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"
38 /* Note: ir_node.out_valid and ir_graph.n_outs are only present when DEBUG_libfirm is defined */
39 /* Accesses to out_valid and n_outs are fenced out to avoid breakage
40 when compiling with neither DEBUG_libfirm or NDEBUG defined */
41 #endif /* defined DEBUG_libfirm */
43 /*--------------------------------------------------------------------*/
44 /** Accessing the out datastructures **/
45 /*--------------------------------------------------------------------*/
47 /** Clear the outs of a node */
48 static void reset_outs (ir_node *node, void *unused)
53 #endif /* defined DEBUG_libfirm */
56 /* returns the number of successors of the node: */
57 INLINE int get_irn_n_outs (ir_node *node) {
58 assert(node && node->kind == k_ir_node);
60 /* assert (node->out_valid); */
61 #endif /* defined DEBUG_libfirm */
62 return (int)(node->out[0]);
65 /* Access successor n */
66 INLINE ir_node *get_irn_out (ir_node *node, int pos) {
67 assert(pos >= 0 && pos < get_irn_n_outs(node));
69 /* assert (node->out_valid); */
70 #endif /* defined DEBUG_libfirm */
71 return node->out[pos+1];
74 INLINE void set_irn_out (ir_node *node, int pos, ir_node *out) {
76 assert(pos >= 0 && pos < get_irn_n_outs(node));
78 node->out_valid = 1; /* assume that this function is used correctly */
79 #endif /* defined DEBUG_libfirm */
80 node->out[pos+1] = out;
84 INLINE int get_Block_n_cfg_outs (ir_node *bl) {
85 int i, n_cfg_outs = 0;
86 assert(bl && (get_irn_op(bl) == op_Block));
88 assert (bl->out_valid);
89 #endif /* defined DEBUG_libfirm */
90 for (i = 0; i < (int)bl->out[0]; i++)
91 if ((get_irn_mode(bl->out[i+1]) == mode_X) &&
92 (get_irn_op(bl->out[i+1]) != op_End))
98 INLINE ir_node *get_Block_cfg_out (ir_node *bl, int pos) {
100 assert(bl && (get_irn_op(bl) == op_Block));
102 assert (bl->out_valid);
103 #endif /* defined DEBUG_libfirm */
104 for (i = 0; i < (int)bl->out[0]; i++)
105 if ((get_irn_mode(bl->out[i+1]) == mode_X) &&
106 (get_irn_op(bl->out[i+1]) != op_End)) {
107 if (out_pos == pos) {
108 ir_node *cfop = bl->out[i+1];
109 return cfop->out[0+1];
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;
217 set_irn_visited(n, get_irg_visited(current_ir_graph));
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 *succ = skip_Tuple(get_irn_n(n, i));
227 set_irn_n(n, i, succ);
229 /* count outs for successors */
230 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph)) {
231 res += count_outs(succ);
234 succ->out = (ir_node **)( (int)succ->out + 1);
240 * Enter memory for the outs to a node.
242 * @param n current node
243 * @param free current free address in the chunk allocated for the outs
245 * @return The next free address
247 static ir_node **set_out_edges(ir_node *n, ir_node **free) {
248 int n_outs, start, i, irn_arity;
251 set_irn_visited(n, get_irg_visited(current_ir_graph));
253 /* Allocate my array */
254 n_outs = (int) n->out;
258 #endif /* defined DEBUG_libfirm */
260 /* We count the successors again, the space will be sufficient.
261 We use this counter to remember the position for the next back
263 n->out[0] = (ir_node *)0;
265 start = is_Block(n) ? 0 : -1;
266 irn_arity = get_irn_arity(n);
268 for (i = start; i < irn_arity; i++) {
269 succ = get_irn_n(n, i);
271 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
272 free = set_out_edges(succ, free);
273 /* Remember our back edge */
274 succ->out[get_irn_n_outs(succ)+1] = n;
275 succ->out[0] = (ir_node *) (get_irn_n_outs(succ) + 1);
280 /* We want that the out of ProjX from Start contains the next block at
281 position 1, the Start block at position 2. This is necessary for
282 the out block walker. */
283 static INLINE void fix_start_proj(ir_graph *irg) {
284 ir_node *proj = NULL;
285 ir_node *startbl = get_irg_start_block(irg);
288 if (get_Block_n_cfg_outs(startbl)) {
289 for (i = 0; i < get_irn_n_outs(startbl); i++)
290 if (get_irn_mode(get_irn_out(startbl, i)) == mode_X) {
291 proj = get_irn_out(startbl, i);
295 if (get_irn_out(proj, 0) == startbl) {
296 assert(get_irn_n_outs(proj) == 2);
297 set_irn_out(proj, 0, get_irn_out(proj, 1));
298 set_irn_out(proj, 1, startbl);
303 /* compute the outs for a given graph */
304 void compute_outs(ir_graph *irg) {
305 ir_graph *rem = current_ir_graph;
307 ir_node **end = NULL; /* Only for debugging */
309 current_ir_graph = irg;
311 /* Update graph state */
312 assert(get_irg_phase_state(current_ir_graph) != phase_building);
314 if (current_ir_graph->outs_state != outs_none)
315 free_outs(current_ir_graph);
316 current_ir_graph->outs_state = outs_consistent;
318 /* This first iteration counts the overall number of out edges and the
319 number of out edges for each node. */
320 inc_irg_visited(irg);
321 n_out_edges = count_outs(get_irg_end(irg));
323 /* allocate memory for all out edges. */
324 irg->outs = (ir_node **) xmalloc (n_out_edges * sizeof(ir_node *));
326 irg->n_outs = n_out_edges;
327 #endif /* defined DEBUG_libfirm */
329 /* The second iteration splits the irg->outs array into smaller arrays
330 for each node and writes the back edges into this array. */
331 inc_irg_visited(irg);
332 end = set_out_edges(get_irg_end(irg), irg->outs);
334 /* Check how much memory we have used */
335 assert (end == (irg->outs + n_out_edges));
337 /* We want that the out of ProjX from Start contains the next block at
338 position 1, the Start block at position 2. This is necessary for
339 the out block walker. */
342 current_ir_graph = rem;
348 /*------------------------------------------------------------*
349 * This computes the outedges for in interprocedural graph. *
350 * There is one quirk: *
351 * The number of the outedges for each node is saved in *
352 * the first member of the ir_node** array. Maybe we should *
353 * change this to make it more portable... *
354 *------------------------------------------------------------*/
358 * Inits the number of outedges for each node
361 static void init_count(ir_node * node, void *env) {
362 node->out = (ir_node **) 1; /* 1 for the array size */
367 * Adjusts the out edge count for its predecessors
368 * and adds the current arity to the overall count,
369 * which is saved in "env"
371 static void node_arity_count(ir_node * node, void * env)
373 int *anz = (int *) env, arity, n_outs, i, start;
376 arity = get_irn_arity(node);
377 start = (is_Block(node)) ? 0 : -1;
379 n_outs = 1 + arity + (-start); // ((is_Block(node)) ? 0 : 1); // Why + 1??
382 for(i = start; i < arity; i++) {
383 succ = get_irn_n(node, i);
384 succ->out = (ir_node **)((int)succ->out + 1);
390 * Inits all nodes for setting the outedges
391 * Returns the overall count of edges
393 int count_ip_outs(void) {
397 cg_walk(init_count, node_arity_count, &res);
402 static int dummy_count = 0, global_count; /* Only for debugging */
405 * For each node: Sets the pointer to array
406 * in which the outedges are written later.
407 * The current array start is transported in env
409 static void set_array_pointer(ir_node *node, void *env) {
412 ir_node ***free = (ir_node ***) env;
414 /* Allocate my array */
415 n_outs = (int) node -> out; /* We wrote the count here in count_ip_outs */
416 dummy_count += n_outs;
417 assert(dummy_count <= global_count && "More outedges than initially counted!");
419 *free = &((*free)[n_outs]);
420 /* We count the successors again, the space will be sufficient.
421 We use this counter to remember the position for the next back
423 node -> out[0] = (ir_node *) 0;
428 * Adds an outedge from the predecessor to the
431 static void set_out_pointer(ir_node * node, void * env) {
432 int i, arity = get_irn_arity(node);
434 int start = (!is_Block(node)) ? -1 : 0;
436 for(i = start; i < arity; i++) {
437 succ = get_irn_n(node, i);
438 succ->out[get_irn_n_outs(succ)+1] = node;
439 succ->out[0] = (ir_node *) (get_irn_n_outs(succ) + 1);
445 * Sets the outedges for all nodes.
447 void set_ip_outs(void)
449 ir_node **outedge_array = get_irp_ip_outedges();
450 cg_walk(set_array_pointer, set_out_pointer, (void *) &outedge_array);
456 * Counts the outedges, allocates memory to save the
457 * outedges and fills this outedge array in interprocedural
460 void compute_ip_outs(void) {
465 assert(get_irp_ip_view_state() == ip_view_valid &&
466 "Cannot construct outs for invalid ip view.");
468 if (irp->outs_state != outs_none) {
472 global_count = n_out_edges = count_ip_outs();
473 out_edges = (ir_node **) xmalloc (n_out_edges * sizeof(ir_node *));
474 set_irp_ip_outedges(out_edges);
478 void free_ip_outs(void)
480 ir_node **out_edges = get_irp_ip_outedges();
481 if (out_edges != NULL) {
483 set_irp_ip_outedges(NULL);
485 irp->outs_state = outs_none;
489 void free_outs(ir_graph *irg) {
491 /* current_ir_graph->outs_state = outs_none; */
492 irg->outs_state = outs_none;
496 memset(irg->outs, 0, irg->n_outs);
497 #endif /* defined DEBUG_libfirm */
502 #endif /* defined DEBUG_libfirm */
506 /* when debugging, *always* reset all nodes' outs! irg->outs might
507 have been lying to us */
508 irg_walk_graph (irg, reset_outs, NULL, NULL);
509 #endif /* defined DEBUG_libfirm */