--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/Base.java	Wed Apr 27 11:50:44 2011 +0200
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2009, 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.c1x.ir;
+
+import com.sun.c1x.debug.*;
+import com.sun.cri.ci.*;
+
+/**
+ * The {@code Base} instruction represents the end of the entry block of the procedure that has
+ * both the standard entry and the OSR entry as successors.
+ *
+ * @author Ben L. Titzer
+ */
+public final class Base extends BlockEnd {
+
+    /**
+     * Constructs a new Base instruction.
+     * @param standardEntry the standard entrypoint block
+     * @param osrEntry the OSR entrypoint block
+     */
+    public Base(BlockBegin standardEntry, BlockBegin osrEntry) {
+        super(CiKind.Illegal, null, false);
+        assert osrEntry == null || osrEntry.isOsrEntry();
+        assert standardEntry.isStandardEntry();
+        if (osrEntry != null) {
+            successors.add(osrEntry);
+        }
+        successors.add(standardEntry);
+    }
+
+    /**
+     * Gets the standard entrypoint block.
+     * @return the standard entrypoint block
+     */
+    public BlockBegin standardEntry() {
+        return defaultSuccessor();
+    }
+
+    /**
+     * Gets the OSR entrypoint block, if it exists.
+     * @return the OSR entrypoint bock, if it exists; {@code null} otherwise
+     */
+    public BlockBegin osrEntry() {
+        return successors.size() < 2 ? null : successors.get(0);
+    }
+
+    @Override
+    public void accept(ValueVisitor v) {
+        v.visitBase(this);
+    }
+
+    @Override
+    public void print(LogStream out) {
+        out.print("std entry B").print(standardEntry().blockID);
+        if (successors().size() > 1) {
+            out.print(" osr entry B").print(osrEntry().blockID);
+        }
+    }
+}