Generate StoreGlobal stubs with Hydrogen

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4670 matching lines @@
   // [marked_for_deoptimization]: For kind OPTIMIZED_FUNCTION tells whether
   // the code is going to be deoptimized because of dead embedded maps.
   inline bool marked_for_deoptimization();
   inline void set_marked_for_deoptimization(bool flag);
 
   bool allowed_in_shared_map_code_cache();
 
   // Get the safepoint entry for the given pc.
   SafepointEntry GetSafepointEntry(Address pc);
 
+  // Find an object in a stub with a specified map
+  Object* FindNthObject(int n, Map* match_map);
+  void ReplaceNthObject(int n, Map* match_map, Object* replace_with);

[rossberg, 2013/06/25 10:47:38]

As we discussed earlier, this seems rather fragile.  Is the plan still to have
an explicit notion of parameters eventually?

[danno, 2013/06/28 13:56:05]

Yes, I very much plan to clean this up, but it seems out of scope of this CL. It
seemed like too much prerequisite work to make this change dependent on.

+
   // Find the first map in an IC stub.
   Map* FindFirstMap();
   void FindAllMaps(MapHandleList* maps);
   void ReplaceFirstMap(Map* replace);
 
   // Find the first code in an IC stub.
   Code* FindFirstCode();
   void FindAllCode(CodeHandleList* code_list, int length);
 
   // Find the first name in an IC stub.
   Name* FindFirstName();
 
+  void ReplaceNthCell(int n, Cell* replace_with);
+
   class ExtraICStateStrictMode: public BitField<StrictModeFlag, 0, 1> {};
   class ExtraICStateKeyedAccessStoreMode:
       public BitField<KeyedAccessStoreMode, 1, 4> {};  // NOLINT
 
   class ExtraICStateStubHolder: public BitField<StubHolder, 0, 1> {};
 
   static inline StrictModeFlag GetStrictMode(ExtraICState extra_ic_state) {
     return ExtraICStateStrictMode::decode(extra_ic_state);
   }
 
@@ skipping 310 matching lines @@
     // deoptimized when the transition is replaced by a new version.
     kTransitionGroup,
     // Group of code that omit run-time prototype checks for prototypes
     // described by this map. The group is deoptimized whenever an object
     // described by this map changes shape (and transitions to a new map),
     // possibly invalidating the assumptions embedded in the code.
     kPrototypeCheckGroup,
     // Group of code that depends on elements not being added to objects with
     // this map.
     kElementsCantBeAddedGroup,
-    kGroupCount = kElementsCantBeAddedGroup + 1
+    // Group of code that depends on global property values in property cells
+    // not being changed.
+    kPropertyCellChangedGroup,
+    kGroupCount = kPropertyCellChangedGroup + 1
   };
 
   // Array for holding the index of the first code object of each group.
   // The last element stores the total number of code objects.
   class GroupStartIndexes {
    public:
     explicit GroupStartIndexes(DependentCode* entries);
     void Recompute(DependentCode* entries);
     int at(int i) { return start_indexes_[i]; }
     int number_of_entries() { return start_indexes_[kGroupCount]; }
@@ skipping 21 matching lines @@
   inline bool is_code_at(int i);
   inline Code* code_at(int i);
   inline CompilationInfo* compilation_info_at(int i);
   inline void set_object_at(int i, Object* object);
   inline Object** slot_at(int i);
   inline Object* object_at(int i);
   inline void clear_at(int i);
   inline void copy(int from, int to);
   static inline DependentCode* cast(Object* object);
 
+  static DependentCode* ForObject(Handle<HeapObject> object,
+                                  DependencyGroup group);
+
  private:
   // Make a room at the end of the given group by moving out the first
   // code objects of the subsequent groups.
   inline void ExtendGroup(DependencyGroup group);
   static const int kCodesStartIndex = kGroupCount;
 };
 
 
 // All heap objects have a Map that describes their structure.
 //  A Map contains information about:
@@ skipping 477 matching lines @@
   }
 
   // Fires when the layout of an object with a leaf map changes.
   // This includes adding transitions to the leaf map or changing
   // the descriptor array.
   inline void NotifyLeafMapLayoutChange();
 
   inline bool CanOmitPrototypeChecks();
 
   void AddDependentCompilationInfo(DependentCode::DependencyGroup group,
-                                        CompilationInfo* info);
+                                   CompilationInfo* info);
 
   void AddDependentCode(DependentCode::DependencyGroup group,
                         Handle<Code> code);
 
   bool IsMapInArrayPrototypeChain();
 
   // Dispatched behavior.
   DECLARE_PRINTER(Map)
   DECLARE_VERIFIER(Map)
 
@@ skipping 2982 matching lines @@
                               kValueOffset + kPointerSize,
                               kSize> BodyDescriptor;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
 };
 
 
 class PropertyCell: public Cell {
  public:
+  // [type]: type of the global property.
   Type* type();
   void set_type(Type* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
 
+  // [dependent_code]: dependent code that depends on the type of the global
+  // property.
+  DECL_ACCESSORS(dependent_code, DependentCode)
+
+  // Sets the value of the cell and updates the type field to be the union
+  // of the cell's current type and the value's type.
+  void set_value_infer_type(Object* value,

[rossberg, 2013/06/25 10:47:38]

This function can also trigger deopts, so I'd prefer not giving it a seemingly
innocent lower-case name.

[danno, 2013/06/28 13:56:05]

Done.

+                            WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+
   // Casting.
   static inline PropertyCell* cast(Object* obj);
 
   inline Address TypeAddress() {
     return address() + kTypeOffset;
   }
 
   // Dispatched behavior.
   DECLARE_PRINTER(PropertyCell)
   DECLARE_VERIFIER(PropertyCell)
 
   // Layout description.
   static const int kTypeOffset = kValueOffset + kPointerSize;
-  static const int kSize = kTypeOffset + kPointerSize;
+  static const int kDependentCodeOffset = kTypeOffset + kPointerSize;
+  static const int kSize = kDependentCodeOffset + kPointerSize;
 
-  typedef FixedBodyDescriptor<
-      kValueOffset,
-      kTypeOffset + kPointerSize,
-      PropertyCell::kSize> BodyDescriptor;
+  static const int kPointerFieldsBeginOffset = kValueOffset;
+  static const int kPointerFieldsEndOffset = kDependentCodeOffset;
+
+  typedef FixedBodyDescriptor<kValueOffset,
+                              kSize,
+                              kSize> BodyDescriptor;
+
+  void AddDependentCompilationInfo(CompilationInfo* info);
+
+  void AddDependentCode(Handle<Code> code);
+
+  Type* UnionType(Object* value);
 
  private:
   DECL_ACCESSORS(type_raw, Object)
   DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
 };
 
 
 // The JSProxy describes EcmaScript Harmony proxies
 class JSProxy: public JSReceiver {
  public:
@@ skipping 1121 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_