Optimize add/set/delete operations for string keys in Maps and Sets

src/hydrogen-instructions.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_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include <iosfwd>
 
 #include "src/v8.h"
@@ skipping 6342 matching lines @@
     return HObjectAccess(kInobject, CollectionType::kNumberOfBucketsOffset,
                          Representation::Smi());
   }
 
   template <typename CollectionType>
   static HObjectAccess ForOrderedHashTableNumberOfElements() {
     return HObjectAccess(kInobject, CollectionType::kNumberOfElementsOffset,
                          Representation::Smi());
   }
 
+  template <typename CollectionType>
+  static HObjectAccess ForOrderedHashTableNumberOfDeletedElements() {
+    return HObjectAccess(kInobject,
+                         CollectionType::kNumberOfDeletedElementsOffset,
+                         Representation::Smi());
+  }
+
   inline bool Equals(HObjectAccess that) const {
     return value_ == that.value_;  // portion and offset must match
   }
 
  protected:
   void SetGVNFlags(HValue *instr, PropertyAccessType access_type);
 
  private:
   // internal use only; different parts of an object or array
   enum Portion {
@@ skipping 1627 matching lines @@
 };
 
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_