[Intepreter] Addition of BytecodeArrayBuilder and accumulator based bytecodes.

src/interpreter/bytecode-array-builder.h

+// 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_BYTECODE_ARRAY_BUILDER_H_
+#define V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
+
+#include <vector>
+
+#include "src/ast.h"
+#include "src/interpreter/bytecodes.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+
+namespace interpreter {
+
+class BytecodeArrayBuilder {
+ public:
+  explicit BytecodeArrayBuilder(Isolate* isolate);
+  Handle<BytecodeArray> ToBytecodeArray();
+
+  // Set number of locals required for bytecode array.
+  void set_locals_count(int number_of_locals);
+  int locals_count() const;
+
+  // Constant loads to accumulator
+  BytecodeArrayBuilder& LoadLiteral(v8::internal::Smi* value);
+  BytecodeArrayBuilder& LoadUndefined();
+  BytecodeArrayBuilder& LoadNull();
+  BytecodeArrayBuilder& LoadTheHole();
+  BytecodeArrayBuilder& LoadTrue();
+  BytecodeArrayBuilder& LoadFalse();
+
+  // Register-accumulator transfers
+  BytecodeArrayBuilder& LoadAccumulatorWithRegister(int reg);
+  BytecodeArrayBuilder& StoreAccumulatorInRegister(int reg);
+
+  // Operators
+  BytecodeArrayBuilder& BinaryOperation(Token::Value binop, int reg);
+
+  // Flow Control
+  BytecodeArrayBuilder& Return();
+
+ private:
+  static Bytecode BytecodeForBinaryOperation(Token::Value op);
+
+  void Output(Bytecode bytecode, uint8_t r0, uint8_t r1, uint8_t r2);
+  void Output(Bytecode bytecode, uint8_t r0, uint8_t r1);
+  void Output(Bytecode bytecode, uint8_t r0);
+  void Output(Bytecode bytecode);
+
+  bool OperandIsValid(Bytecode bytecode, int operand_index,
+                      uint8_t operand_value) const;
+
+  int BorrowTemporaryRegister();
+  void ReturnTemporaryRegister(int reg);
+
+  Isolate* isolate_;
+  std::vector<uint8_t> bytecodes_;
+  bool bytecode_generated_;
+
+  int local_register_count_;
+  int temporary_register_count_;
+  int temporary_register_next_;
+
+  friend class TemporaryRegisterScope;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArrayBuilder);
+};
+
+// A stack-allocated class than allows the instantiator to allocate
+// temporary registers that are cleaned up when scope is closed.
+class TemporaryRegisterScope {
+ public:
+  explicit TemporaryRegisterScope(BytecodeArrayBuilder* builder);
+  ~TemporaryRegisterScope();
+  int NewRegister();
+
+ private:
+  void* operator new(size_t size);
+  void operator delete(void* p);
+
+  BytecodeArrayBuilder* builder_;
+  int count_;
+  int register_;
+
+  DISALLOW_COPY_AND_ASSIGN(TemporaryRegisterScope);
+};
+
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_