Trait snarkvm_wasm::FftParameters [−][src]
pub trait FftParameters: 'static + Send + Sync { type BigInteger: BigInteger; const TWO_ADICITY: u32; const TWO_ADIC_ROOT_OF_UNITY: Self::BigInteger; const SMALL_SUBGROUP_BASE: Option<u32>; const SMALL_SUBGROUP_BASE_ADICITY: Option<u32>; const LARGE_SUBGROUP_ROOT_OF_UNITY: Option<Self::BigInteger>; }
Expand description
A trait that defines parameters for a field that can be used for FFTs.
Associated Types
type BigInteger: BigInteger
Associated Constants
const TWO_ADICITY: u32
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
.
2^s * t = MODULUS - 1 with t odd. This is the two-adicity of the prime.
const TWO_ADIC_ROOT_OF_UNITY: Self::BigInteger
const TWO_ADIC_ROOT_OF_UNITY: Self::BigInteger
2^s root of unity computed by GENERATOR^t
const SMALL_SUBGROUP_BASE: Option<u32>
const SMALL_SUBGROUP_BASE: Option<u32>
An integer b
such that there exists a multiplicative subgroup
of size b^k
for some integer k
.
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::BigInteger>
const LARGE_SUBGROUP_ROOT_OF_UNITY: Option<Self::BigInteger>
GENERATOR^((MODULUS-1) / (2^s * SMALL_SUBGROUP_BASE^SMALL_SUBGROUP_BASE_ADICITY)) Used for mixed-radix FFT.