# HG changeset patch
# User Lukas Stadler <lukas.stadler@jku.at>
# Date 1375893224 -7200
# Node ID e428ffc7a0adb7086eed71c5fd0f180c29260ef2
# Parent  4f1aa732e60f00cb1071c271e1b1f079899e8b4e
new PureFunctionMacroNode

diff -r 4f1aa732e60f -r e428ffc7a0ad graal/com.oracle.graal.replacements/src/com/oracle/graal/replacements/nodes/PureFunctionMacroNode.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.replacements/src/com/oracle/graal/replacements/nodes/PureFunctionMacroNode.java	Wed Aug 07 18:33:44 2013 +0200
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.graal.replacements.nodes;
+
+import com.oracle.graal.api.meta.*;
+import com.oracle.graal.nodes.*;
+import com.oracle.graal.nodes.spi.*;
+
+/**
+ * This node class can be used to create {@link MacroNode}s for simple pure functions like
+ * {@link Object#getClass()} or {@link System#identityHashCode(Object)}.
+ */
+public abstract class PureFunctionMacroNode extends MacroNode implements Canonicalizable {
+
+    public PureFunctionMacroNode(Invoke invoke) {
+        super(invoke);
+    }
+
+    /**
+     * This method should return either a constant that represents the result of the function, or
+     * null if no such result could be determined.
+     */
+    protected abstract Constant evaluate(Constant param, MetaAccessProvider metaAccess);
+
+    public ValueNode canonical(CanonicalizerTool tool) {
+        if (usages().isEmpty()) {
+            return null;
+        } else {
+            ValueNode param = arguments.get(0);
+            if (param.isConstant()) {
+                Constant constant = evaluate(param.asConstant(), tool.runtime());
+                if (constant != null) {
+                    return ConstantNode.forConstant(constant, tool.runtime(), graph());
+                }
+            }
+        }
+        return this;
+    }
+}