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 Compute heights of nodes inside basic blocks
23 * @author Sebastian Hack
39 #include "irphase_t.h"
40 #include "iredges_t.h"
53 static void *irn_height_init(ir_phase *phase, const ir_node *node)
55 irn_height_t *h = (irn_height_t*) phase_alloc(phase, sizeof(*h));
57 memset(h, 0, sizeof(*h));
61 static void *irn_height_reinit(ir_phase *phase, const ir_node *node,
64 irn_height_t *h = (irn_height_t*) old_data;
67 memset(h, 0, sizeof(*h));
71 static void height_dump_cb(void *data, FILE *f, const ir_node *irn)
73 ir_heights_t *heights = (ir_heights_t*) data;
74 irn_height_t *h = (irn_height_t*) phase_get_irn_data(&heights->phase, irn);
77 fprintf(f, "height: %u\n", h->height);
81 * Check, if we can reach a target node from a given node inside one basic block.
82 * @param h The heights object.
83 * @param curr The current node from which we tried to reach the other one.
84 * @param tgt The node we try to reach.
85 * @return 1, one of tgt can be reached from curr, 0 else.
87 static bool search(const ir_heights_t *h, const ir_node *curr,
94 /* if the current node is the one we were looking for, we're done. */
98 /* If we are in another block or at a phi we won't find our target. */
99 if (get_nodes_block(curr) != get_nodes_block(tgt))
104 /* Check, if we have already been here. Coming more often won't help :-) */
105 h_curr = (irn_height_t*) phase_get_irn_data(&h->phase, curr);
106 if (h_curr->visited >= h->visited)
109 /* If we are too deep into the DAG we won't find the target either. */
110 h_tgt = (irn_height_t*) phase_get_irn_data(&h->phase, tgt);
111 if (h_curr->height > h_tgt->height)
114 /* Mark this place as visited. */
115 h_curr->visited = h->visited;
117 /* Start a search from this node. */
118 for (i = 0, n = get_irn_ins_or_deps(curr); i < n; ++i) {
119 ir_node *op = get_irn_in_or_dep(curr, i);
120 if (search(h, op, tgt))
128 * Check, if one node can be reached from another one, according to data
131 int heights_reachable_in_block(ir_heights_t *h, const ir_node *n,
135 irn_height_t *hn = (irn_height_t*) phase_get_irn_data(&h->phase, n);
136 irn_height_t *hm = (irn_height_t*) phase_get_irn_data(&h->phase, m);
138 assert(get_nodes_block(n) == get_nodes_block(m));
139 assert(hn != NULL && hm != NULL);
141 if (hn->height <= hm->height) {
143 res = search(h, n, m);
150 * Compute the height of a node in a block.
151 * @param h The heights object.
152 * @param irn The node.
153 * @param bl The block.
155 static unsigned compute_height(ir_heights_t *h, ir_node *irn, const ir_node *bl)
157 irn_height_t *ih = (irn_height_t*) phase_get_or_set_irn_data(&h->phase, irn);
159 const ir_edge_t *edge;
161 /* bail out if we already visited that node. */
162 if (ih->visited >= h->visited)
165 ih->visited = h->visited;
168 foreach_out_edge(irn, edge) {
169 ir_node *dep = get_edge_src_irn(edge);
171 if (!is_Block(dep) && !is_Phi(dep) && get_nodes_block(dep) == bl) {
172 unsigned dep_height = compute_height(h, dep, bl);
173 ih->height = MAX(ih->height, dep_height);
179 foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
180 ir_node *dep = get_edge_src_irn(edge);
182 assert(!is_Phi(dep));
183 if (!is_Block(dep) && get_nodes_block(dep) == bl) {
184 unsigned dep_height = compute_height(h, dep, bl);
185 ih->height = MAX(ih->height, dep_height);
194 static unsigned compute_heights_in_block(ir_node *bl, ir_heights_t *h)
197 const ir_edge_t *edge;
201 foreach_out_edge(bl, edge) {
202 ir_node *dep = get_edge_src_irn(edge);
203 int curh = compute_height(h, dep, bl);
205 max_height = MAX(curh, max_height);
208 foreach_out_edge_kind(bl, edge, EDGE_KIND_DEP) {
209 ir_node *dep = get_edge_src_irn(edge);
210 int curh = compute_height(h, dep, bl);
212 max_height = MAX(curh, max_height);
218 static void compute_heights_in_block_walker(ir_node *block, void *data)
220 ir_heights_t *h = (ir_heights_t*) data;
221 compute_heights_in_block(block, h);
224 unsigned get_irn_height(const ir_heights_t *heights, const ir_node *irn)
226 const irn_height_t *h = (irn_height_t*) phase_get_irn_data(&heights->phase, irn);
227 assert(h && "No height information for node");
231 unsigned heights_recompute_block(ir_heights_t *h, ir_node *block)
233 const ir_edge_t *edge;
235 edges_assure(phase_get_irg(&h->phase));
237 /* reset phase data for all nodes in the block */
238 foreach_out_edge(block, edge) {
239 ir_node *irn = get_edge_src_irn(edge);
240 irn_height_t *ih = (irn_height_t*) phase_get_irn_data(&h->phase, irn);
241 memset(ih, 0, sizeof(*ih));
245 return compute_heights_in_block(block, h);
248 void heights_recompute(ir_heights_t *h)
250 ir_graph *irg = phase_get_irg(&h->phase);
253 phase_reinit_irn_data(&h->phase, irn_height_reinit);
255 irg_block_walk_graph(irg, compute_heights_in_block_walker, NULL, h);
258 ir_heights_t *heights_new(ir_graph *irg)
260 ir_heights_t *res = XMALLOC(ir_heights_t);
261 phase_init(&res->phase, irg, irn_height_init);
262 res->dump_handle = dump_add_node_info_callback(height_dump_cb, res);
263 heights_recompute(res);
268 void heights_free(ir_heights_t *h)
270 phase_deinit(&h->phase);
271 dump_remove_node_info_callback(h->dump_handle);