Add inline caches for loading non-existing properties.

src/ia32/stub-cache-ia32.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 1930 matching lines @@
   __ bind(&miss);
   __ DecrementCounter(&Counters::keyed_store_field, 1);
   Handle<Code> ic(Builtins::builtin(Builtins::KeyedStoreIC_Miss));
   __ jmp(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode(transition == NULL ? FIELD : MAP_TRANSITION, name);
 }
 
 
+Object* LoadStubCompiler::CompileLoadNonExisting(JSObject* object) {
+  // ----------- S t a t e -------------
+  //  -- eax    : receiver
+  //  -- ecx    : name
+  //  -- esp[0] : return address
+  // -----------------------------------
+  Label miss;
+
+  // Check the maps of the full prototype chain.
+  JSObject* last = object;
+  while (last->GetPrototype() != Heap::null_value()) {
+    last = JSObject::cast(last->GetPrototype());
+  }
+  CheckPrototypes(object, eax, last, ebx, edx, Heap::empty_string(), &miss);
+
+  // Return undefined if maps of the full prototype chain is still the same.
+  __ mov(eax, Factory::undefined_value());
+  __ ret(0);
+
+  __ bind(&miss);
+  GenerateLoadMiss(masm(), Code::LOAD_IC);
+
+  // Return the generated code.
+  return GetCode(NON_EXISTING, Heap::empty_string());
+}
+
 
 Object* LoadStubCompiler::CompileLoadField(JSObject* object,
                                            JSObject* holder,
                                            int index,
                                            String* name) {
   // ----------- S t a t e -------------
   //  -- eax    : receiver
   //  -- ecx    : name
   //  -- esp[0] : return address
   // -----------------------------------
@@ skipping 464 matching lines @@
   __ jmp(generic_construct_stub, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal