--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.phases/src/org/graalvm/compiler/phases/util/BlockWorkList.java	2016-12-09 00:56:33.696019629 -0800
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2009, 2011, 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.util;
+
+import org.graalvm.compiler.nodes.AbstractMergeNode;
+
+/**
+ * This class implements a worklist for dealing with blocks. The worklist can operate either as a
+ * stack (i.e. first-in / last-out), or as a sorted list, where blocks can be sorted by a supplied
+ * number. The latter usage lends itself naturally to iterative dataflow analysis problems.
+ */
+public class BlockWorkList {
+
+    AbstractMergeNode[] workList;
+    int[] workListNumbers;
+    int workListIndex;
+
+    /**
+     * Adds a block to this list in an unsorted fashion, like a stack.
+     *
+     * @param block the block to add
+     */
+    public void add(AbstractMergeNode block) {
+        if (workList == null) {
+            // worklist not allocated yet
+            allocate();
+        } else if (workListIndex == workList.length) {
+            // need to grow the worklist
+            grow();
+        }
+        // put the block at the end of the array
+        workList[workListIndex++] = block;
+    }
+
+    /**
+     * Adds a block to this list, sorted by the supplied number. The block with the lowest number is
+     * returned upon subsequent removes.
+     *
+     * @param block the block to add
+     * @param number the number used to sort the block
+     */
+    public void addSorted(AbstractMergeNode block, int number) {
+        if (workList == null) {
+            // worklist not allocated yet
+            allocate();
+        } else if (workListIndex == workList.length) {
+            // need to grow the worklist
+            grow();
+        }
+        // put the block at the end of the array
+        workList[workListIndex] = block;
+        workListNumbers[workListIndex] = number;
+        workListIndex++;
+        int i = workListIndex - 2;
+        // push block towards the beginning of the array
+        for (; i >= 0; i--) {
+            int n = workListNumbers[i];
+            if (n >= number) {
+                break; // already in the right position
+            }
+            workList[i + 1] = workList[i]; // bubble b down by one
+            workList[i] = block;           // and overwrite its place with block
+            workListNumbers[i + 1] = n;    // bubble n down by one
+            workListNumbers[i] = number;   // and overwrite its place with number
+        }
+    }
+
+    /**
+     * Removes the next block from this work list. If the blocks have been added in a sorted order,
+     * then the block with the lowest number is returned. Otherwise, the last block added is
+     * returned.
+     *
+     * @return the next block in the list
+     */
+    public AbstractMergeNode removeFromWorkList() {
+        if (workListIndex != 0) {
+            return workList[--workListIndex];
+        }
+        return null;
+    }
+
+    /**
+     * Checks whether the list is empty.
+     *
+     * @return {@code true} if this list is empty
+     */
+    public boolean isEmpty() {
+        return workListIndex == 0;
+    }
+
+    private void allocate() {
+        workList = new AbstractMergeNode[5];
+        workListNumbers = new int[5];
+    }
+
+    private void grow() {
+        int prevLength = workList.length;
+        AbstractMergeNode[] nworkList = new AbstractMergeNode[prevLength * 3];
+        System.arraycopy(workList, 0, nworkList, 0, prevLength);
+        workList = nworkList;
+
+        int[] nworkListNumbers = new int[prevLength * 3];
+        System.arraycopy(workListNumbers, 0, nworkListNumbers, 0, prevLength);
+        workListNumbers = nworkListNumbers;
+    }
+}