Trait mina_curves::pasta::fields::fft::FftParameters
source · 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;
}
Expand description
A trait that defines parameters for a field that can be used for FFTs.
Required Associated Types§
Required Associated Constants§
sourceconst 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
.
sourceconst TWO_ADIC_ROOT_OF_UNITY: Self::BigInt
const TWO_ADIC_ROOT_OF_UNITY: Self::BigInt
2^s root of unity computed by GENERATOR^t
Provided Associated Constants§
sourceconst SMALL_SUBGROUP_BASE: Option<u32> = None
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
.
sourceconst SMALL_SUBGROUP_BASE_ADICITY: Option<u32> = None
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
.
sourceconst LARGE_SUBGROUP_ROOT_OF_UNITY: Option<Self::BigInt> = None
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.