--- a/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/gen/DebugInfoBuilder.java	Thu Jan 31 17:45:25 2013 +0100
+++ b/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/gen/DebugInfoBuilder.java	Thu Jan 31 17:45:41 2013 +0100
@@ -148,6 +148,7 @@
                 throw new GraalInternalError("no mapping found for virtual object %s", obj);
             }
             if (state instanceof MaterializedObjectState) {
+                assert !(((MaterializedObjectState) state).materializedValue() instanceof VirtualObjectNode);
                 return toValue(((MaterializedObjectState) state).materializedValue());
             } else {
                 assert obj.entryCount() == 0 || state instanceof VirtualObjectState || obj instanceof BoxedVirtualObjectNode;

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/NewArrayNode.java	Thu Jan 31 17:45:25 2013 +0100
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/NewArrayNode.java	Thu Jan 31 17:45:41 2013 +0100
@@ -31,7 +31,7 @@
 /**
  * The {@code NewArrayNode} class is the base of all instructions that allocate arrays.
  */
-public abstract class NewArrayNode extends FixedWithNextNode implements Lowerable, VirtualizableAllocation, ArrayLengthProvider {
+public abstract class NewArrayNode extends FixedWithNextNode implements Canonicalizable, Lowerable, VirtualizableAllocation, ArrayLengthProvider {
 
     @Input private ValueNode length;
     private final ResolvedJavaType elementType;
@@ -100,6 +100,15 @@
     }
 
     @Override
+    public ValueNode canonical(CanonicalizerTool tool) {
+        if (usages().isEmpty() && length.integerStamp().isPositive()) {
+            return null;
+        } else {
+            return this;
+        }
+    }
+
+    @Override
     public void lower(LoweringTool tool) {
         tool.getRuntime().lower(this, tool);
     }

--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/NewInstanceNode.java	Thu Jan 31 17:45:25 2013 +0100
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/NewInstanceNode.java	Thu Jan 31 17:45:41 2013 +0100
@@ -33,7 +33,7 @@
  * The {@code NewInstanceNode} represents the allocation of an instance class object.
  */
 @NodeInfo(nameTemplate = "New {p#instanceClass/s}")
-public final class NewInstanceNode extends FixedWithNextNode implements VirtualizableAllocation, Lowerable, Node.IterableNodeType {
+public final class NewInstanceNode extends FixedWithNextNode implements Node.IterableNodeType, Canonicalizable, Lowerable, VirtualizableAllocation {
 
     private final ResolvedJavaType instanceClass;
     private final boolean fillContents;
@@ -78,6 +78,15 @@
     }
 
     @Override
+    public ValueNode canonical(CanonicalizerTool tool) {
+        if (usages().isEmpty()) {
+            return null;
+        } else {
+            return this;
+        }
+    }
+
+    @Override
     public void lower(LoweringTool tool) {
         tool.getRuntime().lower(this, tool);
     }

--- a/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/nodes/MaterializeObjectNode.java	Thu Jan 31 17:45:25 2013 +0100
+++ b/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/nodes/MaterializeObjectNode.java	Thu Jan 31 17:45:41 2013 +0100
@@ -54,10 +54,11 @@
         return ConstantNode.forInt(values.size(), graph());
     }
 
-    @Override
-    public void lower(LoweringTool tool) {
-        StructuredGraph graph = (StructuredGraph) graph();
-
+    /**
+     * @return true if the object that will be created is without locks and has only entries that
+     *         are {@link Constant#defaultForKind(Kind)}, false otherwise.
+     */
+    public boolean isDefault() {
         boolean defaultEntries = true;
         if (lockCount > 0) {
             defaultEntries = false;
@@ -69,6 +70,14 @@
                 }
             }
         }
+        return defaultEntries;
+    }
+
+    @Override
+    public void lower(LoweringTool tool) {
+        StructuredGraph graph = (StructuredGraph) graph();
+
+        boolean defaultEntries = isDefault();
 
         if (virtualObject instanceof VirtualInstanceNode) {
             VirtualInstanceNode virtual = (VirtualInstanceNode) virtualObject;