--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/type/StampPair.java	2016-12-09 00:47:17.308494983 -0800
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016, 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 org.graalvm.compiler.core.common.type;
+
+/**
+ * A pair of stamp with one being the stamp that can be trusted and the other one being a guess that
+ * needs a dynamic check to be used.
+ */
+public final class StampPair {
+
+    private final Stamp trustedStamp;
+    private final Stamp uncheckedStamp;
+
+    private StampPair(Stamp trustedStamp, Stamp uncheckedStamp) {
+        assert trustedStamp != null;
+        this.trustedStamp = trustedStamp;
+        this.uncheckedStamp = uncheckedStamp;
+    }
+
+    public static StampPair create(Stamp trustedStamp, Stamp uncheckedStamp) {
+        return new StampPair(trustedStamp, uncheckedStamp);
+    }
+
+    public static StampPair createSingle(Stamp stamp) {
+        return new StampPair(stamp, null);
+    }
+
+    public Stamp getUncheckedStamp() {
+        return uncheckedStamp;
+    }
+
+    public Stamp getTrustedStamp() {
+        return trustedStamp;
+    }
+
+    @Override
+    public String toString() {
+        if (uncheckedStamp == null) {
+            return trustedStamp.toString();
+        } else {
+            return trustedStamp + " (unchecked=" + uncheckedStamp + ")";
+        }
+    }
+}