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.
54 #include "dbginfo_t.h"
55 #include "iropt_dbg.h"
64 /* unambiguous address used as a mark. */
65 static void *MARK = &MARK;
67 static eset *entities = NULL;
69 /*--------------------------------------------------------------------------*/
71 /*--------------------------------------------------------------------------*/
74 /*--------------------------------------------------------------------------*/
75 /* Initialize datastructures, remove unwanted constructs, optimize */
76 /* call target computations. */
77 /*--------------------------------------------------------------------------*/
79 /** Returns the entity that contains the implementation of the inherited
80 * entity if available, else returns the entity passed. */
81 static ir_entity *get_inherited_methods_implementation(ir_entity *inh_meth) {
82 ir_node *value = get_atomic_ent_value(inh_meth);
83 assert(value && "constant entity without value");
84 assert(is_SymConst_addr_ent(value) &&
85 "Complex constant values not supported -- address of method should be straight constant!");
87 return get_SymConst_entity(value);
90 /** Collect the entity representing the implementation of this
91 * method (not the same if inherited) and all entities for overwriting
92 * implementations in "set".
93 * If the implementation of the method is not included in the
94 * compilation unit "open" is set to true.
95 * A recursive descend in the overwritten relation.
96 * Cycle-free, therefore must terminate.
99 * @param set A set of entities.
100 * @param size Number of entities in set.
103 static void collect_impls(ir_entity *method, eset *set, int *size, int *open) {
107 /* Add the implementation to the set if it contains an irg, else
108 remember that there are more methods called. */
110 if (get_entity_peculiarity(method) == peculiarity_inherited)
111 impl = get_inherited_methods_implementation(method);
113 if (get_entity_peculiarity(method) != peculiarity_description) {
114 eset_insert(set, impl);
118 /*- recursive descent -*/
119 for (i = get_entity_n_overwrittenby(method) - 1; i >= 0; --i)
120 collect_impls(get_entity_overwrittenby(method, i), set, size, open);
123 /** Alle Methoden bestimmen, die die übergebene Methode überschreiben
124 * (und implementieren). In der zurückgegebenen Reihung kommt jede
125 * Methode nur einmal vor. Der Wert 'NULL' steht für unbekannte
126 * (externe) Methoden. Die zurückgegebene Reihung muß vom Aufrufer
127 * wieder freigegeben werden (siehe "DEL_ARR_F"). Gibt es überhaupt
128 * keine Methoden, die "method" überschreiben, so gibt die Methode
133 static ir_entity ** get_impl_methods(ir_entity * method) {
134 eset * set = eset_create();
139 /* Collect all method entities that can be called here */
140 collect_impls(method, set, &size, &open);
142 /* Vorgaenger einfuegen. */
143 if (size == 0 && !open) {
144 /* keine implementierte überschriebene Methode */
148 arr = NEW_ARR_F(ir_entity *, size + 1);
149 arr[0] = NULL; /* Represents open method */
150 for (ent = eset_first(set); size > 0; ent = eset_next(set), --size)
154 arr = NEW_ARR_F(ir_entity *, size);
155 for (size -= 1, ent = eset_first(set); size >= 0; ent = eset_next(set), --size)
162 /** Analyze address computations.
164 * Compute for all Sel nodes the set of methods that can be selected.
165 * For each entity we store the set of subentities in the link field.
167 * Further do some optimizations:
168 * - Call standard optimizations for Sel nodes: this removes polymorphic
170 * - If the node is a SymConst(name) replace it by SymConst(ent) if possible.
171 * For this we precomputed a map name->entity. Nowadays, we no more support
173 * - If the node is a Sel:
174 * If we found only a single method that can be called, replace the Sel
175 * by a SymConst. This is more powerful than the analysis in opt_polymorphy,
176 * as here we walk the type graph. In opt_polymorphy we only apply a local
179 * @param node The node to analyze
180 * @param env A map that maps names of entities to the entities.
182 static void sel_methods_walker(ir_node *node, void *env) {
183 pmap *ldname_map = env;
186 /* Call standard optimizations */
188 ir_node *new_node = optimize_in_place(node);
189 if (node != new_node) {
190 exchange(node, new_node);
195 /* replace SymConst(name)-operations by SymConst(ent) */
196 if (is_SymConst(node)) {
197 if (get_SymConst_kind(node) == symconst_addr_name) {
198 pmap_entry *entry = pmap_find(ldname_map, get_SymConst_name(node));
199 if (entry != NULL) { /* Method is declared in the compiled code */
200 assert(!"There should not be a SymConst[addr_name] addressing a method with an implementation"
201 "in this compilation unit. Use a SymConst[addr_ent].");
204 } else if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
205 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
206 assert(get_entity_peculiarity(ent) != peculiarity_inherited);
208 if (!eset_contains(entities, ent)) {
209 /* Entity not yet handled. Find all (internal or external)
210 * implemented methods that overwrites this entity.
211 * This set is stored in the entity link. */
212 set_entity_link(ent, get_impl_methods(ent));
213 eset_insert(entities, ent);
216 /* -- As an add on we get an optimization that removes polymorphic calls.
217 This optimization is more powerful than that in transform_node_Sel(). -- */
218 arr = get_entity_link(ent);
221 * The Sel node never returns a pointer to a usable method.
222 * We could not call it, but it may be description:
223 * We call a method in a dead part of the program.
225 assert(get_entity_peculiarity(ent) == peculiarity_description);
227 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
228 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
232 * The Sel node returns only one possible method.
233 * So we could replace the Sel node by a SymConst.
234 * This method must exists.
236 set_irg_current_block(current_ir_graph, get_nodes_block(node));
237 assert(get_entity_peculiarity(get_SymConst_entity(get_atomic_ent_value(arr[0]))) ==
238 peculiarity_existent);
239 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]));
240 DBG_OPT_POLY(node, new_node);
241 exchange(node, new_node);
247 * Initialize auxiliary data structures.
249 * Computes a set of entities that overwrite an entity and contain
250 * an implementation. The set is stored in the entity's link field.
252 * Further replaces Sel nodes where this set contains exactly one
253 * method by SymConst nodes.
254 * Finally asserts if there is a SymConst(name) if there could be a
257 static void sel_methods_init(void) {
259 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
260 SymConst(name) by SymConst(ent). */
261 assert(entities == NULL);
262 entities = eset_create();
263 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
264 ir_entity * ent = get_irg_entity(get_irp_irg(i));
265 /* only external visible methods are allowed to call by a SymConst_ptr_name */
266 if (get_entity_visibility(ent) != visibility_local) {
267 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
271 all_irg_walk(sel_methods_walker, NULL, ldname_map);
272 pmap_destroy(ldname_map);
275 /*--------------------------------------------------------------------------*/
276 /* Find free methods.
278 * We expect that each entity has an array with all implementations in its
280 /*--------------------------------------------------------------------------*/
283 * Returns an array of all methods that could be called at a Sel node.
284 * This array contains every entry only once.
286 * @param sel the Sel node
288 static ir_entity ** get_Sel_arr(ir_node * sel) {
289 static ir_entity ** NULL_ARRAY = NULL;
294 ent = get_Sel_entity(sel);
295 ent = get_inherited_methods_implementation(ent);
297 assert(is_Method_type(get_entity_type(ent))); /* what else? */
298 arr = get_entity_link(ent);
302 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
303 * kann für polymorphe (abstrakte) Methoden passieren. */
305 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
312 * Returns the number of possible called methods at a Sel node.
314 * @param sel the Sel node
316 static int get_Sel_n_methods(ir_node * sel) {
317 return ARR_LEN(get_Sel_arr(sel));
321 * Returns the ith possible called method entity at a Sel node.
323 static ir_entity * get_Sel_method(ir_node * sel, int pos) {
324 ir_entity ** arr = get_Sel_arr(sel);
325 assert(pos >= 0 && pos < ARR_LEN(arr));
330 static void free_mark(ir_node * node, eset * set);
332 static void free_mark_proj(ir_node * node, long n, eset * set) {
333 assert(get_irn_mode(node) == mode_T);
334 if (get_irn_link(node) == MARK) {
335 /* already visited */
338 set_irn_link(node, MARK);
339 switch (get_irn_opcode(node)) {
341 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
342 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
344 ir_node * pred = get_Proj_pred(node);
345 if (get_irn_link(pred) != MARK && is_Tuple(pred)) {
346 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
348 /* nothing: da in "free_ana_walker" behandelt. */
354 free_mark(get_Tuple_pred(node, n), set);
358 free_mark_proj(get_Id_pred(node), n, set);
364 /* nothing: Die Operationen werden in free_ana_walker() selbst
369 assert(0 && "unexpected opcode or opcode not implemented");
372 // set_irn_link(node, NULL);
376 * Called for predecessors nodes of "interesting" ones.
377 * Interesting ones include all nodes that can somehow make
380 * If a method (or a set of methods in case of polymorph calls) gets visible,
381 * add it to the set of 'free' methods
383 * @param node the current visited node
384 * @param set the set of all free methods
386 static void free_mark(ir_node *node, eset * set) {
389 if (get_irn_link(node) == MARK)
390 return; /* already visited */
392 set_irn_link(node, MARK);
394 switch (get_irn_opcode(node)) {
396 ir_entity *ent = get_Sel_entity(node);
397 if (is_method_entity(ent)) {
398 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
399 eset_insert(set, get_Sel_method(node, i));
405 if (get_SymConst_kind(node) == symconst_addr_ent) {
406 ir_entity *ent = get_SymConst_entity(node);
407 if (is_method_entity(ent)) {
408 eset_insert(set, ent);
411 assert(get_SymConst_kind(node) == symconst_addr_name);
412 /* nothing: SymConst points to extern method */
417 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
418 free_mark(get_Phi_pred(node, i), set);
422 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
431 * post-walker. Find method addresses.
433 static void free_ana_walker(ir_node *node, void *env) {
437 if (get_irn_link(node) == MARK) {
438 /* already visited */
441 switch (get_irn_opcode(node)) {
453 /* we must handle Call nodes specially, because their call address input
454 do not expose a method address. */
455 set_irn_link(node, MARK);
456 for (i = get_Call_n_params(node) - 1; i >= 0; --i) {
457 ir_node *pred = get_Call_param(node, i);
458 if (mode_is_reference(get_irn_mode(pred))) {
459 free_mark(pred, set);
464 /* other nodes: Alle anderen Knoten nehmen wir als Verräter an, bis
465 * jemand das Gegenteil implementiert. */
466 set_irn_link(node, MARK);
467 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
468 ir_node *pred = get_irn_n(node, i);
469 if (mode_is_reference(get_irn_mode(pred))) {
470 free_mark(pred, set);
478 * Add all method addresses in global new style initializers to the set.
481 * We do NOT check the type here, just it it's an entity address.
482 * The reason for this is code like:
484 * void *p = function;
486 * which is sometimes used to anchor functions.
488 static void add_method_address_inititializer(ir_initializer_t *initializer,
494 switch (initializer->kind) {
495 case IR_INITIALIZER_CONST:
496 n = initializer->consti.value;
498 /* let's check if it's the address of a function */
500 ir_entity *ent = get_Global_entity(n);
502 if (is_Method_type(get_entity_type(ent)))
503 eset_insert(set, ent);
506 case IR_INITIALIZER_TARVAL:
507 case IR_INITIALIZER_NULL:
509 case IR_INITIALIZER_COMPOUND:
510 for (i = 0; i < initializer->compound.n_initializers; ++i) {
511 ir_initializer_t *sub_initializer
512 = initializer->compound.initializers[i];
513 add_method_address_inititializer(sub_initializer, set);
517 panic("invalid initializer found");
521 * Add all method addresses in global initializers to the set.
524 * We do NOT check the type here, just it it's an entity address.
525 * The reason for this is code like:
527 * void *p = function;
529 * which is sometimes used to anchor functions.
531 static void add_method_address(ir_entity *ent, eset *set)
537 /* do not check uninitialized values */
538 if (get_entity_variability(ent) == variability_uninitialized)
541 if (ent->has_initializer) {
542 add_method_address_inititializer(get_entity_initializer(ent), set);
543 } else if (is_atomic_entity(ent)) {
544 tp = get_entity_type(ent);
546 /* ignore methods: these of course reference it's address */
547 if (is_Method_type(tp))
550 /* let's check if it's the address of a function */
551 n = get_atomic_ent_value(ent);
553 ent = get_Global_entity(n);
555 if (is_Method_type(get_entity_type(ent)))
556 eset_insert(set, ent);
559 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
560 n = get_compound_ent_value(ent, i);
562 /* let's check if it's the address of a function */
564 ir_entity *ent = get_Global_entity(n);
566 if (is_Method_type(get_entity_type(ent)))
567 eset_insert(set, ent);
574 * returns a list of 'free' methods, i.e., the methods that can be called
575 * from external or via function pointers.
577 * Die Datenstrukturen für sel-Methoden (sel_methods) muß vor dem
578 * Aufruf von "get_free_methods" aufgebaut sein. Die (internen)
579 * SymConst(name)-Operationen müssen in passende SymConst(ent)-Operationen
580 * umgewandelt worden sein, d.h. SymConst-Operationen verweisen immer
581 * auf eine echt externe Methode.
583 static ir_entity **get_free_methods(int *length)
585 eset *free_set = eset_create();
592 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
593 irg = get_irp_irg(i);
594 ent = get_irg_entity(irg);
595 if (get_entity_visibility(ent) != visibility_local) {
596 /* insert non-local (external) methods. */
597 eset_insert(free_set, ent);
598 } else if (get_entity_stickyness(ent) == stickyness_sticky) {
599 /* insert "sticky" methods. */
600 eset_insert(free_set, ent);
603 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
604 /* Find all method entities that gets "visible" through this graphs,
605 * for instance because their address is stored. */
606 irg_walk_graph(irg, firm_clear_link, free_ana_walker, free_set);
607 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
610 /* insert all methods that are used in global variables initializers */
611 tp = get_glob_type();
612 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
613 ent = get_class_member(tp, i);
614 add_method_address(ent, free_set);
617 for (i = get_struct_n_members(tp) - 1; i >= 0; --i) {
618 ent = get_struct_member(tp, i);
619 add_method_address(ent, free_set);
622 /* the main program is even then "free", if it's not external visible. */
623 irg = get_irp_main_irg();
625 eset_insert(free_set, get_irg_entity(irg));
627 /* Finally, transform the set into an array. */
628 *length = eset_count(free_set);
629 arr = XMALLOCN(ir_entity*, *length);
630 for (i = 0, ent = eset_first(free_set); ent; ent = eset_next(free_set)) {
633 eset_destroy(free_set);
638 /*--------------------------------------------------------------------------*/
639 /* Callee analysis. */
640 /*--------------------------------------------------------------------------*/
642 static void callee_ana_node(ir_node * node, eset * methods);
644 static void callee_ana_proj(ir_node *node, long n, eset *methods) {
645 assert(get_irn_mode(node) == mode_T);
646 if (get_irn_link(node) == MARK) {
647 /* already visited */
650 set_irn_link(node, MARK);
652 switch (get_irn_opcode(node)) {
654 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
655 * op_Tuple oder ein Knoten, der eine "freie Methode"
657 ir_node *pred = get_Proj_pred(node);
658 if (get_irn_link(pred) != MARK) {
659 if (is_Tuple(pred)) {
660 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
662 eset_insert(methods, unknown_entity); /* free method -> unknown */
669 callee_ana_node(get_Tuple_pred(node, n), methods);
673 eset_insert(methods, unknown_entity); /* free method -> unknown */
679 * Analyse a Call address.
681 * @param node the node representing the call address
682 * @param methods after call contains the set of all possibly called entities
684 static void callee_ana_node(ir_node *node, eset *methods) {
687 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
688 /* Beware of recursion */
689 if (get_irn_link(node) == MARK) {
690 /* already visited */
693 set_irn_link(node, MARK);
695 switch (get_irn_opcode(node)) {
697 /* A direct address call. We tread this as an external
698 call and ignore it completely. */
699 eset_insert(methods, unknown_entity); /* free method -> unknown */
702 if (get_SymConst_kind(node) == symconst_addr_ent) {
703 ir_entity *ent = get_SymConst_entity(node);
704 assert(ent && is_method_entity(ent));
705 eset_insert(methods, ent);
707 assert(get_SymConst_kind(node) == symconst_addr_name);
708 /* external method (because fix_symconst()!) */
709 eset_insert(methods, unknown_entity); /* free method -> unknown */
713 /* polymorphic method */
714 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
715 ir_entity *ent = get_Sel_method(node, i);
717 eset_insert(methods, ent);
719 eset_insert(methods, unknown_entity);
729 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
730 callee_ana_node(get_Phi_pred(node, i), methods);
735 callee_ana_node(get_Mux_false(node), methods);
736 callee_ana_node(get_Mux_true(node), methods);
740 callee_ana_node(get_Id_pred(node), methods);
744 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
751 eset_insert(methods, unknown_entity); /* free method -> unknown */
755 assert(0 && "invalid opcode or opcode not implemented");
761 * Walker: Analyses every Call node and calculates an array of possible
762 * callees for that call.
764 static void callee_walker(ir_node *call, void *env) {
767 eset *methods = eset_create();
772 callee_ana_node(get_Call_ptr(call), methods);
773 arr = NEW_ARR_F(ir_entity *, eset_count(methods));
774 for (i = 0, ent = eset_first(methods); ent; ent = eset_next(methods)) {
776 /* we want the unknown_entity on the zero position for easy tests later */
777 if (ent == unknown_entity) {
779 arr[0] = unknown_entity;
783 set_Call_callee_arr(call, ARR_LEN(arr), arr);
785 eset_destroy(methods);
790 * Walker: Removes all tuple.
792 static void remove_Tuples(ir_node *proj, void *env) {
795 if (! is_Proj(proj)) return;
797 nn = skip_Tuple(proj);
798 if (nn != proj) exchange(proj, nn);
803 * Determine for every Call the set of possibly called methods and stores it
804 * inside the Call (@see set_Call_callee()).
805 * Uses the sel_methods set with much be already calculated.
807 static void callee_ana(void) {
809 /* analyse all graphs */
810 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
811 ir_graph *irg = get_irp_irg(i);
812 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
813 set_irg_callee_info_state(irg, irg_callee_info_consistent);
815 set_irp_callee_info_state(irg_callee_info_consistent);
818 /*--------------------------------------------------------------------------*/
819 /* Cleanup after analyses. */
820 /*--------------------------------------------------------------------------*/
822 /** Frees intermediate data structures. */
823 static void sel_methods_dispose(void) {
826 for (ent = eset_first(entities); ent; ent = eset_next(entities)) {
827 ir_entity ** arr = get_entity_link(ent);
831 set_entity_link(ent, NULL);
833 eset_destroy(entities);
837 /*--------------------------------------------------------------------------*/
838 /* Freeing the callee arrays. */
839 /*--------------------------------------------------------------------------*/
841 static void destruct_walker(ir_node * node, void * env) {
844 remove_Call_callee_arr(node);
848 /*--------------------------------------------------------------------------*/
850 /*--------------------------------------------------------------------------*/
852 void cgana(int *length, ir_entity ***free_methods) {
853 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
855 *free_methods = get_free_methods(length);
857 sel_methods_dispose();
860 void free_callee_info(ir_graph *irg) {
861 irg_walk_graph(irg, destruct_walker, NULL, NULL);
862 set_irg_callee_info_state(irg, irg_callee_info_none);
865 void free_irp_callee_info(void) {
867 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
868 free_callee_info(get_irp_irg(i));
872 /* Optimize the address expressions passed to call nodes.
874 * This optimization performs the following transformations for
876 * - All SymConst operations that refer to intern methods are replaced
877 * by Const operations referring to the corresponding entity.
878 * - Sel nodes, that select entities that are not overwritten are
879 * replaced by Const nodes referring to the selected entity.
880 * - Sel nodes, for which no method exists at all are replaced by Bad
882 * - Sel nodes with a pointer input that is an Alloc node are replaced
883 * by Const nodes referring to the entity that implements the method in
884 * the type given by the Alloc node.
886 void opt_call_addrs(void) {
888 sel_methods_dispose();