Form22b.java revision fe107fb6e3f308ac5174ebdc5a794ee880c741d9 
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.dx.dex.code.form;
18
19import com.android.dx.dex.code.CstInsn;
20import com.android.dx.dex.code.DalvInsn;
21import com.android.dx.dex.code.InsnFormat;
22import com.android.dx.rop.code.RegisterSpecList;
23import com.android.dx.rop.cst.Constant;
24import com.android.dx.rop.cst.CstLiteralBits;
25import com.android.dx.util.AnnotatedOutput;
26import java.util.BitSet;
27
28/**
29 * Instruction format {@code 22b}. See the instruction format spec
30 * for details.
31 */
32public final class Form22b extends InsnFormat {
33    /** {@code non-null;} unique instance of this class */
34    public static final InsnFormat THE_ONE = new Form22b();
35
36    /**
37     * Constructs an instance. This class is not publicly
38     * instantiable. Use {@link #THE_ONE}.
39     */
40    private Form22b() {
41        // This space intentionally left blank.
42    }
43
44    /** {@inheritDoc} */
45    @Override
46    public String insnArgString(DalvInsn insn) {
47        RegisterSpecList regs = insn.getRegisters();
48        CstLiteralBits value = (CstLiteralBits) ((CstInsn) insn).getConstant();
49
50        return regs.get(0).regString() + ", " + regs.get(1).regString() +
51            ", " + literalBitsString(value);
52    }
53
54    /** {@inheritDoc} */
55    @Override
56    public String insnCommentString(DalvInsn insn, boolean noteIndices) {
57        CstLiteralBits value = (CstLiteralBits) ((CstInsn) insn).getConstant();
58        return literalBitsComment(value, 8);
59    }
60
61    /** {@inheritDoc} */
62    @Override
63    public int codeSize() {
64        return 2;
65    }
66
67    /** {@inheritDoc} */
68    @Override
69    public boolean isCompatible(DalvInsn insn) {
70        RegisterSpecList regs = insn.getRegisters();
71        if (!((insn instanceof CstInsn) &&
72              (regs.size() == 2) &&
73              unsignedFitsInByte(regs.get(0).getReg()) &&
74              unsignedFitsInByte(regs.get(1).getReg()))) {
75            return false;
76        }
77
78        CstInsn ci = (CstInsn) insn;
79        Constant cst = ci.getConstant();
80
81        if (!(cst instanceof CstLiteralBits)) {
82            return false;
83        }
84
85        CstLiteralBits cb = (CstLiteralBits) cst;
86
87        return cb.fitsInInt() && signedFitsInByte(cb.getIntBits());
88    }
89
90    /** {@inheritDoc} */
91    @Override
92    public BitSet compatibleRegs(DalvInsn insn) {
93        RegisterSpecList regs = insn.getRegisters();
94        BitSet bits = new BitSet(2);
95
96        bits.set(0, unsignedFitsInByte(regs.get(0).getReg()));
97        bits.set(1, unsignedFitsInByte(regs.get(1).getReg()));
98        return bits;
99    }
100
101    /** {@inheritDoc} */
102    @Override
103    public void writeTo(AnnotatedOutput out, DalvInsn insn) {
104        RegisterSpecList regs = insn.getRegisters();
105        int value =
106            ((CstLiteralBits) ((CstInsn) insn).getConstant()).getIntBits();
107
108        write(out,
109              opcodeUnit(insn, regs.get(0).getReg()),
110              codeUnit(regs.get(1).getReg(), value & 0xff));
111    }
112}
113