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.
56 #include "dbginfo_t.h"
57 #include "iropt_dbg.h"
70 /* unambiguous address used as a mark. */
71 static void *MARK = &MARK;
73 static eset *entities = NULL;
75 /*--------------------------------------------------------------------------*/
77 /*--------------------------------------------------------------------------*/
80 /*--------------------------------------------------------------------------*/
81 /* Initialize datastructures, remove unwanted constructs, optimize */
82 /* call target computations. */
83 /*--------------------------------------------------------------------------*/
85 /** Returns the entity that contains the implementation of the inherited
86 * entity if available, else returns the entity passed. */
87 static ir_entity *get_inherited_methods_implementation(ir_entity *inh_meth) {
88 ir_node *value = get_atomic_ent_value(inh_meth);
89 assert(value && "constant entity without value");
90 assert(is_SymConst_addr_ent(value) &&
91 "Complex constant values not supported -- address of method should be straight constant!");
93 return get_SymConst_entity(value);
96 /** Collect the entity representing the implementation of this
97 * method (not the same if inherited) and all entities for overwriting
98 * implementations in "set".
99 * If the implementation of the method is not included in the
100 * compilation unit "open" is set to true.
101 * A recursive descend in the overwritten relation.
102 * Cycle-free, therefore must terminate.
105 * @param set A set of entities.
106 * @param size Number of entities in set.
109 static void collect_impls(ir_entity *method, eset *set, int *size, int *open) {
113 /* Add the implementation to the set if it contains an irg, else
114 remember that there are more methods called. */
116 if (get_entity_peculiarity(method) == peculiarity_inherited)
117 impl = get_inherited_methods_implementation(method);
119 if (get_entity_peculiarity(method) != peculiarity_description) {
120 eset_insert(set, impl);
124 /*- recursive descent -*/
125 for (i = get_entity_n_overwrittenby(method) - 1; i >= 0; --i)
126 collect_impls(get_entity_overwrittenby(method, i), set, size, open);
129 /** Alle Methoden bestimmen, die die übergebene Methode überschreiben
130 * (und implementieren). In der zurückgegebenen Reihung kommt jede
131 * Methode nur einmal vor. Der Wert 'NULL' steht für unbekannte
132 * (externe) Methoden. Die zurückgegebene Reihung muß vom Aufrufer
133 * wieder freigegeben werden (siehe "DEL_ARR_F"). Gibt es überhaupt
134 * keine Methoden, die "method" überschreiben, so gibt die Methode
139 static ir_entity ** get_impl_methods(ir_entity * method) {
140 eset * set = eset_create();
145 /* Collect all method entities that can be called here */
146 collect_impls(method, set, &size, &open);
148 /* Vorgaenger einfuegen. */
149 if (size == 0 && !open) {
150 /* keine implementierte überschriebene Methode */
154 arr = NEW_ARR_F(ir_entity *, size + 1);
155 arr[0] = NULL; /* Represents open method */
156 for (ent = eset_first(set); size > 0; ent = eset_next(set), --size)
160 arr = NEW_ARR_F(ir_entity *, size);
161 for (size -= 1, ent = eset_first(set); size >= 0; ent = eset_next(set), --size)
168 /** Analyze address computations.
170 * Compute for all Sel nodes the set of methods that can be selected.
171 * For each entity we store the set of subentities in the link field.
173 * Further do some optimizations:
174 * - Call standard optimizations for Sel nodes: this removes polymorphic
176 * - If the node is a SymConst(name) replace it by SymConst(ent) if possible.
177 * For this we precomputed a map name->entity. Nowadays, we no more support
179 * - If the node is a Sel:
180 * If we found only a single method that can be called, replace the Sel
181 * by a SymConst. This is more powerful than the analysis in opt_polymorphy,
182 * as here we walk the type graph. In opt_polymorphy we only apply a local
185 * @param node The node to analyze
186 * @param env A map that maps names of entities to the entities.
188 static void sel_methods_walker(ir_node *node, void *env) {
189 pmap *ldname_map = env;
192 /* Call standard optimizations */
194 ir_node *new_node = optimize_in_place(node);
195 if (node != new_node) {
196 exchange(node, new_node);
201 /* replace SymConst(name)-operations by SymConst(ent) */
202 if (is_SymConst(node)) {
203 if (get_SymConst_kind(node) == symconst_addr_name) {
204 pmap_entry *entry = pmap_find(ldname_map, get_SymConst_name(node));
205 if (entry != NULL) { /* Method is declared in the compiled code */
206 assert(!"There should not be a SymConst[addr_name] addressing a method with an implementation"
207 "in this compilation unit. Use a SymConst[addr_ent].");
210 } else if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
211 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
212 assert(get_entity_peculiarity(ent) != peculiarity_inherited);
214 if (!eset_contains(entities, ent)) {
215 /* Entity not yet handled. Find all (internal or external)
216 * implemented methods that overwrites this entity.
217 * This set is stored in the entity link. */
218 set_entity_link(ent, get_impl_methods(ent));
219 eset_insert(entities, ent);
222 /* -- As an add on we get an optimization that removes polymorphic calls.
223 This optimization is more powerful than that in transform_node_Sel(). -- */
224 arr = get_entity_link(ent);
227 * The Sel node never returns a pointer to a usable method.
228 * We could not call it, but it may be description:
229 * We call a method in a dead part of the program.
231 assert(get_entity_peculiarity(ent) == peculiarity_description);
233 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
234 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
238 * The Sel node returns only one possible method.
239 * So we could replace the Sel node by a SymConst.
240 * This method must exists.
242 set_irg_current_block(current_ir_graph, get_nodes_block(node));
243 assert(get_entity_peculiarity(get_SymConst_entity(get_atomic_ent_value(arr[0]))) ==
244 peculiarity_existent);
245 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]));
246 DBG_OPT_POLY(node, new_node);
247 exchange(node, new_node);
253 * Initialize auxiliary data structures.
255 * Computes a set of entities that overwrite an entity and contain
256 * an implementation. The set is stored in the entity's link field.
258 * Further replaces Sel nodes where this set contains exactly one
259 * method by SymConst nodes.
260 * Finally asserts if there is a SymConst(name) if there could be a
263 static void sel_methods_init(void) {
265 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
266 SymConst(name) by SymConst(ent). */
267 assert(entities == NULL);
268 entities = eset_create();
269 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
270 ir_entity * ent = get_irg_entity(get_irp_irg(i));
271 /* only external visible methods are allowed to call by a SymConst_ptr_name */
272 if (get_entity_visibility(ent) != visibility_local) {
273 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
277 all_irg_walk(sel_methods_walker, NULL, ldname_map);
278 pmap_destroy(ldname_map);
281 /*--------------------------------------------------------------------------*/
282 /* Find free methods.
284 * We expect that each entity has an array with all implementations in its
286 /*--------------------------------------------------------------------------*/
289 * Returns an array of all methods that could be called at a Sel node.
290 * This array contains every entry only once.
292 * @param sel the Sel node
294 static ir_entity ** get_Sel_arr(ir_node * sel) {
295 static ir_entity ** NULL_ARRAY = NULL;
300 ent = get_Sel_entity(sel);
301 ent = get_inherited_methods_implementation(ent);
303 assert(is_Method_type(get_entity_type(ent))); /* what else? */
304 arr = get_entity_link(ent);
308 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
309 * kann für polymorphe (abstrakte) Methoden passieren. */
311 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
318 * Returns the number of possible called methods at a Sel node.
320 * @param sel the Sel node
322 static int get_Sel_n_methods(ir_node * sel) {
323 return ARR_LEN(get_Sel_arr(sel));
327 * Returns the ith possible called method entity at a Sel node.
329 static ir_entity * get_Sel_method(ir_node * sel, int pos) {
330 ir_entity ** arr = get_Sel_arr(sel);
331 assert(pos >= 0 && pos < ARR_LEN(arr));
336 static void free_mark(ir_node * node, eset * set);
338 static void free_mark_proj(ir_node * node, long n, eset * set) {
339 assert(get_irn_mode(node) == mode_T);
340 if (get_irn_link(node) == MARK) {
341 /* already visited */
344 set_irn_link(node, MARK);
345 switch (get_irn_opcode(node)) {
347 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
348 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
350 ir_node * pred = get_Proj_pred(node);
351 if (get_irn_link(pred) != MARK && get_irn_op(pred) == op_Tuple) {
352 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
354 /* nothing: da in "free_ana_walker" behandelt. */
360 free_mark(get_Tuple_pred(node, n), set);
364 free_mark_proj(get_Id_pred(node), n, set);
370 /* nothing: Die Operationen werden in free_ana_walker() selbst
375 assert(0 && "unexpected opcode or opcode not implemented");
378 // set_irn_link(node, NULL);
382 * Called for predecessors nodes of "interesting" ones.
383 * Interesting ones include all nodes that can somehow make
386 * If a method (or a set of methods in case of polymorph calls) gets visible,
387 * add it to the set of 'free' methods
389 * @param node the current visited node
390 * @param set the set of all free methods
392 static void free_mark(ir_node *node, eset * set) {
395 if (get_irn_link(node) == MARK)
396 return; /* already visited */
398 set_irn_link(node, MARK);
400 switch (get_irn_opcode(node)) {
402 ir_entity *ent = get_Sel_entity(node);
403 if (is_method_entity(ent)) {
404 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
405 eset_insert(set, get_Sel_method(node, i));
411 if (get_SymConst_kind(node) == symconst_addr_ent) {
412 ir_entity *ent = get_SymConst_entity(node);
413 if (is_method_entity(ent)) {
414 eset_insert(set, ent);
417 assert(get_SymConst_kind(node) == symconst_addr_name);
418 /* nothing: SymConst points to extern method */
423 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
424 free_mark(get_Phi_pred(node, i), set);
428 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
437 * post-walker. Find method addresses.
439 static void free_ana_walker(ir_node *node, void *env) {
443 if (get_irn_link(node) == MARK) {
444 /* already visited */
447 switch (get_irn_opcode(node)) {
459 /* we must handle Call nodes specially, because their call address input
460 do not expose a method address. */
461 set_irn_link(node, MARK);
462 for (i = get_Call_n_params(node) - 1; i >= 0; --i) {
463 ir_node *pred = get_Call_param(node, i);
464 if (mode_is_reference(get_irn_mode(pred))) {
465 free_mark(pred, set);
470 /* other nodes: Alle anderen Knoten nehmen wir als Verräter an, bis
471 * jemand das Gegenteil implementiert. */
472 set_irn_link(node, MARK);
473 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
474 ir_node *pred = get_irn_n(node, i);
475 if (mode_is_reference(get_irn_mode(pred))) {
476 free_mark(pred, set);
484 * Add all method addresses in global new style initializers to the set.
487 * We do NOT check the type here, just it it's an entity address.
488 * The reason for this is code like:
490 * void *p = function;
492 * which is sometimes used to anchor functions.
494 static void add_method_address_inititializer(ir_initializer_t *initializer,
500 switch (initializer->kind) {
501 case IR_INITIALIZER_CONST:
502 n = initializer->consti.value;
504 /* let's check if it's the address of a function */
506 ir_entity *ent = get_Global_entity(n);
508 if (is_Method_type(get_entity_type(ent)))
509 eset_insert(set, ent);
512 case IR_INITIALIZER_TARVAL:
513 case IR_INITIALIZER_NULL:
515 case IR_INITIALIZER_COMPOUND:
516 for (i = 0; i < initializer->compound.n_initializers; ++i) {
517 ir_initializer_t *sub_initializer
518 = initializer->compound.initializers[i];
519 add_method_address_inititializer(sub_initializer, set);
523 panic("invalid initializer found");
527 * Add all method addresses in global initializers to the set.
530 * We do NOT check the type here, just it it's an entity address.
531 * The reason for this is code like:
533 * void *p = function;
535 * which is sometimes used to anchor functions.
537 static void add_method_address(ir_entity *ent, eset *set)
543 /* do not check uninitialized values */
544 if (get_entity_variability(ent) == variability_uninitialized)
547 if (ent->has_initializer) {
548 add_method_address_inititializer(get_entity_initializer(ent), set);
549 } else if (is_atomic_entity(ent)) {
550 tp = get_entity_type(ent);
552 /* ignore methods: these of course reference it's address */
553 if (is_Method_type(tp))
556 /* let's check if it's the address of a function */
557 n = get_atomic_ent_value(ent);
559 ent = get_Global_entity(n);
561 if (is_Method_type(get_entity_type(ent)))
562 eset_insert(set, ent);
565 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
566 n = get_compound_ent_value(ent, i);
568 /* let's check if it's the address of a function */
570 ir_entity *ent = get_Global_entity(n);
572 if (is_Method_type(get_entity_type(ent)))
573 eset_insert(set, ent);
580 * returns a list of 'free' methods, i.e., the methods that can be called
581 * from external or via function pointers.
583 * Die Datenstrukturen für sel-Methoden (sel_methods) muß vor dem
584 * Aufruf von "get_free_methods" aufgebaut sein. Die (internen)
585 * SymConst(name)-Operationen müssen in passende SymConst(ent)-Operationen
586 * umgewandelt worden sein, d.h. SymConst-Operationen verweisen immer
587 * auf eine echt externe Methode.
589 static ir_entity **get_free_methods(int *length)
591 eset *free_set = eset_create();
598 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
599 irg = get_irp_irg(i);
600 ent = get_irg_entity(irg);
601 if (get_entity_visibility(ent) != visibility_local) {
602 /* insert non-local (external) methods. */
603 eset_insert(free_set, ent);
604 } else if (get_entity_stickyness(ent) == stickyness_sticky) {
605 /* insert "sticky" methods. */
606 eset_insert(free_set, ent);
609 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
610 /* Find all method entities that gets "visible" through this graphs,
611 * for instance because their address is stored. */
612 irg_walk_graph(irg, firm_clear_link, free_ana_walker, free_set);
613 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
616 /* insert all methods that are used in global variables initializers */
617 tp = get_glob_type();
618 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
619 ent = get_class_member(tp, i);
620 add_method_address(ent, free_set);
623 for (i = get_struct_n_members(tp) - 1; i >= 0; --i) {
624 ent = get_struct_member(tp, i);
625 add_method_address(ent, free_set);
628 /* the main program is even then "free", if it's not external visible. */
629 irg = get_irp_main_irg();
631 eset_insert(free_set, get_irg_entity(irg));
633 /* Finally, transform the set into an array. */
634 *length = eset_count(free_set);
635 arr = xmalloc(sizeof(ir_entity *) * (*length));
636 for (i = 0, ent = eset_first(free_set); ent; ent = eset_next(free_set)) {
639 eset_destroy(free_set);
644 /*--------------------------------------------------------------------------*/
645 /* Callee analysis. */
646 /*--------------------------------------------------------------------------*/
648 static void callee_ana_node(ir_node * node, eset * methods);
650 static void callee_ana_proj(ir_node *node, long n, eset *methods) {
651 assert(get_irn_mode(node) == mode_T);
652 if (get_irn_link(node) == MARK) {
653 /* already visited */
656 set_irn_link(node, MARK);
658 switch (get_irn_opcode(node)) {
660 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
661 * op_Tuple oder ein Knoten, der eine "freie Methode"
663 ir_node *pred = get_Proj_pred(node);
664 if (get_irn_link(pred) != MARK) {
665 if (is_Tuple(pred)) {
666 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
668 eset_insert(methods, unknown_entity); /* free method -> unknown */
675 callee_ana_node(get_Tuple_pred(node, n), methods);
679 eset_insert(methods, unknown_entity); /* free method -> unknown */
685 * Analyse a Call address.
687 * @param node the node representing the call address
688 * @param methods after call contains the set of all possibly called entities
690 static void callee_ana_node(ir_node *node, eset *methods) {
693 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
694 /* Beware of recursion */
695 if (get_irn_link(node) == MARK) {
696 /* already visited */
699 set_irn_link(node, MARK);
701 switch (get_irn_opcode(node)) {
703 /* A direct address call. We tread this as an external
704 call and ignore it completely. */
705 eset_insert(methods, unknown_entity); /* free method -> unknown */
708 if (get_SymConst_kind(node) == symconst_addr_ent) {
709 ir_entity *ent = get_SymConst_entity(node);
710 assert(ent && is_method_entity(ent));
711 eset_insert(methods, ent);
713 assert(get_SymConst_kind(node) == symconst_addr_name);
714 /* external method (because fix_symconst()!) */
715 eset_insert(methods, unknown_entity); /* free method -> unknown */
719 /* polymorphic method */
720 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
721 ir_entity *ent = get_Sel_method(node, i);
723 eset_insert(methods, ent);
725 eset_insert(methods, unknown_entity);
735 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
736 callee_ana_node(get_Phi_pred(node, i), methods);
741 callee_ana_node(get_Mux_false(node), methods);
742 callee_ana_node(get_Mux_true(node), methods);
746 callee_ana_node(get_Id_pred(node), methods);
750 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
757 eset_insert(methods, unknown_entity); /* free method -> unknown */
761 assert(0 && "invalid opcode or opcode not implemented");
767 * Walker: Analyses every Call node and calculates an array of possible
768 * callees for that call.
770 static void callee_walker(ir_node *call, void *env) {
773 eset *methods = eset_create();
778 callee_ana_node(get_Call_ptr(call), methods);
779 arr = NEW_ARR_F(ir_entity *, eset_count(methods));
780 for (i = 0, ent = eset_first(methods); ent; ent = eset_next(methods)) {
782 /* we want the unknown_entity on the zero position for easy tests later */
783 if (ent == unknown_entity) {
785 arr[0] = unknown_entity;
789 set_Call_callee_arr(call, ARR_LEN(arr), arr);
791 eset_destroy(methods);
796 * Walker: Removes all tuple.
798 static void remove_Tuples(ir_node *proj, void *env) {
801 if (! is_Proj(proj)) return;
803 nn = skip_Tuple(proj);
804 if (nn != proj) exchange(proj, nn);
809 * Determine for every Call the set of possibly called methods and stores it
810 * inside the Call (@see set_Call_callee()).
811 * Uses the sel_methods set with much be already calculated.
813 static void callee_ana(void) {
815 /* analyse all graphs */
816 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
817 ir_graph *irg = get_irp_irg(i);
818 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
819 set_irg_callee_info_state(irg, irg_callee_info_consistent);
821 set_irp_callee_info_state(irg_callee_info_consistent);
824 /*--------------------------------------------------------------------------*/
825 /* Cleanup after analyses. */
826 /*--------------------------------------------------------------------------*/
828 /** Frees intermediate data structures. */
829 static void sel_methods_dispose(void) {
832 for (ent = eset_first(entities); ent; ent = eset_next(entities)) {
833 ir_entity ** arr = get_entity_link(ent);
837 set_entity_link(ent, NULL);
839 eset_destroy(entities);
843 /*--------------------------------------------------------------------------*/
844 /* Freeing the callee arrays. */
845 /*--------------------------------------------------------------------------*/
847 static void destruct_walker(ir_node * node, void * env) {
850 remove_Call_callee_arr(node);
854 /*--------------------------------------------------------------------------*/
856 /*--------------------------------------------------------------------------*/
858 void cgana(int *length, ir_entity ***free_methods) {
859 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
861 *free_methods = get_free_methods(length);
863 sel_methods_dispose();
866 void free_callee_info(ir_graph *irg) {
867 irg_walk_graph(irg, destruct_walker, NULL, NULL);
868 set_irg_callee_info_state(irg, irg_callee_info_none);
871 void free_irp_callee_info(void) {
873 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
874 free_callee_info(get_irp_irg(i));
878 /* Optimize the address expressions passed to call nodes.
880 * This optimization performs the following transformations for
882 * - All SymConst operations that refer to intern methods are replaced
883 * by Const operations referring to the corresponding entity.
884 * - Sel nodes, that select entities that are not overwritten are
885 * replaced by Const nodes referring to the selected entity.
886 * - Sel nodes, for which no method exists at all are replaced by Bad
888 * - Sel nodes with a pointer input that is an Alloc node are replaced
889 * by Const nodes referring to the entity that implements the method in
890 * the type given by the Alloc node.
892 void opt_call_addrs(void) {
894 sel_methods_dispose();