[Interpreter] Bytecodes for exchanging registers.

src/compiler/interpreter-assembler.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_COMPILER_INTERPRETER_ASSEMBLER_H_
 #define V8_COMPILER_INTERPRETER_ASSEMBLER_H_
 
 // Clients of this interface shouldn't depend on lots of compiler internals.
 // Do not include anything from src/compiler here!
 #include "src/allocation.h"
@@ skipping 163 matching lines @@
   void CallPrologue();
   void CallEpilogue();
 
   // Returns the offset of register |index| relative to RegisterFilePointer().
   Node* RegisterFrameOffset(Node* index);
 
   Node* SmiShiftBitsConstant();
   Node* BytecodeOperand(int operand_index);
   Node* BytecodeOperandSignExtended(int operand_index);
   Node* BytecodeOperandShort(int operand_index);
+  Node* BytecodeOperandShortSignExtended(int operand_index);
 
   Node* CallN(CallDescriptor* descriptor, Node* code_target, Node** args);
   Node* CallIC(CallInterfaceDescriptor descriptor, Node* target, Node** args);
 
   // Returns BytecodeOffset() advanced by delta bytecodes. Note: this does not
   // update BytecodeOffset() itself.
   Node* Advance(int delta);
   Node* Advance(Node* delta);
 
   // Starts next instruction dispatch at |new_bytecode_offset|.
@@ skipping 16 matching lines @@
   bool code_generated_;
 
   DISALLOW_COPY_AND_ASSIGN(InterpreterAssembler);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INTERPRETER_ASSEMBLER_H_