all basic arith ops done (we don't talk about div)

This commit is contained in:
EvilMuffinHa 2022-08-07 18:35:36 -04:00
parent 2e04862fc1
commit f9eb2a1afa
3 changed files with 113 additions and 5 deletions

View File

@ -130,7 +130,14 @@ impl From<SmallUint> for SmallInt {
match s.0 { match s.0 {
SmallUintType::Inline(i) => SmallInt::from(i), SmallUintType::Inline(i) => SmallInt::from(i),
SmallUintType::Heap((r, s)) => { SmallUintType::Heap((r, s)) => {
SmallInt(SmallIntType::Heap((r, isize::try_from(s).unwrap()))) let slice = unsafe { core::slice::from_raw_parts(r, s) };
let mut ret = vec![0; s];
ret.clone_from_slice(slice);
let mut val = ManuallyDrop::new(ret.into_boxed_slice());
SmallInt(SmallIntType::Heap((
val.as_mut_ptr(),
isize::try_from(s).unwrap(),
)))
} }
} }
} }
@ -145,7 +152,11 @@ impl TryFrom<SmallInt> for SmallUint {
SmallIntType::Heap((r, s)) => { SmallIntType::Heap((r, s)) => {
let size = usize::try_from(s).map_err(|_| SmallIntError::ConversionError)?; let size = usize::try_from(s).map_err(|_| SmallIntError::ConversionError)?;
if size > 4 { if size > 4 {
Ok(Self(SmallUintType::Heap((r, size)))) let slice = unsafe { core::slice::from_raw_parts(r, size) };
let mut ret = vec![0; size];
ret.clone_from_slice(slice);
let mut val = ManuallyDrop::new(ret.into_boxed_slice());
Ok(Self(SmallUintType::Heap((val.as_mut_ptr(), size))))
} else { } else {
Ok(Self(SmallUintType::Inline(u128::try_from(value)?))) Ok(Self(SmallUintType::Inline(u128::try_from(value)?)))
} }

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@ -171,9 +171,7 @@ fn add_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
if b <= s { if b <= s {
SmallInt::from(s - b) SmallInt::from(s - b)
} else { } else {
let v = b - s; -SmallInt::from(b - s)
let r = SmallInt::from(v);
-r
} }
} }
@ -279,6 +277,12 @@ fn sub(a: &SmallUint, b: &SmallUint) -> SmallUint {
basic_op!(Sub, sub, SmallUint, sub); basic_op!(Sub, sub, SmallUint, sub);
fn sub_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
a + (-b.clone())
}
basic_op!(Sub, sub, SmallInt, sub_signed);
// Taken from https://github.com/rust-lang/rust/issues/85532#issuecomment-916309635. Credit to // Taken from https://github.com/rust-lang/rust/issues/85532#issuecomment-916309635. Credit to
// AaronKutch. // AaronKutch.
const fn carrying_mul_u128(lhs: u128, rhs: u128, carry: u128) -> (u128, u128) { const fn carrying_mul_u128(lhs: u128, rhs: u128, carry: u128) -> (u128, u128) {
@ -463,3 +467,44 @@ fn mul(a: &SmallUint, b: &SmallUint) -> SmallUint {
} }
basic_op!(Mul, mul, SmallUint, mul); basic_op!(Mul, mul, SmallUint, mul);
fn mul_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
let a_sign;
match &a.0 {
SmallIntType::Inline(i) => a_sign = i.signum() as i8,
SmallIntType::Heap((_, s)) => a_sign = s.signum() as i8,
}
let b_sign;
match &b.0 {
SmallIntType::Inline(i) => b_sign = i.signum() as i8,
SmallIntType::Heap((_, s)) => b_sign = s.signum() as i8,
}
match (a_sign, b_sign) {
x if (x.0 >= 0 && x.1 >= 0) => SmallInt::from(
SmallUint::from_smallint_unsigned(a.clone())
* SmallUint::from_smallint_unsigned(b.clone()),
),
x if (x.0 < 0 && x.1 < 0) => SmallInt::from(
SmallUint::from_smallint_unsigned(a.clone())
* SmallUint::from_smallint_unsigned(b.clone()),
),
x if (x.0 >= 0 && x.1 < 0) => -SmallInt::from(
SmallUint::from_smallint_unsigned(a.clone())
* SmallUint::from_smallint_unsigned(b.clone()),
),
x if (x.0 < 0 && x.1 >= 0) => -SmallInt::from(
SmallUint::from_smallint_unsigned(a.clone())
* SmallUint::from_smallint_unsigned(b.clone()),
),
(_, _) => {
panic!("This shouldn't happen. ");
}
}
}
basic_op!(Mul, mul, SmallInt, mul_signed);

View File

@ -152,6 +152,32 @@ fn test_op_mul_u() {
); );
} }
#[test]
#[cfg(feature = "num-bigint")]
fn test_op_mul_i() {
let i = -SmallInt::from(u128::MAX);
let k = SmallInt::from(u128::MAX);
let q = i * k;
assert_eq!(BigInt::from(&q), -BigInt::from(u128::MAX) * u128::MAX);
let i = -SmallInt::from(u32::MAX);
let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
let q = i * k;
assert_eq!(
BigInt::from(&q),
BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]) * u32::MAX
);
let i = -SmallInt::from(&BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]));
let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
let q = i * k;
assert_eq!(
BigInt::from(&q),
BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1])
* -BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81])
);
}
#[test] #[test]
#[cfg(feature = "num-bigint")] #[cfg(feature = "num-bigint")]
fn test_op_sub_u() { fn test_op_sub_u() {
@ -177,6 +203,32 @@ fn test_op_sub_u() {
); );
} }
#[test]
#[cfg(feature = "num-bigint")]
fn test_op_sub_i() {
let i = -SmallInt::from(u128::MAX);
let k = SmallInt::from(u128::MAX);
let q = i - k;
assert_eq!(BigInt::from(&q), -BigInt::from(u128::MAX) - u128::MAX);
let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
let i = -SmallInt::from(u128::MAX);
let q = k - i;
assert_eq!(
BigInt::from(&q),
BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]) + u128::MAX
);
let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
let i = SmallInt::from(&BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]));
let q = k - i;
assert_eq!(
BigInt::from(&q),
-(BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81])
+ BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]))
);
}
#[test] #[test]
#[cfg(feature = "num-bigint")] #[cfg(feature = "num-bigint")]
fn test_op_and_u() { fn test_op_and_u() {