Add ntt for babybear and goldilocks #144
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| impl From<usize> for Goldilocks { | ||
| #[inline] | ||
| fn from(value: usize) -> Self { | ||
| let modulus = Goldilocks::MODULUS_VALUE as usize; | ||
| if value < modulus { | ||
| Self(value as u64) | ||
| } else { | ||
| Self((value % modulus) as u64) | ||
| } | ||
| } | ||
| } |
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Is here value - modulus is enough for case value >= modulus?
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Yes, it is sufficient. I did not mean to optimize this.
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| use crate::{transformation::prime32::ConcreteTable, Field, NTTField}; | ||
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Use ConcreteTable make this implementation is not correctly when feature concrete-ntt is disabled.
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We do not have a non-concrete version yet. That is why I do not use a feature here, which means we have to always use concrete for these two fields.
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We can disable the default feature to disable concrete-ntt.
| fn try_primitive_root(degree: Self::Degree) -> Result<Self, crate::AlgebraError> { | ||
| let modulus_sub_one = BabyBear::MODULUS_VALUE - 1; | ||
| let quotient = modulus_sub_one / degree; | ||
| if modulus_sub_one != quotient * degree { | ||
| return Err(crate::AlgebraError::NoPrimitiveRoot { | ||
| degree: degree.to_string(), | ||
| modulus: BabyBear::MODULUS_VALUE.to_string(), | ||
| }); | ||
| } | ||
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| let mut rng = thread_rng(); | ||
| let distr = distributions::Uniform::new_inclusive(2, modulus_sub_one); | ||
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| let mut w = Self::zero(); | ||
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| if (0..100).any(|_| { | ||
| w = pow( | ||
| Self::new(rand::Rng::sample(&mut rng, distr)), | ||
| quotient as usize, | ||
| ); | ||
| Self::is_primitive_root(w, degree) | ||
| }) { | ||
| Ok(w) | ||
| } else { | ||
| Err(crate::AlgebraError::NoPrimitiveRoot { | ||
| degree: degree.to_string(), | ||
| modulus: BabyBear::MODULUS_VALUE.to_string(), | ||
| }) | ||
| } | ||
| } |
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This function is not necessary now. We just use unreachable!() in it.
| fn try_minimal_primitive_root(degree: Self::Degree) -> Result<Self, crate::AlgebraError> { | ||
| let mut root = Self::try_primitive_root(degree)?; | ||
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| let generator_sq = (root * root).to_root(); | ||
| let mut current_generator = root; | ||
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| for _ in 0..degree { | ||
| if current_generator < root { | ||
| root = current_generator; | ||
| } | ||
| current_generator.mul_root_assign(generator_sq); | ||
| } | ||
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| Ok(root) | ||
| } |
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This function is not necessary now. We just use unreachable!() in it.
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I think it is used in zk, right?
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No, if zk use it, the wrong result will be returned.
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It's not the right way to get the root for user. Concrete generate root with a different way.
| fn try_primitive_root(degree: Self::Degree) -> Result<Self, crate::AlgebraError> { | ||
| let modulus_sub_one = Goldilocks::MODULUS_VALUE - 1; | ||
| let quotient = modulus_sub_one / degree; | ||
| if modulus_sub_one != quotient * degree { | ||
| return Err(crate::AlgebraError::NoPrimitiveRoot { | ||
| degree: degree.to_string(), | ||
| modulus: Goldilocks::MODULUS_VALUE.to_string(), | ||
| }); | ||
| } | ||
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| let mut rng = thread_rng(); | ||
| let distr = distributions::Uniform::new_inclusive(2, modulus_sub_one); | ||
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| let mut w = Self::zero(); | ||
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| if (0..100).any(|_| { | ||
| w = pow( | ||
| Self::new(rand::Rng::sample(&mut rng, distr)), | ||
| quotient as usize, | ||
| ); | ||
| Self::is_primitive_root(w, degree) | ||
| }) { | ||
| Ok(w) | ||
| } else { | ||
| Err(crate::AlgebraError::NoPrimitiveRoot { | ||
| degree: degree.to_string(), | ||
| modulus: Goldilocks::MODULUS_VALUE.to_string(), | ||
| }) | ||
| } | ||
| } |
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This function is not necessary now. We just use unreachable!() in it.
| fn try_minimal_primitive_root(degree: Self::Degree) -> Result<Self, crate::AlgebraError> { | ||
| let mut root = Self::try_primitive_root(degree)?; | ||
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| let generator_sq = (root * root).to_root(); | ||
| let mut current_generator = root; | ||
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| for _ in 0..degree { | ||
| if current_generator < root { | ||
| root = current_generator; | ||
| } | ||
| current_generator.mul_root_assign(generator_sq); | ||
| } | ||
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| Ok(root) | ||
| } |
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This function is not necessary now. We just use unreachable!() in it.
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| use crate::{transformation::prime64::ConcreteTable, Field, NTTField}; | ||
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We need a way to perform when concrete-ntt is not enable
The impl. of ntt uses concrete-ntt.