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 Implementation of cdep
23 * @author Christoph Mallon
39 typedef struct cdep_info {
40 pmap *cdep_map; /**< A map to find the list of all control dependence nodes for a block. */
41 struct obstack obst; /**< An obstack where all cdep data lives on. */
44 static cdep_info *cdep_data;
46 /* Return a list of all control dependences of a block. */
47 ir_cdep *find_cdep(const ir_node *block) {
48 return pmap_get(cdep_data->cdep_map, block);
51 /* Replace the control dependence info of old by the info of nw. */
52 void exchange_cdep(ir_node *old, const ir_node *nw) {
53 ir_cdep *cdep = find_cdep(nw);
54 pmap_insert(cdep_data->cdep_map, old, cdep);
58 * Adds a control dependence from node to dep_on.
60 static void add_cdep(ir_node *node, ir_node *dep_on) {
61 ir_cdep *dep = find_cdep(node);
63 ir_fprintf(stderr, "Adding cdep of %+F on %+F\n", node, dep_on);
67 ir_cdep *newdep = OALLOC(&cdep_data->obst, ir_cdep);
69 newdep->node = dep_on;
71 pmap_insert(cdep_data->cdep_map, node, newdep);
76 if (dep->node == dep_on) return;
77 if (dep->next == NULL) break;
80 newdep = OALLOC(&cdep_data->obst, ir_cdep);
81 newdep->node = dep_on;
87 typedef struct cdep_env {
93 * Pre-block-walker: calculate the control dependence
95 static void cdep_pre(ir_node *node, void *ctx) {
100 * start and end block have no control dependency
102 if (node == env->start_block) return;
103 if (node == env->end_block) return;
105 for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
106 ir_node *pred = get_Block_cfgpred_block(node, i);
110 if (is_Bad(pred)) continue;
112 pdom = get_Block_ipostdom(pred);
113 for (dependee = node; dependee != pdom; dependee = get_Block_ipostdom(dependee)) {
114 assert(!is_Bad(pdom));
115 add_cdep(dependee, pred);
122 * A block edge hook: add all cdep edges of block.
124 static int cdep_edge_hook(FILE *F, ir_node *block)
129 ir_node *pdom = get_Block_ipostdom(block);
133 "edge:{sourcename:\"n%ld\" targetname:\"n%ld\" color:gold}\n",
134 get_irn_node_nr(pdom), get_irn_node_nr(block)
139 for (cd = find_cdep(block); cd != NULL; cd = cd->next) {
142 "edge:{sourcename:\"n%ld\" targetname:\"n%ld\" "
143 "linestyle:dashed color:gold}\n",
144 get_irn_node_nr(block), get_irn_node_nr(cd->node)
151 /* Compute the control dependence graph for a graph. */
152 void compute_cdep(ir_graph *irg) {
157 cdep_data = XMALLOC(cdep_info);
158 obstack_init(&cdep_data->obst);
160 cdep_data->cdep_map = pmap_create();
162 assure_postdoms(irg);
164 /* we must temporary change the post dominator relation:
165 the ipdom of the startblock is the end block.
166 Firm does NOT add the phantom edge from Start to End.
168 env.start_block = get_irg_start_block(irg);
169 env.end_block = get_irg_end_block(irg);
171 rem = get_Block_ipostdom(env.start_block);
172 set_Block_ipostdom(env.start_block, env.end_block);
174 irg_block_walk_graph(irg, cdep_pre, NULL, &env);
177 set_dump_block_edge_hook(cdep_edge_hook);
178 dump_ir_block_graph(irg, "_cdep");
179 set_dump_block_edge_hook(NULL);
181 (void) cdep_edge_hook;
184 /* restore the post dominator relation */
185 set_Block_ipostdom(env.start_block, rem);
188 /* Free the control dependence info. */
189 void free_cdep(ir_graph *irg) {
191 if (cdep_data != NULL) {
192 pmap_destroy(cdep_data->cdep_map);
193 obstack_free(&cdep_data->obst, NULL);
199 /* Check whether dependee is (directly) control dependent on candidate. */
200 int is_cdep_on(const ir_node *dependee, const ir_node *candidate) {
203 for (dep = find_cdep(dependee); dep != NULL; dep = dep->next) {
204 if (dep->node == candidate) return 1;
209 /* Check whether dependee is (possible iterated) control dependent on candidate. */
210 int is_iterated_cdep_on(ir_node *dependee, ir_node *candidate) {
213 while ((dep = find_cdep(dependee)) != NULL) {
214 if (dep->next != NULL) return 0;
215 if (dep->node == candidate) return 1;
216 dependee = dep->node;
221 /* If block is control dependent on exactly one node, return this node, else NULL. */
222 ir_node *get_unique_cdep(const ir_node *block) {
223 ir_cdep *cdep = find_cdep(block);
225 return cdep != NULL && cdep->next == NULL ? cdep->node : NULL;
228 /* Check if the given block is control dependent of more than one node. */
229 int has_multiple_cdep(const ir_node *block) {
230 ir_cdep *cdep = find_cdep(block);
232 return cdep != NULL && cdep->next != NULL;