Java Code Examples for com.android.dx.rop.code.RegisterSpec#getReg()

/** {@inheritDoc} */
@Override
public RegisterSpec map(RegisterSpec registerSpec) {
    if (registerSpec == null) return null;

    int reg = registerSpec.getReg();

    // For debugging: assert that the mapped types are compatible.
    if (DEBUG) {
        RegisterSpec newVersion = currentMapping[reg];
        if (newVersion.getBasicType() != Type.BT_VOID
                && registerSpec.getBasicFrameType()
                    != newVersion.getBasicFrameType()) {

            throw new RuntimeException(
                    "mapping registers of incompatible types! "
                    + registerSpec
                    + " " + currentMapping[reg]);
        }
    }

    return registerSpec.withReg(currentMapping[reg].getReg());
}
 

/**
 * Changes one of the insn's sources. New source should be of same type
 * and category.
 *
 * @param index {@code >=0;} index of source to change
 * @param newSpec spec for new source
 */
public final void changeOneSource(int index, RegisterSpec newSpec) {
    RegisterSpecList origSources = insn.getSources();
    int sz = origSources.size();
    RegisterSpecList newSources = new RegisterSpecList(sz);

    for (int i = 0; i < sz; i++) {
        newSources.set(i, i == index ? newSpec : origSources.get(i));
    }

    newSources.setImmutable();

    RegisterSpec origSpec = origSources.get(index);
    if (origSpec.getReg() != newSpec.getReg()) {
        /*
         * If the register remains unchanged, we're only changing
         * the type or local var name so don't update use list
         */
        getBlock().getParent().onSourceChanged(this, origSpec, newSpec);
    }

    insn = insn.withNewRegisters(getResult(), newSources);
}
 

/**
 * Makes a move instruction, appropriate and ideal for the given arguments.
 *
 * @param position {@code non-null;} source position information
 * @param dest {@code non-null;} destination register
 * @param src {@code non-null;} source register
 * @return {@code non-null;} an appropriately-constructed instance
 */
public static SimpleInsn makeMove(SourcePosition position,
        RegisterSpec dest, RegisterSpec src) {
    boolean category1 = dest.getCategory() == 1;
    boolean reference = dest.getType().isReference();
    int destReg = dest.getReg();
    int srcReg = src.getReg();
    Dop opcode;

    if ((srcReg | destReg) < 16) {
        opcode = reference ? Dops.MOVE_OBJECT :
            (category1 ? Dops.MOVE : Dops.MOVE_WIDE);
    } else if (destReg < 256) {
        opcode = reference ? Dops.MOVE_OBJECT_FROM16 :
            (category1 ? Dops.MOVE_FROM16 : Dops.MOVE_WIDE_FROM16);
    } else {
        opcode = reference ? Dops.MOVE_OBJECT_16 :
            (category1 ? Dops.MOVE_16 : Dops.MOVE_WIDE_16);
    }

    return new SimpleInsn(opcode, position,
                          RegisterSpecList.make(dest, src));
}
 

/**
 * Process a single instruction, looking for new objects resulting from
 * move result or move param.
 *
 * @param insn {@code non-null;} instruction to process
 */
private void processInsn(SsaInsn insn) {
    int op = insn.getOpcode().getOpcode();
    RegisterSpec result = insn.getResult();
    EscapeSet escSet;

    // Identify new objects
    if (op == RegOps.MOVE_RESULT_PSEUDO &&
            result.getTypeBearer().getBasicType() == Type.BT_OBJECT) {
        // Handle objects generated through move_result_pseudo
        escSet = processMoveResultPseudoInsn(insn);
        processRegister(result, escSet);
    } else if (op == RegOps.MOVE_PARAM &&
                  result.getTypeBearer().getBasicType() == Type.BT_OBJECT) {
        // Track method arguments that are objects
        escSet = new EscapeSet(result.getReg(), regCount, EscapeState.NONE);
        latticeValues.add(escSet);
        processRegister(result, escSet);
    } else if (op == RegOps.MOVE_RESULT &&
            result.getTypeBearer().getBasicType() == Type.BT_OBJECT) {
        // Track method return values that are objects
        escSet = new EscapeSet(result.getReg(), regCount, EscapeState.NONE);
        latticeValues.add(escSet);
        processRegister(result, escSet);
    }
}
 

/**
 * Records a debug (local variable) name for a specified register.
 *
 * @param ssaReg non-null named register spec in SSA name space
 */
private void setNameForSsaReg(RegisterSpec ssaReg) {
    int reg = ssaReg.getReg();
    LocalItem local = ssaReg.getLocalItem();

    ssaRegToLocalItems.ensureCapacity(reg + 1);
    while (ssaRegToLocalItems.size() <= reg) {
        ssaRegToLocalItems.add(null);
    }

    ssaRegToLocalItems.set(reg, local);
}
 

/**
 * Removes an instruction from use and def lists. For use during
 * instruction removal.
 *
 * @param insn {@code non-null;} insn to remove
 */
/*package*/ void onInsnRemoved(SsaInsn insn) {
    if (useList != null) {
        removeFromUseList(insn, insn.getSources());
    }

    RegisterSpec resultReg = insn.getResult();
    if (definitionList != null && resultReg != null) {
        definitionList[resultReg.getReg()] = null;
    }
}
 

/**
 * Removes an instruction from use and def lists. For use during
 * instruction removal.
 *
 * @param insn {@code non-null;} insn to remove
 */
/*package*/ void onInsnRemoved(SsaInsn insn) {
    if (useList != null) {
        removeFromUseList(insn, insn.getSources());
    }

    RegisterSpec resultReg = insn.getResult();
    if (definitionList != null && resultReg != null) {
        definitionList[resultReg.getReg()] = null;
    }
}
 

/**
 * Removes all instructions from every unreachable block.
 */
private void pruneDeadInstructions() {
    HashSet<SsaInsn> deletedInsns = new HashSet<SsaInsn>();

    ssaMeth.computeReachability();

    for (SsaBasicBlock block : ssaMeth.getBlocks()) {
        if (block.isReachable()) continue;

        // Prune instructions from unreachable blocks
        for (int i = 0; i < block.getInsns().size(); i++) {
            SsaInsn insn = block.getInsns().get(i);
            RegisterSpecList sources = insn.getSources();
            int sourcesSize = sources.size();

            // Delete this instruction completely if it has sources
            if (sourcesSize != 0) {
                deletedInsns.add(insn);
            }

            // Delete this instruction from all usage lists.
            for (int j = 0; j < sourcesSize; j++) {
                RegisterSpec source = sources.get(j);
                useList[source.getReg()].remove(insn);
            }

            // Remove this instruction result from the sources of any phis
            RegisterSpec result = insn.getResult();
            if (result == null) continue;
            for (SsaInsn use : useList[result.getReg()]) {
                if (use instanceof PhiInsn) {
                    PhiInsn phiUse = (PhiInsn) use;
                    phiUse.removePhiRegister(result);
                }
            }
        }
    }

    ssaMeth.deleteInsns(deletedInsns);
}
 

/** {@inheritDoc} */
@Override
public boolean isCompatible(DalvInsn insn) {
    if (!(insn instanceof SimpleInsn)) {
        return false;
    }

    RegisterSpecList regs = insn.getRegisters();
    RegisterSpec rs1;
    RegisterSpec rs2;

    switch (regs.size()) {
        case 2: {
            rs1 = regs.get(0);
            rs2 = regs.get(1);
            break;
        }
        case 3: {
            /*
             * This format is allowed for ops that are effectively
             * 3-arg but where the first two args are identical.
             */
            rs1 = regs.get(1);
            rs2 = regs.get(2);
            if (rs1.getReg() != regs.get(0).getReg()) {
                return false;
            }
            break;
        }
        default: {
            return false;
        }
    }

    return unsignedFitsInNibble(rs1.getReg()) &&
        unsignedFitsInNibble(rs2.getReg());
}
 

/**
 * Ends a local at the given address.
 *
 * @param address {@code >= 0;} the address
 * @param endedLocal {@code non-null;} spec representing the
 * local being ended
 * @param disposition reason for the end
 */
public void endLocal(int address, RegisterSpec endedLocal,
        Disposition disposition) {
    if (DEBUG) {
        System.err.printf("%04x end %s\n", address, endedLocal);
    }

    int regNum = endedLocal.getReg();

    endedLocal = filterSpec(endedLocal);
    aboutToProcess(address, regNum);

    int endAt = endIndices[regNum];

    if (endAt >= 0) {
        /*
         * The local in the given register is already ended.
         * Silently return without adding anything to the result.
         */
        return;
    }

    // Check for start and end at the same address.
    if (checkForEmptyRange(address, endedLocal)) {
        return;
    }

    add(address, disposition, endedLocal);
}
 

/** {@inheritDoc} */
@Override
public boolean isCompatible(DalvInsn insn) {
    if (!(insn instanceof CstInsn)) {
        return false;
    }

    RegisterSpecList regs = insn.getRegisters();
    RegisterSpec reg;

    switch (regs.size()) {
        case 1: {
            reg = regs.get(0);
            break;
        }
        case 2: {
            /*
             * This format is allowed for ops that are effectively
             * 2-arg but where the two args are identical.
             */
            reg = regs.get(0);
            if (reg.getReg() != regs.get(1).getReg()) {
                return false;
            }
            break;
        }
        default: {
            return false;
        }
    }

    if (!unsignedFitsInByte(reg.getReg())) {
        return false;
    }

    CstInsn ci = (CstInsn) insn;
    int cpi = ci.getIndex();
    Constant cst = ci.getConstant();

    if (! unsignedFitsInShort(cpi)) {
        return false;
    }

    return cst instanceof CstType ||
        cst instanceof CstFieldRef ||
        cst instanceof CstString ||
        cst instanceof CstMethodHandle ||
        cst instanceof CstProtoRef;
}
 

/**
 * Adds a move instruction to the end of this basic block, just
 * before the last instruction. If the result of the final instruction
 * is the source in question, then the move is placed at the beginning of
 * the primary successor block. This is for unversioned registers.
 *
 * @param result move destination
 * @param source move source
 */
public void addMoveToEnd(RegisterSpec result, RegisterSpec source) {

    if (result.getReg() == source.getReg()) {
        // Sometimes we end up with no-op moves. Ignore them here.
        return;
    }

    /*
     * The last Insn has to be a normal SSA insn: a phi can't branch
     * or return or cause an exception, etc.
     */
    NormalSsaInsn lastInsn;
    lastInsn = (NormalSsaInsn)insns.get(insns.size()-1);

    if (lastInsn.getResult() != null || lastInsn.getSources().size() > 0) {
        /*
         * The final insn in this block has a source or result
         * register, and the moves we may need to place and
         * schedule may interfere. We need to insert this
         * instruction at the beginning of the primary successor
         * block instead. We know this is safe, because when we
         * edge-split earlier, we ensured that each successor has
         * only us as a predecessor.
         */

        for (int i = successors.nextSetBit(0)
                ; i >= 0
                ; i = successors.nextSetBit(i + 1)) {

            SsaBasicBlock succ;

            succ = parent.getBlocks().get(i);
            succ.addMoveToBeginning(result, source);
        }
    } else {
        /*
         * We can safely add a move to the end of the block just
         * before the last instruction, because the final insn does
         * not assign to anything.
         */
        RegisterSpecList sources = RegisterSpecList.make(source);
        NormalSsaInsn toAdd = new NormalSsaInsn(
                new PlainInsn(Rops.opMove(result.getType()),
                        SourcePosition.NO_INFO, result, sources), this);

        insns.add(insns.size() - 1, toAdd);

        movesFromPhisAtEnd++;
    }
}
 

/**
 * Inserts a move instruction for a specified SSA register before a
 * specified instruction, creating a new SSA register and adjusting the
 * interference graph in the process. The insn currently must be the
 * last insn in a block.
 *
 * @param insn {@code non-null;} insn to insert move before, must
 * be last insn in block
 * @param reg {@code non-null;} SSA register to duplicate
 * @return {@code non-null;} spec of new SSA register created by move
 */
protected final RegisterSpec insertMoveBefore(SsaInsn insn,
        RegisterSpec reg) {
    SsaBasicBlock block = insn.getBlock();
    ArrayList<SsaInsn> insns = block.getInsns();
    int insnIndex = insns.indexOf(insn);

    if (insnIndex < 0) {
        throw new IllegalArgumentException (
                "specified insn is not in this block");
    }

    if (insnIndex != insns.size() - 1) {
        /*
         * Presently, the interference updater only works when
         * adding before the last insn, and the last insn must have no
         * result
         */
        throw new IllegalArgumentException(
                "Adding move here not supported:" + insn.toHuman());
    }

    /*
     * Get new register and make new move instruction.
     */

    // The new result must not have an associated local variable.
    RegisterSpec newRegSpec = RegisterSpec.make(ssaMeth.makeNewSsaReg(),
            reg.getTypeBearer());

    SsaInsn toAdd = SsaInsn.makeFromRop(
            new PlainInsn(Rops.opMove(newRegSpec.getType()),
                    SourcePosition.NO_INFO, newRegSpec,
                    RegisterSpecList.make(reg)), block);

    insns.add(insnIndex, toAdd);

    int newReg = newRegSpec.getReg();

    /*
     * Adjust interference graph based on what's live out of the current
     * block and what's used by the final instruction.
     */

    IntSet liveOut = block.getLiveOutRegs();
    IntIterator liveOutIter = liveOut.iterator();

    while (liveOutIter.hasNext()) {
        interference.add(newReg, liveOutIter.next());
    }

    // Everything that's a source in the last insn interferes.
    RegisterSpecList sources = insn.getSources();
    int szSources = sources.size();

    for (int i = 0; i < szSources; i++) {
        interference.add(newReg, sources.get(i).getReg());
    }

    ssaMeth.onInsnsChanged();

    return newRegSpec;
}
 

/**
 * Adds a move instruction to the end of this basic block, just
 * before the last instruction. If the result of the final instruction
 * is the source in question, then the move is placed at the beginning of
 * the primary successor block. This is for unversioned registers.
 *
 * @param result move destination
 * @param source move source
 */
public void addMoveToEnd(RegisterSpec result, RegisterSpec source) {

    if (result.getReg() == source.getReg()) {
        // Sometimes we end up with no-op moves. Ignore them here.
        return;
    }

    /*
     * The last Insn has to be a normal SSA insn: a phi can't branch
     * or return or cause an exception, etc.
     */
    NormalSsaInsn lastInsn;
    lastInsn = (NormalSsaInsn)insns.get(insns.size()-1);

    if (lastInsn.getResult() != null || lastInsn.getSources().size() > 0) {
        /*
         * The final insn in this block has a source or result
         * register, and the moves we may need to place and
         * schedule may interfere. We need to insert this
         * instruction at the beginning of the primary successor
         * block instead. We know this is safe, because when we
         * edge-split earlier, we ensured that each successor has
         * only us as a predecessor.
         */

        for (int i = successors.nextSetBit(0)
                ; i >= 0
                ; i = successors.nextSetBit(i + 1)) {

            SsaBasicBlock succ;

            succ = parent.getBlocks().get(i);
            succ.addMoveToBeginning(result, source);
        }
    } else {
        /*
         * We can safely add a move to the end of the block just
         * before the last instruction, because the final insn does
         * not assign to anything.
         */
        RegisterSpecList sources = RegisterSpecList.make(source);
        NormalSsaInsn toAdd = new NormalSsaInsn(
                new PlainInsn(Rops.opMove(result.getType()),
                        SourcePosition.NO_INFO, result, sources), this);

        insns.add(insns.size() - 1, toAdd);

        movesFromPhisAtEnd++;
    }
}
 

/**
 * Simulates a statement and set the result lattice value.
 * @param insn instruction to simulate
 */
private void simulateStmt(SsaInsn insn) {
    Insn ropInsn = insn.getOriginalRopInsn();
    if (ropInsn.getOpcode().getBranchingness() != Rop.BRANCH_NONE
            || ropInsn.getOpcode().isCallLike()) {
        simulateBranch(insn);
    }

    int opcode = insn.getOpcode().getOpcode();
    RegisterSpec result = insn.getResult();

    if (result == null) {
        // Find move-result-pseudo result for int div and int rem
        if (opcode == RegOps.DIV || opcode == RegOps.REM) {
            SsaBasicBlock succ = insn.getBlock().getPrimarySuccessor();
            result = succ.getInsns().get(0).getResult();
        } else {
            return;
        }
    }

    int resultReg = result.getReg();
    int resultValue = VARYING;
    Constant resultConstant = null;

    switch (opcode) {
        case RegOps.CONST: {
            CstInsn cstInsn = (CstInsn)ropInsn;
            resultValue = CONSTANT;
            resultConstant = cstInsn.getConstant();
            break;
        }
        case RegOps.MOVE: {
            if (insn.getSources().size() == 1) {
                int sourceReg = insn.getSources().get(0).getReg();
                resultValue = latticeValues[sourceReg];
                resultConstant = latticeConstants[sourceReg];
            }
            break;
        }
        case RegOps.ADD:
        case RegOps.SUB:
        case RegOps.MUL:
        case RegOps.DIV:
        case RegOps.AND:
        case RegOps.OR:
        case RegOps.XOR:
        case RegOps.SHL:
        case RegOps.SHR:
        case RegOps.USHR:
        case RegOps.REM: {
            resultConstant = simulateMath(insn, result.getBasicType());
            if (resultConstant != null) {
                resultValue = CONSTANT;
            }
            break;
        }
        case RegOps.MOVE_RESULT_PSEUDO: {
            if (latticeValues[resultReg] == CONSTANT) {
                resultValue = latticeValues[resultReg];
                resultConstant = latticeConstants[resultReg];
            }
            break;
        }
        // TODO: Handle non-int arithmetic.
        // TODO: Eliminate check casts that we can prove the type of.
        default: {}
    }
    if (setLatticeValueTo(resultReg, resultValue, resultConstant)) {
        addUsersToWorklist(resultReg, resultValue);
    }
}
 

/**
 * Inserts a move instruction for a specified SSA register before a
 * specified instruction, creating a new SSA register and adjusting the
 * interference graph in the process. The insn currently must be the
 * last insn in a block.
 *
 * @param insn {@code non-null;} insn to insert move before, must
 * be last insn in block
 * @param reg {@code non-null;} SSA register to duplicate
 * @return {@code non-null;} spec of new SSA register created by move
 */
protected final RegisterSpec insertMoveBefore(SsaInsn insn,
        RegisterSpec reg) {
    SsaBasicBlock block = insn.getBlock();
    ArrayList<SsaInsn> insns = block.getInsns();
    int insnIndex = insns.indexOf(insn);

    if (insnIndex < 0) {
        throw new IllegalArgumentException (
                "specified insn is not in this block");
    }

    if (insnIndex != insns.size() - 1) {
        /*
         * Presently, the interference updater only works when
         * adding before the last insn, and the last insn must have no
         * result
         */
        throw new IllegalArgumentException(
                "Adding move here not supported:" + insn.toHuman());
    }

    /*
     * Get new register and make new move instruction.
     */

    // The new result must not have an associated local variable.
    RegisterSpec newRegSpec = RegisterSpec.make(ssaMeth.makeNewSsaReg(),
            reg.getTypeBearer());

    SsaInsn toAdd = SsaInsn.makeFromRop(
            new PlainInsn(Rops.opMove(newRegSpec.getType()),
                    SourcePosition.NO_INFO, newRegSpec,
                    RegisterSpecList.make(reg)), block);

    insns.add(insnIndex, toAdd);

    int newReg = newRegSpec.getReg();

    /*
     * Adjust interference graph based on what's live out of the current
     * block and what's used by the final instruction.
     */

    IntSet liveOut = block.getLiveOutRegs();
    IntIterator liveOutIter = liveOut.iterator();

    while (liveOutIter.hasNext()) {
        interference.add(newReg, liveOutIter.next());
    }

    // Everything that's a source in the last insn interferes.
    RegisterSpecList sources = insn.getSources();
    int szSources = sources.size();

    for (int i = 0; i < szSources; i++) {
        interference.add(newReg, sources.get(i).getReg());
    }

    ssaMeth.onInsnsChanged();

    return newRegSpec;
}
 

/**
 * Simulates a statement and set the result lattice value.
 * @param insn instruction to simulate
 */
private void simulateStmt(SsaInsn insn) {
    Insn ropInsn = insn.getOriginalRopInsn();
    if (ropInsn.getOpcode().getBranchingness() != Rop.BRANCH_NONE
            || ropInsn.getOpcode().isCallLike()) {
        simulateBranch(insn);
    }

    int opcode = insn.getOpcode().getOpcode();
    RegisterSpec result = insn.getResult();

    if (result == null) {
        // Find move-result-pseudo result for int div and int rem
        if (opcode == RegOps.DIV || opcode == RegOps.REM) {
            SsaBasicBlock succ = insn.getBlock().getPrimarySuccessor();
            result = succ.getInsns().get(0).getResult();
        } else {
            return;
        }
    }

    int resultReg = result.getReg();
    int resultValue = VARYING;
    Constant resultConstant = null;

    switch (opcode) {
        case RegOps.CONST: {
            CstInsn cstInsn = (CstInsn)ropInsn;
            resultValue = CONSTANT;
            resultConstant = cstInsn.getConstant();
            break;
        }
        case RegOps.MOVE: {
            if (insn.getSources().size() == 1) {
                int sourceReg = insn.getSources().get(0).getReg();
                resultValue = latticeValues[sourceReg];
                resultConstant = latticeConstants[sourceReg];
            }
            break;
        }
        case RegOps.ADD:
        case RegOps.SUB:
        case RegOps.MUL:
        case RegOps.DIV:
        case RegOps.AND:
        case RegOps.OR:
        case RegOps.XOR:
        case RegOps.SHL:
        case RegOps.SHR:
        case RegOps.USHR:
        case RegOps.REM: {
            resultConstant = simulateMath(insn, result.getBasicType());
            if (resultConstant != null) {
                resultValue = CONSTANT;
            }
            break;
        }
        case RegOps.MOVE_RESULT_PSEUDO: {
            if (latticeValues[resultReg] == CONSTANT) {
                resultValue = latticeValues[resultReg];
                resultConstant = latticeConstants[resultReg];
            }
            break;
        }
        // TODO: Handle non-int arithmetic.
        // TODO: Eliminate check casts that we can prove the type of.
        default: {}
    }
    if (setLatticeValueTo(resultReg, resultValue, resultConstant)) {
        addUsersToWorklist(resultReg, resultValue);
    }
}
 

/**
 * Checks to see if the register is used in a bitset, taking
 * into account its category/width.
 *
 * @param regsUsed set, indexed by register number
 * @param rs register to mark as used
 * @return true if register is fully or partially (for the case of wide
 * registers) used.
 */
private static boolean checkRegUsed (BitSet regsUsed, RegisterSpec rs) {
    int reg = rs.getReg();
    int category = rs.getCategory();

    return regsUsed.get(reg)
            || (category == 2 ? regsUsed.get(reg + 1) : false);
}
 

/**
 * Checks to see if the register is used in a bitset, taking
 * into account its category/width.
 *
 * @param regsUsed set, indexed by register number
 * @param rs register to mark as used
 * @return true if register is fully or partially (for the case of wide
 * registers) used.
 */
private static boolean checkRegUsed (BitSet regsUsed, RegisterSpec rs) {
    int reg = rs.getReg();
    int category = rs.getCategory();

    return regsUsed.get(reg)
            || (category == 2 ? regsUsed.get(reg + 1) : false);
}
 

/**
 * Constructs a new phi insn with no operands.
 *
 * @param resultReg the result reg for this phi insn
 * @param block block containing this insn.
 */
public PhiInsn(RegisterSpec resultReg, SsaBasicBlock block) {
    super(resultReg, block);
    ropResultReg = resultReg.getReg();
}