--- old/src/share/vm/oops/oop.inline.hpp	2017-08-17 11:33:46.483863226 -0400
+++ new/src/share/vm/oops/oop.inline.hpp	2017-08-17 11:33:46.251466314 -0400
@@ -533,9 +533,8 @@
   return mark()->has_bias_pattern();
 }
 
-// used only for asserts
-bool oopDesc::is_oop(bool ignore_mark_word) const {
-  oop obj = (oop) this;
+// used only for asserts and guarantees
+inline bool oopDesc::is_oop(oop obj, bool ignore_mark_word) {
   if (!check_obj_alignment(obj)) return false;
   if (!Universe::heap()->is_in_reserved(obj)) return false;
   // obj is aligned and accessible in heap
@@ -548,16 +547,15 @@
   if (ignore_mark_word) {
     return true;
   }
-  if (mark() != NULL) {
+  if (obj->mark() != NULL) {
     return true;
   }
   return !SafepointSynchronize::is_at_safepoint();
 }
 
-
-// used only for asserts
-bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
-  return this == NULL ? true : is_oop(ignore_mark_word);
+// used only for asserts and guarantees
+inline bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) {
+  return obj == NULL ? true : is_oop(obj, ignore_mark_word);
 }
 
 #ifndef PRODUCT