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.DalvInsn; 20import com.android.dx.dex.code.InsnFormat; 21import com.android.dx.dex.code.TargetInsn; 22import com.android.dx.rop.code.RegisterSpecList; 23import com.android.dx.util.AnnotatedOutput; 24import java.util.BitSet; 25 26/** 27 * Instruction format {@code 22t}. See the instruction format spec 28 * for details. 29 */ 30public final class Form22t extends InsnFormat { 31 /** {@code non-null;} unique instance of this class */ 32 public static final InsnFormat THE_ONE = new Form22t(); 33 34 /** 35 * Constructs an instance. This class is not publicly 36 * instantiable. Use {@link #THE_ONE}. 37 */ 38 private Form22t() { 39 // This space intentionally left blank. 40 } 41 42 /** {@inheritDoc} */ 43 @Override 44 public String insnArgString(DalvInsn insn) { 45 RegisterSpecList regs = insn.getRegisters(); 46 return regs.get(0).regString() + ", " + regs.get(1).regString() + 47 ", " + branchString(insn); 48 } 49 50 /** {@inheritDoc} */ 51 @Override 52 public String insnCommentString(DalvInsn insn, boolean noteIndices) { 53 return branchComment(insn); 54 } 55 56 /** {@inheritDoc} */ 57 @Override 58 public int codeSize() { 59 return 2; 60 } 61 62 /** {@inheritDoc} */ 63 @Override 64 public boolean isCompatible(DalvInsn insn) { 65 RegisterSpecList regs = insn.getRegisters(); 66 67 if (!((insn instanceof TargetInsn) && 68 (regs.size() == 2) && 69 unsignedFitsInNibble(regs.get(0).getReg()) && 70 unsignedFitsInNibble(regs.get(1).getReg()))) { 71 return false; 72 } 73 74 TargetInsn ti = (TargetInsn) insn; 75 return ti.hasTargetOffset() ? branchFits(ti) : true; 76 } 77 78 /** {@inheritDoc} */ 79 @Override 80 public BitSet compatibleRegs(DalvInsn insn) { 81 RegisterSpecList regs = insn.getRegisters(); 82 BitSet bits = new BitSet(2); 83 84 bits.set(0, unsignedFitsInNibble(regs.get(0).getReg())); 85 bits.set(1, unsignedFitsInNibble(regs.get(1).getReg())); 86 return bits; 87 } 88 89 /** {@inheritDoc} */ 90 @Override 91 public boolean branchFits(TargetInsn insn) { 92 int offset = insn.getTargetOffset(); 93 94 // Note: A zero offset would fit, but it is prohibited by the spec. 95 return (offset != 0) && signedFitsInShort(offset); 96 } 97 98 /** {@inheritDoc} */ 99 @Override 100 public void writeTo(AnnotatedOutput out, DalvInsn insn) { 101 RegisterSpecList regs = insn.getRegisters(); 102 int offset = ((TargetInsn) insn).getTargetOffset(); 103 104 write(out, 105 opcodeUnit(insn, 106 makeByte(regs.get(0).getReg(), regs.get(1).getReg())), 107 (short) offset); 108 } 109} 110