--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.phases/src/org/graalvm/compiler/phases/VerifyPhase.java	2017-02-15 17:08:25.215298305 -0800
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2013, 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.phases;
+
+import org.graalvm.compiler.nodes.StructuredGraph;
+
+/***
+ * This phase serves as a verification, in order to check the graph for certain properties. The
+ * {@link #verify(StructuredGraph, Object)} method will be used as an assertion, and implements the
+ * actual check. Instead of returning false, it is also valid to throw an {@link VerificationError}
+ * in the implemented {@link #verify(StructuredGraph, Object)} method.
+ */
+public abstract class VerifyPhase<C> extends BasePhase<C> {
+
+    /**
+     * Thrown when verification performed by a {@link VerifyPhase} fails.
+     */
+    @SuppressWarnings("serial")
+    public static class VerificationError extends AssertionError {
+
+        public VerificationError(String message) {
+            super(message);
+        }
+
+        public VerificationError(String format, Object... args) {
+            super(String.format(format, args));
+        }
+
+        public VerificationError(String message, Throwable cause) {
+            super(message, cause);
+        }
+    }
+
+    @Override
+    protected final void run(StructuredGraph graph, C context) {
+        assert verify(graph, context);
+    }
+
+    /**
+     * Performs the actual verification.
+     *
+     * @throws VerificationError if the verification fails
+     */
+    protected abstract boolean verify(StructuredGraph graph, C context);
+}