#![allow(non_snake_case)]
#[curve25519_dalek_derive::unsafe_target_feature_specialize(
"avx2",
conditional("avx512ifma,avx512vl", nightly)
)]
pub mod spec {
use core::cmp::Ordering;
#[for_target_feature("avx2")]
use crate::backend::vector::avx2::{CachedPoint, ExtendedPoint};
#[for_target_feature("avx512ifma")]
use crate::backend::vector::ifma::{CachedPoint, ExtendedPoint};
#[cfg(feature = "precomputed-tables")]
#[for_target_feature("avx2")]
use crate::backend::vector::avx2::constants::BASEPOINT_ODD_LOOKUP_TABLE;
#[cfg(feature = "precomputed-tables")]
#[for_target_feature("avx512ifma")]
use crate::backend::vector::ifma::constants::BASEPOINT_ODD_LOOKUP_TABLE;
use crate::edwards::EdwardsPoint;
use crate::scalar::Scalar;
use crate::traits::Identity;
use crate::window::NafLookupTable5;
pub fn mul(a: &Scalar, A: &EdwardsPoint, b: &Scalar) -> EdwardsPoint {
let a_naf = a.non_adjacent_form(5);
#[cfg(feature = "precomputed-tables")]
let b_naf = b.non_adjacent_form(8);
#[cfg(not(feature = "precomputed-tables"))]
let b_naf = b.non_adjacent_form(5);
let mut i: usize = 255;
for j in (0..256).rev() {
i = j;
if a_naf[i] != 0 || b_naf[i] != 0 {
break;
}
}
let table_A = NafLookupTable5::<CachedPoint>::from(A);
#[cfg(feature = "precomputed-tables")]
let table_B = &BASEPOINT_ODD_LOOKUP_TABLE;
#[cfg(not(feature = "precomputed-tables"))]
let table_B =
&NafLookupTable5::<CachedPoint>::from(&crate::constants::ED25519_BASEPOINT_POINT);
let mut Q = ExtendedPoint::identity();
loop {
Q = Q.double();
match a_naf[i].cmp(&0) {
Ordering::Greater => {
Q = &Q + &table_A.select(a_naf[i] as usize);
}
Ordering::Less => {
Q = &Q - &table_A.select(-a_naf[i] as usize);
}
Ordering::Equal => {}
}
match b_naf[i].cmp(&0) {
Ordering::Greater => {
Q = &Q + &table_B.select(b_naf[i] as usize);
}
Ordering::Less => {
Q = &Q - &table_B.select(-b_naf[i] as usize);
}
Ordering::Equal => {}
}
if i == 0 {
break;
}
i -= 1;
}
Q.into()
}
}