phantom-zone/src/shortint/mod.rs

mod enc_dec;
mod ops;
mod types;

pub type FheUint8 = enc_dec::FheUint8<Vec<u64>>;
pub type FheBool = Vec<u64>;

use crate::bool::{evaluator::BooleanGates, BoolEvaluator, RuntimeServerKey};

mod frontend {
    use super::ops::{
        arbitrary_bit_adder, arbitrary_bit_division_for_quotient_and_rem, arbitrary_bit_subtractor,
        eight_bit_mul,
    };
    use crate::utils::{Global, WithLocal};

    use super::*;

    mod arithetic {

        use super::*;
        use std::ops::{Add, AddAssign, Div, Mul, Rem, Sub};

        impl AddAssign<&FheUint8> for FheUint8 {
            fn add_assign(&mut self, rhs: &FheUint8) {
                BoolEvaluator::with_local_mut_mut(&mut |e| {
                    let key = RuntimeServerKey::global();
                    arbitrary_bit_adder(e, self.data_mut(), rhs.data(), false, key);
                });
            }
        }

        impl Add<&FheUint8> for &FheUint8 {
            type Output = FheUint8;
            fn add(self, rhs: &FheUint8) -> Self::Output {
                let mut a = self.clone();
                a += rhs;
                a
            }
        }

        impl Sub<&FheUint8> for &FheUint8 {
            type Output = FheUint8;
            fn sub(self, rhs: &FheUint8) -> Self::Output {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let (out, _, _) = arbitrary_bit_subtractor(e, self.data(), rhs.data(), key);
                    FheUint8 { data: out }
                })
            }
        }

        impl Mul<&FheUint8> for &FheUint8 {
            type Output = FheUint8;
            fn mul(self, rhs: &FheUint8) -> Self::Output {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let out = eight_bit_mul(e, self.data(), rhs.data(), key);
                    FheUint8 { data: out }
                })
            }
        }

        impl Div<&FheUint8> for &FheUint8 {
            type Output = FheUint8;
            fn div(self, rhs: &FheUint8) -> Self::Output {
                // TODO(Jay:) Figure out how to set zero error flag
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let (quotient, _) = arbitrary_bit_division_for_quotient_and_rem(
                        e,
                        self.data(),
                        rhs.data(),
                        key,
                    );
                    FheUint8 { data: quotient }
                })
            }
        }

        impl Rem<&FheUint8> for &FheUint8 {
            type Output = FheUint8;
            fn rem(self, rhs: &FheUint8) -> Self::Output {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let (_, remainder) = arbitrary_bit_division_for_quotient_and_rem(
                        e,
                        self.data(),
                        rhs.data(),
                        key,
                    );
                    FheUint8 { data: remainder }
                })
            }
        }

        impl FheUint8 {
            pub fn overflowing_add_assign(&mut self, rhs: &FheUint8) -> FheBool {
                BoolEvaluator::with_local_mut_mut(&mut |e| {
                    let key = RuntimeServerKey::global();
                    let (overflow, _) =
                        arbitrary_bit_adder(e, self.data_mut(), rhs.data(), false, key);
                    overflow
                })
            }

            pub fn overflowing_add(self, rhs: &FheUint8) -> (FheUint8, FheBool) {
                BoolEvaluator::with_local_mut(|e| {
                    let mut lhs = self.clone();
                    let key = RuntimeServerKey::global();
                    let (overflow, _) =
                        arbitrary_bit_adder(e, lhs.data_mut(), rhs.data(), false, key);
                    (lhs, overflow)
                })
            }

            pub fn overflowing_sub(&self, rhs: &FheUint8) -> (FheUint8, FheBool) {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let (out, mut overflow, _) =
                        arbitrary_bit_subtractor(e, self.data(), rhs.data(), key);
                    e.not_inplace(&mut overflow);
                    (FheUint8 { data: out }, overflow)
                })
            }

            pub fn div_rem(&self, rhs: &FheUint8) -> (FheUint8, FheUint8) {
                // TODO(Jay:) Figure out how to set zero error flag
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let (quotient, remainder) = arbitrary_bit_division_for_quotient_and_rem(
                        e,
                        self.data(),
                        rhs.data(),
                        key,
                    );
                    (FheUint8 { data: quotient }, FheUint8 { data: remainder })
                })
            }
        }
    }

    mod booleans {
        use crate::shortint::ops::{
            arbitrary_bit_comparator, arbitrary_bit_equality, arbitrary_signed_bit_comparator,
        };

        use super::*;

        impl FheUint8 {
            /// a == b
            pub fn eq(&self, other: &FheUint8) -> FheBool {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    arbitrary_bit_equality(e, self.data(), other.data(), key)
                })
            }

            /// a != b
            pub fn neq(&self, other: &FheUint8) -> FheBool {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let mut is_equal = arbitrary_bit_equality(e, self.data(), other.data(), key);
                    e.not_inplace(&mut is_equal);
                    is_equal
                })
            }

            /// a < b
            pub fn lt(&self, other: &FheUint8) -> FheBool {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    arbitrary_bit_comparator(e, other.data(), self.data(), key)
                })
            }

            /// a > b
            pub fn gt(&self, other: &FheUint8) -> FheBool {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    arbitrary_bit_comparator(e, self.data(), other.data(), key)
                })
            }

            /// a <= b
            pub fn le(&self, other: &FheUint8) -> FheBool {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let mut a_greater_b =
                        arbitrary_bit_comparator(e, self.data(), other.data(), key);
                    e.not_inplace(&mut a_greater_b);
                    a_greater_b
                })
            }

            /// a >= b
            pub fn ge(&self, other: &FheUint8) -> FheBool {
                BoolEvaluator::with_local_mut(|e| {
                    let key = RuntimeServerKey::global();
                    let mut a_less_b = arbitrary_bit_comparator(e, other.data(), self.data(), key);
                    e.not_inplace(&mut a_less_b);
                    a_less_b
                })
            }
        }
    }
}