binius_field/arch/portable/byte_sliced/
square.rs

1// Copyright 2024-2025 Irreducible Inc.
2use super::multiply::mul_alpha;
3use crate::{
4	tower_levels::{TowerLevel, TowerLevelWithArithOps},
5	underlier::WithUnderlier,
6	AESTowerField8b, PackedField,
7};
8
9#[inline(always)]
10pub fn square<P: PackedField<Scalar = AESTowerField8b>, Level: TowerLevel>(
11	field_element: &Level::Data<P>,
12	destination: &mut Level::Data<P>,
13) {
14	let base_alpha = P::broadcast(AESTowerField8b::from_underlier(0xd3));
15	square_main::<true, P, Level>(field_element, destination, base_alpha);
16}
17
18#[inline(always)]
19pub fn square_main<
20	const WRITING_TO_ZEROS: bool,
21	P: PackedField<Scalar = AESTowerField8b>,
22	Level: TowerLevel,
23>(
24	field_element: &Level::Data<P>,
25	destination: &mut Level::Data<P>,
26	base_alpha: P,
27) {
28	if Level::WIDTH == 1 {
29		if WRITING_TO_ZEROS {
30			destination.as_mut()[0] = field_element[0].square();
31		} else {
32			destination.as_mut()[0] += field_element[0].square();
33		}
34		return;
35	}
36
37	let (a0, a1) = Level::split(field_element);
38
39	let (result0, result1) = Level::split_mut(destination);
40	let mut a1_squared = <<Level as TowerLevel>::Base as TowerLevel>::default();
41
42	square_main::<true, P, Level::Base>(a1, &mut a1_squared, base_alpha);
43
44	mul_alpha::<WRITING_TO_ZEROS, P, Level::Base>(&a1_squared, result1, base_alpha);
45
46	square_main::<WRITING_TO_ZEROS, P, Level::Base>(a0, result0, base_alpha);
47
48	Level::Base::add_into(&a1_squared, result0);
49}
binius_field/arch/portable/byte_sliced/square.rs

binius_field/arch/portable/byte_sliced/
square.rs
