Examples with SimpleDfs org.mapleir.stdlib.collections.graph.algorithms.SimpleDfs used on opensource projects

Example 1 with SimpleDfs

use of org.mapleir.stdlib.collections.graph.algorithms.SimpleDfs in project maple-ir by LLVM-but-worse.

the class BoissinotDestructor method traverseDominatorTree.

private SimpleDfs<BasicBlock> traverseDominatorTree() {
    FastBlockGraph dominatorTree = new FastBlockGraph();
    resolver.domc.makeTree(dominatorTree);
    dominatorTree.getEntries().add(dummyHead);
    return new SimpleDfs<>(dominatorTree, dummyHead, SimpleDfs.PRE | SimpleDfs.TOPO);
}

Example 2 with SimpleDfs

use of org.mapleir.stdlib.collections.graph.algorithms.SimpleDfs in project maple-ir by LLVM-but-worse.

the class DeadCodeEliminationPass method process.

public void process(ControlFlowGraph cfg) {
    LocalsPool lp = cfg.getLocals();
    boolean c;
    do {
        c = false;
        SimpleDfs<BasicBlock> dfs = new SimpleDfs<>(cfg, cfg.getEntries().iterator().next(), SimpleDfs.PRE);
        List<BasicBlock> pre = dfs.getPreOrder();
        for (BasicBlock b : new HashSet<>(cfg.vertices())) {
            if (!pre.contains(b)) {
                // System.out.println("proc1: " + b);
                for (FlowEdge<BasicBlock> fe : new HashSet<>(cfg.getEdges(b))) {
                    cfg.exciseEdge(fe);
                }
                // System.out.println("removed: ");
                for (Stmt stmt : b) {
                    // System.out.println(" " + (b.indexOf(stmt)) + ". " + stmt);
                    if (stmt instanceof AbstractCopyStmt) {
                        AbstractCopyStmt copy = (AbstractCopyStmt) stmt;
                        lp.defs.remove(copy.getVariable().getLocal());
                    // System.out.println("  kill1 " + copy.getVariable().getLocal());
                    }
                    for (Expr e : stmt.enumerateOnlyChildren()) {
                        if (e.getOpcode() == Opcode.LOCAL_LOAD) {
                            VarExpr v = (VarExpr) e;
                            lp.uses.get(v.getLocal()).remove(v);
                        // System.out.println("  kill2 " + v.getLocal());
                        }
                    }
                }
                cfg.removeVertex(b);
                deadBlocks++;
                c = true;
            } else {
                // System.out.println("proc2: " + b);
                UnconditionalJumpEdge<BasicBlock> uncond = null;
                for (FlowEdge<BasicBlock> fe : cfg.getEdges(b)) {
                    if (fe.getType() == FlowEdges.UNCOND) {
                        uncond = (UnconditionalJumpEdge<BasicBlock>) fe;
                    }
                }
                if (uncond != null) {
                    BasicBlock dst = uncond.dst();
                    List<BasicBlock> verts = new ArrayList<>(cfg.vertices());
                    if (verts.indexOf(b) + 1 == verts.indexOf(dst)) {
                        ImmediateEdge<BasicBlock> im = new ImmediateEdge<>(b, dst);
                        cfg.exciseEdge(uncond);
                        cfg.addEdge(b, im);
                        Stmt stmt = b.remove(b.size() - 1);
                        if (stmt.getOpcode() != Opcode.UNCOND_JUMP) {
                            throw new IllegalStateException(b + " : " + stmt);
                        }
                        immediateJumps++;
                        c = true;
                    }
                }
                // if(cfg.getMethod().toString().equals("cf.k(IIIIII)V")) {}
                Iterator<Stmt> it = b.iterator();
                while (it.hasNext()) {
                    Stmt stmt = it.next();
                    if (stmt.getOpcode() == Opcode.LOCAL_STORE) {
                        AbstractCopyStmt copy = (AbstractCopyStmt) stmt;
                        if (copy.isSynthetic()) {
                            continue;
                        }
                        Local l = copy.getVariable().getLocal();
                        LocalsPool pool = cfg.getLocals();
                        // System.out.println("copy: "+ copy);
                        if (!ConstraintUtil.isUncopyable(copy.getExpression()) && pool.uses.get(l).size() == 0) {
                            for (Expr e : copy.getExpression().enumerateWithSelf()) {
                                if (e.getOpcode() == Opcode.LOCAL_LOAD) {
                                    VarExpr v = (VarExpr) e;
                                    Local l2 = v.getLocal();
                                    pool.uses.remove(l2);
                                }
                            }
                            pool.uses.remove(l);
                            pool.defs.remove(l);
                            it.remove();
                            deadLocals++;
                            c = true;
                        }
                    } else if (stmt.getOpcode() == Opcode.NOP) {
                        it.remove();
                        c = true;
                    }
                }
            }
        }
    // for now
    } while (c);
}