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.
39 static int cmp_edge(const void *a, const void *b, size_t sz)
41 const dfs_edge_t *p = a;
42 const dfs_edge_t *q = b;
45 return !(p->src == q->src && p->tgt == q->tgt);
48 static int cmp_node(const void *a, const void *b, size_t sz)
50 const dfs_node_t *p = a;
51 const dfs_node_t *q = b;
54 return p->node != q->node;
57 #define get_node(dfs, node) _dfs_get_node(dfs, node)
59 static dfs_edge_t *get_edge(const dfs_t *self, void *src, void *tgt)
61 unsigned hash = HASH_COMBINE(HASH_PTR(src), HASH_PTR(tgt));
68 return set_insert(self->edges, &templ, sizeof(templ), hash);
71 static void dfs_perform(dfs_t *dfs, void *n, void *anc)
73 dfs_node_t *node = get_node(dfs, n);
76 assert(node->visited == 0);
81 node->pre_num = dfs->pre_num++;
82 node->max_pre_num = node->pre_num;
84 dfs->graph_impl->grow_succs(dfs->graph, n, &dfs->obst);
85 obstack_ptr_grow(&dfs->obst, NULL);
86 succs = obstack_finish(&dfs->obst);
88 for (iter = succs; *iter; ++iter) {
92 dfs_node_t *child = get_node(dfs, p);
94 /* create the edge object */
95 dfs_edge_t *edge = get_edge(dfs, n, p);
100 dfs_perform(dfs, p, node);
102 /* get the maximum pre num of the subtree. needed for ancestor determination. */
103 node->max_pre_num = MAX(node->max_pre_num, child->max_pre_num);
106 node->post_num = dfs->post_num++;
107 obstack_free(&dfs->obst, succs);
110 static void classify_edges(dfs_t *dfs)
114 foreach_set (dfs->edges, edge) {
115 dfs_node_t *src = edge->s;
116 dfs_node_t *tgt = edge->t;
118 if (tgt->ancestor == src)
119 edge->kind = DFS_EDGE_ANC;
120 else if (_dfs_int_is_ancestor(tgt, src))
121 edge->kind = DFS_EDGE_BACK;
122 else if (_dfs_int_is_ancestor(src, tgt))
123 edge->kind = DFS_EDGE_FWD;
125 edge->kind = DFS_EDGE_CROSS;
129 dfs_edge_kind_t dfs_get_edge_kind(const dfs_t *dfs, void *a, void *b)
131 if (!dfs->edges_classified) {
132 dfs_t *urg = (dfs_t *) dfs;
134 urg->edges_classified = 1;
136 return get_edge(dfs, a, b)->kind;
139 dfs_t *dfs_new(const absgraph_t *graph_impl, void *graph_self)
141 dfs_t *res = xmalloc(sizeof(res[0]));
144 res->graph_impl = graph_impl;
145 res->graph = graph_self;
146 res->nodes = new_set(cmp_node, 64);
147 res->edges = new_set(cmp_edge, 128);
151 res->edges_classified = 0;
153 obstack_init(&res->obst);
155 dfs_perform(res, graph_impl->get_root(graph_self), NULL);
158 res->pre_order = xmalloc(res->pre_num * sizeof(res->pre_order));
159 res->post_order = xmalloc(res->pre_num * sizeof(res->post_order));
160 foreach_set (res->nodes, node) {
161 res->pre_order[node->pre_num] = node;
162 res->post_order[node->post_num] = node;
168 void dfs_free(dfs_t *dfs)
172 xfree(dfs->pre_order);
173 xfree(dfs->post_order);
177 void dfs_dump(const dfs_t *dfs, FILE *file)
182 ir_fprintf(file, "digraph G {\n");
183 foreach_set (dfs->nodes, node) {
184 ir_fprintf(file, "\tn%d [shape=box,label=\"%+F\\l%d/%d %d\"];\n",
185 node->pre_num, node->node, node->pre_num, node->post_num, node->max_pre_num);
189 foreach_set (dfs->edges, edge) {
190 dfs_node_t *src = edge->s;
191 dfs_node_t *tgt = edge->t;
192 const char *s, *color;
194 #define XXX(e) case DFS_EDGE_ ## e: s = #e; break
195 switch (edge->kind) {
205 #define XXX(e) case DFS_EDGE_ ## e
206 switch (edge->kind) {
207 XXX(ANC): color = "black"; break;
208 XXX(FWD): color = "blue"; break;
209 XXX(CROSS): color = "red"; break;
210 XXX(BACK): color = "darkviolet"; break;
211 default: color = "?";
215 ir_fprintf(file, "\tn%d -> n%d [label=\"%s\",color=\"%s\"];\n", src->pre_num, tgt->pre_num, s, color);
218 ir_fprintf(file, "}\n");