Java Rop.BRANCH_NONE属性代码示例

/** {@inheritDoc} */
public void visitFillArrayDataInsn(FillArrayDataInsn insn) {
    SourcePosition pos = insn.getPosition();
    Constant cst = insn.getConstant();
    ArrayList<Constant> values = insn.getInitValues();
    Rop rop = insn.getOpcode();

    if (rop.getBranchingness() != Rop.BRANCH_NONE) {
        throw new RuntimeException("shouldn't happen");
    }
    CodeAddress dataAddress = new CodeAddress(pos);
    ArrayData dataInsn =
        new ArrayData(pos, lastAddress, values, cst);

    TargetInsn fillArrayDataInsn =
        new TargetInsn(Dops.FILL_ARRAY_DATA, pos, getRegs(insn),
                dataAddress);

    addOutput(lastAddress);
    addOutput(fillArrayDataInsn);

    addOutputSuffix(new OddSpacer(pos));
    addOutputSuffix(dataAddress);
    addOutputSuffix(dataInsn);
}
 

/**
 * {@inheritDoc}
 *
 * TODO: Increase the scope of this.
 */
@Override
public boolean hasSideEffect() {
    Rop opcode = getOpcode();

    if (opcode.getBranchingness() != Rop.BRANCH_NONE) {
        return true;
    }

    boolean hasLocalSideEffect
        = Optimizer.getPreserveLocals() && getLocalAssignment() != null;

    switch (opcode.getOpcode()) {
        case RegOps.MOVE_RESULT:
        case RegOps.MOVE:
        case RegOps.CONST:
            return hasLocalSideEffect;
        default:
            return true;
    }
}
 

/**
 * {@inheritDoc}
 *
 * TODO: Increase the scope of this.
 * @param optimizer
 */
@Override
public boolean hasSideEffect(Optimizer optimizer) {
    Rop opcode = getOpcode();

    if (opcode.getBranchingness() != Rop.BRANCH_NONE) {
        return true;
    }

    boolean hasLocalSideEffect
        = optimizer.getPreserveLocals() && getLocalAssignment() != null;

    switch (opcode.getOpcode()) {
        case RegOps.MOVE_RESULT:
        case RegOps.MOVE:
        case RegOps.CONST:
            return hasLocalSideEffect;
        default:
            return true;
    }
}
 

/** {@inheritDoc} */
public void visitPlainCstInsn(PlainCstInsn insn) {
    SourcePosition pos = insn.getPosition();
    Dop opcode = RopToDop.dopFor(insn);
    Rop rop = insn.getOpcode();
    int ropOpcode = rop.getOpcode();
    DalvInsn di;

    if (rop.getBranchingness() != Rop.BRANCH_NONE) {
        throw new RuntimeException("shouldn't happen");
    }

    if (ropOpcode == RegOps.MOVE_PARAM) {
        if (!paramsAreInOrder) {
            /*
             * Parameters are not in order at the top of the reg space.
             * We need to add moves.
             */

            RegisterSpec dest = insn.getResult();
            int param =
                ((CstInteger) insn.getConstant()).getValue();
            RegisterSpec source =
                RegisterSpec.make(regCount - paramSize + param,
                        dest.getType());
            di = new SimpleInsn(opcode, pos,
                                RegisterSpecList.make(dest, source));
            addOutput(di);
        }
    } else {
        // No moves required for the parameters
        RegisterSpecList regs = getRegs(insn);
        di = new CstInsn(opcode, pos, regs, insn.getConstant());
        addOutput(di);
    }
}
 

/**
 * Replaces the last insn in this block. The provided insn must have
 * some branchingness.
 *
 * @param insn {@code non-null;} rop-form insn to add, which must branch.
 */
public void replaceLastInsn(Insn insn) {
    if (insn.getOpcode().getBranchingness() == Rop.BRANCH_NONE) {
        throw new IllegalArgumentException("last insn must branch");
    }

    SsaInsn oldInsn = insns.get(insns.size() - 1);
    SsaInsn newInsn = SsaInsn.makeFromRop(insn, this);

    insns.set(insns.size() - 1, newInsn);

    parent.onInsnRemoved(oldInsn);
    parent.onInsnAdded(newInsn);
}
 

/**
 * Deletes all insns in the set from this method.
 *
 * @param deletedInsns {@code non-null;} insns to delete
 */
public void deleteInsns(Set<SsaInsn> deletedInsns) {
    for (SsaBasicBlock block : getBlocks()) {
        ArrayList<SsaInsn> insns = block.getInsns();

        for (int i = insns.size() - 1; i >= 0; i--) {
            SsaInsn insn = insns.get(i);

            if (deletedInsns.contains(insn)) {
                onInsnRemoved(insn);
                insns.remove(i);
            }
        }

        // Check to see if we need to add a GOTO

        int insnsSz = insns.size();
        SsaInsn lastInsn = (insnsSz == 0) ? null : insns.get(insnsSz - 1);

        if (block != getExitBlock() && (insnsSz == 0
                || lastInsn.getOriginalRopInsn() == null
                || lastInsn.getOriginalRopInsn().getOpcode()
                    .getBranchingness() == Rop.BRANCH_NONE)) {
            // We managed to eat a throwable insn

            Insn gotoInsn = new PlainInsn(Rops.GOTO,
                    SourcePosition.NO_INFO, null, RegisterSpecList.EMPTY);
            insns.add(SsaInsn.makeFromRop(gotoInsn, block));

            // Remove secondary successors from this block
            BitSet succs = block.getSuccessors();
            for (int i = succs.nextSetBit(0); i >= 0;
                     i = succs.nextSetBit(i + 1)) {
                if (i != block.getPrimarySuccessorIndex()) {
                    block.removeSuccessor(i);
                }
            }
        }
    }
}
 

/** {@inheritDoc} */
public void visitPlainInsn(PlainInsn insn) {
    Rop rop = insn.getOpcode();
    if (rop.getOpcode() == RegOps.MARK_LOCAL) {
        /*
         * Ignore these. They're dealt with by
         * the LocalVariableAwareTranslationVisitor
         */
        return;
    }
    if (rop.getOpcode() == RegOps.MOVE_RESULT_PSEUDO) {
        // These get skipped
        return;
    }

    SourcePosition pos = insn.getPosition();
    Dop opcode = RopToDop.dopFor(insn);
    DalvInsn di;

    switch (rop.getBranchingness()) {
        case Rop.BRANCH_NONE:
        case Rop.BRANCH_RETURN:
        case Rop.BRANCH_THROW: {
            di = new SimpleInsn(opcode, pos, getRegs(insn));
            break;
        }
        case Rop.BRANCH_GOTO: {
            /*
             * Code in the main translation loop will emit a
             * goto if necessary (if the branch isn't to the
             * immediately subsequent block).
             */
            return;
        }
        case Rop.BRANCH_IF: {
            int target = block.getSuccessors().get(1);
            di = new TargetInsn(opcode, pos, getRegs(insn),
                                addresses.getStart(target));
            break;
        }
        default: {
            throw new RuntimeException("shouldn't happen");
        }
    }

    addOutput(di);
}
 

/**
 * 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);
    }
}
 

/**
 * 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);
}