2 * Copyright (C) 1995-2011 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 and access out edges (also called def-use edges).
23 * @author Goetz Lindenmaier, Michael Beck
33 #include "irgraph_t.h"
41 int get_irn_n_outs(const ir_node *node)
43 assert(node->kind == k_ir_node);
44 assert(node->out_valid);
45 /* we misuse the first for the size info of the out array */
46 return node->out[0].pos;
49 ir_node *get_irn_out(const ir_node *def, int pos)
51 assert(pos >= 0 && pos < get_irn_n_outs(def));
52 assert(def->out_valid);
53 return def->out[pos+1].use;
56 ir_node *get_irn_out_ex(const ir_node *def, int pos, int *in_pos)
58 assert(pos >= 0 && pos < get_irn_n_outs(def));
59 assert(def->out_valid);
60 *in_pos = def->out[pos+1].pos;
61 return def->out[pos+1].use;
64 void set_irn_out(ir_node *def, int pos, ir_node *use, int in_pos)
67 assert(pos >= 0 && pos < get_irn_n_outs(def));
68 assert(def->out_valid);
69 def->out[pos+1].use = use;
70 def->out[pos+1].pos = in_pos;
73 int get_Block_n_cfg_outs(const ir_node *bl)
76 assert(bl->out_valid);
78 for (int i = 1; i <= bl->out[0].pos; ++i) {
79 const ir_node *succ = bl->out[i].use;
80 if (get_irn_mode(succ) == mode_X && !is_End(succ) && !is_Bad(succ))
81 n_cfg_outs += succ->out[0].pos;
86 int get_Block_n_cfg_outs_ka(const ir_node *bl)
89 assert(bl->out_valid);
91 for (int i = 1; i <= bl->out[0].pos; ++i) {
92 const ir_node *succ = bl->out[i].use;
93 if (get_irn_mode(succ) == mode_X) {
97 /* ignore End if we are in the Endblock */
98 if (get_nodes_block(succ) == bl)
100 else /* count Keep-alive as one */
103 n_cfg_outs += succ->out[0].pos;
109 ir_node *get_Block_cfg_out(const ir_node *bl, int pos)
111 assert(is_Block(bl));
112 assert(bl->out_valid);
113 for (int i = 1; i <= bl->out[0].pos; ++i) {
114 const ir_node *succ = bl->out[i].use;
115 if (get_irn_mode(succ) == mode_X && !is_End(succ) && !is_Bad(succ)) {
116 int n_outs = succ->out[0].pos;
118 return succ->out[pos + 1].use;
126 ir_node *get_Block_cfg_out_ka(const ir_node *bl, int pos)
128 assert(is_Block(bl));
129 assert(bl->out_valid);
130 for (int i = 1; i <= bl->out[0].pos; ++i) {
131 const ir_node *succ = bl->out[i].use;
132 if (get_irn_mode(succ) == mode_X) {
136 ir_node *end_bl = get_nodes_block(succ);
138 /* ignore End if we are in the Endblock */
142 /* handle keep-alive here: return the Endblock instead of the End node */
147 int n_outs = succ->out[0].pos;
149 return succ->out[pos + 1].use;
158 static void irg_out_walk_2(ir_node *node, irg_walk_func *pre,
159 irg_walk_func *post, void *env)
161 assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
163 set_irn_visited(node, get_irg_visited(current_ir_graph));
165 if (pre) pre(node, env);
167 int n = get_irn_n_outs(node);
168 for (int i = 0; i < n; ++i) {
169 ir_node *succ = get_irn_out(node, i);
170 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
171 irg_out_walk_2(succ, pre, post, env);
174 if (post) post(node, env);
177 void irg_out_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
181 ir_graph *irg = get_irn_irg(node);
182 if (irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_OUTS)) {
183 inc_irg_visited(irg);
184 irg_out_walk_2(node, pre, post, env);
188 static void irg_out_block_walk2(ir_node *bl, irg_walk_func *pre,
189 irg_walk_func *post, void *env)
191 if (Block_block_visited(bl))
194 mark_Block_block_visited(bl);
199 int n = get_Block_n_cfg_outs(bl);
200 for (int i = 0; i < n; ++i) {
201 /* find the corresponding predecessor block. */
202 ir_node *pred = get_Block_cfg_out(bl, i);
204 irg_out_block_walk2(pred, pre, post, env);
211 void irg_out_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
214 ir_graph *irg = get_irn_irg(node);
215 assert(is_Block(node) || (get_irn_mode(node) == mode_X));
217 ir_graph *rem = current_ir_graph;
218 current_ir_graph = irg;
220 inc_irg_block_visited(irg);
222 if (get_irn_mode(node) == mode_X) {
223 int n = get_irn_n_outs(node);
224 for (int i = 0; i < n; ++i) {
225 ir_node *succ = get_irn_out(node, i);
226 irg_out_block_walk2(succ, pre, post, env);
229 irg_out_block_walk2(node, pre, post, env);
232 current_ir_graph = rem;
235 /*--------------------------------------------------------------------*/
236 /** Building and Removing the out datastructure **/
238 /** The outs of a graph are allocated in a single, large array. **/
239 /** This allows to allocate and deallocate the memory for the outs **/
240 /** on demand. The large array is separated into many small ones **/
241 /** for each node. Only a single field to reference the out array **/
242 /** is stored in each node and a field referencing the large out **/
243 /** array in irgraph. The 0 field of each out array contains the **/
244 /** size of this array. This saves memory in the irnodes themselves.**/
245 /** The construction does two passes over the graph. The first pass **/
246 /** counts the overall number of outs and the outs of each node. It **/
247 /** stores the outs of each node in the out reference of the node. **/
248 /** Then the large array is allocated. The second iteration chops **/
249 /** the large array into smaller parts, sets the out edges and **/
250 /** recounts the out edges. **/
251 /** Removes Tuple nodes! **/
252 /*--------------------------------------------------------------------*/
255 /** Returns the amount of out edges for not yet visited successors. */
256 static int _count_outs(ir_node *n)
259 n->out = (ir_def_use_edge*) INT_TO_PTR(1); /* Space for array size. */
261 int start = is_Block(n) ? 0 : -1;
262 int irn_arity = get_irn_arity(n);
263 int res = irn_arity - start + 1; /* --1 or --0; 1 for array size. */
265 for (int i = start; i < irn_arity; ++i) {
266 /* Optimize Tuples. They annoy if walking the cfg. */
267 ir_node *pred = get_irn_n(n, i);
268 ir_node *skipped_pred = skip_Tuple(pred);
270 if (skipped_pred != pred) {
271 set_irn_n(n, i, skipped_pred);
274 /* count Def-Use edges for predecessors */
275 if (!irn_visited(skipped_pred))
276 res += _count_outs(skipped_pred);
278 /*count my Def-Use edges */
279 skipped_pred->out = (ir_def_use_edge*) INT_TO_PTR(PTR_TO_INT(skipped_pred->out) + 1);
285 /** Returns the amount of out edges for not yet visited successors.
286 * This version handles some special nodes like irg_frame, irg_args etc.
288 static int count_outs(ir_graph *irg)
290 inc_irg_visited(irg);
291 int res = _count_outs(get_irg_end(irg));
293 /* Now handle anchored nodes. We need the out count of those
294 even if they are not visible. */
295 for (int i = anchor_last; i >= anchor_first; --i) {
296 ir_node *n = get_irg_anchor(irg, i);
297 if (!irn_visited_else_mark(n)) {
298 n->out = (ir_def_use_edge*) INT_TO_PTR(1);
306 * Enter memory for the outs to a node.
308 * @param use current node
309 * @param free current free address in the chunk allocated for the outs
311 * @return The next free address
313 static ir_def_use_edge *_set_out_edges(ir_node *use, ir_def_use_edge *free)
315 mark_irn_visited(use);
317 /* Allocate my array */
318 size_t n_outs = PTR_TO_INT(use->out);
322 #endif /* defined DEBUG_libfirm */
324 /* We count the successors again, the space will be sufficient.
325 We use this counter to remember the position for the next back
329 int start = is_Block(use) ? 0 : -1;
330 int irn_arity = get_irn_arity(use);
332 for (int i = start; i < irn_arity; ++i) {
333 ir_node *def = get_irn_n(use, i);
336 if (!irn_visited(def))
337 free = _set_out_edges(def, free);
339 /* Remember this Def-Use edge */
340 int pos = def->out[0].pos + 1;
341 def->out[pos].use = use;
342 def->out[pos].pos = i;
344 /* increase the number of Def-Use edges so far */
345 def->out[0].pos = pos;
351 * Enter memory for the outs to a node. Handles special nodes
353 * @param irg the graph
354 * @param free current free address in the chunk allocated for the outs
356 * @return The next free address
358 static ir_def_use_edge *set_out_edges(ir_graph *irg, ir_def_use_edge *free)
360 inc_irg_visited(irg);
361 free = _set_out_edges(get_irg_end(irg), free);
363 /* handle anchored nodes */
364 for (int i = anchor_last; i >= anchor_first; --i) {
365 ir_node *n = get_irg_anchor(irg, i);
366 if (!irn_visited_else_mark(n)) {
367 size_t n_outs = PTR_TO_INT(n->out);
379 void compute_irg_outs(ir_graph *irg)
382 ir_def_use_edge *end = NULL; /* Only for debugging */
384 /* Update graph state */
385 assert(get_irg_phase_state(irg) != phase_building);
389 /* This first iteration counts the overall number of out edges and the
390 number of out edges for each node. */
391 n_out_edges = count_outs(irg);
393 /* allocate memory for all out edges. */
394 irg->outs = XMALLOCNZ(ir_def_use_edge, n_out_edges);
396 irg->n_outs = n_out_edges;
399 /* The second iteration splits the irg->outs array into smaller arrays
400 for each node and writes the back edges into this array. */
401 end = set_out_edges(irg, irg->outs);
403 /* Check how much memory we have used */
404 assert (end == (irg->outs + n_out_edges));
406 add_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_OUTS);
409 void assure_irg_outs(ir_graph *irg)
411 if (! irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_OUTS))
412 compute_irg_outs(irg);
416 /** Clear the outs of a node */
417 static void reset_outs(ir_node *node, void *unused)
425 void free_irg_outs(ir_graph *irg)
427 if (irg->outs != NULL) {
429 memset(irg->outs, 0, irg->n_outs);
437 /* when debugging, *always* reset all nodes' outs! irg->outs might
438 have been lying to us */
439 irg_walk_graph (irg, reset_outs, NULL, NULL);