--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.code/src/jdk/vm/ci/code/site/Mark.java	2017-02-15 16:55:36.607756184 -0800
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2009, 2016, 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.
+ */
+package jdk.vm.ci.code.site;
+
+import java.util.Objects;
+
+/**
+ * Associates arbitrary information with a position in machine code. For example, HotSpot specific
+ * code in a compiler backend may use this to denote the position of a safepoint, exception handler
+ * entry point, verified entry point etc.
+ */
+public final class Mark extends Site {
+
+    /**
+     * An object denoting extra semantic information about the machine code position of this mark.
+     */
+    public final Object id;
+
+    /**
+     * Creates a mark that associates {@code id} with the machine code position {@code pcOffset}.
+     *
+     * @param pcOffset
+     * @param id
+     */
+    public Mark(int pcOffset, Object id) {
+        super(pcOffset);
+        this.id = id;
+    }
+
+    @Override
+    public String toString() {
+        if (id == null) {
+            return String.format("%d[<mark>]", pcOffset);
+        } else if (id instanceof Integer) {
+            return String.format("%d[<mark with id %s>]", pcOffset, Integer.toHexString((Integer) id));
+        } else {
+            return String.format("%d[<mark with id %s>]", pcOffset, id.toString());
+        }
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof Mark) {
+            Mark that = (Mark) obj;
+            if (this.pcOffset == that.pcOffset && Objects.equals(this.id, that.id)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}