# HG changeset patch
# User Gilles Duboscq <duboscq@ssw.jku.at>
# Date 1381761651 -7200
# Node ID 28d80a9260cdc955a9d3361fd73c4fc2377ff7b6
# Parent  1d2d7924033ac2e5d5e806f26bcf9bf066335738
During CheckCast lowering, if null was never seen and a guard is created for the null case, the instanceof should be done on a non-null value.

diff -r 1d2d7924033a -r 28d80a9260cd graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/CheckCastNode.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/CheckCastNode.java	Mon Oct 14 15:52:24 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/java/CheckCastNode.java	Mon Oct 14 16:40:51 2013 +0200
@@ -91,13 +91,12 @@
      * 2: B b = guardingPi(a instanceof B, a, stamp(B, non-null))
      * </pre>
      * 
-     * Note: we use {@link Graph#add} as opposed to {@link Graph#unique} for the new
+     * Note: we use {@link Graph#addWithoutUnique} as opposed to {@link Graph#unique} for the new
      * {@link InstanceOfNode} to maintain the invariant checked by
      * {@code LoweringPhase.checkUsagesAreScheduled()}.
      */
     @Override
     public void lower(LoweringTool tool) {
-        InstanceOfNode typeTest = graph().addWithoutUnique(new InstanceOfNode(type, object, profile));
         Stamp stamp = StampFactory.declared(type);
         if (stamp() instanceof ObjectStamp && object().stamp() instanceof ObjectStamp) {
             stamp = ((ObjectStamp) object().stamp()).castTo((ObjectStamp) stamp);
@@ -108,17 +107,20 @@
             condition = LogicConstantNode.contradiction(graph());
             stamp = StampFactory.declared(type);
         } else if (ObjectStamp.isObjectNonNull(object)) {
-            condition = typeTest;
+            condition = graph().addWithoutUnique(new InstanceOfNode(type, object, profile));
         } else {
             if (profile != null && profile.getNullSeen() == TriState.FALSE) {
-                FixedGuardNode nullGuard = graph().add(new FixedGuardNode(graph().unique(new IsNullNode(object)), UnreachedCode, DeoptimizationAction.InvalidateReprofile, true));
-                graph().addBeforeFixed(this, nullGuard);
+                FixedGuardNode nullCheck = graph().add(new FixedGuardNode(graph().unique(new IsNullNode(object)), UnreachedCode, InvalidateReprofile, true));
+                PiNode nullGuarded = graph().unique(new PiNode(object, object().stamp().join(StampFactory.objectNonNull()), nullCheck));
+                InstanceOfNode typeTest = graph().addWithoutUnique(new InstanceOfNode(type, nullGuarded, profile));
+                graph().addBeforeFixed(this, nullCheck);
                 condition = typeTest;
                 stamp = stamp.join(StampFactory.objectNonNull());
-                nullGuard.lower(tool);
+                nullCheck.lower(tool);
             } else {
                 // TODO (ds) replace with probability of null-seen when available
                 double shortCircuitProbability = NOT_FREQUENT_PROBABILITY;
+                InstanceOfNode typeTest = graph().addWithoutUnique(new InstanceOfNode(type, object, profile));
                 condition = LogicNode.or(graph().unique(new IsNullNode(object)), typeTest, shortCircuitProbability);
             }
         }