--- old/src/share/vm/oops/klass.cpp	2017-04-25 16:45:22.075173553 +0200
+++ new/src/share/vm/oops/klass.cpp	2017-04-25 16:45:21.931173558 +0200
@@ -36,14 +36,12 @@
 #include "oops/instanceKlass.hpp"
 #include "oops/klass.inline.hpp"
 #include "oops/oop.inline.hpp"
+#include "runtime/access.inline.hpp"
 #include "runtime/atomic.hpp"
 #include "runtime/orderAccess.inline.hpp"
 #include "trace/traceMacros.hpp"
 #include "utilities/macros.hpp"
 #include "utilities/stack.inline.hpp"
-#if INCLUDE_ALL_GCS
-#include "gc/g1/g1SATBCardTableModRefBS.hpp"
-#endif // INCLUDE_ALL_GCS
 
 bool Klass::is_cloneable() const {
   return _access_flags.is_cloneable_fast() ||
@@ -440,45 +438,8 @@
   }
 }
 
-void Klass::klass_update_barrier_set(oop v) {
-  record_modified_oops();
-}
-
-// This barrier is used by G1 to remember the old oop values, so
-// that we don't forget any objects that were live at the snapshot at
-// the beginning. This function is only used when we write oops into Klasses.
-void Klass::klass_update_barrier_set_pre(oop* p, oop v) {
-#if INCLUDE_ALL_GCS
-  if (UseG1GC) {
-    oop obj = *p;
-    if (obj != NULL) {
-      G1SATBCardTableModRefBS::enqueue(obj);
-    }
-  }
-#endif
-}
-
-void Klass::klass_oop_store(oop* p, oop v) {
-  assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
-  assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
-
-  // do the store
-  if (always_do_update_barrier) {
-    klass_oop_store((volatile oop*)p, v);
-  } else {
-    klass_update_barrier_set_pre(p, v);
-    *p = v;
-    klass_update_barrier_set(v);
-  }
-}
-
-void Klass::klass_oop_store(volatile oop* p, oop v) {
-  assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
-  assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
-
-  klass_update_barrier_set_pre((oop*)p, v); // Cast away volatile.
-  OrderAccess::release_store_ptr(p, v);
-  klass_update_barrier_set(v);
+void Klass::set_java_mirror(oop m) {
+  KlassAccess<MO_RELEASE>::oop_store_at(this, in_bytes(java_mirror_offset()), m);
 }
 
 void Klass::oops_do(OopClosure* cl) {
@@ -565,7 +526,15 @@
   return NULL;
 }
 
-oop Klass::class_loader() const { return class_loader_data()->class_loader(); }
+oop Klass::class_loader() const       { return class_loader_data()->class_loader(); }
+
+oop* Klass::klass_holder_addr() const {
+  return class_loader_data()->class_loader_addr();
+}
+
+oop Klass::klass_holder() const {
+  return RootAccess<GC_ACCESS_ON_PHANTOM>::oop_load(klass_holder_addr());
+}
 
 // In product mode, this function doesn't have virtual function calls so
 // there might be some performance advantage to handling InstanceKlass here.