Replace ICStub for array.length with hydrogen stub

src/stub-cache.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 215 matching lines @@
   if (!stub.is_null()) return stub;
 
   LoadStubCompiler compiler(isolate_);
   Handle<Code> handler =
       compiler.CompileLoadField(receiver, holder, name, field);
   JSObject::UpdateMapCodeCache(stub_holder, name, handler);
   return handler;
 }
 
 
+Handle<Code> StubCache::ComputeLoadArrayLength(Handle<Name> name,

[danno, 2013/03/12 11:16:16]

Instead of adding these, how about just make CompileLoadField smarter?

+                                               Handle<JSObject> receiver,
+                                               Handle<JSObject> holder) {
+  ASSERT(name->Equals(isolate_->heap()->length_string()));
+  if (receiver.is_identical_to(holder)) {
+    FastArrayLengthStub stub(LoadStubCompiler::receiver());
+    return stub.GetCode(isolate_);
+  }
+
+  Handle<JSObject> stub_holder = StubHolder(receiver, holder);
+  Handle<Code> stub = FindStub(
+      name, stub_holder, Code::LOAD_IC, Code::CALLBACKS);
+  if (!stub.is_null()) return stub;
+
+  LoadStubCompiler ic_compiler(isolate_);
+  Handle<Code> ic = ic_compiler.CompileArrayLength(receiver, holder, name);
+  JSObject::UpdateMapCodeCache(stub_holder, name, ic);
+  return ic;
+}
+
+
 Handle<Code> StubCache::ComputeLoadCallback(
     Handle<Name> name,
     Handle<JSObject> receiver,
     Handle<JSObject> holder,
     Handle<ExecutableAccessorInfo> callback) {
   ASSERT(v8::ToCData<Address>(callback->getter()) != 0);
   Handle<JSObject> stub_holder = StubHolder(receiver, holder);
   Handle<Code> stub = FindStub(
       name, stub_holder, Code::LOAD_IC, Code::CALLBACKS);
   if (!stub.is_null()) return stub;
@@ skipping 1198 matching lines @@
 
 
 Handle<Code> BaseLoadStubCompiler::CompileLoadField(Handle<JSObject> object,
                                                     Handle<JSObject> holder,
                                                     Handle<Name> name,
                                                     PropertyIndex field) {
   Label miss;
 
   Register reg = HandlerFrontendHeader(object, receiver(), holder, name, &miss);
 
   LoadFieldStub stub(reg, field.is_inobject(holder), field.translate(holder));

[danno, 2013/03/12 11:16:16]

If you make a new method, GetLoadFieldHandler that takes the field and the name
and returns either a FastArrayLengthStub or a LoadFieldStub?

   GenerateTailCall(stub.GetCode(isolate()));
 
   __ bind(&miss);
   GenerateLoadMiss(masm(), kind());
 
   // Return the generated code.
   return GetCode(kind(), Code::FIELD, name);
 }
 
 
+Handle<Code> BaseLoadStubCompiler::CompileArrayLength(Handle<JSObject> object,
+                                                      Handle<JSObject> holder,
+                                                      Handle<Name> name) {
+  ASSERT(name->Equals(isolate()->heap()->length_string()));
+  Label miss;
+
+  Register reg = HandlerFrontendHeader(object, receiver(), holder, name, &miss);
+  FastArrayLengthStub stub(reg);
+  GenerateTailCall(stub.GetCode(isolate()));
+
+  __ bind(&miss);
+  GenerateLoadMiss(masm(), kind());
+
+  return GetCode(kind(), Code::CALLBACKS, name);
+}
+
+
 Handle<Code> BaseLoadStubCompiler::CompileLoadConstant(
     Handle<JSObject> object,
     Handle<JSObject> holder,
     Handle<Name> name,
     Handle<JSFunction> value) {
   Label success;
   HandlerFrontend(object, receiver(), holder, name, &success);
   __ bind(&success);
   GenerateLoadConstant(value);
 
@@ skipping 402 matching lines @@
           Handle<FunctionTemplateInfo>(
               FunctionTemplateInfo::cast(signature->receiver()));
     }
   }
 
   is_simple_api_call_ = true;
 }
 
 
 } }  // namespace v8::internal