@Override
    public Result visit(
            minijava.syntaxtree.IfStatement n, Context argu) {
        minijava.syntaxtree.Expression mjBoolExpr = n.expression;
        minijava.syntaxtree.Statement mjTrueStmt = n.statement;
        minijava.syntaxtree.Statement mjFalseStmt = n.statement1;

        // get two unique `IF?' labels
        PigletLabel pIF2 = createLabel("IF");
        PigletLabel pIF3 = createLabel("IF");

        // MOVE TEMP ? <BoolExpr>
        Result boolResult = mjBoolExpr.accept(this, argu);
        assert(boolResult.node instanceof piglet.syntaxtree.Exp);
        PigletTemp boolTemp = createTemp();
        argu.attachMoveStmt(boolTemp,
                (piglet.syntaxtree.Exp) boolResult.node);
        // CJUMP TEMP ? IF2
        argu.attachCJumpStmt(
                new piglet.syntaxtree.Exp(
                new piglet.syntaxtree.NodeChoice(
                createTempNode(boolTemp), 4)),
                pIF3);
        // TrueStmt
        mjTrueStmt.accept(this, argu);
        // JUMP IF3
        argu.attachJumpStmt(pIF3);
        // IF2: NOOP
        argu.attachLabeledNoOpStmt(pIF2);
        // FalseStmt
        mjFalseStmt.accept(this, argu);
        // IF3: NOOP
        argu.attachLabeledNoOpStmt(pIF3);

        return null;    // XXX: what to do? this returns sibling nodes!
    }