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_node *(get_cdep_node)(const ir_cdep *cdep)
48 return _get_cdep_node(cdep);
51 ir_cdep *(get_cdep_next)(const ir_cdep *cdep)
53 return _get_cdep_next(cdep);
56 /* Return a list of all control dependences of a block. */
57 ir_cdep *find_cdep(const ir_node *block)
59 assert(is_Block(block));
60 return (ir_cdep*) pmap_get(cdep_data->cdep_map, block);
63 void exchange_cdep(ir_node *old, const ir_node *nw)
65 ir_cdep *cdep = find_cdep(nw);
66 assert(is_Block(old));
67 pmap_insert(cdep_data->cdep_map, old, cdep);
71 * Adds a control dependence from node to dep_on.
73 static void add_cdep(ir_node *node, ir_node *dep_on)
75 ir_cdep *dep = find_cdep(node);
77 assert(is_Block(dep_on));
79 ir_cdep *newdep = OALLOC(&cdep_data->obst, ir_cdep);
81 newdep->node = dep_on;
83 pmap_insert(cdep_data->cdep_map, node, newdep);
88 if (get_cdep_node(dep) == dep_on) return;
89 if (dep->next == NULL) break;
92 newdep = OALLOC(&cdep_data->obst, ir_cdep);
93 newdep->node = dep_on;
99 typedef struct cdep_env {
100 ir_node *start_block;
105 * Pre-block-walker: calculate the control dependence
107 static void cdep_pre(ir_node *node, void *ctx)
109 cdep_env *env = (cdep_env*) ctx;
113 * start and end block have no control dependency
115 if (node == env->start_block) return;
116 if (node == env->end_block) return;
118 for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
119 ir_node *pred = get_Block_cfgpred_block(node, i);
123 if (is_Bad(pred)) continue;
125 pdom = get_Block_ipostdom(pred);
126 for (dependee = node; dependee != pdom; dependee = get_Block_ipostdom(dependee)) {
127 assert(!is_Bad(pdom));
128 add_cdep(dependee, pred);
135 * A block edge hook: add all cdep edges of block.
137 static int cdep_edge_hook(FILE *F, ir_node *block)
141 for (cd = find_cdep(block); cd != NULL; cd = cd->next) {
144 "edge:{sourcename:\"n%ld\" targetname:\"n%ld\" "
145 "linestyle:dashed color:gold}\n",
146 get_irn_node_nr(block), get_irn_node_nr(cd->node)
153 void compute_cdep(ir_graph *irg)
159 cdep_data = XMALLOC(cdep_info);
160 obstack_init(&cdep_data->obst);
162 cdep_data->cdep_map = pmap_create();
164 assure_postdoms(irg);
166 /* we must temporary change the post dominator relation:
167 the ipdom of the startblock is the end block.
168 Firm does NOT add the phantom edge from Start to End.
170 env.start_block = get_irg_start_block(irg);
171 env.end_block = get_irg_end_block(irg);
173 rem = get_Block_ipostdom(env.start_block);
174 set_Block_ipostdom(env.start_block, env.end_block);
176 irg_block_walk_graph(irg, cdep_pre, NULL, &env);
179 set_dump_block_edge_hook(cdep_edge_hook);
180 dump_ir_block_graph(irg, "_cdep");
181 set_dump_block_edge_hook(NULL);
183 (void) cdep_edge_hook;
186 /* restore the post dominator relation */
187 set_Block_ipostdom(env.start_block, rem);
190 void free_cdep(ir_graph *irg)
193 if (cdep_data != NULL) {
194 pmap_destroy(cdep_data->cdep_map);
195 obstack_free(&cdep_data->obst, NULL);
201 int is_cdep_on(const ir_node *dependee, const ir_node *candidate)
205 for (dep = find_cdep(dependee); dep != NULL; dep = dep->next) {
206 if (get_cdep_node(dep) == candidate) return 1;
211 ir_node *get_unique_cdep(const ir_node *block)
213 ir_cdep *cdep = find_cdep(block);
215 return cdep != NULL && cdep->next == NULL ? get_cdep_node(cdep) : NULL;
218 int has_multiple_cdep(const ir_node *block)
220 ir_cdep *cdep = find_cdep(block);
222 return cdep != NULL && cdep->next != NULL;