1 // Copyright 2012 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.
10 #include "src/allocation.h"
11 #include "src/hydrogen.h"
12 #include "src/safepoint-table.h"
13 #include "src/zone-allocator.h"
18 #define LITHIUM_OPERAND_LIST(V) \
19 V(ConstantOperand, CONSTANT_OPERAND, 128) \
20 V(StackSlot, STACK_SLOT, 128) \
21 V(DoubleStackSlot, DOUBLE_STACK_SLOT, 128) \
22 V(Register, REGISTER, 16) \
23 V(DoubleRegister, DOUBLE_REGISTER, 16)
26 class LOperand : public ZoneObject {
38 LOperand() : value_(KindField::encode(INVALID)) { }
40 Kind kind() const { return KindField::decode(value_); }
41 int index() const { return static_cast<int>(value_) >> kKindFieldWidth; }
42 #define LITHIUM_OPERAND_PREDICATE(name, type, number) \
43 bool Is##name() const { return kind() == type; }
44 LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_PREDICATE)
45 LITHIUM_OPERAND_PREDICATE(Unallocated, UNALLOCATED, 0)
46 LITHIUM_OPERAND_PREDICATE(Ignored, INVALID, 0)
47 #undef LITHIUM_OPERAND_PREDICATE
48 bool Equals(LOperand* other) const { return value_ == other->value_; }
50 void PrintTo(StringStream* stream);
51 void ConvertTo(Kind kind, int index) {
52 value_ = KindField::encode(kind);
53 value_ |= index << kKindFieldWidth;
54 ASSERT(this->index() == index);
57 // Calls SetUpCache()/TearDownCache() for each subclass.
58 static void SetUpCaches();
59 static void TearDownCaches();
62 static const int kKindFieldWidth = 3;
63 class KindField : public BitField<Kind, 0, kKindFieldWidth> { };
65 LOperand(Kind kind, int index) { ConvertTo(kind, index); }
71 class LUnallocated : public LOperand {
82 FIXED_DOUBLE_REGISTER,
84 MUST_HAVE_DOUBLE_REGISTER,
89 // Lifetime of operand inside the instruction.
91 // USED_AT_START operand is guaranteed to be live only at
92 // instruction start. Register allocator is free to assign the same register
93 // to some other operand used inside instruction (i.e. temporary or
97 // USED_AT_END operand is treated as live until the end of
98 // instruction. This means that register allocator will not reuse it's
99 // register for any other operand inside instruction.
103 explicit LUnallocated(ExtendedPolicy policy) : LOperand(UNALLOCATED, 0) {
104 value_ |= BasicPolicyField::encode(EXTENDED_POLICY);
105 value_ |= ExtendedPolicyField::encode(policy);
106 value_ |= LifetimeField::encode(USED_AT_END);
109 LUnallocated(BasicPolicy policy, int index) : LOperand(UNALLOCATED, 0) {
110 ASSERT(policy == FIXED_SLOT);
111 value_ |= BasicPolicyField::encode(policy);
112 value_ |= index << FixedSlotIndexField::kShift;
113 ASSERT(this->fixed_slot_index() == index);
116 LUnallocated(ExtendedPolicy policy, int index) : LOperand(UNALLOCATED, 0) {
117 ASSERT(policy == FIXED_REGISTER || policy == FIXED_DOUBLE_REGISTER);
118 value_ |= BasicPolicyField::encode(EXTENDED_POLICY);
119 value_ |= ExtendedPolicyField::encode(policy);
120 value_ |= LifetimeField::encode(USED_AT_END);
121 value_ |= FixedRegisterField::encode(index);
124 LUnallocated(ExtendedPolicy policy, Lifetime lifetime)
125 : LOperand(UNALLOCATED, 0) {
126 value_ |= BasicPolicyField::encode(EXTENDED_POLICY);
127 value_ |= ExtendedPolicyField::encode(policy);
128 value_ |= LifetimeField::encode(lifetime);
131 LUnallocated* CopyUnconstrained(Zone* zone) {
132 LUnallocated* result = new(zone) LUnallocated(ANY);
133 result->set_virtual_register(virtual_register());
137 static LUnallocated* cast(LOperand* op) {
138 ASSERT(op->IsUnallocated());
139 return reinterpret_cast<LUnallocated*>(op);
142 // The encoding used for LUnallocated operands depends on the policy that is
143 // stored within the operand. The FIXED_SLOT policy uses a compact encoding
144 // because it accommodates a larger pay-load.
146 // For FIXED_SLOT policy:
147 // +------------------------------------------+
148 // | slot_index | vreg | 0 | 001 |
149 // +------------------------------------------+
151 // For all other (extended) policies:
152 // +------------------------------------------+
153 // | reg_index | L | PPP | vreg | 1 | 001 | L ... Lifetime
154 // +------------------------------------------+ P ... Policy
156 // The slot index is a signed value which requires us to decode it manually
157 // instead of using the BitField utility class.
159 // The superclass has a KindField.
160 STATIC_ASSERT(kKindFieldWidth == 3);
162 // BitFields for all unallocated operands.
163 class BasicPolicyField : public BitField<BasicPolicy, 3, 1> {};
164 class VirtualRegisterField : public BitField<unsigned, 4, 18> {};
166 // BitFields specific to BasicPolicy::FIXED_SLOT.
167 class FixedSlotIndexField : public BitField<int, 22, 10> {};
169 // BitFields specific to BasicPolicy::EXTENDED_POLICY.
170 class ExtendedPolicyField : public BitField<ExtendedPolicy, 22, 3> {};
171 class LifetimeField : public BitField<Lifetime, 25, 1> {};
172 class FixedRegisterField : public BitField<int, 26, 6> {};
174 static const int kMaxVirtualRegisters = VirtualRegisterField::kMax + 1;
175 static const int kFixedSlotIndexWidth = FixedSlotIndexField::kSize;
176 static const int kMaxFixedSlotIndex = (1 << (kFixedSlotIndexWidth - 1)) - 1;
177 static const int kMinFixedSlotIndex = -(1 << (kFixedSlotIndexWidth - 1));
179 // Predicates for the operand policy.
180 bool HasAnyPolicy() const {
181 return basic_policy() == EXTENDED_POLICY &&
182 extended_policy() == ANY;
184 bool HasFixedPolicy() const {
185 return basic_policy() == FIXED_SLOT ||
186 extended_policy() == FIXED_REGISTER ||
187 extended_policy() == FIXED_DOUBLE_REGISTER;
189 bool HasRegisterPolicy() const {
190 return basic_policy() == EXTENDED_POLICY && (
191 extended_policy() == WRITABLE_REGISTER ||
192 extended_policy() == MUST_HAVE_REGISTER);
194 bool HasDoubleRegisterPolicy() const {
195 return basic_policy() == EXTENDED_POLICY &&
196 extended_policy() == MUST_HAVE_DOUBLE_REGISTER;
198 bool HasSameAsInputPolicy() const {
199 return basic_policy() == EXTENDED_POLICY &&
200 extended_policy() == SAME_AS_FIRST_INPUT;
202 bool HasFixedSlotPolicy() const {
203 return basic_policy() == FIXED_SLOT;
205 bool HasFixedRegisterPolicy() const {
206 return basic_policy() == EXTENDED_POLICY &&
207 extended_policy() == FIXED_REGISTER;
209 bool HasFixedDoubleRegisterPolicy() const {
210 return basic_policy() == EXTENDED_POLICY &&
211 extended_policy() == FIXED_DOUBLE_REGISTER;
213 bool HasWritableRegisterPolicy() const {
214 return basic_policy() == EXTENDED_POLICY &&
215 extended_policy() == WRITABLE_REGISTER;
218 // [basic_policy]: Distinguish between FIXED_SLOT and all other policies.
219 BasicPolicy basic_policy() const {
220 return BasicPolicyField::decode(value_);
223 // [extended_policy]: Only for non-FIXED_SLOT. The finer-grained policy.
224 ExtendedPolicy extended_policy() const {
225 ASSERT(basic_policy() == EXTENDED_POLICY);
226 return ExtendedPolicyField::decode(value_);
229 // [fixed_slot_index]: Only for FIXED_SLOT.
230 int fixed_slot_index() const {
231 ASSERT(HasFixedSlotPolicy());
232 return static_cast<int>(value_) >> FixedSlotIndexField::kShift;
235 // [fixed_register_index]: Only for FIXED_REGISTER or FIXED_DOUBLE_REGISTER.
236 int fixed_register_index() const {
237 ASSERT(HasFixedRegisterPolicy() || HasFixedDoubleRegisterPolicy());
238 return FixedRegisterField::decode(value_);
241 // [virtual_register]: The virtual register ID for this operand.
242 int virtual_register() const {
243 return VirtualRegisterField::decode(value_);
245 void set_virtual_register(unsigned id) {
246 value_ = VirtualRegisterField::update(value_, id);
249 // [lifetime]: Only for non-FIXED_SLOT.
250 bool IsUsedAtStart() {
251 ASSERT(basic_policy() == EXTENDED_POLICY);
252 return LifetimeField::decode(value_) == USED_AT_START;
257 class LMoveOperands V8_FINAL BASE_EMBEDDED {
259 LMoveOperands(LOperand* source, LOperand* destination)
260 : source_(source), destination_(destination) {
263 LOperand* source() const { return source_; }
264 void set_source(LOperand* operand) { source_ = operand; }
266 LOperand* destination() const { return destination_; }
267 void set_destination(LOperand* operand) { destination_ = operand; }
269 // The gap resolver marks moves as "in-progress" by clearing the
270 // destination (but not the source).
271 bool IsPending() const {
272 return destination_ == NULL && source_ != NULL;
275 // True if this move a move into the given destination operand.
276 bool Blocks(LOperand* operand) const {
277 return !IsEliminated() && source()->Equals(operand);
280 // A move is redundant if it's been eliminated, if its source and
281 // destination are the same, or if its destination is unneeded.
282 bool IsRedundant() const {
283 return IsEliminated() || source_->Equals(destination_) || IsIgnored();
286 bool IsIgnored() const {
287 return destination_ != NULL && destination_->IsIgnored();
290 // We clear both operands to indicate move that's been eliminated.
291 void Eliminate() { source_ = destination_ = NULL; }
292 bool IsEliminated() const {
293 ASSERT(source_ != NULL || destination_ == NULL);
294 return source_ == NULL;
299 LOperand* destination_;
303 template<LOperand::Kind kOperandKind, int kNumCachedOperands>
304 class LSubKindOperand V8_FINAL : public LOperand {
306 static LSubKindOperand* Create(int index, Zone* zone) {
308 if (index < kNumCachedOperands) return &cache[index];
309 return new(zone) LSubKindOperand(index);
312 static LSubKindOperand* cast(LOperand* op) {
313 ASSERT(op->kind() == kOperandKind);
314 return reinterpret_cast<LSubKindOperand*>(op);
317 static void SetUpCache();
318 static void TearDownCache();
321 static LSubKindOperand* cache;
323 LSubKindOperand() : LOperand() { }
324 explicit LSubKindOperand(int index) : LOperand(kOperandKind, index) { }
328 #define LITHIUM_TYPEDEF_SUBKIND_OPERAND_CLASS(name, type, number) \
329 typedef LSubKindOperand<LOperand::type, number> L##name;
330 LITHIUM_OPERAND_LIST(LITHIUM_TYPEDEF_SUBKIND_OPERAND_CLASS)
331 #undef LITHIUM_TYPEDEF_SUBKIND_OPERAND_CLASS
334 class LParallelMove V8_FINAL : public ZoneObject {
336 explicit LParallelMove(Zone* zone) : move_operands_(4, zone) { }
338 void AddMove(LOperand* from, LOperand* to, Zone* zone) {
339 move_operands_.Add(LMoveOperands(from, to), zone);
342 bool IsRedundant() const;
344 const ZoneList<LMoveOperands>* move_operands() const {
345 return &move_operands_;
348 void PrintDataTo(StringStream* stream) const;
351 ZoneList<LMoveOperands> move_operands_;
355 class LPointerMap V8_FINAL : public ZoneObject {
357 explicit LPointerMap(Zone* zone)
358 : pointer_operands_(8, zone),
359 untagged_operands_(0, zone),
360 lithium_position_(-1) { }
362 const ZoneList<LOperand*>* GetNormalizedOperands() {
363 for (int i = 0; i < untagged_operands_.length(); ++i) {
364 RemovePointer(untagged_operands_[i]);
366 untagged_operands_.Clear();
367 return &pointer_operands_;
369 int lithium_position() const { return lithium_position_; }
371 void set_lithium_position(int pos) {
372 ASSERT(lithium_position_ == -1);
373 lithium_position_ = pos;
376 void RecordPointer(LOperand* op, Zone* zone);
377 void RemovePointer(LOperand* op);
378 void RecordUntagged(LOperand* op, Zone* zone);
379 void PrintTo(StringStream* stream);
382 ZoneList<LOperand*> pointer_operands_;
383 ZoneList<LOperand*> untagged_operands_;
384 int lithium_position_;
388 class LEnvironment V8_FINAL : public ZoneObject {
390 LEnvironment(Handle<JSFunction> closure,
391 FrameType frame_type,
397 HEnterInlined* entry,
400 frame_type_(frame_type),
401 arguments_stack_height_(argument_count),
402 deoptimization_index_(Safepoint::kNoDeoptimizationIndex),
403 translation_index_(-1),
405 translation_size_(value_count),
406 parameter_count_(parameter_count),
408 values_(value_count, zone),
409 is_tagged_(value_count, zone),
410 is_uint32_(value_count, zone),
411 object_mapping_(0, zone),
415 has_been_used_(false) { }
417 Handle<JSFunction> closure() const { return closure_; }
418 FrameType frame_type() const { return frame_type_; }
419 int arguments_stack_height() const { return arguments_stack_height_; }
420 int deoptimization_index() const { return deoptimization_index_; }
421 int translation_index() const { return translation_index_; }
422 BailoutId ast_id() const { return ast_id_; }
423 int translation_size() const { return translation_size_; }
424 int parameter_count() const { return parameter_count_; }
425 int pc_offset() const { return pc_offset_; }
426 const ZoneList<LOperand*>* values() const { return &values_; }
427 LEnvironment* outer() const { return outer_; }
428 HEnterInlined* entry() { return entry_; }
429 Zone* zone() const { return zone_; }
431 bool has_been_used() const { return has_been_used_; }
432 void set_has_been_used() { has_been_used_ = true; }
434 void AddValue(LOperand* operand,
435 Representation representation,
437 values_.Add(operand, zone());
438 if (representation.IsSmiOrTagged()) {
440 is_tagged_.Add(values_.length() - 1, zone());
444 is_uint32_.Add(values_.length() - 1, zone());
448 bool HasTaggedValueAt(int index) const {
449 return is_tagged_.Contains(index);
452 bool HasUint32ValueAt(int index) const {
453 return is_uint32_.Contains(index);
456 void AddNewObject(int length, bool is_arguments) {
457 uint32_t encoded = LengthOrDupeField::encode(length) |
458 IsArgumentsField::encode(is_arguments) |
459 IsDuplicateField::encode(false);
460 object_mapping_.Add(encoded, zone());
463 void AddDuplicateObject(int dupe_of) {
464 uint32_t encoded = LengthOrDupeField::encode(dupe_of) |
465 IsDuplicateField::encode(true);
466 object_mapping_.Add(encoded, zone());
469 int ObjectDuplicateOfAt(int index) {
470 ASSERT(ObjectIsDuplicateAt(index));
471 return LengthOrDupeField::decode(object_mapping_[index]);
474 int ObjectLengthAt(int index) {
475 ASSERT(!ObjectIsDuplicateAt(index));
476 return LengthOrDupeField::decode(object_mapping_[index]);
479 bool ObjectIsArgumentsAt(int index) {
480 ASSERT(!ObjectIsDuplicateAt(index));
481 return IsArgumentsField::decode(object_mapping_[index]);
484 bool ObjectIsDuplicateAt(int index) {
485 return IsDuplicateField::decode(object_mapping_[index]);
488 void Register(int deoptimization_index,
489 int translation_index,
491 ASSERT(!HasBeenRegistered());
492 deoptimization_index_ = deoptimization_index;
493 translation_index_ = translation_index;
494 pc_offset_ = pc_offset;
496 bool HasBeenRegistered() const {
497 return deoptimization_index_ != Safepoint::kNoDeoptimizationIndex;
500 void PrintTo(StringStream* stream);
502 // Marker value indicating a de-materialized object.
503 static LOperand* materialization_marker() { return NULL; }
505 // Encoding used for the object_mapping map below.
506 class LengthOrDupeField : public BitField<int, 0, 30> { };
507 class IsArgumentsField : public BitField<bool, 30, 1> { };
508 class IsDuplicateField : public BitField<bool, 31, 1> { };
511 Handle<JSFunction> closure_;
512 FrameType frame_type_;
513 int arguments_stack_height_;
514 int deoptimization_index_;
515 int translation_index_;
517 int translation_size_;
518 int parameter_count_;
521 // Value array: [parameters] [locals] [expression stack] [de-materialized].
522 // |>--------- translation_size ---------<|
523 ZoneList<LOperand*> values_;
524 GrowableBitVector is_tagged_;
525 GrowableBitVector is_uint32_;
527 // Map with encoded information about materialization_marker operands.
528 ZoneList<uint32_t> object_mapping_;
530 LEnvironment* outer_;
531 HEnterInlined* entry_;
537 // Iterates over the non-null, non-constant operands in an environment.
538 class ShallowIterator V8_FINAL BASE_EMBEDDED {
540 explicit ShallowIterator(LEnvironment* env)
542 limit_(env != NULL ? env->values()->length() : 0),
547 bool Done() { return current_ >= limit_; }
549 LOperand* Current() {
551 ASSERT(env_->values()->at(current_) != NULL);
552 return env_->values()->at(current_);
561 LEnvironment* env() { return env_; }
564 bool ShouldSkip(LOperand* op) {
565 return op == NULL || op->IsConstantOperand();
568 // Skip until something interesting, beginning with and including current_.
569 void SkipUninteresting() {
570 while (current_ < limit_ && ShouldSkip(env_->values()->at(current_))) {
581 // Iterator for non-null, non-constant operands incl. outer environments.
582 class DeepIterator V8_FINAL BASE_EMBEDDED {
584 explicit DeepIterator(LEnvironment* env)
585 : current_iterator_(env) {
589 bool Done() { return current_iterator_.Done(); }
591 LOperand* Current() {
592 ASSERT(!current_iterator_.Done());
593 ASSERT(current_iterator_.Current() != NULL);
594 return current_iterator_.Current();
598 current_iterator_.Advance();
603 void SkipUninteresting() {
604 while (current_iterator_.env() != NULL && current_iterator_.Done()) {
605 current_iterator_ = ShallowIterator(current_iterator_.env()->outer());
609 ShallowIterator current_iterator_;
613 class LPlatformChunk;
617 // Superclass providing data and behavior common to all the
618 // arch-specific LPlatformChunk classes.
619 class LChunk : public ZoneObject {
621 static LChunk* NewChunk(HGraph* graph);
623 void AddInstruction(LInstruction* instruction, HBasicBlock* block);
624 LConstantOperand* DefineConstantOperand(HConstant* constant);
625 HConstant* LookupConstant(LConstantOperand* operand) const;
626 Representation LookupLiteralRepresentation(LConstantOperand* operand) const;
628 int ParameterAt(int index);
629 int GetParameterStackSlot(int index) const;
630 int spill_slot_count() const { return spill_slot_count_; }
631 CompilationInfo* info() const { return info_; }
632 HGraph* graph() const { return graph_; }
633 Isolate* isolate() const { return graph_->isolate(); }
634 const ZoneList<LInstruction*>* instructions() const { return &instructions_; }
635 void AddGapMove(int index, LOperand* from, LOperand* to);
636 LGap* GetGapAt(int index) const;
637 bool IsGapAt(int index) const;
638 int NearestGapPos(int index) const;
639 void MarkEmptyBlocks();
640 const ZoneList<LPointerMap*>* pointer_maps() const { return &pointer_maps_; }
641 LLabel* GetLabel(int block_id) const;
642 int LookupDestination(int block_id) const;
643 Label* GetAssemblyLabel(int block_id) const;
645 const ZoneList<Handle<JSFunction> >* inlined_closures() const {
646 return &inlined_closures_;
649 void AddInlinedClosure(Handle<JSFunction> closure) {
650 inlined_closures_.Add(closure, zone());
653 void AddDeprecationDependency(Handle<Map> map) {
654 ASSERT(!map->is_deprecated());
655 if (!map->CanBeDeprecated()) return;
656 ASSERT(!info_->IsStub());
657 deprecation_dependencies_.insert(map);
660 void AddStabilityDependency(Handle<Map> map) {
661 ASSERT(map->is_stable());
662 if (!map->CanTransition()) return;
663 ASSERT(!info_->IsStub());
664 stability_dependencies_.insert(map);
667 Zone* zone() const { return info_->zone(); }
669 Handle<Code> Codegen();
671 void set_allocated_double_registers(BitVector* allocated_registers);
672 BitVector* allocated_double_registers() {
673 return allocated_double_registers_;
677 LChunk(CompilationInfo* info, HGraph* graph);
679 int spill_slot_count_;
682 typedef std::less<Handle<Map> > MapLess;
683 typedef zone_allocator<Handle<Map> > MapAllocator;
684 typedef std::set<Handle<Map>, MapLess, MapAllocator> MapSet;
686 void CommitDependencies(Handle<Code> code) const;
688 CompilationInfo* info_;
689 HGraph* const graph_;
690 BitVector* allocated_double_registers_;
691 ZoneList<LInstruction*> instructions_;
692 ZoneList<LPointerMap*> pointer_maps_;
693 ZoneList<Handle<JSFunction> > inlined_closures_;
694 MapSet deprecation_dependencies_;
695 MapSet stability_dependencies_;
699 class LChunkBuilderBase BASE_EMBEDDED {
701 explicit LChunkBuilderBase(Zone* zone)
702 : argument_count_(0),
705 virtual ~LChunkBuilderBase() { }
708 // An input operand in register, stack slot or a constant operand.
709 // Will not be moved to a register even if one is freely available.
710 virtual MUST_USE_RESULT LOperand* UseAny(HValue* value) = 0;
712 LEnvironment* CreateEnvironment(HEnvironment* hydrogen_env,
713 int* argument_index_accumulator,
714 ZoneList<HValue*>* objects_to_materialize);
715 void AddObjectToMaterialize(HValue* value,
716 ZoneList<HValue*>* objects_to_materialize,
717 LEnvironment* result);
719 Zone* zone() const { return zone_; }
728 int StackSlotOffset(int index);
730 enum NumberUntagDMode {
731 NUMBER_CANDIDATE_IS_SMI,
732 NUMBER_CANDIDATE_IS_ANY_TAGGED
736 class LPhase : public CompilationPhase {
738 LPhase(const char* name, LChunk* chunk)
739 : CompilationPhase(name, chunk->info()),
746 DISALLOW_COPY_AND_ASSIGN(LPhase);
750 } } // namespace v8::internal
752 #endif // V8_LITHIUM_H_