--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zAddressRangeMap.hpp	2018-06-06 00:41:35.837926711 +0200
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef SHARE_GC_Z_ZADDRESSRANGEMAP_HPP
+#define SHARE_GC_Z_ZADDRESSRANGEMAP_HPP
+
+#include "memory/allocation.hpp"
+
+template<typename T, size_t AddressRangeShift>
+class ZAddressRangeMapIterator;
+
+template <typename T, size_t AddressRangeShift>
+class ZAddressRangeMap {
+  friend class VMStructs;
+  friend class ZAddressRangeMapIterator<T, AddressRangeShift>;
+
+private:
+  T* const _map;
+
+  size_t index_for_addr(uintptr_t addr) const;
+  size_t size() const;
+
+public:
+  ZAddressRangeMap();
+  ~ZAddressRangeMap();
+
+  T get(uintptr_t addr) const;
+  void put(uintptr_t addr, T value);
+};
+
+template <typename T, size_t AddressRangeShift>
+class ZAddressRangeMapIterator : public StackObj {
+public:
+  const ZAddressRangeMap<T, AddressRangeShift>* const _map;
+  size_t                                              _next;
+
+public:
+  ZAddressRangeMapIterator(const ZAddressRangeMap<T, AddressRangeShift>* map);
+
+  bool next(T* value);
+};
+
+#endif // SHARE_GC_Z_ZADDRESSRANGEMAP_HPP