2 * Copyright (C) 1995-2007 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 * @author Sebastian Hack
27 * Simple depth first search on CFGs.
42 static int cmp_edge(const void *a, const void *b, size_t sz)
44 const dfs_edge_t *p = a;
45 const dfs_edge_t *q = b;
48 return !(p->src == q->src && p->tgt == q->tgt);
51 static int cmp_node(const void *a, const void *b, size_t sz)
53 const dfs_node_t *p = a;
54 const dfs_node_t *q = b;
57 return p->node != q->node;
60 #define get_node(dfs, node) _dfs_get_node(dfs, node)
62 static dfs_edge_t *get_edge(const dfs_t *self, void *src, void *tgt)
64 unsigned hash = HASH_COMBINE(HASH_PTR(src), HASH_PTR(tgt));
71 return set_insert(self->edges, &templ, sizeof(templ), hash);
74 static void dfs_perform(dfs_t *dfs, void *n, void *anc, int level)
76 dfs_node_t *node = get_node(dfs, n);
79 assert(node->visited == 0);
84 node->pre_num = dfs->pre_num++;
85 node->max_pre_num = node->pre_num;
88 dfs->graph_impl->grow_succs(dfs->graph, n, &dfs->obst);
89 obstack_ptr_grow(&dfs->obst, NULL);
90 succs = obstack_finish(&dfs->obst);
92 for (iter = succs; *iter; ++iter) {
96 dfs_node_t *child = get_node(dfs, p);
98 /* create the edge object */
99 dfs_edge_t *edge = get_edge(dfs, n, p);
104 dfs_perform(dfs, p, node, level + 1);
106 /* get the maximum pre num of the subtree. needed for ancestor determination. */
107 node->max_pre_num = MAX(node->max_pre_num, child->max_pre_num);
110 node->post_num = dfs->post_num++;
111 obstack_free(&dfs->obst, succs);
114 static void classify_edges(dfs_t *dfs)
118 foreach_set (dfs->edges, edge) {
119 dfs_node_t *src = edge->s;
120 dfs_node_t *tgt = edge->t;
122 if (tgt->ancestor == src)
123 edge->kind = DFS_EDGE_ANC;
124 else if (_dfs_int_is_ancestor(tgt, src))
125 edge->kind = DFS_EDGE_BACK;
126 else if (_dfs_int_is_ancestor(src, tgt))
127 edge->kind = DFS_EDGE_FWD;
129 edge->kind = DFS_EDGE_CROSS;
133 dfs_edge_kind_t dfs_get_edge_kind(const dfs_t *dfs, void *a, void *b)
135 if (!dfs->edges_classified) {
136 dfs_t *urg = (dfs_t *) dfs;
138 urg->edges_classified = 1;
140 return get_edge(dfs, a, b)->kind;
143 dfs_t *dfs_new(const absgraph_t *graph_impl, void *graph_self)
145 dfs_t *res = xmalloc(sizeof(res[0]));
148 res->graph_impl = graph_impl;
149 res->graph = graph_self;
150 res->nodes = new_set(cmp_node, 64);
151 res->edges = new_set(cmp_edge, 128);
155 res->edges_classified = 0;
157 obstack_init(&res->obst);
159 dfs_perform(res, graph_impl->get_root(graph_self), NULL, 0);
162 res->pre_order = xmalloc(res->pre_num * sizeof(res->pre_order));
163 res->post_order = xmalloc(res->pre_num * sizeof(res->post_order));
164 foreach_set (res->nodes, node) {
165 res->pre_order[node->pre_num] = node;
166 res->post_order[node->post_num] = node;
172 void dfs_free(dfs_t *dfs)
176 xfree(dfs->pre_order);
177 xfree(dfs->post_order);
181 static void dfs_dump_edge(const dfs_edge_t *edge, FILE *file)
183 dfs_node_t *src = edge->s;
184 dfs_node_t *tgt = edge->t;
185 const char *s, *style;
188 #define XXX(e) case DFS_EDGE_ ## e: s = #e; break
189 switch (edge->kind) {
197 weight = edge->kind == DFS_EDGE_BACK ? 1 : 1000;
198 style = edge->kind == DFS_EDGE_BACK ? "dashed" : "solid";
200 ir_fprintf(file, "\tn%d -> n%d [label=\"%s\",style=\"%s\",weight=\"%d\"];\n", src->pre_num, tgt->pre_num, s, style, weight);
203 static int node_level_cmp(const void *a, const void *b)
205 const dfs_node_t *p = *(const dfs_node_t **) a;
206 const dfs_node_t *q = *(const dfs_node_t **) b;
208 if (p->level == q->level)
209 return p->pre_num - q->pre_num;
210 return p->level - q->level;
213 void dfs_dump(const dfs_t *dfs, FILE *file)
215 dfs_node_t **nodes = xmalloc(dfs->pre_num * sizeof(nodes[0]));
220 ir_fprintf(file, "digraph G {\nranksep=0.5\n");
221 foreach_set (dfs->nodes, node) {
225 qsort(nodes, n, sizeof(nodes[0]), node_level_cmp);
229 int level = nodes[i]->level;
231 ir_fprintf(file, "\t{ rank = same; ");
232 for (; i < n && nodes[i]->level == level; ++i)
233 ir_fprintf(file, "n%d;", nodes[i]->pre_num);
234 ir_fprintf(file, "}\n");
239 for (i = 0; i < n; ++i) {
240 dfs_node_t *node = nodes[i];
241 ir_fprintf(file, "\tn%d [label=\"%d\"]\n", node->pre_num, get_Block_dom_tree_pre_num(node->node));
243 ir_fprintf(file, "\tn%d [shape=box,label=\"%+F\\l%d %d/%d %d\"];\n",
244 node->pre_num, node->node, get_Block_dom_tree_pre_num(node->node),
245 node->pre_num, node->post_num, node->max_pre_num);
249 foreach_set (dfs->edges, edge)
250 dfs_dump_edge(edge, file);
252 ir_fprintf(file, "}\n");