Revert of [compiler] Properly guard the speculative optimizations for instanceof.

src/crankshaft/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/crankshaft/hydrogen.h"
 
 #include <memory>
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
@@ skipping 11398 matching lines @@
           Handle<JSFunction>::cast(HConstant::cast(right)->handle(isolate()));
       // Make sure the prototype of {function} is the %FunctionPrototype%, and
       // it already has a meaningful initial map (i.e. we constructed at least
       // one instance using the constructor {function}).
       // We can only use the fast case if @@hasInstance was not used so far.
       if (function->has_initial_map() &&
           function->map()->prototype() ==
               function->native_context()->closure() &&
           !function->map()->has_non_instance_prototype() &&
           isolate()->IsHasInstanceLookupChainIntact()) {
-        // Make sure the feedback for the instanceof is still fast (i.e. the
-        // vector slot is still unintialized).
-        Handle<TypeFeedbackVector> vector(current_feedback_vector(), isolate());
-        Handle<Object> feedback(
-            vector->Get(expr->CompareOperationFeedbackSlot()), isolate());
-        if (feedback.is_identical_to(
-                TypeFeedbackVector::UninitializedSentinel(isolate()))) {
-          Handle<Map> initial_map(function->initial_map(), isolate());
-          top_info()->dependencies()->AssumeInitialMapCantChange(initial_map);
-          top_info()->dependencies()->AssumePropertyCell(
-              isolate()->factory()->has_instance_protector());
-          HInstruction* prototype =
-              Add<HConstant>(handle(initial_map->prototype(), isolate()));
-          HHasInPrototypeChainAndBranch* result =
-              New<HHasInPrototypeChainAndBranch>(left, prototype);
-          return ast_context()->ReturnControl(result, expr->id());
-        }
+        Handle<Map> initial_map(function->initial_map(), isolate());
+        top_info()->dependencies()->AssumeInitialMapCantChange(initial_map);
+        top_info()->dependencies()->AssumePropertyCell(
+            isolate()->factory()->has_instance_protector());
+        HInstruction* prototype =
+            Add<HConstant>(handle(initial_map->prototype(), isolate()));
+        HHasInPrototypeChainAndBranch* result =
+            New<HHasInPrototypeChainAndBranch>(left, prototype);
+        return ast_context()->ReturnControl(result, expr->id());
       }
     }
 
     Callable callable = CodeFactory::InstanceOf(isolate());
     HValue* stub = Add<HConstant>(callable.code());
     HValue* values[] = {context(), left, right};
     HCallWithDescriptor* result = New<HCallWithDescriptor>(
         stub, 0, callable.descriptor(), ArrayVector(values));
     result->set_type(HType::Boolean());
     return ast_context()->ReturnInstruction(result, expr->id());
@@ skipping 1848 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8