[interpreter] Add accumulator use description to bytecodes.

src/interpreter/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_INTERPRETER_INTERPRETER_ASSEMBLER_H_
 #define V8_INTERPRETER_INTERPRETER_ASSEMBLER_H_
 
 #include "src/allocation.h"
 #include "src/base/smart-pointers.h"
 #include "src/builtins.h"
@@ skipping 132 matching lines @@
     DispatchToBytecodeHandler(handler, BytecodeOffset());
   }
 
   // Dispatch bytecode as wide operand variant.
   void DispatchWide(OperandScale operand_scale);
 
   // Abort with the given bailout reason.
   void Abort(BailoutReason bailout_reason);
 
  protected:
+  Bytecode bytecode() const { return bytecode_; }
   static bool TargetSupportsUnalignedAccess();
 
  private:
+  // Returns the accumulator value without checking whether bytecode uses it.

[rmcilroy, 2016/04/05 12:59:23]

nit - mention it should only be used for passing accumulator value on dispatch
or for tracing. Also, I'd prefer if this was in a block of it's own (below these
4 methods).

[oth, 2016/04/05 14:12:10]

Done.

+  compiler::Node* GetAccumulatorUnchecked();
   // Returns a raw pointer to start of the register file on the stack.
   compiler::Node* RegisterFileRawPointer();
   // Returns a tagged pointer to the current function's BytecodeArray object.
   compiler::Node* BytecodeArrayTaggedPointer();
   // Returns the offset from the BytecodeArrayPointer of the current bytecode.
   compiler::Node* BytecodeOffset();
   // Returns a raw pointer to first entry in the interpreter dispatch table.
   compiler::Node* DispatchTableRawPointer();
 
   // Saves and restores interpreter bytecode offset to the interpreter stack
@@ skipping 44 matching lines @@
 
   // Abort operations for debug code.
   void AbortIfWordNotEqual(compiler::Node* lhs, compiler::Node* rhs,
                            BailoutReason bailout_reason);
 
   OperandScale operand_scale() const { return operand_scale_; }
 
   Bytecode bytecode_;
   OperandScale operand_scale_;
   CodeStubAssembler::Variable accumulator_;
+  AccumulatorUse accumulator_use_;
   CodeStubAssembler::Variable context_;
   CodeStubAssembler::Variable bytecode_array_;
 
   bool disable_stack_check_across_call_;
   compiler::Node* stack_pointer_before_call_;
 
   DISALLOW_COPY_AND_ASSIGN(InterpreterAssembler);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_INTERPRETER_ASSEMBLER_H_