Add a soft-deopt in keyed element access when current IC is pre-monomorphic and no type feedback wa…

src/ast.cc

Index: src/ast.cc
diff --git a/src/ast.cc b/src/ast.cc
index 0d667cc168812d0b3f487bf422f1bcf096ac4d1c..1f5886c985c682d4e1a0b8cf5360907bad44219d 100644
--- a/src/ast.cc
+++ b/src/ast.cc
@@ -139,6 +139,7 @@ Assignment::Assignment(Isolate* isolate,
       assignment_id_(GetNextId(isolate)),
       is_monomorphic_(false),
       is_uninitialized_(false),
+      is_pre_monomorphic_(false),
       store_mode_(STANDARD_STORE) { }
 
 
@@ -426,7 +427,10 @@ void Property::RecordTypeFeedback(TypeFeedbackOracle* oracle,
   is_uninitialized_ = oracle->LoadIsUninitialized(this);
   if (is_uninitialized_) return;
 
+  is_pre_monomorphic_ = oracle->LoadIsPreMonomorphic(this);
   is_monomorphic_ = oracle->LoadIsMonomorphicNormal(this);
+  ASSERT((is_pre_monomorphic_ && !is_monomorphic_) ||
+         (!is_pre_monomorphic_ && is_monomorphic_));
   receiver_types_.Clear();
   if (key()->IsPropertyName()) {
     FunctionPrototypeStub proto_stub(Code::LOAD_IC);
@@ -456,7 +460,11 @@ void Assignment::RecordTypeFeedback(TypeFeedbackOracle* oracle,
   TypeFeedbackId id = AssignmentFeedbackId();
   is_uninitialized_ = oracle->StoreIsUninitialized(id);
   if (is_uninitialized_) return;
+
+  is_pre_monomorphic_ = oracle->StoreIsPreMonomorphic(id);
   is_monomorphic_ = oracle->StoreIsMonomorphicNormal(id);
+  ASSERT((is_pre_monomorphic_ && !is_monomorphic_) ||
+         (!is_pre_monomorphic_ && is_monomorphic_));
   receiver_types_.Clear();
   if (prop->key()->IsPropertyName()) {
     Literal* lit_key = prop->key()->AsLiteral();