Function jerasure_matrix_multiply 

pub unsafe extern "C" fn jerasure_matrix_multiply(
    m1: *mut c_int,
    m2: *mut c_int,
    r1: c_int,
    c1: c_int,
    r2: c_int,
    c2: c_int,
    w: c_int,
) -> *mut c_int