1/*
2 * Copyright (c) 2002, 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25package sun.jvm.hotspot.interpreter;
26
27import sun.jvm.hotspot.oops.*;
28import sun.jvm.hotspot.utilities.*;
29
30public class BytecodeIf extends BytecodeJmp {
31  BytecodeIf(Method method, int bci) {
32    super(method, bci);
33  }
34
35  public int getTargetBCI() {
36    return bci() + javaShortAt(1);
37  }
38
39  public void verify() {
40    if (Assert.ASSERTS_ENABLED) {
41      Assert.that(isValid(), "check if");
42    }
43  }
44
45  public boolean isValid() {
46    int jcode = javaCode();
47    return (jcode >= Bytecodes._ifeq && jcode <= Bytecodes._if_acmpne) ||
48           jcode == Bytecodes._ifnull || jcode == Bytecodes._ifnonnull;
49  }
50
51  public static BytecodeIf at(Method method, int bci) {
52    BytecodeIf b = new BytecodeIf(method, bci);
53    if (Assert.ASSERTS_ENABLED) {
54      b.verify();
55    }
56    return b;
57  }
58
59  /** Like at, but returns null if the BCI is not at some ifxxx bytecode  */
60  public static BytecodeIf atCheck(Method method, int bci) {
61    BytecodeIf b = new BytecodeIf(method, bci);
62    return (b.isValid() ? b : null);
63  }
64
65  public static BytecodeIf at(BytecodeStream bcs) {
66    return new BytecodeIf(bcs.method(), bcs.bci());
67  }
68}
69