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4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
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9 * packaging of this file.
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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 Clique calculation for chordal ifg.
23 * @author Sebastian Hack
35 #include "irgraph_t.h"
41 #include "beintlive_t.h"
43 #include "beifg_impl.h"
44 #include "bechordal_t.h"
46 typedef struct _cli_head_t {
47 struct list_head list;
48 struct _cli_head_t *next_cli_head;
53 typedef struct _ifg_clique_t {
54 const be_ifg_impl_t *impl;
55 const be_chordal_env_t *env;
58 cli_head_t *curr_cli_head;
61 typedef struct _cli_element_t {
62 struct list_head list;
66 typedef struct _cli_iter_t {
67 const ifg_clique_t *ifg;
68 cli_head_t *curr_cli_head;
69 cli_element_t *curr_cli_element;
70 const ir_node *curr_irn;
71 bitset_t *visited_neighbours;
72 bitset_t *visited_nodes;
75 /* PRIVATE FUNCTIONS */
76 static cli_head_t *get_new_cli_head(ifg_clique_t *ifg)
79 cli_head_t *new_cli_head;
81 if (ifg->cli_root == NULL)
83 new_cli_head = OALLOC(&ifg->obst, cli_head_t);
84 INIT_LIST_HEAD(&new_cli_head->list);
85 ifg->cli_root = new_cli_head;
89 cli_head = ifg->cli_root;
90 while (!(cli_head->next_cli_head == NULL))
92 cli_head = cli_head->next_cli_head;
94 new_cli_head = OALLOC(&ifg->obst, cli_head_t);
95 INIT_LIST_HEAD(&new_cli_head->list);
96 cli_head->next_cli_head = new_cli_head;
99 new_cli_head->min = NULL;
100 new_cli_head->max = NULL;
101 new_cli_head->next_cli_head = NULL;
102 ifg->curr_cli_head = new_cli_head;
107 static cli_element_t *get_new_cli_element(ifg_clique_t *ifg)
109 cli_element_t *cli_element;
111 cli_element = OALLOC(&ifg->obst, cli_element_t);
112 INIT_LIST_HEAD(&cli_element->list);
117 static void write_clique(ir_nodeset_t *live_set, ifg_clique_t *ifg)
122 ir_node *max_node = NULL;
123 ir_node *min_node = NULL;
124 cli_element_t *new_element = NULL;
125 cli_element_t *element = NULL;
126 cli_head_t *cli_head = get_new_cli_head(ifg);
128 ir_nodeset_iterator_t iter;
130 foreach_ir_nodeset(live_set, live_irn, iter)
132 /* test if node is max or min dominator*/
133 test_node = live_irn;
134 if (max_node == NULL)
136 max_node = test_node;
137 min_node = test_node;
141 test_int = value_dominates(test_node, max_node);
144 max_node = test_node;
146 test_int = value_dominates(min_node, test_node);
149 min_node = test_node;
153 list_for_each_entry(cli_element_t, element, &cli_head->list, list){
154 if (element->irn == live_irn){
161 new_element = get_new_cli_element(ifg);
162 new_element->irn = live_irn;
163 list_add(&new_element->list, &cli_head->list) ;
167 cli_head->min = min_node;
168 cli_head->max = max_node;
171 static cli_head_t *get_next_cli_head(const ir_node *irn, cli_iter_t *it) /* ...containing the node *irn */
174 cli_element_t *element;
176 int is_dominated_by_max;
178 if (it->curr_cli_head == NULL || it->curr_cli_head->next_cli_head == NULL) /* way back of recursion or this is the last clique */
180 it->curr_cli_head = NULL;
184 head = it->curr_cli_head->next_cli_head;
186 is_dominated_by_max = value_dominates(head->max, irn);
188 if ((is_dominated_by_max) || (irn == head->max)) /* node could be in clique */
190 /* check if node is in clique */
191 list_for_each_entry(cli_element_t, element, &head->list, list)
193 if (&element->list != &head->list)
195 if (element->irn == irn)
197 /* node is in clique */
198 it->curr_cli_head = head;
199 /* needed because the next element is searched with list.next of it->curr_cli_element */
200 it->curr_cli_element = (void *) head;
206 if (it->curr_cli_head != head) /*node was not in clique */
208 it->curr_cli_head = head;
209 head = get_next_cli_head(irn, it);
214 it->curr_cli_head = head;
215 head = get_next_cli_head(irn, it);
220 /* ... of the current clique, returns NULL if there were no more elements ..*/
221 static cli_element_t *get_next_element(const ir_node *irn, cli_iter_t *it)
223 cli_element_t *element = it->curr_cli_element;
224 cli_head_t *head = it->curr_cli_head;
226 if (!head || it->curr_cli_element == NULL) /* way back of recursion or there are no more heads */
228 it->curr_cli_element = NULL;
233 element = list_entry(element->list.next, cli_element_t, list);
235 if (&element->list == &head->list) /* Clique has no more elements */
237 head = get_next_cli_head(irn, it);
238 element = get_next_element(irn, it);
241 if (element && element->irn == irn) /* the node you are searching neighbors for */
243 it->curr_cli_element = element;
244 element = get_next_element(irn, it);
247 it->curr_cli_element = element;
253 static void find_nodes(const ifg_clique_t *ifg, cli_iter_t *it)
255 cli_element_t *element;
256 cli_head_t *cli_head = ifg->cli_root;
258 bitset_t *bitset_visnodes = bitset_malloc(get_irg_last_idx(ifg->env->irg));
260 it->visited_nodes = bitset_visnodes;
261 it->curr_cli_head = cli_head;
263 assert(cli_head && "There is no root entry to work on!");
265 if (cli_head->list.next != &cli_head->list) /* if cli_head contains an element */
267 element = list_entry(cli_head->list.next, cli_element_t, list);
268 it->curr_cli_element = element;
272 static ir_node *get_next_node(cli_iter_t *it)
274 cli_head_t *cli_head = NULL;
275 cli_element_t *element = it->curr_cli_element;
282 if (!(&it->curr_cli_head->list == element->list.next))
285 element = list_entry(element->list.next, cli_element_t, list);
286 it->curr_cli_element = element;
288 else /* reached end of clique */
290 cli_head = it->curr_cli_head;
291 if (!(cli_head->next_cli_head == NULL))
294 cli_head = cli_head->next_cli_head;
295 it->curr_cli_head = cli_head;
296 element = list_entry(cli_head->list.next, cli_element_t, list);
297 it->curr_cli_element = element;
301 it->curr_cli_head = NULL;
302 it->curr_cli_element = NULL;
308 if (bitset_is_set(it->visited_nodes, get_irn_idx(irn)))
310 irn = get_next_node(it);
314 bitset_set(it->visited_nodes, get_irn_idx(irn));
321 static void find_neighbour_walker(ir_node *bl, void *data)
323 ifg_clique_t *ifg = data;
324 struct list_head *head = get_block_border_head(ifg->env, bl);
329 ir_nodeset_init(&live);
331 assert(is_Block(bl) && "There is no block to work on.");
333 foreach_border_head(head, b) /* follow the borders of the block */
335 ir_node *irn = b->irn;
337 if (b->is_def) /* b is a new node */
339 ir_nodeset_insert(&live, irn);
347 if (was_def == 1) /* if there is a USE after a DEF... */
349 write_clique(&live, ifg); /* ...add the clique. */
352 ir_nodeset_remove(&live, irn);
355 ir_nodeset_destroy(&live);
358 static void find_first_neighbour(const ifg_clique_t *ifg, cli_iter_t *it, const ir_node *irn)
360 cli_head_t *cli_head = ifg->cli_root;
361 cli_element_t *element;
362 bitset_t *bitset_visneighbours = bitset_malloc(get_irg_last_idx(ifg->env->irg));
364 int is_dominated_by_max = 0;
365 int is_in_clique = 0;
367 it->curr_cli_head = cli_head;
369 it->visited_neighbours = bitset_visneighbours;
371 assert(cli_head && "There is no root entry for a cli_head.");
373 is_dominated_by_max = value_dominates(cli_head->max, irn);
375 if ((is_dominated_by_max) || (irn == cli_head->max)) /* node could be in clique */
377 /* check if node is in clique */
378 list_for_each_entry(cli_element_t, element, &cli_head->list, list)
380 if (element->irn == irn) /* node is in clique */
382 it->curr_cli_element = (void *) cli_head; /* needed because the next element is searched with list.next of it->curr_cli_element */
384 element = get_next_element(irn, it);
391 cli_head = get_next_cli_head(irn, it);
392 element = get_next_element(irn, it);
395 it->curr_cli_element = element;
399 static ir_node *get_next_neighbour(cli_iter_t *it)
402 const ir_node *irn = it->curr_irn;
404 if (it->curr_cli_element != NULL)
405 res = it->curr_cli_element->irn;
409 it->curr_cli_element = get_next_element(irn, it);
413 if (bitset_contains_irn(it->visited_neighbours, res))
415 res = get_next_neighbour(it);
419 bitset_set(it->visited_neighbours, get_irn_idx(res));
427 /* PUBLIC FUNCTIONS */
429 static void ifg_clique_free(void *self)
431 ifg_clique_t *ifg = self;
432 obstack_free(&ifg->obst, NULL);
437 static int ifg_clique_connected(const void *self, const ir_node *a, const ir_node *b)
439 const ifg_clique_t *ifg = self;
444 find_first_neighbour(ifg, &it, a);
446 irn = get_next_neighbour(&it);
454 irn = get_next_neighbour(&it);
460 static ir_node *ifg_clique_neighbours_begin(const void *self, void *iter, const ir_node *irn)
462 find_first_neighbour(self, iter, irn);
463 return get_next_neighbour(iter);
466 static ir_node *ifg_clique_neighbours_next(const void *self, void *iter)
469 return get_next_neighbour(iter);
472 static void ifg_clique_neighbours_break(const void *self, void *iter)
474 cli_iter_t *it = iter;
477 bitset_free(it->visited_neighbours);
480 static ir_node *ifg_clique_nodes_begin(const void *self, void *iter)
482 find_nodes(self, iter);
483 return get_next_node(iter);
486 static ir_node *ifg_clique_nodes_next(const void *self, void *iter)
489 return get_next_node(iter);
492 static void ifg_clique_nodes_break(const void *self, void *iter)
494 cli_iter_t *it = iter;
497 bitset_free(it->visited_nodes);
500 static int ifg_clique_degree(const void *self, const ir_node *irn)
505 find_first_neighbour(self, &it, irn);
507 irn = get_next_neighbour(&it);
511 irn = get_next_neighbour(&it);
517 static const be_ifg_impl_t ifg_clique_impl = {
522 ifg_clique_connected,
523 ifg_clique_neighbours_begin,
524 ifg_clique_neighbours_next,
525 ifg_clique_neighbours_break,
526 ifg_clique_nodes_begin,
527 ifg_clique_nodes_next,
528 ifg_clique_nodes_break,
535 be_ifg_t *be_ifg_clique_new(const be_chordal_env_t *env)
537 ifg_clique_t *ifg = XMALLOC(ifg_clique_t);
539 ifg->impl = &ifg_clique_impl;
542 ifg->cli_root = NULL;
543 obstack_init(&ifg->obst);
545 dom_tree_walk_irg(env->irg, find_neighbour_walker, NULL, ifg);
547 obstack_finish(&ifg->obst);
548 return (be_ifg_t *) ifg;