[interpreter] Bytecode register optimizer.

src/interpreter/bytecode-pipeline.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_PIPELINE_H_
 #define V8_INTERPRETER_BYTECODE_PIPELINE_H_
 
 #include "src/interpreter/bytecode-register-allocator.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/zone-containers.h"
@@ skipping 93 matching lines @@
 
   uint32_t operand(int i) const {
     DCHECK_LT(i, operand_count());
     return operands_[i];
   }
   uint32_t* operands() { return operands_; }
   const uint32_t* operands() const { return operands_; }
 
   int operand_count() const { return Bytecodes::NumberOfOperands(bytecode_); }
   OperandScale operand_scale() const { return operand_scale_; }
+  void set_operand_scale(OperandScale operand_scale) {
+    operand_scale_ = operand_scale;
+  }
 
   const BytecodeSourceInfo& source_info() const { return source_info_; }
   BytecodeSourceInfo& source_info() { return source_info_; }
 
   bool operator==(const BytecodeNode& other) const;
   bool operator!=(const BytecodeNode& other) const { return !(*this == other); }
 
  private:
   static const int kInvalidPosition = kMinInt;
   static const size_t kMaxOperands = 4;
 
   Bytecode bytecode_;
   uint32_t operands_[kMaxOperands];
   OperandScale operand_scale_;
   BytecodeSourceInfo source_info_;
 };
 
 std::ostream& operator<<(std::ostream& os, const BytecodeSourceInfo& info);
 std::ostream& operator<<(std::ostream& os, const BytecodeNode& node);
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_PIPELINE_H_