Replace ICStub for array.length with hydrogen stub

src/stub-cache.cc

Index: src/stub-cache.cc
diff --git a/src/stub-cache.cc b/src/stub-cache.cc
index ac94fffebd0553b34a3fdf315d1220506178b833..bda659048142d9275d1ff1f10cd61bafe1f52518 100644
--- a/src/stub-cache.cc
+++ b/src/stub-cache.cc
@@ -233,6 +233,27 @@ Handle<Code> StubCache::ComputeLoadField(Handle<Name> name,
 }
 
 
+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,
@@ -1462,6 +1483,23 @@ Handle<Code> BaseLoadStubCompiler::CompileLoadField(Handle<JSObject> object,
 }
 
 
+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,