--- a/src/hotspot/share/oops/oop.inline.hpp	Tue Jun 05 09:23:30 2018 +0200
+++ b/src/hotspot/share/oops/oop.inline.hpp	Tue Jun 05 09:29:15 2018 +0200
@@ -71,8 +71,8 @@
   return HeapAccess<>::atomic_cmpxchg_at(new_mark, as_oop(), mark_offset_in_bytes(), old_mark);
 }
 
-markOop oopDesc::cas_set_mark_raw(markOop new_mark, markOop old_mark) {
-  return Atomic::cmpxchg(new_mark, &_mark, old_mark);
+markOop oopDesc::cas_set_mark_raw(markOop new_mark, markOop old_mark, atomic_memory_order order) {
+  return Atomic::cmpxchg(new_mark, &_mark, old_mark, order);
 }
 
 void oopDesc::init_mark() {
@@ -342,14 +342,14 @@
 }
 
 // Used by parallel scavengers
-bool oopDesc::cas_forward_to(oop p, markOop compare) {
+bool oopDesc::cas_forward_to(oop p, markOop compare, atomic_memory_order order) {
   assert(check_obj_alignment(p),
          "forwarding to something not aligned");
   assert(Universe::heap()->is_in_reserved(p),
          "forwarding to something not in heap");
   markOop m = markOopDesc::encode_pointer_as_mark(p);
   assert(m->decode_pointer() == p, "encoding must be reversable");
-  return cas_set_mark_raw(m, compare) == compare;
+  return cas_set_mark_raw(m, compare, order) == compare;
 }
 
 oop oopDesc::forward_to_atomic(oop p) {
@@ -381,6 +381,14 @@
   return (oop) mark_raw()->decode_pointer();
 }
 
+// Note that the forwardee is not the same thing as the displaced_mark.
+// The forwardee is used when copying during scavenge and mark-sweep.
+// It does need to clear the low two locking- and GC-related bits.
+oop oopDesc::forwardee_acquire() const {
+  markOop m = OrderAccess::load_acquire(&_mark);
+  return (oop) m->decode_pointer();
+}
+
 // The following method needs to be MT safe.
 uint oopDesc::age() const {
   assert(!is_forwarded(), "Attempt to read age from forwarded mark");