Speed up comparison with a constant.

src/x64/lithium-codegen-x64.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 59 matching lines @@
   CompilationInfo* info() const { return info_; }
   Isolate* isolate() const { return info_->isolate(); }
   Factory* factory() const { return isolate()->factory(); }
   Heap* heap() const { return isolate()->heap(); }
 
   // Support for converting LOperands to assembler types.
   Register ToRegister(LOperand* op) const;
   XMMRegister ToDoubleRegister(LOperand* op) const;
   bool IsInteger32Constant(LConstantOperand* op) const;
   int ToInteger32(LConstantOperand* op) const;
+  double ToDouble(LConstantOperand* op) const;
   bool IsTaggedConstant(LConstantOperand* op) const;
   Handle<Object> ToHandle(LConstantOperand* op) const;
   Operand ToOperand(LOperand* op) const;
 
   // Try to generate code for the entire chunk, but it may fail if the
   // chunk contains constructs we cannot handle. Returns true if the
   // code generation attempt succeeded.
   bool GenerateCode();
 
   // Finish the code by setting stack height, safepoint, and bailout
@@ skipping 153 matching lines @@
                                     int arguments,
                                     int deoptimization_index);
   void RecordPosition(int position);
   int LastSafepointEnd() {
     return static_cast<int>(safepoints_.GetPcAfterGap());
   }
 
   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
   void EmitGoto(int block);
   void EmitBranch(int left_block, int right_block, Condition cc);
-  void EmitCmpI(LOperand* left, LOperand* right);
   void EmitNumberUntagD(Register input,
                         XMMRegister result,
                         bool deoptimize_on_undefined,
                         LEnvironment* env);
 
   // Emits optimized code for typeof x == "y".  Modifies input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.
   Condition EmitTypeofIs(Label* true_label,
                          Label* false_label,
@@ skipping 106 matching lines @@
   LCodeGen* codegen_;
   Label entry_;
   Label exit_;
   Label* external_exit_;
   int instruction_index_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_LITHIUM_CODEGEN_X64_H_