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 /** Returns the entity that contains the implementation of the inherited
78 * entity if available, else returns the entity passed. */
79 static ir_entity *get_inherited_methods_implementation(ir_entity *inh_meth) {
80 ir_node *value = get_atomic_ent_value(inh_meth);
81 assert(value && "constant entity without value");
82 assert(is_SymConst_addr_ent(value) &&
83 "Complex constant values not supported -- address of method should be straight constant!");
85 return get_SymConst_entity(value);
88 /** Collect the entity representing the implementation of this
89 * method (not the same if inherited) and all entities for overwriting
90 * implementations in "set".
91 * If the implementation of the method is not included in the
92 * compilation unit "open" is set to true.
93 * A recursive descend in the overwritten relation.
94 * Cycle-free, therefore must terminate.
97 * @param set A set of entities.
98 * @param size Number of entities in set.
101 static void collect_impls(ir_entity *method, eset *set, int *size, int *open) {
105 /* Add the implementation to the set if it contains an irg, else
106 remember that there are more methods called. */
108 if (get_entity_peculiarity(method) == peculiarity_inherited)
109 impl = get_inherited_methods_implementation(method);
111 if (get_entity_peculiarity(method) != peculiarity_description) {
112 eset_insert(set, impl);
116 /*- recursive descent -*/
117 for (i = get_entity_n_overwrittenby(method) - 1; i >= 0; --i)
118 collect_impls(get_entity_overwrittenby(method, i), set, size, open);
121 /** Alle Methoden bestimmen, die die übergebene Methode überschreiben
122 * (und implementieren). In der zurückgegebenen Reihung kommt jede
123 * Methode nur einmal vor. Der Wert 'NULL' steht für unbekannte
124 * (externe) Methoden. Die zurückgegebene Reihung muß vom Aufrufer
125 * wieder freigegeben werden (siehe "DEL_ARR_F"). Gibt es überhaupt
126 * keine Methoden, die "method" überschreiben, so gibt die Methode
131 static ir_entity ** get_impl_methods(ir_entity * method) {
132 eset * set = eset_create();
137 /* Collect all method entities that can be called here */
138 collect_impls(method, set, &size, &open);
140 /* Vorgaenger einfuegen. */
141 if (size == 0 && !open) {
142 /* keine implementierte überschriebene Methode */
146 arr = NEW_ARR_F(ir_entity *, size + 1);
147 arr[0] = NULL; /* Represents open method */
148 for (ent = eset_first(set); size > 0; ent = eset_next(set), --size)
152 arr = NEW_ARR_F(ir_entity *, size);
153 for (size -= 1, ent = eset_first(set); size >= 0; ent = eset_next(set), --size)
160 /** Analyze address computations.
162 * Compute for all Sel nodes the set of methods that can be selected.
163 * For each entity we store the set of subentities in the link field.
165 * Further do some optimizations:
166 * - Call standard optimizations for Sel nodes: this removes polymorphic
168 * - If the node is a SymConst(name) replace it by SymConst(ent) if possible.
169 * For this we precomputed a map name->entity. Nowadays, we no more support
171 * - If the node is a Sel:
172 * If we found only a single method that can be called, replace the Sel
173 * by a SymConst. This is more powerful than the analysis in opt_polymorphy,
174 * as here we walk the type graph. In opt_polymorphy we only apply a local
177 * @param node The node to analyze
178 * @param env A map that maps names of entities to the entities.
180 static void sel_methods_walker(ir_node *node, void *env) {
181 pmap *ldname_map = env;
184 /* Call standard optimizations */
186 ir_node *new_node = optimize_in_place(node);
187 if (node != new_node) {
188 exchange(node, new_node);
193 /* replace SymConst(name)-operations by SymConst(ent) */
194 if (is_SymConst(node)) {
195 if (get_SymConst_kind(node) == symconst_addr_name) {
196 pmap_entry *entry = pmap_find(ldname_map, get_SymConst_name(node));
197 if (entry != NULL) { /* Method is declared in the compiled code */
198 assert(!"There should not be a SymConst[addr_name] addressing a method with an implementation"
199 "in this compilation unit. Use a SymConst[addr_ent].");
202 } else if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
203 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
204 assert(get_entity_peculiarity(ent) != peculiarity_inherited);
206 if (!eset_contains(entities, ent)) {
207 /* Entity not yet handled. Find all (internal or external)
208 * implemented methods that overwrites this entity.
209 * This set is stored in the entity link. */
210 set_entity_link(ent, get_impl_methods(ent));
211 eset_insert(entities, ent);
214 /* -- As an add on we get an optimization that removes polymorphic calls.
215 This optimization is more powerful than that in transform_node_Sel(). -- */
216 arr = get_entity_link(ent);
219 * The Sel node never returns a pointer to a usable method.
220 * We could not call it, but it may be description:
221 * We call a method in a dead part of the program.
223 assert(get_entity_peculiarity(ent) == peculiarity_description);
225 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
226 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
230 * The Sel node returns only one possible method.
231 * So we could replace the Sel node by a SymConst.
232 * This method must exists.
234 set_irg_current_block(current_ir_graph, get_nodes_block(node));
235 assert(get_entity_peculiarity(get_SymConst_entity(get_atomic_ent_value(arr[0]))) ==
236 peculiarity_existent);
237 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]));
238 DBG_OPT_POLY(node, new_node);
239 exchange(node, new_node);
245 * Initialize auxiliary data structures.
247 * Computes a set of entities that overwrite an entity and contain
248 * an implementation. The set is stored in the entity's link field.
250 * Further replaces Sel nodes where this set contains exactly one
251 * method by SymConst nodes.
252 * Finally asserts if there is a SymConst(name) if there could be a
255 static void sel_methods_init(void) {
257 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
258 SymConst(name) by SymConst(ent). */
259 assert(entities == NULL);
260 entities = eset_create();
261 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
262 ir_entity * ent = get_irg_entity(get_irp_irg(i));
263 /* only external visible methods are allowed to call by a SymConst_ptr_name */
264 if (get_entity_visibility(ent) != visibility_local) {
265 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
269 all_irg_walk(sel_methods_walker, NULL, ldname_map);
270 pmap_destroy(ldname_map);
273 /*--------------------------------------------------------------------------*/
274 /* Find free methods.
276 * We expect that each entity has an array with all implementations in its
278 /*--------------------------------------------------------------------------*/
281 * Returns an array of all methods that could be called at a Sel node.
282 * This array contains every entry only once.
284 * @param sel the Sel node
286 static ir_entity ** get_Sel_arr(ir_node * sel) {
287 static ir_entity ** NULL_ARRAY = NULL;
292 ent = get_Sel_entity(sel);
293 ent = get_inherited_methods_implementation(ent);
295 assert(is_Method_type(get_entity_type(ent))); /* what else? */
296 arr = get_entity_link(ent);
300 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
301 * kann für polymorphe (abstrakte) Methoden passieren. */
303 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
310 * Returns the number of possible called methods at a Sel node.
312 * @param sel the Sel node
314 static int get_Sel_n_methods(ir_node * sel) {
315 return ARR_LEN(get_Sel_arr(sel));
319 * Returns the ith possible called method entity at a Sel node.
321 static ir_entity * get_Sel_method(ir_node * sel, int pos) {
322 ir_entity ** arr = get_Sel_arr(sel);
323 assert(pos >= 0 && pos < ARR_LEN(arr));
328 static void free_mark(ir_node * node, eset * set);
330 static void free_mark_proj(ir_node * node, long n, eset * set) {
331 assert(get_irn_mode(node) == mode_T);
332 if (get_irn_link(node) == MARK) {
333 /* already visited */
336 set_irn_link(node, MARK);
337 switch (get_irn_opcode(node)) {
339 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
340 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
342 ir_node * pred = get_Proj_pred(node);
343 if (get_irn_link(pred) != MARK && is_Tuple(pred)) {
344 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
346 /* nothing: da in "free_ana_walker" behandelt. */
352 free_mark(get_Tuple_pred(node, n), set);
356 free_mark_proj(get_Id_pred(node), n, set);
362 /* nothing: Die Operationen werden in free_ana_walker() selbst
367 assert(0 && "unexpected opcode or opcode not implemented");
370 // set_irn_link(node, NULL);
374 * Called for predecessors nodes of "interesting" ones.
375 * Interesting ones include all nodes that can somehow make
378 * If a method (or a set of methods in case of polymorph calls) gets visible,
379 * add it to the set of 'free' methods
381 * @param node the current visited node
382 * @param set the set of all free methods
384 static void free_mark(ir_node *node, eset * set) {
387 if (get_irn_link(node) == MARK)
388 return; /* already visited */
390 set_irn_link(node, MARK);
392 switch (get_irn_opcode(node)) {
394 ir_entity *ent = get_Sel_entity(node);
395 if (is_method_entity(ent)) {
396 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
397 eset_insert(set, get_Sel_method(node, i));
403 if (get_SymConst_kind(node) == symconst_addr_ent) {
404 ir_entity *ent = get_SymConst_entity(node);
405 if (is_method_entity(ent)) {
406 eset_insert(set, ent);
412 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
413 free_mark(get_Phi_pred(node, i), set);
417 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
426 * post-walker. Find method addresses.
428 static void free_ana_walker(ir_node *node, void *env) {
432 if (get_irn_link(node) == MARK) {
433 /* already visited */
436 switch (get_irn_opcode(node)) {
448 /* we must handle Call nodes specially, because their call address input
449 do not expose a method address. */
450 set_irn_link(node, MARK);
451 for (i = get_Call_n_params(node) - 1; i >= 0; --i) {
452 ir_node *pred = get_Call_param(node, i);
453 if (mode_is_reference(get_irn_mode(pred))) {
454 free_mark(pred, set);
459 /* other nodes: Alle anderen Knoten nehmen wir als Verräter an, bis
460 * jemand das Gegenteil implementiert. */
461 set_irn_link(node, MARK);
462 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
463 ir_node *pred = get_irn_n(node, i);
464 if (mode_is_reference(get_irn_mode(pred))) {
465 free_mark(pred, set);
473 * Add all method addresses in global new style initializers to the set.
476 * We do NOT check the type here, just it it's an entity address.
477 * The reason for this is code like:
479 * void *p = function;
481 * which is sometimes used to anchor functions.
483 static void add_method_address_inititializer(ir_initializer_t *initializer,
489 switch (initializer->kind) {
490 case IR_INITIALIZER_CONST:
491 n = initializer->consti.value;
493 /* let's check if it's the address of a function */
495 ir_entity *ent = get_Global_entity(n);
497 if (is_Method_type(get_entity_type(ent)))
498 eset_insert(set, ent);
501 case IR_INITIALIZER_TARVAL:
502 case IR_INITIALIZER_NULL:
504 case IR_INITIALIZER_COMPOUND:
505 for (i = 0; i < initializer->compound.n_initializers; ++i) {
506 ir_initializer_t *sub_initializer
507 = initializer->compound.initializers[i];
508 add_method_address_inititializer(sub_initializer, set);
512 panic("invalid initializer found");
516 * Add all method addresses in global initializers to the set.
519 * We do NOT check the type here, just it it's an entity address.
520 * The reason for this is code like:
522 * void *p = function;
524 * which is sometimes used to anchor functions.
526 static void add_method_address(ir_entity *ent, eset *set)
532 /* do not check uninitialized values */
533 if (get_entity_variability(ent) == variability_uninitialized)
536 if (ent->has_initializer) {
537 add_method_address_inititializer(get_entity_initializer(ent), set);
538 } else if (is_atomic_entity(ent)) {
539 tp = get_entity_type(ent);
541 /* ignore methods: these of course reference it's address */
542 if (is_Method_type(tp))
545 /* let's check if it's the address of a function */
546 n = get_atomic_ent_value(ent);
548 ent = get_Global_entity(n);
550 if (is_Method_type(get_entity_type(ent)))
551 eset_insert(set, ent);
554 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
555 n = get_compound_ent_value(ent, i);
557 /* let's check if it's the address of a function */
559 ir_entity *ent = get_Global_entity(n);
561 if (is_Method_type(get_entity_type(ent)))
562 eset_insert(set, ent);
569 * returns a list of 'free' methods, i.e., the methods that can be called
570 * from external or via function pointers.
572 * Die Datenstrukturen für sel-Methoden (sel_methods) muß vor dem
573 * Aufruf von "get_free_methods" aufgebaut sein. Die (internen)
574 * SymConst(name)-Operationen müssen in passende SymConst(ent)-Operationen
575 * umgewandelt worden sein, d.h. SymConst-Operationen verweisen immer
576 * auf eine echt externe Methode.
578 static ir_entity **get_free_methods(int *length)
580 eset *free_set = eset_create();
587 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
588 irg = get_irp_irg(i);
589 ent = get_irg_entity(irg);
590 if (get_entity_visibility(ent) != visibility_local) {
591 /* insert non-local (external) methods. */
592 eset_insert(free_set, ent);
593 } else if (get_entity_stickyness(ent) == stickyness_sticky) {
594 /* insert "sticky" methods. */
595 eset_insert(free_set, ent);
598 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
599 /* Find all method entities that gets "visible" through this graphs,
600 * for instance because their address is stored. */
601 irg_walk_graph(irg, firm_clear_link, free_ana_walker, free_set);
602 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
605 /* insert all methods that are used in global variables initializers */
606 tp = get_glob_type();
607 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
608 ent = get_class_member(tp, i);
609 add_method_address(ent, free_set);
612 for (i = get_struct_n_members(tp) - 1; i >= 0; --i) {
613 ent = get_struct_member(tp, i);
614 add_method_address(ent, free_set);
617 /* the main program is even then "free", if it's not external visible. */
618 irg = get_irp_main_irg();
620 eset_insert(free_set, get_irg_entity(irg));
622 /* Finally, transform the set into an array. */
623 *length = eset_count(free_set);
624 arr = XMALLOCN(ir_entity*, *length);
625 for (i = 0, ent = eset_first(free_set); ent; ent = eset_next(free_set)) {
628 eset_destroy(free_set);
633 /*--------------------------------------------------------------------------*/
634 /* Callee analysis. */
635 /*--------------------------------------------------------------------------*/
637 static void callee_ana_node(ir_node * node, eset * methods);
639 static void callee_ana_proj(ir_node *node, long n, eset *methods) {
640 assert(get_irn_mode(node) == mode_T);
641 if (get_irn_link(node) == MARK) {
642 /* already visited */
645 set_irn_link(node, MARK);
647 switch (get_irn_opcode(node)) {
649 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
650 * op_Tuple oder ein Knoten, der eine "freie Methode"
652 ir_node *pred = get_Proj_pred(node);
653 if (get_irn_link(pred) != MARK) {
654 if (is_Tuple(pred)) {
655 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
657 eset_insert(methods, unknown_entity); /* free method -> unknown */
664 callee_ana_node(get_Tuple_pred(node, n), methods);
668 eset_insert(methods, unknown_entity); /* free method -> unknown */
674 * Analyse a Call address.
676 * @param node the node representing the call address
677 * @param methods after call contains the set of all possibly called entities
679 static void callee_ana_node(ir_node *node, eset *methods) {
682 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
683 /* Beware of recursion */
684 if (get_irn_link(node) == MARK) {
685 /* already visited */
688 set_irn_link(node, MARK);
690 switch (get_irn_opcode(node)) {
692 /* A direct address call. We tread this as an external
693 call and ignore it completely. */
694 eset_insert(methods, unknown_entity); /* free method -> unknown */
697 if (get_SymConst_kind(node) == symconst_addr_ent) {
698 ir_entity *ent = get_SymConst_entity(node);
699 assert(ent && is_method_entity(ent));
700 eset_insert(methods, ent);
702 assert(get_SymConst_kind(node) == symconst_addr_name);
703 /* external method (because fix_symconst()!) */
704 eset_insert(methods, unknown_entity); /* free method -> unknown */
708 /* polymorphic method */
709 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
710 ir_entity *ent = get_Sel_method(node, i);
712 eset_insert(methods, ent);
714 eset_insert(methods, unknown_entity);
724 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
725 callee_ana_node(get_Phi_pred(node, i), methods);
730 callee_ana_node(get_Mux_false(node), methods);
731 callee_ana_node(get_Mux_true(node), methods);
735 callee_ana_node(get_Id_pred(node), methods);
739 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
746 eset_insert(methods, unknown_entity); /* free method -> unknown */
750 assert(0 && "invalid opcode or opcode not implemented");
756 * Walker: Analyses every Call node and calculates an array of possible
757 * callees for that call.
759 static void callee_walker(ir_node *call, void *env) {
762 eset *methods = eset_create();
767 callee_ana_node(get_Call_ptr(call), methods);
768 arr = NEW_ARR_F(ir_entity *, eset_count(methods));
769 for (i = 0, ent = eset_first(methods); ent; ent = eset_next(methods)) {
771 /* we want the unknown_entity on the zero position for easy tests later */
772 if (ent == unknown_entity) {
774 arr[0] = unknown_entity;
778 set_Call_callee_arr(call, ARR_LEN(arr), arr);
780 eset_destroy(methods);
785 * Walker: Removes all tuple.
787 static void remove_Tuples(ir_node *proj, void *env) {
790 if (! is_Proj(proj)) return;
792 nn = skip_Tuple(proj);
793 if (nn != proj) exchange(proj, nn);
798 * Determine for every Call the set of possibly called methods and stores it
799 * inside the Call (@see set_Call_callee()).
800 * Uses the sel_methods set with much be already calculated.
802 static void callee_ana(void) {
804 /* analyse all graphs */
805 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
806 ir_graph *irg = get_irp_irg(i);
807 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
808 set_irg_callee_info_state(irg, irg_callee_info_consistent);
810 set_irp_callee_info_state(irg_callee_info_consistent);
813 /*--------------------------------------------------------------------------*/
814 /* Cleanup after analyses. */
815 /*--------------------------------------------------------------------------*/
817 /** Frees intermediate data structures. */
818 static void sel_methods_dispose(void) {
821 for (ent = eset_first(entities); ent; ent = eset_next(entities)) {
822 ir_entity ** arr = get_entity_link(ent);
826 set_entity_link(ent, NULL);
828 eset_destroy(entities);
832 /*--------------------------------------------------------------------------*/
833 /* Freeing the callee arrays. */
834 /*--------------------------------------------------------------------------*/
836 static void destruct_walker(ir_node * node, void * env) {
839 remove_Call_callee_arr(node);
843 /*--------------------------------------------------------------------------*/
845 /*--------------------------------------------------------------------------*/
847 void cgana(int *length, ir_entity ***free_methods) {
848 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
850 *free_methods = get_free_methods(length);
852 sel_methods_dispose();
855 void free_callee_info(ir_graph *irg) {
856 irg_walk_graph(irg, destruct_walker, NULL, NULL);
857 set_irg_callee_info_state(irg, irg_callee_info_none);
860 void free_irp_callee_info(void) {
862 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
863 free_callee_info(get_irp_irg(i));
867 /* Optimize the address expressions passed to call nodes.
869 * This optimization performs the following transformations for
871 * - All SymConst operations that refer to intern methods are replaced
872 * by Const operations referring to the corresponding entity.
873 * - Sel nodes, that select entities that are not overwritten are
874 * replaced by Const nodes referring to the selected entity.
875 * - Sel nodes, for which no method exists at all are replaced by Bad
877 * - Sel nodes with a pointer input that is an Alloc node are replaced
878 * by Const nodes referring to the entity that implements the method in
879 * the type given by the Alloc node.
881 void opt_call_addrs(void) {
883 sel_methods_dispose();