Flesh out vector ic state query and set mechanisms.

test/cctest/test-feedback-vector.cc

Index: test/cctest/test-feedback-vector.cc
diff --git a/test/cctest/test-feedback-vector.cc b/test/cctest/test-feedback-vector.cc
index 28a15f2029ef2f100cb5cc5b61c035e8c372b4e5..52aaf918e5e11a52a212dbcd6a22f54843feba3a 100644
--- a/test/cctest/test-feedback-vector.cc
+++ b/test/cctest/test-feedback-vector.cc
@@ -53,6 +53,7 @@ TEST(VectorStructure) {
   }
 
   int index = vector->GetIndex(FeedbackVectorSlot(0));
+
   CHECK_EQ(TypeFeedbackVector::kReservedIndexCount + metadata_length, index);
   CHECK(FeedbackVectorSlot(0) == vector->ToSlot(index));
 
@@ -188,7 +189,7 @@ TEST(VectorICProfilerStatistics) {
   CHECK_EQ(1, feedback_vector->ic_with_type_info_count());
   CHECK_EQ(0, feedback_vector->ic_generic_count());
 
-  int ic_slot = FLAG_vector_ics ? 1 : 0;
+  int ic_slot = 0;
   CHECK(
       feedback_vector->Get(FeedbackVectorICSlot(ic_slot))->IsAllocationSite());
   heap->CollectAllGarbage(i::Heap::kNoGCFlags);
@@ -217,7 +218,7 @@ TEST(VectorCallICStates) {
   // There should be one IC.
   Handle<TypeFeedbackVector> feedback_vector =
       Handle<TypeFeedbackVector>(f->shared()->feedback_vector(), isolate);
-  FeedbackVectorICSlot slot(FLAG_vector_ics ? 1 : 0);
+  FeedbackVectorICSlot slot(0);
   CallICNexus nexus(feedback_vector, slot);
   CHECK_EQ(MONOMORPHIC, nexus.StateFromFeedback());
   // CallIC doesn't return map feedback.
@@ -239,4 +240,58 @@ TEST(VectorCallICStates) {
   heap->CollectAllGarbage(i::Heap::kNoGCFlags);
   CHECK_EQ(MONOMORPHIC, nexus.StateFromFeedback());
 }
+
+
+TEST(VectorLoadICStates) {
+  if (i::FLAG_always_opt || !i::FLAG_vector_ics) return;
+  CcTest::InitializeVM();
+  LocalContext context;
+  v8::HandleScope scope(context->GetIsolate());
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+
+  // Make sure function f has a call that uses a type feedback slot.
+  CompileRun(
+      "var o = { foo: 3 };"
+      "function f(a) { return a.foo; } f(o);");
+  Handle<JSFunction> f = v8::Utils::OpenHandle(
+      *v8::Handle<v8::Function>::Cast(CcTest::global()->Get(v8_str("f"))));
+  // There should be one IC.
+  Handle<TypeFeedbackVector> feedback_vector =
+      Handle<TypeFeedbackVector>(f->shared()->feedback_vector(), isolate);
+  FeedbackVectorICSlot slot(0);
+  LoadICNexus nexus(feedback_vector, slot);
+  CHECK_EQ(PREMONOMORPHIC, nexus.StateFromFeedback());
+
+  CompileRun("f(o)");
+  CHECK_EQ(MONOMORPHIC, nexus.StateFromFeedback());
+  // Verify that the monomorphic map is the one we expect.
+  Handle<JSObject> o = v8::Utils::OpenHandle(
+      *v8::Handle<v8::Object>::Cast(CcTest::global()->Get(v8_str("o"))));
+  CHECK_EQ(o->map(), nexus.FindFirstMap());
+
+  // Now go polymorphic.
+  CompileRun("f({ blarg: 3, foo: 2 })");
+  CHECK_EQ(POLYMORPHIC, nexus.StateFromFeedback());
+
+  CompileRun(
+      "delete o.foo;"
+      "f(o)");
+  CHECK_EQ(POLYMORPHIC, nexus.StateFromFeedback());
+
+  CompileRun("f({ blarg: 3, torino: 10, foo: 2 })");
+  CHECK_EQ(POLYMORPHIC, nexus.StateFromFeedback());
+  MapHandleList maps;
+  nexus.FindAllMaps(&maps);
+  CHECK_EQ(4, maps.length());
+
+  // Finally driven megamorphic.
+  CompileRun("f({ blarg: 3, gran: 3, torino: 10, foo: 2 })");
+  CHECK_EQ(MEGAMORPHIC, nexus.StateFromFeedback());
+  CHECK_EQ(NULL, nexus.FindFirstMap());
+
+  // After a collection, state should be reset to PREMONOMORPHIC.
+  heap->CollectAllGarbage(i::Heap::kNoGCFlags);
+  CHECK_EQ(PREMONOMORPHIC, nexus.StateFromFeedback());
+}
 }