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
34 #include "iredges_t.h"
35 #include "irbackedge_t.h"
45 #include "irnodeset.h"
52 #include "bespillutil.h"
55 #include "bechordal_t.h"
57 #include "bessaconstr.h"
60 #include "beintlive_t.h"
64 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
66 #define REMAT_COST_INFINITE 1000
68 typedef struct reloader_t reloader_t;
71 ir_node *can_spill_after;
73 ir_node *rematted_node;
74 int remat_cost_delta; /** costs needed for rematerialization,
75 compared to placing a reload */
78 typedef struct spill_t spill_t;
81 ir_node *after; /**< spill has to be placed after this node (or earlier) */
85 typedef struct spill_info_t spill_info_t;
87 ir_node *to_spill; /**< the value that should get spilled */
88 reloader_t *reloaders; /**< list of places where the value should get
90 spill_t *spills; /**< list of latest places where spill must be
92 double spill_costs; /**< costs needed for spilling the value */
93 const arch_register_class_t *reload_cls; /** the register class in which the
94 reload should be placed */
95 bool spilled_phi; /* true when the whole Phi has been spilled and
96 will be replaced with a PhiM. false if only the
97 value of the Phi gets spilled */
101 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 spill_info_t **mem_phis; /**< set of all spilled phis. */
110 unsigned spill_count;
111 unsigned reload_count;
112 unsigned remat_count;
113 unsigned spilled_phi_count;
117 * Compare two spill infos.
119 static int cmp_spillinfo(const void *x, const void *y, size_t size)
121 const spill_info_t *xx = (const spill_info_t*)x;
122 const spill_info_t *yy = (const spill_info_t*)y;
125 return xx->to_spill != yy->to_spill;
129 * Returns spill info for a specific value (the value that is to be spilled)
131 static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value)
133 spill_info_t info, *res;
134 int hash = hash_irn(value);
136 info.to_spill = value;
137 res = set_find(spill_info_t, env->spills, &info, sizeof(info), hash);
140 info.reloaders = NULL;
142 info.spill_costs = -1;
143 info.reload_cls = NULL;
144 info.spilled_phi = false;
145 res = set_insert(spill_info_t, 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 env->mem_phis = NEW_ARR_F(spill_info_t*, 0);
160 env->spill_cost = arch_env->spill_cost;
161 env->reload_cost = arch_env->reload_cost;
162 obstack_init(&env->obst);
164 env->spill_count = 0;
165 env->reload_count = 0;
166 env->remat_count = 0;
167 env->spilled_phi_count = 0;
172 void be_delete_spill_env(spill_env_t *env)
174 del_set(env->spills);
175 DEL_ARR_F(env->mem_phis);
176 obstack_free(&env->obst, NULL);
182 * | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___
183 * | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
184 * | __/| | (_| | (_| __/ | _ < __/ | (_) | (_| | (_| \__ \
185 * |_| |_|\__,_|\___\___| |_| \_\___|_|\___/ \__,_|\__,_|___/
189 void be_add_spill(spill_env_t *env, ir_node *to_spill, ir_node *after)
191 spill_info_t *spill_info = get_spillinfo(env, to_spill);
196 assert(!arch_irn_is(skip_Proj_const(to_spill), dont_spill));
197 DB((dbg, LEVEL_1, "Add spill of %+F after %+F\n", to_spill, after));
199 /* Just for safety make sure that we do not insert the spill in front of a phi */
200 assert(!is_Phi(sched_next(after)));
202 /* spills that are dominated by others are not needed */
204 s = spill_info->spills;
205 for ( ; s != NULL; s = s->next) {
206 /* no need to add this spill if it is dominated by another */
207 if (value_dominates(s->after, after)) {
208 DB((dbg, LEVEL_1, "...dominated by %+F, not added\n", s->after));
211 /* remove spills that we dominate */
212 if (value_dominates(after, s->after)) {
213 DB((dbg, LEVEL_1, "...remove old spill at %+F\n", s->after));
215 last->next = s->next;
217 spill_info->spills = s->next;
224 spill = OALLOC(&env->obst, spill_t);
225 spill->after = after;
226 spill->next = spill_info->spills;
229 spill_info->spills = spill;
232 void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before,
233 ir_node *can_spill_after, const arch_register_class_t *reload_cls,
239 assert(!arch_irn_is(skip_Proj_const(to_spill), dont_spill));
241 info = get_spillinfo(env, to_spill);
243 if (is_Phi(to_spill)) {
246 /* create spillinfos for the phi arguments */
247 for (i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
248 ir_node *arg = get_irn_n(to_spill, i);
249 get_spillinfo(env, arg);
253 assert(!be_is_Keep(before));
255 /* put reload into list */
256 rel = OALLOC(&env->obst, reloader_t);
257 rel->next = info->reloaders;
258 rel->reloader = before;
259 rel->rematted_node = NULL;
260 rel->can_spill_after = can_spill_after;
261 rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE;
263 info->reloaders = rel;
264 assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
265 info->reload_cls = reload_cls;
267 DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
268 to_spill, before, allow_remat ? "" : " not"));
271 void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
272 const arch_register_class_t *reload_cls, int allow_remat)
274 be_add_reload2(senv, to_spill, before, to_spill, reload_cls, allow_remat);
278 ir_node *be_get_end_of_block_insertion_point(const ir_node *block)
280 ir_node *last = sched_last(block);
282 /* we might have keeps behind the jump... */
283 while (be_is_Keep(last)) {
284 last = sched_prev(last);
285 assert(!sched_is_end(last));
288 assert(is_cfop(last));
290 /* add the reload before the (cond-)jump */
295 * determine final spill position: it should be after all phis, keep nodes
296 * and behind nodes marked as prolog
298 static ir_node *determine_spill_point(ir_node *node)
300 node = skip_Proj(node);
302 ir_node *next = sched_next(node);
303 if (!is_Phi(next) && !be_is_Keep(next) && !be_is_CopyKeep(next))
311 * Returns the point at which you can insert a node that should be executed
312 * before block @p block when coming from pred @p pos.
314 static ir_node *get_block_insertion_point(ir_node *block, int pos)
318 /* simply add the reload to the beginning of the block if we only have 1
319 * predecessor. We don't need to check for phis as there can't be any in a
320 * block with only 1 pred. */
321 if (get_Block_n_cfgpreds(block) == 1) {
322 assert(!is_Phi(sched_first(block)));
323 return sched_first(block);
326 /* We have to reload the value in pred-block */
327 predblock = get_Block_cfgpred_block(block, pos);
328 return be_get_end_of_block_insertion_point(predblock);
331 void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block,
332 int pos, const arch_register_class_t *reload_cls,
335 ir_node *before = get_block_insertion_point(block, pos);
336 be_add_reload(env, to_spill, before, reload_cls, allow_remat);
339 void be_spill_phi(spill_env_t *env, ir_node *node)
345 assert(is_Phi(node));
347 info = get_spillinfo(env, node);
348 info->spilled_phi = true;
349 ARR_APP1(spill_info_t*, env->mem_phis, info);
351 /* create spills for the phi arguments */
352 block = get_nodes_block(node);
353 for (i = 0, arity = get_irn_arity(node); i < arity; ++i) {
354 ir_node *arg = get_irn_n(node, i);
357 /* some backends have virtual noreg/unknown nodes that are not scheduled
358 * and simply always available. */
359 if (!sched_is_scheduled(arg)) {
360 ir_node *pred_block = get_Block_cfgpred_block(block, i);
361 insert = be_get_end_of_block_insertion_point(pred_block);
362 insert = sched_prev(insert);
364 insert = determine_spill_point(arg);
367 be_add_spill(env, arg, insert);
373 * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___
374 * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __|
375 * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \
376 * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/
380 static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo);
385 * @param senv the spill environment
386 * @param irn the node that should be spilled
387 * @param ctx_irn an user of the spilled node
389 * @return a be_Spill node
391 static void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
393 ir_node *to_spill = spillinfo->to_spill;
394 const ir_node *insn = skip_Proj_const(to_spill);
397 /* determine_spill_costs must have been run before */
398 assert(spillinfo->spill_costs >= 0);
400 /* some backends have virtual noreg/unknown nodes that are not scheduled
401 * and simply always available. */
402 if (!sched_is_scheduled(insn)) {
403 /* override spillinfos or create a new one */
404 ir_graph *irg = get_irn_irg(to_spill);
405 spillinfo->spills->spill = get_irg_no_mem(irg);
406 DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
410 DBG((dbg, LEVEL_1, "spilling %+F ... \n", to_spill));
411 spill = spillinfo->spills;
412 for ( ; spill != NULL; spill = spill->next) {
413 ir_node *after = spill->after;
414 after = determine_spill_point(after);
416 spill->spill = arch_env_new_spill(env->arch_env, to_spill, after);
417 DB((dbg, LEVEL_1, "\t%+F after %+F\n", spill->spill, after));
420 DBG((dbg, LEVEL_1, "\n"));
423 static void spill_node(spill_env_t *env, spill_info_t *spillinfo);
426 * If the first usage of a Phi result would be out of memory
427 * there is no sense in allocating a register for it.
428 * Thus we spill it and all its operands to the same spill slot.
429 * Therefore the phi/dataB becomes a phi/Memory
431 * @param senv the spill environment
432 * @param phi the Phi node that should be spilled
433 * @param ctx_irn an user of the spilled node
435 static void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
437 ir_graph *irg = env->irg;
438 ir_node *phi = spillinfo->to_spill;
439 ir_node *block = get_nodes_block(phi);
447 assert(!get_opt_cse());
448 DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
450 /* build a new PhiM */
451 arity = get_irn_arity(phi);
452 ins = ALLOCAN(ir_node*, arity);
453 unknown = new_r_Unknown(irg, mode_M);
454 for (i = 0; i < arity; ++i) {
458 /* override or replace spills list... */
459 spill = OALLOC(&env->obst, spill_t);
460 spill->after = determine_spill_point(phi);
461 spill->spill = be_new_Phi(block, arity, ins, mode_M, arch_no_register_req);
463 sched_add_after(block, spill->spill);
465 spillinfo->spills = spill;
466 env->spilled_phi_count++;
468 for (i = 0; i < arity; ++i) {
469 ir_node *arg = get_irn_n(phi, i);
470 spill_info_t *arg_info = get_spillinfo(env, arg);
472 determine_spill_costs(env, arg_info);
473 spill_node(env, arg_info);
475 set_irn_n(spill->spill, i, arg_info->spills->spill);
477 DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi,
484 * @param senv the spill environment
485 * @param to_spill the node that should be spilled
487 static void spill_node(spill_env_t *env, spill_info_t *spillinfo)
489 /* node is already spilled */
490 if (spillinfo->spills != NULL && spillinfo->spills->spill != NULL)
493 if (spillinfo->spilled_phi) {
494 spill_phi(env, spillinfo);
496 spill_irn(env, spillinfo);
503 * | _ \ ___ _ __ ___ __ _| |_ ___ _ __(_) __ _| (_)_______
504 * | |_) / _ \ '_ ` _ \ / _` | __/ _ \ '__| |/ _` | | |_ / _ \
505 * | _ < __/ | | | | | (_| | || __/ | | | (_| | | |/ / __/
506 * |_| \_\___|_| |_| |_|\__,_|\__\___|_| |_|\__,_|_|_/___\___|
511 * Tests whether value @p arg is available before node @p reloader
512 * @returns 1 if value is available, 0 otherwise
514 static int is_value_available(spill_env_t *env, const ir_node *arg,
515 const ir_node *reloader)
517 if (is_Unknown(arg) || is_NoMem(arg))
520 if (be_is_Spill(skip_Proj_const(arg)))
523 if (arg == get_irg_frame(env->irg))
528 if (get_irn_mode(arg) == mode_T)
532 * Ignore registers are always available
534 if (arch_irn_is_ignore(arg))
541 * Check if a node is rematerializable. This tests for the following conditions:
543 * - The node itself is rematerializable
544 * - All arguments of the node are available or also rematerialisable
545 * - The costs for the rematerialisation operation is less or equal a limit
547 * Returns the costs needed for rematerialisation or something
548 * >= REMAT_COST_INFINITE if remat is not possible.
550 static int check_remat_conditions_costs(spill_env_t *env,
551 const ir_node *spilled, const ir_node *reloader, int parentcosts)
556 const ir_node *insn = skip_Proj_const(spilled);
558 assert(!be_is_Spill(insn));
559 if (!arch_irn_is(insn, rematerializable))
560 return REMAT_COST_INFINITE;
562 if (be_is_Reload(insn)) {
565 costs += arch_get_op_estimated_cost(insn);
567 if (parentcosts + costs >= env->reload_cost + env->spill_cost) {
568 return REMAT_COST_INFINITE;
570 /* never rematerialize a node which modifies the flags.
571 * (would be better to test whether the flags are actually live at point
574 if (arch_irn_is(insn, modify_flags)) {
575 return REMAT_COST_INFINITE;
579 for (i = 0, arity = get_irn_arity(insn); i < arity; ++i) {
580 ir_node *arg = get_irn_n(insn, i);
582 if (is_value_available(env, arg, reloader))
585 /* we have to rematerialize the argument as well */
588 /* we only support rematerializing 1 argument at the moment,
589 * as multiple arguments could increase register pressure */
590 return REMAT_COST_INFINITE;
593 costs += check_remat_conditions_costs(env, arg, reloader,
594 parentcosts + costs);
595 if (parentcosts + costs >= env->reload_cost + env->spill_cost)
596 return REMAT_COST_INFINITE;
603 * Re-materialize a node.
605 * @param env the spill environment
606 * @param spilled the node that was spilled
607 * @param reloader a irn that requires a reload
609 static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader)
616 if (is_Block(reloader)) {
619 bl = get_nodes_block(reloader);
622 ins = ALLOCAN(ir_node*, get_irn_arity(spilled));
623 for (i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
624 ir_node *arg = get_irn_n(spilled, i);
626 if (is_value_available(env, arg, reloader)) {
629 ins[i] = do_remat(env, arg, reloader);
630 /* don't count the argument rematerialization as an extra remat */
635 /* create a copy of the node */
636 res = new_ir_node(get_irn_dbg_info(spilled), env->irg, bl,
637 get_irn_op(spilled), get_irn_mode(spilled),
638 get_irn_arity(spilled), ins);
639 copy_node_attr(env->irg, spilled, res);
640 arch_env_mark_remat(env->arch_env, res);
642 DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
644 if (! is_Proj(res)) {
645 /* insert in schedule */
647 sched_add_before(reloader, res);
654 double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
656 ir_node *block = get_nodes_block(before);
657 double freq = get_block_execfreq(block);
660 return env->spill_cost * freq;
663 unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
664 const ir_node *before)
667 /* is the node rematerializable? */
668 unsigned costs = check_remat_conditions_costs(env, to_spill, before, 0);
669 if (costs < (unsigned) env->reload_cost)
673 return env->reload_cost;
676 double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
678 ir_node *block = get_nodes_block(before);
679 double freq = get_block_execfreq(block);
682 /* is the node rematerializable? */
683 int costs = check_remat_conditions_costs(env, to_spill, before, 0);
684 if (costs < env->reload_cost)
688 return env->reload_cost * freq;
691 int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat,
692 const ir_node *before)
694 return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE;
697 double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
698 ir_node *block, int pos)
700 ir_node *before = get_block_insertion_point(block, pos);
701 return be_get_reload_costs(env, to_spill, before);
704 ir_node *be_new_spill(ir_node *value, ir_node *after)
706 ir_graph *irg = get_irn_irg(value);
707 ir_node *frame = get_irg_frame(irg);
708 const arch_register_class_t *cls = arch_get_irn_reg_class(value);
709 const arch_register_class_t *cls_frame = arch_get_irn_reg_class(frame);
710 ir_node *block = get_block(after);
712 = be_new_Spill(cls, cls_frame, block, frame, value);
714 sched_add_after(after, spill);
718 ir_node *be_new_reload(ir_node *value, ir_node *spill, ir_node *before)
720 ir_graph *irg = get_irn_irg(value);
721 ir_node *frame = get_irg_frame(irg);
722 ir_node *block = get_block(before);
723 const arch_register_class_t *cls = arch_get_irn_reg_class(value);
724 const arch_register_class_t *cls_frame = arch_get_irn_reg_class(frame);
725 ir_mode *mode = get_irn_mode(value);
728 assert(be_is_Spill(spill) || is_Phi(spill));
729 assert(get_irn_mode(spill) == mode_M);
731 reload = be_new_Reload(cls, cls_frame, block, frame, spill, mode);
732 sched_add_before(before, reload);
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 = get_irg_no_mem(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(spill_block);
787 if (spillinfo->spilled_phi) {
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(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 size_t n_mem_phis = ARR_LEN(env->mem_phis);
870 be_timer_push(T_RA_SPILL_APPLY);
872 /* create all phi-ms first, this is needed so, that phis, hanging on
873 spilled phis work correctly */
874 for (i = 0; i < n_mem_phis; ++i) {
875 spill_info_t *info = env->mem_phis[i];
876 spill_node(env, info);
879 /* process each spilled node */
880 foreach_set(env->spills, spill_info_t, si) {
881 ir_node *to_spill = si->to_spill;
882 ir_node **copies = NEW_ARR_F(ir_node*, 0);
883 double all_remat_costs = 0; /** costs when we would remat all nodes */
884 bool force_remat = false;
887 DBG((dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", to_spill));
889 determine_spill_costs(env, si);
891 /* determine possibility of rematerialisations */
893 /* calculate cost savings for each indivial value when it would
894 be rematted instead of reloaded */
895 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
898 int remat_cost_delta;
900 ir_node *reloader = rld->reloader;
902 if (rld->rematted_node != NULL) {
903 DBG((dbg, LEVEL_2, "\tforced remat %+F before %+F\n",
904 rld->rematted_node, reloader));
907 if (rld->remat_cost_delta >= REMAT_COST_INFINITE) {
908 DBG((dbg, LEVEL_2, "\treload before %+F is forbidden\n",
910 all_remat_costs = REMAT_COST_INFINITE;
914 remat_cost = check_remat_conditions_costs(env, to_spill,
916 if (remat_cost >= REMAT_COST_INFINITE) {
917 DBG((dbg, LEVEL_2, "\tremat before %+F not possible\n",
919 rld->remat_cost_delta = REMAT_COST_INFINITE;
920 all_remat_costs = REMAT_COST_INFINITE;
924 remat_cost_delta = remat_cost - env->reload_cost;
925 rld->remat_cost_delta = remat_cost_delta;
926 block = is_Block(reloader) ? reloader : get_nodes_block(reloader);
927 freq = get_block_execfreq(block);
928 all_remat_costs += remat_cost_delta * freq;
929 DBG((dbg, LEVEL_2, "\tremat costs delta before %+F: "
930 "%d (rel %f)\n", reloader, remat_cost_delta,
931 remat_cost_delta * freq));
933 if (all_remat_costs < REMAT_COST_INFINITE) {
934 /* we don't need the costs for the spill if we can remat
936 all_remat_costs -= si->spill_costs;
938 DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
939 env->spill_cost, si->spill_costs));
942 if (all_remat_costs < 0) {
943 DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
949 /* go through all reloads for this spill */
950 for (rld = si->reloaders; rld != NULL; rld = rld->next) {
951 ir_node *copy; /* a reload is a "copy" of the original value */
953 if (rld->rematted_node != NULL) {
954 copy = rld->rematted_node;
955 sched_add_before(rld->reloader, copy);
956 } else if (be_do_remats &&
957 (force_remat || rld->remat_cost_delta < 0)) {
958 copy = do_remat(env, to_spill, rld->reloader);
960 /* make sure we have a spill */
963 /* create a reload, use the first spill for now SSA
964 * reconstruction for memory comes below */
965 assert(si->spills != NULL);
966 copy = arch_env_new_reload(env->arch_env, si->to_spill,
967 si->spills->spill, rld->reloader);
971 DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
972 copy, to_spill, rld->reloader));
973 ARR_APP1(ir_node*, copies, copy);
976 /* if we had any reloads or remats, then we need to reconstruct the
977 * SSA form for the spilled value */
978 if (ARR_LEN(copies) > 0) {
979 be_ssa_construction_env_t senv;
980 /* be_lv_t *lv = be_get_irg_liveness(env->irg); */
982 be_ssa_construction_init(&senv, env->irg);
983 be_ssa_construction_add_copy(&senv, to_spill);
984 be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies));
985 be_ssa_construction_fix_users(&senv, to_spill);
988 /* no need to enable this as long as we invalidate liveness
989 after this function... */
990 be_ssa_construction_update_liveness_phis(&senv);
991 be_liveness_update(to_spill);
992 len = ARR_LEN(copies);
993 for (i = 0; i < len; ++i) {
994 be_liveness_update(lv, copies[i]);
997 be_ssa_construction_destroy(&senv);
999 /* need to reconstruct SSA form if we had multiple spills */
1000 if (si->spills != NULL && si->spills->next != NULL) {
1002 int spill_count = 0;
1004 be_ssa_construction_env_t senv;
1006 be_ssa_construction_init(&senv, env->irg);
1008 for ( ; spill != NULL; spill = spill->next) {
1009 /* maybe we rematerialized the value and need no spill */
1010 if (spill->spill == NULL)
1012 be_ssa_construction_add_copy(&senv, spill->spill);
1015 if (spill_count > 1) {
1016 /* all reloads are attached to the first spill, fix them now */
1017 be_ssa_construction_fix_users(&senv, si->spills->spill);
1020 be_ssa_construction_destroy(&senv);
1024 si->reloaders = NULL;
1027 stat_ev_dbl("spill_spills", env->spill_count);
1028 stat_ev_dbl("spill_reloads", env->reload_count);
1029 stat_ev_dbl("spill_remats", env->remat_count);
1030 stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count);
1032 /* Matze: In theory be_ssa_construction should take care of the liveness...
1033 * try to disable this again in the future */
1034 be_invalidate_live_sets(env->irg);
1036 be_remove_dead_nodes_from_schedule(env->irg);
1038 be_timer_pop(T_RA_SPILL_APPLY);
1041 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill)
1042 void be_init_spill(void)
1044 FIRM_DBG_REGISTER(dbg, "firm.be.spill");