[elements, turbofan] Implement simple GrowElements

src/objects.h

 // Copyright 2015 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 <memory>
 
@@ skipping 1832 matching lines @@
 };
 
 enum class GetKeysConversion { kKeepNumbers, kConvertToString };
 
 enum class KeyCollectionMode {
   kOwnOnly = static_cast<int>(v8::KeyCollectionMode::kOwnOnly),
   kIncludePrototypes =
       static_cast<int>(v8::KeyCollectionMode::kIncludePrototypes)
 };
 
+enum class AllocationSiteUpdateMode { kUpdate, kCheckOnly };
+
 // JSReceiver includes types on which properties can be defined, i.e.,
 // JSObject and JSProxy.
 class JSReceiver: public HeapObject {
  public:
   // [properties]: Backing storage for properties.
   // properties is a FixedArray in the fast case and a Dictionary in the
   // slow case.
   DECL_ACCESSORS(properties, FixedArray)  // Get and set fast properties.
   inline void initialize_properties();
   inline bool HasFastProperties();
@@ skipping 430 matching lines @@
   // an access at key?
   bool WouldConvertToSlowElements(uint32_t index);
 
   // Computes the new capacity when expanding the elements of a JSObject.
   static uint32_t NewElementsCapacity(uint32_t old_capacity) {
     // (old_capacity + 50%) + 16
     return old_capacity + (old_capacity >> 1) + 16;
   }
 
   // These methods do not perform access checks!
-  static void UpdateAllocationSite(Handle<JSObject> object,
+  template <AllocationSiteUpdateMode update_or_check =
+                AllocationSiteUpdateMode::kUpdate>
+  static bool UpdateAllocationSite(Handle<JSObject> object,
                                    ElementsKind to_kind);
 
   // Lookup interceptors are used for handling properties controlled by host
   // objects.
   inline bool HasNamedInterceptor();
   inline bool HasIndexedInterceptor();
 
   // Support functions for v8 api (needed for correct interceptor behavior).
   MUST_USE_RESULT static Maybe<bool> HasRealNamedProperty(
       Handle<JSObject> object, Handle<Name> name);
@@ skipping 6341 matching lines @@
   inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
 
   inline ElementsKind GetElementsKind();
   inline void SetElementsKind(ElementsKind kind);
 
   inline bool CanInlineCall();
   inline void SetDoNotInlineCall();
 
   inline bool SitePointsToLiteral();
 
-  static void DigestTransitionFeedback(Handle<AllocationSite> site,
+  template <AllocationSiteUpdateMode update_or_check =
+                AllocationSiteUpdateMode::kUpdate>
+  static bool DigestTransitionFeedback(Handle<AllocationSite> site,
                                        ElementsKind to_kind);
 
   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 2497 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_