Hydrogen should recognize literal smi arrays as fast literals.

src/objects.h

 // Copyright 2012 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 8335 matching lines @@
   bool SitePointsToLiteral() {
     // If transition_info is a smi, then it represents an ElementsKind
     // for a constructed array. Otherwise, it must be a boilerplate
     // for an object or array literal.
     return transition_info()->IsJSArray() || transition_info()->IsJSObject();
   }
 
   static void DigestTransitionFeedback(Handle<AllocationSite> site,
                                        ElementsKind to_kind);
 
-  enum Reason {
-    TENURING,
-    TRANSITIONS
-  };
+  static void RegisterForDeoptOnTenureChange(Handle<AllocationSite> site,
+                                             CompilationInfo* info);
 
-  static void AddDependentCompilationInfo(Handle<AllocationSite> site,
-                                          Reason reason,
-                                          CompilationInfo* info);
+  static void RegisterForDeoptOnTransitionChange(Handle<AllocationSite> site,
+                                                 CompilationInfo* info);
 
   DECLARE_PRINTER(AllocationSite)
   DECLARE_VERIFIER(AllocationSite)
 
   DECLARE_CAST(AllocationSite)
   static inline AllocationSiteMode GetMode(
       ElementsKind boilerplate_elements_kind);
   static inline AllocationSiteMode GetMode(ElementsKind from, ElementsKind to);
   static inline bool CanTrack(InstanceType type);
 
@@ skipping 11 matching lines @@
   // field.
   static const int kPointerFieldsBeginOffset = kTransitionInfoOffset;
   static const int kPointerFieldsEndOffset = kDependentCodeOffset;
 
   // For other visitors, use the fixed body descriptor below.
   typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
                               kDependentCodeOffset + kPointerSize,
                               kSize> BodyDescriptor;
 
  private:
-  inline DependentCode::DependencyGroup ToDependencyGroup(Reason reason);
+  static void AddDependentCompilationInfo(Handle<AllocationSite> site,
+                                          DependentCode::DependencyGroup group,
+                                          CompilationInfo* info);
+
   bool PretenuringDecisionMade() {
     return pretenure_decision() != kUndecided;
   }
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
 };
 
 
 class AllocationMemento: public Struct {
  public:
@@ skipping 2561 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_