| // Copyright 2015 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_INTERPRETER_CONSTANT_ARRAY_BUILDER_H_ |
| #define V8_INTERPRETER_CONSTANT_ARRAY_BUILDER_H_ |
| |
| #include "src/ast/ast-value-factory.h" |
| #include "src/globals.h" |
| #include "src/identity-map.h" |
| #include "src/interpreter/bytecodes.h" |
| #include "src/zone/zone-containers.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class Isolate; |
| class AstRawString; |
| class AstValue; |
| |
| namespace interpreter { |
| |
| // Constant array entries that represent singletons. |
| #define SINGLETON_CONSTANT_ENTRY_TYPES(V) \ |
| V(NaN, nan_value) \ |
| V(IteratorSymbol, iterator_symbol) \ |
| V(AsyncIteratorSymbol, async_iterator_symbol) \ |
| V(HomeObjectSymbol, home_object_symbol) \ |
| V(EmptyFixedArray, empty_fixed_array) \ |
| V(ClassFieldsSymbol, class_fields_symbol) |
| |
| // A helper class for constructing constant arrays for the |
| // interpreter. Each instance of this class is intended to be used to |
| // generate exactly one FixedArray of constants via the ToFixedArray |
| // method. |
| class V8_EXPORT_PRIVATE ConstantArrayBuilder final BASE_EMBEDDED { |
| public: |
| // Capacity of the 8-bit operand slice. |
| static const size_t k8BitCapacity = 1u << kBitsPerByte; |
| |
| // Capacity of the 16-bit operand slice. |
| static const size_t k16BitCapacity = (1u << 2 * kBitsPerByte) - k8BitCapacity; |
| |
| // Capacity of the 32-bit operand slice. |
| static const size_t k32BitCapacity = |
| kMaxUInt32 - k16BitCapacity - k8BitCapacity + 1; |
| |
| ConstantArrayBuilder(Zone* zone); |
| |
| // Generate a fixed array of constant handles based on inserted objects. |
| Handle<FixedArray> ToFixedArray(Isolate* isolate); |
| |
| // Returns the object, as a handle in |isolate|, that is in the constant pool |
| // array at index |index|. Returns null if there is no handle at this index. |
| // Only expected to be used in tests. |
| MaybeHandle<Object> At(size_t index, Isolate* isolate) const; |
| |
| // Returns the number of elements in the array. |
| size_t size() const; |
| |
| // Insert an object into the constants array if it is not already present. |
| // Returns the array index associated with the object. |
| size_t Insert(Smi* smi); |
| size_t Insert(double number); |
| size_t Insert(const AstRawString* raw_string); |
| size_t Insert(AstBigInt bigint); |
| size_t Insert(const Scope* scope); |
| #define INSERT_ENTRY(NAME, ...) size_t Insert##NAME(); |
| SINGLETON_CONSTANT_ENTRY_TYPES(INSERT_ENTRY) |
| #undef INSERT_ENTRY |
| |
| // Inserts an empty entry and returns the array index associated with the |
| // reservation. The entry's handle value can be inserted by calling |
| // SetDeferredAt(). |
| size_t InsertDeferred(); |
| |
| // Inserts |size| consecutive empty entries and returns the array index |
| // associated with the first reservation. Each entry's Smi value can be |
| // inserted by calling SetJumpTableSmi(). |
| size_t InsertJumpTable(size_t size); |
| |
| // Sets the deferred value at |index| to |object|. |
| void SetDeferredAt(size_t index, Handle<Object> object); |
| |
| // Sets the jump table entry at |index| to |smi|. Note that |index| is the |
| // constant pool index, not the switch case value. |
| void SetJumpTableSmi(size_t index, Smi* smi); |
| |
| // Creates a reserved entry in the constant pool and returns |
| // the size of the operand that'll be required to hold the entry |
| // when committed. |
| OperandSize CreateReservedEntry(); |
| |
| // Commit reserved entry and returns the constant pool index for the |
| // SMI value. |
| size_t CommitReservedEntry(OperandSize operand_size, Smi* value); |
| |
| // Discards constant pool reservation. |
| void DiscardReservedEntry(OperandSize operand_size); |
| |
| private: |
| typedef uint32_t index_t; |
| |
| struct ConstantArraySlice; |
| |
| class Entry { |
| private: |
| enum class Tag : uint8_t; |
| |
| public: |
| explicit Entry(Smi* smi) : smi_(smi), tag_(Tag::kSmi) {} |
| explicit Entry(double heap_number) |
| : heap_number_(heap_number), tag_(Tag::kHeapNumber) {} |
| explicit Entry(const AstRawString* raw_string) |
| : raw_string_(raw_string), tag_(Tag::kRawString) {} |
| explicit Entry(AstBigInt bigint) : bigint_(bigint), tag_(Tag::kBigInt) {} |
| explicit Entry(const Scope* scope) : scope_(scope), tag_(Tag::kScope) {} |
| |
| #define CONSTRUCT_ENTRY(NAME, LOWER_NAME) \ |
| static Entry NAME() { return Entry(Tag::k##NAME); } |
| SINGLETON_CONSTANT_ENTRY_TYPES(CONSTRUCT_ENTRY) |
| #undef CONSTRUCT_ENTRY |
| |
| static Entry Deferred() { return Entry(Tag::kDeferred); } |
| |
| static Entry UninitializedJumpTableSmi() { |
| return Entry(Tag::kUninitializedJumpTableSmi); |
| } |
| |
| bool IsDeferred() const { return tag_ == Tag::kDeferred; } |
| |
| bool IsJumpTableEntry() const { |
| return tag_ == Tag::kUninitializedJumpTableSmi || |
| tag_ == Tag::kJumpTableSmi; |
| } |
| |
| void SetDeferred(Handle<Object> handle) { |
| DCHECK_EQ(tag_, Tag::kDeferred); |
| tag_ = Tag::kHandle; |
| handle_ = handle; |
| } |
| |
| void SetJumpTableSmi(Smi* smi) { |
| DCHECK_EQ(tag_, Tag::kUninitializedJumpTableSmi); |
| tag_ = Tag::kJumpTableSmi; |
| smi_ = smi; |
| } |
| |
| Handle<Object> ToHandle(Isolate* isolate) const; |
| |
| private: |
| explicit Entry(Tag tag) : tag_(tag) {} |
| |
| union { |
| Handle<Object> handle_; |
| Smi* smi_; |
| double heap_number_; |
| const AstRawString* raw_string_; |
| AstBigInt bigint_; |
| const Scope* scope_; |
| }; |
| |
| enum class Tag : uint8_t { |
| kDeferred, |
| kHandle, |
| kSmi, |
| kRawString, |
| kHeapNumber, |
| kBigInt, |
| kScope, |
| kUninitializedJumpTableSmi, |
| kJumpTableSmi, |
| #define ENTRY_TAG(NAME, ...) k##NAME, |
| SINGLETON_CONSTANT_ENTRY_TYPES(ENTRY_TAG) |
| #undef ENTRY_TAG |
| } tag_; |
| |
| #if DEBUG |
| // Required by CheckAllElementsAreUnique(). |
| friend struct ConstantArraySlice; |
| #endif |
| }; |
| |
| index_t AllocateIndex(Entry constant_entry); |
| index_t AllocateIndexArray(Entry constant_entry, size_t size); |
| index_t AllocateReservedEntry(Smi* value); |
| |
| struct ConstantArraySlice final : public ZoneObject { |
| ConstantArraySlice(Zone* zone, size_t start_index, size_t capacity, |
| OperandSize operand_size); |
| void Reserve(); |
| void Unreserve(); |
| size_t Allocate(Entry entry, size_t count = 1); |
| Entry& At(size_t index); |
| const Entry& At(size_t index) const; |
| |
| #if DEBUG |
| void CheckAllElementsAreUnique(Isolate* isolate) const; |
| #endif |
| |
| inline size_t available() const { return capacity() - reserved() - size(); } |
| inline size_t reserved() const { return reserved_; } |
| inline size_t capacity() const { return capacity_; } |
| inline size_t size() const { return constants_.size(); } |
| inline size_t start_index() const { return start_index_; } |
| inline size_t max_index() const { return start_index_ + capacity() - 1; } |
| inline OperandSize operand_size() const { return operand_size_; } |
| |
| private: |
| const size_t start_index_; |
| const size_t capacity_; |
| size_t reserved_; |
| OperandSize operand_size_; |
| ZoneVector<Entry> constants_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ConstantArraySlice); |
| }; |
| |
| ConstantArraySlice* IndexToSlice(size_t index) const; |
| ConstantArraySlice* OperandSizeToSlice(OperandSize operand_size) const; |
| |
| ConstantArraySlice* idx_slice_[3]; |
| base::TemplateHashMapImpl<intptr_t, index_t, |
| base::KeyEqualityMatcher<intptr_t>, |
| ZoneAllocationPolicy> |
| constants_map_; |
| ZoneMap<Smi*, index_t> smi_map_; |
| ZoneVector<std::pair<Smi*, index_t>> smi_pairs_; |
| ZoneMap<double, index_t> heap_number_map_; |
| |
| #define SINGLETON_ENTRY_FIELD(NAME, LOWER_NAME) int LOWER_NAME##_; |
| SINGLETON_CONSTANT_ENTRY_TYPES(SINGLETON_ENTRY_FIELD) |
| #undef SINGLETON_ENTRY_FIELD |
| |
| Zone* zone_; |
| }; |
| |
| } // namespace interpreter |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_INTERPRETER_CONSTANT_ARRAY_BUILDER_H_ |