Mercurial > hg > truffle
diff agent/src/share/classes/sun/jvm/hotspot/oops/BitData.java @ 3945:8ed53447f690
Merge
author | iveresov |
---|---|
date | Thu, 15 Sep 2011 12:44:09 -0700 |
parents | f6f3bb0ee072 |
children | 79f492f184d0 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/agent/src/share/classes/sun/jvm/hotspot/oops/BitData.java Thu Sep 15 12:44:09 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"); + } +}