--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/utilities/jfrBigEndian.hpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2012, 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_VM_JFR_UTILITIES_JFRBIGENDIAN_HPP
+#define SHARE_VM_JFR_UTILITIES_JFRBIGENDIAN_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/bytes.hpp"
+#include "utilities/macros.hpp"
+
+#ifndef VM_LITTLE_ENDIAN
+# define bigendian_16(x) (x)
+# define bigendian_32(x) (x)
+# define bigendian_64(x) (x)
+#else
+# define bigendian_16(x) Bytes::swap_u2(x)
+# define bigendian_32(x) Bytes::swap_u4(x)
+# define bigendian_64(x) Bytes::swap_u8(x)
+#endif
+
+class JfrBigEndian : AllStatic {
+ private:
+  template <typename T>
+  static T read_bytes(const address location);
+  template <typename T>
+  static T read_unaligned(const address location);
+ public:
+  static bool platform_supports_unaligned_reads(void);
+  static bool is_aligned(const void* location, size_t size);
+  template <typename T>
+  static T read(const void* location);
+};
+
+inline bool JfrBigEndian::is_aligned(const void* location, size_t size) {
+  assert(size <= sizeof(u8), "just checking");
+  if (size == sizeof(u1)) {
+    return true;
+  }
+  // check address alignment for datum access
+  return (((uintptr_t)location & (size -1)) == 0);
+}
+
+template <>
+inline u1 JfrBigEndian::read_bytes(const address location) {
+  return (*location & 0xFF);
+}
+
+template <>
+inline u2 JfrBigEndian::read_bytes(const address location) {
+  return Bytes::get_Java_u2(location);
+}
+
+template <>
+inline u4 JfrBigEndian::read_bytes(const address location) {
+  return Bytes::get_Java_u4(location);
+}
+
+template <>
+inline u8 JfrBigEndian::read_bytes(const address location) {
+  return Bytes::get_Java_u8(location);
+}
+
+template <typename T>
+inline T JfrBigEndian::read_unaligned(const address location) {
+  assert(location != NULL, "just checking");
+  switch (sizeof(T)) {
+    case sizeof(u1) :
+      return read_bytes<u1>(location);
+    case sizeof(u2):
+      return read_bytes<u2>(location);
+    case sizeof(u4):
+      return read_bytes<u4>(location);
+    case sizeof(u8):
+      return read_bytes<u8>(location);
+    default:
+      assert(false, "not reach");
+  }
+  return 0;
+}
+
+inline bool JfrBigEndian::platform_supports_unaligned_reads(void) {
+#if defined(IA32) || defined(AMD64)
+  return true;
+#elif defined(SPARC) || defined(ARM) || defined(AARCH64)
+  return false;
+#else
+  #warning "Unconfigured platform"
+  return false;
+#endif
+}
+
+template<typename T>
+inline T JfrBigEndian::read(const void* location) {
+  assert(location != NULL, "just checking");
+  assert(sizeof(T) <= sizeof(u8), "no support for arbitrary sizes");
+  if (sizeof(T) == sizeof(u1)) {
+    return *(T*)location;
+  }
+  if (is_aligned(location, sizeof(T)) || platform_supports_unaligned_reads()) {
+    // fastest case
+    switch (sizeof(T)) {
+      case sizeof(u1):
+        return *(T*)location;
+      case sizeof(u2):
+        return bigendian_16(*(T*)(location));
+      case sizeof(u4):
+        return bigendian_32(*(T*)(location));
+      case sizeof(u8):
+        return bigendian_64(*(T*)(location));
+    }
+  }
+  return read_unaligned<T>((const address)location);
+}
+
+#endif // SHARE_VM_JFR_UTILITIES_JFRBIGENDIAN_HPP