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 implementation of the spill/reload placement abstraction layer
23 * @author Daniel Grund, Sebastian Hack, Matthias Braun
35 #include "iredges_t.h"
36 #include "irbackedge_t.h"
46 #include "irnodeset.h"
53 #include "bespillutil.h"
56 #include "bechordal_t.h"
57 #include "bestatevent.h"
58 #include "bessaconstr.h"
61 #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 *after; /**< spill has to be placed after 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;
102 int spill_cost; /**< the cost of a single spill node */
103 int reload_cost; /**< the cost of a reload node */
104 set *spills; /**< all spill_info_t's, which must be
106 ir_nodeset_t mem_phis; /**< set of all spilled phis. */
107 ir_exec_freq *exec_freq;
109 #ifdef FIRM_STATISTICS
110 unsigned spill_count;
111 unsigned reload_count;
112 unsigned remat_count;
113 unsigned spilled_phi_count;
118 * Compare two spill infos.
120 static int cmp_spillinfo(const void *x, const void *y, size_t size)
122 const spill_info_t *xx = (const spill_info_t*)x;
123 const spill_info_t *yy = (const spill_info_t*)y;
126 return xx->to_spill != yy->to_spill;
130 * Returns spill info for a specific value (the value that is to be spilled)
132 static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value)
134 spill_info_t info, *res;
135 int hash = hash_irn(value);
137 info.to_spill = value;
138 res = (spill_info_t*)set_find(env->spills, &info, sizeof(info), hash);
141 info.reloaders = NULL;
143 info.spill_costs = -1;
144 info.reload_cls = NULL;
145 res = (spill_info_t*)set_insert(env->spills, &info, sizeof(info), hash);
151 spill_env_t *be_new_spill_env(ir_graph *irg)
153 const arch_env_t *arch_env = be_get_irg_arch_env(irg);
155 spill_env_t *env = XMALLOC(spill_env_t);
156 env->spills = new_set(cmp_spillinfo, 1024);
158 env->arch_env = arch_env;
159 ir_nodeset_init(&env->mem_phis);
160 env->spill_cost = arch_env->spill_cost;
161 env->reload_cost = arch_env->reload_cost;
162 env->exec_freq = be_get_irg_exec_freq(irg);
163 obstack_init(&env->obst);
165 #ifdef FIRM_STATISTICS
166 env->spill_count = 0;
167 env->reload_count = 0;
168 env->remat_count = 0;
169 env->spilled_phi_count = 0;
175 void be_delete_spill_env(spill_env_t *env)
177 del_set(env->spills);
178 ir_nodeset_destroy(&env->mem_phis);
179 obstack_free(&env->obst, NULL);
185 * | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___
186 * | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
187 * | __/| | (_| | (_| __/ | _ < __/ | (_) | (_| | (_| \__ \
188 * |_| |_|\__,_|\___\___| |_| \_\___|_|\___/ \__,_|\__,_|___/
192 void be_add_spill(spill_env_t *env, ir_node *to_spill, ir_node *after)
194 spill_info_t *spill_info = get_spillinfo(env, to_spill);
199 assert(!arch_irn_is(skip_Proj_const(to_spill), dont_spill));
200 DB((dbg, LEVEL_1, "Add spill of %+F after %+F\n", to_spill, after));
202 /* Just for safety make sure that we do not insert the spill in front of a phi */
203 assert(!is_Phi(sched_next(after)));
205 /* spills that are dominated by others are not needed */
207 s = spill_info->spills;
208 for ( ; s != NULL; s = s->next) {
209 /* no need to add this spill if it is dominated by another */
210 if (value_dominates(s->after, after)) {
211 DB((dbg, LEVEL_1, "...dominated by %+F, not added\n", s->after));
214 /* remove spills that we dominate */
215 if (value_dominates(after, s->after)) {
216 DB((dbg, LEVEL_1, "...remove old spill at %+F\n", s->after));
218 last->next = s->next;
220 spill_info->spills = s->next;
227 spill = OALLOC(&env->obst, spill_t);
228 spill->after = after;
229 spill->next = spill_info->spills;
232 spill_info->spills = spill;
235 void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before,
236 ir_node *can_spill_after, const arch_register_class_t *reload_cls,
242 assert(!arch_irn_is(skip_Proj_const(to_spill), dont_spill));
244 info = get_spillinfo(env, to_spill);
246 if (is_Phi(to_spill)) {
249 /* create spillinfos for the phi arguments */
250 for (i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
251 ir_node *arg = get_irn_n(to_spill, i);
252 get_spillinfo(env, arg);
256 assert(!is_Proj(before) && !be_is_Keep(before));
258 /* adjust before point to not be in the epilog */
260 ir_node *before_prev = sched_prev(before);
261 if (! (arch_irn_get_flags(before_prev) & arch_irn_flags_epilog))
263 before = sched_prev(before);
266 /* put reload into list */
267 rel = OALLOC(&env->obst, reloader_t);
268 rel->next = info->reloaders;
269 rel->reloader = before;
270 rel->rematted_node = NULL;
271 rel->can_spill_after = can_spill_after;
272 rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE;
274 info->reloaders = rel;
275 assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
276 info->reload_cls = reload_cls;
278 DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
279 to_spill, before, allow_remat ? "" : " not"));
282 void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
283 const arch_register_class_t *reload_cls, int allow_remat)
285 be_add_reload2(senv, to_spill, before, to_spill, reload_cls, allow_remat);
289 ir_node *be_get_end_of_block_insertion_point(const ir_node *block)
291 ir_node *last = sched_last(block);
293 /* we might have keeps behind the jump... */
294 while (be_is_Keep(last)) {
295 last = sched_prev(last);
296 assert(!sched_is_end(last));
299 assert(is_cfop(last));
301 /* add the reload before the (cond-)jump */
306 * determine final spill position: it should be after all phis, keep nodes
307 * and behind nodes marked as prolog
309 static ir_node *determine_spill_point(ir_node *node)
311 node = skip_Proj(node);
313 ir_node *next = sched_next(node);
314 if (!is_Phi(next) && !be_is_Keep(next) && !be_is_CopyKeep(next)
315 && !(arch_irn_get_flags(next) & arch_irn_flags_prolog))
323 * Returns the point at which you can insert a node that should be executed
324 * before block @p block when coming from pred @p pos.
326 static ir_node *get_block_insertion_point(ir_node *block, int pos)
330 /* simply add the reload to the beginning of the block if we only have 1
331 * predecessor. We don't need to check for phis as there can't be any in a
332 * block with only 1 pred. */
333 if (get_Block_n_cfgpreds(block) == 1) {
334 assert(!is_Phi(sched_first(block)));
335 return sched_first(block);
338 /* We have to reload the value in pred-block */
339 predblock = get_Block_cfgpred_block(block, pos);
340 return be_get_end_of_block_insertion_point(predblock);
343 void be_add_reload_at_end(spill_env_t *env, ir_node *to_spill,
344 const ir_node *block,
345 const arch_register_class_t *reload_cls,
348 ir_node *before = be_get_end_of_block_insertion_point(block);
349 be_add_reload(env, to_spill, before, reload_cls, allow_remat);
352 void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block,
353 int pos, const arch_register_class_t *reload_cls,
356 ir_node *before = get_block_insertion_point(block, pos);
357 be_add_reload(env, to_spill, before, reload_cls, allow_remat);
360 void be_spill_phi(spill_env_t *env, ir_node *node)
365 assert(is_Phi(node));
367 ir_nodeset_insert(&env->mem_phis, node);
369 /* create spills for the phi arguments */
370 block = get_nodes_block(node);
371 for (i = 0, arity = get_irn_arity(node); i < arity; ++i) {
372 ir_node *arg = get_irn_n(node, i);
375 /* some backends have virtual noreg/unknown nodes that are not scheduled
376 * and simply always available. */
377 if (!sched_is_scheduled(arg)) {
378 ir_node *pred_block = get_Block_cfgpred_block(block, i);
379 insert = be_get_end_of_block_insertion_point(pred_block);
380 insert = sched_prev(insert);
382 insert = determine_spill_point(arg);
385 be_add_spill(env, arg, insert);
391 * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___
392 * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __|
393 * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \
394 * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/
398 static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo);
403 * @param senv the spill environment
404 * @param irn the node that should be spilled
405 * @param ctx_irn an user of the spilled node
407 * @return a be_Spill node
409 static void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
411 ir_node *to_spill = spillinfo->to_spill;
412 const ir_node *insn = skip_Proj_const(to_spill);
415 /* determine_spill_costs must have been run before */
416 assert(spillinfo->spill_costs >= 0);
418 /* some backends have virtual noreg/unknown nodes that are not scheduled
419 * and simply always available. */
420 if (!sched_is_scheduled(insn)) {
421 /* override spillinfos or create a new one */
422 ir_graph *irg = get_irn_irg(to_spill);
423 spillinfo->spills->spill = new_r_NoMem(irg);
424 DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
428 DBG((dbg, LEVEL_1, "spilling %+F ... \n", to_spill));
429 spill = spillinfo->spills;
430 for ( ; spill != NULL; spill = spill->next) {
431 ir_node *after = spill->after;
432 ir_node *block = get_block(after);
434 after = determine_spill_point(after);
436 spill->spill = be_spill(block, to_spill);
437 sched_add_after(skip_Proj(after), spill->spill);
438 DB((dbg, LEVEL_1, "\t%+F after %+F\n", spill->spill, after));
439 #ifdef FIRM_STATISTICS
443 DBG((dbg, LEVEL_1, "\n"));
446 static void spill_node(spill_env_t *env, spill_info_t *spillinfo);
449 * If the first usage of a Phi result would be out of memory
450 * there is no sense in allocating a register for it.
451 * Thus we spill it and all its operands to the same spill slot.
452 * Therefore the phi/dataB becomes a phi/Memory
454 * @param senv the spill environment
455 * @param phi the Phi node that should be spilled
456 * @param ctx_irn an user of the spilled node
458 static void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
460 ir_graph *irg = env->irg;
461 ir_node *phi = spillinfo->to_spill;
462 ir_node *block = get_nodes_block(phi);
470 assert(!get_opt_cse());
471 DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
473 /* build a new PhiM */
474 arity = get_irn_arity(phi);
475 ins = ALLOCAN(ir_node*, arity);
476 unknown = new_r_Unknown(irg, mode_M);
477 for (i = 0; i < arity; ++i) {
481 /* override or replace spills list... */
482 spill = OALLOC(&env->obst, spill_t);
483 spill->after = determine_spill_point(phi);
484 spill->spill = be_new_Phi(block, arity, ins, mode_M, NULL);
486 sched_add_after(block, spill->spill);
488 spillinfo->spills = spill;
489 #ifdef FIRM_STATISTICS
490 env->spilled_phi_count++;
493 for (i = 0; i < arity; ++i) {
494 ir_node *arg = get_irn_n(phi, i);
495 spill_info_t *arg_info = get_spillinfo(env, arg);
497 determine_spill_costs(env, arg_info);
498 spill_node(env, arg_info);
500 set_irn_n(spill->spill, i, arg_info->spills->spill);
502 DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi,
509 * @param senv the spill environment
510 * @param to_spill the node that should be spilled
512 static void spill_node(spill_env_t *env, spill_info_t *spillinfo)
516 /* node is already spilled */
517 if (spillinfo->spills != NULL && spillinfo->spills->spill != NULL)
520 to_spill = spillinfo->to_spill;
522 if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
523 spill_phi(env, spillinfo);
525 spill_irn(env, spillinfo);
532 * | _ \ ___ _ __ ___ __ _| |_ ___ _ __(_) __ _| (_)_______
533 * | |_) / _ \ '_ ` _ \ / _` | __/ _ \ '__| |/ _` | | |_ / _ \
534 * | _ < __/ | | | | | (_| | || __/ | | | (_| | | |/ / __/
535 * |_| \_\___|_| |_| |_|\__,_|\__\___|_| |_|\__,_|_|_/___\___|
540 * Tests whether value @p arg is available before node @p reloader
541 * @returns 1 if value is available, 0 otherwise
543 static int is_value_available(spill_env_t *env, const ir_node *arg,
544 const ir_node *reloader)
546 if (is_Unknown(arg) || is_NoMem(arg))
549 if (be_is_Spill(skip_Proj_const(arg)))
552 if (arg == get_irg_frame(env->irg))
557 if (get_irn_mode(arg) == mode_T)
561 * Ignore registers are always available
563 if (arch_irn_is_ignore(arg))
570 * Check if a node is rematerializable. This tests for the following conditions:
572 * - The node itself is rematerializable
573 * - All arguments of the node are available or also rematerialisable
574 * - The costs for the rematerialisation operation is less or equal a limit
576 * Returns the costs needed for rematerialisation or something
577 * >= REMAT_COST_INFINITE if remat is not possible.
579 static int check_remat_conditions_costs(spill_env_t *env,
580 const ir_node *spilled, const ir_node *reloader, int parentcosts)
585 const ir_node *insn = skip_Proj_const(spilled);
587 assert(!be_is_Spill(insn));
588 if (!arch_irn_is(insn, rematerializable))
589 return REMAT_COST_INFINITE;
591 if (be_is_Reload(insn)) {
594 costs += arch_get_op_estimated_cost(insn);
596 if (parentcosts + costs >= env->reload_cost + env->spill_cost) {
597 return REMAT_COST_INFINITE;
599 /* never rematerialize a node which modifies the flags.
600 * (would be better to test wether the flags are actually live at point
603 if (arch_irn_is(insn, modify_flags)) {
604 return REMAT_COST_INFINITE;
608 for (i = 0, arity = get_irn_arity(insn); i < arity; ++i) {
609 ir_node *arg = get_irn_n(insn, i);
611 if (is_value_available(env, arg, reloader))
614 /* we have to rematerialize the argument as well */
617 /* we only support rematerializing 1 argument at the moment,
618 * as multiple arguments could increase register pressure */
619 return REMAT_COST_INFINITE;
622 costs += check_remat_conditions_costs(env, arg, reloader,
623 parentcosts + costs);
624 if (parentcosts + costs >= env->reload_cost + env->spill_cost)
625 return REMAT_COST_INFINITE;
632 * Re-materialize a node.
634 * @param senv the spill environment
635 * @param spilled the node that was spilled
636 * @param reloader a irn that requires a reload
638 static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader)
645 if (is_Block(reloader)) {
648 bl = get_nodes_block(reloader);
651 ins = ALLOCAN(ir_node*, get_irn_arity(spilled));
652 for (i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
653 ir_node *arg = get_irn_n(spilled, i);
655 if (is_value_available(env, arg, reloader)) {
658 ins[i] = do_remat(env, arg, reloader);
659 #ifdef FIRM_STATISTICS
660 /* don't count the recursive call as remat */
666 /* create a copy of the node */
667 res = new_ir_node(get_irn_dbg_info(spilled), env->irg, bl,
668 get_irn_op(spilled), get_irn_mode(spilled),
669 get_irn_arity(spilled), ins);
670 copy_node_attr(env->irg, spilled, res);
671 arch_env_mark_remat(env->arch_env, res);
673 DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
675 if (! is_Proj(res)) {
676 /* insert in schedule */
678 sched_add_before(reloader, res);
679 #ifdef FIRM_STATISTICS
687 double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
689 ir_node *block = get_nodes_block(before);
690 double freq = get_block_execfreq(env->exec_freq, block);
693 return env->spill_cost * freq;
696 unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
697 const ir_node *before)
700 /* is the node rematerializable? */
701 unsigned costs = check_remat_conditions_costs(env, to_spill, before, 0);
702 if (costs < (unsigned) env->reload_cost)
706 return env->reload_cost;
709 double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
711 ir_node *block = get_nodes_block(before);
712 double freq = get_block_execfreq(env->exec_freq, block);
715 /* is the node rematerializable? */
716 int costs = check_remat_conditions_costs(env, to_spill, before, 0);
717 if (costs < env->reload_cost)
721 return env->reload_cost * freq;
724 int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat,
725 const ir_node *before)
727 return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE;
730 double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
731 ir_node *block, int pos)
733 ir_node *before = get_block_insertion_point(block, pos);
734 return be_get_reload_costs(env, to_spill, before);
739 * |_ _|_ __ ___ ___ _ __| |_ | _ \ ___| | ___ __ _ __| |___
740 * | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ |/ _ \ / _` |/ _` / __|
741 * | || | | \__ \ __/ | | |_ | _ < __/ | (_) | (_| | (_| \__ \
742 * |___|_| |_|___/\___|_| \__| |_| \_\___|_|\___/ \__,_|\__,_|___/
747 * analyzes how to best spill a node and determine costs for that
749 static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo)
751 ir_node *to_spill = spillinfo->to_spill;
752 const ir_node *insn = skip_Proj_const(to_spill);
753 ir_node *spill_block;
755 double spill_execfreq;
757 /* already calculated? */
758 if (spillinfo->spill_costs >= 0)
761 assert(!arch_irn_is(insn, dont_spill));
762 assert(!be_is_Reload(insn));
764 /* some backends have virtual noreg/unknown nodes that are not scheduled
765 * and simply always available.
766 * TODO: this is kinda hairy, the NoMem is correct for an Unknown as Phi
767 * predecessor (of a PhiM) but this test might match other things too...
769 if (!sched_is_scheduled(insn)) {
770 ir_graph *irg = get_irn_irg(to_spill);
771 /* override spillinfos or create a new one */
772 spill_t *spill = OALLOC(&env->obst, spill_t);
775 spill->spill = new_r_NoMem(irg);
777 spillinfo->spills = spill;
778 spillinfo->spill_costs = 0;
780 DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
784 spill_block = get_nodes_block(insn);
785 spill_execfreq = get_block_execfreq(env->exec_freq, spill_block);
787 if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
788 /* TODO calculate correct costs...
789 * (though we can't remat this node anyway so no big problem) */
790 spillinfo->spill_costs = env->spill_cost * spill_execfreq;
794 if (spillinfo->spills != NULL) {
796 double spills_execfreq;
798 /* calculate sum of execution frequencies of individual spills */
800 s = spillinfo->spills;
801 for ( ; s != NULL; s = s->next) {
802 ir_node *spill_block = get_block(s->after);
803 double freq = get_block_execfreq(env->exec_freq, spill_block);
805 spills_execfreq += freq;
808 DB((dbg, LEVEL_1, "%+F: latespillcosts %f after def: %f\n", to_spill,
809 spills_execfreq * env->spill_cost,
810 spill_execfreq * env->spill_cost));
812 /* multi-/latespill is advantageous -> return*/
813 if (spills_execfreq < spill_execfreq) {
814 DB((dbg, LEVEL_1, "use latespills for %+F\n", to_spill));
815 spillinfo->spill_costs = spills_execfreq * env->spill_cost;
820 /* override spillinfos or create a new one */
821 spill = OALLOC(&env->obst, spill_t);
822 spill->after = determine_spill_point(to_spill);
826 spillinfo->spills = spill;
827 spillinfo->spill_costs = spill_execfreq * env->spill_cost;
828 DB((dbg, LEVEL_1, "spill %+F after definition\n", to_spill));
831 void make_spill_locations_dominate_irn(spill_env_t *env, ir_node *irn)
833 const spill_info_t *si = get_spillinfo(env, irn);
834 ir_node *start_block = get_irg_start_block(get_irn_irg(irn));
835 int n_blocks = get_Block_dom_max_subtree_pre_num(start_block);
836 bitset_t *reloads = bitset_alloca(n_blocks);
843 /* Fill the bitset with the dominance pre-order numbers
844 * of the blocks the reloads are located in. */
845 for (r = si->reloaders; r != NULL; r = r->next) {
846 ir_node *bl = get_nodes_block(r->reloader);
847 bitset_set(reloads, get_Block_dom_tree_pre_num(bl));
850 /* Now, cancel out all the blocks that are dominated by each spill.
851 * If the bitset is not empty after that, we have reloads that are
852 * not dominated by any spill. */
853 for (s = si->spills; s != NULL; s = s->next) {
854 ir_node *bl = get_nodes_block(s->after);
855 int start = get_Block_dom_tree_pre_num(bl);
856 int end = get_Block_dom_max_subtree_pre_num(bl);
858 bitset_clear_range(reloads, start, end);
861 if (!bitset_is_empty(reloads))
862 be_add_spill(env, si->to_spill, si->to_spill);
865 void be_insert_spills_reloads(spill_env_t *env)
867 const ir_exec_freq *exec_freq = env->exec_freq;
869 ir_nodeset_iterator_t iter;
872 be_timer_push(T_RA_SPILL_APPLY);
874 /* create all phi-ms first, this is needed so, that phis, hanging on
875 spilled phis work correctly */
876 foreach_ir_nodeset(&env->mem_phis, node, iter) {
877 spill_info_t *info = get_spillinfo(env, node);
878 spill_node(env, info);
881 /* process each spilled node */
882 foreach_set(env->spills, spill_info_t*, si) {
884 ir_node *to_spill = si->to_spill;
885 ir_mode *mode = get_irn_mode(to_spill);
886 ir_node **copies = NEW_ARR_F(ir_node*, 0);
887 double all_remat_costs = 0; /** costs when we would remat all nodes */
890 DBG((dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", to_spill));
892 determine_spill_costs(env, si);
894 /* determine possibility of rematerialisations */
896 /* calculate cost savings for each indivial value when it would
897 be rematted instead of reloaded */
898 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
901 int remat_cost_delta;
903 ir_node *reloader = rld->reloader;
905 if (rld->rematted_node != NULL) {
906 DBG((dbg, LEVEL_2, "\tforced remat %+F before %+F\n",
907 rld->rematted_node, reloader));
910 if (rld->remat_cost_delta >= REMAT_COST_INFINITE) {
911 DBG((dbg, LEVEL_2, "\treload before %+F is forbidden\n",
913 all_remat_costs = REMAT_COST_INFINITE;
917 remat_cost = check_remat_conditions_costs(env, to_spill,
919 if (remat_cost >= REMAT_COST_INFINITE) {
920 DBG((dbg, LEVEL_2, "\tremat before %+F not possible\n",
922 rld->remat_cost_delta = REMAT_COST_INFINITE;
923 all_remat_costs = REMAT_COST_INFINITE;
927 remat_cost_delta = remat_cost - env->reload_cost;
928 rld->remat_cost_delta = remat_cost_delta;
929 block = is_Block(reloader) ? reloader : get_nodes_block(reloader);
930 freq = get_block_execfreq(exec_freq, block);
931 all_remat_costs += remat_cost_delta * freq;
932 DBG((dbg, LEVEL_2, "\tremat costs delta before %+F: "
933 "%d (rel %f)\n", reloader, remat_cost_delta,
934 remat_cost_delta * freq));
936 if (all_remat_costs < REMAT_COST_INFINITE) {
937 /* we don't need the costs for the spill if we can remat
939 all_remat_costs -= si->spill_costs;
941 DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
942 env->spill_cost, si->spill_costs));
945 if (all_remat_costs < 0) {
946 DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
952 /* go through all reloads for this spill */
953 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
954 ir_node *copy; /* a reload is a "copy" of the original value */
956 if (rld->rematted_node != NULL) {
957 copy = rld->rematted_node;
958 sched_add_before(rld->reloader, copy);
959 } else if (be_do_remats &&
960 (force_remat || rld->remat_cost_delta < 0)) {
961 copy = do_remat(env, to_spill, rld->reloader);
963 /* make sure we have a spill */
966 /* create a reload, use the first spill for now SSA
967 * reconstruction for memory comes below */
968 assert(si->spills != NULL);
969 copy = be_reload(si->reload_cls, rld->reloader, mode,
971 #ifdef FIRM_STATISTICS
976 DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
977 copy, to_spill, rld->reloader));
978 ARR_APP1(ir_node*, copies, copy);
981 /* if we had any reloads or remats, then we need to reconstruct the
982 * SSA form for the spilled value */
983 if (ARR_LEN(copies) > 0) {
984 be_ssa_construction_env_t senv;
985 /* be_lv_t *lv = be_get_irg_liveness(env->irg); */
987 be_ssa_construction_init(&senv, env->irg);
988 be_ssa_construction_add_copy(&senv, to_spill);
989 be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies));
990 be_ssa_construction_fix_users(&senv, to_spill);
993 /* no need to enable this as long as we invalidate liveness
994 after this function... */
995 be_ssa_construction_update_liveness_phis(&senv);
996 be_liveness_update(to_spill);
997 len = ARR_LEN(copies);
998 for (i = 0; i < len; ++i) {
999 be_liveness_update(lv, copies[i]);
1002 be_ssa_construction_destroy(&senv);
1004 /* need to reconstruct SSA form if we had multiple spills */
1005 if (si->spills != NULL && si->spills->next != NULL) {
1007 int spill_count = 0;
1009 be_ssa_construction_env_t senv;
1011 be_ssa_construction_init(&senv, env->irg);
1013 for ( ; spill != NULL; spill = spill->next) {
1014 /* maybe we rematerialized the value and need no spill */
1015 if (spill->spill == NULL)
1017 be_ssa_construction_add_copy(&senv, spill->spill);
1020 if (spill_count > 1) {
1021 /* all reloads are attached to the first spill, fix them now */
1022 be_ssa_construction_fix_users(&senv, si->spills->spill);
1025 be_ssa_construction_destroy(&senv);
1029 si->reloaders = NULL;
1032 stat_ev_dbl("spill_spills", env->spill_count);
1033 stat_ev_dbl("spill_reloads", env->reload_count);
1034 stat_ev_dbl("spill_remats", env->remat_count);
1035 stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count);
1037 /* Matze: In theory be_ssa_construction should take care of the liveness...
1038 * try to disable this again in the future */
1039 be_liveness_invalidate(be_get_irg_liveness(env->irg));
1041 be_remove_dead_nodes_from_schedule(env->irg);
1043 be_timer_pop(T_RA_SPILL_APPLY);
1046 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);
1047 void be_init_spill(void)
1049 FIRM_DBG_REGISTER(dbg, "firm.be.spill");