--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/GuardedValueNode.java	Tue Jun 25 10:05:04 2013 +0200
@@ -0,0 +1,75 @@
+/*
+ * 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 com.oracle.graal.nodes;
+
+import com.oracle.graal.api.meta.*;
+import com.oracle.graal.graph.*;
+import com.oracle.graal.nodes.extended.*;
+import com.oracle.graal.nodes.spi.*;
+
+/**
+ * A node that changes the type of its input, usually narrowing it. For example, a GuardedValueNode
+ * is used to keep the nodes depending on guards inside a loop during speculative guard movement.
+ * 
+ * A GuardedValueNode will only go away if its guard is null or {@link StructuredGraph#start()}.
+ */
+public class GuardedValueNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, Node.IterableNodeType, GuardingNode, Canonicalizable {
+
+    @Input private ValueNode object;
+
+    public ValueNode object() {
+        return object;
+    }
+
+    public GuardedValueNode(ValueNode object, GuardingNode guard) {
+        super(object.stamp(), guard);
+        this.object = object;
+    }
+
+    @Override
+    public void generate(LIRGeneratorTool generator) {
+        if (object.kind() != Kind.Void && object.kind() != Kind.Illegal) {
+            generator.setResult(this, generator.operand(object));
+        }
+    }
+
+    @Override
+    public boolean inferStamp() {
+        return updateStamp(stamp().join(object().stamp()));
+    }
+
+    @Override
+    public void virtualize(VirtualizerTool tool) {
+        State state = tool.getObjectState(object);
+        if (state != null && state.getState() == EscapeState.Virtual) {
+            tool.replaceWithVirtual(state.getVirtualObject());
+        }
+    }
+
+    public ValueNode canonical(CanonicalizerTool tool) {
+        if (getGuard() == graph().start()) {
+            return object();
+        }
+        return this;
+    }
+}

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/PiNode.java	Tue Jun 25 00:11:45 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/PiNode.java	Tue Jun 25 10:05:04 2013 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 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
@@ -29,8 +29,12 @@
 import com.oracle.graal.nodes.type.*;
 
 /**
- * A node that changes the type of its input, usually narrowing it. For example, a PI node refines
+ * A node that changes the type of its input, usually narrowing it. For example, a PiNode refines
  * the type of a receiver during type-guarded inlining to be the type tested by the guard.
+ * 
+ * In contrast to a {@link GuardedValueNode}, a PiNode is useless as soon as the type of its input
+ * is as narrow or narrower than the PiNode's type. The PiNode, and therefore also the scheduling
+ * restriction enforced by the anchor, will go away.
  */
 public class PiNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, Node.IterableNodeType, GuardingNode, Canonicalizable {
 
@@ -72,11 +76,9 @@
 
     @Override
     public ValueNode canonical(CanonicalizerTool tool) {
-        if (getGuard() == graph().start()) {
-            inferStamp();
-            if (stamp().equals(object().stamp())) {
-                return object();
-            }
+        inferStamp();
+        if (stamp().equals(object().stamp())) {
+            return object();
         }
         return this;
     }