2 * This file is part of libFirm.
3 * Copyright (C) 2012 University of Karlsruhe.
8 * @brief Blockwise walker implementation
14 #include "irgraph_t.h"
22 #define _get_walk_arity(env, node) \
23 ((env)->follow_deps ? get_irn_ins_or_deps((node)) : get_irn_arity((node)))
24 #define _get_walk_irn_n(env, node, pos) \
25 ((env)->follow_deps ? get_irn_in_or_dep((node), (pos)) : get_irn_n((node), (pos)))
28 * Metadata for block walker
30 typedef struct blk_collect_data_t {
31 struct obstack obst; /**< obstack to allocate objects on */
32 pset *blk_map; /**< Hash map: Block -> List */
33 ir_node **blk_list; /**< the Block list */
34 unsigned follow_deps : 1; /**< follow dependency edges */
38 * An entry for a block in the blk_map
40 typedef struct block_entry_t {
41 ir_node *block; /**< the block */
42 ir_node **phi_list; /**< the list of Phi instruction */
43 ir_node **df_list; /**< the list of data flow instruction */
44 ir_node **cf_list; /**< the list of control flow instructions */
45 ir_node **entry_list; /**< list of all block entries */
49 * compare two block_entries
51 static int addr_cmp(const void *elt, const void *key)
53 const block_entry_t *e1 = (const block_entry_t*)elt;
54 const block_entry_t *e2 = (const block_entry_t*)key;
56 return e1->block != e2->block;
60 * Returns the associates block_entry_t for an block
62 static block_entry_t *block_find_entry(ir_node *block, blk_collect_data_t *ctx)
68 elem = (block_entry_t*)pset_find(ctx->blk_map, &key, hash_ptr(block));
72 elem = OALLOC(&ctx->obst, block_entry_t);
75 elem->phi_list = NEW_ARR_F(ir_node *, 0);
76 elem->df_list = NEW_ARR_F(ir_node *, 0);
77 elem->cf_list = NEW_ARR_F(ir_node *, 0);
78 elem->entry_list = NEW_ARR_F(ir_node *, 0);
80 return (block_entry_t*)pset_insert(ctx->blk_map, elem, hash_ptr(block));
84 * Traverse a block in pre order.
86 static void traverse_block_pre(ir_node *block, block_entry_t *entry, irg_walk_func *pre, void *env)
90 for (j = ARR_LEN(entry->cf_list); j > 0;) {
91 ir_node *node = entry->cf_list[--j];
95 for (j = ARR_LEN(entry->df_list); j > 0;) {
96 ir_node *node = entry->df_list[--j];
100 for (j = ARR_LEN(entry->phi_list); j > 0;) {
101 ir_node *node = entry->phi_list[--j];
109 * Traverse a block in post order.
111 static void traverse_block_post(ir_node *block, block_entry_t *entry,
112 irg_walk_func *post, void *env)
118 for (j = 0, n = ARR_LEN(entry->phi_list); j < n; ++j) {
119 ir_node *node = entry->phi_list[j];
123 for (j = 0, n = ARR_LEN(entry->df_list); j < n; ++j) {
124 ir_node *node = entry->df_list[j];
128 for (j = 0, n = ARR_LEN(entry->cf_list); j < n; ++j) {
129 ir_node *node = entry->cf_list[j];
135 * traverse the pre order only, from End to Start
137 static void traverse_pre(blk_collect_data_t *blks, irg_walk_func *pre, void *env)
141 for (i = ARR_LEN(blks->blk_list); i > 0;) {
142 ir_node *block = blks->blk_list[--i];
143 block_entry_t *entry = block_find_entry(block, blks);
145 traverse_block_pre(block, entry, pre, env);
147 DEL_ARR_F(entry->entry_list);
148 DEL_ARR_F(entry->phi_list);
149 DEL_ARR_F(entry->df_list);
150 DEL_ARR_F(entry->cf_list);
155 * traverse the post order only, from Start to End
157 static void traverse_post(blk_collect_data_t *blks, irg_walk_func *post, void *env)
161 for (i = 0, k = ARR_LEN(blks->blk_list); i < k; ++i) {
162 ir_node *block = blks->blk_list[i];
163 block_entry_t *entry = block_find_entry(block, blks);
165 traverse_block_post(block, entry, post, env);
167 DEL_ARR_F(entry->entry_list);
168 DEL_ARR_F(entry->phi_list);
169 DEL_ARR_F(entry->df_list);
170 DEL_ARR_F(entry->cf_list);
177 static void traverse_both(blk_collect_data_t *blks, irg_walk_func *pre, irg_walk_func *post, void *env)
181 for (i = ARR_LEN(blks->blk_list); i > 0;) {
182 ir_node *block = blks->blk_list[--i];
183 block_entry_t *entry = block_find_entry(block, blks);
185 traverse_block_pre(block, entry, pre, env);
189 traverse_post(blks, post, env);
195 static void traverse_blocks(blk_collect_data_t *blks, irg_walk_func *pre, irg_walk_func *post, void *env)
197 if (!post) traverse_pre (blks, pre, env);
198 else if (!pre) traverse_post(blks, post, env);
199 else traverse_both(blks, pre, post, env);
202 typedef struct dom_traversal_t {
203 blk_collect_data_t *blks;
210 * Dom block walker. Visit all nodes in pre oder.
212 static void dom_block_visit_pre(ir_node *block, void *env)
214 dom_traversal_t *ctx = (dom_traversal_t*)env;
215 block_entry_t *entry = block_find_entry(block, ctx->blks);
217 traverse_block_pre(block, entry, ctx->pre, ctx->env);
221 * Dom block walker. Visit all nodes in post oder.
223 static void dom_block_visit_post(ir_node *block, void *env)
225 dom_traversal_t *ctx = (dom_traversal_t*)env;
226 block_entry_t *entry = block_find_entry(block, ctx->blks);
228 traverse_block_post(block, entry, ctx->post, ctx->env);
232 * Dom block walker. Visit all nodes in pre oder, than in post order.
234 static void dom_block_visit_both(ir_node *block, void *env)
236 dom_traversal_t *ctx = (dom_traversal_t*)env;
237 block_entry_t *entry = block_find_entry(block, ctx->blks);
239 traverse_block_pre(block, entry, ctx->pre, ctx->env);
240 traverse_block_post(block, entry, ctx->post, ctx->env);
244 * Do the traversal in the dominator tree in top-down order.
246 static void traverse_dom_blocks_top_down(blk_collect_data_t* blks, irg_walk_func *pre, irg_walk_func *post, void *env)
255 if (pre != NULL && post != NULL)
256 dom_tree_walk_irg(current_ir_graph, dom_block_visit_both, NULL, &ctx);
257 else if (pre != NULL)
258 dom_tree_walk_irg(current_ir_graph, dom_block_visit_pre, NULL, &ctx);
259 else if (post != NULL)
260 dom_tree_walk_irg(current_ir_graph, dom_block_visit_post, NULL, &ctx);
264 * walks over the graph and collects all blocks and all block entries
266 static void collect_walk(ir_node *node, blk_collect_data_t *env)
269 block_entry_t *entry;
272 mark_irn_visited(node);
274 if (is_Block(node)) {
275 /* predecessors of a block are control flow nodes */
276 for (i = _get_walk_arity(env, node) - 1; i >= 0; --i) {
277 ir_node *pred = _get_walk_irn_n(env, node, i);
278 ir_node *blk = get_nodes_block(pred);
280 if (!irn_visited(pred)) {
281 collect_walk(pred, env);
283 /* control flow predecessors are always block inputs */
284 entry = block_find_entry(blk, env);
285 ARR_APP1(ir_node *, entry->entry_list, pred);
289 /* it's a block, put it into the block list */
290 if (node == get_irg_end_block(current_ir_graph)) {
291 /* Put the end block always last. If we don't do it here,
292 * it might be placed elsewhere if the graph contains
296 ARR_APP1(ir_node *, env->blk_list, node);
300 block = get_nodes_block(node);
302 if (!irn_visited(block))
303 collect_walk(block, env);
305 is_phi = is_Phi(node);
306 for (i = _get_walk_arity(env, node) - 1; i >= 0; --i) {
307 ir_node *pred = _get_walk_irn_n(env, node, i);
309 if (!irn_visited(pred)) {
310 collect_walk(pred, env);
312 /* BEWARE: predecessors of End nodes might be blocks */
313 if (!is_Block(pred)) {
314 ir_node *blk = get_nodes_block(pred);
317 * Note that Phi predecessors are always block entries
318 * because Phi edges are always "outside" a block
320 if (block != blk || is_phi) {
321 entry = block_find_entry(blk, env);
322 ARR_APP1(ir_node *, entry->entry_list, pred);
331 * walks over the nodes of a block
332 * and collects them into the right list
334 static void collect_blks_lists(ir_node *node, ir_node *block,
335 block_entry_t *entry, blk_collect_data_t *env)
339 mark_irn_visited(node);
342 * Do not descent into Phi predecessors, these are always
343 * outside the current block because Phi edges are always
346 if (! is_Phi(node)) {
347 for (i = _get_walk_arity(env, node) - 1; i >= 0; --i) {
348 ir_node *pred = _get_walk_irn_n(env, node, i);
350 /* BEWARE: predecessors of End nodes might be blocks */
351 if (!is_Block(pred)) {
352 ir_node *blk = get_nodes_block(pred);
354 if (!irn_visited(pred)) {
357 collect_blks_lists(pred, block, entry, env);
362 ARR_APP1(ir_node *, entry->phi_list, node);
366 if (get_irn_mode(node) == mode_X) {
367 ARR_APP1(ir_node *, entry->cf_list, node);
369 ARR_APP1(ir_node *, entry->df_list, node);
374 * walk over the graph and collect all lists
376 static void collect_lists(blk_collect_data_t *env)
379 ir_node *block, *node;
380 block_entry_t *entry;
382 inc_irg_visited(current_ir_graph);
384 for (i = ARR_LEN(env->blk_list); i > 0;) {
385 block = env->blk_list[--i];
386 entry = block_find_entry(block, env);
388 for (j = ARR_LEN(entry->entry_list); j > 0;) {
389 node = entry->entry_list[--j];
391 /* a entry might already be visited due to Phi loops */
392 if (node->visited < current_ir_graph->visited)
393 collect_blks_lists(node, block, entry, env);
399 * Intra procedural graph walker over blocks.
401 static void do_irg_walk_blk(ir_graph *irg, irg_walk_func *pre,
402 irg_walk_func *post, void *env, unsigned follow_deps,
403 void (*traverse)(blk_collect_data_t* blks, irg_walk_func *pre, irg_walk_func *post, void *env))
405 ir_node *end_node = get_irg_end(irg);
406 ir_node *end_blk = get_irg_end_block(irg);
407 blk_collect_data_t blks;
408 block_entry_t *entry;
410 obstack_init(&blks.obst);
411 blks.blk_map = new_pset(addr_cmp, 1);
412 blks.blk_list = NEW_ARR_F(ir_node *, 0);
413 blks.follow_deps = follow_deps != 0;
415 /* first step: traverse the graph and fill the lists */
416 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
417 inc_irg_visited(irg);
418 collect_walk(end_node, &blks);
420 /* add the end block */
421 ARR_APP1(ir_node *, blks.blk_list, end_blk);
423 /* and the end node */
424 entry = block_find_entry(end_blk, &blks);
425 ARR_APP1(ir_node *, entry->entry_list, end_node);
427 collect_lists(&blks);
429 /* second step: traverse the list */
430 traverse(&blks, pre, post, env);
432 DEL_ARR_F(blks.blk_list);
433 del_pset(blks.blk_map);
434 obstack_free(&blks.obst, NULL);
436 ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
439 void irg_walk_blkwise_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
441 ir_graph * rem = current_ir_graph;
443 hook_irg_walk_blkwise(irg, (generic_func *)pre, (generic_func *)post);
444 current_ir_graph = irg;
445 do_irg_walk_blk(irg, pre, post, env, 0, traverse_blocks);
446 current_ir_graph = rem;
449 void irg_walk_in_or_dep_blkwise_graph(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
451 ir_graph * rem = current_ir_graph;
453 hook_irg_walk_blkwise(irg, (generic_func *)pre, (generic_func *)post);
454 current_ir_graph = irg;
455 do_irg_walk_blk(irg, pre, post, env, 1, traverse_blocks);
456 current_ir_graph = rem;
459 void irg_walk_blkwise_dom_top_down(ir_graph *irg, irg_walk_func *pre, irg_walk_func *post, void *env)
461 ir_graph * rem = current_ir_graph;
463 hook_irg_walk_blkwise(irg, (generic_func *)pre, (generic_func *)post);
464 current_ir_graph = irg;
465 do_irg_walk_blk(irg, pre, post, env, 0, traverse_dom_blocks_top_down);
466 current_ir_graph = rem;