--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/spi/LoweringProvider.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2011, 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.nodes.spi;
+
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.nodes.ValueNode;
+import org.graalvm.compiler.nodes.memory.address.AddressNode;
+
+import jdk.vm.ci.meta.JavaKind;
+
+/**
+ * Provides a capability for replacing a higher node with one or more lower level nodes.
+ */
+public interface LoweringProvider {
+
+    void lower(Node n, LoweringTool tool);
+
+    /**
+     * Reconstructs the array index from an address node that was created as a lowering of an
+     * indexed access to an array.
+     *
+     * @param elementKind the {@link JavaKind} of the array elements
+     * @param address an {@link AddressNode} pointing to an element in an array
+     * @return a node that gives the index of the element
+     */
+    ValueNode reconstructArrayIndex(JavaKind elementKind, AddressNode address);
+
+    /**
+     * Indicates the smallest width for comparing an integer value on the target platform.
+     */
+    default Integer smallestCompareWidth() {
+        // most platforms only support 32 and 64 bit compares
+        return 32;
+    }
+}