3939
|
1 /*
|
|
2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
|
|
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
4 *
|
|
5 * This code is free software; you can redistribute it and/or modify it
|
|
6 * under the terms of the GNU General Public License version 2 only, as
|
|
7 * published by the Free Software Foundation.
|
|
8 *
|
|
9 * This code is distributed in the hope that it will be useful, but WITHOUT
|
|
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
12 * version 2 for more details (a copy is included in the LICENSE file that
|
|
13 * accompanied this code).
|
|
14 *
|
|
15 * You should have received a copy of the GNU General Public License version
|
|
16 * 2 along with this work; if not, write to the Free Software Foundation,
|
|
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
18 *
|
|
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
20 * CA 95054 USA or visit www.sun.com if you need additional information or
|
|
21 * have any questions.
|
|
22 *
|
|
23 */
|
|
24
|
|
25 package sun.jvm.hotspot.oops;
|
|
26
|
|
27 import java.io.*;
|
|
28 import java.util.*;
|
|
29 import sun.jvm.hotspot.debugger.*;
|
|
30 import sun.jvm.hotspot.runtime.*;
|
|
31 import sun.jvm.hotspot.types.*;
|
|
32 import sun.jvm.hotspot.utilities.*;
|
|
33
|
|
34 // BitData
|
|
35 //
|
|
36 // A BitData holds a flag or two in its header.
|
|
37 public class BitData extends ProfileData {
|
|
38
|
|
39 // nullSeen:
|
|
40 // saw a null operand (cast/aastore/instanceof)
|
|
41 static final int nullSeenFlag = DataLayout.firstFlag + 0;
|
|
42 static final int bitCellCount = 0;
|
|
43
|
|
44 public BitData(DataLayout layout) {
|
|
45 super(layout);
|
|
46 }
|
|
47
|
|
48 static int staticCellCount() {
|
|
49 return bitCellCount;
|
|
50 }
|
|
51
|
|
52 public int cellCount() {
|
|
53 return staticCellCount();
|
|
54 }
|
|
55
|
|
56 // Accessor
|
|
57
|
|
58 // The nullSeen flag bit is specially known to the interpreter.
|
|
59 // Consulting it allows the compiler to avoid setting up nullCheck traps.
|
|
60 boolean nullSeen() { return flagAt(nullSeenFlag); }
|
|
61
|
|
62 // Code generation support
|
|
63 // static int nullSeenByteConstant() {
|
|
64 // return flagNumberToByteConstant(nullSeenFlag);
|
|
65 // }
|
|
66
|
|
67 static int bitDataSize() {
|
|
68 return cellOffset(bitCellCount);
|
|
69 }
|
|
70
|
|
71 public void printDataOn(PrintStream st) {
|
|
72 printShared(st, "BitData");
|
|
73 }
|
|
74 }
|