def test_no_fusion_convoluted(self):
        """
        Conceptually like `test_no_fusion_simple`, but with more expressions
        and non-trivial data flow.
        """
        grid = Grid(shape=(4, 4, 4))
        time = grid.time_dim

        f = TimeFunction(name='f', grid=grid)
        g = Function(name='g', grid=grid)
        h = Function(name='h', grid=grid)

        ctime = ConditionalDimension(name='ctime', parent=time, condition=time > 4)

        eqns = [Eq(f.forward, f + 1),
                Eq(h, f + 1),
                Eq(g, f + 1, implicit_dims=[ctime]),
                Eq(f.forward, f + 1, implicit_dims=[ctime]),
                Eq(f.forward, f + 1),
                Eq(g, f + 1)]

        op = Operator(eqns)

        exprs = FindNodes(Expression).visit(op._func_table['bf0'].root)
        assert len(exprs) == 3
        assert exprs[1].expr.rhs is exprs[0].output
        assert exprs[2].expr.rhs is exprs[0].output

        exprs = FindNodes(Expression).visit(op._func_table['bf1'].root)
        assert len(exprs) == 3

        exprs = FindNodes(Expression).visit(op._func_table['bf2'].root)
        assert len(exprs) == 3
        assert exprs[1].expr.rhs is exprs[0].output
        assert exprs[2].expr.rhs is exprs[0].output