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 Removal of unreachable methods.
23 * @author Hubert Schmid
28 * Entfernen von nicht erreichbaren (aufrufbaren) Methoden. Die Menge
29 * der nicht erreichbaren Methoden wird aus der Abschätzung der
30 * Aufrufrelation bestimmt.
47 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
50 * Walker: adds Call operations to a head's link list.
52 static void collect_call(ir_node *node, void *env)
54 ir_node *head = (ir_node*)env;
57 set_irn_link(node, get_irn_link(head));
58 set_irn_link(head, node);
62 /* garbage collect methods: mark and remove */
63 void gc_irgs(size_t n_keep, ir_entity ** keep_arr)
65 void * MARK = &MARK; /* @@@ gefaehrlich!!! Aber wir markieren hoechstens zu viele ... */
68 FIRM_DBG_REGISTER(dbg, "firm.opt.cgopt");
70 if (n_keep >= get_irp_n_irgs()) {
71 /* Shortcut. Obviously we have to keep all methods. */
75 DB((dbg, LEVEL_1, "dead method elimination\n"));
77 /* Mark entities that are alive. */
79 ir_entity **marked = NEW_ARR_F(ir_entity *, n_keep);
82 for (idx = 0; idx < n_keep; ++idx) {
83 marked[idx] = keep_arr[idx];
84 set_entity_link(marked[idx], MARK);
85 DB((dbg, LEVEL_1, " method %+F kept alive.\n", marked[idx]));
88 for (idx = 0; idx < ARR_LEN(marked); ++idx) {
89 ir_graph *irg = get_entity_irg(marked[idx]);
95 node = get_irg_end(irg);
98 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
99 irg_walk_graph(irg, firm_clear_link, collect_call, node);
102 for (node = (ir_node*)get_irn_link(node); node != NULL;
103 node = (ir_node*)get_irn_link(node)) {
105 assert(is_Call(node));
107 for (i = get_Call_n_callees(node); i > 0;) {
108 ir_entity *ent = get_Call_callee(node, --i);
110 if (get_entity_irg(ent) && get_entity_link(ent) != MARK) {
111 set_entity_link(ent, MARK);
112 ARR_APP1(ir_entity *, marked, ent);
114 DB((dbg, LEVEL_1, " method %+F can be called from Call %+F: kept alive.\n",
119 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
125 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
126 ir_graph *irg = get_irp_irg(i);
127 ir_entity *ent = get_irg_entity(irg);
129 if (get_entity_link(ent) == MARK)
132 DB((dbg, LEVEL_1, " freeing method %+F\n", ent));
140 * Wrapper for running gc_irgs() as an ir_prog pass.
142 static void pass_wrapper(void)
144 ir_entity **keep_methods;
147 /* Analysis that finds the free methods,
148 i.e. methods that are dereferenced.
149 Optimizes polymorphic calls :-). */
150 arr_len = cgana(&keep_methods);
152 /* Remove methods that are never called. */
153 gc_irgs(arr_len, keep_methods);
158 ir_prog_pass_t *gc_irgs_pass(const char *name)
160 return def_prog_pass(name ? name : "cgana", pass_wrapper);