Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Binius counts #353

Open
wants to merge 3 commits into
base: main
Choose a base branch
from
Open

Binius counts #353

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
ea9f4f6
almost working with const fn; BinaryField::mul has no constant analog
sragss May 9, 2024
d2671ee
switch to OnceCell for statics
sragss May 9, 2024
1241739
refactor lazy computations to seperate file
sragss May 9, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
refactor lazy computations to seperate file
  • Loading branch information
@sragss
sragss committed May 9, 2024
commit 1241739007964a4e2c2ba71fc07e76082a0ca925
125 changes: 25 additions & 100 deletions jolt-core/src/field/binius.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,49 +2,37 @@ use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
use binius_field::{BinaryField, BinaryField128b, BinaryField128bPolyval};
use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, Sub, SubAssign};

use super::JoltField;

use once_cell::sync::Lazy;

static PRECOMPUTED_LOW_128B: Lazy<[BinaryField128b; TABLE_SIZE]> = Lazy::new(|| {
compute_powers::<BinaryField128b, TABLE_SIZE>(BinaryField128b::MULTIPLICATIVE_GENERATOR)
});
static PRECOMPUTED_HIGH_128B: Lazy<[BinaryField128b; TABLE_SIZE]> = Lazy::new(|| {
compute_powers_starting_from::<BinaryField128b, TABLE_SIZE>(
BinaryField128b::MULTIPLICATIVE_GENERATOR,
16,
)
});
use super::precomputed;
use super::{
precomputed::{
PRECOMPUTED_HIGH_128B, PRECOMPUTED_HIGH_128B_POLYVAL, PRECOMPUTED_LOW_128B,
PRECOMPUTED_LOW_128B_POLYVAL,
},
JoltField,
};

impl BiniusConstructable for BinaryField128b {
fn new(n: u64) -> Self {
Self::new(n as u128)
}

fn precomputed_generator_multiples(
) -> (&'static [Self; TABLE_SIZE], &'static [Self; TABLE_SIZE]) {
fn precomputed_generator_multiples() -> (
&'static [Self; precomputed::TABLE_SIZE],
&'static [Self; precomputed::TABLE_SIZE],
) {
(&PRECOMPUTED_LOW_128B, &PRECOMPUTED_HIGH_128B)
}
}

static PRECOMPUTED_LOW_128B_POLYVAL: Lazy<[BinaryField128bPolyval; TABLE_SIZE]> = Lazy::new(|| {
compute_powers::<BinaryField128bPolyval, TABLE_SIZE>(
BinaryField128bPolyval::MULTIPLICATIVE_GENERATOR,
)
});
static PRECOMPUTED_HIGH_128B_POLYVAL: Lazy<[BinaryField128bPolyval; TABLE_SIZE]> =
Lazy::new(|| {
compute_powers_starting_from::<BinaryField128bPolyval, TABLE_SIZE>(
BinaryField128bPolyval::MULTIPLICATIVE_GENERATOR,
16,
)
});
impl BiniusConstructable for BinaryField128bPolyval {
fn new(n: u64) -> Self {
Self::new(n as u128)
}

fn precomputed_generator_multiples(
) -> (&'static [Self; TABLE_SIZE], &'static [Self; TABLE_SIZE]) {
fn precomputed_generator_multiples() -> (
&'static [Self; precomputed::TABLE_SIZE],
&'static [Self; precomputed::TABLE_SIZE],
) {
(
&PRECOMPUTED_LOW_128B_POLYVAL,
&PRECOMPUTED_HIGH_128B_POLYVAL,
Expand All @@ -58,9 +46,6 @@ impl BiniusSpecific for BinaryField128bPolyval {}
/// Trait for BiniusField functionality specific to each impl.
pub trait BiniusSpecific: binius_field::TowerField + BiniusConstructable + bytemuck::Pod {}

const LOG_TABLE_SIZE: usize = 16;
const TABLE_SIZE: usize = 1 << LOG_TABLE_SIZE;

pub trait BiniusConstructable: BinaryField {
fn new(n: u64) -> Self;

Expand All @@ -76,23 +61,23 @@ pub trait BiniusConstructable: BinaryField {
/// This is achieved with two lookups (one from each table) and a single multiplication.
///
/// `precomputed_generator_multiples() -> (&low_table, &high_table)`
fn precomputed_generator_multiples(
) -> (&'static [Self; TABLE_SIZE], &'static [Self; TABLE_SIZE]);
fn precomputed_generator_multiples() -> (
&'static [Self; precomputed::TABLE_SIZE],
&'static [Self; precomputed::TABLE_SIZE],
);

fn from_count_index(n: u64) -> Self {
const MAX_COUNTS: usize = 1 << (2 * LOG_TABLE_SIZE);
const MAX_COUNTS: usize = 1 << (2 * precomputed::LOG_TABLE_SIZE);
let n = (n) as usize;
assert!(n <= MAX_COUNTS);
assert!(n != 0);

let high_index = (n >> LOG_TABLE_SIZE) as usize;
let low_index = (n & ((1 << LOG_TABLE_SIZE) - 1)) as usize;
let high_index = (n >> precomputed::LOG_TABLE_SIZE) as usize;
let low_index = (n & ((1 << precomputed::LOG_TABLE_SIZE) - 1)) as usize;
let (precomputed_low, precomputed_high) = Self::precomputed_generator_multiples();
// TODO(sragss): mul_0_optimized
if n < TABLE_SIZE {
if n < precomputed::TABLE_SIZE {
precomputed_low[n]
} else {
println!("low[{low_index}] * high[{high_index}]");
precomputed_low[low_index] * precomputed_high[high_index]
}
}
Expand Down Expand Up @@ -260,71 +245,11 @@ impl<F: BiniusSpecific> ark_serialize::Valid for BiniusField<F> {
}
}

/// Computes `N` sequential powers of base^{[0, ... N]}
const fn compute_powers<F: binius_field::BinaryField, const N: usize>(base: F) -> [F; N] {
let mut powers = [F::ZERO; N];
powers[0] = F::ONE;
powers[1] = base;
let mut i = 2;
while i < N {
powers[i] = powers[i - 1] * base;
i += 1;
}
powers
}

/// Computes `N` sequential powers of base^{2^starting_power}: {base^{2^starting_power}}^{[1, ... N]}
const fn compute_powers_starting_from<F: binius_field::BinaryField, const N: usize>(
base: F,
starting_power: usize,
) -> [F; N] {
let mut starting = base;
let mut count = 0;
// // Repeated squaring
while count < starting_power {
starting = starting.mul(starting);
count += 1;
}
compute_powers::<F, N>(starting)
}

#[cfg(test)]
mod tests {
use super::*;
use binius_field::Field;

#[test]
fn test_compute_powers() {
let base = BinaryField128b::MULTIPLICATIVE_GENERATOR;
let powers = compute_powers::<BinaryField128b, 5>(base);
let expected_powers = [
BinaryField128b::ONE,
base,
base * base,
base * base * base,
base * base * base * base,
];
assert_eq!(powers, expected_powers);
}

#[test]
fn test_compute_powers_starting_from() {
let base = BinaryField128b::MULTIPLICATIVE_GENERATOR;
let powers = compute_powers_starting_from::<BinaryField128b, 5>(base, 2);
let expected_starting_base = base * base * base * base;
let expected_powers = [
BinaryField128b::ONE,
expected_starting_base,
expected_starting_base * expected_starting_base,
expected_starting_base * expected_starting_base * expected_starting_base,
expected_starting_base
* expected_starting_base
* expected_starting_base
* expected_starting_base,
];
assert_eq!(powers, expected_powers);
}

#[test]
fn test_from_count_index() {
let actual = BiniusField::<BinaryField128b>::from_count_index(1);
Expand Down
1 change: 1 addition & 0 deletions jolt-core/src/field/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -42,3 +42,4 @@ pub trait JoltField:

pub mod ark;
pub mod binius;
mod precomputed;
97 changes: 97 additions & 0 deletions jolt-core/src/field/precomputed.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,97 @@
use binius_field::{BinaryField, BinaryField128b, BinaryField128bPolyval};
use once_cell::sync::Lazy;

pub const LOG_TABLE_SIZE: usize = 16;
pub const TABLE_SIZE: usize = 1 << LOG_TABLE_SIZE;

// BinaryField128b
pub static PRECOMPUTED_LOW_128B: Lazy<[BinaryField128b; TABLE_SIZE]> = Lazy::new(|| {
compute_powers::<BinaryField128b, TABLE_SIZE>(BinaryField128b::MULTIPLICATIVE_GENERATOR)
});
pub static PRECOMPUTED_HIGH_128B: Lazy<[BinaryField128b; TABLE_SIZE]> = Lazy::new(|| {
compute_powers_starting_from::<BinaryField128b, TABLE_SIZE>(
BinaryField128b::MULTIPLICATIVE_GENERATOR,
16,
)
});

// BinaryField128bPolyval
pub static PRECOMPUTED_LOW_128B_POLYVAL: Lazy<[BinaryField128bPolyval; TABLE_SIZE]> =
Lazy::new(|| {
compute_powers::<BinaryField128bPolyval, TABLE_SIZE>(
BinaryField128bPolyval::MULTIPLICATIVE_GENERATOR,
)
});
pub static PRECOMPUTED_HIGH_128B_POLYVAL: Lazy<[BinaryField128bPolyval; TABLE_SIZE]> =
Lazy::new(|| {
compute_powers_starting_from::<BinaryField128bPolyval, TABLE_SIZE>(
BinaryField128bPolyval::MULTIPLICATIVE_GENERATOR,
16,
)
});

/// Computes `N` sequential powers of base^{[0, ... N]}
const fn compute_powers<F: binius_field::BinaryField, const N: usize>(base: F) -> [F; N] {
let mut powers = [F::ZERO; N];
powers[0] = F::ONE;
powers[1] = base;
let mut i = 2;
while i < N {
powers[i] = powers[i - 1] * base;
i += 1;
}
powers
}

/// Computes `N` sequential powers of base^{2^starting_power}: {base^{2^starting_power}}^{[1, ... N]}
const fn compute_powers_starting_from<F: binius_field::BinaryField, const N: usize>(
base: F,
starting_power: usize,
) -> [F; N] {
let mut starting = base;
let mut count = 0;
// // Repeated squaring
while count < starting_power {
starting = starting.mul(starting);
count += 1;
}
compute_powers::<F, N>(starting)
}

#[cfg(test)]
mod tests {
use super::*;
use binius_field::{BinaryField, Field};

#[test]
fn test_compute_powers() {
let base = BinaryField128b::MULTIPLICATIVE_GENERATOR;
let powers = compute_powers::<BinaryField128b, 5>(base);
let expected_powers = [
BinaryField128b::ONE,
base,
base * base,
base * base * base,
base * base * base * base,
];
assert_eq!(powers, expected_powers);
}

#[test]
fn test_compute_powers_starting_from() {
let base = BinaryField128b::MULTIPLICATIVE_GENERATOR;
let powers = compute_powers_starting_from::<BinaryField128b, 5>(base, 2);
let expected_starting_base = base * base * base * base;
let expected_powers = [
BinaryField128b::ONE,
expected_starting_base,
expected_starting_base * expected_starting_base,
expected_starting_base * expected_starting_base * expected_starting_base,
expected_starting_base
* expected_starting_base
* expected_starting_base
* expected_starting_base,
];
assert_eq!(powers, expected_powers);
}
}