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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.CstInsn;
     20 import com.android.dx.dex.code.DalvInsn;
     21 import com.android.dx.dex.code.InsnFormat;
     22 import com.android.dx.rop.code.RegisterSpecList;
     23 import com.android.dx.rop.cst.Constant;
     24 import com.android.dx.rop.cst.CstLiteralBits;
     25 import com.android.dx.util.AnnotatedOutput;
     26 import java.util.BitSet;
     27 
     28 /**
     29  * Instruction format {@code 21h}. See the instruction format spec
     30  * for details.
     31  */
     32 public final class Form21h extends InsnFormat {
     33     /** {@code non-null;} unique instance of this class */
     34     public static final InsnFormat THE_ONE = new Form21h();
     35 
     36     /**
     37      * Constructs an instance. This class is not publicly
     38      * instantiable. Use {@link #THE_ONE}.
     39      */
     40     private Form21h() {
     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() + ", " + literalBitsString(value);
     51     }
     52 
     53     /** {@inheritDoc} */
     54     @Override
     55     public String insnCommentString(DalvInsn insn, boolean noteIndices) {
     56         RegisterSpecList regs = insn.getRegisters();
     57         CstLiteralBits value = (CstLiteralBits) ((CstInsn) insn).getConstant();
     58 
     59         return
     60             literalBitsComment(value,
     61                     (regs.get(0).getCategory() == 1) ? 32 : 64);
     62     }
     63 
     64     /** {@inheritDoc} */
     65     @Override
     66     public int codeSize() {
     67         return 2;
     68     }
     69 
     70     /** {@inheritDoc} */
     71     @Override
     72     public boolean isCompatible(DalvInsn insn) {
     73         RegisterSpecList regs = insn.getRegisters();
     74         if (!((insn instanceof CstInsn) &&
     75               (regs.size() == 1) &&
     76               unsignedFitsInByte(regs.get(0).getReg()))) {
     77             return false;
     78         }
     79 
     80         CstInsn ci = (CstInsn) insn;
     81         Constant cst = ci.getConstant();
     82 
     83         if (!(cst instanceof CstLiteralBits)) {
     84             return false;
     85         }
     86 
     87         CstLiteralBits cb = (CstLiteralBits) cst;
     88 
     89         // Where the high bits are depends on the category of the target.
     90         if (regs.get(0).getCategory() == 1) {
     91             int bits = cb.getIntBits();
     92             return ((bits & 0xffff) == 0);
     93         } else {
     94             long bits = cb.getLongBits();
     95             return ((bits & 0xffffffffffffL) == 0);
     96         }
     97     }
     98 
     99     /** {@inheritDoc} */
    100     @Override
    101     public BitSet compatibleRegs(DalvInsn insn) {
    102         RegisterSpecList regs = insn.getRegisters();
    103         BitSet bits = new BitSet(1);
    104 
    105         bits.set(0, unsignedFitsInByte(regs.get(0).getReg()));
    106         return bits;
    107     }
    108 
    109     /** {@inheritDoc} */
    110     @Override
    111     public void writeTo(AnnotatedOutput out, DalvInsn insn) {
    112         RegisterSpecList regs = insn.getRegisters();
    113         CstLiteralBits cb = (CstLiteralBits) ((CstInsn) insn).getConstant();
    114         short bits;
    115 
    116         // Where the high bits are depends on the category of the target.
    117         if (regs.get(0).getCategory() == 1) {
    118             bits = (short) (cb.getIntBits() >>> 16);
    119         } else {
    120             bits = (short) (cb.getLongBits() >>> 48);
    121         }
    122 
    123         write(out, opcodeUnit(insn, regs.get(0).getReg()), bits);
    124     }
    125 }
    126