2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
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 MIN-algorithm with some twists (aka belady spiller v3)
23 * @author Matthias Braun
28 * - handle phis correctly, decide whether we should spill them ~ok
29 * - merge multiple start worksets of blocks ~ok
30 * - how to and when to do the tentative phase...
42 #include "iredges_t.h"
50 #include "bespilloptions.h"
51 #include "besched_t.h"
55 #define EXPENSIVE_CHECKS
58 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
60 typedef struct loop_edge_t loop_edge_t;
67 typedef struct loop_info_t loop_info_t;
70 loop_edge_t *entry_edges;
71 loop_edge_t *exit_edges;
72 size_t max_register_pressure;
75 typedef struct worklist_entry_t worklist_entry_t;
76 struct worklist_entry_t {
77 struct list_head head;
79 ir_node *reload_point;
80 ir_loop *unused_livethrough_loop;
83 #define foreach_worklist(entry, wl) list_for_each_entry(worklist_entry_t, entry, &(wl)->live_values, head)
85 typedef struct worklist_t worklist_t;
87 struct list_head live_values;
92 typedef struct block_info_t block_info_t;
94 worklist_t *start_worklist;
95 worklist_t *end_worklist;
98 /** The register class we currently run on. */
99 static const arch_register_class_t *cls;
100 static struct obstack obst;
101 static spill_env_t *senv;
102 static size_t n_regs;
103 static size_t max_register_pressure;
104 static bool tentative_mode;
105 static bool do_push_unused_livethroughs;
106 /** Execution frequency for the current graph. */
107 static ir_exec_freq *exec_freq;
108 static ir_visited_t worklist_visited;
110 static bool should_have_reached_fixpoint;
113 static worklist_t *new_worklist(void)
115 worklist_t *worklist = obstack_alloc(&obst, sizeof(worklist[0]));
116 memset(worklist, 0, sizeof(worklist[0]));
118 INIT_LIST_HEAD(&worklist->live_values);
119 worklist->n_live_values = 0;
124 static void mark_irn_not_visited(ir_node *node)
126 set_irn_visited(node, get_irg_visited(current_ir_graph) - 1);
129 static bool worklist_contains(const ir_node *node)
131 return irn_visited(node);
134 static block_info_t *get_block_info(ir_node *block)
136 block_info_t *info = get_irn_link(block);
140 info = obstack_alloc(&obst, sizeof(info[0]));
141 memset(info, 0, sizeof(info[0]));
142 set_irn_link(block, info);
146 static void deactivate_worklist(const worklist_t *worklist)
148 worklist_entry_t *entry;
150 foreach_worklist(entry, worklist) {
151 assert(worklist_contains(entry->value));
152 mark_irn_not_visited(entry->value);
153 set_irn_link(entry->value, NULL);
157 static void activate_worklist(const worklist_t *worklist)
159 worklist_entry_t *entry;
161 foreach_worklist(entry, worklist) {
162 assert(!worklist_contains(entry->value));
163 mark_irn_visited(entry->value);
164 set_irn_link(entry->value, entry);
169 * duplicate a worklist and directly activates it
171 static void fill_and_activate_worklist(worklist_t *new_worklist,
172 const worklist_t *worklist, ir_node *block, ir_node *succ_block,
175 ir_node *reload_point = NULL;
176 size_t n_live_values = 0;
177 worklist_entry_t *entry;
179 if (succ_block != NULL &&
180 (get_Block_n_cfgpreds(succ_block) > 1
181 || get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) > 1)) {
182 reload_point = be_get_end_of_block_insertion_point(block);
185 foreach_worklist(entry, worklist) {
186 ir_node *value = entry->value;
187 worklist_entry_t *new_entry;
189 if (new_worklist->n_live_values >= n_regs)
192 if (is_Phi(value) && get_nodes_block(value) == succ_block) {
193 value = get_Phi_pred(value, succ_pos);
195 /* can happen for unknown phi preds */
196 if (!arch_irn_consider_in_reg_alloc(cls, value))
200 if (irn_visited_else_mark(value))
203 new_entry = obstack_alloc(&obst, sizeof(new_entry[0]));
204 memset(new_entry, 0, sizeof(new_entry[0]));
206 new_entry->value = value;
207 if (reload_point != NULL) {
208 new_entry->reload_point = reload_point;
210 new_entry->reload_point = entry->reload_point;
213 list_add_tail(&new_entry->head, &new_worklist->live_values);
216 set_irn_link(value, new_entry);
217 new_worklist->n_live_values++;
221 static worklist_t *duplicate_worklist(const worklist_t *worklist)
223 worklist_t *new_worklist;
224 struct list_head *entry;
226 new_worklist = obstack_alloc(&obst, sizeof(new_worklist[0]));
227 memset(new_worklist, 0, sizeof(new_worklist[0]));
228 INIT_LIST_HEAD(&new_worklist->live_values);
229 new_worklist->n_live_values = worklist->n_live_values;
231 list_for_each(entry, &worklist->live_values) {
232 worklist_entry_t *wl_entry = list_entry(entry, worklist_entry_t, head);
233 worklist_entry_t *new_entry
234 = obstack_alloc(&obst, sizeof(new_entry[0]));
236 memcpy(new_entry, wl_entry, sizeof(new_entry[0]));
237 list_add_tail(&new_entry->head, &new_worklist->live_values);
244 static void print_worklist(const worklist_t *worklist, int level)
246 struct list_head *entry;
248 DB((dbg, level, "%d values: ", worklist->n_live_values));
249 list_for_each(entry, &worklist->live_values) {
250 worklist_entry_t *wl_entry
251 = list_entry(entry, worklist_entry_t, head);
253 DB((dbg, level, "%+F ", wl_entry->value));
260 * Clear the link fields of a loop and all
263 * @param loop the root loop
265 static void clear_loop_info(ir_loop *loop)
267 int n_elements = get_loop_n_elements(loop);
271 for (i = 0; i < n_elements; ++i) {
272 loop_element element = get_loop_element(loop, i);
273 if (*element.kind != k_ir_loop)
276 clear_loop_info(element.son);
280 static loop_info_t *get_loop_info(ir_loop *loop)
282 loop_info_t *info = loop->link;
286 info = obstack_alloc(&obst, sizeof(info[0]));
287 memset(info, 0, sizeof(info[0]));
294 * constructs loop in+out edges when called in a block walker
296 static void construct_loop_edges(ir_node *block, void *data)
298 int n_cfgpreds = get_Block_n_cfgpreds(block);
299 ir_loop *loop = get_irn_loop(block);
304 for (i = 0; i < n_cfgpreds; ++i) {
305 ir_node *cfgpred_block = get_Block_cfgpred_block(block, i);
306 ir_loop *cfgpred_loop = get_irn_loop(cfgpred_block);
311 if (cfgpred_loop == loop)
314 /* critical edges are splitted, so we can't jump from 1 loop
315 * directly into another without going out of it */
316 assert(get_loop_depth(cfgpred_loop) != get_loop_depth(loop));
318 /* edge out of loop */
319 if (get_loop_depth(cfgpred_loop) > get_loop_depth(loop)) {
324 is_exit_edge = false;
329 /* this might be a jump out/in multiple loops */
331 loop_info_t *l_info = get_loop_info(l);
333 edge = obstack_alloc(&obst, sizeof(edge[0]));
334 memset(edge, 0, sizeof(edge[0]));
339 edge->next = l_info->exit_edges;
340 l_info->exit_edges = edge;
341 assert(get_loop_depth(loop) < get_loop_depth(l));
343 edge->next = l_info->entry_edges;
344 l_info->entry_edges = edge;
345 assert(get_loop_depth(cfgpred_loop) < get_loop_depth(l));
347 l = get_loop_outer_loop(l);
355 static void place_reload(worklist_entry_t *entry)
360 DB((dbg, LEVEL_1, "reload of %+F before %+F\n", entry->value,
361 entry->reload_point));
362 assert(entry->reload_point != NULL);
363 be_add_reload(senv, entry->value, entry->reload_point, cls, 1);
364 entry->reload_point = NULL;
368 * makes sure the worklist contains not more than n_regs - room_needed entries
370 static void make_room(worklist_t *worklist, size_t room_needed)
374 struct list_head *entry;
376 spills_needed = worklist->n_live_values + room_needed - n_regs;
377 if (spills_needed <= 0)
380 entry = worklist->live_values.next;
381 for(i = spills_needed; i > 0; --i) {
382 struct list_head *next = entry->next;
383 worklist_entry_t *wl_entry
384 = list_entry(entry, worklist_entry_t, head);
386 assert(worklist_contains(wl_entry->value));
387 mark_irn_not_visited(wl_entry->value);
388 place_reload(wl_entry);
393 worklist->n_live_values -= spills_needed;
397 * a value was used, so bring it to the back of the worklist (which might
398 * result in a spill of another value).
400 static void val_used(worklist_t *worklist, ir_node *value, ir_node *sched_point)
402 /* already in the worklist? move around, otherwise add at back */
403 worklist_entry_t *entry = get_irn_link(value);
405 assert(arch_irn_consider_in_reg_alloc(cls, value));
407 if (worklist_contains(value)) {
408 assert(entry != NULL);
410 list_del(&entry->head);
413 entry = obstack_alloc(&obst, sizeof(entry[0]));
414 memset(entry, 0, sizeof(entry[0]));
416 entry->value = value;
417 set_irn_link(value, entry);
420 ++worklist->n_live_values;
421 mark_irn_visited(value);
424 entry->reload_point = sched_point;
425 list_add_tail(&entry->head, &worklist->live_values);
428 static void worklist_remove(worklist_t *worklist, ir_node *value)
430 worklist_entry_t *entry = get_irn_link(value);
431 assert(entry != NULL);
432 list_del(&entry->head);
433 --worklist->n_live_values;
435 assert(worklist_contains(value));
436 mark_irn_not_visited(value);
439 static void update_max_pressure(worklist_t *worklist)
441 if (worklist->n_live_values > max_register_pressure)
442 max_register_pressure = worklist->n_live_values;
445 static void do_spilling(ir_node *block, worklist_t *worklist)
449 assert(worklist != NULL);
451 sched_foreach_reverse(block, node) {
455 DB((dbg, LEVEL_2, "\t%+F... ", node));
456 update_max_pressure(worklist);
460 /* TODO: if we have some free registers, then we could decide to
461 * not spill some phis (but not for phis where at least 1 input is
464 /* we have to spill all phis that are not live */
465 sched_foreach_reverse_from(node, node2) {
466 assert(is_Phi(node2));
468 if (worklist_contains(node2))
470 if (!arch_irn_consider_in_reg_alloc(cls, node2))
474 be_spill_phi(senv, node2);
476 DB((dbg, LEVEL_2, "\n"));
480 /* remove values defined by this instruction from the workset. Values
481 * defined but not in the workset need free registers */
482 if (get_irn_mode(node) == mode_T) {
483 const ir_edge_t *edge;
485 foreach_out_edge(node, edge) {
486 ir_node *proj = get_edge_src_irn(edge);
487 if (!arch_irn_consider_in_reg_alloc(cls, proj))
489 if (worklist_contains(proj)) {
490 worklist_remove(worklist, proj);
495 } else if (arch_irn_consider_in_reg_alloc(cls, node)) {
496 if (worklist_contains(node)) {
497 worklist_remove(worklist, node);
503 /* make sure we have enough free registers for the spills */
504 make_room(worklist, n_defs);
506 /* put all values used by the instruction into the workset */
507 arity = get_irn_arity(node);
508 for(i = 0; i < arity; ++i) {
509 ir_node *use = get_irn_n(node, i);
511 if (!arch_irn_consider_in_reg_alloc(cls, use))
514 val_used(worklist, use, node);
517 /* we might have too many values in the worklist now and need to spill
519 make_room(worklist, 0);
522 print_worklist(worklist, LEVEL_2);
523 DB((dbg, LEVEL_2, "\n"));
527 update_max_pressure(worklist);
530 DB((dbg, LEVEL_1, "worklist at begin of %+F:", block));
531 print_worklist(worklist, LEVEL_1);
532 DB((dbg, LEVEL_1, "\n"));
536 static bool worklists_equal(const worklist_t *wl1, const worklist_t *wl2)
538 const struct list_head *i1 = &wl1->live_values;
539 const struct list_head *i2 = &wl2->live_values;
541 for ( ; i1 != &wl1->live_values && i2 != &wl2->live_values;
542 i1 = i1->next, i2 = i2->next) {
543 worklist_entry_t *entry1 = list_entry(i1, worklist_entry_t, head);
544 worklist_entry_t *entry2 = list_entry(i2, worklist_entry_t, head);
546 if (entry1->value != entry2->value)
549 /* both lists at the end */
550 if (i1 != &wl1->live_values || i2 != &wl2->live_values)
556 static bool fill_start_worklist(worklist_t *new_worklist, ir_node *block)
558 double best_execfreq = -1;
559 worklist_t *best_worklist = NULL;
560 ir_node *best_succ_block = NULL;
562 const ir_edge_t *edge;
564 /* construct worklist */
565 foreach_block_succ(block, edge) {
566 ir_node *succ_block = get_edge_src_irn(edge);
567 double execfreq = get_block_execfreq(exec_freq, succ_block);
568 block_info_t *block_info;
569 worklist_t *succ_worklist;
571 if (execfreq < best_execfreq)
574 block_info = get_block_info(succ_block);
575 succ_worklist = block_info->start_worklist;
577 if (succ_worklist == NULL || succ_worklist->visited >= worklist_visited)
580 best_execfreq = execfreq;
581 best_worklist = succ_worklist;
582 best_succ_block = succ_block;
583 best_pos = get_edge_src_pos(edge);
586 if (best_worklist == NULL)
588 best_worklist->visited = worklist_visited;
590 fill_and_activate_worklist(new_worklist, best_worklist, block,
591 best_succ_block, best_pos);
595 static worklist_t *construct_start_worklist(ir_node *block)
597 worklist_t *worklist = new_worklist();
601 while(fill_start_worklist(worklist, block)) {
602 if (worklist->n_live_values >= n_regs)
609 static void process_block(ir_node *block, void *env)
611 block_info_t *block_info;
612 worklist_t *worklist;
616 DB((dbg, LEVEL_1, "Processing %+F\n", block));
618 worklist = construct_start_worklist(block);
619 block_info = get_block_info(block);
622 DB((dbg, LEVEL_1, "worklist at end of %+F:", block));
623 print_worklist(worklist, LEVEL_1);
624 DB((dbg, LEVEL_1, "\n"));
626 if (should_have_reached_fixpoint) {
627 assert(worklists_equal(block_info->end_worklist, worklist));
630 block_info->end_worklist = duplicate_worklist(worklist);
632 do_spilling(block, worklist);
633 deactivate_worklist(worklist);
636 if (should_have_reached_fixpoint) {
637 assert(worklists_equal(block_info->start_worklist, worklist));
640 block_info->start_worklist = worklist;
642 /* we shouldn't have any live values left at the start block */
643 n_preds = get_Block_n_cfgpreds(block);
644 //assert(n_preds != 0 || worklist->n_live_values == 0);
647 typedef union block_or_loop_t block_or_loop_t;
648 union block_or_loop_t {
653 static block_or_loop_t *loop_blocks;
654 static ir_loop *current_loop;
656 static void find_blocks(ir_node *block);
658 static void find_in_loop(ir_loop *loop, ir_node *entry)
660 loop_info_t *loop_info = get_loop_info(loop);
661 block_or_loop_t block_or_loop;
664 /* simply mark 1 block in the loop to indicate that the loop was already
666 ir_node *some_block = loop_info->entry_edges->block;
667 if (Block_block_visited(some_block))
670 block_or_loop.loop = loop;
671 ARR_APP1(block_or_loop_t, loop_blocks, block_or_loop);
675 /* we should be 1 of the entry blocks */
676 loop_edge_t *edge = loop_info->entry_edges;
678 for ( ; edge != NULL; edge = edge->next) {
679 if (edge->block == entry) {
690 /* check all loop successors */
691 for (edge = loop_info->exit_edges; edge != NULL; edge = edge->next) {
692 ir_node *succ = edge->block;
693 ir_loop *succ_loop = get_irn_loop(succ);
695 if (succ_loop == current_loop) {
698 assert(get_loop_depth(succ_loop) < get_loop_depth(current_loop));
703 static void find_blocks(ir_node *block)
705 const ir_edge_t *edge;
706 block_or_loop_t block_or_loop;
708 if (Block_block_visited(block))
711 block_or_loop.block = block;
713 ARR_APP1(block_or_loop_t, loop_blocks, block_or_loop);
714 mark_Block_block_visited(block);
716 foreach_block_succ(block, edge) {
717 ir_node *succ = get_edge_src_irn(edge);
719 /* is it part of the current loop? */
720 ir_loop *loop = get_irn_loop(succ);
721 if (loop != current_loop) {
723 if (get_loop_depth(loop) > get_loop_depth(current_loop)) {
724 find_in_loop(loop, succ);
726 /* parent loop: we're not interested in the block */
735 * append an entry to a worklist. WARNING: The entry must not already be in the
738 static void worklist_append(worklist_t *worklist, ir_node *value,
739 ir_node *reload_point,
740 ir_loop *unused_livethrough_loop)
742 worklist_entry_t *entry;
744 #ifdef EXPENSIVE_CHECKS
745 foreach_worklist(entry, worklist) {
746 assert(entry->value != value);
750 entry = obstack_alloc(&obst, sizeof(*entry));
751 memset(entry, 0, sizeof(entry[0]));
753 entry->value = value;
754 entry->reload_point = reload_point;
755 entry->unused_livethrough_loop = unused_livethrough_loop;
756 list_add_tail(&entry->head, &worklist->live_values);
757 ++worklist->n_live_values;
758 assert(worklist->n_live_values <= n_regs);
761 static void push_unused_livethrough(loop_info_t *loop_info, ir_node *value)
766 /* add the value to all loop exit and entry blocks */
767 for (edge = loop_info->exit_edges; edge != NULL; edge = edge->next) {
769 = get_Block_cfgpred_block(edge->block, edge->pos);
770 const block_info_t *info = get_block_info(block);
771 worklist_t *worklist = info->end_worklist;
772 ir_node *reload_point = NULL;
774 if (worklist->visited >= worklist_visited)
776 worklist->visited = worklist_visited;
778 /* TODO: we need a smarter mechanism here, that makes the reloader place
779 * reload nodes on all loop exits... */
781 worklist_append(worklist, value, reload_point, loop_info->loop);
783 edge = loop_info->entry_edges;
784 for ( ; edge != NULL; edge = edge->next) {
785 ir_node *entry_block = edge->block;
786 const block_info_t *info = get_block_info(entry_block);
787 worklist_t *worklist = info->start_worklist;
789 ir_node *reload_point;
791 if (worklist->visited >= worklist_visited)
793 worklist->visited = worklist_visited;
795 pred_block = get_Block_cfgpred_block(entry_block, edge->pos);
796 reload_point = be_get_end_of_block_insertion_point(pred_block);
798 worklist_append(worklist, value, reload_point, loop_info->loop);
801 set_irn_link(value, NULL);
802 ++loop_info->max_register_pressure;
805 static void push_unused_livethroughs(loop_info_t *loop_info)
809 /* we can only push unused livethroughs if register pressure inside the loop
811 if (loop_info->max_register_pressure >= n_regs)
814 /* find unused livethroughs: register pressure in the loop was low enough
815 * which means that we had no spills which implies that at every point in
817 for (edge = loop_info->exit_edges; edge != NULL; edge = edge->next) {
818 ir_node *block = edge->block;
819 const block_info_t *info = get_block_info(block);
820 worklist_t *start_worklist = info->start_worklist;
822 const block_info_t *exit_info;
823 worklist_t *end_worklist;
824 struct list_head *entry;
826 if (start_worklist == NULL)
829 exit_block = get_Block_cfgpred_block(edge->block, edge->pos);
830 exit_info = get_block_info(exit_block);
831 end_worklist = exit_info->end_worklist;
833 activate_worklist(end_worklist);
834 /* all values contained in the start_worklist, which are not available
835 * in the end_worklist, must be unused livethroughs */
837 list_for_each(entry, &start_worklist->live_values) {
838 worklist_entry_t *wl_entry
839 = list_entry(entry, worklist_entry_t, head);
840 ir_node *value = wl_entry->value;
842 if (loop_info->max_register_pressure >= n_regs)
846 if (!worklist_contains(value)) {
847 /* add it to all loop exits */
848 DB((dbg, LEVEL_2, "Found unused livethrough: %+F (regpressure in loop %d)\n", value, loop_info->max_register_pressure));
849 push_unused_livethrough(loop_info, value);
850 /* the value should now be part of end_worklist, so mark it */
851 mark_irn_visited(value);
855 deactivate_worklist(end_worklist);
859 static void process_block_or_loop(const block_or_loop_t block_or_loop)
861 if (block_or_loop.loop->kind == k_ir_loop) {
862 loop_info_t *loop_info = get_loop_info(block_or_loop.loop);
864 if (do_push_unused_livethroughs)
865 push_unused_livethroughs(loop_info);
867 if (loop_info->max_register_pressure > max_register_pressure)
868 max_register_pressure = loop_info->max_register_pressure;
872 process_block(block_or_loop.block, NULL);
875 static void process_loop(ir_loop *loop)
877 int n_elements = get_loop_n_elements(loop);
879 loop_info_t *loop_info;
883 /* first handle all sub-loops */
884 for (i = 0; i < n_elements; ++i) {
885 loop_element element = get_loop_element(loop, i);
886 if (*element.kind != k_ir_loop)
889 process_loop(element.son);
892 /* create a postorder of the blocks */
893 loop_info = get_loop_info(loop);
894 edge = loop_info->entry_edges;
896 some_block = edge->block;
898 assert(loop == get_irg_loop(current_ir_graph));
899 some_block = get_irg_start_block(current_ir_graph);
902 loop_blocks = NEW_ARR_F(block_or_loop_t, 0);
905 ir_reserve_resources(current_ir_graph, IR_RESOURCE_BLOCK_VISITED);
906 inc_irg_block_visited(current_ir_graph);
907 find_blocks(some_block);
908 /* for endless loops the end-block might be unreachable */
909 if (loop == get_irg_loop(current_ir_graph)) {
910 find_blocks(get_irg_end_block(current_ir_graph));
912 ir_free_resources(current_ir_graph, IR_RESOURCE_BLOCK_VISITED);
914 DB((dbg, LEVEL_3, "Block List for loop %p\n", loop));
915 len = ARR_LEN(loop_blocks);
916 for (i = 0; i < len; ++i) {
917 block_or_loop_t block_or_loop = loop_blocks[i];
918 if (block_or_loop.loop->kind == k_ir_loop) {
919 DB((dbg, LEVEL_3, " L-%p", block_or_loop.loop));
921 DB((dbg, LEVEL_3, " B-%+F", block_or_loop.block));
924 DB((dbg, LEVEL_3, "\n"));
926 max_register_pressure = 0;
928 /* run1: tentative phase */
929 tentative_mode = true;
930 for (i = len-1; i >= 0; --i) {
931 process_block_or_loop(loop_blocks[i]);
934 /* run2: tentative phase - should reach fixpoint */
935 tentative_mode = true;
936 for (i = len-1; i >= 0; --i) {
937 process_block_or_loop(loop_blocks[i]);
941 /* run3: tentative phase - check fixpoint */
942 tentative_mode = true;
943 should_have_reached_fixpoint = true;
944 for (i = len-1; i >= 0; --i) {
945 process_block_or_loop(loop_blocks[i]);
947 should_have_reached_fixpoint = false;
950 /* run4: add spills/reloads */
951 tentative_mode = false;
952 do_push_unused_livethroughs = true;
953 for (i = len-1; i >= 0; --i) {
954 process_block_or_loop(loop_blocks[i]);
956 do_push_unused_livethroughs = false;
958 loop_info->max_register_pressure = max_register_pressure;
959 DB((dbg, LEVEL_2, "Regpressure in loop %p: %u\n", loop,
960 (unsigned) max_register_pressure));
962 DEL_ARR_F(loop_blocks);
965 static void fix_block_borders(ir_node *block, void *data)
967 block_info_t *block_info = get_block_info(block);
968 worklist_t *start_worklist = block_info->start_worklist;
969 int n_cfgpreds = get_Block_n_cfgpreds(block);
970 ir_loop *loop = get_irn_loop(block);
974 assert(start_worklist != NULL);
976 for (i = 0; i < n_cfgpreds; ++i) {
977 ir_node *pred_block = get_Block_cfgpred_block(block, i);
978 block_info_t *pred_block_info = get_block_info(pred_block);
979 worklist_t *end_worklist = pred_block_info->end_worklist;
980 ir_loop *pred_loop = get_irn_loop(pred_block);
981 bool is_loop_entry = false;
982 worklist_entry_t *entry;
984 assert(end_worklist != NULL);
986 if (get_loop_depth(pred_loop) < get_loop_depth(loop)) {
987 is_loop_entry = true;
990 /* reload missing values */
991 activate_worklist(end_worklist);
993 foreach_worklist(entry, start_worklist) {
994 ir_node *value = entry->value;
996 if (!is_loop_entry && entry->unused_livethrough_loop != NULL)
999 if (is_Phi(value) && get_nodes_block(value) == block) {
1000 value = get_irn_n(value, i);
1002 /* we might have unknowns as argument for the phi */
1003 if (!arch_irn_consider_in_reg_alloc(cls, value))
1006 if (worklist_contains(value))
1008 be_add_reload_on_edge(senv, value, block, i, cls, 1);
1011 deactivate_worklist(end_worklist);
1016 * Run the spill algorithm.
1018 * @param birg the graph to run on
1019 * @param ncls the register class to run on
1021 static void be_spill_belady3(be_irg_t *birg, const arch_register_class_t *ncls)
1023 ir_graph *irg = be_get_birg_irg(birg);
1026 n_regs = cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
1028 /* shortcut for register classes with ignore regs only */
1032 worklist_visited = 0;
1033 exec_freq = be_get_birg_exec_freq(birg);
1035 be_clear_links(irg);
1036 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED | IR_RESOURCE_IRN_LINK
1037 | IR_RESOURCE_LOOP_LINK);
1038 inc_irg_visited(irg);
1040 obstack_init(&obst);
1041 senv = be_new_spill_env(birg);
1043 assure_cf_loop(irg);
1044 clear_loop_info(get_irg_loop(irg));
1045 irg_block_walk_graph(irg, construct_loop_edges, NULL, NULL);
1047 process_loop(get_irg_loop(irg));
1049 irg_block_walk_graph(irg, fix_block_borders, NULL, NULL);
1051 ir_free_resources(irg, IR_RESOURCE_IRN_VISITED | IR_RESOURCE_IRN_LINK
1052 | IR_RESOURCE_LOOP_LINK);
1054 be_insert_spills_reloads(senv);
1056 obstack_free(&obst, NULL);
1059 be_delete_spill_env(senv);
1062 void be_init_spillbelady3(void)
1064 static be_spiller_t belady3_spiller = {
1068 be_register_spiller("belady3", &belady3_spiller);
1069 FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady3");
1072 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady3);