Eliminate special keyed load string stub in favor of uniform handlers.

src/ic/ic-compiler.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 
 #include "src/ic/handler-compiler.h"
 #include "src/ic/ic-inl.h"
 #include "src/ic/ic-compiler.h"
 
@@ skipping 78 matching lines @@
   Code::Flags flags = Code::ComputeMonomorphicFlags(Code::KEYED_LOAD_IC);
   Handle<Name> name = isolate->factory()->KeyedLoadMonomorphic_string();
 
   Handle<Object> probe(receiver_map->FindInCodeCache(*name, flags), isolate);
   if (probe->IsCode()) return Handle<Code>::cast(probe);
 
   ElementsKind elements_kind = receiver_map->elements_kind();
   Handle<Code> stub;
   if (receiver_map->has_indexed_interceptor()) {
     stub = LoadIndexedInterceptorStub(isolate).GetCode();
+  } else if (receiver_map->IsStringMap()) {
+    // We have a string.
+    stub = LoadIndexedStringStub(isolate).GetCode();
   } else if (receiver_map->has_sloppy_arguments_elements()) {
     stub = KeyedLoadSloppyArgumentsStub(isolate).GetCode();
   } else if (receiver_map->has_fast_elements() ||
              receiver_map->has_external_array_elements() ||
              receiver_map->has_fixed_typed_array_elements()) {
     stub = LoadFastElementStub(isolate,
                                receiver_map->instance_type() == JS_ARRAY_TYPE,
                                elements_kind).GetCode();
   } else {
     stub = LoadDictionaryElementStub(isolate).GetCode();
@@ skipping 329 matching lines @@
 
   TailCallBuiltin(masm(), Builtins::kKeyedStoreIC_Miss);
 
   return GetCode(kind(), Code::NORMAL, factory()->empty_string());
 }
 
 
 #undef __
 }
 }  // namespace v8::internal