--- old/src/hotspot/share/gc/shared/genOopClosures.inline.hpp	2018-03-22 16:37:44.376885472 +0100
+++ new/src/hotspot/share/gc/shared/genOopClosures.inline.hpp	2018-03-22 16:37:44.176885479 +0100
@@ -31,6 +31,8 @@
 #include "gc/shared/genOopClosures.hpp"
 #include "gc/shared/generation.hpp"
 #include "gc/shared/space.hpp"
+#include "oops/access.inline.hpp"
+#include "oops/compressedOops.inline.hpp"
 
 inline OopsInGenClosure::OopsInGenClosure(Generation* gen) :
   ExtendedOopClosure(gen->ref_processor()), _orig_gen(gen), _rs(NULL) {
@@ -48,9 +50,9 @@
 
 template <class T> inline void OopsInGenClosure::do_barrier(T* p) {
   assert(generation()->is_in_reserved(p), "expected ref in generation");
-  T heap_oop = oopDesc::load_heap_oop(p);
-  assert(!oopDesc::is_null(heap_oop), "expected non-null oop");
-  oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+  T heap_oop = RawAccess<>::oop_load(p);
+  assert(!CompressedOops::is_null(heap_oop), "expected non-null oop");
+  oop obj = CompressedOops::decode_not_null(heap_oop);
   // If p points to a younger generation, mark the card.
   if ((HeapWord*)obj < _gen_boundary) {
     _rs->inline_write_ref_field_gc(p, obj);
@@ -59,9 +61,9 @@
 
 template <class T> inline void OopsInGenClosure::par_do_barrier(T* p) {
   assert(generation()->is_in_reserved(p), "expected ref in generation");
-  T heap_oop = oopDesc::load_heap_oop(p);
-  assert(!oopDesc::is_null(heap_oop), "expected non-null oop");
-  oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+  T heap_oop = RawAccess<>::oop_load(p);
+  assert(!CompressedOops::is_null(heap_oop), "expected non-null oop");
+  oop obj = CompressedOops::decode_not_null(heap_oop);
   // If p points to a younger generation, mark the card.
   if ((HeapWord*)obj < gen_boundary()) {
     rs()->write_ref_field_gc_par(p, obj);
@@ -78,15 +80,15 @@
 // NOTE! Any changes made here should also be made
 // in FastScanClosure::do_oop_work()
 template <class T> inline void ScanClosure::do_oop_work(T* p) {
-  T heap_oop = oopDesc::load_heap_oop(p);
+  T heap_oop = RawAccess<>::oop_load(p);
   // Should we copy the obj?
-  if (!oopDesc::is_null(heap_oop)) {
-    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+  if (!CompressedOops::is_null(heap_oop)) {
+    oop obj = CompressedOops::decode_not_null(heap_oop);
     if ((HeapWord*)obj < _boundary) {
       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
       oop new_obj = obj->is_forwarded() ? obj->forwardee()
                                         : _g->copy_to_survivor_space(obj);
-      oopDesc::encode_store_heap_oop_not_null(p, new_obj);
+      RawAccess<OOP_NOT_NULL>::oop_store(p, new_obj);
     }
 
     if (is_scanning_a_cld()) {
@@ -104,15 +106,15 @@
 // NOTE! Any changes made here should also be made
 // in ScanClosure::do_oop_work()
 template <class T> inline void FastScanClosure::do_oop_work(T* p) {
-  T heap_oop = oopDesc::load_heap_oop(p);
+  T heap_oop = RawAccess<>::oop_load(p);
   // Should we copy the obj?
-  if (!oopDesc::is_null(heap_oop)) {
-    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+  if (!CompressedOops::is_null(heap_oop)) {
+    oop obj = CompressedOops::decode_not_null(heap_oop);
     if ((HeapWord*)obj < _boundary) {
       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
       oop new_obj = obj->is_forwarded() ? obj->forwardee()
                                         : _g->copy_to_survivor_space(obj);
-      oopDesc::encode_store_heap_oop_not_null(p, new_obj);
+      RawAccess<OOP_NOT_NULL>::oop_store(p, new_obj);
       if (is_scanning_a_cld()) {
         do_cld_barrier();
       } else if (_gc_barrier) {
@@ -127,9 +129,9 @@
 inline void FastScanClosure::do_oop_nv(narrowOop* p) { FastScanClosure::do_oop_work(p); }
 
 template <class T> void FilteringClosure::do_oop_work(T* p) {
-  T heap_oop = oopDesc::load_heap_oop(p);
-  if (!oopDesc::is_null(heap_oop)) {
-    oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+  T heap_oop = RawAccess<>::oop_load(p);
+  if (!CompressedOops::is_null(heap_oop)) {
+    oop obj = CompressedOops::decode_not_null(heap_oop);
     if ((HeapWord*)obj < _boundary) {
       _cl->do_oop(p);
     }
@@ -142,14 +144,13 @@
 // Note similarity to ScanClosure; the difference is that
 // the barrier set is taken care of outside this closure.
 template <class T> inline void ScanWeakRefClosure::do_oop_work(T* p) {
-  assert(!oopDesc::is_null(*p), "null weak reference?");
-  oop obj = oopDesc::load_decode_heap_oop_not_null(p);
+  oop obj = RawAccess<OOP_NOT_NULL>::oop_load(p);
   // weak references are sometimes scanned twice; must check
   // that to-space doesn't already contain this object
   if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
     oop new_obj = obj->is_forwarded() ? obj->forwardee()
                                       : _g->copy_to_survivor_space(obj);
-    oopDesc::encode_store_heap_oop_not_null(p, new_obj);
+    RawAccess<OOP_NOT_NULL>::oop_store(p, new_obj);
   }
 }