--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.jtt/src/com/oracle/graal/jtt/optimize/SchedulingBug_01.java	Thu Apr 23 20:31:35 2015 +0200
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2015, 2015, 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 com.oracle.graal.jtt.optimize;
+
+import org.junit.*;
+
+import com.oracle.graal.jtt.*;
+
+/*
+ */
+public class SchedulingBug_01 extends JTTTest {
+
+    private static class VolatileBoxHolder {
+        volatile Integer box;
+    }
+
+    public static int test(VolatileBoxHolder a, VolatileBoxHolder b) {
+        int value = a.box;
+        int result = 0;
+        if (b.box != null) {
+            result += value;
+        }
+        return result + value;
+    }
+
+    @Test
+    public void run0() throws Throwable {
+        runTest("test", new VolatileBoxHolder(), new VolatileBoxHolder());
+    }
+
+}

--- a/graal/com.oracle.graal.phases/src/com/oracle/graal/phases/schedule/SchedulePhase.java	Thu Apr 23 20:27:15 2015 +0200
+++ b/graal/com.oracle.graal.phases/src/com/oracle/graal/phases/schedule/SchedulePhase.java	Thu Apr 23 20:31:35 2015 +0200
@@ -597,18 +597,19 @@
         for (int i = 1; i < oldList.size(); ++i) {
             Node n = oldList.get(i);
             if (unprocessed.isMarked(n)) {
-                if (n instanceof MemoryCheckpoint) {
-                    assert n instanceof FixedNode;
-                    if (watchList.size() > 0) {
-                        // Check whether we need to commit reads from the watch list.
-                        checkWatchList(b, nodeToBlock, unprocessed, newList, watchList, n);
+                if (n instanceof MemoryNode) {
+                    if (n instanceof MemoryCheckpoint) {
+                        assert n instanceof FixedNode;
+                        if (watchList.size() > 0) {
+                            // Check whether we need to commit reads from the watch list.
+                            checkWatchList(b, nodeToBlock, unprocessed, newList, watchList, n);
+                        }
                     }
-
                     // Add potential dependent reads to the watch list.
                     for (Node usage : n.usages()) {
                         if (usage instanceof FloatingReadNode) {
                             FloatingReadNode floatingReadNode = (FloatingReadNode) usage;
-                            if (nodeToBlock.get(floatingReadNode) == b && floatingReadNode.getLastLocationAccess() == n) {
+                            if (nodeToBlock.get(floatingReadNode) == b && floatingReadNode.getLastLocationAccess() == n && !(n instanceof MemoryPhiNode)) {
                                 watchList.add(floatingReadNode);
                             }
                         }