Turn StringLengthStub (used by string wrappers only) into a hydrogen stub.

src/ic.cc

 // Copyright 2012 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 518 matching lines @@
 
 MaybeObject* LoadIC::Load(Handle<Object> object,
                           Handle<String> name) {
   // If the object is undefined or null it's illegal to try to get any
   // of its properties; throw a TypeError in that case.
   if (object->IsUndefined() || object->IsNull()) {
     return TypeError("non_object_property_load", object, name);
   }
 
   if (FLAG_use_ic) {
-    // Use specialized code for getting the length of strings and
-    // string wrapper objects.  The length property of string wrapper
-    // objects is read-only and therefore always returns the length of
-    // the underlying string value.  See ECMA-262 15.5.5.1.
-    if (object->IsStringWrapper() &&
-        name->Equals(isolate()->heap()->length_string())) {
-      Handle<Code> stub;
-      if (state() == UNINITIALIZED) {
-        stub = pre_monomorphic_stub();
-      } else if (state() == PREMONOMORPHIC || state() == MONOMORPHIC) {
-        StringLengthStub string_length_stub(kind());
-        stub = string_length_stub.GetCode(isolate());
-      } else if (state() != MEGAMORPHIC) {
-        ASSERT(state() != GENERIC);
-        stub = megamorphic_stub();
-      }
-      if (!stub.is_null()) {
-        set_target(*stub);
-        if (FLAG_trace_ic) PrintF("[LoadIC : +#length /stringwrapper]\n");
-      }
-      // Get the string if we have a string wrapper object.
-      String* string = String::cast(JSValue::cast(*object)->value());
-      return Smi::FromInt(string->length());
-    }
-
     // Use specialized code for getting prototype of functions.
     if (object->IsJSFunction() &&
         name->Equals(isolate()->heap()->prototype_string()) &&
         Handle<JSFunction>::cast(object)->should_have_prototype()) {
       Handle<Code> stub;
       if (state() == UNINITIALIZED) {
         stub = pre_monomorphic_stub();
       } else if (state() == PREMONOMORPHIC) {
         FunctionPrototypeStub function_prototype_stub(kind());
         stub = function_prototype_stub.GetCode(isolate());
@@ skipping 329 matching lines @@
 Handle<Code> LoadIC::CompileHandler(LookupResult* lookup,
                                     Handle<Object> object,
                                     Handle<String> name,
                                     Handle<Object> unused,
                                     InlineCacheHolderFlag cache_holder) {
   if (object->IsString() && name->Equals(isolate()->heap()->length_string())) {
     int length_index = String::kLengthOffset / kPointerSize;
     return SimpleFieldLoad(length_index);
   }
 
+  if (object->IsStringWrapper() &&
+      name->Equals(isolate()->heap()->length_string())) {
+    if (kind() == Code::LOAD_IC) {
+      StringLengthStub string_length_stub;
+      return string_length_stub.GetCode(isolate());
+    } else {
+      KeyedStringLengthStub string_length_stub;
+      return string_length_stub.GetCode(isolate());
+    }
+  }
+
   Handle<HeapType> type = CurrentTypeOf(object, isolate());
   Handle<JSObject> holder(lookup->holder());
   LoadStubCompiler compiler(isolate(), kNoExtraICState, cache_holder, kind());
 
   switch (lookup->type()) {
     case FIELD: {
       PropertyIndex field = lookup->GetFieldIndex();
       if (object.is_identical_to(holder)) {
         return SimpleFieldLoad(field.translate(holder),
                                field.is_inobject(holder),
@@ skipping 1934 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal