--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/oops/BitData.java	Sun Sep 11 14:48:24 2011 -0700
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package sun.jvm.hotspot.oops;
+
+import java.io.*;
+import java.util.*;
+import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.runtime.*;
+import sun.jvm.hotspot.types.*;
+import sun.jvm.hotspot.utilities.*;
+
+// BitData
+//
+// A BitData holds a flag or two in its header.
+public class BitData extends ProfileData {
+
+  // nullSeen:
+  //  saw a null operand (cast/aastore/instanceof)
+  static final int nullSeenFlag              = DataLayout.firstFlag + 0;
+  static final int bitCellCount = 0;
+
+  public BitData(DataLayout layout) {
+    super(layout);
+  }
+
+  static int staticCellCount() {
+    return bitCellCount;
+  }
+
+  public int cellCount() {
+    return staticCellCount();
+  }
+
+  // Accessor
+
+  // The nullSeen flag bit is specially known to the interpreter.
+  // Consulting it allows the compiler to avoid setting up nullCheck traps.
+  boolean nullSeen()     { return flagAt(nullSeenFlag); }
+
+  // Code generation support
+  // static int nullSeenByteConstant() {
+  //   return flagNumberToByteConstant(nullSeenFlag);
+  // }
+
+  static int bitDataSize() {
+    return cellOffset(bitCellCount);
+  }
+
+  public void printDataOn(PrintStream st) {
+    printShared(st, "BitData");
+  }
+}