Function fft_convolution_basic 

pub unsafe extern "C" fn fft_convolution_basic(
    ii: *mut *mut mp_limb_t,
    jj: *mut *mut mp_limb_t,
    depth: slong,
    limbs: slong,
    trunc: slong,
    t1: *mut *mut mp_limb_t,
    t2: *mut *mut mp_limb_t,
    s1: *mut *mut mp_limb_t,
    tt: *mut *mut mp_limb_t,
)