VectorICs: use a vector slot to aid in array literal processing.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 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/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 314 matching lines @@
     node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
     ReplaceWithStubCall(node, callable, flags);
   }
 }
 
 
 void JSGenericLowering::LowerJSStoreProperty(Node* node) {
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
   const StorePropertyParameters& p = StorePropertyParametersOf(node->op());
   LanguageMode language_mode = p.language_mode();
-  // We have a special case where we do keyed stores but don't have a type
-  // feedback vector slot allocated to support it. In this case, install
-  // the megamorphic keyed store stub which needs neither vector nor slot.
-  bool use_vector_slot = FLAG_vector_stores && p.feedback().index() != -1;
   Callable callable = CodeFactory::KeyedStoreICInOptimizedCode(
-      isolate(), language_mode,
-      (use_vector_slot || !FLAG_vector_stores) ? UNINITIALIZED : MEGAMORPHIC);
-  if (use_vector_slot) {
+      isolate(), language_mode, UNINITIALIZED);
+  if (FLAG_vector_stores) {
+    DCHECK(p.feedback().index() != -1);
     node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
   } else {
     node->RemoveInput(3);
   }
   ReplaceWithStubCall(node, callable,
                       CallDescriptor::kPatchableCallSite | flags);
 }
 
 
 void JSGenericLowering::LowerJSStoreNamed(Node* node) {
@@ skipping 501 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8