2 * Copyright (C) 1995-2011 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
26 * Interprocedural analysis to estimate the calling relation.
28 * This analysis computes all entities representing methods that
29 * can be called at a Call node. Further it computes a set of
30 * methods that are 'free', i.e., their adress is handled by
31 * the program directly, or they are visible external.
50 #include "dbginfo_t.h"
51 #include "iropt_dbg.h"
59 /* unambiguous address used as a mark. */
60 static void *MARK = &MARK;
62 static pset *entities = NULL;
64 /*--------------------------------------------------------------------------*/
66 /*--------------------------------------------------------------------------*/
69 /*--------------------------------------------------------------------------*/
70 /* Initialize datastructures, remove unwanted constructs, optimize */
71 /* call target computations. */
72 /*--------------------------------------------------------------------------*/
74 /** Collect the entity representing the implementation of this
75 * method (not the same if inherited) and all entities for overwriting
76 * implementations in parameter set.
77 * A recursive descend in the overwritten relation.
78 * Cycle-free, therefore must terminate.
80 * @param method the overwritten method
81 * @param set A set of entities.
83 * @return Number of entities in set.
85 static size_t collect_impls(ir_entity *method, pset *set)
90 if (get_entity_irg(method) != NULL) {
91 /* has an implementation */
92 pset_insert_ptr(set, method);
96 /*- recursive descent -*/
97 for (i = get_entity_n_overwrittenby(method); i > 0;)
98 size += collect_impls(get_entity_overwrittenby(method, --i), set);
103 * Determine all methods that overwrite the given method (and implement it).
104 * The returned array must be freed by the caller (see DEL_ARR_F).
105 * If the set of overwriting methods is empty, returns NULL.
107 * @param method the method
109 static ir_entity **get_impl_methods(ir_entity *method)
112 pset *set = pset_new_ptr_default();
115 /* Collect all method entities that can be called here */
116 size = collect_impls(method, set);
119 /* no overwriting methods found */
123 arr = NEW_ARR_F(ir_entity *, size);
124 foreach_pset(set, ir_entity*, ent) {
132 /** Analyze address computations.
134 * Compute for all Sel nodes the set of methods that can be selected.
135 * For each entity we store the set of subentities in the link field.
137 * Further do some optimizations:
138 * - Call standard optimizations for Sel nodes: this removes polymorphic
140 * - If the node is a SymConst(name) replace it by SymConst(ent) if possible.
141 * For this we precomputed a map name->entity. Nowadays, we no more support
143 * - If the node is a Sel:
144 * If we found only a single method that can be called, replace the Sel
145 * by a SymConst. This is more powerful than the analysis in opt_polymorphy,
146 * as here we walk the type graph. In opt_polymorphy we only apply a local
149 * @param node The node to analyze
150 * @param env A map that maps names of entities to the entities.
152 static void sel_methods_walker(ir_node *node, void *env)
157 /* Call standard optimizations */
159 ir_node *new_node = optimize_in_place(node);
160 if (node != new_node) {
161 exchange(node, new_node);
166 if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
167 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
169 if (!pset_find_ptr(entities, ent)) {
170 /* Entity not yet handled. Find all (internal or external)
171 * implemented methods that overwrites this entity.
172 * This set is stored in the entity link. */
173 set_entity_link(ent, get_impl_methods(ent));
174 pset_insert_ptr(entities, ent);
177 /* -- As an add on we get an optimization that removes polymorphic calls.
178 This optimization is more powerful than that in transform_node_Sel(). -- */
179 arr = (ir_entity**) get_entity_link(ent);
182 * The Sel node never returns a pointer to a usable method.
183 * We could not call it, but it may be description:
184 * We call a method in a dead part of the program.
186 assert(get_entity_irg(ent) == NULL);
189 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
190 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
194 * The Sel node returns only one possible method.
195 * So we could replace the Sel node by a SymConst.
196 * This method must exists.
198 assert(get_entity_irg(arr[0]) != NULL);
199 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]), get_nodes_block(node));
200 DBG_OPT_POLY(node, new_node);
201 exchange(node, new_node);
208 * Initialize auxiliary data structures.
210 * Computes a set of entities that overwrite an entity and contain
211 * an implementation. The set is stored in the entity's link field.
213 * Further replaces Sel nodes where this set contains exactly one
214 * method by SymConst nodes.
215 * Finally asserts if there is a SymConst(name) if there could be a
218 static void sel_methods_init(void)
221 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
222 SymConst(name) by SymConst(ent). */
223 assert(entities == NULL);
224 entities = pset_new_ptr_default();
225 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
226 ir_entity * ent = get_irg_entity(get_irp_irg(i));
227 /* only external visible methods are allowed to call by a SymConst_ptr_name */
228 if (entity_is_externally_visible(ent)) {
229 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
233 all_irg_walk(sel_methods_walker, NULL, NULL);
234 pmap_destroy(ldname_map);
237 /*--------------------------------------------------------------------------*/
238 /* Find free methods.
240 * We expect that each entity has an array with all implementations in its
242 /*--------------------------------------------------------------------------*/
245 * Returns an array of all methods that could be called at a Sel node.
246 * This array contains every entry only once.
248 * @param sel the Sel node
250 static ir_entity ** get_Sel_arr(ir_node * sel)
252 static ir_entity ** NULL_ARRAY = NULL;
257 ent = get_Sel_entity(sel);
259 assert(is_Method_type(get_entity_type(ent))); /* what else? */
260 arr = (ir_entity**) get_entity_link(ent);
264 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
265 * kann f�r polymorphe (abstrakte) Methoden passieren. */
267 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
274 * Returns the number of possible called methods at a Sel node.
276 * @param sel the Sel node
278 static size_t get_Sel_n_methods(ir_node * sel)
280 return ARR_LEN(get_Sel_arr(sel));
284 * Returns the ith possible called method entity at a Sel node.
286 static ir_entity * get_Sel_method(ir_node * sel, size_t pos)
288 ir_entity ** arr = get_Sel_arr(sel);
289 assert(pos < ARR_LEN(arr));
294 static void free_mark(ir_node *node, pset *set);
296 static void free_mark_proj(ir_node *node, long n, pset *set)
298 assert(get_irn_mode(node) == mode_T);
299 if (get_irn_link(node) == MARK) {
300 /* already visited */
303 set_irn_link(node, MARK);
304 switch (get_irn_opcode(node)) {
306 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
307 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
309 ir_node * pred = get_Proj_pred(node);
310 if (get_irn_link(pred) != MARK && is_Tuple(pred)) {
311 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
313 /* nothing: da in "free_ana_walker" behandelt. */
319 free_mark(get_Tuple_pred(node, n), set);
323 free_mark_proj(get_Id_pred(node), n, set);
329 /* nothing: Die Operationen werden in free_ana_walker() selbst
334 assert(0 && "unexpected opcode or opcode not implemented");
337 // set_irn_link(node, NULL);
341 * Called for predecessors nodes of "interesting" ones.
342 * Interesting ones include all nodes that can somehow make
345 * If a method (or a set of methods in case of polymorph calls) gets visible,
346 * add it to the set of 'free' methods
348 * @param node the current visited node
349 * @param set the set of all free methods
351 static void free_mark(ir_node *node, pset *set)
353 if (get_irn_link(node) == MARK)
354 return; /* already visited */
356 set_irn_link(node, MARK);
358 switch (get_irn_opcode(node)) {
360 ir_entity *ent = get_Sel_entity(node);
361 if (is_method_entity(ent)) {
363 for (i = 0, n = get_Sel_n_methods(node); i < n; ++i) {
364 pset_insert_ptr(set, get_Sel_method(node, i));
370 if (get_SymConst_kind(node) == symconst_addr_ent) {
371 ir_entity *ent = get_SymConst_entity(node);
372 if (is_method_entity(ent)) {
373 pset_insert_ptr(set, ent);
381 for (i = 0, n = get_Phi_n_preds(node); i < n; ++i) {
382 free_mark(get_Phi_pred(node, i), set);
387 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
396 * post-walker. Find method addresses.
398 static void free_ana_walker(ir_node *node, void *env)
400 pset *set = (pset*) env;
402 if (get_irn_link(node) == MARK) {
403 /* already visited */
406 switch (get_irn_opcode(node)) {
420 /* we must handle Call nodes specially, because their call address input
421 do not expose a method address. */
422 set_irn_link(node, MARK);
423 for (i = 0, n = get_Call_n_params(node); i < n; ++i) {
424 ir_node *pred = get_Call_param(node, i);
425 if (mode_is_reference(get_irn_mode(pred))) {
426 free_mark(pred, set);
433 /* other nodes: Alle anderen Knoten nehmen wir als Verr�ter an, bis
434 * jemand das Gegenteil implementiert. */
435 set_irn_link(node, MARK);
436 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
437 ir_node *pred = get_irn_n(node, i);
438 if (mode_is_reference(get_irn_mode(pred))) {
439 free_mark(pred, set);
448 * Add all method addresses in global new style initializers to the set.
451 * We do NOT check the type here, just if it's an entity address.
452 * The reason for this is code like:
454 * void *p = function;
456 * which is sometimes used to anchor functions.
458 static void add_method_address_inititializer(ir_initializer_t *initializer,
464 switch (initializer->kind) {
465 case IR_INITIALIZER_CONST:
466 n = initializer->consti.value;
468 /* let's check if it's the address of a function */
469 if (is_SymConst_addr_ent(n)) {
470 ir_entity *ent = get_SymConst_entity(n);
472 if (is_Method_type(get_entity_type(ent)))
473 pset_insert_ptr(set, ent);
476 case IR_INITIALIZER_TARVAL:
477 case IR_INITIALIZER_NULL:
479 case IR_INITIALIZER_COMPOUND:
480 for (i = 0; i < initializer->compound.n_initializers; ++i) {
481 ir_initializer_t *sub_initializer
482 = initializer->compound.initializers[i];
483 add_method_address_inititializer(sub_initializer, set);
487 panic("invalid initializer found");
491 * Add all method addresses in global initializers to the set.
494 * We do NOT check the type here, just if it's an entity address.
495 * The reason for this is code like:
497 * void *p = function;
499 * which is sometimes used to anchor functions.
501 static void add_method_address(ir_entity *ent, pset *set)
505 /* ignore methods: these of course reference their addresses
506 * TODO: remove this later once this incorrect self-initialisation is gone
508 tp = get_entity_type(ent);
509 if (is_Method_type(tp))
512 if (ent->initializer != NULL) {
513 add_method_address_inititializer(get_entity_initializer(ent), set);
518 * returns a list of 'free' methods, i.e., the methods that can be called
519 * from external or via function pointers.
521 * Die Datenstrukturen für sel-Methoden (sel_methods) muß vor dem
522 * Aufruf von "get_free_methods" aufgebaut sein. Die (internen)
523 * SymConst(name)-Operationen müssen in passende SymConst(ent)-Operationen
524 * umgewandelt worden sein, d.h. SymConst-Operationen verweisen immer
525 * auf eine echt externe Methode.
527 static size_t get_free_methods(ir_entity ***free_methods)
529 pset *free_set = pset_new_ptr_default();
537 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
539 irg = get_irp_irg(i);
540 ent = get_irg_entity(irg);
541 linkage = get_entity_linkage(ent);
543 if ((linkage & IR_LINKAGE_HIDDEN_USER) || entity_is_externally_visible(ent)) {
544 pset_insert_ptr(free_set, ent);
547 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
548 /* Find all method entities that gets "visible" through this graphs,
549 * for instance because their address is stored. */
550 irg_walk_graph(irg, firm_clear_link, free_ana_walker, free_set);
551 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
554 /* insert all methods that are used in global variables initializers */
555 tp = get_glob_type();
556 for (j = 0, m = get_class_n_members(tp); j < m; ++j) {
557 ent = get_class_member(tp, j);
558 add_method_address(ent, free_set);
561 for (j = 0, m = get_compound_n_members(tp); j < m; ++j) {
562 ent = get_compound_member(tp, j);
563 add_method_address(ent, free_set);
566 /* the main program is even then "free", if it's not external visible. */
567 irg = get_irp_main_irg();
569 pset_insert_ptr(free_set, get_irg_entity(irg));
571 /* Finally, transform the set into an array. */
572 length = pset_count(free_set);
573 arr = XMALLOCN(ir_entity*, length);
575 foreach_pset(free_set, ir_entity*, ent) {
584 /*--------------------------------------------------------------------------*/
585 /* Callee analysis. */
586 /*--------------------------------------------------------------------------*/
588 static void callee_ana_node(ir_node *node, pset *methods);
590 static void callee_ana_proj(ir_node *node, long n, pset *methods)
592 assert(get_irn_mode(node) == mode_T);
593 if (get_irn_link(node) == MARK) {
594 /* already visited */
597 set_irn_link(node, MARK);
599 switch (get_irn_opcode(node)) {
601 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
602 * op_Tuple oder ein Knoten, der eine "freie Methode"
604 ir_node *pred = get_Proj_pred(node);
605 if (get_irn_link(pred) != MARK) {
606 if (is_Tuple(pred)) {
607 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
609 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
616 callee_ana_node(get_Tuple_pred(node, n), methods);
620 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
626 * Analyse a Call address.
628 * @param node the node representing the call address
629 * @param methods after call contains the set of all possibly called entities
631 static void callee_ana_node(ir_node *node, pset *methods)
633 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
634 /* Beware of recursion */
635 if (get_irn_link(node) == MARK) {
636 /* already visited */
639 set_irn_link(node, MARK);
641 switch (get_irn_opcode(node)) {
643 /* A direct address call. We tread this as an external
644 call and ignore it completely. */
645 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
649 ir_entity *ent = get_SymConst_entity(node);
650 assert(ent && is_method_entity(ent));
651 pset_insert_ptr(methods, ent);
656 /* polymorphic method */
658 for (i = 0, n = get_Sel_n_methods(node); i < n; ++i) {
659 ir_entity *ent = get_Sel_method(node, i);
661 pset_insert_ptr(methods, ent);
663 pset_insert_ptr(methods, get_unknown_entity());
675 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
676 callee_ana_node(get_Phi_pred(node, i), methods);
682 callee_ana_node(get_Mux_false(node), methods);
683 callee_ana_node(get_Mux_true(node), methods);
687 callee_ana_node(get_Id_pred(node), methods);
691 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
698 pset_insert_ptr(methods, get_unknown_entity()); /* free method -> unknown */
702 assert(0 && "invalid opcode or opcode not implemented");
708 * Walker: Analyses every Call node and calculates an array of possible
709 * callees for that call.
711 static void callee_walker(ir_node *call, void *env)
715 pset *methods = pset_new_ptr_default();
720 callee_ana_node(get_Call_ptr(call), methods);
721 arr = NEW_ARR_F(ir_entity*, pset_count(methods));
723 foreach_pset(methods, ir_entity*, ent) {
725 /* we want the unknown_entity on the zero position for easy tests later */
726 if (is_unknown_entity(ent)) {
728 arr[0] = get_unknown_entity();
732 set_Call_callee_arr(call, ARR_LEN(arr), arr);
739 * Walker: Removes all tuple.
741 static void remove_Tuples(ir_node *proj, void *env)
745 if (! is_Proj(proj)) return;
747 nn = skip_Tuple(proj);
748 if (nn != proj) exchange(proj, nn);
753 * Determine for every Call the set of possibly called methods and stores it
754 * inside the Call (@see set_Call_callee()).
755 * Uses the sel_methods set with much be already calculated.
757 static void callee_ana(void)
760 /* analyse all graphs */
761 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
762 ir_graph *irg = get_irp_irg(i);
763 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
764 set_irg_callee_info_state(irg, irg_callee_info_consistent);
766 set_irp_callee_info_state(irg_callee_info_consistent);
769 /*--------------------------------------------------------------------------*/
770 /* Cleanup after analyses. */
771 /*--------------------------------------------------------------------------*/
773 /** Frees intermediate data structures. */
774 static void sel_methods_dispose(void)
778 foreach_pset(entities, ir_entity*, ent) {
779 ir_entity **arr = (ir_entity**) get_entity_link(ent);
783 set_entity_link(ent, NULL);
789 static void destruct_walker(ir_node * node, void * env)
793 remove_Call_callee_arr(node);
797 size_t cgana(ir_entity ***free_methods)
800 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
802 length = get_free_methods(free_methods);
804 sel_methods_dispose();
808 void free_callee_info(ir_graph *irg)
810 irg_walk_graph(irg, destruct_walker, NULL, NULL);
811 set_irg_callee_info_state(irg, irg_callee_info_none);
814 void free_irp_callee_info(void)
817 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
818 free_callee_info(get_irp_irg(i));
822 void opt_call_addrs(void)
824 /* Optimize the address expressions passed to call nodes.
826 * This optimization performs the following transformations for
828 * - All SymConst operations that refer to intern methods are replaced
829 * by Const operations referring to the corresponding entity.
830 * - Sel nodes, that select entities that are not overwritten are
831 * replaced by Const nodes referring to the selected entity.
832 * - Sel nodes, for which no method exists at all are replaced by Bad
834 * - Sel nodes with a pointer input that is an Alloc node are replaced
835 * by Const nodes referring to the entity that implements the method in
836 * the type given by the Alloc node.
839 sel_methods_dispose();