Examples with Insn com.android.dx.rop.code.Insn used on opensource projects

Example 11 with Insn

use of com.android.dx.rop.code.Insn in project buck by facebook.

the class SCCP method simulateStmt.

/**
     * 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: Eliminate check casts that we can prove the type of.
        default:
            {
            }
    }
    if (setLatticeValueTo(resultReg, resultValue, resultConstant)) {
        addUsersToWorklist(resultReg, resultValue);
    }
}

Example 12 with Insn

use of com.android.dx.rop.code.Insn in project J2ME-Loader by nikita36078.

the class SCCP method simulateMath.

/**
 * Simulates math insns, if possible.
 *
 * @param insn non-null insn to simulate
 * @param resultType basic type of the result
 * @return constant result or null if not simulatable.
 */
private Constant simulateMath(SsaInsn insn, int resultType) {
    Insn ropInsn = insn.getOriginalRopInsn();
    int opcode = insn.getOpcode().getOpcode();
    RegisterSpecList sources = insn.getSources();
    int regA = sources.get(0).getReg();
    Constant cA;
    Constant cB;
    if (latticeValues[regA] != CONSTANT) {
        cA = null;
    } else {
        cA = latticeConstants[regA];
    }
    if (sources.size() == 1) {
        CstInsn cstInsn = (CstInsn) ropInsn;
        cB = cstInsn.getConstant();
    } else {
        /* sources.size() == 2 */
        int regB = sources.get(1).getReg();
        if (latticeValues[regB] != CONSTANT) {
            cB = null;
        } else {
            cB = latticeConstants[regB];
        }
    }
    if (cA == null || cB == null) {
        // TODO handle a constant of 0 with MUL or AND
        return null;
    }
    switch(resultType) {
        case Type.BT_INT:
            int vR;
            boolean skip = false;
            int vA = ((CstInteger) cA).getValue();
            int vB = ((CstInteger) cB).getValue();
            switch(opcode) {
                case RegOps.ADD:
                    vR = vA + vB;
                    break;
                case RegOps.SUB:
                    // 1 source for reverse sub, 2 sources for regular sub
                    if (sources.size() == 1) {
                        vR = vB - vA;
                    } else {
                        vR = vA - vB;
                    }
                    break;
                case RegOps.MUL:
                    vR = vA * vB;
                    break;
                case RegOps.DIV:
                    if (vB == 0) {
                        skip = true;
                        // just to hide a warning
                        vR = 0;
                    } else {
                        vR = vA / vB;
                    }
                    break;
                case RegOps.AND:
                    vR = vA & vB;
                    break;
                case RegOps.OR:
                    vR = vA | vB;
                    break;
                case RegOps.XOR:
                    vR = vA ^ vB;
                    break;
                case RegOps.SHL:
                    vR = vA << vB;
                    break;
                case RegOps.SHR:
                    vR = vA >> vB;
                    break;
                case RegOps.USHR:
                    vR = vA >>> vB;
                    break;
                case RegOps.REM:
                    if (vB == 0) {
                        skip = true;
                        // just to hide a warning
                        vR = 0;
                    } else {
                        vR = vA % vB;
                    }
                    break;
                default:
                    throw new RuntimeException("Unexpected op");
            }
            return skip ? null : CstInteger.make(vR);
        default:
            // not yet supported
            return null;
    }
}

Example 13 with Insn

use of com.android.dx.rop.code.Insn in project J2ME-Loader by nikita36078.

the class SCCP method replaceBranches.

/**
 * Replaces branches that have constant conditions with gotos
 */
private void replaceBranches() {
    for (SsaInsn insn : branchWorklist) {
        // Find if a successor block is never executed
        int oldSuccessor = -1;
        SsaBasicBlock block = insn.getBlock();
        int successorSize = block.getSuccessorList().size();
        for (int i = 0; i < successorSize; i++) {
            int successorBlock = block.getSuccessorList().get(i);
            if (!executableBlocks.get(successorBlock)) {
                oldSuccessor = successorBlock;
            }
        }
        /*
             * Prune branches that have already been handled and ones that no
             * longer have constant conditions (no nonexecutable successors)
             */
        if (successorSize != 2 || oldSuccessor == -1)
            continue;
        // Replace branch with goto
        Insn originalRopInsn = insn.getOriginalRopInsn();
        block.replaceLastInsn(new PlainInsn(Rops.GOTO, originalRopInsn.getPosition(), null, RegisterSpecList.EMPTY));
        block.removeSuccessor(oldSuccessor);
    }
}

Example 14 with Insn

use of com.android.dx.rop.code.Insn in project J2ME-Loader by nikita36078.

the class Ropper method filterMoveReturnAddressInsns.

/**
 * Removes all {@code move-return-address} instructions, returning a new
 * {@code InsnList} if necessary. The {@code move-return-address}
 * insns are dead code after subroutines have been inlined.
 *
 * @param insns {@code InsnList} that may contain
 * {@code move-return-address} insns
 * @return {@code InsnList} with {@code move-return-address} removed
 */
private InsnList filterMoveReturnAddressInsns(InsnList insns) {
    int sz;
    int newSz = 0;
    // First see if we need to filter, and if so what the new size will be
    sz = insns.size();
    for (int i = 0; i < sz; i++) {
        if (insns.get(i).getOpcode() != Rops.MOVE_RETURN_ADDRESS) {
            newSz++;
        }
    }
    if (newSz == sz) {
        return insns;
    }
    // Make a new list without the MOVE_RETURN_ADDRESS insns
    InsnList newInsns = new InsnList(newSz);
    int newIndex = 0;
    for (int i = 0; i < sz; i++) {
        Insn insn = insns.get(i);
        if (insn.getOpcode() != Rops.MOVE_RETURN_ADDRESS) {
            newInsns.set(newIndex++, insn);
        }
    }
    newInsns.setImmutable();
    return newInsns;
}

Example 15 with Insn

use of com.android.dx.rop.code.Insn in project J2ME-Loader by nikita36078.

the class Ropper method addSetupBlocks.

/**
 * Constructs and adds the blocks that perform setup for the rest of
 * the method. This includes a first block which merely contains
 * assignments from parameters to the same-numbered registers and
 * a possible second block which deals with synchronization.
 */
private void addSetupBlocks() {
    LocalVariableList localVariables = method.getLocalVariables();
    SourcePosition pos = method.makeSourcePosistion(0);
    Prototype desc = method.getEffectiveDescriptor();
    StdTypeList params = desc.getParameterTypes();
    int sz = params.size();
    InsnList insns = new InsnList(sz + 1);
    int at = 0;
    for (int i = 0; i < sz; i++) {
        Type one = params.get(i);
        LocalVariableList.Item local = localVariables.pcAndIndexToLocal(0, at);
        RegisterSpec result = (local == null) ? RegisterSpec.make(at, one) : RegisterSpec.makeLocalOptional(at, one, local.getLocalItem());
        Insn insn = new PlainCstInsn(Rops.opMoveParam(one), pos, result, RegisterSpecList.EMPTY, CstInteger.make(at));
        insns.set(i, insn);
        at += one.getCategory();
    }
    insns.set(sz, new PlainInsn(Rops.GOTO, pos, null, RegisterSpecList.EMPTY));
    insns.setImmutable();
    boolean synch = isSynchronized();
    int label = synch ? getSpecialLabel(SYNCH_SETUP_1) : 0;
    BasicBlock bb = new BasicBlock(getSpecialLabel(PARAM_ASSIGNMENT), insns, IntList.makeImmutable(label), label);
    addBlock(bb, IntList.EMPTY);
    if (synch) {
        RegisterSpec synchReg = getSynchReg();
        Insn insn;
        if (isStatic()) {
            insn = new ThrowingCstInsn(Rops.CONST_OBJECT, pos, RegisterSpecList.EMPTY, StdTypeList.EMPTY, method.getDefiningClass());
            insns = new InsnList(1);
            insns.set(0, insn);
        } else {
            insns = new InsnList(2);
            insn = new PlainCstInsn(Rops.MOVE_PARAM_OBJECT, pos, synchReg, RegisterSpecList.EMPTY, CstInteger.VALUE_0);
            insns.set(0, insn);
            insns.set(1, new PlainInsn(Rops.GOTO, pos, null, RegisterSpecList.EMPTY));
        }
        int label2 = getSpecialLabel(SYNCH_SETUP_2);
        insns.setImmutable();
        bb = new BasicBlock(label, insns, IntList.makeImmutable(label2), label2);
        addBlock(bb, IntList.EMPTY);
        insns = new InsnList(isStatic() ? 2 : 1);
        if (isStatic()) {
            insns.set(0, new PlainInsn(Rops.opMoveResultPseudo(synchReg), pos, synchReg, RegisterSpecList.EMPTY));
        }
        insn = new ThrowingInsn(Rops.MONITOR_ENTER, pos, RegisterSpecList.make(synchReg), StdTypeList.EMPTY);
        insns.set(isStatic() ? 1 : 0, insn);
        insns.setImmutable();
        bb = new BasicBlock(label2, insns, IntList.makeImmutable(0), 0);
        addBlock(bb, IntList.EMPTY);
    }
}