--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.max.graal.compiler/src/com/oracle/max/graal/compiler/phases/LoweringPhase.java	Thu Jun 09 17:28:56 2011 +0200
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 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 com.oracle.max.graal.compiler.phases;
+
+import java.util.*;
+
+import com.oracle.max.graal.compiler.*;
+import com.oracle.max.graal.compiler.ir.*;
+import com.oracle.max.graal.compiler.schedule.*;
+import com.oracle.max.graal.graph.*;
+
+public class LoweringPhase extends Phase {
+    @Override
+    protected void run(Graph graph) {
+        NodeMap<Node> javaBlockNodes = graph.createNodeMap();
+        NodeBitMap nodeBitMap = graph.createNodeBitMap();
+        for (Node n : graph.getNodes()) {
+            if (n instanceof FixedNode) {
+                LoweringOp op = n.lookup(LoweringOp.class);
+                if (op != null) {
+                    Node javaBlockNode = getJavaBlockNode(javaBlockNodes, n, nodeBitMap);
+                }
+            }
+
+        }
+    }
+
+    private Node getJavaBlockNode(NodeMap<Node> javaBlockNodes, Node n, NodeBitMap nodeBitMap) {
+        assert n instanceof FixedNode;
+        if (javaBlockNodes.get(n) == null) {
+
+            Node truePred = null;
+            int count = 0;
+            for (Node pred : n.predecessors()) {
+                if (pred instanceof FixedNode) {
+                    truePred = pred;
+                    count++;
+                }
+            }
+
+            assert count > 0;
+            if (count == 1) {
+                if (Schedule.trueSuccessorCount(truePred) == 1) {
+                    javaBlockNodes.set(n, getJavaBlockNode(javaBlockNodes, truePred, nodeBitMap));
+                } else {
+                    // Single predecessor is a split => we are our own block node.
+                    javaBlockNodes.set(n, n);
+                }
+            } else {
+                Node dominator = null;
+                for (Node pred : n.predecessors()) {
+                    if (pred instanceof FixedNode) {
+                       dominator = getCommonDominator(dominator, pred, nodeBitMap);
+                    }
+                }
+            }
+        }
+
+        assert Schedule.truePredecessorCount(javaBlockNodes.get(n)) == 1;
+        return javaBlockNodes.get(n);
+    }
+
+    private Node getCommonDominator(Node a, Node b, NodeBitMap map) {
+        if (a == null) {
+            return b;
+        }
+
+        if (b == null) {
+            return a;
+        }
+
+
+        map.clearAll();
+    }
+
+    public interface LoweringOp extends Op {
+        Node lower(Node node);
+    }
+}