use crate::{
layouts::{VecZnx, VecZnxToMut, VecZnxToRef, ZnxInfos, ZnxView, ZnxViewMut},
reference::znx::{ZnxRotate, ZnxSwitchRing, ZnxZero},
};
pub fn vec_znx_split_ring_tmp_bytes(n: usize) -> usize {
n * size_of::<i64>()
}
pub fn vec_znx_split_ring<R, A, ZNXARI>(res: &mut [R], res_col: usize, a: &A, a_col: usize, tmp: &mut [i64])
where
R: VecZnxToMut,
A: VecZnxToRef,
ZNXARI: ZnxSwitchRing + ZnxRotate + ZnxZero,
{
let a: VecZnx<&[u8]> = a.to_ref();
let a_size = a.size();
let (_n_in, _n_out) = (a.n(), res[0].to_mut().n());
#[cfg(debug_assertions)]
{
assert_eq!(tmp.len(), a.n());
assert!(_n_out < _n_in, "invalid a: output ring degree should be smaller");
res[1..].iter_mut().for_each(|bi| {
assert_eq!(
bi.to_mut().n(),
_n_out,
"invalid input a: all VecZnx must have the same degree"
)
});
assert!(_n_in.is_multiple_of(_n_out));
assert_eq!(res.len(), _n_in / _n_out);
}
res.iter_mut().enumerate().for_each(|(i, bi)| {
let mut bi: VecZnx<&mut [u8]> = bi.to_mut();
let min_size = bi.size().min(a_size);
if i == 0 {
for j in 0..min_size {
ZNXARI::znx_switch_ring(bi.at_mut(res_col, j), a.at(a_col, j));
}
} else {
for j in 0..min_size {
ZNXARI::znx_rotate(-(i as i64), tmp, a.at(a_col, j));
ZNXARI::znx_switch_ring(bi.at_mut(res_col, j), tmp);
}
}
for j in min_size..bi.size() {
ZNXARI::znx_zero(bi.at_mut(res_col, j));
}
})
}