| /* |
| * Copyright (C) 2007 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.dexgen.dex.code.form; |
| |
| import com.android.dexgen.dex.code.CstInsn; |
| import com.android.dexgen.dex.code.DalvInsn; |
| import com.android.dexgen.dex.code.InsnFormat; |
| import com.android.dexgen.rop.code.RegisterSpec; |
| import com.android.dexgen.rop.code.RegisterSpecList; |
| import com.android.dexgen.rop.cst.Constant; |
| import com.android.dexgen.rop.cst.CstMethodRef; |
| import com.android.dexgen.rop.cst.CstType; |
| import com.android.dexgen.rop.type.Type; |
| import com.android.dexgen.util.AnnotatedOutput; |
| |
| /** |
| * Instruction format {@code 35c}. See the instruction format spec |
| * for details. |
| */ |
| public final class Form35c extends InsnFormat { |
| /** {@code non-null;} unique instance of this class */ |
| public static final InsnFormat THE_ONE = new Form35c(); |
| |
| /** Maximal number of operands */ |
| private static final int MAX_NUM_OPS = 5; |
| |
| /** |
| * Constructs an instance. This class is not publicly |
| * instantiable. Use {@link #THE_ONE}. |
| */ |
| private Form35c() { |
| // This space intentionally left blank. |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public String insnArgString(DalvInsn insn) { |
| RegisterSpecList regs = explicitize(insn.getRegisters()); |
| return regListString(regs) + ", " + cstString(insn); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public String insnCommentString(DalvInsn insn, boolean noteIndices) { |
| if (noteIndices) { |
| return cstComment(insn); |
| } else { |
| return ""; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int codeSize() { |
| return 3; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean isCompatible(DalvInsn insn) { |
| if (!(insn instanceof CstInsn)) { |
| return false; |
| } |
| |
| CstInsn ci = (CstInsn) insn; |
| int cpi = ci.getIndex(); |
| |
| if (! unsignedFitsInShort(cpi)) { |
| return false; |
| } |
| |
| Constant cst = ci.getConstant(); |
| if (!((cst instanceof CstMethodRef) || |
| (cst instanceof CstType))) { |
| return false; |
| } |
| |
| RegisterSpecList regs = ci.getRegisters(); |
| return (wordCount(regs) >= 0); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public InsnFormat nextUp() { |
| return Form3rc.THE_ONE; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void writeTo(AnnotatedOutput out, DalvInsn insn) { |
| int cpi = ((CstInsn) insn).getIndex(); |
| RegisterSpecList regs = explicitize(insn.getRegisters()); |
| int sz = regs.size(); |
| int r0 = (sz > 0) ? regs.get(0).getReg() : 0; |
| int r1 = (sz > 1) ? regs.get(1).getReg() : 0; |
| int r2 = (sz > 2) ? regs.get(2).getReg() : 0; |
| int r3 = (sz > 3) ? regs.get(3).getReg() : 0; |
| int r4 = (sz > 4) ? regs.get(4).getReg() : 0; |
| |
| write(out, |
| opcodeUnit(insn, |
| makeByte(r4, sz)), // encode the fifth operand here |
| (short) cpi, |
| codeUnit(r0, r1, r2, r3)); |
| } |
| |
| /** |
| * Gets the number of words required for the given register list, where |
| * category-2 values count as two words. Return {@code -1} if the |
| * list requires more than five words or contains registers that need |
| * more than a nibble to identify them. |
| * |
| * @param regs {@code non-null;} the register list in question |
| * @return {@code >= -1;} the number of words required, or {@code -1} |
| * if the list couldn't possibly fit in this format |
| */ |
| private static int wordCount(RegisterSpecList regs) { |
| int sz = regs.size(); |
| |
| if (sz > MAX_NUM_OPS) { |
| // It can't possibly fit. |
| return -1; |
| } |
| |
| int result = 0; |
| |
| for (int i = 0; i < sz; i++) { |
| RegisterSpec one = regs.get(i); |
| result += one.getCategory(); |
| /* |
| * The check below adds (category - 1) to the register, to |
| * account for the fact that the second half of a |
| * category-2 register has to be represented explicitly in |
| * the result. |
| */ |
| if (!unsignedFitsInNibble(one.getReg() + one.getCategory() - 1)) { |
| return -1; |
| } |
| } |
| |
| return (result <= MAX_NUM_OPS) ? result : -1; |
| } |
| |
| /** |
| * Returns a register list which is equivalent to the given one, |
| * except that it splits category-2 registers into two explicit |
| * entries. This returns the original list if no modification is |
| * required |
| * |
| * @param orig {@code non-null;} the original list |
| * @return {@code non-null;} the list with the described transformation |
| */ |
| private static RegisterSpecList explicitize(RegisterSpecList orig) { |
| int wordCount = wordCount(orig); |
| int sz = orig.size(); |
| |
| if (wordCount == sz) { |
| return orig; |
| } |
| |
| RegisterSpecList result = new RegisterSpecList(wordCount); |
| int wordAt = 0; |
| |
| for (int i = 0; i < sz; i++) { |
| RegisterSpec one = orig.get(i); |
| result.set(wordAt, one); |
| if (one.getCategory() == 2) { |
| result.set(wordAt + 1, |
| RegisterSpec.make(one.getReg() + 1, Type.VOID)); |
| wordAt += 2; |
| } else { |
| wordAt++; |
| } |
| } |
| |
| result.setImmutable(); |
| return result; |
| } |
| } |