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 and access out edges (also called def-use edges).
23 * @author Goetz Lindenmaier, Michael Beck
36 #include "irgraph_t.h"
44 /* Note: ir_node.out_valid and ir_graph.n_outs are only present when DEBUG_libfirm is defined */
45 /* Accesses to out_valid and n_outs are fenced out to avoid breakage
46 when compiling with neither DEBUG_libfirm or NDEBUG defined */
47 #endif /* defined DEBUG_libfirm */
49 /*--------------------------------------------------------------------*/
50 /** Accessing the out datastructures **/
51 /*--------------------------------------------------------------------*/
54 /** Clear the outs of a node */
55 static void reset_outs(ir_node *node, void *unused) {
62 int get_irn_outs_computed(const ir_node *node)
64 return node->out != NULL;
67 /* returns the number of successors of the node: */
68 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) {
79 assert(pos >= 0 && pos < get_irn_n_outs(def));
81 /* assert(def->out_valid); */
82 #endif /* defined DEBUG_libfirm */
83 return def->out[pos+1].use;
86 /* Access successor n */
87 ir_node *get_irn_out_ex(const ir_node *def, int pos, int *in_pos) {
88 assert(pos >= 0 && pos < get_irn_n_outs(def));
90 /* assert(def->out_valid); */
91 #endif /* defined DEBUG_libfirm */
92 *in_pos = def->out[pos+1].pos;
93 return def->out[pos+1].use;
96 void set_irn_out(ir_node *def, int pos, ir_node *use, int in_pos) {
98 assert(pos >= 0 && pos < get_irn_n_outs(def));
100 def->out_valid = 1; /* assume that this function is used correctly */
101 #endif /* defined DEBUG_libfirm */
102 def->out[pos+1].use = use;
103 def->out[pos+1].pos = in_pos;
106 /* Return the number of control flow successors, ignore keep-alives. */
107 int get_Block_n_cfg_outs(const ir_node *bl) {
108 int i, n_cfg_outs = 0;
109 assert(bl && is_Block(bl));
111 assert(bl->out_valid);
112 #endif /* defined DEBUG_libfirm */
113 for (i = 1; i <= bl->out[0].pos; ++i) {
114 ir_node *succ = bl->out[i].use;
115 if (get_irn_mode(succ) == mode_X && !is_End(succ))
116 n_cfg_outs += succ->out[0].pos;
121 /* Return the number of control flow successors, honor keep-alives. */
122 int get_Block_n_cfg_outs_ka(const ir_node *bl) {
123 int i, n_cfg_outs = 0;
124 assert(bl && is_Block(bl));
126 assert(bl->out_valid);
127 #endif /* defined DEBUG_libfirm */
128 for (i = 1; i <= bl->out[0].pos; ++i) {
129 ir_node *succ = bl->out[i].use;
130 if (get_irn_mode(succ) == mode_X) {
133 /* ignore End if we are in the Endblock */
134 if (get_nodes_block(succ) == bl)
136 else /* count Keep-alive as one */
139 n_cfg_outs += succ->out[0].pos;
145 /* Access predecessor n, ignore keep-alives. */
146 ir_node *get_Block_cfg_out(const ir_node *bl, int pos) {
148 assert(bl && is_Block(bl));
150 assert(bl->out_valid);
151 #endif /* defined DEBUG_libfirm */
152 for (i = 1; i <= bl->out[0].pos; ++i) {
153 ir_node *succ = bl->out[i].use;
154 if (get_irn_mode(succ) == mode_X && !is_End(succ)) {
155 int n_outs = succ->out[0].pos;
157 return succ->out[pos + 1].use;
165 /* Access predecessor n, honor keep-alives. */
166 ir_node *get_Block_cfg_out_ka(const ir_node *bl, int pos) {
168 assert(bl && is_Block(bl));
170 assert (bl->out_valid);
171 #endif /* defined DEBUG_libfirm */
172 for (i = 1; i <= bl->out[0].pos; ++i) {
173 ir_node *succ = bl->out[i].use;
174 if (get_irn_mode(succ) == mode_X) {
176 ir_node *end_bl = get_nodes_block(succ);
178 /* ignore End if we are in the Endblock */
182 /* handle keep-alive here: return the Endblock instead of the End node */
187 n_outs = succ->out[0].pos;
189 return succ->out[pos + 1].use;
198 static void irg_out_walk_2(ir_node *node, irg_walk_func *pre,
199 irg_walk_func *post, void *env) {
204 assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
206 set_irn_visited(node, get_irg_visited(current_ir_graph));
208 if (pre) pre(node, env);
210 for (i = 0, n = get_irn_n_outs(node); i < n; ++i) {
211 succ = get_irn_out(node, i);
212 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
213 irg_out_walk_2(succ, pre, post, env);
216 if (post) post(node, env);
219 void irg_out_walk(ir_node *node,
220 irg_walk_func *pre, irg_walk_func *post,
223 if (get_irg_outs_state(current_ir_graph) != outs_none) {
224 inc_irg_visited (current_ir_graph);
225 irg_out_walk_2(node, pre, post, env);
229 static void irg_out_block_walk2(ir_node *bl,
230 irg_walk_func *pre, irg_walk_func *post,
234 if (!Block_block_visited(bl)) {
235 mark_Block_block_visited(bl);
240 for (i = 0, n = get_Block_n_cfg_outs(bl); i < n; ++i) {
241 /* find the corresponding predecessor block. */
242 ir_node *pred = get_Block_cfg_out(bl, i);
244 irg_out_block_walk2(pred, pre, post, env);
252 /* Walks only over Block nodes in the graph. Has it's own visited
253 flag, so that it can be interleaved with the other walker. */
254 void irg_out_block_walk(ir_node *node,
255 irg_walk_func *pre, irg_walk_func *post,
258 assert(is_Block(node) || (get_irn_mode(node) == mode_X));
260 inc_irg_block_visited(current_ir_graph);
262 if (get_irn_mode(node) == mode_X) {
265 for (i = 0, n = get_irn_n_outs(node); i < n; ++i) {
266 ir_node *succ = get_irn_out(node, i);
267 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
268 irg_out_walk_2(succ, pre, post, env);
272 irg_out_block_walk2(node, pre, post, env);
276 /*--------------------------------------------------------------------*/
277 /** Building and Removing the out datastructure **/
279 /** The outs of a graph are allocated in a single, large array. **/
280 /** This allows to allocate and deallocate the memory for the outs **/
281 /** on demand. The large array is separated into many small ones **/
282 /** for each node. Only a single field to reference the out array **/
283 /** is stored in each node and a field referencing the large out **/
284 /** array in irgraph. The 0 field of each out array contains the **/
285 /** size of this array. This saves memory in the irnodes themselves.**/
286 /** The construction does two passes over the graph. The first pass **/
287 /** counts the overall number of outs and the outs of each node. It **/
288 /** stores the outs of each node in the out reference of the node. **/
289 /** Then the large array is allocated. The second iteration chops **/
290 /** the large array into smaller parts, sets the out edges and **/
291 /** recounts the out edges. **/
292 /** Removes Tuple nodes! **/
293 /*--------------------------------------------------------------------*/
296 /** Returns the amount of out edges for not yet visited successors. */
297 static int _count_outs(ir_node *n) {
298 int start, i, res, irn_arity;
301 n->out = INT_TO_PTR(1); /* Space for array size. */
303 start = is_Block(n) ? 0 : -1;
304 irn_arity = get_irn_arity(n);
305 res = irn_arity - start + 1; /* --1 or --0; 1 for array size. */
307 for (i = start; i < irn_arity; ++i) {
308 /* Optimize Tuples. They annoy if walking the cfg. */
309 ir_node *pred = get_irn_n(n, i);
310 ir_node *skipped_pred = skip_Tuple(pred);
312 if (skipped_pred != pred) {
313 set_irn_n(n, i, skipped_pred);
316 /* count Def-Use edges for predecessors */
317 if (!irn_visited(skipped_pred))
318 res += _count_outs(skipped_pred);
320 /*count my Def-Use edges */
321 skipped_pred->out = INT_TO_PTR(PTR_TO_INT(skipped_pred->out) + 1);
327 /** Returns the amount of out edges for not yet visited successors.
328 * This version handles some special nodes like irg_frame, irg_args etc.
330 static int count_outs(ir_graph *irg) {
334 inc_irg_visited(irg);
335 res = _count_outs(get_irg_end(irg));
337 /* Now handle anchored nodes. We need the out count of those
338 even if they are not visible. */
339 for (i = anchor_last - 1; i >= 0; --i) {
340 n = get_irg_anchor(irg, i);
341 if (!irn_visited_else_mark(n)) {
342 n->out = INT_TO_PTR(1);
350 * Enter memory for the outs to a node.
352 * @param use current node
353 * @param free current free address in the chunk allocated for the outs
355 * @return The next free address
357 static ir_def_use_edge *_set_out_edges(ir_node *use, ir_def_use_edge *free) {
358 int n_outs, start, i, irn_arity, pos;
360 mark_irn_visited(use);
362 /* Allocate my array */
363 n_outs = PTR_TO_INT(use->out);
367 #endif /* defined DEBUG_libfirm */
369 /* We count the successors again, the space will be sufficient.
370 We use this counter to remember the position for the next back
374 start = is_Block(use) ? 0 : -1;
375 irn_arity = get_irn_arity(use);
377 for (i = start; i < irn_arity; ++i) {
378 ir_node *def = get_irn_n(use, i);
381 if (!irn_visited(def))
382 free = _set_out_edges(def, free);
384 /* Remember this Def-Use edge */
385 pos = def->out[0].pos + 1;
386 def->out[pos].use = use;
387 def->out[pos].pos = i;
389 /* increase the number of Def-Use edges so far */
390 def->out[0].pos = pos;
396 * Enter memory for the outs to a node. Handles special nodes
398 * @param irg the graph
399 * @param free current free address in the chunk allocated for the outs
401 * @return The next free address
403 static ir_def_use_edge *set_out_edges(ir_graph *irg, ir_def_use_edge *free) {
407 inc_irg_visited(irg);
408 free = _set_out_edges(get_irg_end(irg), free);
410 /* handle anchored nodes */
411 for (i = anchor_last - 1; i >= 0; --i) {
412 n = get_irg_anchor(irg, i);
413 if (!irn_visited_else_mark(n)) {
414 n_outs = PTR_TO_INT(n->out);
418 #endif /* defined DEBUG_libfirm */
428 * We want that the out of ProjX from Start contains the next block at
429 * position 0, the Start block at position 1. This is necessary for
430 * the out block walker.
432 static INLINE void fix_start_proj(ir_graph *irg) {
433 ir_node *startbl = get_irg_start_block(irg);
435 if (get_Block_n_cfg_outs(startbl)) {
436 ir_node *proj = get_irg_initial_exec(irg);
438 int block_pos, other_pos;
440 if (get_irn_n_outs(proj) == 2) {
441 if (get_irn_out_ex(proj, 0, &block_pos) == startbl) {
442 irn = get_irn_out_ex(proj, 1, &other_pos);
443 set_irn_out(proj, 0, irn, other_pos);
444 set_irn_out(proj, 1, startbl, block_pos);
447 assert(get_irg_phase_state(irg) == phase_backend);
452 /* compute the outs for a given graph */
453 void compute_irg_outs(ir_graph *irg) {
454 ir_graph *rem = current_ir_graph;
456 ir_def_use_edge *end = NULL; /* Only for debugging */
458 current_ir_graph = irg;
460 /* Update graph state */
461 assert(get_irg_phase_state(current_ir_graph) != phase_building);
463 if (current_ir_graph->outs_state != outs_none)
464 free_irg_outs(current_ir_graph);
466 /* This first iteration counts the overall number of out edges and the
467 number of out edges for each node. */
468 n_out_edges = count_outs(irg);
470 /* allocate memory for all out edges. */
471 irg->outs = XMALLOCNZ(ir_def_use_edge, n_out_edges);
473 irg->n_outs = n_out_edges;
474 #endif /* defined DEBUG_libfirm */
476 /* The second iteration splits the irg->outs array into smaller arrays
477 for each node and writes the back edges into this array. */
478 end = set_out_edges(irg, irg->outs);
480 /* Check how much memory we have used */
481 assert (end == (irg->outs + n_out_edges));
483 /* We want that the out of ProjX from Start contains the next block at
484 position 0, the Start block at position 1. This is necessary for
485 code placement (place_early() ONLY if started GCSE on graphs with dead blocks) */
488 current_ir_graph->outs_state = outs_consistent;
489 current_ir_graph = rem;
492 void assure_irg_outs(ir_graph *irg) {
493 if (get_irg_outs_state(irg) != outs_consistent)
494 compute_irg_outs(irg);
497 void compute_irp_outs(void) {
499 for (i = get_irp_n_irgs() -1; i >= 0; --i)
500 compute_irg_outs(get_irp_irg(i));
503 void free_irp_outs(void) {
505 for (i = get_irp_n_irgs() -1; i >= 0; --i)
506 free_irg_outs(get_irp_irg(i));
510 /*------------------------------------------------------------*
511 * This computes the outedges for in interprocedural graph. *
512 * There is one quirk: *
513 * The number of the outedges for each node is saved in *
514 * the first member of the ir_node** array. Maybe we should *
515 * change this to make it more portable... *
516 *------------------------------------------------------------*/
519 #ifdef INTERPROCEDURAL_VIEW
521 * Inits the number of outedges for each node
524 static void init_count(ir_node * node, void *env) {
526 node->out = (ir_node **) 1; /* 1 for the array size */
531 * Adjusts the out edge count for its predecessors
532 * and adds the current arity to the overall count,
533 * which is saved in "env"
535 static void node_arity_count(ir_node * node, void * env) {
536 int *anz = (int *) env, arity, n_outs, i, start;
539 arity = get_irn_arity(node);
540 start = (is_Block(node)) ? 0 : -1;
542 n_outs = 1 + arity + (-start); // ((is_Block(node)) ? 0 : 1); // Why + 1??
545 for(i = start; i < arity; i++) {
546 succ = get_irn_n(node, i);
547 succ->out = (ir_node **)INT_TO_PTR(PTR_TO_INT(succ->out) + 1);
552 * Inits all nodes for setting the outedges
553 * Returns the overall count of edges
555 int count_ip_outs(void) {
558 cg_walk(init_count, node_arity_count, &res);
563 static int dummy_count = 0, global_count; /* Only for debugging */
566 * For each node: Sets the pointer to array
567 * in which the outedges are written later.
568 * The current array start is transported in env
570 static void set_array_pointer(ir_node *node, void *env) {
572 ir_node ***free = (ir_node ***) env;
574 /* Allocate my array */
575 n_outs = PTR_TO_INT(node->out); /* We wrote the count here in count_ip_outs */
576 dummy_count += n_outs;
577 assert(dummy_count <= global_count && "More outedges than initially counted!");
579 *free = &((*free)[n_outs]);
580 /* We count the successors again, the space will be sufficient.
581 We use this counter to remember the position for the next back
583 node -> out[0] = (ir_node *) 0;
588 * Adds an outedge from the predecessor to the
591 static void set_out_pointer(ir_node * node, void *env) {
592 int i, arity = get_irn_arity(node);
594 int start = (!is_Block(node)) ? -1 : 0;
597 for (i = start; i < arity; ++i) {
598 succ = get_irn_n(node, i);
599 succ->out[get_irn_n_outs(succ)+1] = node;
600 succ->out[0] = INT_TO_PTR(get_irn_n_outs(succ) + 1);
606 * Sets the outedges for all nodes.
608 void set_ip_outs(void) {
609 ir_node **outedge_array = get_irp_ip_outedges();
610 cg_walk(set_array_pointer, set_out_pointer, (void *) &outedge_array);
616 * Counts the outedges, allocates memory to save the
617 * outedges and fills this outedge array in interprocedural
620 void compute_ip_outs(void) {
624 assert(get_irp_ip_view_state() == ip_view_valid &&
625 "Cannot construct outs for invalid ip view.");
627 if (irp->outs_state != outs_none) {
631 global_count = n_out_edges = count_ip_outs();
632 out_edges = XMALLOCNZ(ir_node*, n_out_edges);
633 set_irp_ip_outedges(out_edges);
637 void free_ip_outs(void) {
638 ir_node **out_edges = get_irp_ip_outedges();
639 if (out_edges != NULL) {
641 set_irp_ip_outedges(NULL);
643 irp->outs_state = outs_none;
648 void free_irg_outs(ir_graph *irg) {
649 /* current_ir_graph->outs_state = outs_none; */
650 irg->outs_state = outs_none;
654 memset(irg->outs, 0, irg->n_outs);
655 #endif /* defined DEBUG_libfirm */
660 #endif /* defined DEBUG_libfirm */
664 /* when debugging, *always* reset all nodes' outs! irg->outs might
665 have been lying to us */
666 irg_walk_graph (irg, reset_outs, NULL, NULL);
667 #endif /* defined DEBUG_libfirm */
670 static void check_out_edges(ir_node *irn, void *env) {
674 int last = is_Block(irn) ? 0 : -1;
676 /* check forward: every input must have an out edge */
677 for (i = get_irn_arity(irn) - 1; i >= last; --i) {
678 ir_node *pred = get_irn_n(irn, i);
680 for (j = get_irn_n_outs(pred) - 1; j >= 0; --j) {
681 ir_node *user = get_irn_out_ex(pred, j, &pos);
683 if (user == irn && pos == i) {
688 ir_fprintf(stderr, "Missing out edge from %+F input %d to %+F", irn, i, pred);
693 /* checking backward */
694 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
695 ir_node *user = get_irn_out_ex(irn, i, &pos);
697 if (get_irn_n(user, pos) != irn) {
698 ir_fprintf(stderr, "Spurious out edge from %+F output %d to %+F", irn, i, user);
705 /* verify outs edges. */
706 void verify_outs(ir_graph *irg) {
708 irg_walk_graph(irg, NULL, check_out_edges, &errors);
710 panic("Out edges are corrupt");