Examples with TypedConstant com.android.dx.rop.cst.TypedConstant used on opensource projects

Example 6 with TypedConstant

use of com.android.dx.rop.cst.TypedConstant in project J2ME-Loader by nikita36078.

the class SCCP method replaceConstants.

/**
 * Replaces TypeBearers in source register specs with constant type
 * bearers if possible. These are then referenced in later optimization
 * steps.
 */
private void replaceConstants() {
    for (int reg = 0; reg < regCount; reg++) {
        if (latticeValues[reg] != CONSTANT) {
            continue;
        }
        if (!(latticeConstants[reg] instanceof TypedConstant)) {
            // We can't do much with these
            continue;
        }
        SsaInsn defn = ssaMeth.getDefinitionForRegister(reg);
        TypeBearer typeBearer = defn.getResult().getTypeBearer();
        if (typeBearer.isConstant()) {
            /*
                 * The definition was a constant already.
                 * The uses should be as well.
                 */
            continue;
        }
        // Update the destination RegisterSpec with the constant value
        RegisterSpec dest = defn.getResult();
        RegisterSpec newDest = dest.withType((TypedConstant) latticeConstants[reg]);
        defn.setResult(newDest);
        /*
             * Update the sources RegisterSpec's of all non-move uses.
             * These will be used in later steps.
             */
        for (SsaInsn insn : ssaMeth.getUseListForRegister(reg)) {
            if (insn.isPhiOrMove()) {
                continue;
            }
            NormalSsaInsn nInsn = (NormalSsaInsn) insn;
            RegisterSpecList sources = insn.getSources();
            int index = sources.indexOfRegister(reg);
            RegisterSpec spec = sources.get(index);
            RegisterSpec newSpec = spec.withType((TypedConstant) latticeConstants[reg]);
            nInsn.changeOneSource(index, newSpec);
        }
    }
}

Example 7 with TypedConstant

use of com.android.dx.rop.cst.TypedConstant in project J2ME-Loader by nikita36078.

the class ConstCollector method getConstsSortedByCountUse.

/**
 * Gets all of the collectable constant values used in this method,
 * sorted by most used first. Skips non-collectable consts, such as
 * non-string object constants
 *
 * @return {@code non-null;} list of constants in most-to-least used order
 */
private ArrayList<TypedConstant> getConstsSortedByCountUse() {
    int regSz = ssaMeth.getRegCount();
    final HashMap<TypedConstant, Integer> countUses = new HashMap<TypedConstant, Integer>();
    /*
         * Each collected constant can be used by just one local
         * (used only if COLLECT_ONE_LOCAL is true).
         */
    final HashSet<TypedConstant> usedByLocal = new HashSet<TypedConstant>();
    // Count how many times each const value is used.
    for (int i = 0; i < regSz; i++) {
        SsaInsn insn = ssaMeth.getDefinitionForRegister(i);
        if (insn == null || insn.getOpcode() == null)
            continue;
        RegisterSpec result = insn.getResult();
        TypeBearer typeBearer = result.getTypeBearer();
        if (!typeBearer.isConstant())
            continue;
        TypedConstant cst = (TypedConstant) typeBearer;
        // Find defining instruction for move-result-pseudo instructions
        if (insn.getOpcode().getOpcode() == RegOps.MOVE_RESULT_PSEUDO) {
            int pred = insn.getBlock().getPredecessors().nextSetBit(0);
            ArrayList<SsaInsn> predInsns;
            predInsns = ssaMeth.getBlocks().get(pred).getInsns();
            insn = predInsns.get(predInsns.size() - 1);
        }
        if (insn.canThrow()) {
            /*
                 * Don't move anything other than strings -- the risk
                 * of changing where an exception is thrown is too high.
                 */
            if (!(cst instanceof CstString) || !COLLECT_STRINGS) {
                continue;
            }
            /*
                 * We can't move any throwable const whose throw will be
                 * caught, so don't count them.
                 */
            if (insn.getBlock().getSuccessors().cardinality() > 1) {
                continue;
            }
        }
        /*
             * TODO: Might be nice to try and figure out which local
             * wins most when collected.
             */
        if (ssaMeth.isRegALocal(result)) {
            if (!COLLECT_ONE_LOCAL) {
                continue;
            } else {
                if (usedByLocal.contains(cst)) {
                    // Count one local usage only.
                    continue;
                } else {
                    usedByLocal.add(cst);
                }
            }
        }
        Integer has = countUses.get(cst);
        if (has == null) {
            countUses.put(cst, 1);
        } else {
            countUses.put(cst, has + 1);
        }
    }
    // Collect constants that have been reused.
    ArrayList<TypedConstant> constantList = new ArrayList<TypedConstant>();
    for (Map.Entry<TypedConstant, Integer> entry : countUses.entrySet()) {
        if (entry.getValue() > 1) {
            constantList.add(entry.getKey());
        }
    }
    // Sort by use, with most used at the beginning of the list.
    Collections.sort(constantList, new Comparator<Constant>() {

        public int compare(Constant a, Constant b) {
            int ret;
            ret = countUses.get(b) - countUses.get(a);
            if (ret == 0) {
                /*
                     * Provide sorting determinisim for constants with same
                     * usage count.
                     */
                ret = a.compareTo(b);
            }
            return ret;
        }

        @Override
        public boolean equals(Object obj) {
            return obj == this;
        }
    });
    return constantList;
}

Example 8 with TypedConstant

use of com.android.dx.rop.cst.TypedConstant in project buck by facebook.

the class ConstCollector method run.

/**
     * Applies the optimization.
     */
private void run() {
    int regSz = ssaMeth.getRegCount();
    ArrayList<TypedConstant> constantList = getConstsSortedByCountUse();
    int toCollect = Math.min(constantList.size(), MAX_COLLECTED_CONSTANTS);
    SsaBasicBlock start = ssaMeth.getEntryBlock();
    // Constant to new register containing the constant
    HashMap<TypedConstant, RegisterSpec> newRegs = new HashMap<TypedConstant, RegisterSpec>(toCollect);
    for (int i = 0; i < toCollect; i++) {
        TypedConstant cst = constantList.get(i);
        RegisterSpec result = RegisterSpec.make(ssaMeth.makeNewSsaReg(), cst);
        Rop constRop = Rops.opConst(cst);
        if (constRop.getBranchingness() == Rop.BRANCH_NONE) {
            start.addInsnToHead(new PlainCstInsn(Rops.opConst(cst), SourcePosition.NO_INFO, result, RegisterSpecList.EMPTY, cst));
        } else {
            // We need two new basic blocks along with the new insn
            SsaBasicBlock entryBlock = ssaMeth.getEntryBlock();
            SsaBasicBlock successorBlock = entryBlock.getPrimarySuccessor();
            // Insert a block containing the const insn.
            SsaBasicBlock constBlock = entryBlock.insertNewSuccessor(successorBlock);
            constBlock.replaceLastInsn(new ThrowingCstInsn(constRop, SourcePosition.NO_INFO, RegisterSpecList.EMPTY, StdTypeList.EMPTY, cst));
            // Insert a block containing the move-result-pseudo insn.
            SsaBasicBlock resultBlock = constBlock.insertNewSuccessor(successorBlock);
            PlainInsn insn = new PlainInsn(Rops.opMoveResultPseudo(result.getTypeBearer()), SourcePosition.NO_INFO, result, RegisterSpecList.EMPTY);
            resultBlock.addInsnToHead(insn);
        }
        newRegs.put(cst, result);
    }
    updateConstUses(newRegs, regSz);
}

Example 9 with TypedConstant

use of com.android.dx.rop.cst.TypedConstant in project buck by facebook.

the class EscapeAnalysis method replaceDef.

/**
     * Replaces the instructions that define an array with equivalent registers.
     * For each entry in the array, a register is created, initialized to zero.
     * A mapping between this register and the corresponding array index is
     * added.
     *
     * @param def {@code non-null;} move result instruction for array
     * @param prev {@code non-null;} instruction for instantiating new array
     * @param length size of the new array
     * @param newRegs {@code non-null;} mapping of array indices to new
     * registers to be populated
     */
private void replaceDef(SsaInsn def, SsaInsn prev, int length, ArrayList<RegisterSpec> newRegs) {
    Type resultType = def.getResult().getType();
    // Create new zeroed out registers for each element in the array
    for (int i = 0; i < length; i++) {
        Constant newZero = Zeroes.zeroFor(resultType.getComponentType());
        TypedConstant typedZero = (TypedConstant) newZero;
        RegisterSpec newReg = RegisterSpec.make(ssaMeth.makeNewSsaReg(), typedZero);
        newRegs.add(newReg);
        insertPlainInsnBefore(def, RegisterSpecList.EMPTY, newReg, RegOps.CONST, newZero);
    }
}

Example 10 with TypedConstant

use of com.android.dx.rop.cst.TypedConstant in project buck by facebook.

the class StdAttributeFactory method constantValue.

/**
     * Parses a {@code ConstantValue} attribute.
     */
private Attribute constantValue(DirectClassFile cf, int offset, int length, ParseObserver observer) {
    if (length != 2) {
        return throwBadLength(2);
    }
    ByteArray bytes = cf.getBytes();
    ConstantPool pool = cf.getConstantPool();
    int idx = bytes.getUnsignedShort(offset);
    TypedConstant cst = (TypedConstant) pool.get(idx);
    Attribute result = new AttConstantValue(cst);
    if (observer != null) {
        observer.parsed(bytes, offset, 2, "value: " + cst);
    }
    return result;
}