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 ir_cdep *find_cdep(const ir_node *block)
48 return (ir_cdep*) pmap_get(cdep_data->cdep_map, block);
51 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)
62 ir_cdep *dep = find_cdep(node);
65 ir_cdep *newdep = OALLOC(&cdep_data->obst, ir_cdep);
67 newdep->node = dep_on;
69 pmap_insert(cdep_data->cdep_map, node, newdep);
74 if (dep->node == dep_on) return;
75 if (dep->next == NULL) break;
78 newdep = OALLOC(&cdep_data->obst, ir_cdep);
79 newdep->node = dep_on;
85 typedef struct cdep_env {
91 * Pre-block-walker: calculate the control dependence
93 static void cdep_pre(ir_node *node, void *ctx)
95 cdep_env *env = (cdep_env*) ctx;
99 * start and end block have no control dependency
101 if (node == env->start_block) return;
102 if (node == env->end_block) return;
104 for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
105 ir_node *pred = get_Block_cfgpred_block(node, i);
109 if (is_Bad(pred)) continue;
111 pdom = get_Block_ipostdom(pred);
112 for (dependee = node; dependee != pdom; dependee = get_Block_ipostdom(dependee)) {
113 assert(!is_Bad(pdom));
114 add_cdep(dependee, pred);
121 * A block edge hook: add all cdep edges of block.
123 static int cdep_edge_hook(FILE *F, ir_node *block)
127 for (cd = find_cdep(block); cd != NULL; cd = cd->next) {
130 "edge:{sourcename:\"n%ld\" targetname:\"n%ld\" "
131 "linestyle:dashed color:gold}\n",
132 get_irn_node_nr(block), get_irn_node_nr(cd->node)
139 void compute_cdep(ir_graph *irg)
145 cdep_data = XMALLOC(cdep_info);
146 obstack_init(&cdep_data->obst);
148 cdep_data->cdep_map = pmap_create();
150 assure_postdoms(irg);
152 /* we must temporary change the post dominator relation:
153 the ipdom of the startblock is the end block.
154 Firm does NOT add the phantom edge from Start to End.
156 env.start_block = get_irg_start_block(irg);
157 env.end_block = get_irg_end_block(irg);
159 rem = get_Block_ipostdom(env.start_block);
160 set_Block_ipostdom(env.start_block, env.end_block);
162 irg_block_walk_graph(irg, cdep_pre, NULL, &env);
165 set_dump_block_edge_hook(cdep_edge_hook);
166 dump_ir_block_graph(irg, "_cdep");
167 set_dump_block_edge_hook(NULL);
169 (void) cdep_edge_hook;
172 /* restore the post dominator relation */
173 set_Block_ipostdom(env.start_block, rem);
176 void free_cdep(ir_graph *irg)
179 if (cdep_data != NULL) {
180 pmap_destroy(cdep_data->cdep_map);
181 obstack_free(&cdep_data->obst, NULL);
187 int is_cdep_on(const ir_node *dependee, const ir_node *candidate)
191 for (dep = find_cdep(dependee); dep != NULL; dep = dep->next) {
192 if (dep->node == candidate) return 1;
197 ir_node *get_unique_cdep(const ir_node *block)
199 ir_cdep *cdep = find_cdep(block);
201 return cdep != NULL && cdep->next == NULL ? cdep->node : NULL;
204 int has_multiple_cdep(const ir_node *block)
206 ir_cdep *cdep = find_cdep(block);
208 return cdep != NULL && cdep->next != NULL;