3 * File name: ir/ana/irouts.c
4 * Purpose: Compute and access out edges.
5 * Author: Goetz Lindenmaier
9 * Copyright: (c) 2002-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
14 * @file irouts.c Compute out edges for ir nodes (also called def-use edges).
16 * Copyright (C) 2002 by Universitaet Karlsruhe
17 * All rights reserved.
19 * Authors: Goetz Lindenmaier
33 #include "irgraph_t.h"
39 /* Note: ir_node.out_valid and ir_graph.n_outs are only present when DEBUG_libfirm is defined */
40 /* Accesses to out_valid and n_outs are fenced out to avoid breakage
41 when compiling with neither DEBUG_libfirm or NDEBUG defined */
42 #endif /* defined DEBUG_libfirm */
44 /*--------------------------------------------------------------------*/
45 /** Accessing the out datastructures **/
46 /*--------------------------------------------------------------------*/
48 /** Clear the outs of a node */
49 static void reset_outs (ir_node *node, void *unused)
54 #endif /* defined DEBUG_libfirm */
57 /* returns the number of successors of the node: */
58 int get_irn_n_outs (ir_node *node) {
59 assert(node && node->kind == k_ir_node);
61 /* assert (node->out_valid); */
62 #endif /* defined DEBUG_libfirm */
63 return PTR_TO_INT(node->out[0]);
66 /* Access successor n */
67 ir_node *get_irn_out (ir_node *node, int pos) {
68 assert(pos >= 0 && pos < get_irn_n_outs(node));
70 /* assert (node->out_valid); */
71 #endif /* defined DEBUG_libfirm */
72 return node->out[pos+1];
75 void set_irn_out (ir_node *node, int pos, ir_node *out) {
77 assert(pos >= 0 && pos < get_irn_n_outs(node));
79 node->out_valid = 1; /* assume that this function is used correctly */
80 #endif /* defined DEBUG_libfirm */
81 node->out[pos+1] = out;
85 int get_Block_n_cfg_outs(ir_node *bl) {
86 int i, n_cfg_outs = 0;
87 assert(bl && is_Block(bl));
89 assert (bl->out_valid);
90 #endif /* defined DEBUG_libfirm */
91 for (i = 1; i <= PTR_TO_INT(bl->out[0]); i++)
92 if ((get_irn_mode(bl->out[i]) == mode_X) &&
93 (get_irn_op(bl->out[i]) != op_End))
99 ir_node *get_Block_cfg_out(ir_node *bl, int pos) {
101 assert(bl && (get_irn_op(bl) == op_Block));
103 assert (bl->out_valid);
104 #endif /* defined DEBUG_libfirm */
105 for (i = 1; i <= PTR_TO_INT(bl->out[0]); i++)
106 if ((get_irn_mode(bl->out[i]) == mode_X) &&
107 (get_irn_op(bl->out[i]) != op_End)) {
108 if (out_pos == pos) {
109 ir_node *cfop = bl->out[i];
117 static void irg_out_walk_2(ir_node *node, irg_walk_func *pre,
118 irg_walk_func *post, void *env) {
123 assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
125 set_irn_visited(node, get_irg_visited(current_ir_graph));
127 if (pre) pre(node, env);
129 for (i = 0; i < get_irn_n_outs(node); i++) {
130 succ = get_irn_out(node, i);
131 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
132 irg_out_walk_2(succ, pre, post, env);
135 if (post) post(node, env);
140 void irg_out_walk(ir_node *node,
141 irg_walk_func *pre, irg_walk_func *post,
144 if (get_irg_outs_state(current_ir_graph) != outs_none) {
145 inc_irg_visited (current_ir_graph);
146 irg_out_walk_2(node, pre, post, env);
151 static void irg_out_block_walk2(ir_node *bl,
152 irg_walk_func *pre, irg_walk_func *post,
156 if(get_Block_block_visited(bl) < get_irg_block_visited(current_ir_graph)) {
157 set_Block_block_visited(bl, get_irg_block_visited(current_ir_graph));
162 for(i = 0; i < get_Block_n_cfg_outs(bl); i++) {
163 /* find the corresponding predecessor block. */
164 ir_node *pred = get_Block_cfg_out(bl, i);
166 irg_out_block_walk2(pred, pre, post, env);
175 /* Walks only over Block nodes in the graph. Has it's own visited
176 flag, so that it can be interleaved with the other walker. */
177 void irg_out_block_walk(ir_node *node,
178 irg_walk_func *pre, irg_walk_func *post,
181 assert((get_irn_op(node) == op_Block) || (get_irn_mode(node) == mode_X));
183 inc_irg_block_visited(current_ir_graph);
185 if (get_irn_mode(node) == mode_X) node = node->out[1];
187 irg_out_block_walk2(node, pre, post, env);
193 /*--------------------------------------------------------------------*/
194 /** Building and Removing the out datasturcture **/
196 /** The outs of a graph are allocated in a single, large array. **/
197 /** This allows to allocate and deallocate the memory for the outs **/
198 /** on demand. The large array is separated into many small ones **/
199 /** for each node. Only a single field to reference the out array **/
200 /** is stored in each node and a field referencing the large out **/
201 /** array in irgraph. The 0 field of each out array contains the **/
202 /** size of this array. This saves memory in the irnodes themselves.**/
203 /** The construction does two passes over the graph. The first pass **/
204 /** counts the overall number of outs and the outs of each node. It **/
205 /** stores the outs of each node in the out reference of the node. **/
206 /** Then the large array is allocated. The second iteration chops **/
207 /** the large array into smaller parts, sets the out edges and **/
208 /** recounts the out edges. **/
209 /** Removes Tuple nodes! **/
210 /*--------------------------------------------------------------------*/
213 /** Returns the amount of out edges for not yet visited successors. */
214 static int _count_outs(ir_node *n) {
215 int start, i, res, irn_arity;
218 n->out = (ir_node **) 1; /* Space for array size. */
220 start = is_Block(n) ? 0 : -1;
221 irn_arity = get_irn_arity(n);
222 res = irn_arity - start + 1; /* --1 or --0; 1 for array size. */
224 for (i = start; i < irn_arity; ++i) {
225 /* Optimize Tuples. They annoy if walking the cfg. */
226 ir_node *pred = skip_Tuple(get_irn_n(n, i));
227 set_irn_n(n, i, pred);
229 /* count outs for successors */
230 if (irn_not_visited(pred))
231 res += _count_outs(pred);
234 pred->out = (ir_node **)INT_TO_PTR(PTR_TO_INT(pred->out) + 1);
240 /** Returns the amount of out edges for not yet visited successors.
241 * This version handles some special nodes like irg_frame etc.
243 static int count_outs(ir_graph *irg) {
247 inc_irg_visited(irg);
248 res = _count_outs(get_irg_end(irg));
250 /* now handle special nodes */
251 n = get_irg_frame(irg);
252 if (irn_not_visited(n)) {
253 n->out = (ir_node **)1;
261 * Enter memory for the outs to a node.
263 * @param n current node
264 * @param free current free address in the chunk allocated for the outs
266 * @return The next free address
268 static ir_node **_set_out_edges(ir_node *n, ir_node **free) {
269 int n_outs, start, i, irn_arity;
272 set_irn_visited(n, get_irg_visited(current_ir_graph));
274 /* Allocate my array */
275 n_outs = PTR_TO_INT(n->out);
279 #endif /* defined DEBUG_libfirm */
281 /* We count the successors again, the space will be sufficient.
282 We use this counter to remember the position for the next back
284 n->out[0] = (ir_node *)0;
286 start = is_Block(n) ? 0 : -1;
287 irn_arity = get_irn_arity(n);
289 for (i = start; i < irn_arity; i++) {
290 pred = get_irn_n(n, i);
292 if (get_irn_visited(pred) < get_irg_visited(current_ir_graph))
293 free = _set_out_edges(pred, free);
294 /* Remember our back edge */
295 pred->out[get_irn_n_outs(pred)+1] = n;
296 pred->out[0] = INT_TO_PTR(get_irn_n_outs(pred) + 1);
302 * Enter memory for the outs to a node. Handles special nodes
304 * @param irg the graph
305 * @param free current free address in the chunk allocated for the outs
307 * @return The next free address
309 static ir_node **set_out_edges(ir_graph *irg, ir_node **free) {
313 inc_irg_visited(irg);
314 free = _set_out_edges(get_irg_end(irg), free);
316 n = get_irg_frame(irg);
317 if (get_irn_visited(n) < get_irg_visited(current_ir_graph)) {
318 n_outs = PTR_TO_INT(n->out);
322 #endif /* defined DEBUG_libfirm */
330 /* We want that the out of ProjX from Start contains the next block at
331 position 1, the Start block at position 2. This is necessary for
332 the out block walker. */
333 static INLINE void fix_start_proj(ir_graph *irg) {
334 ir_node *proj = NULL;
335 ir_node *startbl = get_irg_start_block(irg);
338 if (get_Block_n_cfg_outs(startbl)) {
339 for (i = 0; i < get_irn_n_outs(startbl); i++)
340 if (get_irn_mode(get_irn_out(startbl, i)) == mode_X) {
341 proj = get_irn_out(startbl, i);
345 if (get_irn_out(proj, 0) == startbl) {
346 assert(get_irn_n_outs(proj) == 2);
347 set_irn_out(proj, 0, get_irn_out(proj, 1));
348 set_irn_out(proj, 1, startbl);
353 /* compute the outs for a given graph */
354 void compute_irg_outs(ir_graph *irg) {
355 ir_graph *rem = current_ir_graph;
357 ir_node **end = NULL; /* Only for debugging */
359 current_ir_graph = irg;
361 /* Update graph state */
362 assert(get_irg_phase_state(current_ir_graph) != phase_building);
364 if (current_ir_graph->outs_state != outs_none)
365 free_irg_outs(current_ir_graph);
366 current_ir_graph->outs_state = outs_consistent;
368 /* This first iteration counts the overall number of out edges and the
369 number of out edges for each node. */
370 n_out_edges = count_outs(irg);
372 /* allocate memory for all out edges. */
373 irg->outs = xcalloc(n_out_edges, sizeof(irg->outs[0]));
375 irg->n_outs = n_out_edges;
376 #endif /* defined DEBUG_libfirm */
378 /* The second iteration splits the irg->outs array into smaller arrays
379 for each node and writes the back edges into this array. */
380 end = set_out_edges(irg, irg->outs);
382 /* Check how much memory we have used */
383 assert (end == (irg->outs + n_out_edges));
385 /* We want that the out of ProjX from Start contains the next block at
386 position 1, the Start block at position 2. This is necessary for
387 the out block walker. */
390 current_ir_graph = rem;
393 void compute_irp_outs(void) {
394 int i, n_irgs = get_irp_n_irgs();
395 for (i = 0; i < n_irgs; ++i)
396 compute_irg_outs(get_irp_irg(i));
398 void free_irp_outs(void) {
399 int i, n_irgs = get_irp_n_irgs();
400 for (i = 0; i < n_irgs; ++i)
401 free_irg_outs(get_irp_irg(i));
405 /*------------------------------------------------------------*
406 * This computes the outedges for in interprocedural graph. *
407 * There is one quirk: *
408 * The number of the outedges for each node is saved in *
409 * the first member of the ir_node** array. Maybe we should *
410 * change this to make it more portable... *
411 *------------------------------------------------------------*/
415 * Inits the number of outedges for each node
418 static void init_count(ir_node * node, void *env) {
419 node->out = (ir_node **) 1; /* 1 for the array size */
424 * Adjusts the out edge count for its predecessors
425 * and adds the current arity to the overall count,
426 * which is saved in "env"
428 static void node_arity_count(ir_node * node, void * env)
430 int *anz = (int *) env, arity, n_outs, i, start;
433 arity = get_irn_arity(node);
434 start = (is_Block(node)) ? 0 : -1;
436 n_outs = 1 + arity + (-start); // ((is_Block(node)) ? 0 : 1); // Why + 1??
439 for(i = start; i < arity; i++) {
440 succ = get_irn_n(node, i);
441 succ->out = (ir_node **)INT_TO_PTR(PTR_TO_INT(succ->out) + 1);
447 * Inits all nodes for setting the outedges
448 * Returns the overall count of edges
450 int count_ip_outs(void) {
454 cg_walk(init_count, node_arity_count, &res);
459 static int dummy_count = 0, global_count; /* Only for debugging */
462 * For each node: Sets the pointer to array
463 * in which the outedges are written later.
464 * The current array start is transported in env
466 static void set_array_pointer(ir_node *node, void *env) {
469 ir_node ***free = (ir_node ***) env;
471 /* Allocate my array */
472 n_outs = PTR_TO_INT(node->out); /* We wrote the count here in count_ip_outs */
473 dummy_count += n_outs;
474 assert(dummy_count <= global_count && "More outedges than initially counted!");
476 *free = &((*free)[n_outs]);
477 /* We count the successors again, the space will be sufficient.
478 We use this counter to remember the position for the next back
480 node -> out[0] = (ir_node *) 0;
485 * Adds an outedge from the predecessor to the
488 static void set_out_pointer(ir_node * node, void * env) {
489 int i, arity = get_irn_arity(node);
491 int start = (!is_Block(node)) ? -1 : 0;
493 for (i = start; i < arity; i++) {
494 succ = get_irn_n(node, i);
495 succ->out[get_irn_n_outs(succ)+1] = node;
496 succ->out[0] = INT_TO_PTR(get_irn_n_outs(succ) + 1);
502 * Sets the outedges for all nodes.
504 void set_ip_outs(void)
506 ir_node **outedge_array = get_irp_ip_outedges();
507 cg_walk(set_array_pointer, set_out_pointer, (void *) &outedge_array);
513 * Counts the outedges, allocates memory to save the
514 * outedges and fills this outedge array in interprocedural
517 void compute_ip_outs(void) {
522 assert(get_irp_ip_view_state() == ip_view_valid &&
523 "Cannot construct outs for invalid ip view.");
525 if (irp->outs_state != outs_none) {
529 global_count = n_out_edges = count_ip_outs();
530 out_edges = xcalloc(n_out_edges, sizeof(out_edges[0]));
531 set_irp_ip_outedges(out_edges);
535 void free_ip_outs(void)
537 ir_node **out_edges = get_irp_ip_outedges();
538 if (out_edges != NULL) {
540 set_irp_ip_outedges(NULL);
542 irp->outs_state = outs_none;
546 void free_irg_outs(ir_graph *irg) {
548 /* current_ir_graph->outs_state = outs_none; */
549 irg->outs_state = outs_none;
553 memset(irg->outs, 0, irg->n_outs);
554 #endif /* defined DEBUG_libfirm */
559 #endif /* defined DEBUG_libfirm */
563 /* when debugging, *always* reset all nodes' outs! irg->outs might
564 have been lying to us */
565 irg_walk_graph (irg, reset_outs, NULL, NULL);
566 #endif /* defined DEBUG_libfirm */