Trait FftParameters

pub trait FftParameters:
    'static
    + Send
    + Sync
    + Sized {
    type BigInt: BigInteger;

    const TWO_ADICITY: u32;
    const TWO_ADIC_ROOT_OF_UNITY: Self::BigInt;
    const SMALL_SUBGROUP_BASE: Option<u32> = None;
    const SMALL_SUBGROUP_BASE_ADICITY: Option<u32> = None;
    const LARGE_SUBGROUP_ROOT_OF_UNITY: Option<Self::BigInt> = None;
}

A trait that defines parameters for a field that can be used for FFTs.

Required Associated Constants

const TWO_ADICITY: u32

Let N be the size of the multiplicative group defined by the field. Then TWO_ADICITY is the two-adicity of N, i.e. the integer s such that N = 2^s * t for some odd integer t.

const TWO_ADIC_ROOT_OF_UNITY: Self::BigInt

2^s root of unity computed by GENERATOR^t

Provided Associated Constants

const SMALL_SUBGROUP_BASE: Option<u32> = None

An integer b such that there exists a multiplicative subgroup of size b^k for some integer k.

const SMALL_SUBGROUP_BASE_ADICITY: Option<u32> = None

The integer k such that there exists a multiplicative subgroup of size Self::SMALL_SUBGROUP_BASE^k.

const LARGE_SUBGROUP_ROOT_OF_UNITY: Option<Self::BigInt> = None

GENERATOR^((MODULUS-1) / (2^s * SMALL_SUBGROUP_BASE^SMALL_SUBGROUP_BASE_ADICITY)) Used for mixed-radix FFT.

Required Associated Types

type BigInt: BigInteger

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl FftParameters for FpParameters

const TWO_ADICITY: u32 = 32u32

const TWO_ADIC_ROOT_OF_UNITY: BigInteger

type BigInt = BigInt<4>

impl FftParameters for FqParameters

const TWO_ADICITY: u32 = 32u32

const TWO_ADIC_ROOT_OF_UNITY: BigInteger

type BigInt = BigInt<4>