# HG changeset patch
# User Lukas Stadler <lukas.stadler@jku.at>
# Date 1336742273 -7200
# Node ID e4321a9bc0cb513e094441e177ebd0b19ed26481
# Parent  b6aaf6de4053e536acb75d94aede042138e020c2
use exactType and assumptions to canonicalize ReadHubNode

diff -r b6aaf6de4053 -r e4321a9bc0cb graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ReadHubNode.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ReadHubNode.java	Fri May 11 15:17:17 2012 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ReadHubNode.java	Fri May 11 15:17:53 2012 +0200
@@ -26,9 +26,11 @@
 import com.oracle.graal.nodes.*;
 import com.oracle.graal.nodes.spi.*;
 import com.oracle.graal.nodes.type.*;
+import com.oracle.max.cri.ri.*;
+import com.oracle.max.cri.ri.RiType.*;
 
 // TODO (chaeubl) this should be a FloatingNode but Lowering is not possible in that case
-public final class ReadHubNode extends FixedWithNextNode implements Lowerable {
+public final class ReadHubNode extends FixedWithNextNode implements Lowerable, Canonicalizable {
     @Input private ValueNode object;
 
     public ValueNode object() {
@@ -44,4 +46,20 @@
     public void lower(CiLoweringTool tool) {
         tool.getRuntime().lower(this, tool);
     }
+
+    @Override
+    public ValueNode canonical(CanonicalizerTool tool) {
+        RiResolvedType exactType = object.exactType();
+
+        if (exactType == null && tool.assumptions() != null && object.declaredType() != null) {
+            exactType = object.declaredType().uniqueConcreteSubtype();
+            if (exactType != null) {
+                tool.assumptions().recordConcreteSubtype(object.declaredType(), exactType);
+            }
+        }
+        if (exactType != null) {
+            return ConstantNode.forCiConstant(exactType.getEncoding(Representation.ObjectHub), tool.runtime(), graph());
+        }
+        return this;
+    }
 }