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.
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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
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23  */
24 
25 package sun.jvm.hotspot.interpreter;
26 
27 import sun.jvm.hotspot.oops.*;
28 import sun.jvm.hotspot.utilities.*;
29 
30 public class BytecodeIf extends BytecodeJmp {
BytecodeIf(Method method, int bci)31   BytecodeIf(Method method, int bci) {
32     super(method, bci);
33   }
34 
getTargetBCI()35   public int getTargetBCI() {
36     return bci() + javaShortAt(1);
37   }
38 
verify()39   public void verify() {
40     if (Assert.ASSERTS_ENABLED) {
41       Assert.that(isValid(), "check if");
42     }
43   }
44 
isValid()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 
at(Method method, int bci)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  */
atCheck(Method method, int bci)60   public static BytecodeIf atCheck(Method method, int bci) {
61     BytecodeIf b = new BytecodeIf(method, bci);
62     return (b.isValid() ? b : null);
63   }
64 
at(BytecodeStream bcs)65   public static BytecodeIf at(BytecodeStream bcs) {
66     return new BytecodeIf(bcs.method(), bcs.bci());
67   }
68 }
69