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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 22b}. See the instruction format spec
     30  * for details.
     31  */
     32 public 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