| // 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/identity-map.h" |
| #include "src/interpreter/bytecodes.h" |
| #include "src/zone-containers.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class Isolate; |
| |
| namespace interpreter { |
| |
| // 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 ConstantArrayBuilder final BASE_EMBEDDED { |
| public: |
| // Capacity of the 8-bit operand slice. |
| static const size_t kLowCapacity = 1u << kBitsPerByte; |
| |
| // Capacity of the combined 8-bit and 16-bit operand slices. |
| static const size_t kMaxCapacity = 1u << (2 * kBitsPerByte); |
| |
| // Capacity of the 16-bit operand slice. |
| static const size_t kHighCapacity = kMaxCapacity - kLowCapacity; |
| |
| ConstantArrayBuilder(Isolate* isolate, Zone* zone); |
| |
| // Generate a fixed array of constants based on inserted objects. |
| Handle<FixedArray> ToFixedArray(); |
| |
| // Returns the object in the constant pool array that at index |
| // |index|. |
| Handle<Object> At(size_t index) 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(Handle<Object> object); |
| |
| // 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 |
| // object. |
| size_t CommitReservedEntry(OperandSize operand_size, Handle<Object> object); |
| |
| // Discards constant pool reservation. |
| void DiscardReservedEntry(OperandSize operand_size); |
| |
| private: |
| typedef uint16_t index_t; |
| |
| index_t AllocateEntry(Handle<Object> object); |
| |
| struct ConstantArraySlice final { |
| ConstantArraySlice(Zone* zone, size_t start_index, size_t capacity); |
| void Reserve(); |
| void Unreserve(); |
| size_t Allocate(Handle<Object> object); |
| Handle<Object> At(size_t index) const; |
| |
| 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_; } |
| |
| private: |
| const size_t start_index_; |
| const size_t capacity_; |
| size_t reserved_; |
| ZoneVector<Handle<Object>> constants_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ConstantArraySlice); |
| }; |
| |
| IdentityMap<index_t>* constants_map() { return &constants_map_; } |
| |
| Isolate* isolate_; |
| ConstantArraySlice idx8_slice_; |
| ConstantArraySlice idx16_slice_; |
| IdentityMap<index_t> constants_map_; |
| }; |
| |
| } // namespace interpreter |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_INTERPRETER_CONSTANT_ARRAY_BUILDER_H_ |