Line data Source code
1 : // Copyright 2016 the V8 project authors. All rights reserved.
2 : // Use of this source code is governed by a BSD-style license that can be
3 : // found in the LICENSE file.
4 :
5 : #include "src/compiler/load-elimination.h"
6 :
7 : #include "src/compiler/access-builder.h"
8 : #include "src/compiler/common-operator.h"
9 : #include "src/compiler/js-graph.h"
10 : #include "src/compiler/node-properties.h"
11 : #include "src/compiler/simplified-operator.h"
12 : #include "src/heap/factory.h"
13 : #include "src/objects-inl.h"
14 :
15 : namespace v8 {
16 : namespace internal {
17 : namespace compiler {
18 :
19 : namespace {
20 :
21 341107977 : bool IsRename(Node* node) {
22 341107977 : switch (node->opcode()) {
23 : case IrOpcode::kCheckHeapObject:
24 : case IrOpcode::kFinishRegion:
25 : case IrOpcode::kTypeGuard:
26 840627 : return !node->IsDead();
27 : default:
28 : return false;
29 : }
30 : }
31 :
32 338957497 : Node* ResolveRenames(Node* node) {
33 678376211 : while (IsRename(node)) {
34 : node = node->InputAt(0);
35 : }
36 338957497 : return node;
37 : }
38 :
39 2779629 : bool MayAlias(Node* a, Node* b) {
40 1825575 : if (a != b) {
41 1164503 : if (!NodeProperties::GetType(a).Maybe(NodeProperties::GetType(b))) {
42 : return false;
43 856437 : } else if (IsRename(b)) {
44 23611 : return MayAlias(a, b->InputAt(0));
45 832826 : } else if (IsRename(a)) {
46 355799 : return MayAlias(a->InputAt(0), b);
47 477027 : } else if (b->opcode() == IrOpcode::kAllocate) {
48 65194 : switch (a->opcode()) {
49 : case IrOpcode::kAllocate:
50 : case IrOpcode::kHeapConstant:
51 : case IrOpcode::kParameter:
52 : return false;
53 : default:
54 : break;
55 : }
56 : } else if (a->opcode() == IrOpcode::kAllocate) {
57 134889 : switch (b->opcode()) {
58 : case IrOpcode::kHeapConstant:
59 : case IrOpcode::kParameter:
60 : return false;
61 : default:
62 : break;
63 : }
64 : }
65 : }
66 : return true;
67 : }
68 :
69 : bool MustAlias(Node* a, Node* b) {
70 169310955 : return ResolveRenames(a) == ResolveRenames(b);
71 : }
72 :
73 : } // namespace
74 :
75 75651332 : Reduction LoadElimination::Reduce(Node* node) {
76 37825666 : if (FLAG_trace_turbo_load_elimination) {
77 0 : if (node->op()->EffectInputCount() > 0) {
78 0 : PrintF(" visit #%d:%s", node->id(), node->op()->mnemonic());
79 0 : if (node->op()->ValueInputCount() > 0) {
80 0 : PrintF("(");
81 0 : for (int i = 0; i < node->op()->ValueInputCount(); ++i) {
82 0 : if (i > 0) PrintF(", ");
83 0 : Node* const value = NodeProperties::GetValueInput(node, i);
84 0 : PrintF("#%d:%s", value->id(), value->op()->mnemonic());
85 : }
86 0 : PrintF(")");
87 : }
88 0 : PrintF("\n");
89 0 : for (int i = 0; i < node->op()->EffectInputCount(); ++i) {
90 0 : Node* const effect = NodeProperties::GetEffectInput(node, i);
91 0 : if (AbstractState const* const state = node_states_.Get(effect)) {
92 : PrintF(" state[%i]: #%d:%s\n", i, effect->id(),
93 0 : effect->op()->mnemonic());
94 0 : state->Print();
95 : } else {
96 : PrintF(" no state[%i]: #%d:%s\n", i, effect->id(),
97 0 : effect->op()->mnemonic());
98 : }
99 : }
100 : }
101 : }
102 37825666 : switch (node->opcode()) {
103 : case IrOpcode::kMapGuard:
104 8426 : return ReduceMapGuard(node);
105 : case IrOpcode::kCheckMaps:
106 187559 : return ReduceCheckMaps(node);
107 : case IrOpcode::kCompareMaps:
108 9006 : return ReduceCompareMaps(node);
109 : case IrOpcode::kEnsureWritableFastElements:
110 9443 : return ReduceEnsureWritableFastElements(node);
111 : case IrOpcode::kMaybeGrowFastElements:
112 12923 : return ReduceMaybeGrowFastElements(node);
113 : case IrOpcode::kTransitionElementsKind:
114 958 : return ReduceTransitionElementsKind(node);
115 : case IrOpcode::kLoadField:
116 1576079 : return ReduceLoadField(node, FieldAccessOf(node->op()));
117 : case IrOpcode::kStoreField:
118 2406582 : return ReduceStoreField(node, FieldAccessOf(node->op()));
119 : case IrOpcode::kStoreMessage:
120 57506 : return ReduceStoreField(node, AccessBuilder::ForExternalIntPtr());
121 : case IrOpcode::kLoadMessage:
122 51733 : return ReduceLoadField(node, AccessBuilder::ForExternalIntPtr());
123 : case IrOpcode::kLoadElement:
124 35142 : return ReduceLoadElement(node);
125 : case IrOpcode::kStoreElement:
126 59234 : return ReduceStoreElement(node);
127 : case IrOpcode::kTransitionAndStoreElement:
128 565 : return ReduceTransitionAndStoreElement(node);
129 : case IrOpcode::kStoreTypedElement:
130 5789 : return ReduceStoreTypedElement(node);
131 : case IrOpcode::kEffectPhi:
132 618888 : return ReduceEffectPhi(node);
133 : case IrOpcode::kDead:
134 : break;
135 : case IrOpcode::kStart:
136 : return ReduceStart(node);
137 : default:
138 32317213 : return ReduceOtherNode(node);
139 : }
140 : return NoChange();
141 : }
142 :
143 : namespace {
144 :
145 1603 : bool IsCompatible(MachineRepresentation r1, MachineRepresentation r2) {
146 1603 : if (r1 == r2) return true;
147 232 : return IsAnyTagged(r1) && IsAnyTagged(r2);
148 : }
149 :
150 : } // namespace
151 :
152 37522 : Node* LoadElimination::AbstractElements::Lookup(
153 : Node* object, Node* index, MachineRepresentation representation) const {
154 327374 : for (Element const element : elements_) {
155 291448 : if (element.object == nullptr) continue;
156 : DCHECK_NOT_NULL(element.index);
157 : DCHECK_NOT_NULL(element.value);
158 238167 : if (MustAlias(object, element.object) && MustAlias(index, element.index) &&
159 1603 : IsCompatible(representation, element.representation)) {
160 : return element.value;
161 : }
162 : }
163 : return nullptr;
164 : }
165 :
166 : LoadElimination::AbstractElements const*
167 33774 : LoadElimination::AbstractElements::Kill(Node* object, Node* index,
168 : Zone* zone) const {
169 64424 : for (Element const element : this->elements_) {
170 61129 : if (element.object == nullptr) continue;
171 38707 : if (MayAlias(object, element.object)) {
172 30479 : AbstractElements* that = new (zone) AbstractElements(zone);
173 274311 : for (Element const element : this->elements_) {
174 243832 : if (element.object == nullptr) continue;
175 : DCHECK_NOT_NULL(element.index);
176 : DCHECK_NOT_NULL(element.value);
177 336738 : if (!MayAlias(object, element.object) ||
178 : !NodeProperties::GetType(index).Maybe(
179 322018 : NodeProperties::GetType(element.index))) {
180 103560 : that->elements_[that->next_index_++] = element;
181 : }
182 : }
183 30479 : that->next_index_ %= arraysize(elements_);
184 : return that;
185 : }
186 : }
187 3295 : return this;
188 : }
189 :
190 13789 : bool LoadElimination::AbstractElements::Equals(
191 : AbstractElements const* that) const {
192 13789 : if (this == that) return true;
193 34406 : for (size_t i = 0; i < arraysize(elements_); ++i) {
194 35645 : Element this_element = this->elements_[i];
195 35645 : if (this_element.object == nullptr) continue;
196 16060 : for (size_t j = 0;; ++j) {
197 22631 : if (j == arraysize(elements_)) return false;
198 21392 : Element that_element = that->elements_[j];
199 21392 : if (this_element.object == that_element.object &&
200 5339 : this_element.index == that_element.index &&
201 : this_element.value == that_element.value) {
202 : break;
203 : }
204 16060 : }
205 : }
206 27982 : for (size_t i = 0; i < arraysize(elements_); ++i) {
207 28809 : Element that_element = that->elements_[i];
208 28809 : if (that_element.object == nullptr) continue;
209 9673 : for (size_t j = 0;; ++j) {
210 14788 : if (j == arraysize(elements_)) return false;
211 13961 : Element this_element = this->elements_[j];
212 13961 : if (that_element.object == this_element.object &&
213 4288 : that_element.index == this_element.index &&
214 : that_element.value == this_element.value) {
215 : break;
216 : }
217 9673 : }
218 : }
219 : return true;
220 : }
221 :
222 : LoadElimination::AbstractElements const*
223 7221 : LoadElimination::AbstractElements::Merge(AbstractElements const* that,
224 : Zone* zone) const {
225 7221 : if (this->Equals(that)) return this;
226 1543 : AbstractElements* copy = new (zone) AbstractElements(zone);
227 13887 : for (Element const this_element : this->elements_) {
228 12344 : if (this_element.object == nullptr) continue;
229 15195 : for (Element const that_element : that->elements_) {
230 13756 : if (this_element.object == that_element.object &&
231 946 : this_element.index == that_element.index &&
232 : this_element.value == that_element.value) {
233 939 : copy->elements_[copy->next_index_++] = this_element;
234 939 : break;
235 : }
236 : }
237 : }
238 1543 : copy->next_index_ %= arraysize(elements_);
239 1543 : return copy;
240 : }
241 :
242 0 : void LoadElimination::AbstractElements::Print() const {
243 0 : for (Element const& element : elements_) {
244 0 : if (element.object) {
245 : PrintF(" #%d:%s @ #%d:%s -> #%d:%s\n", element.object->id(),
246 : element.object->op()->mnemonic(), element.index->id(),
247 : element.index->op()->mnemonic(), element.value->id(),
248 0 : element.value->op()->mnemonic());
249 : }
250 : }
251 0 : }
252 :
253 766280 : Node* LoadElimination::AbstractField::Lookup(Node* object) const {
254 170365206 : for (auto pair : info_for_node_) {
255 169074391 : if (pair.first->IsDead()) continue;
256 169074391 : if (MustAlias(object, pair.first)) return pair.second.value;
257 : }
258 : return nullptr;
259 : }
260 :
261 : namespace {
262 :
263 : bool MayAlias(MaybeHandle<Name> x, MaybeHandle<Name> y) {
264 510711 : if (!x.address()) return true;
265 296305 : if (!y.address()) return true;
266 226639 : if (x.address() != y.address()) return false;
267 : return true;
268 : }
269 :
270 : } // namespace
271 :
272 : class LoadElimination::AliasStateInfo {
273 : public:
274 : AliasStateInfo(const AbstractState* state, Node* object, Handle<Map> map)
275 1332 : : state_(state), object_(object), map_(map) {}
276 : AliasStateInfo(const AbstractState* state, Node* object)
277 2322148 : : state_(state), object_(object) {}
278 :
279 : bool MayAlias(Node* other) const;
280 :
281 : private:
282 : const AbstractState* state_;
283 : Node* object_;
284 : MaybeHandle<Map> map_;
285 : };
286 :
287 26336468 : LoadElimination::AbstractField const* LoadElimination::AbstractField::Kill(
288 : const AliasStateInfo& alias_info, MaybeHandle<Name> name,
289 : Zone* zone) const {
290 265223563 : for (auto pair : this->info_for_node_) {
291 213055368 : if (pair.first->IsDead()) continue;
292 213055368 : if (alias_info.MayAlias(pair.first)) {
293 : AbstractField* that = new (zone) AbstractField(zone);
294 1775060 : for (auto pair : this->info_for_node_) {
295 1276289 : if (!alias_info.MayAlias(pair.first) ||
296 : !MayAlias(name, pair.second.name)) {
297 : that->info_for_node_.insert(pair);
298 : }
299 : }
300 : return that;
301 : }
302 : }
303 : return this;
304 : }
305 :
306 0 : void LoadElimination::AbstractField::Print() const {
307 0 : for (auto pair : info_for_node_) {
308 : PrintF(" #%d:%s -> #%d:%s\n", pair.first->id(),
309 : pair.first->op()->mnemonic(), pair.second.value->id(),
310 0 : pair.second.value->op()->mnemonic());
311 : }
312 0 : }
313 :
314 0 : LoadElimination::AbstractMaps::AbstractMaps(Zone* zone)
315 0 : : info_for_node_(zone) {}
316 :
317 115874 : LoadElimination::AbstractMaps::AbstractMaps(Node* object,
318 : ZoneHandleSet<Map> maps, Zone* zone)
319 : : info_for_node_(zone) {
320 115874 : object = ResolveRenames(object);
321 231750 : info_for_node_.insert(std::make_pair(object, maps));
322 115875 : }
323 :
324 96733 : bool LoadElimination::AbstractMaps::Lookup(
325 : Node* object, ZoneHandleSet<Map>* object_maps) const {
326 193466 : auto it = info_for_node_.find(ResolveRenames(object));
327 96733 : if (it == info_for_node_.end()) return false;
328 47950 : *object_maps = it->second;
329 47950 : return true;
330 : }
331 :
332 95663 : LoadElimination::AbstractMaps const* LoadElimination::AbstractMaps::Kill(
333 : const AliasStateInfo& alias_info, Zone* zone) const {
334 28334889 : for (auto pair : this->info_for_node_) {
335 28166273 : if (alias_info.MayAlias(pair.first)) {
336 : AbstractMaps* that = new (zone) AbstractMaps(zone);
337 78670 : for (auto pair : this->info_for_node_) {
338 33250 : if (!alias_info.MayAlias(pair.first)) that->info_for_node_.insert(pair);
339 : }
340 : return that;
341 : }
342 : }
343 : return this;
344 : }
345 :
346 33193 : LoadElimination::AbstractMaps const* LoadElimination::AbstractMaps::Merge(
347 : AbstractMaps const* that, Zone* zone) const {
348 33193 : if (this->Equals(that)) return this;
349 : AbstractMaps* copy = new (zone) AbstractMaps(zone);
350 36315 : for (auto this_it : this->info_for_node_) {
351 16239 : Node* this_object = this_it.first;
352 16239 : ZoneHandleSet<Map> this_maps = this_it.second;
353 : auto that_it = that->info_for_node_.find(this_object);
354 16239 : if (that_it != that->info_for_node_.end() && that_it->second == this_maps) {
355 : copy->info_for_node_.insert(this_it);
356 : }
357 : }
358 10038 : return copy;
359 : }
360 :
361 122980 : LoadElimination::AbstractMaps const* LoadElimination::AbstractMaps::Extend(
362 : Node* object, ZoneHandleSet<Map> maps, Zone* zone) const {
363 : AbstractMaps* that = new (zone) AbstractMaps(zone);
364 : that->info_for_node_ = this->info_for_node_;
365 122980 : object = ResolveRenames(object);
366 122980 : that->info_for_node_[object] = maps;
367 122980 : return that;
368 : }
369 :
370 0 : void LoadElimination::AbstractMaps::Print() const {
371 : AllowHandleDereference allow_handle_dereference;
372 0 : StdoutStream os;
373 0 : for (auto pair : info_for_node_) {
374 0 : os << " #" << pair.first->id() << ":" << pair.first->op()->mnemonic()
375 : << std::endl;
376 : ZoneHandleSet<Map> const& maps = pair.second;
377 0 : for (size_t i = 0; i < maps.size(); ++i) {
378 0 : os << " - " << Brief(*maps[i]) << std::endl;
379 : }
380 0 : }
381 0 : }
382 :
383 54965 : bool LoadElimination::AbstractState::Equals(AbstractState const* that) const {
384 54965 : if (this->elements_) {
385 6582 : if (!that->elements_ || !that->elements_->Equals(this->elements_)) {
386 : return false;
387 : }
388 48383 : } else if (that->elements_) {
389 : return false;
390 : }
391 1705650 : for (size_t i = 0u; i < arraysize(fields_); ++i) {
392 1706823 : AbstractField const* this_field = this->fields_[i];
393 1706823 : AbstractField const* that_field = that->fields_[i];
394 1706823 : if (this_field) {
395 126804 : if (!that_field || !that_field->Equals(this_field)) return false;
396 1643420 : } else if (that_field) {
397 : return false;
398 : }
399 : }
400 53255 : if (this->maps_) {
401 35260 : if (!that->maps_ || !that->maps_->Equals(this->maps_)) {
402 : return false;
403 : }
404 35625 : } else if (that->maps_) {
405 : return false;
406 : }
407 : return true;
408 : }
409 :
410 666689 : void LoadElimination::AbstractState::Merge(AbstractState const* that,
411 : Zone* zone) {
412 : // Merge the information we have about the elements.
413 666689 : if (this->elements_) {
414 : this->elements_ = that->elements_
415 : ? that->elements_->Merge(this->elements_, zone)
416 12244 : : nullptr;
417 : }
418 :
419 : // Merge the information we have about the fields.
420 21333872 : for (size_t i = 0; i < arraysize(fields_); ++i) {
421 21333869 : if (this->fields_[i]) {
422 338828 : if (that->fields_[i]) {
423 267595 : this->fields_[i] = this->fields_[i]->Merge(that->fields_[i], zone);
424 : } else {
425 71233 : this->fields_[i] = nullptr;
426 : }
427 : }
428 : }
429 :
430 : // Merge the information we have about the maps.
431 666692 : if (this->maps_) {
432 42285 : this->maps_ = that->maps_ ? that->maps_->Merge(this->maps_, zone) : nullptr;
433 : }
434 666692 : }
435 :
436 0 : bool LoadElimination::AbstractState::LookupMaps(
437 : Node* object, ZoneHandleSet<Map>* object_map) const {
438 360417 : return this->maps_ && this->maps_->Lookup(object, object_map);
439 : }
440 :
441 238854 : LoadElimination::AbstractState const* LoadElimination::AbstractState::SetMaps(
442 : Node* object, ZoneHandleSet<Map> maps, Zone* zone) const {
443 238854 : AbstractState* that = new (zone) AbstractState(*this);
444 238854 : if (that->maps_) {
445 122980 : that->maps_ = that->maps_->Extend(object, maps, zone);
446 : } else {
447 231748 : that->maps_ = new (zone) AbstractMaps(object, maps, zone);
448 : }
449 238855 : return that;
450 : }
451 :
452 170423 : LoadElimination::AbstractState const* LoadElimination::AbstractState::KillMaps(
453 : const AliasStateInfo& alias_info, Zone* zone) const {
454 170423 : if (this->maps_) {
455 95663 : AbstractMaps const* that_maps = this->maps_->Kill(alias_info, zone);
456 95663 : if (this->maps_ != that_maps) {
457 22710 : AbstractState* that = new (zone) AbstractState(*this);
458 22710 : that->maps_ = that_maps;
459 22710 : return that;
460 : }
461 : }
462 147713 : return this;
463 : }
464 :
465 0 : LoadElimination::AbstractState const* LoadElimination::AbstractState::KillMaps(
466 : Node* object, Zone* zone) const {
467 : AliasStateInfo alias_info(this, object);
468 169655 : return KillMaps(alias_info, zone);
469 : }
470 :
471 0 : Node* LoadElimination::AbstractState::LookupElement(
472 : Node* object, Node* index, MachineRepresentation representation) const {
473 60325 : if (this->elements_) {
474 37522 : return this->elements_->Lookup(object, index, representation);
475 : }
476 : return nullptr;
477 : }
478 :
479 : LoadElimination::AbstractState const*
480 59090 : LoadElimination::AbstractState::AddElement(Node* object, Node* index,
481 : Node* value,
482 : MachineRepresentation representation,
483 : Zone* zone) const {
484 59090 : AbstractState* that = new (zone) AbstractState(*this);
485 59090 : if (that->elements_) {
486 : that->elements_ =
487 36287 : that->elements_->Extend(object, index, value, representation, zone);
488 : } else {
489 : that->elements_ =
490 22803 : new (zone) AbstractElements(object, index, value, representation, zone);
491 : }
492 59090 : return that;
493 : }
494 :
495 : LoadElimination::AbstractState const*
496 44957 : LoadElimination::AbstractState::KillElement(Node* object, Node* index,
497 : Zone* zone) const {
498 44957 : if (this->elements_) {
499 : AbstractElements const* that_elements =
500 33774 : this->elements_->Kill(object, index, zone);
501 33774 : if (this->elements_ != that_elements) {
502 30479 : AbstractState* that = new (zone) AbstractState(*this);
503 30479 : that->elements_ = that_elements;
504 30479 : return that;
505 : }
506 : }
507 14478 : return this;
508 : }
509 :
510 1641264 : LoadElimination::AbstractState const* LoadElimination::AbstractState::AddField(
511 : Node* object, size_t index, Node* value, MaybeHandle<Name> name,
512 : Zone* zone) const {
513 1641263 : AbstractState* that = new (zone) AbstractState(*this);
514 1641263 : if (that->fields_[index]) {
515 : that->fields_[index] =
516 653558 : that->fields_[index]->Extend(object, value, name, zone);
517 : } else {
518 1975410 : that->fields_[index] = new (zone) AbstractField(object, value, name, zone);
519 : }
520 1641265 : return that;
521 : }
522 :
523 0 : LoadElimination::AbstractState const* LoadElimination::AbstractState::KillField(
524 : Node* object, size_t index, MaybeHandle<Name> name, Zone* zone) const {
525 : AliasStateInfo alias_info(this, object);
526 1184353 : return KillField(alias_info, index, name, zone);
527 : }
528 :
529 1184916 : LoadElimination::AbstractState const* LoadElimination::AbstractState::KillField(
530 : const AliasStateInfo& alias_info, size_t index, MaybeHandle<Name> name,
531 : Zone* zone) const {
532 1184916 : if (AbstractField const* this_field = this->fields_[index]) {
533 543388 : this_field = this_field->Kill(alias_info, name, zone);
534 543388 : if (this->fields_[index] != this_field) {
535 157401 : AbstractState* that = new (zone) AbstractState(*this);
536 157401 : that->fields_[index] = this_field;
537 157401 : return that;
538 : }
539 : }
540 1027515 : return this;
541 : }
542 :
543 : LoadElimination::AbstractState const*
544 968140 : LoadElimination::AbstractState::KillFields(Node* object, MaybeHandle<Name> name,
545 : Zone* zone) const {
546 : AliasStateInfo alias_info(this, object);
547 30598054 : for (size_t i = 0;; ++i) {
548 31566194 : if (i == arraysize(fields_)) return this;
549 30610486 : if (AbstractField const* this_field = this->fields_[i]) {
550 : AbstractField const* that_field =
551 25450011 : this_field->Kill(alias_info, name, zone);
552 25450011 : if (that_field != this_field) {
553 12432 : AbstractState* that = new (zone) AbstractState(*this);
554 12432 : that->fields_[i] = that_field;
555 394858 : while (++i < arraysize(fields_)) {
556 369994 : if (this->fields_[i] != nullptr) {
557 343069 : that->fields_[i] = this->fields_[i]->Kill(alias_info, name, zone);
558 : }
559 : }
560 : return that;
561 : }
562 : }
563 30598054 : }
564 : }
565 :
566 0 : Node* LoadElimination::AbstractState::LookupField(Node* object,
567 : size_t index) const {
568 1753987 : if (AbstractField const* this_field = this->fields_[index]) {
569 766280 : return this_field->Lookup(object);
570 : }
571 : return nullptr;
572 : }
573 :
574 242020469 : bool LoadElimination::AliasStateInfo::MayAlias(Node* other) const {
575 : // If {object} is being initialized right here (indicated by {object} being
576 : // an Allocate node instead of a FinishRegion node), we know that {other}
577 : // can only alias with {object} if they refer to exactly the same node.
578 484040938 : if (object_->opcode() == IrOpcode::kAllocate) {
579 240725257 : return object_ == other;
580 : }
581 : // Decide aliasing based on the node kinds.
582 1295212 : if (!compiler::MayAlias(object_, other)) {
583 : return false;
584 : }
585 : // Decide aliasing based on maps (if available).
586 : Handle<Map> map;
587 938538 : if (map_.ToHandle(&map)) {
588 : ZoneHandleSet<Map> other_maps;
589 2734 : if (state_->LookupMaps(other, &other_maps) && other_maps.size() == 1) {
590 1722 : if (map.address() != other_maps.at(0).address()) {
591 546 : return false;
592 : }
593 : }
594 : }
595 : return true;
596 : }
597 :
598 0 : void LoadElimination::AbstractState::Print() const {
599 0 : if (maps_) {
600 0 : PrintF(" maps:\n");
601 0 : maps_->Print();
602 : }
603 0 : if (elements_) {
604 0 : PrintF(" elements:\n");
605 0 : elements_->Print();
606 : }
607 0 : for (size_t i = 0; i < arraysize(fields_); ++i) {
608 0 : if (AbstractField const* const field = fields_[i]) {
609 0 : PrintF(" field %zu:\n", i);
610 0 : field->Print();
611 : }
612 : }
613 0 : }
614 :
615 : LoadElimination::AbstractState const*
616 30340017 : LoadElimination::AbstractStateForEffectNodes::Get(Node* node) const {
617 30340017 : size_t const id = node->id();
618 83876361 : if (id < info_for_node_.size()) return info_for_node_[id];
619 : return nullptr;
620 : }
621 :
622 12504617 : void LoadElimination::AbstractStateForEffectNodes::Set(
623 12504617 : Node* node, AbstractState const* state) {
624 12504617 : size_t const id = node->id();
625 25009234 : if (id >= info_for_node_.size()) info_for_node_.resize(id + 1, nullptr);
626 12504618 : info_for_node_[id] = state;
627 12504618 : }
628 :
629 8426 : Reduction LoadElimination::ReduceMapGuard(Node* node) {
630 8426 : ZoneHandleSet<Map> const maps = MapGuardMapsOf(node->op()).maps();
631 8426 : Node* const object = NodeProperties::GetValueInput(node, 0);
632 8426 : Node* const effect = NodeProperties::GetEffectInput(node);
633 : AbstractState const* state = node_states_.Get(effect);
634 8426 : if (state == nullptr) return NoChange();
635 : ZoneHandleSet<Map> object_maps;
636 7443 : if (state->LookupMaps(object, &object_maps)) {
637 224 : if (maps.contains(object_maps)) return Replace(effect);
638 : // TODO(turbofan): Compute the intersection.
639 : }
640 7355 : state = state->SetMaps(object, maps, zone());
641 7355 : return UpdateState(node, state);
642 : }
643 :
644 187559 : Reduction LoadElimination::ReduceCheckMaps(Node* node) {
645 187559 : ZoneHandleSet<Map> const maps = CheckMapsParametersOf(node->op()).maps();
646 187559 : Node* const object = NodeProperties::GetValueInput(node, 0);
647 187559 : Node* const effect = NodeProperties::GetEffectInput(node);
648 : AbstractState const* state = node_states_.Get(effect);
649 187559 : if (state == nullptr) return NoChange();
650 : ZoneHandleSet<Map> object_maps;
651 104865 : if (state->LookupMaps(object, &object_maps)) {
652 44747 : if (maps.contains(object_maps)) return Replace(effect);
653 : // TODO(turbofan): Compute the intersection.
654 : }
655 60392 : state = state->SetMaps(object, maps, zone());
656 60392 : return UpdateState(node, state);
657 : }
658 :
659 9051 : Reduction LoadElimination::ReduceCompareMaps(Node* node) {
660 9006 : ZoneHandleSet<Map> const maps = CompareMapsParametersOf(node->op()).maps();
661 9006 : Node* const object = NodeProperties::GetValueInput(node, 0);
662 9006 : Node* const effect = NodeProperties::GetEffectInput(node);
663 : AbstractState const* state = node_states_.Get(effect);
664 9006 : if (state == nullptr) return NoChange();
665 : ZoneHandleSet<Map> object_maps;
666 7823 : if (state->LookupMaps(object, &object_maps)) {
667 180 : if (maps.contains(object_maps)) {
668 45 : Node* value = jsgraph()->TrueConstant();
669 45 : ReplaceWithValue(node, value, effect);
670 : return Replace(value);
671 : }
672 : // TODO(turbofan): Compute the intersection.
673 : }
674 7778 : return UpdateState(node, state);
675 : }
676 :
677 9443 : Reduction LoadElimination::ReduceEnsureWritableFastElements(Node* node) {
678 9443 : Node* const object = NodeProperties::GetValueInput(node, 0);
679 9443 : Node* const elements = NodeProperties::GetValueInput(node, 1);
680 9443 : Node* const effect = NodeProperties::GetEffectInput(node);
681 : AbstractState const* state = node_states_.Get(effect);
682 9443 : if (state == nullptr) return NoChange();
683 : // Check if the {elements} already have the fixed array map.
684 : ZoneHandleSet<Map> elements_maps;
685 : ZoneHandleSet<Map> fixed_array_maps(factory()->fixed_array_map());
686 2939 : if (state->LookupMaps(elements, &elements_maps) &&
687 1200 : fixed_array_maps.contains(elements_maps)) {
688 11 : ReplaceWithValue(node, elements, effect);
689 : return Replace(elements);
690 : }
691 : // We know that the resulting elements have the fixed array map.
692 1728 : state = state->SetMaps(node, fixed_array_maps, zone());
693 : // Kill the previous elements on {object}.
694 : state = state->KillField(object, FieldIndexOf(JSObject::kElementsOffset),
695 : MaybeHandle<Name>(), zone());
696 : // Add the new elements on {object}.
697 : state = state->AddField(object, FieldIndexOf(JSObject::kElementsOffset), node,
698 1728 : MaybeHandle<Name>(), zone());
699 1728 : return UpdateState(node, state);
700 : }
701 :
702 12923 : Reduction LoadElimination::ReduceMaybeGrowFastElements(Node* node) {
703 12923 : GrowFastElementsParameters params = GrowFastElementsParametersOf(node->op());
704 12923 : Node* const object = NodeProperties::GetValueInput(node, 0);
705 12923 : Node* const effect = NodeProperties::GetEffectInput(node);
706 : AbstractState const* state = node_states_.Get(effect);
707 12923 : if (state == nullptr) return NoChange();
708 3778 : if (params.mode() == GrowFastElementsMode::kDoubleElements) {
709 : // We know that the resulting elements have the fixed double array map.
710 : state = state->SetMaps(
711 451 : node, ZoneHandleSet<Map>(factory()->fixed_double_array_map()), zone());
712 : } else {
713 : // We know that the resulting elements have the fixed array map or the COW
714 : // version thereof (if we didn't grow and it was already COW before).
715 : ZoneHandleSet<Map> fixed_array_maps(factory()->fixed_array_map());
716 3327 : fixed_array_maps.insert(factory()->fixed_cow_array_map(), zone());
717 3327 : state = state->SetMaps(node, fixed_array_maps, zone());
718 : }
719 : // Kill the previous elements on {object}.
720 : state = state->KillField(object, FieldIndexOf(JSObject::kElementsOffset),
721 : MaybeHandle<Name>(), zone());
722 : // Add the new elements on {object}.
723 : state = state->AddField(object, FieldIndexOf(JSObject::kElementsOffset), node,
724 3778 : MaybeHandle<Name>(), zone());
725 3778 : return UpdateState(node, state);
726 : }
727 :
728 958 : Reduction LoadElimination::ReduceTransitionElementsKind(Node* node) {
729 958 : ElementsTransition transition = ElementsTransitionOf(node->op());
730 958 : Node* const object = NodeProperties::GetValueInput(node, 0);
731 : Handle<Map> source_map(transition.source());
732 : Handle<Map> target_map(transition.target());
733 958 : Node* const effect = NodeProperties::GetEffectInput(node);
734 : AbstractState const* state = node_states_.Get(effect);
735 958 : if (state == nullptr) return NoChange();
736 725 : switch (transition.mode()) {
737 : case ElementsTransition::kFastTransition:
738 : break;
739 : case ElementsTransition::kSlowTransition:
740 : // Kill the elements as well.
741 : AliasStateInfo alias_info(state, object, source_map);
742 : state =
743 : state->KillField(alias_info, FieldIndexOf(JSObject::kElementsOffset),
744 463 : MaybeHandle<Name>(), zone());
745 463 : break;
746 : }
747 : ZoneHandleSet<Map> object_maps;
748 725 : if (state->LookupMaps(object, &object_maps)) {
749 192 : if (ZoneHandleSet<Map>(target_map).contains(object_maps)) {
750 : // The {object} already has the {target_map}, so this TransitionElements
751 : // {node} is fully redundant (independent of what {source_map} is).
752 : return Replace(effect);
753 : }
754 102 : if (object_maps.contains(ZoneHandleSet<Map>(source_map))) {
755 102 : object_maps.remove(source_map, zone());
756 102 : object_maps.insert(target_map, zone());
757 : AliasStateInfo alias_info(state, object, source_map);
758 102 : state = state->KillMaps(alias_info, zone());
759 102 : state = state->SetMaps(object, object_maps, zone());
760 : }
761 : } else {
762 : AliasStateInfo alias_info(state, object, source_map);
763 533 : state = state->KillMaps(alias_info, zone());
764 : }
765 635 : return UpdateState(node, state);
766 : }
767 :
768 1695 : Reduction LoadElimination::ReduceTransitionAndStoreElement(Node* node) {
769 565 : Node* const object = NodeProperties::GetValueInput(node, 0);
770 565 : Handle<Map> double_map(DoubleMapParameterOf(node->op()));
771 565 : Handle<Map> fast_map(FastMapParameterOf(node->op()));
772 565 : Node* const effect = NodeProperties::GetEffectInput(node);
773 : AbstractState const* state = node_states_.Get(effect);
774 565 : if (state == nullptr) return NoChange();
775 :
776 : // We need to add the double and fast maps to the set of possible maps for
777 : // this object, because we don't know which of those we'll transition to.
778 : // Additionally, we should kill all alias information.
779 : ZoneHandleSet<Map> object_maps;
780 257 : if (state->LookupMaps(object, &object_maps)) {
781 0 : object_maps.insert(double_map, zone());
782 0 : object_maps.insert(fast_map, zone());
783 : state = state->KillMaps(object, zone());
784 0 : state = state->SetMaps(object, object_maps, zone());
785 : }
786 : // Kill the elements as well.
787 : state = state->KillField(object, FieldIndexOf(JSObject::kElementsOffset),
788 : MaybeHandle<Name>(), zone());
789 257 : return UpdateState(node, state);
790 : }
791 :
792 1627812 : Reduction LoadElimination::ReduceLoadField(Node* node,
793 14 : FieldAccess const& access) {
794 1627812 : Node* object = NodeProperties::GetValueInput(node, 0);
795 1627812 : Node* effect = NodeProperties::GetEffectInput(node);
796 1627812 : Node* control = NodeProperties::GetControlInput(node);
797 : AbstractState const* state = node_states_.Get(effect);
798 1627812 : if (state == nullptr) return NoChange();
799 1404346 : if (access.offset == HeapObject::kMapOffset &&
800 : access.base_is_tagged == kTaggedBase) {
801 : DCHECK(IsAnyTagged(access.machine_type.representation()));
802 : ZoneHandleSet<Map> object_maps;
803 4062 : if (state->LookupMaps(object, &object_maps) && object_maps.size() == 1) {
804 14 : Node* value = jsgraph()->HeapConstant(object_maps[0]);
805 : NodeProperties::SetType(value, Type::OtherInternal());
806 116132 : ReplaceWithValue(node, value, effect);
807 14 : return Replace(value);
808 : }
809 : } else {
810 1400298 : int field_index = FieldIndexOf(access);
811 1400298 : if (field_index >= 0) {
812 1209614 : if (Node* replacement = state->LookupField(object, field_index)) {
813 : // Make sure we don't resurrect dead {replacement} nodes.
814 116118 : if (!replacement->IsDead()) {
815 : // Introduce a TypeGuard if the type of the {replacement} node is not
816 : // a subtype of the original {node}'s type.
817 116118 : if (!NodeProperties::GetType(replacement)
818 232236 : .Is(NodeProperties::GetType(node))) {
819 : Type replacement_type = Type::Intersect(
820 : NodeProperties::GetType(node),
821 1058 : NodeProperties::GetType(replacement), graph()->zone());
822 : replacement = effect =
823 : graph()->NewNode(common()->TypeGuard(replacement_type),
824 1058 : replacement, effect, control);
825 : NodeProperties::SetType(replacement, replacement_type);
826 : }
827 : ReplaceWithValue(node, replacement, effect);
828 : return Replace(replacement);
829 : }
830 : }
831 488689 : state = state->AddField(object, field_index, node, access.name, zone());
832 : }
833 : }
834 : Handle<Map> field_map;
835 1288214 : if (access.map.ToHandle(&field_map)) {
836 2431 : state = state->SetMaps(node, ZoneHandleSet<Map>(field_map), zone());
837 : }
838 1288214 : return UpdateState(node, state);
839 : }
840 :
841 2464088 : Reduction LoadElimination::ReduceStoreField(Node* node,
842 : FieldAccess const& access) {
843 2464088 : Node* const object = NodeProperties::GetValueInput(node, 0);
844 2464089 : Node* const new_value = NodeProperties::GetValueInput(node, 1);
845 2464089 : Node* const effect = NodeProperties::GetEffectInput(node);
846 : AbstractState const* state = node_states_.Get(effect);
847 2464087 : if (state == nullptr) return NoChange();
848 2280341 : if (access.offset == HeapObject::kMapOffset &&
849 : access.base_is_tagged == kTaggedBase) {
850 : DCHECK(IsAnyTagged(access.machine_type.representation()));
851 : // Kill all potential knowledge about the {object}s map.
852 : state = state->KillMaps(object, zone());
853 163028 : Type const new_value_type = NodeProperties::GetType(new_value);
854 163028 : if (new_value_type.IsHeapConstant()) {
855 : // Record the new {object} map information.
856 : AllowHandleDereference handle_dereference;
857 : ZoneHandleSet<Map> object_maps(
858 163027 : Handle<Map>::cast(new_value_type.AsHeapConstant()->Value()));
859 163027 : state = state->SetMaps(object, object_maps, zone());
860 : }
861 : } else {
862 2117313 : int field_index = FieldIndexOf(access);
863 2117314 : if (field_index >= 0) {
864 1149180 : Node* const old_value = state->LookupField(object, field_index);
865 1149180 : if (old_value == new_value) {
866 : // This store is fully redundant.
867 : return Replace(effect);
868 : }
869 : // Kill all potentially aliasing fields and record the new value.
870 : state = state->KillField(object, field_index, access.name, zone());
871 : state =
872 1147069 : state->AddField(object, field_index, new_value, access.name, zone());
873 : } else {
874 : // Unsupported StoreField operator.
875 968134 : state = state->KillFields(object, access.name, zone());
876 : }
877 : }
878 2278234 : return UpdateState(node, state);
879 : }
880 :
881 55728 : Reduction LoadElimination::ReduceLoadElement(Node* node) {
882 35142 : Node* const object = NodeProperties::GetValueInput(node, 0);
883 35142 : Node* const index = NodeProperties::GetValueInput(node, 1);
884 35142 : Node* const effect = NodeProperties::GetEffectInput(node);
885 : AbstractState const* state = node_states_.Get(effect);
886 35142 : if (state == nullptr) return NoChange();
887 :
888 : // Only handle loads that do not require truncations.
889 20586 : ElementAccess const& access = ElementAccessOf(node->op());
890 39958 : switch (access.machine_type.representation()) {
891 : case MachineRepresentation::kNone:
892 : case MachineRepresentation::kBit:
893 0 : UNREACHABLE();
894 : break;
895 : case MachineRepresentation::kWord8:
896 : case MachineRepresentation::kWord16:
897 : case MachineRepresentation::kWord32:
898 : case MachineRepresentation::kWord64:
899 : case MachineRepresentation::kFloat32:
900 : // TODO(turbofan): Add support for doing the truncations.
901 : break;
902 : case MachineRepresentation::kFloat64:
903 : case MachineRepresentation::kSimd128:
904 : case MachineRepresentation::kTaggedSigned:
905 : case MachineRepresentation::kTaggedPointer:
906 : case MachineRepresentation::kTagged:
907 20586 : if (Node* replacement = state->LookupElement(
908 : object, index, access.machine_type.representation())) {
909 : // Make sure we don't resurrect dead {replacement} nodes.
910 : // Skip lowering if the type of the {replacement} node is not a subtype
911 : // of the original {node}'s type.
912 : // TODO(tebbi): We should insert a {TypeGuard} for the intersection of
913 : // these two types here once we properly handle {Type::None} everywhere.
914 3687 : if (!replacement->IsDead() && NodeProperties::GetType(replacement)
915 3687 : .Is(NodeProperties::GetType(node))) {
916 1214 : ReplaceWithValue(node, replacement, effect);
917 : return Replace(replacement);
918 : }
919 : }
920 : state = state->AddElement(object, index, node,
921 19372 : access.machine_type.representation(), zone());
922 19372 : return UpdateState(node, state);
923 : }
924 : return NoChange();
925 : }
926 :
927 59234 : Reduction LoadElimination::ReduceStoreElement(Node* node) {
928 59234 : ElementAccess const& access = ElementAccessOf(node->op());
929 59234 : Node* const object = NodeProperties::GetValueInput(node, 0);
930 59234 : Node* const index = NodeProperties::GetValueInput(node, 1);
931 59234 : Node* const new_value = NodeProperties::GetValueInput(node, 2);
932 59234 : Node* const effect = NodeProperties::GetEffectInput(node);
933 : AbstractState const* state = node_states_.Get(effect);
934 59234 : if (state == nullptr) return NoChange();
935 : Node* const old_value =
936 79457 : state->LookupElement(object, index, access.machine_type.representation());
937 39739 : if (old_value == new_value) {
938 : // This store is fully redundant.
939 : return Replace(effect);
940 : }
941 : // Kill all potentially aliasing elements.
942 39718 : state = state->KillElement(object, index, zone());
943 : // Only record the new value if the store doesn't have an implicit truncation.
944 : switch (access.machine_type.representation()) {
945 : case MachineRepresentation::kNone:
946 : case MachineRepresentation::kBit:
947 0 : UNREACHABLE();
948 : break;
949 : case MachineRepresentation::kWord8:
950 : case MachineRepresentation::kWord16:
951 : case MachineRepresentation::kWord32:
952 : case MachineRepresentation::kWord64:
953 : case MachineRepresentation::kFloat32:
954 : // TODO(turbofan): Add support for doing the truncations.
955 : break;
956 : case MachineRepresentation::kFloat64:
957 : case MachineRepresentation::kSimd128:
958 : case MachineRepresentation::kTaggedSigned:
959 : case MachineRepresentation::kTaggedPointer:
960 : case MachineRepresentation::kTagged:
961 : state = state->AddElement(object, index, new_value,
962 39718 : access.machine_type.representation(), zone());
963 39718 : break;
964 : }
965 39718 : return UpdateState(node, state);
966 : }
967 :
968 5789 : Reduction LoadElimination::ReduceStoreTypedElement(Node* node) {
969 5789 : Node* const effect = NodeProperties::GetEffectInput(node);
970 : AbstractState const* state = node_states_.Get(effect);
971 5789 : if (state == nullptr) return NoChange();
972 4463 : return UpdateState(node, state);
973 : }
974 :
975 232020 : LoadElimination::AbstractState const* LoadElimination::UpdateStateForPhi(
976 : AbstractState const* state, Node* effect_phi, Node* phi) {
977 232020 : int predecessor_count = phi->InputCount() - 1;
978 : // TODO(jarin) Consider doing a union here. At the moment, we just keep this
979 : // consistent with AbstractState::Merge.
980 :
981 : // Check if all the inputs have the same maps.
982 : AbstractState const* input_state =
983 232020 : node_states_.Get(NodeProperties::GetEffectInput(effect_phi, 0));
984 : ZoneHandleSet<Map> object_maps;
985 232018 : if (!input_state->LookupMaps(phi->InputAt(0), &object_maps)) return state;
986 443 : for (int i = 1; i < predecessor_count; i++) {
987 : input_state =
988 357 : node_states_.Get(NodeProperties::GetEffectInput(effect_phi, i));
989 : ZoneHandleSet<Map> input_maps;
990 669 : if (!input_state->LookupMaps(phi->InputAt(i), &input_maps)) return state;
991 45 : if (input_maps != object_maps) return state;
992 : }
993 41 : return state->SetMaps(phi, object_maps, zone());
994 : }
995 :
996 1000460 : Reduction LoadElimination::ReduceEffectPhi(Node* node) {
997 618886 : Node* const effect0 = NodeProperties::GetEffectInput(node, 0);
998 1087625 : Node* const control = NodeProperties::GetControlInput(node);
999 : AbstractState const* state0 = node_states_.Get(effect0);
1000 618892 : if (state0 == nullptr) return NoChange();
1001 468733 : if (control->opcode() == IrOpcode::kLoop) {
1002 : // Here we rely on having only reducible loops:
1003 : // The loop entry edge always dominates the header, so we can just take
1004 : // the state from the first input, and compute the loop state based on it.
1005 87159 : AbstractState const* state = ComputeLoopState(node, state0);
1006 87159 : return UpdateState(node, state);
1007 : }
1008 : DCHECK_EQ(IrOpcode::kMerge, control->opcode());
1009 :
1010 : // Shortcut for the case when we do not know anything about some input.
1011 381574 : int const input_count = node->op()->EffectInputCount();
1012 2065070 : for (int i = 1; i < input_count; ++i) {
1013 1768055 : Node* const effect = NodeProperties::GetEffectInput(node, i);
1014 1768055 : if (node_states_.Get(effect) == nullptr) return NoChange();
1015 : }
1016 :
1017 : // Make a copy of the first input's state and merge with the state
1018 : // from other inputs.
1019 297016 : AbstractState* state = new (zone()) AbstractState(*state0);
1020 963707 : for (int i = 1; i < input_count; ++i) {
1021 666686 : Node* const input = NodeProperties::GetEffectInput(node, i);
1022 666686 : state->Merge(node_states_.Get(input), zone());
1023 : }
1024 :
1025 : // For each phi, try to compute the new state for the phi from
1026 : // the inputs.
1027 : AbstractState const* state_with_phis = state;
1028 3252960 : for (Node* use : control->uses()) {
1029 1329462 : if (use->opcode() == IrOpcode::kPhi) {
1030 232023 : state_with_phis = UpdateStateForPhi(state_with_phis, node, use);
1031 : }
1032 : }
1033 :
1034 297015 : return UpdateState(node, state_with_phis);
1035 : }
1036 :
1037 0 : Reduction LoadElimination::ReduceStart(Node* node) {
1038 456693 : return UpdateState(node, empty_state());
1039 : }
1040 :
1041 40547997 : Reduction LoadElimination::ReduceOtherNode(Node* node) {
1042 32318145 : if (node->op()->EffectInputCount() == 1) {
1043 10714636 : if (node->op()->EffectOutputCount() == 1) {
1044 9850340 : Node* const effect = NodeProperties::GetEffectInput(node);
1045 : AbstractState const* state = node_states_.Get(effect);
1046 : // If we do not know anything about the predecessor, do not propagate
1047 : // just yet because we will have to recompute anyway once we compute
1048 : // the predecessor.
1049 9850448 : if (state == nullptr) return NoChange();
1050 : // Check if this {node} has some uncontrolled side effects.
1051 8229852 : if (!node->op()->HasProperty(Operator::kNoWrite)) {
1052 2796963 : state = empty_state();
1053 : }
1054 8229852 : return UpdateState(node, state);
1055 : } else {
1056 : // Effect terminators should be handled specially.
1057 : return NoChange();
1058 : }
1059 : }
1060 : DCHECK_EQ(0, node->op()->EffectInputCount());
1061 : DCHECK_EQ(0, node->op()->EffectOutputCount());
1062 : return NoChange();
1063 : }
1064 :
1065 12782617 : Reduction LoadElimination::UpdateState(Node* node, AbstractState const* state) {
1066 : AbstractState const* original = node_states_.Get(node);
1067 : // Only signal that the {node} has Changed, if the information about {state}
1068 : // has changed wrt. the {original}.
1069 12782617 : if (state != original) {
1070 12557872 : if (original == nullptr || !state->Equals(original)) {
1071 12504620 : node_states_.Set(node, state);
1072 : return Changed(node);
1073 : }
1074 : }
1075 : return NoChange();
1076 : }
1077 :
1078 : LoadElimination::AbstractState const*
1079 34676 : LoadElimination::ComputeLoopStateForStoreField(
1080 : Node* current, LoadElimination::AbstractState const* state,
1081 : FieldAccess const& access) const {
1082 34676 : Node* const object = NodeProperties::GetValueInput(current, 0);
1083 34676 : if (access.offset == HeapObject::kMapOffset) {
1084 : // Invalidate what we know about the {object}s map.
1085 : state = state->KillMaps(object, zone());
1086 : } else {
1087 28481 : int field_index = FieldIndexOf(access);
1088 28481 : if (field_index < 0) {
1089 6 : state = state->KillFields(object, access.name, zone());
1090 : } else {
1091 28475 : state = state->KillField(object, field_index, access.name, zone());
1092 : }
1093 : }
1094 34676 : return state;
1095 : }
1096 :
1097 87159 : LoadElimination::AbstractState const* LoadElimination::ComputeLoopState(
1098 : Node* node, AbstractState const* state) const {
1099 87159 : Node* const control = NodeProperties::GetControlInput(node);
1100 : struct TransitionElementsKindInfo {
1101 : ElementsTransition transition;
1102 : Node* object;
1103 : };
1104 : ZoneVector<TransitionElementsKindInfo> element_transitions_(zone());
1105 87159 : ZoneQueue<Node*> queue(zone());
1106 : ZoneSet<Node*> visited(zone());
1107 : visited.insert(node);
1108 348632 : for (int i = 1; i < control->InputCount(); ++i) {
1109 261474 : queue.push(node->InputAt(i));
1110 : }
1111 892575 : while (!queue.empty()) {
1112 869238 : Node* const current = queue.front();
1113 : queue.pop();
1114 869244 : if (visited.find(current) == visited.end()) {
1115 : visited.insert(current);
1116 3161571 : if (!current->op()->HasProperty(Operator::kNoWrite)) {
1117 109257 : switch (current->opcode()) {
1118 : case IrOpcode::kEnsureWritableFastElements: {
1119 759 : Node* const object = NodeProperties::GetValueInput(current, 0);
1120 : state = state->KillField(object,
1121 : FieldIndexOf(JSObject::kElementsOffset),
1122 : MaybeHandle<Name>(), zone());
1123 759 : break;
1124 : }
1125 : case IrOpcode::kMaybeGrowFastElements: {
1126 1854 : Node* const object = NodeProperties::GetValueInput(current, 0);
1127 : state = state->KillField(object,
1128 : FieldIndexOf(JSObject::kElementsOffset),
1129 : MaybeHandle<Name>(), zone());
1130 1854 : break;
1131 : }
1132 : case IrOpcode::kTransitionElementsKind: {
1133 226 : ElementsTransition transition = ElementsTransitionOf(current->op());
1134 226 : Node* const object = NodeProperties::GetValueInput(current, 0);
1135 : ZoneHandleSet<Map> object_maps;
1136 678 : if (!state->LookupMaps(object, &object_maps) ||
1137 : !ZoneHandleSet<Map>(transition.target())
1138 412 : .contains(object_maps)) {
1139 266 : element_transitions_.push_back({transition, object});
1140 : }
1141 : break;
1142 : }
1143 : case IrOpcode::kTransitionAndStoreElement: {
1144 432 : Node* const object = NodeProperties::GetValueInput(current, 0);
1145 : // Invalidate what we know about the {object}s map.
1146 : state = state->KillMaps(object, zone());
1147 : // Kill the elements as well.
1148 : state = state->KillField(object,
1149 : FieldIndexOf(JSObject::kElementsOffset),
1150 : MaybeHandle<Name>(), zone());
1151 432 : break;
1152 : }
1153 : case IrOpcode::kStoreField:
1154 : state = ComputeLoopStateForStoreField(current, state,
1155 31832 : FieldAccessOf(current->op()));
1156 31832 : break;
1157 : case IrOpcode::kStoreMessage:
1158 : state = ComputeLoopStateForStoreField(
1159 2844 : current, state, AccessBuilder::ForExternalIntPtr());
1160 2844 : break;
1161 : case IrOpcode::kStoreElement: {
1162 5239 : Node* const object = NodeProperties::GetValueInput(current, 0);
1163 5239 : Node* const index = NodeProperties::GetValueInput(current, 1);
1164 5239 : state = state->KillElement(object, index, zone());
1165 5239 : break;
1166 : }
1167 : case IrOpcode::kStoreTypedElement: {
1168 : // Doesn't affect anything we track with the state currently.
1169 : break;
1170 : }
1171 : default:
1172 63822 : return empty_state();
1173 : }
1174 : }
1175 4658127 : for (int i = 0; i < current->op()->EffectInputCount(); ++i) {
1176 1624313 : queue.push(NodeProperties::GetEffectInput(current, i));
1177 : }
1178 : }
1179 : }
1180 :
1181 : // Finally, we apply the element transitions. For each transition, we will try
1182 : // to only invalidate information about nodes that can have the transition's
1183 : // source map. The trouble is that an object can be transitioned by some other
1184 : // transition to the source map. In that case, the other transition will
1185 : // invalidate the information, so we are mostly fine.
1186 : //
1187 : // The only bad case is
1188 : //
1189 : // mapA ---fast---> mapB ---slow---> mapC
1190 : //
1191 : // If we process the slow transition first on an object that has mapA, we will
1192 : // ignore the transition because the object does not have its source map
1193 : // (mapB). When we later process the fast transition, we invalidate the
1194 : // object's map, but we keep the information about the object's elements. This
1195 : // is wrong because the elements will be overwritten by the slow transition.
1196 : //
1197 : // Note that the slow-slow case is fine because either of the slow transition
1198 : // will invalidate the elements field, so the processing order does not
1199 : // matter.
1200 : //
1201 : // To handle the bad case properly, we first kill the maps using all
1202 : // transitions. We kill the the fields later when all the transitions are
1203 : // already reflected in the map information.
1204 :
1205 46807 : for (const TransitionElementsKindInfo& t : element_transitions_) {
1206 133 : AliasStateInfo alias_info(state, t.object, t.transition.source());
1207 133 : state = state->KillMaps(alias_info, zone());
1208 : }
1209 46807 : for (const TransitionElementsKindInfo& t : element_transitions_) {
1210 133 : switch (t.transition.mode()) {
1211 : case ElementsTransition::kFastTransition:
1212 : break;
1213 : case ElementsTransition::kSlowTransition: {
1214 101 : AliasStateInfo alias_info(state, t.object, t.transition.source());
1215 : state = state->KillField(alias_info,
1216 : FieldIndexOf(JSObject::kElementsOffset),
1217 101 : MaybeHandle<Name>(), zone());
1218 : break;
1219 : }
1220 : }
1221 : }
1222 : return state;
1223 : }
1224 :
1225 : // static
1226 0 : int LoadElimination::FieldIndexOf(int offset) {
1227 : DCHECK(IsAligned(offset, kTaggedSize));
1228 3477505 : int field_index = offset / kTaggedSize;
1229 3477505 : if (field_index >= static_cast<int>(kMaxTrackedFields)) return -1;
1230 : DCHECK_LT(0, field_index);
1231 1782461 : return field_index - 1;
1232 : }
1233 :
1234 : // static
1235 3546088 : int LoadElimination::FieldIndexOf(FieldAccess const& access) {
1236 3546088 : MachineRepresentation rep = access.machine_type.representation();
1237 : switch (rep) {
1238 : case MachineRepresentation::kNone:
1239 : case MachineRepresentation::kBit:
1240 : case MachineRepresentation::kSimd128:
1241 0 : UNREACHABLE();
1242 : break;
1243 : case MachineRepresentation::kWord32:
1244 : if (kInt32Size != kTaggedSize) {
1245 : return -1; // We currently only track tagged pointer size fields.
1246 : }
1247 : break;
1248 : case MachineRepresentation::kWord64:
1249 : if (kInt64Size != kTaggedSize) {
1250 : return -1; // We currently only track tagged pointer size fields.
1251 : }
1252 : break;
1253 : case MachineRepresentation::kWord8:
1254 : case MachineRepresentation::kWord16:
1255 : case MachineRepresentation::kFloat32:
1256 : return -1; // Currently untracked.
1257 : case MachineRepresentation::kFloat64:
1258 : if (kDoubleSize != kTaggedSize) {
1259 : return -1; // We currently only track tagged pointer size fields.
1260 : }
1261 : break;
1262 : case MachineRepresentation::kTaggedSigned:
1263 : case MachineRepresentation::kTaggedPointer:
1264 : case MachineRepresentation::kTagged:
1265 : // TODO(bmeurer): Check that we never do overlapping load/stores of
1266 : // individual parts of Float64 values.
1267 : break;
1268 : }
1269 3542842 : if (access.base_is_tagged != kTaggedBase) {
1270 : return -1; // We currently only track tagged objects.
1271 : }
1272 6955010 : return FieldIndexOf(access.offset);
1273 : }
1274 :
1275 1058 : CommonOperatorBuilder* LoadElimination::common() const {
1276 1058 : return jsgraph()->common();
1277 : }
1278 :
1279 2116 : Graph* LoadElimination::graph() const { return jsgraph()->graph(); }
1280 :
1281 0 : Isolate* LoadElimination::isolate() const { return jsgraph()->isolate(); }
1282 :
1283 5517 : Factory* LoadElimination::factory() const { return jsgraph()->factory(); }
1284 :
1285 : } // namespace compiler
1286 : } // namespace internal
1287 178779 : } // namespace v8
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