1 /*
2  * Copyright (c) 2002, 2005, 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 
25 package sun.jvm.hotspot.interpreter;
26 
27 import sun.jvm.hotspot.oops.*;
28 import sun.jvm.hotspot.utilities.*;
29 
30 public class BytecodeIinc extends BytecodeWideable {
BytecodeIinc(Method method, int bci)31   BytecodeIinc(Method method, int bci) {
32     super(method, bci);
33   }
34 
getIncrement()35   public int getIncrement() {
36     // increment is signed
37     return (isWide()) ? (int) javaShortAt(3) : (int) javaByteAt(2);
38   }
39 
verify()40   public void verify() {
41     if (Assert.ASSERTS_ENABLED) {
42       Assert.that(isValid(), "check iinc");
43     }
44   }
45 
isValid()46   public boolean isValid() {
47     return javaCode() == Bytecodes._iinc;
48   }
49 
at(Method method, int bci)50   public static BytecodeIinc at(Method method, int bci) {
51     BytecodeIinc b = new BytecodeIinc(method, bci);
52     if (Assert.ASSERTS_ENABLED) {
53       b.verify();
54     }
55     return b;
56   }
57 
58   /** Like at, but returns null if the BCI is not at iinc  */
atCheck(Method method, int bci)59   public static BytecodeIinc atCheck(Method method, int bci) {
60     BytecodeIinc b = new BytecodeIinc(method, bci);
61     return (b.isValid() ? b : null);
62   }
63 
at(BytecodeStream bcs)64   public static BytecodeIinc at(BytecodeStream bcs) {
65     return new BytecodeIinc(bcs.method(), bcs.bci());
66   }
67 
toString()68   public String toString() {
69     StringBuffer buf = new StringBuffer();
70     buf.append("iinc");
71     buf.append(spaces);
72     buf.append('#');
73     buf.append(Integer.toString(getLocalVarIndex()));
74     buf.append(" by ");
75     buf.append(Integer.toString(getIncrement()));
76     return buf.toString();
77   }
78 }
79