neural/trident/benches/references/common/poseidon_standard.rs

//! Independent u128 integer reference for the upstream Poseidon2-HL width8.
//! Parameters: Plonky3 0.4.2 revision0835481398d2b481bef0c6d0e8188b484ab9a636.
//! This reference uses dense matrix loops, not generated Trident formulas.
const P: u128 = 18446744069414584321;
fn add(a: u64, b: u64) -> u64 {
    ((a as u128 + b as u128) % P) as u64
}
fn mul(a: u64, b: u64) -> u64 {
    ((a as u128 * b as u128) % P) as u64
}
fn power7(a: u64) -> u64 {
    let mut result = 1;
    for _ in 0..7 {
        result = mul(result, a);
    }
    result
}
const M4: [[u64; 4]; 4] = [[5, 7, 1, 3], [4, 6, 1, 1], [1, 3, 5, 7], [1, 1, 4, 6]];
const EXTERNAL: [u64; 64] = [
    15949291268843349465,
    14644164809401934923,
    18420360874837380316,
    4756469047455716334,
    8685499049481102115,
    3799221349720045367,
    13676397835037157930,
    6566439050423619635,
    17428268347612331188,
    2833135872454503769,
    4767009016213040191,
    2797635963551733652,
    5312339450141126694,
    5356668452102813289,
    1234059326449530173,
    7724302552453704877,
    14868588146468890290,
    12825281145595371185,
    13097885453579304196,
    7905326782341128063,
    14167525334039893569,
    2082169701994688927,
    12190787523818595537,
    12602917751946636,
    14890907856876319003,
    16552240149997473409,
    5634093690795187558,
    4883714163685656967,
    12440776365164557866,
    3923800234666204307,
    9858064884105950259,
    16040043470428402038,
    94277733998400326,
    10891359798487446420,
    18280773820738154043,
    13714589910668449566,
    10639034072771185213,
    14148790895768484219,
    18341268649720100165,
    3096672942770686236,
    12277596046563557393,
    400461754528604020,
    12955488253560265444,
    11773677676764285572,
    4833837465239476573,
    17645852643693996619,
    6605134696140007471,
    588040525114200273,
    11001741536026769411,
    17917086578469406776,
    14893530806420712543,
    727997185253761138,
    3443873847340254325,
    13095911531247069692,
    8330737046680948619,
    6014364575875986011,
    16851679856681761121,
    17817965496543149594,
    12823640325246269760,
    13685256787930775147,
    4682652317564502291,
    4233879762155685988,
    11097258179564187322,
    10804761421745472094,
];
const INTERNAL: [u64; 22] = [
    5226594323142090582,
    1243120476974621208,
    12100812801659301173,
    11228203327983058121,
    13891617888374767564,
    5742893160230537107,
    3763472116988983643,
    2466655769425769160,
    6254574254498162968,
    14183251225809189357,
    11565357354521717084,
    17300657704266685688,
    310485250821938281,
    16853586468012618118,
    1978800426240373849,
    6948188224235462572,
    1486402152218690509,
    5669161690283398991,
    17943970877073781734,
    17926851897715769433,
    13052837496695000666,
    18138113741095562305,
];
const DIAG: [u64; 8] = [
    12216033376705242021,
    2072934925475504800,
    16432743296706583078,
    1287600597097751715,
    10482065724875379356,
    3057917794534811537,
    4460508886913832365,
    4574242228824269566,
];
fn external(state: &mut [u64; 8]) {
    let old = *state;
    let mut blocks = [0; 8];
    for b in 0..2 {
        for r in 0..4 {
            for c in 0..4 {
                blocks[b * 4 + r] = add(blocks[b * 4 + r], mul(M4[r][c], old[b * 4 + c]));
            }
        }
    }
    for i in 0..8 {
        state[i] = add(blocks[i], add(blocks[i % 4], blocks[i % 4 + 4]));
    }
}
pub fn permute(mut state: [u64; 8]) -> [u64; 8] {
    external(&mut state);
    for round in 0..30 {
        if round < 4 || round >= 26 {
            let index = if round < 4 { round } else { round - 22 };
            for i in 0..8 {
                state[i] = power7(add(state[i], EXTERNAL[index * 8 + i]));
            }
            external(&mut state);
        } else {
            state[0] = power7(add(state[0], INTERNAL[round - 4]));
            let sum = state.iter().copied().fold(0, add);
            for i in 0..8 {
                state[i] = add(mul(state[i], DIAG[i]), sum);
            }
        }
    }
    state
}
pub fn hash2(a: u64, b: u64) -> u64 {
    permute([a, b, 0, 0, 2, 0, 0, 0])[0]
}