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 assert(get_atomic_ent_value(inh_meth) && "constant entity without value");
88 assert((get_irn_op(get_atomic_ent_value(inh_meth)) == op_SymConst) &&
89 (get_SymConst_kind(get_atomic_ent_value(inh_meth)) == symconst_addr_ent) &&
90 "Complex constant values not supported -- address of method should be straight constant!");
92 return get_SymConst_entity(get_atomic_ent_value(inh_meth));
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);
198 /* replace SymConst(name)-operations by SymConst(ent) */
199 if (is_SymConst(node)) {
200 if (get_SymConst_kind(node) == symconst_addr_name) {
201 pmap_entry *entry = pmap_find(ldname_map, get_SymConst_name(node));
202 if (entry != NULL) { /* Method is declared in the compiled code */
203 assert(!"There should not be a SymConst[addr_name] addressing a method with an implementation"
204 "in this compilation unit. Use a SymConst[addr_ent].");
207 } else if (is_Sel(node) && is_Method_type(get_entity_type(get_Sel_entity(node)))) {
208 ir_entity *ent = get_SymConst_entity(get_atomic_ent_value(get_Sel_entity(node)));
209 assert(get_entity_peculiarity(ent) != peculiarity_inherited);
211 if (!eset_contains(entities, ent)) {
212 /* Entity not yet handled. Find all (internal or external)
213 * implemented methods that overwrites this entity.
214 * This set is stored in the entity link. */
215 set_entity_link(ent, get_impl_methods(ent));
216 eset_insert(entities, ent);
219 /* -- As an add on we get an optimization that removes polymorphic calls.
220 This optimization is more powerful than that in transform_node_Sel(). -- */
221 arr = get_entity_link(ent);
224 * The Sel node never returns a pointer to a usable method.
225 * We could not call it, but it may be description:
226 * We call a method in a dead part of the program.
228 assert(get_entity_peculiarity(ent) == peculiarity_description);
230 else if (get_opt_closed_world() && get_opt_dyn_meth_dispatch() &&
231 (ARR_LEN(arr) == 1 && arr[0] != NULL)) {
235 * The Sel node returns only one possible method.
236 * So we could replace the Sel node by a SymConst.
237 * This method must exists.
239 set_irg_current_block(current_ir_graph, get_nodes_block(node));
240 assert(get_entity_peculiarity(get_SymConst_entity(get_atomic_ent_value(arr[0]))) ==
241 peculiarity_existent);
242 new_node = copy_const_value(get_irn_dbg_info(node), get_atomic_ent_value(arr[0]));
243 DBG_OPT_POLY(node, new_node);
244 exchange(node, new_node);
250 * Initialize auxiliary data structures.
252 * Computes a set of entities that overwrite an entity and contain
253 * an implementation. The set is stored in the entity's link field.
255 * Further replaces Sel nodes where this set contains exactly one
256 * method by SymConst nodes.
257 * Finally asserts if there is a SymConst(name) if there could be a
260 static void sel_methods_init(void) {
262 pmap *ldname_map = pmap_create(); /* Map entity names to entities: to replace
263 SymConst(name) by SymConst(ent). */
264 assert(entities == NULL);
265 entities = eset_create();
266 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
267 ir_entity * ent = get_irg_entity(get_irp_irg(i));
268 /* only external visible methods are allowed to call by a SymConst_ptr_name */
269 if (get_entity_visibility(ent) != visibility_local) {
270 pmap_insert(ldname_map, (void *)get_entity_ld_ident(ent), ent);
274 all_irg_walk(sel_methods_walker, NULL, ldname_map);
275 pmap_destroy(ldname_map);
278 /*--------------------------------------------------------------------------*/
279 /* Find free methods.
281 * We expect that each entity has an array with all implementations in its
283 /*--------------------------------------------------------------------------*/
286 * Returns an array of all methods that could be called at a Sel node.
287 * This array contains every entry only once.
289 * @param sel the Sel node
291 static ir_entity ** get_Sel_arr(ir_node * sel) {
292 static ir_entity ** NULL_ARRAY = NULL;
297 ent = get_Sel_entity(sel);
298 ent = get_inherited_methods_implementation(ent);
300 assert(is_Method_type(get_entity_type(ent))); /* what else? */
301 arr = get_entity_link(ent);
305 /* "NULL" zeigt an, dass keine Implementierung existiert. Dies
306 * kann für polymorphe (abstrakte) Methoden passieren. */
308 NULL_ARRAY = NEW_ARR_F(ir_entity *, 0);
315 * Returns the number of possible called methods at a Sel node.
317 * @param sel the Sel node
319 static int get_Sel_n_methods(ir_node * sel) {
320 return ARR_LEN(get_Sel_arr(sel));
324 * Returns the ith possible called method entity at a Sel node.
326 static ir_entity * get_Sel_method(ir_node * sel, int pos) {
327 ir_entity ** arr = get_Sel_arr(sel);
328 assert(pos >= 0 && pos < ARR_LEN(arr));
333 static void free_mark(ir_node * node, eset * set);
335 static void free_mark_proj(ir_node * node, long n, eset * set) {
336 assert(get_irn_mode(node) == mode_T);
337 if (get_irn_link(node) == MARK) {
338 /* already visited */
341 set_irn_link(node, MARK);
342 switch (get_irn_opcode(node)) {
344 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
345 * op_Tuple oder ein Knoten, der in "free_ana_walker" behandelt
347 ir_node * pred = get_Proj_pred(node);
348 if (get_irn_link(pred) != MARK && get_irn_op(pred) == op_Tuple) {
349 free_mark_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, set);
351 /* nothing: da in "free_ana_walker" behandelt. */
357 free_mark(get_Tuple_pred(node, n), set);
361 free_mark_proj(get_Id_pred(node), n, set);
367 /* nothing: Die Operationen werden in free_ana_walker() selbst
372 assert(0 && "unexpected opcode or opcode not implemented");
375 set_irn_link(node, NULL);
379 * Called for predecessors nodes of "interesting" ones.
380 * Interesting ones include all nodes that can somehow make
383 * If a method (or a set of methods in case of polymorph calls) gets visible,
384 * add it to the set of 'free' methods
386 * @param node the current visited node
387 * @param set the set of all free methods
389 static void free_mark(ir_node *node, eset * set) {
392 if (get_irn_link(node) == MARK)
393 return; /* already visited */
395 set_irn_link(node, MARK);
397 switch (get_irn_opcode(node)) {
399 ir_entity *ent = get_Sel_entity(node);
400 if (is_method_entity(ent)) {
401 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
402 eset_insert(set, get_Sel_method(node, i));
408 if (get_SymConst_kind(node) == symconst_addr_ent) {
409 ir_entity *ent = get_SymConst_entity(node);
410 if (is_method_entity(ent)) {
411 eset_insert(set, ent);
414 assert(get_SymConst_kind(node) == symconst_addr_name);
415 /* nothing: SymConst points to extern method */
420 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
421 free_mark(get_Phi_pred(node, i), set);
425 free_mark_proj(get_Proj_pred(node), get_Proj_proj(node), set);
431 set_irn_link(node, NULL);
435 * post-walker. Find method addresses.
437 static void free_ana_walker(ir_node *node, void *env) {
441 if (get_irn_link(node) == MARK) {
442 /* already visited */
445 switch (get_irn_opcode(node)) {
457 /* we must handle Call nodes specially, because their call address input
458 do not expose a method address. */
459 set_irn_link(node, MARK);
460 for (i = get_Call_n_params(node) - 1; i >= 0; --i) {
461 ir_node *pred = get_Call_param(node, i);
462 if (mode_is_reference(get_irn_mode(pred))) {
463 free_mark(pred, set);
468 /* other nodes: Alle anderen Knoten nehmen wir als Verräter an, bis
469 * jemand das Gegenteil implementiert. */
470 set_irn_link(node, MARK);
471 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
472 ir_node *pred = get_irn_n(node, i);
473 if (mode_is_reference(get_irn_mode(pred))) {
474 free_mark(pred, set);
479 set_irn_link(node, NULL);
482 static void add_method_address_intitialzer(ir_initializer_t *initializer,
485 switch(initializer->kind) {
486 case IR_INITIALIZER_CONST: {
487 ir_node *n = initializer->consti.value;
489 /* let's check if it's the address of a function */
490 if (is_SymConst_addr_ent(n)) {
491 ir_entity *ent = get_SymConst_entity(n);
493 if (is_Method_type(get_entity_type(ent)))
494 eset_insert(set, ent);
498 case IR_INITIALIZER_TARVAL:
499 case IR_INITIALIZER_NULL:
501 case IR_INITIALIZER_COMPOUND: {
504 for(i = 0; i < initializer->compound.n_initializers; ++i) {
505 ir_initializer_t *sub_initializer
506 = initializer->compound.initializers[i];
507 add_method_address_intitialzer(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) {
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);
547 if (is_SymConst_addr_ent(n)) {
548 ent = get_SymConst_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 */
558 if (is_SymConst_addr_ent(n)) {
559 ir_entity *ent = get_SymConst_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 /* insert "external visible" methods. */
591 if (get_entity_visibility(ent) != visibility_local) {
592 eset_insert(free_set, ent);
594 /* insert "sticky" methods. */
595 if (get_entity_stickyness(ent) == stickyness_sticky) {
596 eset_insert(free_set, ent);
599 /* Find all method entities that gets "visible" trough this graphs,
600 * for instance because their address is stored. */
601 irg_walk_graph(irg, NULL, free_ana_walker, free_set);
604 /* insert all methods that are used in global variables initializers */
605 tp = get_glob_type();
606 for (i = get_class_n_members(tp) - 1; i >= 0; --i) {
607 ent = get_class_member(tp, i);
608 add_method_address(ent, free_set);
611 for (i = get_struct_n_members(tp) - 1; i >= 0; --i) {
612 ent = get_struct_member(tp, i);
613 add_method_address(ent, free_set);
616 /* the main program is even then "free", if it's not external visible. */
617 irg = get_irp_main_irg();
619 eset_insert(free_set, get_irg_entity(irg));
621 /* Finally, transform the set into an array. */
622 *length = eset_count(free_set);
623 arr = xmalloc(sizeof(ir_entity *) * (*length));
624 for (i = 0, ent = eset_first(free_set); ent; ent = eset_next(free_set)) {
627 eset_destroy(free_set);
632 /*--------------------------------------------------------------------------*/
633 /* Callee analysis. */
634 /*--------------------------------------------------------------------------*/
636 static void callee_ana_node(ir_node * node, eset * methods);
638 static void callee_ana_proj(ir_node *node, long n, eset *methods) {
639 assert(get_irn_mode(node) == mode_T);
640 if (get_irn_link(node) == MARK) {
641 /* already visited */
644 set_irn_link(node, MARK);
646 switch (get_irn_opcode(node)) {
648 /* proj_proj: in einem "sinnvollen" Graphen kommt jetzt ein
649 * op_Tuple oder ein Knoten, der eine "freie Methode"
651 ir_node *pred = get_Proj_pred(node);
652 if (get_irn_link(pred) != MARK) {
653 if (is_Tuple(pred)) {
654 callee_ana_proj(get_Tuple_pred(pred, get_Proj_proj(node)), n, methods);
656 eset_insert(methods, unknown_entity); /* free method -> unknown */
663 callee_ana_node(get_Tuple_pred(node, n), methods);
667 eset_insert(methods, unknown_entity); /* free method -> unknown */
671 set_irn_link(node, NULL);
675 * Analyse a Call address.
677 * @param node the node representing the call address
678 * @param methods after call contains the set of all possibly called entities
680 static void callee_ana_node(ir_node *node, eset *methods) {
683 assert(mode_is_reference(get_irn_mode(node)) || is_Bad(node));
684 /* Beware of recursion */
685 if (get_irn_link(node) == MARK) {
686 /* already visited */
689 set_irn_link(node, MARK);
691 switch (get_irn_opcode(node)) {
693 /* A direct address call. We tread this as an external
694 call and ignore it completely. */
695 eset_insert(methods, unknown_entity); /* free method -> unknown */
698 if (get_SymConst_kind(node) == symconst_addr_ent) {
699 ir_entity *ent = get_SymConst_entity(node);
700 assert(ent && is_method_entity(ent));
701 eset_insert(methods, ent);
703 assert(get_SymConst_kind(node) == symconst_addr_name);
704 /* external method (because fix_symconst()!) */
705 eset_insert(methods, unknown_entity); /* free method -> unknown */
709 /* polymorphic method */
710 for (i = get_Sel_n_methods(node) - 1; i >= 0; --i) {
711 ir_entity *ent = get_Sel_method(node, i);
713 eset_insert(methods, ent);
715 eset_insert(methods, unknown_entity);
725 for (i = get_Phi_n_preds(node) - 1; i >= 0; --i) {
726 callee_ana_node(get_Phi_pred(node, i), methods);
731 callee_ana_node(get_Mux_false(node), methods);
732 callee_ana_node(get_Mux_true(node), methods);
736 for (i = get_Psi_n_conds(node) - 1; i >= 0; --i) {
737 callee_ana_node(get_Psi_val(node, i), methods);
739 callee_ana_node(get_Psi_default(node), methods);
743 callee_ana_node(get_Id_pred(node), methods);
747 callee_ana_proj(get_Proj_pred(node), get_Proj_proj(node), methods);
754 eset_insert(methods, unknown_entity); /* free method -> unknown */
758 assert(0 && "invalid opcode or opcode not implemented");
762 set_irn_link(node, NULL);
766 * Walker: Analyses every Call node and calculates an array of possible
767 * callees for that call.
769 static void callee_walker(ir_node *call, void *env) {
772 eset *methods = eset_create();
777 callee_ana_node(get_Call_ptr(call), methods);
778 arr = NEW_ARR_F(ir_entity *, eset_count(methods));
779 for (i = 0, ent = eset_first(methods); ent; ent = eset_next(methods)) {
781 /* we want the unknown_entity on the zero position for easy tests later */
782 if (ent == unknown_entity) {
784 arr[0] = unknown_entity;
788 set_Call_callee_arr(call, ARR_LEN(arr), arr);
790 eset_destroy(methods);
795 * Walker: Removes all tuple.
797 static void remove_Tuples(ir_node *proj, void *env) {
800 if (! is_Proj(proj)) return;
802 nn = skip_Tuple(proj);
803 if (nn != proj) exchange(proj, nn);
808 * Determine for every Call the set of possibly called methods and stores it
809 * inside the Call (@see set_Call_callee()).
810 * Uses the sel_methods set with much be already calculated.
812 static void callee_ana(void) {
814 /* analyse all graphs */
815 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
816 ir_graph *irg = get_irp_irg(i);
817 irg_walk_graph(irg, callee_walker, remove_Tuples, NULL);
818 set_irg_callee_info_state(irg, irg_callee_info_consistent);
820 set_irp_callee_info_state(irg_callee_info_consistent);
823 /*--------------------------------------------------------------------------*/
824 /* Cleanup after analyses. */
825 /*--------------------------------------------------------------------------*/
827 /** Frees intermediate data structures. */
828 static void sel_methods_dispose(void) {
831 for (ent = eset_first(entities); ent; ent = eset_next(entities)) {
832 ir_entity ** arr = get_entity_link(ent);
836 set_entity_link(ent, NULL);
838 eset_destroy(entities);
842 /*--------------------------------------------------------------------------*/
843 /* Freeing the callee arrays. */
844 /*--------------------------------------------------------------------------*/
846 static void destruct_walker(ir_node * node, void * env) {
849 remove_Call_callee_arr(node);
853 /*--------------------------------------------------------------------------*/
855 /*--------------------------------------------------------------------------*/
857 void cgana(int *length, ir_entity ***free_methods) {
858 /* Optimize Sel/SymConst nodes and compute all methods that implement an entity. */
860 *free_methods = get_free_methods(length);
862 sel_methods_dispose();
865 void free_callee_info(ir_graph *irg) {
866 irg_walk_graph(irg, destruct_walker, NULL, NULL);
867 set_irg_callee_info_state(irg, irg_callee_info_none);
870 void free_irp_callee_info(void) {
872 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
873 free_callee_info(get_irp_irg(i));
877 /* Optimize the address expressions passed to call nodes.
879 * This optimization performs the following transformations for
881 * - All SymConst operations that refer to intern methods are replaced
882 * by Const operations referring to the corresponding entity.
883 * - Sel nodes, that select entities that are not overwritten are
884 * replaced by Const nodes referring to the selected entity.
885 * - Sel nodes, for which no method exists at all are replaced by Bad
887 * - Sel nodes with a pointer input that is an Alloc node are replaced
888 * by Const nodes referring to the entity that implements the method in
889 * the type given by the Alloc node.
891 void opt_call_addrs(void) {
893 sel_methods_dispose();