diff options
Diffstat (limited to 'vendor/crypto-bigint/src/uint/bit_and.rs')
-rw-r--r-- | vendor/crypto-bigint/src/uint/bit_and.rs | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/vendor/crypto-bigint/src/uint/bit_and.rs b/vendor/crypto-bigint/src/uint/bit_and.rs new file mode 100644 index 000000000..cab89a429 --- /dev/null +++ b/vendor/crypto-bigint/src/uint/bit_and.rs @@ -0,0 +1,145 @@ +//! [`UInt`] bitwise and operations. + +use super::UInt; +use crate::{Limb, Wrapping}; +use core::ops::{BitAnd, BitAndAssign}; +use subtle::{Choice, CtOption}; + +impl<const LIMBS: usize> UInt<LIMBS> { + /// Computes bitwise `a & b`. + #[inline(always)] + pub const fn bitand(&self, rhs: &Self) -> Self { + let mut limbs = [Limb::ZERO; LIMBS]; + let mut i = 0; + + while i < LIMBS { + limbs[i] = self.limbs[i].bitand(rhs.limbs[i]); + i += 1; + } + + Self { limbs } + } + + /// Perform wrapping bitwise `AND`. + /// + /// There's no way wrapping could ever happen. + /// This function exists so that all operations are accounted for in the wrapping operations + pub const fn wrapping_and(&self, rhs: &Self) -> Self { + self.bitand(rhs) + } + + /// Perform checked bitwise `AND`, returning a [`CtOption`] which `is_some` always + pub fn checked_and(&self, rhs: &Self) -> CtOption<Self> { + let result = self.bitand(rhs); + CtOption::new(result, Choice::from(1)) + } +} + +impl<const LIMBS: usize> BitAnd for UInt<LIMBS> { + type Output = Self; + + fn bitand(self, rhs: Self) -> UInt<LIMBS> { + self.bitand(&rhs) + } +} + +impl<const LIMBS: usize> BitAnd<&UInt<LIMBS>> for UInt<LIMBS> { + type Output = UInt<LIMBS>; + + fn bitand(self, rhs: &UInt<LIMBS>) -> UInt<LIMBS> { + (&self).bitand(rhs) + } +} + +impl<const LIMBS: usize> BitAnd<UInt<LIMBS>> for &UInt<LIMBS> { + type Output = UInt<LIMBS>; + + fn bitand(self, rhs: UInt<LIMBS>) -> UInt<LIMBS> { + self.bitand(&rhs) + } +} + +impl<const LIMBS: usize> BitAnd<&UInt<LIMBS>> for &UInt<LIMBS> { + type Output = UInt<LIMBS>; + + fn bitand(self, rhs: &UInt<LIMBS>) -> UInt<LIMBS> { + self.bitand(rhs) + } +} + +impl<const LIMBS: usize> BitAndAssign for UInt<LIMBS> { + #[allow(clippy::assign_op_pattern)] + fn bitand_assign(&mut self, other: Self) { + *self = *self & other; + } +} + +impl<const LIMBS: usize> BitAndAssign<&UInt<LIMBS>> for UInt<LIMBS> { + #[allow(clippy::assign_op_pattern)] + fn bitand_assign(&mut self, other: &Self) { + *self = *self & other; + } +} + +impl<const LIMBS: usize> BitAnd for Wrapping<UInt<LIMBS>> { + type Output = Self; + + fn bitand(self, rhs: Self) -> Wrapping<UInt<LIMBS>> { + Wrapping(self.0.bitand(&rhs.0)) + } +} + +impl<const LIMBS: usize> BitAnd<&Wrapping<UInt<LIMBS>>> for Wrapping<UInt<LIMBS>> { + type Output = Wrapping<UInt<LIMBS>>; + + fn bitand(self, rhs: &Wrapping<UInt<LIMBS>>) -> Wrapping<UInt<LIMBS>> { + Wrapping(self.0.bitand(&rhs.0)) + } +} + +impl<const LIMBS: usize> BitAnd<Wrapping<UInt<LIMBS>>> for &Wrapping<UInt<LIMBS>> { + type Output = Wrapping<UInt<LIMBS>>; + + fn bitand(self, rhs: Wrapping<UInt<LIMBS>>) -> Wrapping<UInt<LIMBS>> { + Wrapping(self.0.bitand(&rhs.0)) + } +} + +impl<const LIMBS: usize> BitAnd<&Wrapping<UInt<LIMBS>>> for &Wrapping<UInt<LIMBS>> { + type Output = Wrapping<UInt<LIMBS>>; + + fn bitand(self, rhs: &Wrapping<UInt<LIMBS>>) -> Wrapping<UInt<LIMBS>> { + Wrapping(self.0.bitand(&rhs.0)) + } +} + +impl<const LIMBS: usize> BitAndAssign for Wrapping<UInt<LIMBS>> { + #[allow(clippy::assign_op_pattern)] + fn bitand_assign(&mut self, other: Self) { + *self = *self & other; + } +} + +impl<const LIMBS: usize> BitAndAssign<&Wrapping<UInt<LIMBS>>> for Wrapping<UInt<LIMBS>> { + #[allow(clippy::assign_op_pattern)] + fn bitand_assign(&mut self, other: &Self) { + *self = *self & other; + } +} + +#[cfg(test)] +mod tests { + use crate::U128; + + #[test] + fn checked_and_ok() { + let result = U128::ZERO.checked_and(&U128::ONE); + assert_eq!(result.unwrap(), U128::ZERO); + } + + #[test] + fn overlapping_and_ok() { + let result = U128::MAX.wrapping_and(&U128::ONE); + assert_eq!(result, U128::ONE); + } +} |