Merging upstream version 1.70.0+dfsg2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 189 insertions, 0 deletions

diff --git a/vendor/crypto-bigint/src/uint/add.rs b/vendor/crypto-bigint/src/uint/add.rs
new file mode 100644
index 000000000..2822e9e67
--- /dev/null
+++ b/vendor/crypto-bigint/src/uint/add.rs
@@ -0,0 +1,189 @@
+//! [`UInt`] addition operations.
+
+use crate::{Checked, CheckedAdd, Limb, UInt, Wrapping, Zero};
+use core::ops::{Add, AddAssign};
+use subtle::CtOption;
+
+impl<const LIMBS: usize> UInt<LIMBS> {
+    /// Computes `a + b + carry`, returning the result along with the new carry.
+    #[inline(always)]
+    pub const fn adc(&self, rhs: &Self, mut carry: Limb) -> (Self, Limb) {
+        let mut limbs = [Limb::ZERO; LIMBS];
+        let mut i = 0;
+
+        while i < LIMBS {
+            let (w, c) = self.limbs[i].adc(rhs.limbs[i], carry);
+            limbs[i] = w;
+            carry = c;
+            i += 1;
+        }
+
+        (Self { limbs }, carry)
+    }
+
+    /// Perform saturating addition, returning `MAX` on overflow.
+    pub const fn saturating_add(&self, rhs: &Self) -> Self {
+        let (res, overflow) = self.adc(rhs, Limb::ZERO);
+
+        if overflow.0 == 0 {
+            res
+        } else {
+            Self::MAX
+        }
+    }
+
+    /// Perform wrapping addition, discarding overflow.
+    pub const fn wrapping_add(&self, rhs: &Self) -> Self {
+        self.adc(rhs, Limb::ZERO).0
+    }
+}
+
+impl<const LIMBS: usize> CheckedAdd<&UInt<LIMBS>> for UInt<LIMBS> {
+    type Output = Self;
+
+    fn checked_add(&self, rhs: &Self) -> CtOption<Self> {
+        let (result, carry) = self.adc(rhs, Limb::ZERO);
+        CtOption::new(result, carry.is_zero())
+    }
+}
+
+impl<const LIMBS: usize> Add for Wrapping<UInt<LIMBS>> {
+    type Output = Self;
+
+    fn add(self, rhs: Self) -> Wrapping<UInt<LIMBS>> {
+        Wrapping(self.0.wrapping_add(&rhs.0))
+    }
+}
+
+impl<const LIMBS: usize> Add<&Wrapping<UInt<LIMBS>>> for Wrapping<UInt<LIMBS>> {
+    type Output = Wrapping<UInt<LIMBS>>;
+
+    fn add(self, rhs: &Wrapping<UInt<LIMBS>>) -> Wrapping<UInt<LIMBS>> {
+        Wrapping(self.0.wrapping_add(&rhs.0))
+    }
+}
+
+impl<const LIMBS: usize> Add<Wrapping<UInt<LIMBS>>> for &Wrapping<UInt<LIMBS>> {
+    type Output = Wrapping<UInt<LIMBS>>;
+
+    fn add(self, rhs: Wrapping<UInt<LIMBS>>) -> Wrapping<UInt<LIMBS>> {
+        Wrapping(self.0.wrapping_add(&rhs.0))
+    }
+}
+
+impl<const LIMBS: usize> Add<&Wrapping<UInt<LIMBS>>> for &Wrapping<UInt<LIMBS>> {
+    type Output = Wrapping<UInt<LIMBS>>;
+
+    fn add(self, rhs: &Wrapping<UInt<LIMBS>>) -> Wrapping<UInt<LIMBS>> {
+        Wrapping(self.0.wrapping_add(&rhs.0))
+    }
+}
+
+impl<const LIMBS: usize> AddAssign for Wrapping<UInt<LIMBS>> {
+    fn add_assign(&mut self, other: Self) {
+        *self = *self + other;
+    }
+}
+
+impl<const LIMBS: usize> AddAssign<&Wrapping<UInt<LIMBS>>> for Wrapping<UInt<LIMBS>> {
+    fn add_assign(&mut self, other: &Self) {
+        *self = *self + other;
+    }
+}
+
+impl<const LIMBS: usize> Add for Checked<UInt<LIMBS>> {
+    type Output = Self;
+
+    fn add(self, rhs: Self) -> Checked<UInt<LIMBS>> {
+        Checked(
+            self.0
+                .and_then(|lhs| rhs.0.and_then(|rhs| lhs.checked_add(&rhs))),
+        )
+    }
+}
+
+impl<const LIMBS: usize> Add<&Checked<UInt<LIMBS>>> for Checked<UInt<LIMBS>> {
+    type Output = Checked<UInt<LIMBS>>;
+
+    fn add(self, rhs: &Checked<UInt<LIMBS>>) -> Checked<UInt<LIMBS>> {
+        Checked(
+            self.0
+                .and_then(|lhs| rhs.0.and_then(|rhs| lhs.checked_add(&rhs))),
+        )
+    }
+}
+
+impl<const LIMBS: usize> Add<Checked<UInt<LIMBS>>> for &Checked<UInt<LIMBS>> {
+    type Output = Checked<UInt<LIMBS>>;
+
+    fn add(self, rhs: Checked<UInt<LIMBS>>) -> Checked<UInt<LIMBS>> {
+        Checked(
+            self.0
+                .and_then(|lhs| rhs.0.and_then(|rhs| lhs.checked_add(&rhs))),
+        )
+    }
+}
+
+impl<const LIMBS: usize> Add<&Checked<UInt<LIMBS>>> for &Checked<UInt<LIMBS>> {
+    type Output = Checked<UInt<LIMBS>>;
+
+    fn add(self, rhs: &Checked<UInt<LIMBS>>) -> Checked<UInt<LIMBS>> {
+        Checked(
+            self.0
+                .and_then(|lhs| rhs.0.and_then(|rhs| lhs.checked_add(&rhs))),
+        )
+    }
+}
+
+impl<const LIMBS: usize> AddAssign for Checked<UInt<LIMBS>> {
+    fn add_assign(&mut self, other: Self) {
+        *self = *self + other;
+    }
+}
+
+impl<const LIMBS: usize> AddAssign<&Checked<UInt<LIMBS>>> for Checked<UInt<LIMBS>> {
+    fn add_assign(&mut self, other: &Self) {
+        *self = *self + other;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{CheckedAdd, Limb, U128};
+
+    #[test]
+    fn adc_no_carry() {
+        let (res, carry) = U128::ZERO.adc(&U128::ONE, Limb::ZERO);
+        assert_eq!(res, U128::ONE);
+        assert_eq!(carry, Limb::ZERO);
+    }
+
+    #[test]
+    fn adc_with_carry() {
+        let (res, carry) = U128::MAX.adc(&U128::ONE, Limb::ZERO);
+        assert_eq!(res, U128::ZERO);
+        assert_eq!(carry, Limb::ONE);
+    }
+
+    #[test]
+    fn wrapping_add_no_carry() {
+        assert_eq!(U128::ZERO.wrapping_add(&U128::ONE), U128::ONE);
+    }
+
+    #[test]
+    fn wrapping_add_with_carry() {
+        assert_eq!(U128::MAX.wrapping_add(&U128::ONE), U128::ZERO);
+    }
+
+    #[test]
+    fn checked_add_ok() {
+        let result = U128::ZERO.checked_add(&U128::ONE);
+        assert_eq!(result.unwrap(), U128::ONE);
+    }
+
+    #[test]
+    fn checked_add_overflow() {
+        let result = U128::MAX.checked_add(&U128::ONE);
+        assert!(!bool::from(result.is_some()));
+    }
+}