optimization that removes polymorphic calls.
177 This optimization is more powerful than that in transform_node_Sel(). -- */
178 arr = (ir_entity**) get_entity_link(ent);
181 * The Sel node never returns a pointer to a usable method.
182 * We could not call it, but it may be description:
183 * We call a method in a dead part of the program.
185 assert(get_entity_irg(ent) == NULL);
191 * Initialize auxiliary data structures.
193 * Computes a set of entities that overwrite an entity and contain
194 * an implementation. The set is stored in the entity's link field.
196 * Further replaces Sel nodes where this set contains exactly one
197 * method by SymConst nodes.
198 * Finally asserts if there is a SymConst(name) if there could be a
201 static void sel_methods_init(void)
204 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
205 SymConst(name) by SymConst(ent). */
206 assert(entities == NULL);
207 entities = pset_new_ptr_default();
208 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
209 ir_entity * ent = get_irg_entity(get_irp_irg(i));
210 /* only external visible methods are allowed to call by a SymConst_ptr_name */
211 if (entity_is_externally_visible(ent)) {
212 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
216 all_irg_walk(sel_methods_walker, NULL, NULL);
217 pmap_destroy(ldname_map);
220 /*--------------------------------------------------------------------------*/
221 /* Find free methods.
223 * We expect that each entity has an array with all implementations in its
225 /*--------------------------------------------------------------------------*/
228 * Returns an array of all methods that could be called at a Sel node.
229 * This array contains every entry only once.
231 * @param sel the Sel node
233 static ir_entity ** get_Sel_arr(ir_node * sel)
235 static ir_entity ** NULL_ARRAY = NULL;
237 ir_entity *const ent = get_Sel_entity(sel);
238 assert(is_Method_type(get_entity_type(ent))); /* what else? */
240 ir_entity **const arr = (ir_entity**)get_entity_link(ent);
244 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
245 * kann f�r polymorphe (abstrakte) Methoden passieren. */
247 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
254 * Returns the number of possible called methods at a Sel node.
256 * @param sel the Sel node
258 static size_t get_Sel_n_methods(ir_node * sel)
260 return ARR_LEN(get_Sel_arr(sel));
264 * Returns the ith possible called method entity at a Sel node.
266 static ir_entity * get_Sel_method(ir_node * sel, size_t pos)
268 ir_entity ** arr = get_Sel_arr(sel);
269 assert(pos < ARR_LEN(arr));
274 static void free_mark(ir_node *node, pset *set);
276 static void free_mark_proj(ir_node *node, long n, pset *set)
278 assert(get_irn_mode(node) == mode_T);
279 if (get_irn_link(node) == MARK) {
280 /* already visited */
283 set_irn_link(node, MARK);
284 switch (get_irn_opcode(node)) {
286 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
287 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
289 ir_node * pred = get_Proj_pred(node);
290 if (get_irn_link(pred) != MARK && is_Tuple(pred)) {
291 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
293 /* nothing: da in "free_ana_walker" behandelt. */
299 free_mark(get_Tuple_pred(node, n), set);
303 free_mark_proj(get_Id_pred(node), n, set);
309 /* nothing: Die Operationen werden in free_ana_walker() selbst
314 assert(0 && "unexpected opcode or opcode not implemented");
317 // set_irn_link(node, NULL);
321 * Called for predecessors nodes of "interesting" ones.
322 * Interesting ones include all nodes that can somehow make
325 * If a method (or a set of methods in case of polymorph calls) gets visible,
326 * add it to the set of 'free' methods
328 * @param node the current visited node
329 * @param set the set of all free methods
331 static void free_mark(ir_node *node, pset *set)
333 if (get_irn_link(node) == MARK)
334 return; /* already visited */
336 set_irn_link(node, MARK);
338 switch (get_irn_opcode(node)) {
340 ir_entity *ent = get_Sel_entity(node);
341 if (is_method_entity(ent)) {
343 for (i = 0, n = get_Sel_n_methods(node); i < n; ++i) {
344 pset_insert_ptr(set, get_Sel_method(node, i));
350 if (get_SymConst_kind(node) == symconst_addr_ent) {
351 ir_entity *ent = get_SymConst_entity(node);
352 if (is_method_entity(ent)) {
353 pset_insert_ptr(set, ent);
361 for (i = 0, n = get_Phi_n_preds(node); i < n; ++i) {
362 free_mark(get_Phi_pred(node, i), set);
367 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
376 * post-walker. Find method addresses.
378 static void free_ana_walker(ir_node *node, void *env)
380 pset *set = (pset*) env;
382 if (get_irn_link(node) == MARK) {
383 /* already visited */
386 switch (get_irn_opcode(node)) {
400 /* we must handle Call nodes specially, because their call address input
401 do not expose a method address. */
402 set_irn_link(node, MARK);
403 for (i = 0, n = get_Call_n_params(node); i < n; ++i) {
404 ir_node *pred = get_Call_param(node, i);
405 if (mode_is_reference(get_irn_mode(pred))) {
406 free_mark(pred, set);
413 /* other nodes: Alle anderen Knoten nehmen wir als Verr�ter an, bis
414 * jemand das Gegenteil implementiert. */
415 set_irn_link(node, MARK);
416 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
417 ir_node *pred = get_irn_n(node, i);
418 if (mode_is_reference(get_irn_mode(pred))) {
419 free_mark(pred, set);
428 * Add all method addresses in global new style initializers to the set.
431 * We do NOT check the type here, just if it's an entity address.
432 * The reason for this is code like:
434 * void *p = function;
436 * which is sometimes used to anchor functions.
438 static void add_method_address_inititializer(ir_initializer_t *initializer,
444 switch (initializer->kind) {
445 case IR_INITIALIZER_CONST:
446 n = initializer->consti.value;
448 /* let's check if it's the address of a function */
449 if (is_SymConst_addr_ent(n)) {
450 ir_entity *ent = get_SymConst_entity(n);
452 if (is_Method_type(get_entity_type(ent)))
453 pset_insert_ptr(set, ent);
456 case IR_INITIALIZER_TARVAL:
457 case IR_INITIALIZER_NULL:
459 case IR_INITIALIZER_COMPOUND:
460 for (i = 0; i < initializer->compound.n_initializers; ++i) {
461 ir_initializer_t *sub_initializer
462 = initializer->compound.initializers[i];
463 add_method_address_inititializer(sub_initializer, set);
467 panic("invalid initializer found");
471 * Add all method addresses in global initializers to the set.
474 * We do NOT check the type here, just if it's an entity address.
475 * The reason for this is code like:
477 * void *p = function;
479 * which is sometimes used to anchor functions.
481 static void add_method_address(ir_entity *ent, pset *set)
485 /* ignore methods: these of course reference their addresses
486 * TODO: remove this later once this incorrect self-initialisation is gone
488 tp = get_entity_type(ent);
489 if (is_Method_type(tp))
492 if (ent->initializer != NULL) {
493 add_method_address_inititializer(get_entity_initializer(ent), set);
498 * returns a list of 'free' methods, i.e., the methods that can be called
499 * from external or via function pointers.
501 * Die Datenstrukturen für sel-Methoden (sel_methods) muß vor dem
502 * Aufruf von "get_free_methods" aufgebaut sein. Die (internen)
503 * SymConst(name)-Operationen müssen in passende SymConst(ent)-Operationen
504 * umgewandelt worden sein, d.h. SymConst-Operationen verweisen immer
505 * auf eine echt externe Methode.
507 static size_t get_free_methods(ir_entity ***free_methods)
509 pset *free_set = pset_new_ptr_default();
516 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
518 irg = get_irp_irg(i);
519 ir_entity *const ent = get_irg_entity(irg);
520 linkage = get_entity_linkage(ent);
522 if ((linkage & IR_LINKAGE_HIDDEN_USER) || entity_is_externally_visible(ent)) {
523 pset_insert_ptr(free_set, ent);
526 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
527 /* Find all method entities that gets "visible" through this graphs,
528 * for instance because their address is stored. */
529 irg_walk_graph(irg, firm_clear_link, free_ana_walker, free_set);
530 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
533 /* insert all methods that are used in global variables initializers */
534 tp = get_glob_type();
535 for (j = 0, m = get_class_n_members(tp); j < m; ++j) {
536 ir_entity *const ent = get_class_member(tp, j);
537 add_method_address(ent, free_set);
540 for (j = 0, m = get_compound_n_members(tp); j < m; ++j) {
541 ir_entity *const ent = get_compound_member(tp, j);
542 add_method_address(ent, free_set);
545 /* the main program is even then "free", if it's not external visible. */
546 irg = get_irp_main_irg();
548 pset_insert_ptr(free_set, get_irg_entity(irg));
550 /* Finally, transform the set into an array. */
551 length = pset_count(free_set);
552 arr = XMALLOCN(ir_entity*, length);
554 foreach_pset(free_set, ir_entity, ent) {
563 /*--------------------------------------------------------------------------*/
564 /* Callee analysis. */
565 /*--------------------------------------------------------------------------*/
567 static void callee_ana_node(ir_node *node, pset *methods);
569 static void callee_ana_proj(ir_node *node, long n, pset *methods)
571 assert(get_irn_mode(node) == mode_T);
572 if (get_irn_link(node) == MARK) {
573 /* already visited */
576 set_irn_link(node, MARK);
578 switch (get_irn_opcode(node)) {
580 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
581 * op_Tuple oder ein Knoten, der eine "freie Methode"
583 ir_node *pred = get_Proj_pred(node);
584 if (get_irn_link(pred) != MARK) {
585 if (is_Tuple(pred)) {
586 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
588 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
595 callee_ana_node(get_Tuple_pred(node, n), methods);
599 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
605 * Analyse a Call address.
607 * @param node the node representing the call address
608 * @param methods after call contains the set of all possibly called entities
610 static void callee_ana_node(ir_node *node, pset *methods)
612 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
613 /* Beware of recursion */
614 if (get_irn_link(node) == MARK) {
615 /* already visited */
618 set_irn_link(node, MARK);
620 switch (get_irn_opcode(node)) {
622 /* A direct address call. We tread this as an external
623 call and ignore it completely. */
624 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
628 ir_entity *ent = get_SymConst_entity(node);
629 assert(ent && is_method_entity(ent));
630 pset_insert_ptr(methods, ent);
635 /* polymorphic method */
637 for (i = 0, n = get_Sel_n_methods(node); i < n; ++i) {
638 ir_entity *ent = get_Sel_method(node, i);
640 pset_insert_ptr(methods, ent);
642 pset_insert_ptr(methods, get_unknown_entity());
654 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
655 callee_ana_node(get_Phi_pred(node, i), methods);
661 callee_ana_node(get_Mux_false(node), methods);
662 callee_ana_node(get_Mux_true(node), methods);
666 callee_ana_node(get_Id_pred(node), methods);
670 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
677 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
681 assert(0 && "invalid opcode or opcode not implemented");
687 * Walker: Analyses every Call node and calculates an array of possible
688 * callees for that call.
690 static void callee_walker(ir_node *call, void *env)
694 pset *methods = pset_new_ptr_default();
698 callee_ana_node(get_Call_ptr(call), methods);
699 arr = NEW_ARR_F(ir_entity*, pset_count(methods));
701 foreach_pset(methods, ir_entity, ent) {
703 /* we want the unknown_entity on the zero position for easy tests later */
704 if (is_unknown_entity(ent)) {
706 arr[0] = get_unknown_entity();
710 set_Call_callee_arr(call, ARR_LEN(arr), arr);
717 * Walker: Removes all tuple.
719 static void remove_Tuples(ir_node *proj, void *env)
723 if (! is_Proj(proj)) return;
725 nn = skip_Tuple(proj);
726 if (nn != proj) exchange(proj, nn);
731 * Determine for every Call the set of possibly called methods and stores it
732 * inside the Call (@see set_Call_callee()).
733 * Uses the sel_methods set with much be already calculated.
735 static void callee_ana(void)
738 /* analyse all graphs */
739 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
740 ir_graph *irg = get_irp_irg(i);
741 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
742 set_irg_callee_info_state(irg, irg_callee_info_consistent);
744 set_irp_callee_info_state(irg_callee_info_consistent);
747 /*--------------------------------------------------------------------------*/
748 /* Cleanup after analyses. */
749 /*--------------------------------------------------------------------------*/
751 /** Frees intermediate data structures. */
752 static void sel_methods_dispose(void)
755 foreach_pset(entities, ir_entity, ent) {
756 ir_entity **arr = (ir_entity**) get_entity_link(ent);
760 set_entity_link(ent, NULL);
766 static void destruct_walker(ir_node * node, void * env)
770 remove_Call_callee_arr(node);
774 size_t cgana(ir_entity ***free_methods)
777 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
779 length = get_free_methods(free_methods);
781 sel_methods_dispose();
785 void free_callee_info(ir_graph *irg)
787 irg_walk_graph(irg, destruct_walker, NULL, NULL);
788 set_irg_callee_info_state(irg, irg_callee_info_none);
791 void free_irp_callee_info(void)
794 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
795 free_callee_info(get_irp_irg(i));
799 void opt_call_addrs(void)
801 /* Optimize the address expressions passed to call nodes.
803 * This optimization performs the following transformations for
805 * - All SymConst operations that refer to intern methods are replaced
806 * by Const operations referring to the corresponding entity.
807 * - Sel nodes, that select entities that are not overwritten are
808 * replaced by Const nodes referring to the selected entity.
809 * - Sel nodes, for which no method exists at all are replaced by Bad
811 * - Sel nodes with a pointer input that is an Alloc node are replaced
812 * by Const nodes referring to the entity that implements the method in
813 * the type given by the Alloc node.
816 sel_methods_dispose();