Instruction11n.java revision cb83d271e5485aa85ec7b8b3dc7b6e01417e1e43 
1/*
2 * [The "BSD licence"]
3 * Copyright (c) 2009 Ben Gruver
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29package org.jf.dexlib.Code.Format;
30
31import org.jf.dexlib.DexFile;
32import org.jf.dexlib.IndexedItem;
33import org.jf.dexlib.Code.Instruction;
34import org.jf.dexlib.Code.Opcode;
35import org.jf.dexlib.Util.NumberUtils;
36
37public class Instruction11n extends Instruction
38{
39    public static final InstructionFactory Factory = new Factory();
40
41    public Instruction11n(DexFile dexFile, Opcode opcode, byte regA, byte litB) {
42        super(dexFile, opcode, (IndexedItem)null);
43
44        if (regA >= 1<<4) {
45            throw new RuntimeException("The register number must be less than v16");
46        }
47
48        if (litB < -(1<<3) ||
49            litB >= 1<<3) {
50            throw new RuntimeException("The literal value must be between -8 and 7 inclusive");
51        }
52
53        encodedInstruction = new byte[2];
54        encodedInstruction[0] = opcode.value;
55        encodedInstruction[1] = (byte)((litB << 4) | regA);
56    }
57
58    private Instruction11n(DexFile dexFile, Opcode opcode, byte[] rest) {
59        super(dexFile, opcode, rest);
60    }
61
62    private Instruction11n() {
63    }
64
65    public Format getFormat() {
66        return Format.Format11n;
67    }
68
69    protected Instruction makeClone() {
70        return new Instruction11n();
71    }
72
73    private static class Factory implements Instruction.InstructionFactory {
74        public Instruction makeInstruction(DexFile dexFile, Opcode opcode, byte[] rest) {
75            return new Instruction11n(dexFile, opcode, rest);
76        }
77    }
78
79
80    public byte getRegister() {
81        return NumberUtils.decodeLowUnsignedNibble(encodedInstruction[1]);
82    }
83
84    public byte getLiteral() {
85        return NumberUtils.decodeHighSignedNibble(encodedInstruction[1]);
86    }
87}