More x64 work.

src/x64/lithium-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 128 matching lines @@
   V(Return)                                     \
   V(ShiftI)                                     \
   V(SmiTag)                                     \
   V(SmiUntag)                                   \
   V(StackCheck)                                 \
   V(StoreGlobal)                                \
   V(StoreKeyedFastElement)                      \
   V(StoreKeyedGeneric)                          \
   V(StoreNamedField)                            \
   V(StoreNamedGeneric)                          \
+  V(StringLength)                               \
   V(SubI)                                       \
   V(TaggedToI)                                  \
   V(Throw)                                      \
   V(Typeof)                                     \
   V(TypeofIs)                                   \
   V(TypeofIsAndBranch)                          \
   V(IsConstructCall)                            \
   V(IsConstructCallAndBranch)                   \
   V(UnaryMathOperation)                         \
   V(UnknownOSRValue)                            \
@@ skipping 1384 matching lines @@
 
 class LStoreKeyedGeneric: public LStoreKeyed {
  public:
   LStoreKeyedGeneric(LOperand* obj, LOperand* key, LOperand* val)
       : LStoreKeyed(obj, key, val) { }
 
   DECLARE_CONCRETE_INSTRUCTION(StoreKeyedGeneric, "store-keyed-generic")
 };
 
 
+class LStringLength: public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LStringLength(LOperand* string) {
+    inputs_[0] = string;
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(StringLength, "string-length")
+  DECLARE_HYDROGEN_ACCESSOR(StringLength)
+
+  LOperand* string() { return inputs_[0]; }
+};
+
+
 class LCheckFunction: public LTemplateInstruction<0, 1, 0> {
  public:
   explicit LCheckFunction(LOperand* value) {
     inputs_[0] = value;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(CheckFunction, "check-function")
   DECLARE_HYDROGEN_ACCESSOR(CheckFunction)
 };
 
@@ skipping 400 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_