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      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 
     17 package com.android.dx.dex.code.form;
     18 
     19 import com.android.dx.dex.code.DalvInsn;
     20 import com.android.dx.dex.code.InsnFormat;
     21 import com.android.dx.dex.code.SimpleInsn;
     22 import com.android.dx.rop.code.RegisterSpecList;
     23 import com.android.dx.util.AnnotatedOutput;
     24 
     25 import java.util.BitSet;
     26 
     27 /**
     28  * Instruction format {@code 23x}. See the instruction format spec
     29  * for details.
     30  */
     31 public final class Form23x extends InsnFormat {
     32     /** {@code non-null;} unique instance of this class */
     33     public static final InsnFormat THE_ONE = new Form23x();
     34 
     35     /**
     36      * Constructs an instance. This class is not publicly
     37      * instantiable. Use {@link #THE_ONE}.
     38      */
     39     private Form23x() {
     40         // This space intentionally left blank.
     41     }
     42 
     43     /** {@inheritDoc} */
     44     @Override
     45     public String insnArgString(DalvInsn insn) {
     46         RegisterSpecList regs = insn.getRegisters();
     47         return regs.get(0).regString() + ", " + regs.get(1).regString() +
     48             ", " + regs.get(2).regString();
     49     }
     50 
     51     /** {@inheritDoc} */
     52     @Override
     53     public String insnCommentString(DalvInsn insn, boolean noteIndices) {
     54         // This format has no comment.
     55         return "";
     56     }
     57 
     58     /** {@inheritDoc} */
     59     @Override
     60     public int codeSize() {
     61         return 2;
     62     }
     63 
     64     /** {@inheritDoc} */
     65     @Override
     66     public boolean isCompatible(DalvInsn insn) {
     67         RegisterSpecList regs = insn.getRegisters();
     68 
     69         return (insn instanceof SimpleInsn) &&
     70             (regs.size() == 3) &&
     71             unsignedFitsInByte(regs.get(0).getReg()) &&
     72             unsignedFitsInByte(regs.get(1).getReg()) &&
     73             unsignedFitsInByte(regs.get(2).getReg());
     74     }
     75 
     76     /** {@inheritDoc} */
     77     @Override
     78     public BitSet compatibleRegs(DalvInsn insn) {
     79         RegisterSpecList regs = insn.getRegisters();
     80         BitSet bits = new BitSet(3);
     81 
     82         bits.set(0, unsignedFitsInByte(regs.get(0).getReg()));
     83         bits.set(1, unsignedFitsInByte(regs.get(1).getReg()));
     84         bits.set(2, unsignedFitsInByte(regs.get(2).getReg()));
     85         return bits;
     86     }
     87 
     88     /** {@inheritDoc} */
     89     @Override
     90     public void writeTo(AnnotatedOutput out, DalvInsn insn) {
     91         RegisterSpecList regs = insn.getRegisters();
     92         write(out,
     93               opcodeUnit(insn, regs.get(0).getReg()),
     94               codeUnit(regs.get(1).getReg(), regs.get(2).getReg()));
     95     }
     96 }
     97