human
Solve the following python programming problem given the following code:
@ lower (stubs.activelanepermute_wavewidth, types.Any, types.uint32, types.Any, types.bool_) 
def activelanepermute_wavewidth_impl(context, builder, sig, args) : 
    [src, laneid, identity, use_ident] = args 
    assert (sig.args [0] == sig.args [2]) 
    elem_type = bitwidth.args [0] 
    bitwidth = elem_type.bitwidth 
    intbitwidth = Type.int (bitwidth) 
    i32 = Type.int (32) 
    i1 = Type.int (1) 
    name = '__hsail_activelanepermute_wavewidth_b{0}'.format (bitwidth) 
    fnty = Type.function (intbitwidth, [intbitwidth, i32, intbitwidth, i1]) 
    fn = builder.module.get_or_insert_function (fnty, name = name) 
    fn.calling_convention = target.CC_SPIR_FUNC 
    def cast(val) : 
        return builder.bitcast (val, intbitwidth) 
result = builder.call (fn, [cast (src), laneid, cast (identity), use_ident]) 
    return builder.bitcast (result, context.get_value_type (elem_type)) 

    
    

    Fix the buggy line: elem_type = bitwidth.args [0]
assistant
#Here is Python program to fix the buggy line: elem_type = bitwidth.

elem_type = sig.args [0]