Support StringLength in hydrogen (similar to ArrayLength).

src/ic.cc

 // Copyright 2006-2009 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 804 matching lines @@
 MaybeObject* LoadIC::Load(State state,
                           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) {
+    Code* non_monomorphic_stub =
+        (state == UNINITIALIZED) ? pre_monomorphic_stub() : megamorphic_stub();
+
     // 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->IsString() || object->IsStringWrapper()) &&
         name->Equals(Heap::length_symbol())) {
       HandleScope scope;
+#ifdef DEBUG
+      if (FLAG_trace_ic) PrintF("[LoadIC : +#length /string]\n");
+#endif
+      if (state == PREMONOMORPHIC) {
+        if (object->IsString()) {
+          Map* map = HeapObject::cast(*object)->map();
+          const int offset = String::kLengthOffset;
+          PatchInlinedLoad(address(), map, offset);
+          set_target(Builtins::builtin(Builtins::LoadIC_StringLength));
+        } else {
+          set_target(Builtins::builtin(Builtins::LoadIC_StringWrapperLength));
+        }
+      } else if (state == MONOMORPHIC && object->IsStringWrapper()) {
+        set_target(Builtins::builtin(Builtins::LoadIC_StringWrapperLength));
+      } else {
+        set_target(non_monomorphic_stub);
+      }
       // Get the string if we have a string wrapper object.
       if (object->IsJSValue()) {
         object = Handle<Object>(Handle<JSValue>::cast(object)->value());
       }
-#ifdef DEBUG
-      if (FLAG_trace_ic) PrintF("[LoadIC : +#length /string]\n");
-#endif
-      Map* map = HeapObject::cast(*object)->map();
-      if (object->IsString()) {
-        const int offset = String::kLengthOffset;
-        PatchInlinedLoad(address(), map, offset);
-      }
-
-      Code* target = NULL;
-      target = Builtins::builtin(Builtins::LoadIC_StringLength);
-      set_target(target);
       return Smi::FromInt(String::cast(*object)->length());
     }
 
     // Use specialized code for getting the length of arrays.
     if (object->IsJSArray() && name->Equals(Heap::length_symbol())) {
 #ifdef DEBUG
       if (FLAG_trace_ic) PrintF("[LoadIC : +#length /array]\n");
 #endif
-      Map* map = HeapObject::cast(*object)->map();
-      const int offset = JSArray::kLengthOffset;
-      PatchInlinedLoad(address(), map, offset);
-
-      Code* target = Builtins::builtin(Builtins::LoadIC_ArrayLength);
-      set_target(target);
+      if (state == PREMONOMORPHIC) {
+        Map* map = HeapObject::cast(*object)->map();
+        const int offset = JSArray::kLengthOffset;
+        PatchInlinedLoad(address(), map, offset);
+        set_target(Builtins::builtin(Builtins::LoadIC_ArrayLength));
+      } else {
+        set_target(non_monomorphic_stub);
+      }
       return JSArray::cast(*object)->length();
     }
 
     // Use specialized code for getting prototype of functions.
     if (object->IsJSFunction() && name->Equals(Heap::prototype_symbol()) &&
         JSFunction::cast(*object)->should_have_prototype()) {
 #ifdef DEBUG
       if (FLAG_trace_ic) PrintF("[LoadIC : +#prototype /function]\n");
 #endif
-      Code* target = Builtins::builtin(Builtins::LoadIC_FunctionPrototype);
-      set_target(target);
+      if (state == PREMONOMORPHIC) {
+        set_target(Builtins::builtin(Builtins::LoadIC_FunctionPrototype));
+      } else {
+        set_target(non_monomorphic_stub);
+      }
       return Accessors::FunctionGetPrototype(*object, 0);
     }
   }
 
   // Check if the name is trivially convertible to an index and get
   // the element if so.
   uint32_t index;
   if (name->AsArrayIndex(&index)) return object->GetElement(index);
 
   // Named lookup in the object.
@@ skipping 1347 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal