Hydrogenize (and share) part of StoreTransition handler as a StoreTransitionStub.

src/code-stubs.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_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
@@ skipping 62 matching lines @@
   V(NumberToString)                         \
   V(RegExpConstructResult)                  \
   V(StoreFastElement)                       \
   V(StringAdd)                              \
   V(ToBoolean)                              \
   V(ToNumber)                               \
   V(TransitionElementsKind)                 \
   V(VectorKeyedLoad)                        \
   V(VectorLoad)                             \
   /* IC Handler stubs */                    \
-  V(ExtendStorage)                          \
   V(LoadConstant)                           \
   V(LoadField)                              \
   V(KeyedLoadSloppyArguments)               \
   V(StoreField)                             \
   V(StoreGlobal)                            \
+  V(StoreTransition)                        \
   V(StringLength)
 
 // List of code stubs only used on ARM 32 bits platforms.
 #if V8_TARGET_ARCH_ARM
 #define CODE_STUB_LIST_ARM(V) \
   V(DirectCEntry)             \
   V(WriteInt32ToHeapNumber)
 
 #else
 #define CODE_STUB_LIST_ARM(V)
@@ skipping 893 matching lines @@
   virtual Code::StubType GetStubType() { return Code::FAST; }
 
  private:
   class StoreFieldByIndexBits : public BitField<int, 0, 13> {};
   class RepresentationBits : public BitField<uint8_t, 13, 4> {};
 
   DEFINE_HANDLER_CODE_STUB(StoreField, HandlerStub);
 };
 
 
-// Extend storage is called in a store inline cache when
-// it is necessary to extend the properties array of a
-// JSObject.
-class ExtendStorageStub : public HandlerStub {
+class StoreTransitionStub : public HandlerStub {
  public:
-  ExtendStorageStub(Isolate* isolate, FieldIndex index,
-                    Representation representation)
+  enum StoreMode {
+    StoreMapOnly,
+    StoreMapAndValue,
+    ExtendStorageAndStoreMapAndValue
+  };
+
+  explicit StoreTransitionStub(Isolate* isolate) : HandlerStub(isolate) {
+    set_sub_minor_key(StoreModeBits::encode(StoreMapOnly));
+  }
+
+  StoreTransitionStub(Isolate* isolate, FieldIndex index,
+                      Representation representation, StoreMode store_mode)
       : HandlerStub(isolate) {
+    DCHECK(store_mode != StoreMapOnly);
     int property_index_key = index.GetFieldAccessStubKey();
     uint8_t repr = PropertyDetails::EncodeRepresentation(representation);
     set_sub_minor_key(StoreFieldByIndexBits::encode(property_index_key) |
-                      RepresentationBits::encode(repr));
+                      RepresentationBits::encode(repr) |
+                      StoreModeBits::encode(store_mode));
   }
 
   FieldIndex index() const {
+    DCHECK(store_mode() != StoreMapOnly);
     int property_index_key = StoreFieldByIndexBits::decode(sub_minor_key());
     return FieldIndex::FromFieldAccessStubKey(property_index_key);
   }
 
   Representation representation() {
+    DCHECK(store_mode() != StoreMapOnly);
     uint8_t repr = RepresentationBits::decode(sub_minor_key());
     return PropertyDetails::DecodeRepresentation(repr);
   }
 
+  StoreMode store_mode() const {
+    return StoreModeBits::decode(sub_minor_key());
+  }
+
   virtual CallInterfaceDescriptor GetCallInterfaceDescriptor() OVERRIDE;
 
  protected:
   virtual Code::Kind kind() const { return Code::STORE_IC; }
   virtual Code::StubType GetStubType() { return Code::FAST; }
 
  private:
   class StoreFieldByIndexBits : public BitField<int, 0, 13> {};
   class RepresentationBits : public BitField<uint8_t, 13, 4> {};
+  class StoreModeBits : public BitField<StoreMode, 17, 2> {};
 
-  DEFINE_HANDLER_CODE_STUB(ExtendStorage, HandlerStub);
+  DEFINE_HANDLER_CODE_STUB(StoreTransition, HandlerStub);
 };
 
 
 class StoreGlobalStub : public HandlerStub {
  public:
   StoreGlobalStub(Isolate* isolate, bool is_constant, bool check_global)
       : HandlerStub(isolate) {
     set_sub_minor_key(IsConstantBits::encode(is_constant) |
                       CheckGlobalBits::encode(check_global));
   }
@@ skipping 1423 matching lines @@
 
 #undef DEFINE_CALL_INTERFACE_DESCRIPTOR
 #undef DEFINE_PLATFORM_CODE_STUB
 #undef DEFINE_HANDLER_CODE_STUB
 #undef DEFINE_HYDROGEN_CODE_STUB
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_