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

src/type-info.cc

 // Copyright 2012 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/ast.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/ic/ic.h"
@@ skipping 248 matching lines @@
                                                SmallMapList* receiver_types) {
   receiver_types->Clear();
   Code::Flags flags = Code::ComputeHandlerFlags(Code::LOAD_IC);
   CollectReceiverTypes(id, name, flags, receiver_types);
 }
 
 
 void TypeFeedbackOracle::KeyedPropertyReceiverTypes(
     TypeFeedbackId id, SmallMapList* receiver_types, bool* is_string) {
   receiver_types->Clear();
-  *is_string = false;
-  if (LoadIsBuiltin(id, Builtins::kKeyedLoadIC_String)) {
-    *is_string = true;
-  } else {
-    CollectReceiverTypes(id, receiver_types);
+  CollectReceiverTypes(id, receiver_types);
+
+  // Are all the receiver maps string maps?
+  bool all_strings = receiver_types->length() > 0;
+  for (int i = 0; i < receiver_types->length(); i++) {
+    all_strings &= receiver_types->at(i)->IsStringMap();
   }
+  *is_string = all_strings;
 }
 
 
 void TypeFeedbackOracle::AssignmentReceiverTypes(
     TypeFeedbackId id, Handle<String> name, SmallMapList* receiver_types) {
   receiver_types->Clear();
   Code::Flags flags = Code::ComputeHandlerFlags(Code::STORE_IC);
   CollectReceiverTypes(id, name, flags, receiver_types);
 }
 
@@ skipping 176 matching lines @@
          UnseededNumberDictionary::kNotFound);
   // Dictionary has been allocated with sufficient size for all elements.
   DisallowHeapAllocation no_need_to_resize_dictionary;
   HandleScope scope(isolate());
   USE(UnseededNumberDictionary::AtNumberPut(
       dictionary_, IdToKey(ast_id), handle(target, isolate())));
 }
 
 
 } }  // namespace v8::internal