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
34 #include "irgraph_t.h"
42 /* Note: ir_node.out_valid and ir_graph.n_outs are only present when DEBUG_libfirm is defined */
43 /* Accesses to out_valid and n_outs are fenced out to avoid breakage
44 when compiling with neither DEBUG_libfirm or NDEBUG defined */
45 #endif /* defined DEBUG_libfirm */
47 /*--------------------------------------------------------------------*/
48 /** Accessing the out datastructures **/
49 /*--------------------------------------------------------------------*/
52 /** Clear the outs of a node */
53 static void reset_outs(ir_node *node, void *unused)
61 int get_irn_outs_computed(const ir_node *node)
63 return node->out != NULL;
66 /* returns the number of successors of the node: */
67 int get_irn_n_outs(const ir_node *node)
69 assert(node && node->kind == k_ir_node);
71 /* assert(node->out_valid); */
72 #endif /* defined DEBUG_libfirm */
73 /* we misuse the first for the size info of the out array */
74 return node->out[0].pos;
77 /* Access successor n */
78 ir_node *get_irn_out(const ir_node *def, int pos)
80 assert(pos >= 0 && pos < get_irn_n_outs(def));
82 /* assert(def->out_valid); */
83 #endif /* defined DEBUG_libfirm */
84 return def->out[pos+1].use;
87 /* Access successor n */
88 ir_node *get_irn_out_ex(const ir_node *def, int pos, int *in_pos)
90 assert(pos >= 0 && pos < get_irn_n_outs(def));
92 /* assert(def->out_valid); */
93 #endif /* defined DEBUG_libfirm */
94 *in_pos = def->out[pos+1].pos;
95 return def->out[pos+1].use;
98 void set_irn_out(ir_node *def, int pos, ir_node *use, int in_pos)
101 assert(pos >= 0 && pos < get_irn_n_outs(def));
103 def->out_valid = 1; /* assume that this function is used correctly */
104 #endif /* defined DEBUG_libfirm */
105 def->out[pos+1].use = use;
106 def->out[pos+1].pos = in_pos;
109 /* Return the number of control flow successors, ignore keep-alives. */
110 int get_Block_n_cfg_outs(const ir_node *bl)
112 int i, n_cfg_outs = 0;
113 assert(bl && is_Block(bl));
115 assert(bl->out_valid);
116 #endif /* defined DEBUG_libfirm */
117 for (i = 1; i <= bl->out[0].pos; ++i) {
118 ir_node *succ = bl->out[i].use;
119 if (get_irn_mode(succ) == mode_X && !is_End(succ))
120 n_cfg_outs += succ->out[0].pos;
125 /* Return the number of control flow successors, honor keep-alives. */
126 int get_Block_n_cfg_outs_ka(const ir_node *bl)
128 int i, n_cfg_outs = 0;
129 assert(bl && is_Block(bl));
131 assert(bl->out_valid);
132 #endif /* defined DEBUG_libfirm */
133 for (i = 1; i <= bl->out[0].pos; ++i) {
134 ir_node *succ = bl->out[i].use;
135 if (get_irn_mode(succ) == mode_X) {
138 /* ignore End if we are in the Endblock */
139 if (get_nodes_block(succ) == bl)
141 else /* count Keep-alive as one */
144 n_cfg_outs += succ->out[0].pos;
150 /* Access predecessor n, ignore keep-alives. */
151 ir_node *get_Block_cfg_out(const ir_node *bl, int pos)
154 assert(bl && is_Block(bl));
156 assert(bl->out_valid);
157 #endif /* defined DEBUG_libfirm */
158 for (i = 1; i <= bl->out[0].pos; ++i) {
159 ir_node *succ = bl->out[i].use;
160 if (get_irn_mode(succ) == mode_X && !is_End(succ)) {
161 int n_outs = succ->out[0].pos;
163 return succ->out[pos + 1].use;
171 /* Access predecessor n, honor keep-alives. */
172 ir_node *get_Block_cfg_out_ka(const ir_node *bl, int pos)
175 assert(bl && is_Block(bl));
177 assert (bl->out_valid);
178 #endif /* defined DEBUG_libfirm */
179 for (i = 1; i <= bl->out[0].pos; ++i) {
180 ir_node *succ = bl->out[i].use;
181 if (get_irn_mode(succ) == mode_X) {
183 ir_node *end_bl = get_nodes_block(succ);
185 /* ignore End if we are in the Endblock */
189 /* handle keep-alive here: return the Endblock instead of the End node */
194 n_outs = succ->out[0].pos;
196 return succ->out[pos + 1].use;
205 static void irg_out_walk_2(ir_node *node, irg_walk_func *pre,
206 irg_walk_func *post, void *env)
212 assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
214 set_irn_visited(node, get_irg_visited(current_ir_graph));
216 if (pre) pre(node, env);
218 for (i = 0, n = get_irn_n_outs(node); i < n; ++i) {
219 succ = get_irn_out(node, i);
220 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
221 irg_out_walk_2(succ, pre, post, env);
224 if (post) post(node, env);
227 void irg_out_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
231 if (get_irg_outs_state(current_ir_graph) != outs_none) {
232 inc_irg_visited (current_ir_graph);
233 irg_out_walk_2(node, pre, post, env);
237 static void irg_out_block_walk2(ir_node *bl, irg_walk_func *pre,
238 irg_walk_func *post, void *env)
242 if (!Block_block_visited(bl)) {
243 mark_Block_block_visited(bl);
248 for (i = 0, n = get_Block_n_cfg_outs(bl); i < n; ++i) {
249 /* find the corresponding predecessor block. */
250 ir_node *pred = get_Block_cfg_out(bl, i);
252 irg_out_block_walk2(pred, pre, post, env);
260 /* Walks only over Block nodes in the graph. Has its own visited
261 flag, so that it can be interleaved with the other walker. */
262 void irg_out_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post,
266 assert(is_Block(node) || (get_irn_mode(node) == mode_X));
268 inc_irg_block_visited(current_ir_graph);
270 if (get_irn_mode(node) == mode_X) {
273 for (i = 0, n = get_irn_n_outs(node); i < n; ++i) {
274 ir_node *succ = get_irn_out(node, i);
275 irg_out_block_walk2(succ, pre, post, env);
279 irg_out_block_walk2(node, pre, post, env);
283 /*--------------------------------------------------------------------*/
284 /** Building and Removing the out datastructure **/
286 /** The outs of a graph are allocated in a single, large array. **/
287 /** This allows to allocate and deallocate the memory for the outs **/
288 /** on demand. The large array is separated into many small ones **/
289 /** for each node. Only a single field to reference the out array **/
290 /** is stored in each node and a field referencing the large out **/
291 /** array in irgraph. The 0 field of each out array contains the **/
292 /** size of this array. This saves memory in the irnodes themselves.**/
293 /** The construction does two passes over the graph. The first pass **/
294 /** counts the overall number of outs and the outs of each node. It **/
295 /** stores the outs of each node in the out reference of the node. **/
296 /** Then the large array is allocated. The second iteration chops **/
297 /** the large array into smaller parts, sets the out edges and **/
298 /** recounts the out edges. **/
299 /** Removes Tuple nodes! **/
300 /*--------------------------------------------------------------------*/
303 /** Returns the amount of out edges for not yet visited successors. */
304 static int _count_outs(ir_node *n)
306 int start, i, res, irn_arity;
309 n->out = (ir_def_use_edge*) INT_TO_PTR(1); /* Space for array size. */
311 start = is_Block(n) ? 0 : -1;
312 irn_arity = get_irn_arity(n);
313 res = irn_arity - start + 1; /* --1 or --0; 1 for array size. */
315 for (i = start; i < irn_arity; ++i) {
316 /* Optimize Tuples. They annoy if walking the cfg. */
317 ir_node *pred = get_irn_n(n, i);
318 ir_node *skipped_pred = skip_Tuple(pred);
320 if (skipped_pred != pred) {
321 set_irn_n(n, i, skipped_pred);
324 /* count Def-Use edges for predecessors */
325 if (!irn_visited(skipped_pred))
326 res += _count_outs(skipped_pred);
328 /*count my Def-Use edges */
329 skipped_pred->out = (ir_def_use_edge*) INT_TO_PTR(PTR_TO_INT(skipped_pred->out) + 1);
335 /** Returns the amount of out edges for not yet visited successors.
336 * This version handles some special nodes like irg_frame, irg_args etc.
338 static int count_outs(ir_graph *irg)
343 inc_irg_visited(irg);
344 res = _count_outs(get_irg_end(irg));
346 /* Now handle anchored nodes. We need the out count of those
347 even if they are not visible. */
348 for (i = anchor_last - 1; i >= 0; --i) {
349 n = get_irg_anchor(irg, i);
350 if (!irn_visited_else_mark(n)) {
351 n->out = (ir_def_use_edge*) INT_TO_PTR(1);
359 * Enter memory for the outs to a node.
361 * @param use current node
362 * @param free current free address in the chunk allocated for the outs
364 * @return The next free address
366 static ir_def_use_edge *_set_out_edges(ir_node *use, ir_def_use_edge *free)
368 int start, i, irn_arity, pos;
371 mark_irn_visited(use);
373 /* Allocate my array */
374 n_outs = PTR_TO_INT(use->out);
378 #endif /* defined DEBUG_libfirm */
380 /* We count the successors again, the space will be sufficient.
381 We use this counter to remember the position for the next back
385 start = is_Block(use) ? 0 : -1;
386 irn_arity = get_irn_arity(use);
388 for (i = start; i < irn_arity; ++i) {
389 ir_node *def = get_irn_n(use, i);
392 if (!irn_visited(def))
393 free = _set_out_edges(def, free);
395 /* Remember this Def-Use edge */
396 pos = def->out[0].pos + 1;
397 def->out[pos].use = use;
398 def->out[pos].pos = i;
400 /* increase the number of Def-Use edges so far */
401 def->out[0].pos = pos;
407 * Enter memory for the outs to a node. Handles special nodes
409 * @param irg the graph
410 * @param free current free address in the chunk allocated for the outs
412 * @return The next free address
414 static ir_def_use_edge *set_out_edges(ir_graph *irg, ir_def_use_edge *free)
419 inc_irg_visited(irg);
420 free = _set_out_edges(get_irg_end(irg), free);
422 /* handle anchored nodes */
423 for (i = anchor_last - 1; i >= 0; --i) {
424 n = get_irg_anchor(irg, i);
425 if (!irn_visited_else_mark(n)) {
426 size_t n_outs = PTR_TO_INT(n->out);
430 #endif /* defined DEBUG_libfirm */
438 /* compute the outs for a given graph */
439 void compute_irg_outs(ir_graph *irg)
441 ir_graph *rem = current_ir_graph;
443 ir_def_use_edge *end = NULL; /* Only for debugging */
445 current_ir_graph = irg;
447 /* Update graph state */
448 assert(get_irg_phase_state(current_ir_graph) != phase_building);
450 if (current_ir_graph->outs_state != outs_none)
451 free_irg_outs(current_ir_graph);
453 /* This first iteration counts the overall number of out edges and the
454 number of out edges for each node. */
455 n_out_edges = count_outs(irg);
457 /* allocate memory for all out edges. */
458 irg->outs = XMALLOCNZ(ir_def_use_edge, n_out_edges);
460 irg->n_outs = n_out_edges;
461 #endif /* defined DEBUG_libfirm */
463 /* The second iteration splits the irg->outs array into smaller arrays
464 for each node and writes the back edges into this array. */
465 end = set_out_edges(irg, irg->outs);
467 /* Check how much memory we have used */
468 assert (end == (irg->outs + n_out_edges));
470 current_ir_graph->outs_state = outs_consistent;
471 current_ir_graph = rem;
474 void assure_irg_outs(ir_graph *irg)
476 if (get_irg_outs_state(irg) != outs_consistent)
477 compute_irg_outs(irg);
480 void compute_irp_outs(void)
483 for (i = 0, n = get_irp_n_irgs(); i < n; ++i)
484 compute_irg_outs(get_irp_irg(i));
487 void free_irp_outs(void)
490 for (i = 0, n = get_irp_n_irgs(); i < n; ++i)
491 free_irg_outs(get_irp_irg(i));
494 void free_irg_outs(ir_graph *irg)
496 /* current_ir_graph->outs_state = outs_none; */
497 irg->outs_state = outs_none;
501 memset(irg->outs, 0, irg->n_outs);
502 #endif /* defined DEBUG_libfirm */
507 #endif /* defined DEBUG_libfirm */
511 /* when debugging, *always* reset all nodes' outs! irg->outs might
512 have been lying to us */
513 irg_walk_graph (irg, reset_outs, NULL, NULL);
514 #endif /* defined DEBUG_libfirm */