--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.max.asmdis/src/com/sun/max/asm/ppc/ZeroOrRegister.java	Sat Dec 17 19:59:18 2011 +0100
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2007, 2011, 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.sun.max.asm.ppc;
+
+import com.sun.max.asm.*;
+import com.sun.max.util.*;
+
+/**
+ * The super type of all the {@link GPR General Purpose Registers} and the constant {@link Zero#ZERO}.
+ */
+public abstract class ZeroOrRegister extends AbstractSymbolicArgument {
+
+    ZeroOrRegister(String name, int value) {
+        super(name, value);
+    }
+
+    /**
+     * Determines if this register specifier is outside the range of registers
+     * {@code [target .. target+n]} where the range
+     * wraps at 32.
+     */
+    public boolean isOutsideRegisterRange(GPR target, int n) {
+        final int rt = target.value();
+        final int ra = value();
+        final int numRegs = (n + 3) / 4;
+        final int lastReg = (rt + numRegs - 1) % 32;
+        final boolean wrapsAround = lastReg < rt;
+        if (wrapsAround) {
+            return lastReg < ra && ra < rt;
+        }
+        return ra < rt || lastReg < ra;
+    }
+
+    public static Symbolizer<ZeroOrRegister> symbolizer() {
+        if (symbolizer == null) {
+            symbolizer = Symbolizer.Static.fromList(ZeroOrRegister.class, GPR.GPR_SYMBOLIZER, Zero.ZERO);
+        }
+        return symbolizer;
+    }
+
+    // This must be lazily constructed to avoid dependency on the GPR class initializer
+    private static Symbolizer<ZeroOrRegister> symbolizer;
+
+}