--- old/src/share/vm/gc/shared/space.inline.hpp	2015-10-14 13:54:06.008088009 +0200
+++ new/src/share/vm/gc/shared/space.inline.hpp	2015-10-14 13:54:05.903090548 +0200
@@ -121,14 +121,16 @@
 
   while (q < t) {
     assert(!space->scanned_block_is_obj(q) ||
-           oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() ||
-           oop(q)->mark()->has_bias_pattern(),
+           space->make_oop(q)->mark()->is_marked() ||
+           space->make_oop(q)->mark()->is_unlocked() ||
+           space->make_oop(q)->mark()->has_bias_pattern() ||
+           oopDesc::bs()->read_barrier(space->make_oop(q)) != space->make_oop(q),
            "these are the only valid states during a mark sweep");
-    if (space->scanned_block_is_obj(q) && oop(q)->is_gc_marked()) {
+    if (space->scanned_block_is_obj(q) && space->make_oop(q)->is_gc_marked()) {
       // prefetch beyond q
       Prefetch::write(q, interval);
       size_t size = space->scanned_block_size(q);
-      compact_top = cp->space->forward(oop(q), size, cp, compact_top);
+      compact_top = cp->space->forward(space->make_oop(q), size, cp, compact_top);
       q += size;
       end_of_live = q;
     } else {
@@ -138,14 +140,14 @@
         // prefetch beyond end
         Prefetch::write(end, interval);
         end += space->scanned_block_size(end);
-      } while (end < t && (!space->scanned_block_is_obj(end) || !oop(end)->is_gc_marked()));
+      } while (end < t && (!space->scanned_block_is_obj(end) || !space->make_oop(end)->is_gc_marked()));
 
       // see if we might want to pretend this object is alive so that
       // we don't have to compact quite as often.
       if (allowed_deadspace > 0 && q == compact_top) {
         size_t sz = pointer_delta(end, q);
         if (space->insert_deadspace(allowed_deadspace, q, sz)) {
-          compact_top = cp->space->forward(oop(q), sz, cp, compact_top);
+          compact_top = cp->space->forward(space->make_oop(q), sz, cp, compact_top);
           q = end;
           end_of_live = end;
           continue;
@@ -161,7 +163,7 @@
 
       // record the current LiveRange object.
       // liveRange->start() is overlaid on the mark word.
-      liveRange = (LiveRange*)q;
+      liveRange = (LiveRange*) (HeapWord*) space->make_oop(q);
       liveRange->set_start(end);
       liveRange->set_end(end);
 
@@ -199,7 +201,7 @@
 
   assert(space->_first_dead <= space->_end_of_live, "Stands to reason, no?");
 
-  if (q < t && space->_first_dead > q && !oop(q)->is_gc_marked()) {
+  if (q < t && space->_first_dead > q && !space->make_oop(q)->is_gc_marked()) {
     // we have a chunk of the space which hasn't moved and we've
     // reinitialized the mark word during the previous pass, so we can't
     // use is_gc_marked for the traversal.
@@ -214,7 +216,7 @@
       assert(space->block_is_obj(q), "should be at block boundaries, and should be looking at objs");
 
       // point all the oops to the new location
-      size_t size = MarkSweep::adjust_pointers(oop(q));
+      size_t size = MarkSweep::adjust_pointers(space->make_oop(q));
       size = space->adjust_obj_size(size);
 
       q += size;
@@ -235,10 +237,10 @@
   while (q < t) {
     // prefetch beyond q
     Prefetch::write(q, interval);
-    if (oop(q)->is_gc_marked()) {
+    if (space->make_oop(q)->is_gc_marked()) {
       // q is alive
       // point all the oops to the new location
-      size_t size = MarkSweep::adjust_pointers(oop(q));
+      size_t size = MarkSweep::adjust_pointers(space->make_oop(q));
       size = space->adjust_obj_size(size);
       debug_only(prev_q = q);
       q += size;
@@ -246,7 +248,7 @@
       // q is not a live object, so its mark should point at the next
       // live object
       debug_only(prev_q = q);
-      q = (HeapWord*) oop(q)->mark()->decode_pointer();
+      q = (HeapWord*) space->make_oop(q)->mark()->decode_pointer();
       assert(q > prev_q, "we should be moving forward through memory");
     }
   }
@@ -263,7 +265,7 @@
   HeapWord* const t = space->_end_of_live;
   debug_only(HeapWord* prev_q = NULL);
 
-  if (q < t && space->_first_dead > q && !oop(q)->is_gc_marked()) {
+  if (q < t && space->_first_dead > q && !space->make_oop(q)->is_gc_marked()) {
     #ifdef ASSERT // Debug only
       // we have a chunk of the space which hasn't moved and we've reinitialized
       // the mark word during the previous pass, so we can't use is_gc_marked for
@@ -272,7 +274,7 @@
 
       while (q < end) {
         size_t size = space->obj_size(q);
-        assert(!oop(q)->is_gc_marked(), "should be unmarked (special dense prefix handling)");
+        assert(!space->make_oop(q)->is_gc_marked(), "should be unmarked (special dense prefix handling)");
         prev_q = q;
         q += size;
       }
@@ -289,10 +291,10 @@
   const intx scan_interval = PrefetchScanIntervalInBytes;
   const intx copy_interval = PrefetchCopyIntervalInBytes;
   while (q < t) {
-    if (!oop(q)->is_gc_marked()) {
+    if (!space->make_oop(q)->is_gc_marked()) {
       // mark is pointer to next marked oop
       debug_only(prev_q = q);
-      q = (HeapWord*) oop(q)->mark()->decode_pointer();
+      q = (HeapWord*) space->make_oop(q)->mark()->decode_pointer();
       assert(q > prev_q, "we should be moving forward through memory");
     } else {
       // prefetch beyond q
@@ -300,14 +302,14 @@
 
       // size and destination
       size_t size = space->obj_size(q);
-      HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee();
+      HeapWord* compaction_top = (HeapWord*)space->make_oop(q)->forwardee();
 
       // prefetch beyond compaction_top
       Prefetch::write(compaction_top, copy_interval);
 
       // copy object and reinit its mark
       assert(q != compaction_top, "everything in this pass should be moving");
-      Copy::aligned_conjoint_words(q, compaction_top, size);
+      Copy::aligned_conjoint_words((HeapWord*) space->make_oop(q), compaction_top, size);
       oop(compaction_top)->init_mark();
       assert(oop(compaction_top)->klass() != NULL, "should have a class");