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
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"
66 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
68 #define REMAT_COST_INFINITE 1000
70 typedef struct reloader_t reloader_t;
73 ir_node *can_spill_after;
75 ir_node *rematted_node;
76 int remat_cost_delta; /** costs needed for rematerialization,
77 compared to placing a reload */
80 typedef struct spill_t spill_t;
83 ir_node *before; /**< spill has to be placed before this node (or earlier) */
87 typedef struct spill_info_t spill_info_t;
89 ir_node *to_spill; /**< the value that should get spilled */
90 reloader_t *reloaders; /**< list of places where the value should get
92 spill_t *spills; /**< list of latest places where spill must be
94 double spill_costs; /**< costs needed for spilling the value */
95 const arch_register_class_t *reload_cls; /** the register class in which the
96 reload should be placed */
100 const arch_env_t *arch_env;
104 int spill_cost; /**< the cost of a single spill node */
105 int reload_cost; /**< the cost of a reload node */
106 set *spills; /**< all spill_info_t's, which must be
108 ir_nodeset_t mem_phis; /**< set of all spilled phis. */
109 ir_exec_freq *exec_freq;
110 unsigned new_nodes_idx; /**< all old nodes idx is smaller than
113 #ifdef FIRM_STATISTICS
114 unsigned spill_count;
115 unsigned reload_count;
116 unsigned remat_count;
117 unsigned spilled_phi_count;
122 * Compare two spill infos.
124 static int cmp_spillinfo(const void *x, const void *y, size_t size)
126 const spill_info_t *xx = x;
127 const spill_info_t *yy = y;
130 return xx->to_spill != yy->to_spill;
134 * Returns spill info for a specific value (the value that is to be spilled)
136 static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value)
138 spill_info_t info, *res;
139 int hash = hash_irn(value);
141 info.to_spill = value;
142 res = set_find(env->spills, &info, sizeof(info), hash);
145 info.reloaders = NULL;
147 info.spill_costs = -1;
148 info.reload_cls = NULL;
149 res = set_insert(env->spills, &info, sizeof(info), hash);
155 spill_env_t *be_new_spill_env(be_irg_t *birg)
157 const arch_env_t *arch_env = birg->main_env->arch_env;
159 spill_env_t *env = xmalloc(sizeof(env[0]));
160 env->spills = new_set(cmp_spillinfo, 1024);
161 env->irg = be_get_birg_irg(birg);
163 env->arch_env = arch_env;
164 ir_nodeset_init(&env->mem_phis);
165 env->spill_cost = arch_env->isa->spill_cost;
166 env->reload_cost = arch_env->isa->reload_cost;
167 env->exec_freq = be_get_birg_exec_freq(birg);
168 obstack_init(&env->obst);
170 #ifdef FIRM_STATISTICS
171 env->spill_count = 0;
172 env->reload_count = 0;
173 env->remat_count = 0;
174 env->spilled_phi_count = 0;
180 void be_delete_spill_env(spill_env_t *env)
182 del_set(env->spills);
183 ir_nodeset_destroy(&env->mem_phis);
184 obstack_free(&env->obst, NULL);
190 * | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___
191 * | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
192 * | __/| | (_| | (_| __/ | _ < __/ | (_) | (_| | (_| \__ \
193 * |_| |_|\__,_|\___\___| |_| \_\___|_|\___/ \__,_|\__,_|___/
197 void be_add_spill(spill_env_t *env, ir_node *to_spill, ir_node *before)
200 spill_info_t *spill_info = get_spillinfo(env, to_spill);
205 assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
206 DB((dbg, LEVEL_1, "Add spill of %+F before %+F\n", to_spill, before));
208 /* spills that are dominated by others are not needed */
210 s = spill_info->spills;
211 for( ; s != NULL; s = s->next) {
212 /* no need to add this spill if it is dominated by another */
213 if(value_dominates(s->before, before)) {
214 DB((dbg, LEVEL_1, "...dominated by %+F, not added\n", s->before));
217 /* remove spills that we dominate */
218 if(value_dominates(before, s->before)) {
219 DB((dbg, LEVEL_1, "...remove old spill at %+F\n", s->before));
221 last->next = s->next;
223 spill_info->spills = s->next;
230 spill = obstack_alloc(&env->obst, sizeof(spill[0]));
231 spill->before = before;
232 spill->next = spill_info->spills;
235 spill_info->spills = spill;
239 void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before,
240 ir_node *rematted_node)
242 spill_info_t *spill_info;
243 reloader_t *reloader;
245 spill_info = get_spillinfo(env, to_spill);
247 /* add the remat information */
248 reloader = obstack_alloc(&env->obst, sizeof(reloader[0]));
249 reloader->next = spill_info->reloaders;
250 reloader->reloader = before;
251 reloader->rematted_node = rematted_node;
252 reloader->remat_cost_delta = 0; /* We will never have a cost win over a
253 reload since we're not even allowed to
256 spill_info->reloaders = reloader;
258 DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n",
262 void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before,
263 ir_node *can_spill_after, const arch_register_class_t *reload_cls,
269 assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
271 info = get_spillinfo(env, to_spill);
273 if (is_Phi(to_spill)) {
276 /* create spillinfos for the phi arguments */
277 for (i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
278 ir_node *arg = get_irn_n(to_spill, i);
279 get_spillinfo(env, arg);
283 assert(!is_Proj(before) && !be_is_Keep(before));
285 /* put reload into list */
286 rel = obstack_alloc(&env->obst, sizeof(rel[0]));
287 rel->next = info->reloaders;
288 rel->reloader = before;
289 rel->rematted_node = NULL;
290 rel->can_spill_after = can_spill_after;
291 rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE;
293 info->reloaders = rel;
294 assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
295 info->reload_cls = reload_cls;
297 DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
298 to_spill, before, allow_remat ? "" : " not"));
301 void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
302 const arch_register_class_t *reload_cls, int allow_remat)
304 be_add_reload2(senv, to_spill, before, to_spill, reload_cls, allow_remat);
308 ir_node *be_get_end_of_block_insertion_point(const ir_node *block)
310 ir_node *last = sched_last(block);
312 /* we might have keeps behind the jump... */
313 while(be_is_Keep(last)) {
314 last = sched_prev(last);
315 assert(!sched_is_end(last));
318 assert(is_cfop(last));
320 /* add the reload before the (cond-)jump */
324 static ir_node *skip_keeps_phis(ir_node *node)
326 node = sched_next(node);
327 while(is_Phi(node) || be_is_Keep(node)) {
328 node = sched_next(node);
334 * Returns the point at which you can insert a node that should be executed
335 * before block @p block when coming from pred @p pos.
337 static ir_node *get_block_insertion_point(ir_node *block, int pos)
341 /* simply add the reload to the beginning of the block if we only have 1
342 * predecessor. We don't need to check for phis as there can't be any in a
343 * block with only 1 pred. */
344 if(get_Block_n_cfgpreds(block) == 1) {
345 assert(!is_Phi(sched_first(block)));
346 return sched_first(block);
349 /* We have to reload the value in pred-block */
350 predblock = get_Block_cfgpred_block(block, pos);
351 return be_get_end_of_block_insertion_point(predblock);
354 void be_add_reload_at_end(spill_env_t *env, ir_node *to_spill,
355 const ir_node *block,
356 const arch_register_class_t *reload_cls,
359 ir_node *before = be_get_end_of_block_insertion_point(block);
360 be_add_reload(env, to_spill, before, reload_cls, allow_remat);
363 void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block,
364 int pos, const arch_register_class_t *reload_cls,
367 ir_node *before = get_block_insertion_point(block, pos);
368 be_add_reload(env, to_spill, before, reload_cls, allow_remat);
371 void be_spill_phi(spill_env_t *env, ir_node *node)
377 assert(is_Phi(node));
379 ir_nodeset_insert(&env->mem_phis, node);
381 /* create spills for the phi arguments */
382 block = get_nodes_block(node);
383 spill = get_spillinfo(env, node);
384 for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
385 ir_node *arg = get_irn_n(node, i);
387 //get_spillinfo(env, arg);
389 /* some backends have virtual noreg/unknown nodes that are not scheduled
390 * and simply always available. */
391 if(!sched_is_scheduled(arg)) {
392 ir_node *pred_block = get_Block_cfgpred_block(block, i);
393 insert = be_get_end_of_block_insertion_point(pred_block);
395 insert = skip_keeps_phis(arg);
398 be_add_spill(env, arg, insert);
404 * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___
405 * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __|
406 * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \
407 * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/
411 static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo);
416 * @param senv the spill environment
417 * @param irn the node that should be spilled
418 * @param ctx_irn an user of the spilled node
420 * @return a be_Spill node
422 static void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
424 ir_node *to_spill = spillinfo->to_spill;
427 /* determine_spill_costs must have been run before */
428 assert(spillinfo->spill_costs >= 0);
430 /* some backends have virtual noreg/unknown nodes that are not scheduled
431 * and simply always available. */
432 if(!sched_is_scheduled(to_spill)) {
433 /* override spillinfos or create a new one */
434 spillinfo->spills->spill = new_NoMem();
435 DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
439 DBG((dbg, LEVEL_1, "spilling %+F ... ", to_spill));
440 spill = spillinfo->spills;
441 for( ; spill != NULL; spill = spill->next) {
442 ir_node *block = get_block(spill->before);
443 ir_node *before = spill->before;
445 /* place all spills before the reloads (as we can't guarantee the
446 * same order as the be_add_spill and be_add_reload calls */
447 while(get_irn_idx(sched_prev(before)) > env->new_nodes_idx) {
448 before = sched_prev(before);
451 spill->spill = be_spill(env->arch_env, block, to_spill);
452 sched_add_before(before, spill->spill);
453 DB((dbg, LEVEL_1, "\t%+F before %+F\n", spill->spill, before));
454 #ifdef FIRM_STATISTICS
458 DBG((dbg, LEVEL_1, "\n"));
461 static void spill_node(spill_env_t *env, spill_info_t *spillinfo);
464 * If the first usage of a Phi result would be out of memory
465 * there is no sense in allocating a register for it.
466 * Thus we spill it and all its operands to the same spill slot.
467 * Therefore the phi/dataB becomes a phi/Memory
469 * @param senv the spill environment
470 * @param phi the Phi node that should be spilled
471 * @param ctx_irn an user of the spilled node
473 static void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
475 ir_graph *irg = env->irg;
476 ir_node *phi = spillinfo->to_spill;
477 ir_node *block = get_nodes_block(phi);
485 assert(!get_opt_cse());
486 DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
488 /* build a new PhiM */
489 arity = get_irn_arity(phi);
490 ins = alloca(sizeof(ir_node*) * arity);
491 unknown = new_r_Unknown(irg, mode_M);
492 for(i = 0; i < arity; ++i) {
496 /* override or replace spills list... */
497 spill = obstack_alloc(&env->obst, sizeof(spill[0]));
498 spill->before = skip_keeps_phis(phi);
499 spill->spill = new_r_Phi(irg, block, arity, ins, mode_M);
502 spillinfo->spills = spill;
503 #ifdef FIRM_STATISTICS
504 env->spilled_phi_count++;
507 for(i = 0; i < arity; ++i) {
508 ir_node *arg = get_irn_n(phi, i);
509 spill_info_t *arg_info = get_spillinfo(env, arg);
511 determine_spill_costs(env, arg_info);
512 spill_node(env, arg_info);
514 set_irn_n(spill->spill, i, arg_info->spills->spill);
516 DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi,
523 * @param senv the spill environment
524 * @param to_spill the node that should be spilled
526 static void spill_node(spill_env_t *env, spill_info_t *spillinfo)
530 /* node is already spilled */
531 if(spillinfo->spills != NULL && spillinfo->spills->spill != NULL)
534 to_spill = spillinfo->to_spill;
536 if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
537 spill_phi(env, spillinfo);
539 spill_irn(env, spillinfo);
546 * | _ \ ___ _ __ ___ __ _| |_ ___ _ __(_) __ _| (_)_______
547 * | |_) / _ \ '_ ` _ \ / _` | __/ _ \ '__| |/ _` | | |_ / _ \
548 * | _ < __/ | | | | | (_| | || __/ | | | (_| | | |/ / __/
549 * |_| \_\___|_| |_| |_|\__,_|\__\___|_| |_|\__,_|_|_/___\___|
554 * Tests whether value @p arg is available before node @p reloader
555 * @returns 1 if value is available, 0 otherwise
557 static int is_value_available(spill_env_t *env, const ir_node *arg,
558 const ir_node *reloader)
560 if(is_Unknown(arg) || arg == new_NoMem())
566 if(arg == get_irg_frame(env->irg))
569 /* hack for now (happens when command should be inserted at end of block) */
570 if(is_Block(reloader)) {
575 * Ignore registers are always available
577 if(arch_irn_is(env->arch_env, arg, ignore)) {
581 /* the following test does not work while spilling,
582 * because the liveness info is not adapted yet to the effects of the
583 * additional spills/reloads.
586 /* we want to remat before the insn reloader
587 * thus an arguments is alive if
588 * - it interferes with the reloaders result
589 * - or it is (last-) used by reloader itself
591 if (values_interfere(env->birg->lv, reloader, arg)) {
595 arity = get_irn_arity(reloader);
596 for (i = 0; i < arity; ++i) {
597 ir_node *rel_arg = get_irn_n(reloader, i);
607 * Checks whether the node can principally be rematerialized
609 static int is_remat_node(spill_env_t *env, const ir_node *node)
611 const arch_env_t *arch_env = env->arch_env;
613 assert(!be_is_Spill(node));
615 if(arch_irn_is(arch_env, node, rematerializable))
622 * Check if a node is rematerializable. This tests for the following conditions:
624 * - The node itself is rematerializable
625 * - All arguments of the node are available or also rematerialisable
626 * - The costs for the rematerialisation operation is less or equal a limit
628 * Returns the costs needed for rematerialisation or something
629 * >= REMAT_COST_INFINITE if remat is not possible.
631 static int check_remat_conditions_costs(spill_env_t *env,
632 const ir_node *spilled, const ir_node *reloader, int parentcosts)
638 if(!is_remat_node(env, spilled))
639 return REMAT_COST_INFINITE;
641 if(be_is_Reload(spilled)) {
644 costs += arch_get_op_estimated_cost(env->arch_env, spilled);
646 if(parentcosts + costs >= env->reload_cost + env->spill_cost) {
647 return REMAT_COST_INFINITE;
649 if(arch_irn_is(env->arch_env, spilled, modify_flags)) {
650 return REMAT_COST_INFINITE;
654 for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
655 ir_node *arg = get_irn_n(spilled, i);
657 if(is_value_available(env, arg, reloader))
660 /* we have to rematerialize the argument as well */
662 /* we only support rematerializing 1 argument at the moment,
663 * so that we don't have to care about register pressure
665 return REMAT_COST_INFINITE;
669 costs += check_remat_conditions_costs(env, arg, reloader,
670 parentcosts + costs);
671 if(parentcosts + costs >= env->reload_cost + env->spill_cost)
672 return REMAT_COST_INFINITE;
679 * Re-materialize a node.
681 * @param senv the spill environment
682 * @param spilled the node that was spilled
683 * @param reloader a irn that requires a reload
685 static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader)
692 if(is_Block(reloader)) {
695 bl = get_nodes_block(reloader);
698 ins = alloca(get_irn_arity(spilled) * sizeof(ins[0]));
699 for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
700 ir_node *arg = get_irn_n(spilled, i);
702 if(is_value_available(env, arg, reloader)) {
705 ins[i] = do_remat(env, arg, reloader);
706 #ifdef FIRM_STATISTICS
707 /* don't count the recursive call as remat */
713 /* create a copy of the node */
714 res = new_ir_node(get_irn_dbg_info(spilled), env->irg, bl,
715 get_irn_op(spilled), get_irn_mode(spilled),
716 get_irn_arity(spilled), ins);
717 copy_node_attr(spilled, res);
718 new_backedge_info(res);
720 DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
722 if (! is_Proj(res)) {
723 /* insert in schedule */
725 sched_add_before(reloader, res);
726 #ifdef FIRM_STATISTICS
734 double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
736 ir_node *block = get_nodes_block(before);
737 double freq = get_block_execfreq(env->exec_freq, block);
740 return env->spill_cost * freq;
743 unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
744 const ir_node *before)
747 /* is the node rematerializable? */
748 unsigned costs = check_remat_conditions_costs(env, to_spill, before, 0);
749 if(costs < (unsigned) env->reload_cost)
753 return env->reload_cost;
756 double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
758 ir_node *block = get_nodes_block(before);
759 double freq = get_block_execfreq(env->exec_freq, block);
762 /* is the node rematerializable? */
763 int costs = check_remat_conditions_costs(env, to_spill, before, 0);
764 if(costs < env->reload_cost)
768 return env->reload_cost * freq;
771 int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat,
772 const ir_node *before)
774 return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE;
777 double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
778 ir_node *block, int pos)
780 ir_node *before = get_block_insertion_point(block, pos);
781 return be_get_reload_costs(env, to_spill, before);
786 * |_ _|_ __ ___ ___ _ __| |_ | _ \ ___| | ___ __ _ __| |___
787 * | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ |/ _ \ / _` |/ _` / __|
788 * | || | | \__ \ __/ | | |_ | _ < __/ | (_) | (_| | (_| \__ \
789 * |___|_| |_|___/\___|_| \__| |_| \_\___|_|\___/ \__,_|\__,_|___/
794 * analyzes how to best spill a node and determine costs for that
796 static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo)
798 ir_node *to_spill = spillinfo->to_spill;
799 ir_node *spill_block;
801 double spill_execfreq;
803 /* already calculated? */
804 if(spillinfo->spill_costs >= 0)
807 assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
808 assert(!be_is_Reload(to_spill));
810 /* some backends have virtual noreg/unknown nodes that are not scheduled
811 * and simply always available.
812 * TODO: this is kinda hairy, the NoMem is correct for an Unknown as Phi
813 * predecessor (of a PhiM) but this test might match other things too...
815 if(!sched_is_scheduled(to_spill)) {
816 /* override spillinfos or create a new one */
817 spill_t *spill = obstack_alloc(&env->obst, sizeof(spill[0]));
818 spill->before = NULL;
820 spill->spill = new_NoMem();
822 spillinfo->spills = spill;
823 spillinfo->spill_costs = 0;
825 DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
829 spill_block = get_nodes_block(to_spill);
830 spill_execfreq = get_block_execfreq(env->exec_freq, spill_block);
832 if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
833 /* TODO calculate correct costs...
834 * (though we can't remat this node anyway so no big problem) */
835 spillinfo->spill_costs = env->spill_cost * spill_execfreq;
839 if(spillinfo->spills != NULL) {
841 double spills_execfreq;
843 /* calculate sum of executaion frequencies of individual spills */
845 s = spillinfo->spills;
846 for( ; s != NULL; s = s->next) {
847 ir_node *spill_block = s->before;
850 if(!is_Block(spill_block)) {
851 spill_block = get_nodes_block(spill_block);
853 freq = get_block_execfreq(env->exec_freq, spill_block);
855 spills_execfreq += freq;
858 DB((dbg, LEVEL_1, "%+F: latespillcosts %f after def: %f\n", to_spill,
859 spills_execfreq * env->spill_cost,
860 spill_execfreq * env->spill_cost));
862 /* multi-/latespill is advantageous -> return*/
863 if(spills_execfreq < spill_execfreq) {
864 DB((dbg, LEVEL_1, "use latespills for %+F\n", to_spill));
865 spillinfo->spill_costs = spills_execfreq * env->spill_cost;
870 /* override spillinfos or create a new one */
871 spill = obstack_alloc(&env->obst, sizeof(spill[0]));
872 spill->before = skip_keeps_phis(to_spill);
876 spillinfo->spills = spill;
877 spillinfo->spill_costs = spill_execfreq * env->spill_cost;
878 DB((dbg, LEVEL_1, "spill %+F after definition\n", to_spill));
881 void be_insert_spills_reloads(spill_env_t *env)
883 ir_graph *irg = env->irg;
884 const arch_env_t *arch_env = env->arch_env;
885 const ir_exec_freq *exec_freq = env->exec_freq;
887 ir_nodeset_iterator_t iter;
890 BE_TIMER_PUSH(t_ra_spill_apply);
892 env->new_nodes_idx = get_irg_last_idx(irg);
894 /* create all phi-ms first, this is needed so, that phis, hanging on
895 spilled phis work correctly */
896 foreach_ir_nodeset(&env->mem_phis, node, iter) {
897 spill_info_t *info = get_spillinfo(env, node);
898 spill_node(env, info);
901 /* process each spilled node */
902 for (si = set_first(env->spills); si; si = set_next(env->spills)) {
904 ir_node *to_spill = si->to_spill;
905 ir_mode *mode = get_irn_mode(to_spill);
906 ir_node **copies = NEW_ARR_F(ir_node*, 0);
907 double all_remat_costs = 0; /** costs when we would remat all nodes */
910 DBG((dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", to_spill));
912 determine_spill_costs(env, si);
914 /* determine possibility of rematerialisations */
916 /* calculate cost savings for each indivial value when it would
917 be rematted instead of reloaded */
918 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
921 int remat_cost_delta;
923 ir_node *reloader = rld->reloader;
925 if(rld->rematted_node != NULL) {
926 DBG((dbg, LEVEL_2, "\tforced remat %+F before %+F\n",
927 rld->rematted_node, reloader));
930 if(rld->remat_cost_delta >= REMAT_COST_INFINITE) {
931 DBG((dbg, LEVEL_2, "\treload before %+F is forbidden\n",
933 all_remat_costs = REMAT_COST_INFINITE;
937 remat_cost = check_remat_conditions_costs(env, to_spill,
939 if(remat_cost >= REMAT_COST_INFINITE) {
940 DBG((dbg, LEVEL_2, "\tremat before %+F not possible\n",
942 rld->remat_cost_delta = REMAT_COST_INFINITE;
943 all_remat_costs = REMAT_COST_INFINITE;
947 remat_cost_delta = remat_cost - env->reload_cost;
948 rld->remat_cost_delta = remat_cost_delta;
949 block = is_Block(reloader) ? reloader : get_nodes_block(reloader);
950 freq = get_block_execfreq(exec_freq, block);
951 all_remat_costs += remat_cost_delta * freq;
952 DBG((dbg, LEVEL_2, "\tremat costs delta before %+F: "
953 "%d (rel %f)\n", reloader, remat_cost_delta,
954 remat_cost_delta * freq));
956 if(all_remat_costs < REMAT_COST_INFINITE) {
957 /* we don't need the costs for the spill if we can remat
959 all_remat_costs -= si->spill_costs;
961 DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
962 env->spill_cost, si->spill_costs));
965 if(all_remat_costs < 0) {
966 DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
972 /* go through all reloads for this spill */
973 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
974 ir_node *copy; /* a reload is a "copy" of the original value */
976 if (rld->rematted_node != NULL) {
977 copy = rld->rematted_node;
978 sched_add_before(rld->reloader, copy);
979 } else if (be_do_remats &&
980 (force_remat || rld->remat_cost_delta < 0)) {
981 copy = do_remat(env, to_spill, rld->reloader);
983 /* make sure we have a spill */
986 /* create a reload, use the first spill for now SSA
987 * reconstruction for memory comes below */
988 assert(si->spills != NULL);
989 copy = be_reload(arch_env, si->reload_cls, rld->reloader, mode,
991 #ifdef FIRM_STATISTICS
996 DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
997 copy, to_spill, rld->reloader));
998 ARR_APP1(ir_node*, copies, copy);
1001 /* if we had any reloads or remats, then we need to reconstruct the
1002 * SSA form for the spilled value */
1003 if (ARR_LEN(copies) > 0) {
1004 be_ssa_construction_env_t senv;
1005 /* be_lv_t *lv = be_get_birg_liveness(env->birg); */
1007 be_ssa_construction_init(&senv, env->birg);
1008 be_ssa_construction_add_copy(&senv, to_spill);
1009 be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies));
1010 be_ssa_construction_fix_users(&senv, to_spill);
1013 /* no need to enable this as long as we invalidate liveness
1014 after this function... */
1015 be_ssa_construction_update_liveness_phis(&senv);
1016 be_liveness_update(to_spill);
1017 len = ARR_LEN(copies);
1018 for(i = 0; i < len; ++i) {
1019 be_liveness_update(lv, copies[i]);
1022 be_ssa_construction_destroy(&senv);
1024 /* need to reconstruct SSA form if we had multiple spills */
1025 if (si->spills != NULL && si->spills->next != NULL) {
1027 int spill_count = 0;
1029 be_ssa_construction_env_t senv;
1031 be_ssa_construction_init(&senv, env->birg);
1033 for( ; spill != NULL; spill = spill->next) {
1034 /* maybe we rematerialized the value and need no spill */
1035 if(spill->spill == NULL)
1037 be_ssa_construction_add_copy(&senv, spill->spill);
1040 if(spill_count > 1) {
1041 /* all reloads are attached to the first spill, fix them now */
1042 be_ssa_construction_fix_users(&senv, si->spills->spill);
1045 be_ssa_construction_destroy(&senv);
1049 si->reloaders = NULL;
1052 stat_ev_dbl("spill_spills", env->spill_count);
1053 stat_ev_dbl("spill_reloads", env->reload_count);
1054 stat_ev_dbl("spill_remats", env->remat_count);
1055 stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count);
1057 /* Matze: In theory be_ssa_construction should take care of the liveness...
1058 * try to disable this again in the future */
1059 be_liveness_invalidate(env->birg->lv);
1061 be_remove_dead_nodes_from_schedule(env->birg);
1063 BE_TIMER_POP(t_ra_spill_apply);
1066 void be_init_spill(void)
1068 FIRM_DBG_REGISTER(dbg, "firm.be.spill");
1071 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);