# HG changeset patch
# User Lukas Stadler <lukas.stadler@oracle.com>
# Date 1427716799 -7200
# Node ID a7ee2e1f0d4ece014306fb5189df56a1e03e9ef1
# Parent  a875af927be865d7f607f2d0d3bff181cdbcdf87
remove UnboxNodes without usages (if object is non-null)

diff -r a875af927be8 -r a7ee2e1f0d4e graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/UnboxNode.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/UnboxNode.java	Mon Mar 30 11:59:58 2015 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/UnboxNode.java	Mon Mar 30 13:59:59 2015 +0200
@@ -29,6 +29,7 @@
 import com.oracle.graal.nodeinfo.*;
 import com.oracle.graal.nodes.*;
 import com.oracle.graal.nodes.spi.*;
+import com.oracle.graal.nodes.type.*;
 
 @NodeInfo
 public final class UnboxNode extends FixedWithNextNode implements Virtualizable, Lowerable, Canonicalizable.Unary<ValueNode> {
@@ -78,6 +79,9 @@
 
     @Override
     public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {
+        if (hasNoUsages() && StampTool.isPointerNonNull(forValue)) {
+            return null;
+        }
         ValueNode synonym = findSynonym(tool.getMetaAccess(), tool.getConstantReflection(), forValue, boxingKind);
         if (synonym != null) {
             return synonym;
diff -r a875af927be8 -r a7ee2e1f0d4e graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/type/StampTool.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/type/StampTool.java	Mon Mar 30 11:59:58 2015 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/type/StampTool.java	Mon Mar 30 13:59:59 2015 +0200
@@ -122,7 +122,7 @@
 
     /**
      * Checks whether this {@link Stamp} represents a {@linkplain Stamp#isLegal() legal} pointer
-     * stamp whose values known to be always null.
+     * stamp whose values are known to never be null.
      *
      * @param stamp the stamp to check
      * @return true if this stamp represents a legal object stamp whose values are known to be