--- a/src/hotspot/share/oops/klass.hpp	Mon Jun 25 12:44:52 2018 +0200
+++ b/src/hotspot/share/oops/klass.hpp	Sat May 26 06:59:49 2018 +0200
@@ -26,7 +26,6 @@
 #define SHARE_VM_OOPS_KLASS_HPP
 
 #include "classfile/classLoaderData.hpp"
-#include "gc/shared/specialized_oop_closures.hpp"
 #include "memory/iterator.hpp"
 #include "memory/memRegion.hpp"
 #include "oops/metadata.hpp"
@@ -38,6 +37,18 @@
 #include "jfr/support/jfrTraceIdExtension.hpp"
 #endif
 
+// Klass IDs for all subclasses of Klass
+enum KlassID {
+  InstanceKlassID,
+  InstanceRefKlassID,
+  InstanceMirrorKlassID,
+  InstanceClassLoaderKlassID,
+  TypeArrayKlassID,
+  ObjArrayKlassID
+};
+
+const uint KLASS_ID_COUNT = 6;
+
 //
 // A Klass provides:
 //  1: language level class object (method dictionary etc.)
@@ -103,6 +114,9 @@
   // because it is frequently queried.
   jint        _layout_helper;
 
+  // Klass identifier used to implement devirtualized oop closure dispatching.
+  const KlassID _id;
+
   // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
   // and _primary_supers all help make fast subtype checks.  See big discussion
   // in doc/server_compiler/checktype.txt
@@ -173,11 +187,14 @@
 protected:
 
   // Constructor
-  Klass();
+  Klass(KlassID id);
+  Klass() : _id(KlassID(-1)) { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }
 
   void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw();
 
  public:
+  int id() { return _id; }
+
   enum DefaultsLookupMode { find_defaults, skip_defaults };
   enum OverpassLookupMode { find_overpass, skip_overpass };
   enum StaticLookupMode   { find_static,   skip_static };
@@ -660,24 +677,6 @@
   virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0;
 #endif
 
-  // Iterators specialized to particular subtypes
-  // of ExtendedOopClosure, to avoid closure virtual calls.
-#define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                                           \
-  virtual void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) = 0;                        \
-  /* Iterates "closure" over all the oops in "obj" (of type "this") within "mr". */                     \
-  virtual void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) = 0;
-
-  ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
-  ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL)
-
-#if INCLUDE_OOP_OOP_ITERATE_BACKWARDS
-#define Klass_OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix)                     \
-  virtual void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) = 0;
-
-  ALL_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
-  ALL_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL_BACKWARDS)
-#endif
-
   virtual void array_klasses_do(void f(Klass* k)) {}
 
   // Return self, except for abstract classes with exactly 1
@@ -725,44 +724,4 @@
   static Klass* decode_klass(narrowKlass v);
 };
 
-// Helper to convert the oop iterate macro suffixes into bool values that can be used by template functions.
-#define nvs_nv_to_bool true
-#define nvs_v_to_bool  false
-#define nvs_to_bool(nv_suffix) nvs##nv_suffix##_to_bool
-
-// Oop iteration macros for declarations.
-// Used to generate declarations in the *Klass header files.
-
-#define OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                                    \
-  void oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure);                        \
-  void oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr);
-
-#if INCLUDE_OOP_OOP_ITERATE_BACKWARDS
-#define OOP_OOP_ITERATE_DECL_BACKWARDS(OopClosureType, nv_suffix)               \
-  void oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure);
-#endif
-
-
-// Oop iteration macros for definitions.
-// Used to generate definitions in the *Klass.inline.hpp files.
-
-#define OOP_OOP_ITERATE_DEFN(KlassType, OopClosureType, nv_suffix)              \
-void KlassType::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) {  \
-  oop_oop_iterate<nvs_to_bool(nv_suffix)>(obj, closure);                        \
-}
-
-#if INCLUDE_OOP_OOP_ITERATE_BACKWARDS
-#define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix)              \
-void KlassType::oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) {  \
-  oop_oop_iterate_reverse<nvs_to_bool(nv_suffix)>(obj, closure);                          \
-}
-#else
-#define OOP_OOP_ITERATE_DEFN_BACKWARDS(KlassType, OopClosureType, nv_suffix)
-#endif
-
-#define OOP_OOP_ITERATE_DEFN_BOUNDED(KlassType, OopClosureType, nv_suffix)                            \
-void KlassType::oop_oop_iterate_bounded##nv_suffix(oop obj, OopClosureType* closure, MemRegion mr) {  \
-  oop_oop_iterate_bounded<nvs_to_bool(nv_suffix)>(obj, closure, mr);                                  \
-}
-
 #endif // SHARE_VM_OOPS_KLASS_HPP