[Intepreter] Extend and move Register class.

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/frames.h"
 #include "src/identity-map.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/zone.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 
 class Isolate;
 
@@ skipping 29 matching lines @@
   BytecodeArrayBuilder& LoadAccumulatorWithRegister(Register reg);
   BytecodeArrayBuilder& StoreAccumulatorInRegister(Register reg);
 
   // Operators.
   BytecodeArrayBuilder& BinaryOperation(Token::Value binop, Register reg);
 
   // Flow Control.
   BytecodeArrayBuilder& Return();
 
  private:
-  static const int kLastParamRegisterIndex =
-      -InterpreterFrameConstants::kLastParamFromRegisterPointer / kPointerSize;
-
   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;
 
@@ skipping 13 matching lines @@
   int local_register_count_;
   int temporary_register_count_;
   int temporary_register_next_;
 
   friend class TemporaryRegisterScope;
   DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArrayBuilder);
 };
 
 // An interpreter register which is located in the function's register file
 // in its stack-frame.
 class Register {

[rmcilroy, 2015/09/02 11:42:41]

Would it be simpler just to move the Register class over to bytecodes.h?
(Genuine question)

[oth, 2015/09/02 14:02:19]

Done.

  public:
   static const int kMaxRegisterIndex = 128;
   static const int kMinRegisterIndex = -127;
 
   explicit Register(int index) : index_(index) {
     DCHECK_LE(index_, kMaxRegisterIndex);
     DCHECK_GE(index_, kMinRegisterIndex);
   }
 
   int index() { return index_; }
 
-  uint8_t ToOperand() { return static_cast<uint8_t>(-index_); }
+  uint8_t ToOperand() { return Bytecodes::RegisterIndexToOperand(index_); }
   static Register FromOperand(uint8_t operand) {
-    return Register(-static_cast<int8_t>(operand));
+    return Register(Bytecodes::RegisterIndexFromOperand(operand));
   }
 
  private:
   void* operator new(size_t size);
   void operator delete(void* p);
 
   int index_;
 };
 
 // A stack-allocated class than allows the instantiator to allocate
@@ skipping 14 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(TemporaryRegisterScope);
 };
 
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_