def is_scalar_zero_or_nan(builder, value):
    """
    Return a predicate representing whether *value* is equal to either zero
    or NaN.
    """
    return _scalar_pred_against_zero(
        builder, value, functools.partial(builder.fcmp_unordered, '=='), '==')

    Return a predicate representing whether *value* is equal to either zero
    or NaN.
    
numba/core/cgutils.py