Function float_subtract 

pub unsafe fn float_subtract(
    _in_buff1: *const u8,
    _in_buff1_len: usize,
    _in_buff2: *const u8,
    _in_buff2_len: usize,
    _out_buff: *mut u8,
    _out_buff_len: usize,
    _rounding_mode: i32,
) -> i32