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 Beladys spillalgorithm.
23 * @author Daniel Grund, Matthias Braun
32 #include "irprintf_t.h"
38 #include "iredges_t.h"
41 #include "irnodeset.h"
50 #include "bechordal_t.h"
52 #include "beloopana.h"
54 #include "bespillutil.h"
64 #define DBG_WORKSET 128
65 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
67 #define TIME_UNDEFINED 6666
69 //#define LOOK_AT_LOOPDEPTH
72 * An association between a node and a point in time.
74 typedef struct loc_t {
76 unsigned time; /**< A use time (see beuses.h). */
77 bool spilled; /**< the value was already spilled on this path */
80 typedef struct _workset_t {
81 int len; /**< current length */
82 loc_t vals[0]; /**< inlined array of the values/distances in this working set */
85 static struct obstack obst;
86 static const arch_register_class_t *cls;
87 static const be_lv_t *lv;
88 static be_loopana_t *loop_ana;
90 static workset_t *ws; /**< the main workset used while
91 processing a block. */
92 static be_uses_t *uses; /**< env for the next-use magic */
93 static ir_node *instr; /**< current instruction */
94 static unsigned instr_nr; /**< current instruction number
95 (relative to block start) */
96 static spill_env_t *senv; /**< see bespill.h */
97 static ir_node **blocklist;
99 static int move_spills = true;
100 static int respectloopdepth = true;
101 static int improve_known_preds = true;
102 /* factor to weight the different costs of reloading/rematerializing a node
103 (see bespill.h be_get_reload_costs_no_weight) */
104 static int remat_bonus = 10;
106 static const lc_opt_table_entry_t options[] = {
107 LC_OPT_ENT_BOOL ("movespills", "try to move spills out of loops", &move_spills),
108 LC_OPT_ENT_BOOL ("respectloopdepth", "exprimental (outermost loop cutting)", &respectloopdepth),
109 LC_OPT_ENT_BOOL ("improveknownpreds", "experimental (known preds cutting)", &improve_known_preds),
110 LC_OPT_ENT_INT ("rematbonus", "give bonus to rematerialisable nodes", &remat_bonus),
114 static int loc_compare(const void *a, const void *b)
118 return p->time - q->time;
122 * Alloc a new workset on obstack @p ob with maximum size @p max
124 static workset_t *new_workset(void)
126 return OALLOCFZ(&obst, workset_t, vals, n_regs);
130 * Alloc a new instance on obstack and make it equal to @param workset
132 static workset_t *workset_clone(workset_t *workset)
134 workset_t *res = OALLOCF(&obst, workset_t, vals, n_regs);
135 memcpy(res, workset, sizeof(*res) + n_regs * sizeof(res->vals[0]));
140 * Copy workset @param src to @param tgt
142 static void workset_copy(workset_t *dest, const workset_t *src)
144 size_t size = sizeof(*src) + n_regs * sizeof(src->vals[0]);
145 memcpy(dest, src, size);
149 * Overwrites the current content array of @param ws with the
150 * @param count locations given at memory @param locs.
151 * Set the length of @param ws to count.
153 static void workset_bulk_fill(workset_t *workset, int count, const loc_t *locs)
155 workset->len = count;
156 memcpy(&(workset->vals[0]), locs, count * sizeof(locs[0]));
160 * Inserts the value @p val into the workset, iff it is not
161 * already contained. The workset must not be full.
163 static void workset_insert(workset_t *workset, ir_node *val, bool spilled)
167 /* check for current regclass */
168 assert(arch_irn_consider_in_reg_alloc(cls, val));
170 /* check if val is already contained */
171 for (i = 0; i < workset->len; ++i) {
172 loc = &workset->vals[i];
173 if (loc->node == val) {
182 assert(workset->len < n_regs && "Workset already full!");
183 loc = &workset->vals[workset->len];
185 loc->spilled = spilled;
186 loc->time = TIME_UNDEFINED;
191 * Removes all entries from this workset
193 static void workset_clear(workset_t *workset)
199 * Removes the value @p val from the workset if present.
201 static inline void workset_remove(workset_t *workset, ir_node *val)
204 for (i = 0; i < workset->len; ++i) {
205 if (workset->vals[i].node == val) {
206 workset->vals[i] = workset->vals[--workset->len];
212 static inline const loc_t *workset_contains(const workset_t *ws,
217 for (i = 0; i < ws->len; ++i) {
218 if (ws->vals[i].node == val)
226 * Iterates over all values in the working set.
227 * @p ws The workset to iterate
228 * @p v A variable to put the current value in
229 * @p i An integer for internal use
231 #define workset_foreach(ws, v, i) for (i=0; \
232 v=(i < ws->len) ? ws->vals[i].node : NULL, i < ws->len; \
235 #define workset_set_time(ws, i, t) (ws)->vals[i].time=t
236 #define workset_get_time(ws, i) (ws)->vals[i].time
237 #define workset_set_length(ws, length) (ws)->len = length
238 #define workset_get_length(ws) ((ws)->len)
239 #define workset_get_val(ws, i) ((ws)->vals[i].node)
240 #define workset_sort(ws) qsort((ws)->vals, (ws)->len, sizeof((ws)->vals[0]), loc_compare);
242 typedef struct _block_info_t
244 workset_t *start_workset;
245 workset_t *end_workset;
249 static block_info_t *new_block_info(void)
251 return OALLOCZ(&obst, block_info_t);
254 #define get_block_info(block) ((block_info_t *)get_irn_link(block))
255 #define set_block_info(block, info) set_irn_link(block, info)
258 * @return The distance to the next use or 0 if irn has dont_spill flag set
260 static inline unsigned get_distance(ir_node *from, unsigned from_step,
261 const ir_node *def, int skip_from_uses)
267 assert(!arch_irn_is_ignore(def));
269 use = be_get_next_use(uses, from, from_step, def, skip_from_uses);
271 if (USES_IS_INFINITE(time))
272 return USES_INFINITY;
274 /* We have to keep nonspillable nodes in the workingset */
275 if (arch_irn_get_flags(skip_Proj_const(def)) & arch_irn_flags_dont_spill)
278 /* give some bonus to rematerialisable nodes */
279 if (remat_bonus > 0) {
280 costs = be_get_reload_costs_no_weight(senv, def, use.before);
281 assert(costs * remat_bonus < 1000);
282 time += 1000 - (costs * remat_bonus);
289 * Performs the actions necessary to grant the request that:
290 * - new_vals can be held in registers
291 * - as few as possible other values are disposed
292 * - the worst values get disposed
294 * @p is_usage indicates that the values in new_vals are used (not defined)
295 * In this case reloads must be performed
297 static void displace(workset_t *new_vals, int is_usage)
299 ir_node **to_insert = ALLOCAN(ir_node*, n_regs);
300 bool *spilled = ALLOCAN(bool, n_regs);
308 /* 1. Identify the number of needed slots and the values to reload */
310 workset_foreach(new_vals, val, iter) {
311 bool reloaded = false;
313 if (! workset_contains(ws, val)) {
314 DB((dbg, DBG_DECIDE, " insert %+F\n", val));
316 DB((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr));
317 be_add_reload(senv, val, instr, cls, 1);
321 DB((dbg, DBG_DECIDE, " %+F already in workset\n", val));
323 /* remove the value from the current workset so it is not accidently
325 workset_remove(ws, val);
327 spilled[demand] = reloaded;
328 to_insert[demand] = val;
332 /* 2. Make room for at least 'demand' slots */
333 len = workset_get_length(ws);
334 spills_needed = len + demand - n_regs;
335 assert(spills_needed <= len);
337 /* Only make more free room if we do not have enough */
338 if (spills_needed > 0) {
339 ir_node *curr_bb = NULL;
340 workset_t *ws_start = NULL;
343 curr_bb = get_nodes_block(instr);
344 ws_start = get_block_info(curr_bb)->start_workset;
347 DB((dbg, DBG_DECIDE, " disposing %d values\n", spills_needed));
349 /* calculate current next-use distance for live values */
350 for (i = 0; i < len; ++i) {
351 ir_node *val = workset_get_val(ws, i);
352 unsigned dist = get_distance(instr, instr_nr, val, !is_usage);
353 workset_set_time(ws, i, dist);
356 /* sort entries by increasing nextuse-distance*/
359 for (i = len - spills_needed; i < len; ++i) {
360 ir_node *val = ws->vals[i].node;
362 DB((dbg, DBG_DECIDE, " disposing node %+F (%u)\n", val,
363 workset_get_time(ws, i)));
366 if (!USES_IS_INFINITE(ws->vals[i].time)
367 && !ws->vals[i].spilled) {
368 ir_node *after_pos = sched_prev(instr);
369 DB((dbg, DBG_DECIDE, "Spill %+F after node %+F\n", val,
371 be_add_spill(senv, val, after_pos);
376 /* kill the last 'demand' entries in the array */
377 workset_set_length(ws, len - spills_needed);
380 /* 3. Insert the new values into the workset */
381 for (i = 0; i < demand; ++i) {
382 ir_node *val = to_insert[i];
384 workset_insert(ws, val, spilled[i]);
389 AVAILABLE_EVERYWHERE,
395 static unsigned available_in_all_preds(workset_t* const* pred_worksets,
396 size_t n_pred_worksets,
397 const ir_node *value, bool is_local_phi)
400 bool avail_everywhere = true;
401 bool avail_nowhere = true;
403 assert(n_pred_worksets > 0);
405 /* value available in all preds? */
406 for (i = 0; i < n_pred_worksets; ++i) {
408 const workset_t *p_workset = pred_worksets[i];
409 int p_len = workset_get_length(p_workset);
411 const ir_node *l_value;
414 assert(is_Phi(value));
415 l_value = get_irn_n(value, i);
420 for (p_i = 0; p_i < p_len; ++p_i) {
421 const loc_t *p_l = &p_workset->vals[p_i];
422 if (p_l->node != l_value)
430 avail_nowhere = false;
432 avail_everywhere = false;
436 if (avail_everywhere) {
437 assert(!avail_nowhere);
438 return AVAILABLE_EVERYWHERE;
439 } else if (avail_nowhere) {
440 return AVAILABLE_NOWHERE;
442 return AVAILABLE_PARTLY;
446 /** Decides whether a specific node should be in the start workset or not
448 * @param env belady environment
450 * @param node the node to test
451 * @param loop the loop of the node
453 static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node,
454 ir_loop *loop, unsigned available)
456 be_next_use_t next_use;
459 loc.time = USES_INFINITY;
463 if (!arch_irn_consider_in_reg_alloc(cls, node)) {
464 loc.time = USES_INFINITY;
468 /* We have to keep nonspillable nodes in the workingset */
469 if (arch_irn_get_flags(skip_Proj_const(node)) & arch_irn_flags_dont_spill) {
471 DB((dbg, DBG_START, " %+F taken (dontspill node)\n", node, loc.time));
475 next_use = be_get_next_use(uses, first, 0, node, 0);
476 if (USES_IS_INFINITE(next_use.time)) {
477 // the nodes marked as live in shouldn't be dead, so it must be a phi
478 assert(is_Phi(node));
479 loc.time = USES_INFINITY;
480 DB((dbg, DBG_START, " %+F not taken (dead)\n", node));
484 loc.time = next_use.time;
486 if (improve_known_preds) {
487 if (available == AVAILABLE_EVERYWHERE) {
488 DB((dbg, DBG_START, " %+F taken (%u, live in all preds)\n",
491 } else if (available == AVAILABLE_NOWHERE) {
492 DB((dbg, DBG_START, " %+F not taken (%u, live in no pred)\n",
494 loc.time = USES_INFINITY;
499 if (!respectloopdepth || next_use.outermost_loop >= get_loop_depth(loop)) {
500 DB((dbg, DBG_START, " %+F taken (%u, loop %d)\n", node, loc.time,
501 next_use.outermost_loop));
503 loc.time = USES_PENDING;
504 DB((dbg, DBG_START, " %+F delayed (outerdepth %d < loopdepth %d)\n",
505 node, next_use.outermost_loop, get_loop_depth(loop)));
512 * Computes the start-workset for a block with multiple predecessors. We assume
513 * that at least 1 of the predeccesors is a back-edge which means we're at the
514 * beginning of a loop. We try to reload as much values as possible now so they
515 * don't get reloaded inside the loop.
517 static void decide_start_workset(const ir_node *block)
519 ir_loop *loop = get_irn_loop(block);
525 int i, len, ws_count;
526 int free_slots, free_pressure_slots;
529 workset_t **pred_worksets;
530 bool all_preds_known;
532 /* check predecessors */
533 arity = get_irn_arity(block);
534 pred_worksets = ALLOCAN(workset_t*, arity);
535 all_preds_known = true;
536 for (i = 0; i < arity; ++i) {
537 ir_node *pred_block = get_Block_cfgpred_block(block, i);
538 block_info_t *pred_info = get_block_info(pred_block);
540 if (pred_info == NULL) {
541 pred_worksets[i] = NULL;
542 all_preds_known = false;
544 pred_worksets[i] = pred_info->end_workset;
548 /* Collect all values living at start of block */
549 starters = NEW_ARR_F(loc_t, 0);
550 delayed = NEW_ARR_F(loc_t, 0);
552 DB((dbg, DBG_START, "Living at start of %+F:\n", block));
553 first = sched_first(block);
555 /* check all Phis first */
556 sched_foreach(block, node) {
561 if (!arch_irn_consider_in_reg_alloc(cls, node))
564 if (all_preds_known) {
565 available = available_in_all_preds(pred_worksets, arity, node, true);
567 available = AVAILABLE_UNKNOWN;
570 loc = to_take_or_not_to_take(first, node, loop, available);
572 if (! USES_IS_INFINITE(loc.time)) {
573 if (USES_IS_PENDING(loc.time))
574 ARR_APP1(loc_t, delayed, loc);
576 ARR_APP1(loc_t, starters, loc);
578 be_spill_phi(senv, node);
582 /* check all Live-Ins */
583 be_lv_foreach(lv, block, be_lv_state_in, i) {
584 ir_node *node = be_lv_get_irn(lv, block, i);
587 if (all_preds_known) {
588 available = available_in_all_preds(pred_worksets, arity, node, false);
590 available = AVAILABLE_UNKNOWN;
593 loc = to_take_or_not_to_take(first, node, loop, available);
595 if (! USES_IS_INFINITE(loc.time)) {
596 if (USES_IS_PENDING(loc.time))
597 ARR_APP1(loc_t, delayed, loc);
599 ARR_APP1(loc_t, starters, loc);
603 pressure = be_get_loop_pressure(loop_ana, cls, loop);
604 assert(ARR_LEN(delayed) <= (signed)pressure);
605 free_slots = n_regs - ARR_LEN(starters);
606 free_pressure_slots = n_regs - (pressure - ARR_LEN(delayed));
607 free_slots = MIN(free_slots, free_pressure_slots);
609 /* so far we only put nodes into the starters list that are used inside
610 * the loop. If register pressure in the loop is low then we can take some
611 * values and let them live through the loop */
612 DB((dbg, DBG_START, "Loop pressure %d, taking %d delayed vals\n",
613 pressure, free_slots));
614 if (free_slots > 0) {
615 qsort(delayed, ARR_LEN(delayed), sizeof(delayed[0]), loc_compare);
617 for (i = 0; i < ARR_LEN(delayed) && free_slots > 0; ++i) {
619 loc_t *loc = & delayed[i];
621 if (!is_Phi(loc->node)) {
622 /* don't use values which are dead in a known predecessors
623 * to not induce unnecessary reloads */
624 arity = get_irn_arity(block);
625 for (p = 0; p < arity; ++p) {
626 ir_node *pred_block = get_Block_cfgpred_block(block, p);
627 block_info_t *pred_info = get_block_info(pred_block);
629 if (pred_info == NULL)
632 if (!workset_contains(pred_info->end_workset, loc->node)) {
634 " delayed %+F not live at pred %+F\n", loc->node,
641 DB((dbg, DBG_START, " delayed %+F taken\n", loc->node));
642 ARR_APP1(loc_t, starters, *loc);
650 /* spill phis (the actual phis not just their values) that are in this block
651 * but not in the start workset */
652 for (i = ARR_LEN(delayed) - 1; i >= 0; --i) {
653 ir_node *node = delayed[i].node;
654 if (node == NULL || !is_Phi(node) || get_nodes_block(node) != block)
657 DB((dbg, DBG_START, " spilling delayed phi %+F\n", node));
658 be_spill_phi(senv, node);
662 /* Sort start values by first use */
663 qsort(starters, ARR_LEN(starters), sizeof(starters[0]), loc_compare);
665 /* Copy the best ones from starters to start workset */
666 ws_count = MIN(ARR_LEN(starters), n_regs);
668 workset_bulk_fill(ws, ws_count, starters);
670 /* spill phis (the actual phis not just their values) that are in this block
671 * but not in the start workset */
672 len = ARR_LEN(starters);
673 for (i = ws_count; i < len; ++i) {
674 ir_node *node = starters[i].node;
675 if (! is_Phi(node) || get_nodes_block(node) != block)
678 DB((dbg, DBG_START, " spilling phi %+F\n", node));
679 be_spill_phi(senv, node);
684 /* determine spill status of the values: If there's 1 pred block (which
685 * is no backedge) where the value is spilled then we must set it to
687 for (i = 0; i < ws_count; ++i) {
688 loc_t *loc = &ws->vals[i];
689 ir_node *value = loc->node;
693 /* phis from this block aren't spilled */
694 if (get_nodes_block(value) == block) {
695 assert(is_Phi(value));
696 loc->spilled = false;
700 /* determine if value was spilled on any predecessor */
702 for (n = 0; n < arity; ++n) {
703 workset_t *pred_workset = pred_worksets[n];
707 if (pred_workset == NULL)
710 p_len = workset_get_length(pred_workset);
711 for (p = 0; p < p_len; ++p) {
712 loc_t *l = &pred_workset->vals[p];
714 if (l->node != value)
724 loc->spilled = spilled;
729 * For the given block @p block, decide for each values
730 * whether it is used from a register or is reloaded
733 static void process_block(ir_node *block)
738 block_info_t *block_info;
741 /* no need to process a block twice */
742 assert(get_block_info(block) == NULL);
744 /* construct start workset */
745 arity = get_Block_n_cfgpreds(block);
747 /* no predecessor -> empty set */
749 } else if (arity == 1) {
750 /* one predecessor, copy it's end workset */
751 ir_node *pred_block = get_Block_cfgpred_block(block, 0);
752 block_info_t *pred_info = get_block_info(pred_block);
754 assert(pred_info != NULL);
755 workset_copy(ws, pred_info->end_workset);
757 /* multiple predecessors, do more advanced magic :) */
758 decide_start_workset(block);
761 DB((dbg, DBG_DECIDE, "\n"));
762 DB((dbg, DBG_DECIDE, "Decide for %+F\n", block));
764 block_info = new_block_info();
765 set_block_info(block, block_info);
767 DB((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
768 workset_foreach(ws, irn, iter) {
769 DB((dbg, DBG_WSETS, " %+F (%u)\n", irn,
770 workset_get_time(ws, iter)));
773 block_info->start_workset = workset_clone(ws);
775 /* process the block from start to end */
776 DB((dbg, DBG_WSETS, "Processing...\n"));
778 /* TODO: this leaks (into the obstack)... */
779 new_vals = new_workset();
781 sched_foreach(block, irn) {
783 assert(workset_get_length(ws) <= n_regs);
785 /* Phis are no real instr (see insert_starters()) */
789 DB((dbg, DBG_DECIDE, " ...%+F\n", irn));
791 /* set instruction in the workset */
794 /* allocate all values _used_ by this instruction */
795 workset_clear(new_vals);
796 for (i = 0, arity = get_irn_arity(irn); i < arity; ++i) {
797 ir_node *in = get_irn_n(irn, i);
798 if (!arch_irn_consider_in_reg_alloc(cls, in))
801 /* (note that "spilled" is irrelevant here) */
802 workset_insert(new_vals, in, false);
804 displace(new_vals, 1);
806 /* allocate all values _defined_ by this instruction */
807 workset_clear(new_vals);
808 if (get_irn_mode(irn) == mode_T) {
809 const ir_edge_t *edge;
811 foreach_out_edge(irn, edge) {
812 ir_node *proj = get_edge_src_irn(edge);
813 if (!arch_irn_consider_in_reg_alloc(cls, proj))
815 workset_insert(new_vals, proj, false);
818 if (!arch_irn_consider_in_reg_alloc(cls, irn))
820 workset_insert(new_vals, irn, false);
822 displace(new_vals, 0);
827 /* Remember end-workset for this block */
828 block_info->end_workset = workset_clone(ws);
829 DB((dbg, DBG_WSETS, "End workset for %+F:\n", block));
830 workset_foreach(ws, irn, iter)
831 DB((dbg, DBG_WSETS, " %+F (%u)\n", irn,
832 workset_get_time(ws, iter)));
836 * 'decide' is block-local and makes assumptions
837 * about the set of live-ins. Thus we must adapt the
838 * live-outs to the live-ins at each block-border.
840 static void fix_block_borders(ir_node *block, void *data)
842 workset_t *start_workset;
848 DB((dbg, DBG_FIX, "\n"));
849 DB((dbg, DBG_FIX, "Fixing %+F\n", block));
851 arity = get_irn_arity(block);
852 /* can happen for endless loops */
856 start_workset = get_block_info(block)->start_workset;
858 /* process all pred blocks */
859 for (i = 0; i < arity; ++i) {
860 ir_node *pred = get_Block_cfgpred_block(block, i);
861 workset_t *pred_end_workset = get_block_info(pred)->end_workset;
864 DB((dbg, DBG_FIX, " Pred %+F\n", pred));
866 /* spill all values not used anymore */
867 workset_foreach(pred_end_workset, node, iter) {
871 workset_foreach(start_workset, n2, iter2) {
876 /* note that we do not look at phi inputs, becuase the values
877 * will be either live-end and need no spill or
878 * they have other users in which must be somewhere else in the
885 if (move_spills && be_is_live_in(lv, block, node)
886 && !pred_end_workset->vals[iter].spilled) {
887 ir_node *insert_point;
889 insert_point = be_get_end_of_block_insertion_point(pred);
890 insert_point = sched_prev(insert_point);
892 insert_point = block;
894 DB((dbg, DBG_SPILL, "Spill %+F after %+F\n", node,
896 be_add_spill(senv, node, insert_point);
900 /* reload missing values in predecessors, add missing spills */
901 workset_foreach(start_workset, node, iter) {
902 const loc_t *l = &start_workset->vals[iter];
903 const loc_t *pred_loc;
905 /* if node is a phi of the current block we reload
906 * the corresponding argument, else node itself */
907 if (is_Phi(node) && get_nodes_block(node) == block) {
908 node = get_irn_n(node, i);
911 /* we might have unknowns as argument for the phi */
912 if (!arch_irn_consider_in_reg_alloc(cls, node))
916 /* check if node is in a register at end of pred */
917 pred_loc = workset_contains(pred_end_workset, node);
918 if (pred_loc != NULL) {
919 /* we might have to spill value on this path */
920 if (move_spills && !pred_loc->spilled && l->spilled) {
921 ir_node *insert_point
922 = be_get_end_of_block_insertion_point(pred);
923 insert_point = sched_prev(insert_point);
924 DB((dbg, DBG_SPILL, "Spill %+F after %+F\n", node,
926 be_add_spill(senv, node, insert_point);
929 /* node is not in register at the end of pred -> reload it */
930 DB((dbg, DBG_FIX, " reload %+F\n", node));
931 DB((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i));
932 be_add_reload_on_edge(senv, node, block, i, cls, 1);
938 static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *rcls)
941 ir_graph *irg = be_get_birg_irg(birg);
943 be_liveness_assure_sets(be_assure_liveness(birg));
946 /* construct control flow loop tree */
947 if (! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
948 construct_cf_backedges(irg);
950 stat_ev_tim_pop("belady_time_backedges");
954 stat_ev_tim_pop("belady_time_clear_links");
956 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
958 /* init belady env */
962 lv = be_get_birg_liveness(birg);
963 n_regs = cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
965 uses = be_begin_uses(irg, lv);
966 loop_ana = be_new_loop_pressure(birg, cls);
967 senv = be_new_spill_env(birg);
968 blocklist = be_get_cfgpostorder(irg);
969 stat_ev_tim_pop("belady_time_init");
972 /* walk blocks in reverse postorder */
973 for (i = ARR_LEN(blocklist) - 1; i >= 0; --i) {
974 process_block(blocklist[i]);
976 DEL_ARR_F(blocklist);
977 stat_ev_tim_pop("belady_time_belady");
980 /* belady was block-local, fix the global flow by adding reloads on the
982 irg_block_walk_graph(irg, fix_block_borders, NULL, NULL);
983 stat_ev_tim_pop("belady_time_fix_borders");
985 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
987 /* Insert spill/reload nodes into the graph and fix usages */
988 be_insert_spills_reloads(senv);
991 be_delete_spill_env(senv);
993 be_free_loop_pressure(loop_ana);
994 obstack_free(&obst, NULL);
997 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);
998 void be_init_spillbelady(void)
1000 static be_spiller_t belady_spiller = {
1003 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
1004 lc_opt_entry_t *belady_group = lc_opt_get_grp(be_grp, "belady");
1005 lc_opt_add_table(belady_group, options);
1007 be_register_spiller("belady", &belady_spiller);
1008 FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");