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.
55 #include "dbginfo_t.h"
56 #include "iropt_dbg.h"
69 /* unambiguous address used as a mark. */
70 static void *MARK = &MARK;
72 static eset *entities = NULL;
74 /*--------------------------------------------------------------------------*/
76 /*--------------------------------------------------------------------------*/
79 /*--------------------------------------------------------------------------*/
80 /* Initialize datastructures, remove unwanted constructs, optimize */
81 /* call target computations. */
82 /*--------------------------------------------------------------------------*/
84 /** Returns the entity that contains the implementation of the inherited
85 * entity if available, else returns the entity passed. */
86 static ir_entity *get_inherited_methods_implementation(ir_entity *inh_meth) {
87 ir_node *value = get_atomic_ent_value(inh_meth);
88 assert(value && "constant entity without value");
89 assert(is_SymConst_addr_ent(value) &&
90 "Complex constant values not supported -- address of method should be straight constant!");
92 return get_SymConst_entity(value);
95 /** Collect the entity representing the implementation of this
96 * method (not the same if inherited) and all entities for overwriting
97 * implementations in "set".
98 * If the implementation of the method is not included in the
99 * compilation unit "open" is set to true.
100 * A recursive descend in the overwritten relation.
101 * Cycle-free, therefore must terminate.
104 * @param set A set of entities.
105 * @param size Number of entities in set.
108 static void collect_impls(ir_entity *method, eset *set, int *size, int *open) {
112 /* Add the implementation to the set if it contains an irg, else
113 remember that there are more methods called. */
115 if (get_entity_peculiarity(method) == peculiarity_inherited)
116 impl = get_inherited_methods_implementation(method);
118 if (get_entity_peculiarity(method) != peculiarity_description) {
119 eset_insert(set, impl);
123 /*- recursive descent -*/
124 for (i = get_entity_n_overwrittenby(method) - 1; i >= 0; --i)
125 collect_impls(get_entity_overwrittenby(method, i), set, size, open);
128 /** Alle Methoden bestimmen, die die übergebene Methode überschreiben
129 * (und implementieren). In der zurückgegebenen Reihung kommt jede
130 * Methode nur einmal vor. Der Wert 'NULL' steht für unbekannte
131 * (externe) Methoden. Die zurückgegebene Reihung muß vom Aufrufer
132 * wieder freigegeben werden (siehe "DEL_ARR_F"). Gibt es überhaupt
133 * keine Methoden, die "method" überschreiben, so gibt die Methode
138 static ir_entity ** get_impl_methods(ir_entity * method) {
139 eset * set = eset_create();
144 /* Collect all method entities that can be called here */
145 collect_impls(method, set, &size, &open);
147 /* Vorgaenger einfuegen. */
148 if (size == 0 && !open) {
149 /* keine implementierte überschriebene Methode */
153 arr = NEW_ARR_F(ir_entity *, size + 1);
154 arr[0] = NULL; /* Represents open method */
155 for (ent = eset_first(set); size > 0; ent = eset_next(set), --size)
159 arr = NEW_ARR_F(ir_entity *, size);
160 for (size -= 1, ent = eset_first(set); size >= 0; ent = eset_next(set), --size)
167 /** Analyze address computations.
169 * Compute for all Sel nodes the set of methods that can be selected.
170 * For each entity we store the set of subentities in the link field.
172 * Further do some optimizations:
173 * - Call standard optimizations for Sel nodes: this removes polymorphic
175 * - If the node is a SymConst(name) replace it by SymConst(ent) if possible.
176 * For this we precomputed a map name->entity. Nowadays, we no more support
178 * - If the node is a Sel:
179 * If we found only a single method that can be called, replace the Sel
180 * by a SymConst. This is more powerful than the analysis in opt_polymorphy,
181 * as here we walk the type graph. In opt_polymorphy we only apply a local
184 * @param node The node to analyze
185 * @param env A map that maps names of entities to the entities.
187 static void sel_methods_walker(ir_node *node, void *env) {
188 pmap *ldname_map = env;
191 /* Call standard optimizations */
193 ir_node *new_node = optimize_in_place(node);
194 if (node != new_node) {
195 exchange(node, new_node);
200 /* replace SymConst(name)-operations by SymConst(ent) */
201 if (is_SymConst(node)) {
202 if (get_SymConst_kind(node) == symconst_addr_name) {
203 pmap_entry *entry = pmap_find(ldname_map, get_SymConst_name(node));
204 if (entry != NULL) { /* Method is declared in the compiled code */
205 assert(!"There should not be a SymConst[addr_name] addressing a method with an implementation"
206 "in this compilation unit. Use a SymConst[addr_ent].");
209 } else if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
210 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
211 assert(get_entity_peculiarity(ent) != peculiarity_inherited);
213 if (!eset_contains(entities, ent)) {
214 /* Entity not yet handled. Find all (internal or external)
215 * implemented methods that overwrites this entity.
216 * This set is stored in the entity link. */
217 set_entity_link(ent, get_impl_methods(ent));
218 eset_insert(entities, ent);
221 /* -- As an add on we get an optimization that removes polymorphic calls.
222 This optimization is more powerful than that in transform_node_Sel(). -- */
223 arr = get_entity_link(ent);
226 * The Sel node never returns a pointer to a usable method.
227 * We could not call it, but it may be description:
228 * We call a method in a dead part of the program.
230 assert(get_entity_peculiarity(ent) == peculiarity_description);
232 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
233 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
237 * The Sel node returns only one possible method.
238 * So we could replace the Sel node by a SymConst.
239 * This method must exists.
241 set_irg_current_block(current_ir_graph, get_nodes_block(node));
242 assert(get_entity_peculiarity(get_SymConst_entity(get_atomic_ent_value(arr[0]))) ==
243 peculiarity_existent);
244 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]));
245 DBG_OPT_POLY(node, new_node);
246 exchange(node, new_node);
252 * Initialize auxiliary data structures.
254 * Computes a set of entities that overwrite an entity and contain
255 * an implementation. The set is stored in the entity's link field.
257 * Further replaces Sel nodes where this set contains exactly one
258 * method by SymConst nodes.
259 * Finally asserts if there is a SymConst(name) if there could be a
262 static void sel_methods_init(void) {
264 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
265 SymConst(name) by SymConst(ent). */
266 assert(entities == NULL);
267 entities = eset_create();
268 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
269 ir_entity * ent = get_irg_entity(get_irp_irg(i));
270 /* only external visible methods are allowed to call by a SymConst_ptr_name */
271 if (get_entity_visibility(ent) != visibility_local) {
272 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
276 all_irg_walk(sel_methods_walker, NULL, ldname_map);
277 pmap_destroy(ldname_map);
280 /*--------------------------------------------------------------------------*/
281 /* Find free methods.
283 * We expect that each entity has an array with all implementations in its
285 /*--------------------------------------------------------------------------*/
288 * Returns an array of all methods that could be called at a Sel node.
289 * This array contains every entry only once.
291 * @param sel the Sel node
293 static ir_entity ** get_Sel_arr(ir_node * sel) {
294 static ir_entity ** NULL_ARRAY = NULL;
299 ent = get_Sel_entity(sel);
300 ent = get_inherited_methods_implementation(ent);
302 assert(is_Method_type(get_entity_type(ent))); /* what else? */
303 arr = get_entity_link(ent);
307 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
308 * kann für polymorphe (abstrakte) Methoden passieren. */
310 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
317 * Returns the number of possible called methods at a Sel node.
319 * @param sel the Sel node
321 static int get_Sel_n_methods(ir_node * sel) {
322 return ARR_LEN(get_Sel_arr(sel));
326 * Returns the ith possible called method entity at a Sel node.
328 static ir_entity * get_Sel_method(ir_node * sel, int pos) {
329 ir_entity ** arr = get_Sel_arr(sel);
330 assert(pos >= 0 && pos < ARR_LEN(arr));
335 static void free_mark(ir_node * node, eset * set);
337 static void free_mark_proj(ir_node * node, long n, eset * set) {
338 assert(get_irn_mode(node) == mode_T);
339 if (get_irn_link(node) == MARK) {
340 /* already visited */
343 set_irn_link(node, MARK);
344 switch (get_irn_opcode(node)) {
346 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
347 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
349 ir_node * pred = get_Proj_pred(node);
350 if (get_irn_link(pred) != MARK && get_irn_op(pred) == op_Tuple) {
351 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
353 /* nothing: da in "free_ana_walker" behandelt. */
359 free_mark(get_Tuple_pred(node, n), set);
363 free_mark_proj(get_Id_pred(node), n, set);
369 /* nothing: Die Operationen werden in free_ana_walker() selbst
374 assert(0 && "unexpected opcode or opcode not implemented");
377 // set_irn_link(node, NULL);
381 * Called for predecessors nodes of "interesting" ones.
382 * Interesting ones include all nodes that can somehow make
385 * If a method (or a set of methods in case of polymorph calls) gets visible,
386 * add it to the set of 'free' methods
388 * @param node the current visited node
389 * @param set the set of all free methods
391 static void free_mark(ir_node *node, eset * set) {
394 if (get_irn_link(node) == MARK)
395 return; /* already visited */
397 set_irn_link(node, MARK);
399 switch (get_irn_opcode(node)) {
401 ir_entity *ent = get_Sel_entity(node);
402 if (is_method_entity(ent)) {
403 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
404 eset_insert(set, get_Sel_method(node, i));
410 if (get_SymConst_kind(node) == symconst_addr_ent) {
411 ir_entity *ent = get_SymConst_entity(node);
412 if (is_method_entity(ent)) {
413 eset_insert(set, ent);
416 assert(get_SymConst_kind(node) == symconst_addr_name);
417 /* nothing: SymConst points to extern method */
422 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
423 free_mark(get_Phi_pred(node, i), set);
427 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
436 * post-walker. Find method addresses.
438 static void free_ana_walker(ir_node *node, void *env) {
442 if (get_irn_link(node) == MARK) {
443 /* already visited */
446 switch (get_irn_opcode(node)) {
458 /* we must handle Call nodes specially, because their call address input
459 do not expose a method address. */
460 set_irn_link(node, MARK);
461 for (i = get_Call_n_params(node) - 1; i >= 0; --i) {
462 ir_node *pred = get_Call_param(node, i);
463 if (mode_is_reference(get_irn_mode(pred))) {
464 free_mark(pred, set);
469 /* other nodes: Alle anderen Knoten nehmen wir als Verräter an, bis
470 * jemand das Gegenteil implementiert. */
471 set_irn_link(node, MARK);
472 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
473 ir_node *pred = get_irn_n(node, i);
474 if (mode_is_reference(get_irn_mode(pred))) {
475 free_mark(pred, set);
483 * Add all method addresses in global new style initializers to the set.
486 * We do NOT check the type here, just it it's an entity address.
487 * The reason for this is code like:
489 * void *p = function;
491 * which is sometimes used to anchor functions.
493 static void add_method_address_intitialzer(ir_initializer_t *initializer,
496 switch (initializer->kind) {
497 case IR_INITIALIZER_CONST: {
498 ir_node *n = initializer->consti.value;
500 /* let's check if it's the address of a function */
502 ir_entity *ent = get_Global_entity(n);
504 if (is_Method_type(get_entity_type(ent)))
505 eset_insert(set, ent);
509 case IR_INITIALIZER_TARVAL:
510 case IR_INITIALIZER_NULL:
512 case IR_INITIALIZER_COMPOUND: {
515 for (i = 0; i < initializer->compound.n_initializers; ++i) {
516 ir_initializer_t *sub_initializer
517 = initializer->compound.initializers[i];
518 add_method_address_intitialzer(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_intitialzer(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 /* insert "external visible" methods. */
602 if (get_entity_visibility(ent) != visibility_local) {
603 eset_insert(free_set, ent);
605 /* insert "sticky" methods. */
606 if (get_entity_stickyness(ent) == stickyness_sticky) {
607 eset_insert(free_set, ent);
610 set_using_irn_link(irg);
611 /* Find all method entities that gets "visible" trough this graphs,
612 * for instance because their address is stored. */
613 irg_walk_graph(irg, NULL, free_ana_walker, free_set);
614 clear_using_irn_link(irg);
617 /* insert all methods that are used in global variables initializers */
618 tp = get_glob_type();
619 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
620 ent = get_class_member(tp, i);
621 add_method_address(ent, free_set);
624 for (i = get_struct_n_members(tp) - 1; i >= 0; --i) {
625 ent = get_struct_member(tp, i);
626 add_method_address(ent, free_set);
629 /* the main program is even then "free", if it's not external visible. */
630 irg = get_irp_main_irg();
632 eset_insert(free_set, get_irg_entity(irg));
634 /* Finally, transform the set into an array. */
635 *length = eset_count(free_set);
636 arr = xmalloc(sizeof(ir_entity *) * (*length));
637 for (i = 0, ent = eset_first(free_set); ent; ent = eset_next(free_set)) {
640 eset_destroy(free_set);
645 /*--------------------------------------------------------------------------*/
646 /* Callee analysis. */
647 /*--------------------------------------------------------------------------*/
649 static void callee_ana_node(ir_node * node, eset * methods);
651 static void callee_ana_proj(ir_node *node, long n, eset *methods) {
652 assert(get_irn_mode(node) == mode_T);
653 if (get_irn_link(node) == MARK) {
654 /* already visited */
657 set_irn_link(node, MARK);
659 switch (get_irn_opcode(node)) {
661 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
662 * op_Tuple oder ein Knoten, der eine "freie Methode"
664 ir_node *pred = get_Proj_pred(node);
665 if (get_irn_link(pred) != MARK) {
666 if (is_Tuple(pred)) {
667 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
669 eset_insert(methods, unknown_entity); /* free method -> unknown */
676 callee_ana_node(get_Tuple_pred(node, n), methods);
680 eset_insert(methods, unknown_entity); /* free method -> unknown */
686 * Analyse a Call address.
688 * @param node the node representing the call address
689 * @param methods after call contains the set of all possibly called entities
691 static void callee_ana_node(ir_node *node, eset *methods) {
694 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
695 /* Beware of recursion */
696 if (get_irn_link(node) == MARK) {
697 /* already visited */
700 set_irn_link(node, MARK);
702 switch (get_irn_opcode(node)) {
704 /* A direct address call. We tread this as an external
705 call and ignore it completely. */
706 eset_insert(methods, unknown_entity); /* free method -> unknown */
709 if (get_SymConst_kind(node) == symconst_addr_ent) {
710 ir_entity *ent = get_SymConst_entity(node);
711 assert(ent && is_method_entity(ent));
712 eset_insert(methods, ent);
714 assert(get_SymConst_kind(node) == symconst_addr_name);
715 /* external method (because fix_symconst()!) */
716 eset_insert(methods, unknown_entity); /* free method -> unknown */
720 /* polymorphic method */
721 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
722 ir_entity *ent = get_Sel_method(node, i);
724 eset_insert(methods, ent);
726 eset_insert(methods, unknown_entity);
736 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
737 callee_ana_node(get_Phi_pred(node, i), methods);
742 callee_ana_node(get_Mux_false(node), methods);
743 callee_ana_node(get_Mux_true(node), methods);
747 for (i = get_Psi_n_conds(node) - 1; i >= 0; --i) {
748 callee_ana_node(get_Psi_val(node, i), methods);
750 callee_ana_node(get_Psi_default(node), methods);
754 callee_ana_node(get_Id_pred(node), methods);
758 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
765 eset_insert(methods, unknown_entity); /* free method -> unknown */
769 assert(0 && "invalid opcode or opcode not implemented");
775 * Walker: Analyses every Call node and calculates an array of possible
776 * callees for that call.
778 static void callee_walker(ir_node *call, void *env) {
781 eset *methods = eset_create();
786 callee_ana_node(get_Call_ptr(call), methods);
787 arr = NEW_ARR_F(ir_entity *, eset_count(methods));
788 for (i = 0, ent = eset_first(methods); ent; ent = eset_next(methods)) {
790 /* we want the unknown_entity on the zero position for easy tests later */
791 if (ent == unknown_entity) {
793 arr[0] = unknown_entity;
797 set_Call_callee_arr(call, ARR_LEN(arr), arr);
799 eset_destroy(methods);
804 * Walker: Removes all tuple.
806 static void remove_Tuples(ir_node *proj, void *env) {
809 if (! is_Proj(proj)) return;
811 nn = skip_Tuple(proj);
812 if (nn != proj) exchange(proj, nn);
817 * Determine for every Call the set of possibly called methods and stores it
818 * inside the Call (@see set_Call_callee()).
819 * Uses the sel_methods set with much be already calculated.
821 static void callee_ana(void) {
823 /* analyse all graphs */
824 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
825 ir_graph *irg = get_irp_irg(i);
826 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
827 set_irg_callee_info_state(irg, irg_callee_info_consistent);
829 set_irp_callee_info_state(irg_callee_info_consistent);
832 /*--------------------------------------------------------------------------*/
833 /* Cleanup after analyses. */
834 /*--------------------------------------------------------------------------*/
836 /** Frees intermediate data structures. */
837 static void sel_methods_dispose(void) {
840 for (ent = eset_first(entities); ent; ent = eset_next(entities)) {
841 ir_entity ** arr = get_entity_link(ent);
845 set_entity_link(ent, NULL);
847 eset_destroy(entities);
851 /*--------------------------------------------------------------------------*/
852 /* Freeing the callee arrays. */
853 /*--------------------------------------------------------------------------*/
855 static void destruct_walker(ir_node * node, void * env) {
858 remove_Call_callee_arr(node);
862 /*--------------------------------------------------------------------------*/
864 /*--------------------------------------------------------------------------*/
866 void cgana(int *length, ir_entity ***free_methods) {
867 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
869 *free_methods = get_free_methods(length);
871 sel_methods_dispose();
874 void free_callee_info(ir_graph *irg) {
875 irg_walk_graph(irg, destruct_walker, NULL, NULL);
876 set_irg_callee_info_state(irg, irg_callee_info_none);
879 void free_irp_callee_info(void) {
881 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
882 free_callee_info(get_irp_irg(i));
886 /* Optimize the address expressions passed to call nodes.
888 * This optimization performs the following transformations for
890 * - All SymConst operations that refer to intern methods are replaced
891 * by Const operations referring to the corresponding entity.
892 * - Sel nodes, that select entities that are not overwritten are
893 * replaced by Const nodes referring to the selected entity.
894 * - Sel nodes, for which no method exists at all are replaced by Bad
896 * - Sel nodes with a pointer input that is an Alloc node are replaced
897 * by Const nodes referring to the entity that implements the method in
898 * the type given by the Alloc node.
900 void opt_call_addrs(void) {
902 sel_methods_dispose();