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)
169 /* Call standard optimizations */
171 ir_node *new_node = optimize_in_place(node);
172 if (node != new_node) {
173 exchange(node, new_node);
178 if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
179 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
181 if (!eset_contains(entities, ent)) {
182 /* Entity not yet handled. Find all (internal or external)
183 * implemented methods that overwrites this entity.
184 * This set is stored in the entity link. */
185 set_entity_link(ent, get_impl_methods(ent));
186 eset_insert(entities, ent);
189 /* -- As an add on we get an optimization that removes polymorphic calls.
190 This optimization is more powerful than that in transform_node_Sel(). -- */
191 arr = get_entity_link(ent);
194 * The Sel node never returns a pointer to a usable method.
195 * We could not call it, but it may be description:
196 * We call a method in a dead part of the program.
198 assert(get_entity_irg(ent) == NULL);
200 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
201 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
205 * The Sel node returns only one possible method.
206 * So we could replace the Sel node by a SymConst.
207 * This method must exists.
209 assert(get_entity_irg(arr[0]) != NULL);
210 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]), get_nodes_block(node));
211 DBG_OPT_POLY(node, new_node);
212 exchange(node, new_node);
218 * Initialize auxiliary data structures.
220 * Computes a set of entities that overwrite an entity and contain
221 * an implementation. The set is stored in the entity's link field.
223 * Further replaces Sel nodes where this set contains exactly one
224 * method by SymConst nodes.
225 * Finally asserts if there is a SymConst(name) if there could be a
228 static void sel_methods_init(void)
231 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
232 SymConst(name) by SymConst(ent). */
233 assert(entities == NULL);
234 entities = eset_create();
235 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
236 ir_entity * ent = get_irg_entity(get_irp_irg(i));
237 /* only external visible methods are allowed to call by a SymConst_ptr_name */
238 if (entity_is_externally_visible(ent)) {
239 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
243 all_irg_walk(sel_methods_walker, NULL, NULL);
244 pmap_destroy(ldname_map);
247 /*--------------------------------------------------------------------------*/
248 /* Find free methods.
250 * We expect that each entity has an array with all implementations in its
252 /*--------------------------------------------------------------------------*/
255 * Returns an array of all methods that could be called at a Sel node.
256 * This array contains every entry only once.
258 * @param sel the Sel node
260 static ir_entity ** get_Sel_arr(ir_node * sel)
262 static ir_entity ** NULL_ARRAY = NULL;
267 ent = get_Sel_entity(sel);
269 assert(is_Method_type(get_entity_type(ent))); /* what else? */
270 arr = get_entity_link(ent);
274 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
275 * kann f�r polymorphe (abstrakte) Methoden passieren. */
277 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
284 * Returns the number of possible called methods at a Sel node.
286 * @param sel the Sel node
288 static int get_Sel_n_methods(ir_node * sel)
290 return ARR_LEN(get_Sel_arr(sel));
294 * Returns the ith possible called method entity at a Sel node.
296 static ir_entity * get_Sel_method(ir_node * sel, int pos)
298 ir_entity ** arr = get_Sel_arr(sel);
299 assert(pos >= 0 && pos < ARR_LEN(arr));
304 static void free_mark(ir_node * node, eset * set);
306 static void free_mark_proj(ir_node * node, long n, eset * set)
308 assert(get_irn_mode(node) == mode_T);
309 if (get_irn_link(node) == MARK) {
310 /* already visited */
313 set_irn_link(node, MARK);
314 switch (get_irn_opcode(node)) {
316 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
317 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
319 ir_node * pred = get_Proj_pred(node);
320 if (get_irn_link(pred) != MARK && is_Tuple(pred)) {
321 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
323 /* nothing: da in "free_ana_walker" behandelt. */
329 free_mark(get_Tuple_pred(node, n), set);
333 free_mark_proj(get_Id_pred(node), n, set);
339 /* nothing: Die Operationen werden in free_ana_walker() selbst
344 assert(0 && "unexpected opcode or opcode not implemented");
347 // set_irn_link(node, NULL);
351 * Called for predecessors nodes of "interesting" ones.
352 * Interesting ones include all nodes that can somehow make
355 * If a method (or a set of methods in case of polymorph calls) gets visible,
356 * add it to the set of 'free' methods
358 * @param node the current visited node
359 * @param set the set of all free methods
361 static void free_mark(ir_node *node, eset * set)
365 if (get_irn_link(node) == MARK)
366 return; /* already visited */
368 set_irn_link(node, MARK);
370 switch (get_irn_opcode(node)) {
372 ir_entity *ent = get_Sel_entity(node);
373 if (is_method_entity(ent)) {
374 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
375 eset_insert(set, get_Sel_method(node, i));
381 if (get_SymConst_kind(node) == symconst_addr_ent) {
382 ir_entity *ent = get_SymConst_entity(node);
383 if (is_method_entity(ent)) {
384 eset_insert(set, ent);
390 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
391 free_mark(get_Phi_pred(node, i), set);
395 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
404 * post-walker. Find method addresses.
406 static void free_ana_walker(ir_node *node, void *env)
411 if (get_irn_link(node) == MARK) {
412 /* already visited */
415 switch (get_irn_opcode(node)) {
427 /* we must handle Call nodes specially, because their call address input
428 do not expose a method address. */
429 set_irn_link(node, MARK);
430 for (i = get_Call_n_params(node) - 1; i >= 0; --i) {
431 ir_node *pred = get_Call_param(node, i);
432 if (mode_is_reference(get_irn_mode(pred))) {
433 free_mark(pred, set);
438 /* other nodes: Alle anderen Knoten nehmen wir als Verr�ter an, bis
439 * jemand das Gegenteil implementiert. */
440 set_irn_link(node, MARK);
441 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
442 ir_node *pred = get_irn_n(node, i);
443 if (mode_is_reference(get_irn_mode(pred))) {
444 free_mark(pred, set);
452 * Add all method addresses in global new style initializers to the set.
455 * We do NOT check the type here, just it it's an entity address.
456 * The reason for this is code like:
458 * void *p = function;
460 * which is sometimes used to anchor functions.
462 static void add_method_address_inititializer(ir_initializer_t *initializer,
468 switch (initializer->kind) {
469 case IR_INITIALIZER_CONST:
470 n = initializer->consti.value;
472 /* let's check if it's the address of a function */
474 ir_entity *ent = get_Global_entity(n);
476 if (is_Method_type(get_entity_type(ent)))
477 eset_insert(set, ent);
480 case IR_INITIALIZER_TARVAL:
481 case IR_INITIALIZER_NULL:
483 case IR_INITIALIZER_COMPOUND:
484 for (i = 0; i < initializer->compound.n_initializers; ++i) {
485 ir_initializer_t *sub_initializer
486 = initializer->compound.initializers[i];
487 add_method_address_inititializer(sub_initializer, set);
491 panic("invalid initializer found");
495 * Add all method addresses in global initializers to the set.
498 * We do NOT check the type here, just it it's an entity address.
499 * The reason for this is code like:
501 * void *p = function;
503 * which is sometimes used to anchor functions.
505 static void add_method_address(ir_entity *ent, eset *set)
511 /* ignore methods: these of course reference it's address
512 * TODO: remove this later once this incorrect self-intialisation is gone
514 tp = get_entity_type(ent);
515 if (is_Method_type(tp))
518 if (ent->initializer != NULL) {
519 add_method_address_inititializer(get_entity_initializer(ent), set);
520 } else if (entity_has_compound_ent_values(ent)) {
521 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
522 n = get_compound_ent_value(ent, i);
524 /* let's check if it's the address of a function */
526 ir_entity *ent = get_Global_entity(n);
528 if (is_Method_type(get_entity_type(ent)))
529 eset_insert(set, ent);
536 * returns a list of 'free' methods, i.e., the methods that can be called
537 * from external or via function pointers.
539 * Die Datenstrukturen für sel-Methoden (sel_methods) muß vor dem
540 * Aufruf von "get_free_methods" aufgebaut sein. Die (internen)
541 * SymConst(name)-Operationen müssen in passende SymConst(ent)-Operationen
542 * umgewandelt worden sein, d.h. SymConst-Operationen verweisen immer
543 * auf eine echt externe Methode.
545 static ir_entity **get_free_methods(int *length)
547 eset *free_set = eset_create();
554 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
556 irg = get_irp_irg(i);
557 ent = get_irg_entity(irg);
558 linkage = get_entity_linkage(ent);
560 if (entity_is_externally_visible(ent)
561 || (linkage & IR_LINKAGE_HIDDEN_USER)) {
562 eset_insert(free_set, ent);
565 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
566 /* Find all method entities that gets "visible" through this graphs,
567 * for instance because their address is stored. */
568 irg_walk_graph(irg, firm_clear_link, free_ana_walker, free_set);
569 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
572 /* insert all methods that are used in global variables initializers */
573 tp = get_glob_type();
574 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
575 ent = get_class_member(tp, i);
576 add_method_address(ent, free_set);
579 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
580 ent = get_class_member(tp, i);
581 add_method_address(ent, free_set);
584 /* the main program is even then "free", if it's not external visible. */
585 irg = get_irp_main_irg();
587 eset_insert(free_set, get_irg_entity(irg));
589 /* Finally, transform the set into an array. */
590 *length = eset_count(free_set);
591 arr = XMALLOCN(ir_entity*, *length);
592 for (i = 0, ent = eset_first(free_set); ent; ent = eset_next(free_set)) {
595 eset_destroy(free_set);
600 /*--------------------------------------------------------------------------*/
601 /* Callee analysis. */
602 /*--------------------------------------------------------------------------*/
604 static void callee_ana_node(ir_node * node, eset * methods);
606 static void callee_ana_proj(ir_node *node, long n, eset *methods)
608 assert(get_irn_mode(node) == mode_T);
609 if (get_irn_link(node) == MARK) {
610 /* already visited */
613 set_irn_link(node, MARK);
615 switch (get_irn_opcode(node)) {
617 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
618 * op_Tuple oder ein Knoten, der eine "freie Methode"
620 ir_node *pred = get_Proj_pred(node);
621 if (get_irn_link(pred) != MARK) {
622 if (is_Tuple(pred)) {
623 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
625 eset_insert(methods, unknown_entity); /* free method -> unknown */
632 callee_ana_node(get_Tuple_pred(node, n), methods);
636 eset_insert(methods, unknown_entity); /* free method -> unknown */
642 * Analyse a Call address.
644 * @param node the node representing the call address
645 * @param methods after call contains the set of all possibly called entities
647 static void callee_ana_node(ir_node *node, eset *methods)
651 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
652 /* Beware of recursion */
653 if (get_irn_link(node) == MARK) {
654 /* already visited */
657 set_irn_link(node, MARK);
659 switch (get_irn_opcode(node)) {
661 /* A direct address call. We tread this as an external
662 call and ignore it completely. */
663 eset_insert(methods, unknown_entity); /* free method -> unknown */
667 ir_entity *ent = get_SymConst_entity(node);
668 assert(ent && is_method_entity(ent));
669 eset_insert(methods, ent);
674 /* polymorphic method */
675 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
676 ir_entity *ent = get_Sel_method(node, i);
678 eset_insert(methods, ent);
680 eset_insert(methods, unknown_entity);
690 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
691 callee_ana_node(get_Phi_pred(node, i), methods);
696 callee_ana_node(get_Mux_false(node), methods);
697 callee_ana_node(get_Mux_true(node), methods);
701 callee_ana_node(get_Id_pred(node), methods);
705 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
712 eset_insert(methods, unknown_entity); /* free method -> unknown */
716 assert(0 && "invalid opcode or opcode not implemented");
722 * Walker: Analyses every Call node and calculates an array of possible
723 * callees for that call.
725 static void callee_walker(ir_node *call, void *env)
729 eset *methods = eset_create();
734 callee_ana_node(get_Call_ptr(call), methods);
735 arr = NEW_ARR_F(ir_entity *, eset_count(methods));
736 for (i = 0, ent = eset_first(methods); ent; ent = eset_next(methods)) {
738 /* we want the unknown_entity on the zero position for easy tests later */
739 if (ent == unknown_entity) {
741 arr[0] = unknown_entity;
745 set_Call_callee_arr(call, ARR_LEN(arr), arr);
747 eset_destroy(methods);
752 * Walker: Removes all tuple.
754 static void remove_Tuples(ir_node *proj, void *env)
758 if (! is_Proj(proj)) return;
760 nn = skip_Tuple(proj);
761 if (nn != proj) exchange(proj, nn);
766 * Determine for every Call the set of possibly called methods and stores it
767 * inside the Call (@see set_Call_callee()).
768 * Uses the sel_methods set with much be already calculated.
770 static void callee_ana(void)
773 /* analyse all graphs */
774 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
775 ir_graph *irg = get_irp_irg(i);
776 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
777 set_irg_callee_info_state(irg, irg_callee_info_consistent);
779 set_irp_callee_info_state(irg_callee_info_consistent);
782 /*--------------------------------------------------------------------------*/
783 /* Cleanup after analyses. */
784 /*--------------------------------------------------------------------------*/
786 /** Frees intermediate data structures. */
787 static void sel_methods_dispose(void)
791 for (ent = eset_first(entities); ent; ent = eset_next(entities)) {
792 ir_entity ** arr = get_entity_link(ent);
796 set_entity_link(ent, NULL);
798 eset_destroy(entities);
802 /*--------------------------------------------------------------------------*/
803 /* Freeing the callee arrays. */
804 /*--------------------------------------------------------------------------*/
806 static void destruct_walker(ir_node * node, void * env)
810 remove_Call_callee_arr(node);
814 /*--------------------------------------------------------------------------*/
816 /*--------------------------------------------------------------------------*/
818 void cgana(int *length, ir_entity ***free_methods)
820 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
822 *free_methods = get_free_methods(length);
824 sel_methods_dispose();
827 void free_callee_info(ir_graph *irg)
829 irg_walk_graph(irg, destruct_walker, NULL, NULL);
830 set_irg_callee_info_state(irg, irg_callee_info_none);
833 void free_irp_callee_info(void)
836 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
837 free_callee_info(get_irp_irg(i));
841 /* Optimize the address expressions passed to call nodes.
843 * This optimization performs the following transformations for
845 * - All SymConst operations that refer to intern methods are replaced
846 * by Const operations referring to the corresponding entity.
847 * - Sel nodes, that select entities that are not overwritten are
848 * replaced by Const nodes referring to the selected entity.
849 * - Sel nodes, for which no method exists at all are replaced by Bad
851 * - Sel nodes with a pointer input that is an Alloc node are replaced
852 * by Const nodes referring to the entity that implements the method in
853 * the type given by the Alloc node.
855 void opt_call_addrs(void)
858 sel_methods_dispose();