# HG changeset patch
# User Paul Woegerer <paul.woegerer@oracle.com>
# Date 1423823945 -3600
# Node ID af4a778b3ce683c7ec6e3f09db8ba568b3293a7b
# Parent  ff5b7f5063a3b8c64682ebe0715771fc454a7588
Allow WordCastNode to be reduced to constant node (for constant input)

diff -r ff5b7f5063a3 -r af4a778b3ce6 graal/com.oracle.graal.word/src/com/oracle/graal/word/nodes/WordCastNode.java
--- a/graal/com.oracle.graal.word/src/com/oracle/graal/word/nodes/WordCastNode.java	Fri Feb 13 11:33:00 2015 +0100
+++ b/graal/com.oracle.graal.word/src/com/oracle/graal/word/nodes/WordCastNode.java	Fri Feb 13 11:39:05 2015 +0100
@@ -65,6 +65,17 @@
             /* If the cast is unused, it can be eliminated. */
             return input;
         }
+
+        assert !stamp().isCompatible(input.stamp());
+        if (input.isConstant()) {
+            /* Null pointers are uncritical for GC, so they can be constant folded. */
+            if (input.asJavaConstant().isNull()) {
+                return ConstantNode.forIntegerStamp(stamp(), 0);
+            } else if (input.asJavaConstant().getKind().isNumericInteger() && input.asJavaConstant().asLong() == 0) {
+                return ConstantNode.forConstant(stamp(), JavaConstant.NULL_POINTER, tool.getMetaAccess());
+            }
+        }
+
         return this;
     }