2 * Copyright (C) 1995-2007 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 implementation of the spill/reload placement abstraction layer
23 * @author Daniel Grund, Sebastian Hack, Matthias Braun
36 #include "iredges_t.h"
37 #include "irbackedge_t.h"
47 #include "irnodeset.h"
52 #include "besched_t.h"
56 #include "bechordal_t.h"
57 #include "bejavacoal.h"
58 #include "bespilloptions.h"
59 #include "bestatevent.h"
60 #include "bessaconstr.h"
62 #include "beintlive_t.h"
65 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
67 #define REMAT_COST_INFINITE 1000
69 typedef struct reloader_t reloader_t;
72 ir_node *can_spill_after;
74 ir_node *rematted_node;
75 int remat_cost_delta; /** costs needed for rematerialization,
76 compared to placing a reload */
79 typedef struct spill_t spill_t;
82 ir_node *before; /**< spill has to be placed before this node (or earlier) */
86 typedef struct spill_info_t spill_info_t;
88 ir_node *to_spill; /**< the value that should get spilled */
89 reloader_t *reloaders; /**< list of places where the value should get
91 spill_t *spills; /**< list of latest places where spill must be
93 double spill_costs; /**< costs needed for spilling the value */
94 const arch_register_class_t *reload_cls; /** the register class in which the
95 reload should be placed */
99 const arch_env_t *arch_env;
103 int spill_cost; /**< the cost of a single spill node */
104 int reload_cost; /**< the cost of a reload node */
105 set *spills; /**< all spill_info_t's, which must be
107 ir_nodeset_t mem_phis; /**< set of all spilled phis. */
108 ir_exec_freq *exec_freq;
109 unsigned new_nodes_idx; /**< all old nodes idx is smaller than
112 #ifdef FIRM_STATISTICS
113 unsigned spill_count;
114 unsigned reload_count;
115 unsigned remat_count;
116 unsigned spilled_phi_count;
121 * Compare two spill infos.
123 static int cmp_spillinfo(const void *x, const void *y, size_t size)
125 const spill_info_t *xx = x;
126 const spill_info_t *yy = y;
129 return xx->to_spill != yy->to_spill;
133 * Returns spill info for a specific value (the value that is to be spilled)
135 static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value)
137 spill_info_t info, *res;
138 int hash = hash_irn(value);
140 info.to_spill = value;
141 res = set_find(env->spills, &info, sizeof(info), hash);
144 info.reloaders = NULL;
146 info.spill_costs = -1;
147 info.reload_cls = NULL;
148 res = set_insert(env->spills, &info, sizeof(info), hash);
154 spill_env_t *be_new_spill_env(be_irg_t *birg)
156 const arch_env_t *arch_env = birg->main_env->arch_env;
158 spill_env_t *env = xmalloc(sizeof(env[0]));
159 env->spills = new_set(cmp_spillinfo, 1024);
160 env->irg = be_get_birg_irg(birg);
162 env->arch_env = arch_env;
163 ir_nodeset_init(&env->mem_phis);
164 env->spill_cost = arch_env->isa->spill_cost;
165 env->reload_cost = arch_env->isa->reload_cost;
166 env->exec_freq = be_get_birg_exec_freq(birg);
167 obstack_init(&env->obst);
169 #ifdef FIRM_STATISTICS
170 env->spill_count = 0;
171 env->reload_count = 0;
172 env->remat_count = 0;
173 env->spilled_phi_count = 0;
179 void be_delete_spill_env(spill_env_t *env)
181 del_set(env->spills);
182 ir_nodeset_destroy(&env->mem_phis);
183 obstack_free(&env->obst, NULL);
189 * | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___
190 * | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
191 * | __/| | (_| | (_| __/ | _ < __/ | (_) | (_| | (_| \__ \
192 * |_| |_|\__,_|\___\___| |_| \_\___|_|\___/ \__,_|\__,_|___/
196 void be_add_spill(spill_env_t *env, ir_node *to_spill, ir_node *before)
199 spill_info_t *spill_info = get_spillinfo(env, to_spill);
204 assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
205 DB((dbg, LEVEL_1, "Add spill of %+F before %+F\n", to_spill, before));
207 /* spills that are dominated by others are not needed */
209 s = spill_info->spills;
210 for( ; s != NULL; s = s->next) {
211 /* no need to add this spill if it is dominated by another */
212 if(value_dominates(s->before, before)) {
213 DB((dbg, LEVEL_1, "...dominated by %+F, not added\n", s->before));
216 /* remove spills that we dominate */
217 if(value_dominates(before, s->before)) {
218 DB((dbg, LEVEL_1, "...remove old spill at %+F\n", s->before));
220 last->next = s->next;
222 spill_info->spills = s->next;
229 spill = obstack_alloc(&env->obst, sizeof(spill[0]));
230 spill->before = before;
231 spill->next = spill_info->spills;
234 spill_info->spills = spill;
238 void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before,
239 ir_node *rematted_node)
241 spill_info_t *spill_info;
242 reloader_t *reloader;
244 spill_info = get_spillinfo(env, to_spill);
246 /* add the remat information */
247 reloader = obstack_alloc(&env->obst, sizeof(reloader[0]));
248 reloader->next = spill_info->reloaders;
249 reloader->reloader = before;
250 reloader->rematted_node = rematted_node;
251 reloader->remat_cost_delta = 0; /* We will never have a cost win over a
252 reload since we're not even allowed to
255 spill_info->reloaders = reloader;
257 DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n",
261 void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before,
262 ir_node *can_spill_after, const arch_register_class_t *reload_cls,
268 assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
270 info = get_spillinfo(env, to_spill);
272 if (is_Phi(to_spill)) {
275 /* create spillinfos for the phi arguments */
276 for (i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
277 ir_node *arg = get_irn_n(to_spill, i);
278 get_spillinfo(env, arg);
282 assert(!is_Proj(before) && !be_is_Keep(before));
284 /* put reload into list */
285 rel = obstack_alloc(&env->obst, sizeof(rel[0]));
286 rel->next = info->reloaders;
287 rel->reloader = before;
288 rel->rematted_node = NULL;
289 rel->can_spill_after = can_spill_after;
290 rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE;
292 info->reloaders = rel;
293 assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
294 info->reload_cls = reload_cls;
296 DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
297 to_spill, before, allow_remat ? "" : " not"));
300 void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
301 const arch_register_class_t *reload_cls, int allow_remat)
303 be_add_reload2(senv, to_spill, before, to_spill, reload_cls, allow_remat);
307 ir_node *be_get_end_of_block_insertion_point(const ir_node *block)
309 ir_node *last = sched_last(block);
311 /* we might have keeps behind the jump... */
312 while(be_is_Keep(last)) {
313 last = sched_prev(last);
314 assert(!sched_is_end(last));
317 assert(is_cfop(last));
319 /* add the reload before the (cond-)jump */
323 static ir_node *skip_keeps_phis(ir_node *node)
325 node = sched_next(node);
326 while(is_Phi(node) || be_is_Keep(node)) {
327 node = sched_next(node);
333 * Returns the point at which you can insert a node that should be executed
334 * before block @p block when coming from pred @p pos.
336 static ir_node *get_block_insertion_point(ir_node *block, int pos)
340 /* simply add the reload to the beginning of the block if we only have 1
341 * predecessor. We don't need to check for phis as there can't be any in a
342 * block with only 1 pred. */
343 if(get_Block_n_cfgpreds(block) == 1) {
344 assert(!is_Phi(sched_first(block)));
345 return sched_first(block);
348 /* We have to reload the value in pred-block */
349 predblock = get_Block_cfgpred_block(block, pos);
350 return be_get_end_of_block_insertion_point(predblock);
353 void be_add_reload_at_end(spill_env_t *env, ir_node *to_spill,
354 const ir_node *block,
355 const arch_register_class_t *reload_cls,
358 ir_node *before = be_get_end_of_block_insertion_point(block);
359 be_add_reload(env, to_spill, before, reload_cls, allow_remat);
362 void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block,
363 int pos, const arch_register_class_t *reload_cls,
366 ir_node *before = get_block_insertion_point(block, pos);
367 be_add_reload(env, to_spill, before, reload_cls, allow_remat);
370 void be_spill_phi(spill_env_t *env, ir_node *node)
376 assert(is_Phi(node));
378 ir_nodeset_insert(&env->mem_phis, node);
380 /* create spills for the phi arguments */
381 block = get_nodes_block(node);
382 spill = get_spillinfo(env, node);
383 for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
384 ir_node *arg = get_irn_n(node, i);
386 //get_spillinfo(env, arg);
388 /* some backends have virtual noreg/unknown nodes that are not scheduled
389 * and simply always available. */
390 if(!sched_is_scheduled(arg)) {
391 ir_node *pred_block = get_Block_cfgpred_block(block, i);
392 insert = be_get_end_of_block_insertion_point(pred_block);
394 insert = skip_keeps_phis(arg);
397 be_add_spill(env, arg, insert);
403 * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___
404 * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __|
405 * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \
406 * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/
410 static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo);
415 * @param senv the spill environment
416 * @param irn the node that should be spilled
417 * @param ctx_irn an user of the spilled node
419 * @return a be_Spill node
421 static void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
423 ir_node *to_spill = spillinfo->to_spill;
426 /* determine_spill_costs must have been run before */
427 assert(spillinfo->spill_costs >= 0);
429 /* some backends have virtual noreg/unknown nodes that are not scheduled
430 * and simply always available. */
431 if(!sched_is_scheduled(to_spill)) {
432 /* override spillinfos or create a new one */
433 spillinfo->spills->spill = new_NoMem();
434 DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
438 DBG((dbg, LEVEL_1, "spilling %+F ... ", to_spill));
439 spill = spillinfo->spills;
440 for( ; spill != NULL; spill = spill->next) {
441 ir_node *block = get_block(spill->before);
442 ir_node *before = spill->before;
444 /* place all spills before the reloads (as we can't guarantee the
445 * same order as the be_add_spill and be_add_reload calls */
446 while(get_irn_idx(sched_prev(before)) > env->new_nodes_idx) {
447 before = sched_prev(before);
450 spill->spill = be_spill(env->arch_env, block, to_spill);
451 sched_add_before(before, spill->spill);
452 DB((dbg, LEVEL_1, "\t%+F before %+F\n", spill->spill, before));
453 #ifdef FIRM_STATISTICS
457 DBG((dbg, LEVEL_1, "\n"));
460 static void spill_node(spill_env_t *env, spill_info_t *spillinfo);
463 * If the first usage of a Phi result would be out of memory
464 * there is no sense in allocating a register for it.
465 * Thus we spill it and all its operands to the same spill slot.
466 * Therefore the phi/dataB becomes a phi/Memory
468 * @param senv the spill environment
469 * @param phi the Phi node that should be spilled
470 * @param ctx_irn an user of the spilled node
472 static void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
474 ir_graph *irg = env->irg;
475 ir_node *phi = spillinfo->to_spill;
476 ir_node *block = get_nodes_block(phi);
484 assert(!get_opt_cse());
485 DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
487 /* build a new PhiM */
488 arity = get_irn_arity(phi);
489 ins = alloca(sizeof(ir_node*) * arity);
490 unknown = new_r_Unknown(irg, mode_M);
491 for(i = 0; i < arity; ++i) {
495 /* override or replace spills list... */
496 spill = obstack_alloc(&env->obst, sizeof(spill[0]));
497 spill->before = skip_keeps_phis(phi);
498 spill->spill = new_r_Phi(irg, block, arity, ins, mode_M);
501 spillinfo->spills = spill;
502 #ifdef FIRM_STATISTICS
503 env->spilled_phi_count++;
506 for(i = 0; i < arity; ++i) {
507 ir_node *arg = get_irn_n(phi, i);
508 spill_info_t *arg_info = get_spillinfo(env, arg);
510 determine_spill_costs(env, arg_info);
511 spill_node(env, arg_info);
513 set_irn_n(spill->spill, i, arg_info->spills->spill);
515 DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi,
522 * @param senv the spill environment
523 * @param to_spill the node that should be spilled
525 static void spill_node(spill_env_t *env, spill_info_t *spillinfo)
529 /* node is already spilled */
530 if(spillinfo->spills != NULL && spillinfo->spills->spill != NULL)
533 to_spill = spillinfo->to_spill;
535 if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
536 spill_phi(env, spillinfo);
538 spill_irn(env, spillinfo);
545 * | _ \ ___ _ __ ___ __ _| |_ ___ _ __(_) __ _| (_)_______
546 * | |_) / _ \ '_ ` _ \ / _` | __/ _ \ '__| |/ _` | | |_ / _ \
547 * | _ < __/ | | | | | (_| | || __/ | | | (_| | | |/ / __/
548 * |_| \_\___|_| |_| |_|\__,_|\__\___|_| |_|\__,_|_|_/___\___|
553 * Tests whether value @p arg is available before node @p reloader
554 * @returns 1 if value is available, 0 otherwise
556 static int is_value_available(spill_env_t *env, const ir_node *arg,
557 const ir_node *reloader)
559 if(is_Unknown(arg) || arg == new_NoMem())
565 if(arg == get_irg_frame(env->irg))
568 /* hack for now (happens when command should be inserted at end of block) */
569 if(is_Block(reloader)) {
574 * Ignore registers are always available
576 if(arch_irn_is(env->arch_env, arg, ignore)) {
580 /* the following test does not work while spilling,
581 * because the liveness info is not adapted yet to the effects of the
582 * additional spills/reloads.
585 /* we want to remat before the insn reloader
586 * thus an arguments is alive if
587 * - it interferes with the reloaders result
588 * - or it is (last-) used by reloader itself
590 if (values_interfere(env->birg->lv, reloader, arg)) {
594 arity = get_irn_arity(reloader);
595 for (i = 0; i < arity; ++i) {
596 ir_node *rel_arg = get_irn_n(reloader, i);
606 * Checks whether the node can principally be rematerialized
608 static int is_remat_node(spill_env_t *env, const ir_node *node)
610 const arch_env_t *arch_env = env->arch_env;
612 assert(!be_is_Spill(node));
614 if(arch_irn_is(arch_env, node, rematerializable))
621 * Check if a node is rematerializable. This tests for the following conditions:
623 * - The node itself is rematerializable
624 * - All arguments of the node are available or also rematerialisable
625 * - The costs for the rematerialisation operation is less or equal a limit
627 * Returns the costs needed for rematerialisation or something
628 * >= REMAT_COST_INFINITE if remat is not possible.
630 static int check_remat_conditions_costs(spill_env_t *env,
631 const ir_node *spilled, const ir_node *reloader, int parentcosts)
637 if(!is_remat_node(env, spilled))
638 return REMAT_COST_INFINITE;
640 if(be_is_Reload(spilled)) {
643 costs += arch_get_op_estimated_cost(env->arch_env, spilled);
645 if(parentcosts + costs >= env->reload_cost + env->spill_cost) {
646 return REMAT_COST_INFINITE;
648 if(arch_irn_is(env->arch_env, spilled, modify_flags)) {
649 return REMAT_COST_INFINITE;
653 for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
654 ir_node *arg = get_irn_n(spilled, i);
656 if(is_value_available(env, arg, reloader))
659 /* we have to rematerialize the argument as well */
661 /* we only support rematerializing 1 argument at the moment,
662 * so that we don't have to care about register pressure
664 return REMAT_COST_INFINITE;
668 costs += check_remat_conditions_costs(env, arg, reloader,
669 parentcosts + costs);
670 if(parentcosts + costs >= env->reload_cost + env->spill_cost)
671 return REMAT_COST_INFINITE;
678 * Re-materialize a node.
680 * @param senv the spill environment
681 * @param spilled the node that was spilled
682 * @param reloader a irn that requires a reload
684 static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader)
691 if(is_Block(reloader)) {
694 bl = get_nodes_block(reloader);
697 ins = alloca(get_irn_arity(spilled) * sizeof(ins[0]));
698 for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
699 ir_node *arg = get_irn_n(spilled, i);
701 if(is_value_available(env, arg, reloader)) {
704 ins[i] = do_remat(env, arg, reloader);
705 #ifdef FIRM_STATISTICS
706 /* don't count the recursive call as remat */
712 /* create a copy of the node */
713 res = new_ir_node(get_irn_dbg_info(spilled), env->irg, bl,
714 get_irn_op(spilled), get_irn_mode(spilled),
715 get_irn_arity(spilled), ins);
716 copy_node_attr(spilled, res);
717 new_backedge_info(res);
719 DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
721 if (! is_Proj(res)) {
722 /* insert in schedule */
724 sched_add_before(reloader, res);
725 #ifdef FIRM_STATISTICS
733 double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
735 ir_node *block = get_nodes_block(before);
736 double freq = get_block_execfreq(env->exec_freq, block);
739 return env->spill_cost * freq;
742 unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
743 const ir_node *before)
746 /* is the node rematerializable? */
747 unsigned costs = check_remat_conditions_costs(env, to_spill, before, 0);
748 if(costs < (unsigned) env->reload_cost)
752 return env->reload_cost;
755 double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
757 ir_node *block = get_nodes_block(before);
758 double freq = get_block_execfreq(env->exec_freq, block);
761 /* is the node rematerializable? */
762 int costs = check_remat_conditions_costs(env, to_spill, before, 0);
763 if(costs < env->reload_cost)
767 return env->reload_cost * freq;
770 int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat,
771 const ir_node *before)
773 return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE;
776 double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
777 ir_node *block, int pos)
779 ir_node *before = get_block_insertion_point(block, pos);
780 return be_get_reload_costs(env, to_spill, before);
785 * |_ _|_ __ ___ ___ _ __| |_ | _ \ ___| | ___ __ _ __| |___
786 * | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ |/ _ \ / _` |/ _` / __|
787 * | || | | \__ \ __/ | | |_ | _ < __/ | (_) | (_| | (_| \__ \
788 * |___|_| |_|___/\___|_| \__| |_| \_\___|_|\___/ \__,_|\__,_|___/
793 * analyzes how to best spill a node and determine costs for that
795 static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo)
797 ir_node *to_spill = spillinfo->to_spill;
798 ir_node *spill_block;
800 double spill_execfreq;
802 /* already calculated? */
803 if(spillinfo->spill_costs >= 0)
806 assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
807 assert(!be_is_Reload(to_spill));
809 /* some backends have virtual noreg/unknown nodes that are not scheduled
810 * and simply always available.
811 * TODO: this is kinda hairy, the NoMem is correct for an Unknown as Phi
812 * predecessor (of a PhiM) but this test might match other things too...
814 if(!sched_is_scheduled(to_spill)) {
815 /* override spillinfos or create a new one */
816 spill_t *spill = obstack_alloc(&env->obst, sizeof(spill[0]));
817 spill->before = NULL;
819 spill->spill = new_NoMem();
821 spillinfo->spills = spill;
822 spillinfo->spill_costs = 0;
824 DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
828 spill_block = get_nodes_block(to_spill);
829 spill_execfreq = get_block_execfreq(env->exec_freq, spill_block);
831 if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
832 /* TODO calculate correct costs...
833 * (though we can't remat this node anyway so no big problem) */
834 spillinfo->spill_costs = env->spill_cost * spill_execfreq;
838 if(spillinfo->spills != NULL) {
840 double spills_execfreq;
842 /* calculate sum of executaion frequencies of individual spills */
844 s = spillinfo->spills;
845 for( ; s != NULL; s = s->next) {
846 ir_node *spill_block = s->before;
849 if(!is_Block(spill_block)) {
850 spill_block = get_nodes_block(spill_block);
852 freq = get_block_execfreq(env->exec_freq, spill_block);
854 spills_execfreq += freq;
857 DB((dbg, LEVEL_1, "%+F: latespillcosts %f after def: %f\n", to_spill,
858 spills_execfreq * env->spill_cost,
859 spill_execfreq * env->spill_cost));
861 /* multi-/latespill is advantageous -> return*/
862 if(spills_execfreq < spill_execfreq) {
863 DB((dbg, LEVEL_1, "use latespills for %+F\n", to_spill));
864 spillinfo->spill_costs = spills_execfreq * env->spill_cost;
869 /* override spillinfos or create a new one */
870 spill = obstack_alloc(&env->obst, sizeof(spill[0]));
871 spill->before = skip_keeps_phis(to_spill);
875 spillinfo->spills = spill;
876 spillinfo->spill_costs = spill_execfreq * env->spill_cost;
877 DB((dbg, LEVEL_1, "spill %+F after definition\n", to_spill));
880 void be_insert_spills_reloads(spill_env_t *env)
882 ir_graph *irg = env->irg;
883 const arch_env_t *arch_env = env->arch_env;
884 const ir_exec_freq *exec_freq = env->exec_freq;
886 ir_nodeset_iterator_t iter;
889 env->new_nodes_idx = get_irg_last_idx(irg);
891 /* create all phi-ms first, this is needed so, that phis, hanging on
892 spilled phis work correctly */
893 foreach_ir_nodeset(&env->mem_phis, node, iter) {
894 spill_info_t *info = get_spillinfo(env, node);
895 spill_node(env, info);
898 /* process each spilled node */
899 for (si = set_first(env->spills); si; si = set_next(env->spills)) {
901 ir_node *to_spill = si->to_spill;
902 ir_mode *mode = get_irn_mode(to_spill);
903 ir_node **copies = NEW_ARR_F(ir_node*, 0);
904 double all_remat_costs = 0; /** costs when we would remat all nodes */
907 DBG((dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", to_spill));
909 determine_spill_costs(env, si);
911 /* determine possibility of rematerialisations */
913 /* calculate cost savings for each indivial value when it would
914 be rematted instead of reloaded */
915 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
918 int remat_cost_delta;
920 ir_node *reloader = rld->reloader;
922 if(rld->rematted_node != NULL) {
923 DBG((dbg, LEVEL_2, "\tforced remat %+F before %+F\n",
924 rld->rematted_node, reloader));
927 if(rld->remat_cost_delta >= REMAT_COST_INFINITE) {
928 DBG((dbg, LEVEL_2, "\treload before %+F is forbidden\n",
930 all_remat_costs = REMAT_COST_INFINITE;
934 remat_cost = check_remat_conditions_costs(env, to_spill,
936 if(remat_cost >= REMAT_COST_INFINITE) {
937 DBG((dbg, LEVEL_2, "\tremat before %+F not possible\n",
939 rld->remat_cost_delta = REMAT_COST_INFINITE;
940 all_remat_costs = REMAT_COST_INFINITE;
944 remat_cost_delta = remat_cost - env->reload_cost;
945 rld->remat_cost_delta = remat_cost_delta;
946 block = is_Block(reloader) ? reloader : get_nodes_block(reloader);
947 freq = get_block_execfreq(exec_freq, block);
948 all_remat_costs += remat_cost_delta * freq;
949 DBG((dbg, LEVEL_2, "\tremat costs delta before %+F: "
950 "%d (rel %f)\n", reloader, remat_cost_delta,
951 remat_cost_delta * freq));
953 if(all_remat_costs < REMAT_COST_INFINITE) {
954 /* we don't need the costs for the spill if we can remat
956 all_remat_costs -= si->spill_costs;
958 DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
959 env->spill_cost, si->spill_costs));
962 if(all_remat_costs < 0) {
963 DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
969 /* go through all reloads for this spill */
970 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
971 ir_node *copy; /* a reload is a "copy" of the original value */
973 if (rld->rematted_node != NULL) {
974 copy = rld->rematted_node;
975 sched_add_before(rld->reloader, copy);
976 } else if (be_do_remats &&
977 (force_remat || rld->remat_cost_delta < 0)) {
978 copy = do_remat(env, to_spill, rld->reloader);
980 /* make sure we have a spill */
983 /* create a reload, use the first spill for now SSA
984 * reconstruction for memory comes below */
985 assert(si->spills != NULL);
986 copy = be_reload(arch_env, si->reload_cls, rld->reloader, mode,
988 #ifdef FIRM_STATISTICS
993 DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
994 copy, to_spill, rld->reloader));
995 ARR_APP1(ir_node*, copies, copy);
998 /* if we had any reloads or remats, then we need to reconstruct the
999 * SSA form for the spilled value */
1000 if (ARR_LEN(copies) > 0) {
1001 be_ssa_construction_env_t senv;
1002 /* be_lv_t *lv = be_get_birg_liveness(env->birg); */
1004 be_ssa_construction_init(&senv, env->birg);
1005 be_ssa_construction_add_copy(&senv, to_spill);
1006 be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies));
1007 be_ssa_construction_fix_users(&senv, to_spill);
1010 /* no need to enable this as long as we invalidate liveness
1011 after this function... */
1012 be_ssa_construction_update_liveness_phis(&senv);
1013 be_liveness_update(to_spill);
1014 len = ARR_LEN(copies);
1015 for(i = 0; i < len; ++i) {
1016 be_liveness_update(lv, copies[i]);
1019 be_ssa_construction_destroy(&senv);
1021 /* need to reconstruct SSA form if we had multiple spills */
1022 if (si->spills != NULL && si->spills->next != NULL) {
1024 int spill_count = 0;
1026 be_ssa_construction_env_t senv;
1028 be_ssa_construction_init(&senv, env->birg);
1030 for( ; spill != NULL; spill = spill->next) {
1031 /* maybe we rematerialized the value and need no spill */
1032 if(spill->spill == NULL)
1034 be_ssa_construction_add_copy(&senv, spill->spill);
1037 if(spill_count > 1) {
1038 /* all reloads are attached to the first spill, fix them now */
1039 be_ssa_construction_fix_users(&senv, si->spills->spill);
1042 be_ssa_construction_destroy(&senv);
1046 si->reloaders = NULL;
1049 stat_ev_dbl("spill_spills", env->spill_count);
1050 stat_ev_dbl("spill_reloads", env->reload_count);
1051 stat_ev_dbl("spill_remats", env->remat_count);
1052 stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count);
1054 /* Matze: In theory be_ssa_construction should take care of the liveness...
1055 * try to disable this again in the future */
1056 be_liveness_invalidate(env->birg->lv);
1058 be_remove_dead_nodes_from_schedule(env->birg);
1061 void be_init_spill(void)
1063 FIRM_DBG_REGISTER(dbg, "firm.be.spill");
1066 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);