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.
15 /* Copyright (C) 2002 by Universitaet Karlsruhe
16 * All rights reserved.
18 * Authors: Goetz Lindenmaier
20 * irouts.c --- Compute out edges for ir nodes (also called def-use
28 #endif /* defined HAVE_CONFIG_H */
32 #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 static void reset_outs (ir_node *node, void *unused)
52 #endif /* defined DEBUG_libfirm */
55 /* returns the number of successors of the node: */
56 INLINE int get_irn_n_outs (ir_node *node) {
58 /* assert (node->out_valid); */
59 #endif /* defined DEBUG_libfirm */
60 return (int)(node->out[0]);
63 /* Access successor n */
64 INLINE ir_node *get_irn_out (ir_node *node, int pos) {
66 assert(pos >= 0 && pos < get_irn_n_outs(node));
68 /* assert (node->out_valid); */
69 #endif /* defined DEBUG_libfirm */
70 return node->out[pos+1];
73 INLINE void set_irn_out (ir_node *node, int pos, ir_node *out) {
75 assert(pos >= 0 && pos < get_irn_n_outs(node));
77 node->out_valid = 1; /* assume that this function is used correctly */
78 #endif /* defined DEBUG_libfirm */
79 node->out[pos+1] = out;
83 INLINE int get_Block_n_cfg_outs (ir_node *bl) {
84 int i, n_cfg_outs = 0;
85 assert(bl && (get_irn_op(bl) == op_Block));
87 assert (bl->out_valid);
88 #endif /* defined DEBUG_libfirm */
89 for (i = 0; i < (int)bl->out[0]; i++)
90 if ((get_irn_mode(bl->out[i+1]) == mode_X) &&
91 (get_irn_op(bl->out[i+1]) != op_End)) n_cfg_outs++;
96 INLINE ir_node *get_Block_cfg_out (ir_node *bl, int pos) {
98 assert(bl && (get_irn_op(bl) == op_Block));
100 assert (bl->out_valid);
101 #endif /* defined DEBUG_libfirm */
102 for (i = 0; i < (int)bl->out[0]; i++)
103 if ((get_irn_mode(bl->out[i+1]) == mode_X) &&
104 (get_irn_op(bl->out[i+1]) != op_End)) {
105 if (out_pos == pos) {
106 ir_node *cfop = bl->out[i+1];
107 return cfop->out[0+1];
115 void irg_out_walk_2(ir_node *node, irg_walk_func *pre,
116 irg_walk_func *post, void *env) {
121 assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
123 set_irn_visited(node, get_irg_visited(current_ir_graph));
125 if (pre) pre(node, env);
127 for (i = 0; i < get_irn_n_outs(node); i++) {
128 succ = get_irn_out(node, i);
129 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
130 irg_out_walk_2(succ, pre, post, env);
133 if (post) post(node, env);
138 void irg_out_walk(ir_node *node,
139 irg_walk_func *pre, irg_walk_func *post,
142 if (get_irg_outs_state(current_ir_graph) != outs_none) {
143 inc_irg_visited (current_ir_graph);
144 irg_out_walk_2(node, pre, post, env);
149 void irg_out_block_walk2(ir_node *bl,
150 irg_walk_func *pre, irg_walk_func *post,
154 if(get_Block_block_visited(bl) < get_irg_block_visited(current_ir_graph)) {
155 set_Block_block_visited(bl, get_irg_block_visited(current_ir_graph));
160 for(i = 0; i < get_Block_n_cfg_outs(bl); i++) {
161 /* find the corresponding predecessor block. */
162 ir_node *pred = get_Block_cfg_out(bl, i);
164 irg_out_block_walk2(pred, pre, post, env);
173 /* Walks only over Block nodes in the graph. Has it's own visited
174 flag, so that it can be interleaved with the other walker. */
175 void irg_out_block_walk(ir_node *node,
176 irg_walk_func *pre, irg_walk_func *post,
179 assert((get_irn_op(node) == op_Block) || (get_irn_mode(node) == mode_X));
181 inc_irg_block_visited(current_ir_graph);
183 if (get_irn_mode(node) == mode_X) node = node->out[1];
185 irg_out_block_walk2(node, pre, post, env);
191 /**********************************************************************/
192 /** Building and Removing the out datasturcture **/
194 /** The outs of a graph are allocated in a single, large array. **/
195 /** This allows to allocate and deallocate the memory for the outs **/
196 /** on demand. The large array is separated into many small ones **/
197 /** for each node. Only a single field to reference the out array **/
198 /** is stored in each node and a field referencing the large out **/
199 /** array in irgraph. The 0 field of each out array contains the **/
200 /** size of this array. This saves memory in the irnodes themselves.**/
201 /** The construction does two passes over the graph. The first pass **/
202 /** counts the overall number of outs and the outs of each node. It **/
203 /** stores the outs of each node in the out reference of the node. **/
204 /** Then the large array is allocated. The second iteration chops **/
205 /** the large array into smaller parts, sets the out edges and **/
206 /** recounts the out edges. **/
207 /** Removes Tuple nodes! **/
208 /**********************************************************************/
211 /* Returns the amount of out edges for not yet visited successors. */
212 static int count_outs(ir_node *n) {
213 int start, i, res, irn_arity;
216 set_irn_visited(n, get_irg_visited(current_ir_graph));
217 n->out = (ir_node **) 1; /* Space for array size. */
219 start = get_irn_op(n) == op_Block ? 0 : -1;
220 irn_arity = get_irn_arity(n);
221 res = irn_arity - start +1; /* --1 or --0; 1 for array size. */
222 for (i = start; i < irn_arity; i++) {
223 /* Optimize Tuples. They annoy if walking the cfg. */
224 succ = skip_Tuple(get_irn_n(n, i));
225 set_irn_n(n, i, succ);
226 /* count outs for successors */
227 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph)) {
228 res += count_outs(succ);
231 succ->out = (ir_node **)( (int)succ->out +1);
236 static ir_node **set_out_edges(ir_node *n, ir_node **free) {
237 int n_outs, start, i, irn_arity;
240 set_irn_visited(n, get_irg_visited(current_ir_graph));
242 /* Allocate my array */
243 n_outs = (int) n->out;
247 #endif /* defined DEBUG_libfirm */
248 free = &free[n_outs];
249 /* We count the successors again, the space will be sufficient.
250 We use this counter to remember the position for the next back
252 n->out[0] = (ir_node *)0;
254 if (get_irn_op(n) == op_Block) start = 0; else start = -1;
255 irn_arity = get_irn_arity(n);
256 for (i = start; i < irn_arity; i++) {
257 succ = get_irn_n(n, i);
259 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
260 free = set_out_edges(succ, free);
261 /* Remember our back edge */
262 succ->out[get_irn_n_outs(succ)+1] = n;
263 succ->out[0] = (ir_node *) (get_irn_n_outs(succ) + 1);
268 static INLINE void fix_start_proj(ir_graph *irg) {
269 ir_node *proj = NULL;
270 ir_node *startbl = get_irg_start_block(irg);
273 if (get_Block_n_cfg_outs(startbl)) {
274 for (i = 0; i < get_irn_n_outs(startbl); i++)
275 if (get_irn_mode(get_irn_out(startbl, i)) == mode_X) {
276 proj = get_irn_out(startbl, i);
280 if (get_irn_out(proj, 0) == startbl) {
281 assert(get_irn_n_outs(proj) == 2);
282 set_irn_out(proj, 0, get_irn_out(proj, 1));
283 set_irn_out(proj, 1, startbl);
288 void compute_outs(ir_graph *irg) {
289 ir_graph *rem = current_ir_graph;
291 ir_node **end = NULL; /* Only for debugging */
293 current_ir_graph = irg;
295 /* Update graph state */
296 assert(get_irg_phase_state(current_ir_graph) != phase_building);
297 if (current_ir_graph->outs_state != outs_none) free_outs(current_ir_graph);
298 current_ir_graph->outs_state = outs_consistent;
300 /* This first iteration counts the overall number of out edges and the
301 number of out edges for each node. */
302 inc_irg_visited(irg);
303 n_out_edges = count_outs(get_irg_end(irg));
305 /* allocate memory for all out edges. */
306 irg->outs = (ir_node **) xmalloc (n_out_edges * sizeof(ir_node *));
308 irg->n_outs = n_out_edges;
309 #endif /* defined DEBUG_libfirm */
311 /* The second iteration splits the irg->outs array into smaller arrays
312 for each node and writes the back edges into this array. */
313 inc_irg_visited(irg);
314 end = set_out_edges(get_irg_end(irg), irg->outs);
317 /* Check how much memory we have used */
318 assert (end == (irg->outs + n_out_edges));
319 #endif /* defined DEBUG_libfirm */
321 /* We want that the out of ProjX from Start contains the next block at
322 position 1, the Start block at position 2. This is necessary for
323 the out block walker. */
326 current_ir_graph = rem;
332 /*------------------------------------------------------------*
333 * This computes the outedges for in interprocedural graph. *
334 * There is one quirk: *
335 * The number of the outedges for each node is saved in *
336 * the first member of the ir_node** array. Maybe we should *
337 * change this to make it more portable... *
338 *------------------------------------------------------------*/
341 /* ------------------------------------------
342 Inits the number of outedges for each node
344 ------------------------------------------ */
346 static void init_count(ir_node * node, void * env)
348 node->out = (ir_node **) 1; /* 1 for the array size */
352 /* -----------------------------------------------
353 Adjusts the out edge count for its predecessors
354 and adds the current arity to the overall count,
355 which is saved in "env"
356 ------------------------------------------------ */
358 static void node_arity_count(ir_node * node, void * env)
360 int *anz = (int *) env, arity, n_outs, i, start;
363 arity = get_irn_arity(node);
364 start = (is_Block(node)) ? 0 : -1;
366 n_outs = 1 + arity + (-start); // ((is_Block(node)) ? 0 : 1); // Why + 1??
369 for(i = start; i < arity; i++) {
370 succ = get_irn_n(node, i);
371 succ->out = (ir_node **)((int)succ->out + 1);
376 /* ----------------------------------------
377 Inits all nodes for setting the outedges
378 Returns the overall count of edges
379 ---------------------------------------- */
381 int count_ip_outs(void) {
385 cg_walk(init_count, node_arity_count, &res);
390 int dummy_count = 0, global_count; /* Only for debugging */
392 /* ---------------------------------------------
393 For each node: Sets the pointer to array
394 in which the outedges are written later.
395 The current array start is transported in env
396 --------------------------------------------- */
398 static void set_array_pointer(ir_node *node, void *env) {
401 ir_node ***free = (ir_node ***) env;
403 /* Allocate my array */
404 n_outs = (int) node -> out; /* We wrote the count here in count_ip_outs */
405 dummy_count += n_outs;
406 assert(dummy_count <= global_count && "More outedges than initially counted!");
408 *free = &((*free)[n_outs]);
409 /* We count the successors again, the space will be sufficient.
410 We use this counter to remember the position for the next back
412 node -> out[0] = (ir_node *) 0;
416 /* -------------------------------------------
417 Adds an outedge from the predecessor to the
419 ------------------------------------------- */
421 static void set_out_pointer(ir_node * node, void * env) {
422 int i, arity = get_irn_arity(node);
424 int start = (!is_Block(node)) ? -1 : 0;
426 for(i = start; i < arity; i++) {
427 succ = get_irn_n(node, i);
428 succ->out[get_irn_n_outs(succ)+1] = node;
429 succ->out[0] = (ir_node *) (get_irn_n_outs(succ) + 1);
434 /* -------------------------------
435 Sets the outedges for all nodes.
436 -------------------------------- */
438 void set_ip_outs(void)
440 ir_node **outedge_array = get_irp_ip_outedges();
441 cg_walk(set_array_pointer, set_out_pointer, (void *) &outedge_array);
446 /* --------------------------------------------------------
447 Counts the outedges, allocates memory to save the
448 outedges and fills this outedge array in interprocedural
450 -------------------------------------------------------- */
452 void compute_ip_outs(void) {
457 assert(get_irp_ip_view_state() == ip_view_valid &&
458 "Cannot construct outs for invalid ip view.");
460 if (irp->outs_state != outs_none) {
464 global_count = n_out_edges = count_ip_outs();
465 out_edges = (ir_node **) malloc (n_out_edges * sizeof(ir_node *));
466 set_irp_ip_outedges(out_edges);
470 void free_ip_outs(void)
472 ir_node **out_edges = get_irp_ip_outedges();
473 if (out_edges != NULL) {
475 set_irp_ip_outedges(NULL);
477 irp->outs_state = outs_none;
481 void free_outs(ir_graph *irg) {
483 /* current_ir_graph->outs_state = outs_none; */
484 irg->outs_state = outs_none;
488 memset(irg->outs, 0, irg->n_outs);
489 #endif /* defined DEBUG_libfirm */
494 #endif /* defined DEBUG_libfirm */
498 /* when debugging, *always* reset all nodes' outs! irg->outs might
499 have been lying to us */
500 irg_walk_graph (irg, reset_outs, NULL, NULL);
501 #endif /* defined DEBUG_libfirm */