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 Intraprozedural analyses to estimate the call graph.
23 * @author Hubert Schmid
27 * Interprocedural analysis to estimate the calling relation.
29 * This analysis computes all entities representing methods that
30 * can be called at a Call node. Further it computes a set of
31 * methods that are 'free', i.e., their adress is handled by
32 * the program directly, or they are visible external.
52 #include "dbginfo_t.h"
53 #include "iropt_dbg.h"
62 /* unambiguous address used as a mark. */
63 static void *MARK = &MARK;
65 static eset *entities = NULL;
67 /*--------------------------------------------------------------------------*/
69 /*--------------------------------------------------------------------------*/
72 /*--------------------------------------------------------------------------*/
73 /* Initialize datastructures, remove unwanted constructs, optimize */
74 /* call target computations. */
75 /*--------------------------------------------------------------------------*/
77 /** Collect the entity representing the implementation of this
78 * method (not the same if inherited) and all entities for overwriting
79 * implementations in "set".
80 * If the implementation of the method is not included in the
81 * compilation unit "open" is set to true.
82 * A recursive descend in the overwritten relation.
83 * Cycle-free, therefore must terminate.
86 * @param set A set of entities.
87 * @param size Number of entities in set.
90 static void collect_impls(ir_entity *method, eset *set, int *size, int *open)
94 if (get_entity_irg(method) != NULL) {
95 eset_insert(set, method);
99 /*- recursive descent -*/
100 for (i = get_entity_n_overwrittenby(method) - 1; i >= 0; --i)
101 collect_impls(get_entity_overwrittenby(method, i), set, size, open);
104 /** Alle Methoden bestimmen, die die �bergebene Methode �berschreiben
105 * (und implementieren). In der zur�ckgegebenen Reihung kommt jede
106 * Methode nur einmal vor. Der Wert 'NULL' steht f�r unbekannte
107 * (externe) Methoden. Die zur�ckgegebene Reihung mu� vom Aufrufer
108 * wieder freigegeben werden (siehe "DEL_ARR_F"). Gibt es �berhaupt
109 * keine Methoden, die "method" �berschreiben, so gibt die Methode
114 static ir_entity ** get_impl_methods(ir_entity * method)
116 eset * set = eset_create();
121 /* Collect all method entities that can be called here */
122 collect_impls(method, set, &size, &open);
124 /* Vorgaenger einfuegen. */
125 if (size == 0 && !open) {
126 /* keine implementierte �berschriebene Methode */
130 arr = NEW_ARR_F(ir_entity *, size + 1);
131 arr[0] = NULL; /* Represents open method */
132 for (ent = eset_first(set); size > 0; ent = eset_next(set), --size)
136 arr = NEW_ARR_F(ir_entity *, size);
137 for (size -= 1, ent = eset_first(set); size >= 0; ent = eset_next(set), --size)
144 /** Analyze address computations.
146 * Compute for all Sel nodes the set of methods that can be selected.
147 * For each entity we store the set of subentities in the link field.
149 * Further do some optimizations:
150 * - Call standard optimizations for Sel nodes: this removes polymorphic
152 * - If the node is a SymConst(name) replace it by SymConst(ent) if possible.
153 * For this we precomputed a map name->entity. Nowadays, we no more support
155 * - If the node is a Sel:
156 * If we found only a single method that can be called, replace the Sel
157 * by a SymConst. This is more powerful than the analysis in opt_polymorphy,
158 * as here we walk the type graph. In opt_polymorphy we only apply a local
161 * @param node The node to analyze
162 * @param env A map that maps names of entities to the entities.
164 static void sel_methods_walker(ir_node *node, void *env)
166 pmap *ldname_map = env;
169 /* Call standard optimizations */
171 ir_node *new_node = optimize_in_place(node);
172 if (node != new_node) {
173 exchange(node, new_node);
178 /* replace SymConst(name)-operations by SymConst(ent) */
179 if (is_SymConst(node)) {
180 if (get_SymConst_kind(node) == symconst_addr_name) {
181 pmap_entry *entry = pmap_find(ldname_map, get_SymConst_name(node));
182 if (entry != NULL) { /* Method is declared in the compiled code */
183 assert(!"There should not be a SymConst[addr_name] addressing a method with an implementation"
184 "in this compilation unit. Use a SymConst[addr_ent].");
187 } else if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
188 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
190 if (!eset_contains(entities, ent)) {
191 /* Entity not yet handled. Find all (internal or external)
192 * implemented methods that overwrites this entity.
193 * This set is stored in the entity link. */
194 set_entity_link(ent, get_impl_methods(ent));
195 eset_insert(entities, ent);
198 /* -- As an add on we get an optimization that removes polymorphic calls.
199 This optimization is more powerful than that in transform_node_Sel(). -- */
200 arr = get_entity_link(ent);
203 * The Sel node never returns a pointer to a usable method.
204 * We could not call it, but it may be description:
205 * We call a method in a dead part of the program.
207 assert(get_entity_irg(ent) == NULL);
209 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
210 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
214 * The Sel node returns only one possible method.
215 * So we could replace the Sel node by a SymConst.
216 * This method must exists.
218 set_irg_current_block(current_ir_graph, get_nodes_block(node));
219 assert(get_entity_irg(arr[0]) != NULL);
220 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]));
221 DBG_OPT_POLY(node, new_node);
222 exchange(node, new_node);
228 * Initialize auxiliary data structures.
230 * Computes a set of entities that overwrite an entity and contain
231 * an implementation. The set is stored in the entity's link field.
233 * Further replaces Sel nodes where this set contains exactly one
234 * method by SymConst nodes.
235 * Finally asserts if there is a SymConst(name) if there could be a
238 static void sel_methods_init(void)
241 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
242 SymConst(name) by SymConst(ent). */
243 assert(entities == NULL);
244 entities = eset_create();
245 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
246 ir_entity * ent = get_irg_entity(get_irp_irg(i));
247 /* only external visible methods are allowed to call by a SymConst_ptr_name */
248 if (entity_is_externally_visible(ent)) {
249 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
253 all_irg_walk(sel_methods_walker, NULL, ldname_map);
254 pmap_destroy(ldname_map);
257 /*--------------------------------------------------------------------------*/
258 /* Find free methods.
260 * We expect that each entity has an array with all implementations in its
262 /*--------------------------------------------------------------------------*/
265 * Returns an array of all methods that could be called at a Sel node.
266 * This array contains every entry only once.
268 * @param sel the Sel node
270 static ir_entity ** get_Sel_arr(ir_node * sel)
272 static ir_entity ** NULL_ARRAY = NULL;
277 ent = get_Sel_entity(sel);
279 assert(is_Method_type(get_entity_type(ent))); /* what else? */
280 arr = get_entity_link(ent);
284 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
285 * kann f�r polymorphe (abstrakte) Methoden passieren. */
287 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
294 * Returns the number of possible called methods at a Sel node.
296 * @param sel the Sel node
298 static int get_Sel_n_methods(ir_node * sel)
300 return ARR_LEN(get_Sel_arr(sel));
304 * Returns the ith possible called method entity at a Sel node.
306 static ir_entity * get_Sel_method(ir_node * sel, int pos)
308 ir_entity ** arr = get_Sel_arr(sel);
309 assert(pos >= 0 && pos < ARR_LEN(arr));
314 static void free_mark(ir_node * node, eset * set);
316 static void free_mark_proj(ir_node * node, long n, eset * set)
318 assert(get_irn_mode(node) == mode_T);
319 if (get_irn_link(node) == MARK) {
320 /* already visited */
323 set_irn_link(node, MARK);
324 switch (get_irn_opcode(node)) {
326 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
327 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
329 ir_node * pred = get_Proj_pred(node);
330 if (get_irn_link(pred) != MARK && is_Tuple(pred)) {
331 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
333 /* nothing: da in "free_ana_walker" behandelt. */
339 free_mark(get_Tuple_pred(node, n), set);
343 free_mark_proj(get_Id_pred(node), n, set);
349 /* nothing: Die Operationen werden in free_ana_walker() selbst
354 assert(0 && "unexpected opcode or opcode not implemented");
357 // set_irn_link(node, NULL);
361 * Called for predecessors nodes of "interesting" ones.
362 * Interesting ones include all nodes that can somehow make
365 * If a method (or a set of methods in case of polymorph calls) gets visible,
366 * add it to the set of 'free' methods
368 * @param node the current visited node
369 * @param set the set of all free methods
371 static void free_mark(ir_node *node, eset * set)
375 if (get_irn_link(node) == MARK)
376 return; /* already visited */
378 set_irn_link(node, MARK);
380 switch (get_irn_opcode(node)) {
382 ir_entity *ent = get_Sel_entity(node);
383 if (is_method_entity(ent)) {
384 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
385 eset_insert(set, get_Sel_method(node, i));
391 if (get_SymConst_kind(node) == symconst_addr_ent) {
392 ir_entity *ent = get_SymConst_entity(node);
393 if (is_method_entity(ent)) {
394 eset_insert(set, ent);
400 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
401 free_mark(get_Phi_pred(node, i), set);
405 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
414 * post-walker. Find method addresses.
416 static void free_ana_walker(ir_node *node, void *env)
421 if (get_irn_link(node) == MARK) {
422 /* already visited */
425 switch (get_irn_opcode(node)) {
437 /* we must handle Call nodes specially, because their call address input
438 do not expose a method address. */
439 set_irn_link(node, MARK);
440 for (i = get_Call_n_params(node) - 1; i >= 0; --i) {
441 ir_node *pred = get_Call_param(node, i);
442 if (mode_is_reference(get_irn_mode(pred))) {
443 free_mark(pred, set);
448 /* other nodes: Alle anderen Knoten nehmen wir als Verr�ter an, bis
449 * jemand das Gegenteil implementiert. */
450 set_irn_link(node, MARK);
451 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
452 ir_node *pred = get_irn_n(node, i);
453 if (mode_is_reference(get_irn_mode(pred))) {
454 free_mark(pred, set);
462 * Add all method addresses in global new style initializers to the set.
465 * We do NOT check the type here, just it it's an entity address.
466 * The reason for this is code like:
468 * void *p = function;
470 * which is sometimes used to anchor functions.
472 static void add_method_address_inititializer(ir_initializer_t *initializer,
478 switch (initializer->kind) {
479 case IR_INITIALIZER_CONST:
480 n = initializer->consti.value;
482 /* let's check if it's the address of a function */
484 ir_entity *ent = get_Global_entity(n);
486 if (is_Method_type(get_entity_type(ent)))
487 eset_insert(set, ent);
490 case IR_INITIALIZER_TARVAL:
491 case IR_INITIALIZER_NULL:
493 case IR_INITIALIZER_COMPOUND:
494 for (i = 0; i < initializer->compound.n_initializers; ++i) {
495 ir_initializer_t *sub_initializer
496 = initializer->compound.initializers[i];
497 add_method_address_inititializer(sub_initializer, set);
501 panic("invalid initializer found");
505 * Add all method addresses in global initializers to the set.
508 * We do NOT check the type here, just it it's an entity address.
509 * The reason for this is code like:
511 * void *p = function;
513 * which is sometimes used to anchor functions.
515 static void add_method_address(ir_entity *ent, eset *set)
521 /* ignore methods: these of course reference it's address
522 * TODO: remove this later once this incorrect self-intialisation is gone
524 tp = get_entity_type(ent);
525 if (is_Method_type(tp))
528 if (ent->initializer != NULL) {
529 add_method_address_inititializer(get_entity_initializer(ent), set);
530 } else if (entity_has_compound_ent_values(ent)) {
531 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
532 n = get_compound_ent_value(ent, i);
534 /* let's check if it's the address of a function */
536 ir_entity *ent = get_Global_entity(n);
538 if (is_Method_type(get_entity_type(ent)))
539 eset_insert(set, ent);
546 * returns a list of 'free' methods, i.e., the methods that can be called
547 * from external or via function pointers.
549 * Die Datenstrukturen für sel-Methoden (sel_methods) muß vor dem
550 * Aufruf von "get_free_methods" aufgebaut sein. Die (internen)
551 * SymConst(name)-Operationen müssen in passende SymConst(ent)-Operationen
552 * umgewandelt worden sein, d.h. SymConst-Operationen verweisen immer
553 * auf eine echt externe Methode.
555 static ir_entity **get_free_methods(int *length)
557 eset *free_set = eset_create();
564 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
566 irg = get_irp_irg(i);
567 ent = get_irg_entity(irg);
568 linkage = get_entity_linkage(ent);
570 if (entity_is_externally_visible(ent)
571 || (linkage & IR_LINKAGE_HIDDEN_USER)) {
572 eset_insert(free_set, ent);
575 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
576 /* Find all method entities that gets "visible" through this graphs,
577 * for instance because their address is stored. */
578 irg_walk_graph(irg, firm_clear_link, free_ana_walker, free_set);
579 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
582 /* insert all methods that are used in global variables initializers */
583 tp = get_glob_type();
584 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
585 ent = get_class_member(tp, i);
586 add_method_address(ent, free_set);
589 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
590 ent = get_class_member(tp, i);
591 add_method_address(ent, free_set);
594 /* the main program is even then "free", if it's not external visible. */
595 irg = get_irp_main_irg();
597 eset_insert(free_set, get_irg_entity(irg));
599 /* Finally, transform the set into an array. */
600 *length = eset_count(free_set);
601 arr = XMALLOCN(ir_entity*, *length);
602 for (i = 0, ent = eset_first(free_set); ent; ent = eset_next(free_set)) {
605 eset_destroy(free_set);
610 /*--------------------------------------------------------------------------*/
611 /* Callee analysis. */
612 /*--------------------------------------------------------------------------*/
614 static void callee_ana_node(ir_node * node, eset * methods);
616 static void callee_ana_proj(ir_node *node, long n, eset *methods)
618 assert(get_irn_mode(node) == mode_T);
619 if (get_irn_link(node) == MARK) {
620 /* already visited */
623 set_irn_link(node, MARK);
625 switch (get_irn_opcode(node)) {
627 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
628 * op_Tuple oder ein Knoten, der eine "freie Methode"
630 ir_node *pred = get_Proj_pred(node);
631 if (get_irn_link(pred) != MARK) {
632 if (is_Tuple(pred)) {
633 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
635 eset_insert(methods, unknown_entity); /* free method -> unknown */
642 callee_ana_node(get_Tuple_pred(node, n), methods);
646 eset_insert(methods, unknown_entity); /* free method -> unknown */
652 * Analyse a Call address.
654 * @param node the node representing the call address
655 * @param methods after call contains the set of all possibly called entities
657 static void callee_ana_node(ir_node *node, eset *methods)
661 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
662 /* Beware of recursion */
663 if (get_irn_link(node) == MARK) {
664 /* already visited */
667 set_irn_link(node, MARK);
669 switch (get_irn_opcode(node)) {
671 /* A direct address call. We tread this as an external
672 call and ignore it completely. */
673 eset_insert(methods, unknown_entity); /* free method -> unknown */
676 if (get_SymConst_kind(node) == symconst_addr_ent) {
677 ir_entity *ent = get_SymConst_entity(node);
678 assert(ent && is_method_entity(ent));
679 eset_insert(methods, ent);
681 assert(get_SymConst_kind(node) == symconst_addr_name);
682 /* external method (because fix_symconst()!) */
683 eset_insert(methods, unknown_entity); /* free method -> unknown */
687 /* polymorphic method */
688 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
689 ir_entity *ent = get_Sel_method(node, i);
691 eset_insert(methods, ent);
693 eset_insert(methods, unknown_entity);
703 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
704 callee_ana_node(get_Phi_pred(node, i), methods);
709 callee_ana_node(get_Mux_false(node), methods);
710 callee_ana_node(get_Mux_true(node), methods);
714 callee_ana_node(get_Id_pred(node), methods);
718 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
725 eset_insert(methods, unknown_entity); /* free method -> unknown */
729 assert(0 && "invalid opcode or opcode not implemented");
735 * Walker: Analyses every Call node and calculates an array of possible
736 * callees for that call.
738 static void callee_walker(ir_node *call, void *env)
742 eset *methods = eset_create();
747 callee_ana_node(get_Call_ptr(call), methods);
748 arr = NEW_ARR_F(ir_entity *, eset_count(methods));
749 for (i = 0, ent = eset_first(methods); ent; ent = eset_next(methods)) {
751 /* we want the unknown_entity on the zero position for easy tests later */
752 if (ent == unknown_entity) {
754 arr[0] = unknown_entity;
758 set_Call_callee_arr(call, ARR_LEN(arr), arr);
760 eset_destroy(methods);
765 * Walker: Removes all tuple.
767 static void remove_Tuples(ir_node *proj, void *env)
771 if (! is_Proj(proj)) return;
773 nn = skip_Tuple(proj);
774 if (nn != proj) exchange(proj, nn);
779 * Determine for every Call the set of possibly called methods and stores it
780 * inside the Call (@see set_Call_callee()).
781 * Uses the sel_methods set with much be already calculated.
783 static void callee_ana(void)
786 /* analyse all graphs */
787 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
788 ir_graph *irg = get_irp_irg(i);
789 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
790 set_irg_callee_info_state(irg, irg_callee_info_consistent);
792 set_irp_callee_info_state(irg_callee_info_consistent);
795 /*--------------------------------------------------------------------------*/
796 /* Cleanup after analyses. */
797 /*--------------------------------------------------------------------------*/
799 /** Frees intermediate data structures. */
800 static void sel_methods_dispose(void)
804 for (ent = eset_first(entities); ent; ent = eset_next(entities)) {
805 ir_entity ** arr = get_entity_link(ent);
809 set_entity_link(ent, NULL);
811 eset_destroy(entities);
815 /*--------------------------------------------------------------------------*/
816 /* Freeing the callee arrays. */
817 /*--------------------------------------------------------------------------*/
819 static void destruct_walker(ir_node * node, void * env)
823 remove_Call_callee_arr(node);
827 /*--------------------------------------------------------------------------*/
829 /*--------------------------------------------------------------------------*/
831 void cgana(int *length, ir_entity ***free_methods)
833 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
835 *free_methods = get_free_methods(length);
837 sel_methods_dispose();
840 void free_callee_info(ir_graph *irg)
842 irg_walk_graph(irg, destruct_walker, NULL, NULL);
843 set_irg_callee_info_state(irg, irg_callee_info_none);
846 void free_irp_callee_info(void)
849 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
850 free_callee_info(get_irp_irg(i));
854 /* Optimize the address expressions passed to call nodes.
856 * This optimization performs the following transformations for
858 * - All SymConst operations that refer to intern methods are replaced
859 * by Const operations referring to the corresponding entity.
860 * - Sel nodes, that select entities that are not overwritten are
861 * replaced by Const nodes referring to the selected entity.
862 * - Sel nodes, for which no method exists at all are replaced by Bad
864 * - Sel nodes with a pointer input that is an Alloc node are replaced
865 * by Const nodes referring to the entity that implements the method in
866 * the type given by the Alloc node.
868 void opt_call_addrs(void)
871 sel_methods_dispose();