Examples with VarExpr org.mapleir.ir.code.expr.VarExpr used on opensource projects

Example 11 with VarExpr

use of org.mapleir.ir.code.expr.VarExpr in project maple-ir by LLVM-but-worse.

the class SreedharDestructor method checkCoalesce.

private boolean checkCoalesce(CopyVarStmt copy) {
    // Only coalesce simple copies x=y.
    if (copy.isSynthetic() || copy.getExpression().getOpcode() != LOCAL_LOAD)
        return false;
    Local localX = copy.getVariable().getLocal();
    Local localY = ((VarExpr) copy.getExpression()).getLocal();
    GenericBitSet<Local> pccX = pccs.getNonNull(localX), pccY = pccs.getNonNull(localY);
    // Trivial case: Now that we are in CSSA, we can simply drop copies within the same pcc.
    if (pccX == pccY)
        return true;
    boolean xEmpty = pccX.isEmpty(), yEmpty = pccY.isEmpty();
    // Case 1 - If pcc[x] and pcc[y] are empty the copy can be removed regardless of interference.
    if (xEmpty & yEmpty)
        return true;
    else // interfere with any local in (pcc[x]-x).
    if (xEmpty ^ yEmpty) {
        if (checkPccSingle(yEmpty ? pccX : pccY, yEmpty ? localX : localY, yEmpty ? localY : localX))
            return false;
    } else // interferes with any local in (pcc[x]-x) and not local in pcc[x] interferes with any local in (pcc[y]-y).
    if (checkPccDouble(pccX, localX, pccY, localY))
        return false;
    // No interference, copy can be removed
    return true;
}

Example 12 with VarExpr

use of org.mapleir.ir.code.expr.VarExpr in project maple-ir by LLVM-but-worse.

the class SreedharDestructor method insertEnd.

private Local insertEnd(Local xi, BasicBlock lk, Type type) {
    Local spill = locals.makeLatestVersion(xi);
    CopyVarStmt newCopy = new CopyVarStmt(new VarExpr(spill, type), new VarExpr(xi, type));
    if (lk.isEmpty())
        lk.add(newCopy);
    else if (!lk.get(lk.size() - 1).canChangeFlow())
        lk.add(newCopy);
    else
        lk.add(lk.size() - 1, newCopy);
    return spill;
}

Example 13 with VarExpr

use of org.mapleir.ir.code.expr.VarExpr in project maple-ir by LLVM-but-worse.

the class SreedharDestructor method leaveSSA.

// ============================================================================================================= //
// ================================================== Leave SSA ================================================ //
// ============================================================================================================= //
private void leaveSSA() {
    // Flatten pccs into one variable through remapping
    // System.out.println("remap:");
    Map<Local, Local> remap = new HashMap<>();
    for (Entry<Local, GenericBitSet<Local>> entry : pccs.entrySet()) {
        GenericBitSet<Local> pcc = entry.getValue();
        if (pcc.isEmpty())
            continue;
        Local local = entry.getKey();
        if (remap.containsKey(local))
            continue;
        Local newLocal = locals.makeLatestVersion(local);
        remap.put(local, newLocal);
        // System.out.println("  " + local + " -> " + newLocal);
        for (Local pccLocal : pcc) {
            remap.put(pccLocal, newLocal);
        // System.out.println("  " + pccLocal + " -> " + newLocal);
        }
    }
    for (BasicBlock b : cfg.vertices()) {
        for (Iterator<Stmt> it = b.iterator(); it.hasNext(); ) {
            Stmt stmt = it.next();
            // We can now simply drop all phi statements.
            if (stmt instanceof CopyPhiStmt) {
                it.remove();
                continue;
            }
            // Apply remappings
            if (stmt instanceof CopyVarStmt) {
                VarExpr lhs = ((CopyVarStmt) stmt).getVariable();
                Local copyTarget = lhs.getLocal();
                lhs.setLocal(remap.getOrDefault(copyTarget, copyTarget));
            }
            for (Expr child : stmt.enumerateOnlyChildren()) {
                if (child.getOpcode() == LOCAL_LOAD) {
                    VarExpr var = (VarExpr) child;
                    Local loadSource = var.getLocal();
                    var.setLocal(remap.getOrDefault(loadSource, loadSource));
                }
            }
        }
    }
// System.out.println();
}

Example 14 with VarExpr

use of org.mapleir.ir.code.expr.VarExpr in project maple-ir by LLVM-but-worse.

the class SreedharDestructor method insertStart.

// replace the phi target xi with xi' and place a temp copy xi = xi' after all phi statements.
private Local insertStart(PhiResource res, Type type) {
    BasicBlock li = res.block;
    Local xi = res.local;
    if (li.isEmpty())
        throw new IllegalStateException("Trying to resolve phi target interference in empty block " + li);
    Local spill = locals.makeLatestVersion(xi);
    int i;
    for (i = 0; i < li.size() && li.get(i).getOpcode() == Opcode.PHI_STORE; i++) {
        CopyPhiStmt copyPhi = (CopyPhiStmt) li.get(i);
        VarExpr copyTarget = copyPhi.getVariable();
        if (copyTarget.getLocal() == xi)
            copyTarget.setLocal(spill);
    }
    li.add(i, new CopyVarStmt(new VarExpr(xi, type), new VarExpr(spill, type)));
    return spill;
}

Example 15 with VarExpr

use of org.mapleir.ir.code.expr.VarExpr in project maple-ir by LLVM-but-worse.

the class SreedharDestructor method buildInterference.

private void buildInterference() {
    for (BasicBlock b : cfg.vertices()) {
        // not a copy!
        GenericBitSet<Local> in = liveness.in(b);
        // not a copy!
        GenericBitSet<Local> out = liveness.out(b);
        // in interfere in
        for (Local l : in) interfere.getNonNull(l).addAll(in);
        // out interfere out
        for (Local l : out) interfere.getNonNull(l).addAll(out);
        // backwards traverse for dealing with variables that are defined and used in the same block
        GenericBitSet<Local> intraLive = out.copy();
        ListIterator<Stmt> it = b.listIterator(b.size());
        while (it.hasPrevious()) {
            Stmt stmt = it.previous();
            if (stmt instanceof CopyVarStmt) {
                CopyVarStmt copy = (CopyVarStmt) stmt;
                Local defLocal = copy.getVariable().getLocal();
                intraLive.remove(defLocal);
            }
            for (Expr child : stmt.enumerateOnlyChildren()) {
                if (stmt.getOpcode() == LOCAL_LOAD) {
                    Local usedLocal = ((VarExpr) child).getLocal();
                    if (intraLive.add(usedLocal)) {
                        interfere.getNonNull(usedLocal).addAll(intraLive);
                        for (Local l : intraLive) interfere.get(l).add(usedLocal);
                    }
                }
            }
        }
    }
// System.out.println("Interference:");
// for (Entry<Local, GenericBitSet<Local>> entry : interfere.entrySet())
// System.out.println("  " + entry.getKey() + " : " + entry.getValue());
// System.out.println();
}