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 Removal of unreachable methods.
23 * @author Hubert Schmid
29 * Entfernen von nicht erreichbaren (aufrufbaren) Methoden. Die Menge
30 * der nicht erreichbaren Methoden wird aus der Abschätzung der
31 * Aufrufrelation bestimmt.
48 DEBUG_ONLY(static firm_dbg_module_t *dbg);
51 * Walker: adds Call operations to a head's link list.
53 static void collect_call(ir_node *node, void *env)
55 ir_node *head = (ir_node*)env;
58 set_irn_link(node, get_irn_link(head));
59 set_irn_link(head, node);
63 /* garbage collect methods: mark and remove */
64 void gc_irgs(int n_keep, ir_entity ** keep_arr)
66 void * MARK = &MARK; /* @@@ gefaehrlich!!! Aber wir markieren hoechstens zu viele ... */
69 FIRM_DBG_REGISTER(dbg, "firm.opt.cgopt");
71 if (n_keep >= get_irp_n_irgs()) {
72 /* Shortcut. Obviously we have to keep all methods. */
76 DB((dbg, LEVEL_1, "dead method elimination\n"));
78 /* Mark entities that are alive. */
80 ir_entity **marked = NEW_ARR_F(ir_entity *, n_keep);
81 for (i = 0; i < n_keep; ++i) {
82 marked[i] = keep_arr[i];
83 set_entity_link(marked[i], MARK);
84 DB((dbg, LEVEL_1, " method %+F kept alive.\n", marked[i]));
87 for (i = 0; i < ARR_LEN(marked); ++i) {
88 ir_graph *irg = get_entity_irg(marked[i]);
94 node = get_irg_end(irg);
97 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
98 irg_walk_graph(irg, firm_clear_link, collect_call, node);
101 for (node = (ir_node*)get_irn_link(node); node != NULL;
102 node = (ir_node*)get_irn_link(node)) {
104 assert(is_Call(node));
106 for (i = get_Call_n_callees(node) - 1; i >= 0; --i) {
107 ir_entity *ent = get_Call_callee(node, i);
109 if (get_entity_irg(ent) && get_entity_link(ent) != MARK) {
110 set_entity_link(ent, MARK);
111 ARR_APP1(ir_entity *, marked, ent);
113 DB((dbg, LEVEL_1, " method %+F can be called from Call %+F: kept alive.\n",
118 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
124 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
125 ir_graph *irg = get_irp_irg(i);
126 ir_entity *ent = get_irg_entity(irg);
128 if (get_entity_link(ent) == MARK)
131 DB((dbg, LEVEL_1, " freeing method %+F\n", ent));
139 * Wrapper for running gc_irgs() as an ir_prog pass.
141 static void pass_wrapper(void)
143 ir_entity **keep_methods;
146 /* Analysis that finds the free methods,
147 i.e. methods that are dereferenced.
148 Optimizes polymorphic calls :-). */
149 cgana(&arr_len, &keep_methods);
151 /* Remove methods that are never called. */
152 gc_irgs(arr_len, keep_methods);
157 ir_prog_pass_t *gc_irgs_pass(const char *name)
159 return def_prog_pass(name ? name : "cgana", pass_wrapper);