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.dexgen.dex.code.form;
18
19import com.android.dexgen.dex.code.CstInsn;
20import com.android.dexgen.dex.code.DalvInsn;
21import com.android.dexgen.dex.code.InsnFormat;
22import com.android.dexgen.rop.code.RegisterSpecList;
23import com.android.dexgen.rop.cst.Constant;
24import com.android.dexgen.rop.cst.CstLiteralBits;
25import com.android.dexgen.util.AnnotatedOutput;
26
27/**
28 * Instruction format {@code 22s}. See the instruction format spec
29 * for details.
30 */
31public final class Form22s extends InsnFormat {
32    /** {@code non-null;} unique instance of this class */
33    public static final InsnFormat THE_ONE = new Form22s();
34
35    /**
36     * Constructs an instance. This class is not publicly
37     * instantiable. Use {@link #THE_ONE}.
38     */
39    private Form22s() {
40        // This space intentionally left blank.
41    }
42
43    /** {@inheritDoc} */
44    @Override
45    public String insnArgString(DalvInsn insn) {
46        RegisterSpecList regs = insn.getRegisters();
47        CstLiteralBits value = (CstLiteralBits) ((CstInsn) insn).getConstant();
48
49        return regs.get(0).regString() + ", " + regs.get(1).regString()
50            + ", " + literalBitsString(value);
51    }
52
53    /** {@inheritDoc} */
54    @Override
55    public String insnCommentString(DalvInsn insn, boolean noteIndices) {
56        CstLiteralBits value = (CstLiteralBits) ((CstInsn) insn).getConstant();
57        return literalBitsComment(value, 16);
58    }
59
60    /** {@inheritDoc} */
61    @Override
62    public int codeSize() {
63        return 2;
64    }
65
66    /** {@inheritDoc} */
67    @Override
68    public boolean isCompatible(DalvInsn insn) {
69        RegisterSpecList regs = insn.getRegisters();
70        if (!((insn instanceof CstInsn) &&
71              (regs.size() == 2) &&
72              unsignedFitsInNibble(regs.get(0).getReg()) &&
73              unsignedFitsInNibble(regs.get(1).getReg()))) {
74            return false;
75        }
76
77        CstInsn ci = (CstInsn) insn;
78        Constant cst = ci.getConstant();
79
80        if (!(cst instanceof CstLiteralBits)) {
81            return false;
82        }
83
84        CstLiteralBits cb = (CstLiteralBits) cst;
85
86        return cb.fitsInInt() && signedFitsInShort(cb.getIntBits());
87    }
88
89    /** {@inheritDoc} */
90    @Override
91    public InsnFormat nextUp() {
92        return null;
93    }
94
95    /** {@inheritDoc} */
96    @Override
97    public void writeTo(AnnotatedOutput out, DalvInsn insn) {
98        RegisterSpecList regs = insn.getRegisters();
99        int value =
100            ((CstLiteralBits) ((CstInsn) insn).getConstant()).getIntBits();
101
102        write(out,
103              opcodeUnit(insn,
104                         makeByte(regs.get(0).getReg(), regs.get(1).getReg())),
105              (short) value);
106    }
107}
108