--- a/src/hotspot/share/oops/accessDecorators.hpp	Thu Apr 26 12:48:35 2018 -0700
+++ b/src/hotspot/share/oops/accessDecorators.hpp	Thu Apr 26 20:42:43 2018 +0200
@@ -25,6 +25,11 @@
 #ifndef SHARE_OOPS_ACCESSDECORATORS_HPP
 #define SHARE_OOPS_ACCESSDECORATORS_HPP
 
+#include "gc/shared/barrierSetConfig.hpp"
+#include "memory/allocation.hpp"
+#include "metaprogramming/integralConstant.hpp"
+#include "utilities/globalDefinitions.hpp"
+
 // A decorator is an attribute or property that affects the way a memory access is performed in some way.
 // There are different groups of decorators. Some have to do with memory ordering, others to do with,
 // e.g. strength of references, strength of GC barriers, or whether compression should be applied or not.
@@ -216,4 +221,58 @@
                                                     ARRAYCOPY_DISJOINT | ARRAYCOPY_ARRAYOF |
                                                     ARRAYCOPY_ATOMIC | ARRAYCOPY_ALIGNED;
 
+// Keep track of the last decorator.
+const DecoratorSet DECORATOR_LAST = UCONST64(1) << 30;
+
+namespace AccessInternal {
+  // This class adds implied decorators that follow according to decorator rules.
+  // For example adding default reference strength and default memory ordering
+  // semantics.
+  template <DecoratorSet input_decorators>
+  struct DecoratorFixup: AllStatic {
+    // If no reference strength has been picked, then strong will be picked
+    static const DecoratorSet ref_strength_default = input_decorators |
+      (((ON_DECORATOR_MASK & input_decorators) == 0 && (INTERNAL_VALUE_IS_OOP & input_decorators) != 0) ?
+       ON_STRONG_OOP_REF : INTERNAL_EMPTY);
+    // If no memory ordering has been picked, unordered will be picked
+    static const DecoratorSet memory_ordering_default = ref_strength_default |
+      ((MO_DECORATOR_MASK & ref_strength_default) == 0 ? MO_UNORDERED : INTERNAL_EMPTY);
+    // If no barrier strength has been picked, normal will be used
+    static const DecoratorSet barrier_strength_default = memory_ordering_default |
+      ((AS_DECORATOR_MASK & memory_ordering_default) == 0 ? AS_NORMAL : INTERNAL_EMPTY);
+    // Heap array accesses imply it is a heap access
+    static const DecoratorSet heap_array_is_in_heap = barrier_strength_default |
+      ((IN_HEAP_ARRAY & barrier_strength_default) != 0 ? IN_HEAP : INTERNAL_EMPTY);
+    static const DecoratorSet conc_root_is_root = heap_array_is_in_heap |
+      ((IN_CONCURRENT_ROOT & heap_array_is_in_heap) != 0 ? IN_ROOT : INTERNAL_EMPTY);
+    static const DecoratorSet archive_root_is_root = conc_root_is_root |
+      ((IN_ARCHIVE_ROOT & conc_root_is_root) != 0 ? IN_ROOT : INTERNAL_EMPTY);
+    static const DecoratorSet value = archive_root_is_root | BT_BUILDTIME_DECORATORS;
+  };
+
+  // This function implements the above DecoratorFixup rules, but without meta
+  // programming for code generation that does not use templates.
+  inline DecoratorSet decorator_fixup(DecoratorSet input_decorators) {
+    // If no reference strength has been picked, then strong will be picked
+    DecoratorSet ref_strength_default = input_decorators |
+      (((ON_DECORATOR_MASK & input_decorators) == 0 && (INTERNAL_VALUE_IS_OOP & input_decorators) != 0) ?
+       ON_STRONG_OOP_REF : INTERNAL_EMPTY);
+    // If no memory ordering has been picked, unordered will be picked
+    DecoratorSet memory_ordering_default = ref_strength_default |
+      ((MO_DECORATOR_MASK & ref_strength_default) == 0 ? MO_UNORDERED : INTERNAL_EMPTY);
+    // If no barrier strength has been picked, normal will be used
+    DecoratorSet barrier_strength_default = memory_ordering_default |
+      ((AS_DECORATOR_MASK & memory_ordering_default) == 0 ? AS_NORMAL : INTERNAL_EMPTY);
+    // Heap array accesses imply it is a heap access
+    DecoratorSet heap_array_is_in_heap = barrier_strength_default |
+      ((IN_HEAP_ARRAY & barrier_strength_default) != 0 ? IN_HEAP : INTERNAL_EMPTY);
+    DecoratorSet conc_root_is_root = heap_array_is_in_heap |
+      ((IN_CONCURRENT_ROOT & heap_array_is_in_heap) != 0 ? IN_ROOT : INTERNAL_EMPTY);
+    DecoratorSet archive_root_is_root = conc_root_is_root |
+      ((IN_ARCHIVE_ROOT & conc_root_is_root) != 0 ? IN_ROOT : INTERNAL_EMPTY);
+    DecoratorSet value = archive_root_is_root | BT_BUILDTIME_DECORATORS;
+    return value;
+  }
+}
+
 #endif // SHARE_OOPS_ACCESSDECORATORS_HPP