improve ops.rs, rename BigUint::from_smallint_unsigned to SmallInt::unsigned_abs, etc.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "smallint"
-version = "0.2.1"
+version = "0.2.2"
 edition = "2021"
 authors = ["artofrev"]
 description = "A library for optimized arbitrary precision integers."
@@ -16,3 +16,7 @@ num-bigint = { version = "0.4.3", optional = true }
 
 [dev-dependencies]
 num-bigint = { version = "0.4.3" }
+
+
+[profile.test]
+opt-level = 2

src/bigint.rs

@@ -37,7 +37,7 @@ impl From<&SmallInt> for BigInt {
         match s.0 {
             SmallIntType::Inline(i) => Self::from(i),
             SmallIntType::Heap((r, s)) => {
-                let size = usize::try_from(s.abs()).unwrap();
+                let size = s.unsigned_abs();
                 let sign = s.signum();
                 let slice = unsafe { core::slice::from_raw_parts(r, size) };
                 let bs = match sign {

src/convert.rs

@@ -98,10 +98,10 @@ impl From<u128> for SmallInt {
     }
 }
 
-impl TryFrom<SmallInt> for u128 {
+impl TryFrom<&SmallInt> for u128 {
     type Error = SmallIntError;
 
-    fn try_from(s: SmallInt) -> Result<Self, Self::Error> {
+    fn try_from(s: &SmallInt) -> Result<Self, Self::Error> {
         match s.0 {
             SmallIntType::Inline(i) => {
                 u128::try_from(i).map_err(|_| SmallIntError::ConversionError)
@@ -109,7 +109,7 @@ impl TryFrom<SmallInt> for u128 {
             SmallIntType::Heap((r, s)) => {
                 let mut ret: u128 = 0;
                 let mut bits = 0;
-                let size = usize::try_from(s.abs()).unwrap();
+                let size = s.unsigned_abs();
                 let slice = unsafe { core::slice::from_raw_parts(r, size) };
                 for i in slice {
                     if bits >= 128 {
@@ -125,6 +125,14 @@ impl TryFrom<SmallInt> for u128 {
     }
 }
 
+impl TryFrom<SmallInt> for u128 {
+    type Error = SmallIntError;
+
+    fn try_from(value: SmallInt) -> Result<Self, Self::Error> {
+        Self::try_from(&value)
+    }
+}
+
 impl From<SmallUint> for SmallInt {
     fn from(s: SmallUint) -> Self {
         match s.0 {
@@ -143,10 +151,10 @@ impl From<SmallUint> for SmallInt {
     }
 }
 
-impl TryFrom<SmallInt> for SmallUint {
+impl TryFrom<&SmallInt> for SmallUint {
     type Error = SmallIntError;
 
-    fn try_from(value: SmallInt) -> Result<Self, Self::Error> {
+    fn try_from(value: &SmallInt) -> Result<Self, Self::Error> {
         match value.0 {
             SmallIntType::Inline(i) => Self::try_from(i),
             SmallIntType::Heap((r, s)) => {
@@ -165,23 +173,31 @@ impl TryFrom<SmallInt> for SmallUint {
     }
 }
 
-impl SmallUint {
-    /// Converts a `SmallInt` into a `SmallUint` and drops the sign instead of throwing an error.
-    pub fn from_smallint_unsigned(value: SmallInt) -> Self {
-        match value.0 {
-            SmallIntType::Inline(i) => Self::try_from(i.abs()).unwrap(),
+impl TryFrom<SmallInt> for SmallUint {
+    type Error = SmallIntError;
+
+    fn try_from(value: SmallInt) -> Result<Self, Self::Error> {
+        Self::try_from(&value)
+    }
+}
+
+impl SmallInt {
+    /// Returns the absolute value of the `SmallInt` as a `SmallUint`.
+    pub fn unsigned_abs(&self) -> SmallUint {
+        match self.0 {
+            SmallIntType::Inline(i) => SmallUint::from(i.unsigned_abs()),
             SmallIntType::Heap((r, s)) => {
-                let size = usize::try_from(s.abs()).unwrap();
+                let size = s.unsigned_abs();
                 if size > 4 {
                     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());
-                    Self(SmallUintType::Heap((val.as_mut_ptr(), size)))
+                    SmallUint(SmallUintType::Heap((val.as_mut_ptr(), size)))
                 } else if s >= 0 {
-                    Self(SmallUintType::Inline(u128::try_from(value).unwrap()))
+                    SmallUint(SmallUintType::Inline(u128::try_from(self).unwrap()))
                 } else {
-                    Self(SmallUintType::Inline(u128::try_from(-value).unwrap()))
+                    SmallUint(SmallUintType::Inline(u128::try_from(-self).unwrap()))
                 }
             }
         }

src/logic.rs

@@ -1,15 +1,35 @@
-use crate::smallint::SmallUintType;
-use crate::SmallUint;
+use crate::ops::{add_two_slices, sub_two_slices};
+use crate::smallint::{SmallIntType, SmallUintType};
+use crate::{SmallInt, SmallUint};
+use core::cmp::Ordering;
 use core::mem::ManuallyDrop;
 use core::ops::{BitAnd, BitOr, BitXor};
+use core::ops::{BitAndAssign, BitOrAssign, BitXorAssign};
 
-macro_rules! basic_op {
-    ($imp:ident, $typ:ty, $fun:ident) => {
+macro_rules! logic_op {
+    (
+        $imp:ident, $imp_assign:ident, $typ:ident, $typ_inner:ident, $fun:ident, $fun_assign:ident;
+        $i:ident, $j:ident, $p:ident, $q:ident, $s:ident, $t:ident;
+        $inline_heap:tt, $heap_heap:tt
+    ) => {
         impl<'a, 'b> $imp<&'a $typ> for &'b $typ {
             type Output = $typ;
 
             fn $fun(self, rhs: &$typ) -> Self::Output {
-                $fun(self, rhs)
+                match (&self.0, &rhs.0) {
+                    (&$typ_inner::Inline($i), &$typ_inner::Inline($j)) => {
+                        $typ($typ_inner::Inline($i.$fun($j)))
+                    }
+
+                    (&$typ_inner::Inline($i), &$typ_inner::Heap(($p, $s)))
+                    | (&$typ_inner::Heap(($p, $s)), &$typ_inner::Inline($i)) => {
+                        $inline_heap
+                    }
+
+                    (&$typ_inner::Heap(($p, $s)), &$typ_inner::Heap(($q, $t))) => {
+                        $heap_heap
+                    }
+                }
             }
         }
 
@@ -36,168 +56,382 @@ macro_rules! basic_op {
                 (&self).$fun(&rhs)
             }
         }
+
+        impl<'a> $imp_assign<&'a $typ> for $typ {
+            fn $fun_assign(&mut self, rhs: &'a $typ) {
+                *self = (&*self).$fun(rhs);
+            }
+        }
+
+        impl $imp_assign<$typ> for $typ {
+            fn $fun_assign(&mut self, rhs: $typ) {
+                *self = (&*self).$fun(rhs);
+            }
+        }
+    };
+    (
+        $imp:ident, $imp_assign:ident, $typ:ident, $typ_inner:ident, $fun:ident, $fun_assign:ident;
+        $i:ident, $j:ident, $p:ident, $q:ident, $s:ident, $t:ident, $slice:ident, $slice1:ident, $slice2:ident, $min:ident, $res:ident;
+        $inline_heap_inner:tt, $heap_heap_create_res:tt, $heap_heap_return:tt
+    ) => {
+        logic_op! {
+            $imp, $imp_assign, $typ, $typ_inner, $fun, $fun_assign;
+            $i, $j, $p, $q, $s, $t;
+            {
+                let $slice = unsafe { core::slice::from_raw_parts($p, $s) };
+
+                $inline_heap_inner
+            },
+            {
+                let $slice1 = unsafe { core::slice::from_raw_parts($p, $s) };
+                let $slice2 = unsafe { core::slice::from_raw_parts($q, $t) };
+
+                let $min = std::cmp::min($slice1.len(), $slice2.len());
+
+                #[allow(unused_mut)]
+                let mut $res = $heap_heap_create_res;
+
+                $heap_heap_return
+            }
+        }
     };
 }
 
-fn bitand(a: &SmallUint, b: &SmallUint) -> SmallUint {
-    match (&a.0, &b.0) {
-        (&SmallUintType::Inline(i), &SmallUintType::Inline(j)) => {
-            SmallUint(SmallUintType::Inline(i & j))
-        }
 
-        (&SmallUintType::Inline(i), &SmallUintType::Heap((r, s)))
-        | (&SmallUintType::Heap((r, s)), &SmallUintType::Inline(i)) => {
-            let slice = unsafe { core::slice::from_raw_parts(r, s) };
-            let mut j = 0u128;
+macro_rules! heap_to_inline {
+    ($typ_inline:ident; $slice:ident) => {
+        let mut j = 0;
         for i in 0..4 {
             j <<= 32;
-
-                j |= slice[3 - i] as u128;
+            j |= $slice[3 - i] as $typ_inline;
+        }
+        j
     }
-            SmallUint(SmallUintType::Inline(i & j))
 }
 
-        (&SmallUintType::Heap((r, s)), &SmallUintType::Heap((i, j))) => {
-            let slice1 = unsafe { core::slice::from_raw_parts(r, s) };
-            let slice2 = unsafe { core::slice::from_raw_parts(i, j) };
+macro_rules! inline_heap_to_inline {
+    ($fun:ident, $typ:ident, $typ_inner:ident, $typ_inline:ident; $i:ident, $slice:ident) => {
+        let j = { heap_to_inline! { $typ_inline; $slice } };
+        $typ($typ_inner::Inline($i.$fun(j)))
+    }
+}
 
+macro_rules! inline_heap_to_heap {
+    ($fun_assign:ident, $typ:ident, $typ_inner:ident; $i:ident, $slice:ident) => {
+        let mut retvec = $slice.to_vec();
+
+        let mut v = $i;
+        #[allow(clippy::needless_range_loop)]
+        for r in 0..4 {
+            retvec[r].$fun_assign(v as u32);
+
+            v >>= 32;
+        }
+
+        let mut retslice = ManuallyDrop::new(retvec.into_boxed_slice());
+
+        $typ($typ_inner::Heap((retslice.as_mut_ptr(), retslice.len().try_into().unwrap())))
+    }
+}
+
+
+macro_rules! heap_heap_create_res_shortest {
+    ($fun:ident; $slice1:ident, $slice2:ident, $min:ident) => {
+        let mut res = Vec::with_capacity($min);
+        for l in 0..$min {
+            res.push($slice1[l].$fun($slice2[l]));
+        }
+        res
+    }
+}
+
+macro_rules! heap_heap_create_res_longest {
+    ($fun:ident; $slice1:ident, $slice2:ident, $min:ident) => {
+        let mut res = if $slice1.len() > $slice2.len() {
+            $slice1.to_vec()
+        } else {
+            $slice2.to_vec()
+        };
+        for l in 0..$min {
+            res[l] = $slice1[l].$fun($slice2[l]);
+        }
+        res
+    }
+}
+
+
+macro_rules! return_heap_inner {
+    ($typ:ident, $typ_inner:ident; $res:ident) => {
+        let mut slice = ManuallyDrop::new($res);
+        $typ($typ_inner::Heap((slice.as_mut_ptr(), slice.len().try_into().unwrap())))
+    }
+}
+
+macro_rules! return_heap_inner_neg {
+    ($typ:ident, $typ_inner:ident; $res:ident) => {
+        let mut slice = ManuallyDrop::new($res);
+        $typ($typ_inner::Heap((slice.as_mut_ptr(), -isize::try_from(slice.len()).unwrap())))
+    }
+}
+
+macro_rules! return_heap {
+    ($typ:ident, $typ_inner:ident; $res:ident) => {
+        let res = $res.into_boxed_slice();
+        return_heap_inner! { $typ, $typ_inner; res }
+    }
+}
+
+macro_rules! return_heap_neg {
+    ($typ:ident, $typ_inner:ident; $res:ident) => {
+        let res = $res.into_boxed_slice();
+        return_heap_inner_neg! { $typ, $typ_inner; res }
+    }
+}
+
+macro_rules! heap_heap_return_any {
+    ($typ:ident, $typ_inner:ident, $typ_inline:ident; $res:ident) => {
+        while $res.len() != 1 && $res[$res.len() - 1] == 0 {
+            $res.pop();
+        }
+
+        if $res.len() <= 4 {
+            let mut r = 0;
+            for t in 0..$res.len() {
+                r <<= 32;
+                r |= $res[$res.len() - 1 - t] as $typ_inline;
+            }
+            $typ($typ_inner::Inline(r))
+        } else {
+            let mut slice = ManuallyDrop::new($res.into_boxed_slice());
+            $typ($typ_inner::Heap((slice.as_mut_ptr(), slice.len().try_into().unwrap())))
+        }
+    }
+}
+
+logic_op! {
+    BitAnd, BitAndAssign, SmallUint, SmallUintType, bitand, bitand_assign;
+    i, j, p, q, s, t, slice, slice1, slice2, min, res;
+    { inline_heap_to_inline! { bitand, SmallUint, SmallUintType, u128; i, slice } },
+    { heap_heap_create_res_shortest! { bitand; slice1, slice2, min } },
+    { heap_heap_return_any! { SmallUint, SmallUintType, u128; res } }
+}
+
+logic_op! {
+    BitOr, BitOrAssign, SmallUint, SmallUintType, bitor, bitor_assign;
+    i, j, p, q, s, t, slice, slice1, slice2, min, res;
+    { inline_heap_to_heap! { bitor_assign, SmallUint, SmallUintType; i, slice } },
+    { heap_heap_create_res_longest! { bitor; slice1, slice2, min }},
+    { return_heap! { SmallUint, SmallUintType; res } }
+}
+
+logic_op! {
+    BitXor, BitXorAssign, SmallUint, SmallUintType, bitxor, bitxor_assign;
+    i, j, p, q, s, t, slice, slice1, slice2, min, res;
+    { inline_heap_to_heap! { bitxor_assign, SmallUint, SmallUintType; i, slice } },
+    { heap_heap_create_res_longest! { bitxor; slice1, slice2, min }},
+    { heap_heap_return_any! { SmallUint, SmallUintType, u128; res } }
+}
+
+
+
+fn bitor_two_slices(slice1: &[u32], slice2: &[u32]) -> Vec<u32> {
+    let mut result = if slice1.len() > slice2.len() {
+        slice1.to_vec()
+    } else {
+        slice2.to_vec()
+    };
+    for l in 0..std::cmp::min(slice1.len(), slice2.len()) {
+        result[l] = slice1[l] | slice2[l];
+    }
+    result
+}
+
+fn bitand_two_slices_mixed_sign(positive: &[u32], negative: &[u32]) -> Vec<u32> {
+    // a & (-b) = (a | (b - 1)) + 1 - b
+    // 0 is not negative, so we can ignore it
+    let sub1 = sub_two_slices(negative, &[1]);
+    let or = bitor_two_slices(positive, &sub1);
+    let add = add_two_slices(&or, &[1]);
+    let sub2 = sub_two_slices(&add, negative);
+    sub2
+}
+
+fn bitand_two_slices(slice1: &[u32], slice2: &[u32]) -> Vec<u32> {
+    let mut result = if slice1.len() > slice2.len() {
+        slice1.to_vec()
+    } else {
+        slice2.to_vec()
+    };
+    for l in 0..std::cmp::min(slice1.len(), slice2.len()) {
+        result[l] = slice1[l] | slice2[l];
+    }
+    result
+}
+
+fn bitor_two_slices_mixed_sign(positive: &[u32], negative: &[u32]) -> Vec<u32> {
+    // a | (-b) = (a & (b - 1)) + 1 - b
+    // 0 is not negative, so we can ignore it
+    let sub1 = sub_two_slices(negative, &[1]);
+    let or = bitand_two_slices(positive, &sub1);
+    let add = add_two_slices(&or, &[1]);
+    let sub2 = sub_two_slices(&add, negative);
+    sub2
+}
+
+logic_op! {
+    BitAnd, BitAndAssign, SmallInt, SmallIntType, bitand, bitand_assign;
+    i, j, p, q, s, t;
+    {
+        let slice = unsafe { core::slice::from_raw_parts(p, s.unsigned_abs()) };
+        match (i.cmp(&0), s.cmp(&0)) {
+            (Ordering::Equal, _) => SmallInt(SmallIntType::Inline(0)),
+            (Ordering::Greater, Ordering::Greater) => {
+                let j = { heap_to_inline! { i128; slice } };
+                SmallInt(SmallIntType::Inline(i & j))
+            },
+            (Ordering::Greater, Ordering::Less) => {
+                let j = { heap_to_inline! { i128; slice } };
+                SmallInt(SmallIntType::Inline(i & -j))
+            },
+            (Ordering::Less, Ordering::Greater) => {
+                let mut res = <Box<[u32]>>::from(slice);
+                let mut inline = i;
+                for idx in 0..4 {
+                    res[idx] &= inline as u32;
+                    inline >>= 32;
+                }
+                return_heap_inner! { SmallInt, SmallIntType; res }
+            },
+            (Ordering::Less, Ordering::Less) => {
+                let mut res = <Box<[u32]>>::from(slice);
+                let j = { heap_to_inline! { i128; slice } };
+                let lo = (i & j.wrapping_neg()).wrapping_neg();
+                let mut lo_remaining = lo;
+                for idx in 0..4 {
+                    res[idx] = lo_remaining as u32;
+                    lo_remaining >>= 32;
+                }
+
+                if lo == 0 && j != 0 {
+                    let res2 = add_two_slices(&res, &[0, 0, 0, 0, 1]);
+                    return_heap_neg! { SmallInt, SmallIntType; res2 }
+                } else {
+                    return_heap_inner_neg! { SmallInt, SmallIntType; res }
+                }
+            },
+            (_, Ordering::Equal) => unreachable!("0 must be inline"),
+        }
+    },
+    {
+        let slice1 = unsafe { core::slice::from_raw_parts(p, s.unsigned_abs()) };
+        let slice2 = unsafe { core::slice::from_raw_parts(q, t.unsigned_abs()) };
+        match (s.cmp(&0), t.cmp(&0)) {
+            (Ordering::Greater, Ordering::Greater) => {
                 let min = std::cmp::min(slice1.len(), slice2.len());
 
-            let mut res = Vec::with_capacity(min);
-
-            for l in 0..min {
-                res.push(slice1[l] & slice2[l]);
-            }
-
-            while res.len() != 1 && res[res.len() - 1] == 0 {
-                res.pop();
-            }
-
-            if res.len() <= 4 {
-                let mut r = 0u128;
-                for t in 0..res.len() {
-                    r <<= 32;
-                    r |= res[res.len() - 1 - t] as u128;
-                }
-                SmallUint(SmallUintType::Inline(r))
-            } else {
-                let mut slice = ManuallyDrop::new(res.into_boxed_slice());
-                SmallUint(SmallUintType::Heap((slice.as_mut_ptr(), slice.len())))
-            }
-        }
-    }
-}
-
-basic_op!(BitAnd, SmallUint, bitand);
-
-fn bitor(a: &SmallUint, b: &SmallUint) -> SmallUint {
-    match (&a.0, &b.0) {
-        (&SmallUintType::Inline(i), &SmallUintType::Inline(j)) => {
-            SmallUint(SmallUintType::Inline(i | j))
-        }
-        (&SmallUintType::Inline(i), &SmallUintType::Heap((r, s)))
-        | (&SmallUintType::Heap((r, s)), &SmallUintType::Inline(i)) => {
-            let slice = unsafe { core::slice::from_raw_parts(r, s) };
-
-            let mut retvec = slice.to_vec();
-
-            let mut v = i;
-            #[allow(clippy::needless_range_loop)]
-            for r in 0..4 {
-                retvec[r] |= v as u32;
-
-                v >>= 32;
-            }
-
-            let mut retslice = ManuallyDrop::new(retvec.into_boxed_slice());
-
-            SmallUint(SmallUintType::Heap((retslice.as_mut_ptr(), retslice.len())))
-        }
-
-        (&SmallUintType::Heap((r, s)), &SmallUintType::Heap((i, j))) => {
-            let slice1 = unsafe { core::slice::from_raw_parts(r, s) };
-            let slice2 = unsafe { core::slice::from_raw_parts(i, j) };
-
-            let m = std::cmp::min(slice1.len(), slice2.len());
-
-            let mut retvec;
-            if slice1.len() > slice2.len() {
-                retvec = slice1.to_vec();
-            } else {
-                retvec = slice2.to_vec();
-            }
-
-            for t in 0..m {
-                retvec[t] = slice1[t] | slice2[t];
-            }
-
-            let mut slice = ManuallyDrop::new(retvec.into_boxed_slice());
-
-            SmallUint(SmallUintType::Heap((slice.as_mut_ptr(), slice.len())))
+                #[allow(unused_mut)]
+                let mut res = { heap_heap_create_res_shortest! { bitand; slice1, slice2, min } };
+                // TODO: shrink if needed, sometimes to Inline
+                return_heap! { SmallInt, SmallIntType; res }
+            },
+            (Ordering::Greater, Ordering::Less) => {
+                let res = bitand_two_slices_mixed_sign(slice1, slice2);
+                return_heap! { SmallInt, SmallIntType; res }
+            },
+            (Ordering::Less, Ordering::Greater) => {
+                let res = bitand_two_slices_mixed_sign(slice2, slice1);
+                return_heap! { SmallInt, SmallIntType; res }
+            },
+            (Ordering::Less, Ordering::Less) => {
+                // (-a) & (-b) = -(((a-1) | (b-1)) + 1)
+                // 0 is not negative, so we can ignore it
+                let sub1 = sub_two_slices(slice1, &[1]);
+                let sub2 = sub_two_slices(slice2, &[1]);
+                let tmp = bitor_two_slices(&sub1, &sub2);
+                let res = add_two_slices(&tmp, &[1]);
+                return_heap_neg! { SmallInt, SmallIntType; res }
+            },
+            (Ordering::Equal, _) | (_, Ordering::Equal) => unreachable!("0 must be inline"),
         }
     }
 }
 
-basic_op!(BitOr, SmallUint, bitor);
-
-fn bitxor(a: &SmallUint, b: &SmallUint) -> SmallUint {
-    match (&a.0, &b.0) {
-        (&SmallUintType::Inline(i), &SmallUintType::Inline(j)) => {
-            SmallUint(SmallUintType::Inline(i ^ j))
-        }
-        (&SmallUintType::Inline(i), &SmallUintType::Heap((r, s)))
-        | (&SmallUintType::Heap((r, s)), &SmallUintType::Inline(i)) => {
-            let slice = unsafe { core::slice::from_raw_parts(r, s) };
-
-            let mut retvec = slice.to_vec();
-
-            let mut v = i;
-            #[allow(clippy::needless_range_loop)]
-            for r in 0..4 {
-                retvec[r] ^= v as u32;
-
-                v >>= 32;
-            }
-
-            let mut retslice = ManuallyDrop::new(retvec.into_boxed_slice());
-
-            SmallUint(SmallUintType::Heap((retslice.as_mut_ptr(), retslice.len())))
-        }
-
-        (&SmallUintType::Heap((r, s)), &SmallUintType::Heap((i, j))) => {
-            let slice1 = unsafe { core::slice::from_raw_parts(r, s) };
-            let slice2 = unsafe { core::slice::from_raw_parts(i, j) };
-
-            let m = std::cmp::min(slice1.len(), slice2.len());
-
-            let mut res;
-            if slice1.len() > slice2.len() {
-                res = slice1.to_vec();
-            } else {
-                res = slice2.to_vec();
-            }
-
-            for t in 0..m {
-                res[t] = slice1[t] ^ slice2[t];
-            }
-
-            while res.len() != 1 && res[res.len() - 1] == 0 {
-                res.pop();
-            }
-
-            if res.len() <= 4 {
-                let mut r = 0u128;
-                for t in 0..res.len() {
-                    r <<= 32;
-                    r |= res[res.len() - 1 - t] as u128;
-                }
-                SmallUint(SmallUintType::Inline(r))
-            } else {
-                let mut slice = ManuallyDrop::new(res.into_boxed_slice());
-                SmallUint(SmallUintType::Heap((slice.as_mut_ptr(), slice.len())))
-            }
-        }
-    }
-}
-
-basic_op!(BitXor, SmallUint, bitxor);
+// logic_op! {
+//     BitOr, BitOrAssign, SmallInt, SmallIntType, bitor, bitor_assign;
+//     i, j, p, q, s, t;
+//     {
+//         let slice = unsafe { core::slice::from_raw_parts(p, s.unsigned_abs()) };
+//         match (i.cmp(&0), s.cmp(&0)) {
+//             (Ordering::Equal, _) => {
+//                 let mut slice = ManuallyDrop::new(<Box<[_]>>::from(slice));
+//                 SmallInt(SmallIntType::Heap((slice.as_mut_ptr(), s)))
+//             },
+//             (Ordering::Greater, Ordering::Greater) => {
+//                 inline_heap_to_heap! { bitor_assign, SmallInt, SmallIntType; i, slice }
+//             },
+//             (Ordering::Greater, Ordering::Less) => {
+//                 let mut res = <Box<[u32]>>::from(slice);
+//                 let mut inline = i as u128;
+//                 for idx in 0..4 {
+//                     res[idx] = ((res[idx] as i32).wrapping_neg() | (inline as i32).wrapping_neg()).wrapping_neg() as u32;
+//                     inline >>= 32;
+//                 }
+//                 return_heap_inner_neg! { SmallInt, SmallIntType; res }
+//             },
+//             (Ordering::Less, Ordering::Greater) => {
+//                 let j = { heap_to_inline! { i128; slice } };
+//                 SmallInt(SmallIntType::Inline(i | -j))
+//             },
+//             (Ordering::Less, Ordering::Less) => {
+//                 let mut res = <Box<[u32]>>::from(slice);
+//                 let j = { heap_to_inline! { i128; slice } };
+//                 let lo = (i | j.wrapping_neg()).wrapping_neg();
+//                 let mut lo_remaining = lo;
+//                 for idx in 0..4 {
+//                     res[idx] = lo_remaining as u32;
+//                     lo_remaining >>= 32;
+//                 }
+//
+//                 if lo == 0 && j != 0 {
+//                     let res2 = add_two_slices(&res, &[0, 0, 0, 0, 1]);
+//                     return_heap_neg! { SmallInt, SmallIntType; res2 }
+//                 } else {
+//                     return_heap_inner_neg! { SmallInt, SmallIntType; res }
+//                 }
+//             },
+//             (_, Ordering::Equal) => unreachable!("0 must be inline"),
+//         }
+//     },
+//     {
+//         let slice1 = unsafe { core::slice::from_raw_parts(p, s.unsigned_abs()) };
+//         let slice2 = unsafe { core::slice::from_raw_parts(q, t.unsigned_abs()) };
+//         match (s.cmp(&0), t.cmp(&0)) {
+//             (Ordering::Greater, Ordering::Greater) => {
+//                 let min = std::cmp::min(slice1.len(), slice2.len());
+//
+//                 #[allow(unused_mut)]
+//                 let mut res = { heap_heap_create_res_longest! { bitor; slice1, slice2, min } };
+//
+//                 return_heap! { SmallInt, SmallIntType; res }
+//             },
+//             (Ordering::Greater, Ordering::Less) => {
+//                 let res = bitor_two_slices_mixed_sign(slice1, slice2);
+//                 return_heap! { SmallInt, SmallIntType; res }
+//             },
+//             (Ordering::Less, Ordering::Greater) => {
+//                 let res = bitor_two_slices_mixed_sign(slice2, slice1);
+//                 return_heap! { SmallInt, SmallIntType; res }
+//             },
+//             (Ordering::Less, Ordering::Less) => {
+//                 // (-a) | (-b) = -(((a-1) & (b-1)) + 1)
+//                 // 0 is not negative, so we can ignore it
+//                 let sub1 = sub_two_slices(slice1, &[1]);
+//                 let sub2 = sub_two_slices(slice2, &[1]);
+//                 let tmp = bitand_two_slices(&sub1, &sub2);
+//                 let res = add_two_slices(&tmp, &[1]);
+//                 return_heap_neg! { SmallInt, SmallIntType; res }
+//             },
+//             (Ordering::Equal, _) | (_, Ordering::Equal) => unreachable!("0 must be inline"),
+//         }
+//     }
+// }

src/ops.rs

@@ -1,16 +1,25 @@
 use crate::smallint::{SmallIntType, SmallUintType};
 use crate::{SmallInt, SmallUint};
 use core::mem::ManuallyDrop;
-use core::ops::{Add, Mul, Neg, Sub};
+use core::ops::{Add, Div, Mul, Neg, Sub};
+use core::ops::{AddAssign, DivAssign, MulAssign, SubAssign};
 
-impl Neg for SmallInt {
-    type Output = Self;
+impl Neg for &SmallInt {
+    type Output = SmallInt;
 
-    fn neg(self) -> Self::Output {
+    fn neg(self) -> SmallInt {
         match self.0 {
-            SmallIntType::Inline(i) => SmallInt(SmallIntType::Inline(-i)),
+            SmallIntType::Inline(i) => {
+                if let Some(n) = i.checked_neg() {
+                    SmallInt(SmallIntType::Inline(n))
+                } else {
+                    // -i128::MIN = i128::MAX + 1 = 0x8000...
+                    let mut val = ManuallyDrop::new(Box::new([0, 0, 0, 0x80_00_00_00]));
+                    SmallInt(SmallIntType::Heap((val.as_mut_ptr(), 4)))
+                }
+            },
             SmallIntType::Heap((r, s)) => {
-                let size = usize::try_from(s.abs()).unwrap();
+                let size = s.unsigned_abs();
                 let slice = unsafe { core::slice::from_raw_parts(r, size) };
                 let mut ret = vec![0; size];
                 ret.clone_from_slice(slice);
@@ -21,6 +30,14 @@ impl Neg for SmallInt {
     }
 }
 
+impl Neg for SmallInt {
+    type Output = SmallInt;
+
+    fn neg(self) -> SmallInt {
+        (&self).neg()
+    }
+}
+
 macro_rules! basic_op {
     ($imp:ident, $lower:ident, $typ:ty, $fun:ident) => {
         impl<'a, 'b> $imp<&'a $typ> for &'b $typ {
@@ -57,7 +74,7 @@ macro_rules! basic_op {
     };
 }
 
-fn add_two_slices(slice1: &[u32], slice2: &[u32]) -> Vec<u32> {
+pub(crate) fn add_two_slices(slice1: &[u32], slice2: &[u32]) -> Vec<u32> {
     let s = slice1.len();
     let j = slice2.len();
 
@@ -142,6 +159,18 @@ fn add(a: &SmallUint, b: &SmallUint) -> SmallUint {
 
 basic_op!(Add, add, SmallUint, add);
 
+impl<'a> AddAssign<&'a SmallUint> for SmallUint {
+    fn add_assign(&mut self, rhs: &'a SmallUint) {
+        *self = self.clone() + rhs;
+    }
+}
+
+impl AddAssign<SmallUint> for SmallUint {
+    fn add_assign(&mut self, rhs: SmallUint) {
+        *self = self.clone() + rhs;
+    }
+}
+
 fn add_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
     let a_sign;
     match &a.0 {
@@ -157,17 +186,17 @@ fn add_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
 
     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()),
+            a.unsigned_abs()
+                + b.unsigned_abs(),
         ),
         x if (x.0 < 0 && x.1 < 0) => -SmallInt::from(
-            SmallUint::from_smallint_unsigned(a.clone())
-                + SmallUint::from_smallint_unsigned(b.clone()),
+            a.unsigned_abs()
+                + b.unsigned_abs(),
         ),
 
         x if (x.0 >= 0 && x.1 < 0) => {
-            let s = SmallUint::from_smallint_unsigned(a.clone());
-            let b = SmallUint::from_smallint_unsigned(b.clone());
+            let s = a.unsigned_abs();
+            let b = b.unsigned_abs();
             if b <= s {
                 SmallInt::from(s - b)
             } else {
@@ -176,8 +205,8 @@ fn add_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
         }
 
         x if (x.0 < 0 && x.1 >= 0) => {
-            let s = SmallUint::from_smallint_unsigned(a.clone());
-            let b = SmallUint::from_smallint_unsigned(b.clone());
+            let s = a.unsigned_abs();
+            let b = b.unsigned_abs();
             if s <= b {
                 SmallInt::from(b - s)
             } else {
@@ -192,7 +221,19 @@ fn add_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
 
 basic_op!(Add, add, SmallInt, add_signed);
 
-fn sub_two_slices(slice1: &[u32], slice2: &[u32]) -> Vec<u32> {
+impl<'a> AddAssign<&'a SmallInt> for SmallInt {
+    fn add_assign(&mut self, rhs: &'a SmallInt) {
+        *self = self.clone() + rhs;
+    }
+}
+
+impl AddAssign<SmallInt> for SmallInt {
+    fn add_assign(&mut self, rhs: SmallInt) {
+        *self = self.clone() + rhs;
+    }
+}
+
+pub(crate) fn sub_two_slices(slice1: &[u32], slice2: &[u32]) -> Vec<u32> {
     let b = slice1.len();
     let s = slice2.len();
 
@@ -277,12 +318,36 @@ fn sub(a: &SmallUint, b: &SmallUint) -> SmallUint {
 
 basic_op!(Sub, sub, SmallUint, sub);
 
+impl<'a> SubAssign<&'a SmallUint> for SmallUint {
+    fn sub_assign(&mut self, rhs: &'a SmallUint) {
+        *self = self.clone() - rhs;
+    }
+}
+
+impl SubAssign<SmallUint> for SmallUint {
+    fn sub_assign(&mut self, rhs: SmallUint) {
+        *self = self.clone() - rhs;
+    }
+}
+
 fn sub_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
     a + (-b.clone())
 }
 
 basic_op!(Sub, sub, SmallInt, sub_signed);
 
+impl<'a> SubAssign<&'a SmallInt> for SmallInt {
+    fn sub_assign(&mut self, rhs: &'a SmallInt) {
+        *self = self.clone() - rhs;
+    }
+}
+
+impl SubAssign<SmallInt> for SmallInt {
+    fn sub_assign(&mut self, rhs: SmallInt) {
+        *self = self.clone() - rhs;
+    }
+}
+
 // Taken from https://github.com/rust-lang/rust/issues/85532#issuecomment-916309635. Credit to
 // AaronKutch.
 const fn carrying_mul_u128(lhs: u128, rhs: u128, carry: u128) -> (u128, u128) {
@@ -468,6 +533,18 @@ fn mul(a: &SmallUint, b: &SmallUint) -> SmallUint {
 
 basic_op!(Mul, mul, SmallUint, mul);
 
+impl<'a> MulAssign<&'a SmallUint> for SmallUint {
+    fn mul_assign(&mut self, rhs: &'a SmallUint) {
+        *self = self.clone() * rhs;
+    }
+}
+
+impl MulAssign<SmallUint> for SmallUint {
+    fn mul_assign(&mut self, rhs: SmallUint) {
+        *self = self.clone() * rhs;
+    }
+}
+
 fn mul_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
     let a_sign;
     match &a.0 {
@@ -483,22 +560,22 @@ fn mul_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
 
     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()),
+            a.unsigned_abs()
+                * b.unsigned_abs(),
         ),
         x if (x.0 < 0 && x.1 < 0) => SmallInt::from(
-            SmallUint::from_smallint_unsigned(a.clone())
-                * SmallUint::from_smallint_unsigned(b.clone()),
+            a.unsigned_abs()
+                * b.unsigned_abs(),
         ),
 
         x if (x.0 >= 0 && x.1 < 0) => -SmallInt::from(
-            SmallUint::from_smallint_unsigned(a.clone())
-                * SmallUint::from_smallint_unsigned(b.clone()),
+            a.unsigned_abs()
+                * b.unsigned_abs(),
         ),
 
         x if (x.0 < 0 && x.1 >= 0) => -SmallInt::from(
-            SmallUint::from_smallint_unsigned(a.clone())
-                * SmallUint::from_smallint_unsigned(b.clone()),
+            a.unsigned_abs()
+                * b.unsigned_abs(),
         ),
 
         (_, _) => {
@@ -508,3 +585,51 @@ fn mul_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
 }
 
 basic_op!(Mul, mul, SmallInt, mul_signed);
+
+impl<'a> MulAssign<&'a SmallInt> for SmallInt {
+    fn mul_assign(&mut self, rhs: &'a SmallInt) {
+        *self = self.clone() * rhs;
+    }
+}
+
+impl MulAssign<SmallInt> for SmallInt {
+    fn mul_assign(&mut self, rhs: SmallInt) {
+        *self = self.clone() * rhs;
+    }
+}
+
+fn div(_a: &SmallUint, _b: &SmallUint) -> SmallUint {
+    todo!()
+}
+
+basic_op!(Div, div, SmallUint, div);
+
+impl<'a> DivAssign<&'a SmallUint> for SmallUint {
+    fn div_assign(&mut self, rhs: &'a SmallUint) {
+        *self = self.clone() / rhs;
+    }
+}
+
+impl DivAssign<SmallUint> for SmallUint {
+    fn div_assign(&mut self, rhs: SmallUint) {
+        *self = self.clone() / rhs;
+    }
+}
+
+fn div_signed(_a: &SmallInt, _b: &SmallInt) -> SmallInt {
+    todo!()
+}
+
+basic_op!(Div, div, SmallInt, div_signed);
+
+impl<'a> DivAssign<&'a SmallInt> for SmallInt {
+    fn div_assign(&mut self, rhs: &'a SmallInt) {
+        *self = self.clone() / rhs;
+    }
+}
+
+impl DivAssign<SmallInt> for SmallInt {
+    fn div_assign(&mut self, rhs: SmallInt) {
+        *self = self.clone() / rhs;
+    }
+}

src/ord.rs

@@ -6,23 +6,12 @@ use std::cmp::Ordering;
 impl PartialEq for SmallUint {
     fn eq(&self, other: &SmallUint) -> bool {
         match (&self.0, &other.0) {
-            (SmallUintType::Inline(i), SmallUintType::Inline(j)) => i.eq(j),
-            (SmallUintType::Heap((r, s)), SmallUintType::Heap((i, j))) => match j.cmp(s) {
-                Ordering::Greater => false,
-                Ordering::Less => false,
-                Ordering::Equal => {
-                    let slice1 = unsafe { core::slice::from_raw_parts(r, *s) };
-                    let slice2 = unsafe { core::slice::from_raw_parts(i, *j) };
-                    for i in 0..*s {
-                        match slice1[s - 1 - i].cmp(&slice2[s - 1 - i]) {
-                            Ordering::Less => return false,
-                            Ordering::Greater => return false,
-                            _ => {}
+            (SmallUintType::Inline(i), SmallUintType::Inline(j)) => i == j,
+            (SmallUintType::Heap((p, s)), SmallUintType::Heap((q, t))) => {
+                let slice1 = unsafe { core::slice::from_raw_parts(*p, *s) };
+                let slice2 = unsafe { core::slice::from_raw_parts(*q, *t) };
+                slice1 == slice2
             }
-                    }
-                    true
-                }
-            },
             (_, _) => false,
         }
     }
@@ -32,57 +21,45 @@ impl Eq for SmallUint {}
 
 impl PartialOrd for SmallUint {
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for SmallUint {
+    fn cmp(&self, other: &Self) -> Ordering {
         match (&self.0, &other.0) {
-            (SmallUintType::Inline(i), SmallUintType::Inline(j)) => Some(i.cmp(j)),
-            (SmallUintType::Inline(_), SmallUintType::Heap((_, _))) => Some(Ordering::Less),
-            (SmallUintType::Heap((_, _)), SmallUintType::Inline(_)) => Some(Ordering::Greater),
-            (SmallUintType::Heap((r, s)), SmallUintType::Heap((i, j))) => match j.cmp(s) {
-                Ordering::Greater => Some(Ordering::Less),
-                Ordering::Less => Some(Ordering::Greater),
+            (SmallUintType::Inline(i), SmallUintType::Inline(j)) => i.cmp(j),
+            (SmallUintType::Inline(_), SmallUintType::Heap((_, _))) => Ordering::Less,
+            (SmallUintType::Heap((_, _)), SmallUintType::Inline(_)) => Ordering::Greater,
+            (SmallUintType::Heap((p, s)), SmallUintType::Heap((q, t))) => match s.cmp(t) {
                 Ordering::Equal => {
-                    let slice1 = unsafe { core::slice::from_raw_parts(r, *s) };
-                    let slice2 = unsafe { core::slice::from_raw_parts(i, *j) };
+                    let slice1 = unsafe { core::slice::from_raw_parts(*p, *s) };
+                    let slice2 = unsafe { core::slice::from_raw_parts(*q, *t) };
                     for i in 0..*s {
                         match slice1[s - 1 - i].cmp(&slice2[s - 1 - i]) {
-                            Ordering::Less => return Some(Ordering::Less),
-                            Ordering::Greater => return Some(Ordering::Greater),
-                            _ => {}
+                            Ordering::Equal => {}
+                            o => return o,
                         }
                     }
-                    Some(Ordering::Equal)
+                    Ordering::Equal
+                }
+                o => o,
             }
-            },
         }
     }
 }
 
 impl PartialEq for SmallInt {
-    fn eq(&self, other: &Self) -> bool {
+    fn eq(&self, other: &SmallInt) -> bool {
         match (&self.0, &other.0) {
-            (SmallIntType::Inline(i), SmallIntType::Inline(j)) => i.eq(j),
-            (SmallIntType::Heap((r, s)), SmallIntType::Heap((i, j))) => {
-                if s.signum() != j.signum() {
+            (SmallIntType::Inline(i), SmallIntType::Inline(j)) => i == j,
+            (SmallIntType::Heap((p, s)), SmallIntType::Heap((q, t))) => {
+                if s != t {  // need to compare signs, at minimum
                     return false;
                 }
-
-                match j.cmp(s) {
-                    Ordering::Greater => false,
-                    Ordering::Less => false,
-                    Ordering::Equal => {
-                        let us = usize::try_from(s.abs()).unwrap();
-                        let uj = usize::try_from(j.abs()).unwrap();
-                        let slice1 = unsafe { core::slice::from_raw_parts(r, us) };
-                        let slice2 = unsafe { core::slice::from_raw_parts(i, uj) };
-                        for i in 0..*s {
-                            match slice1[(s - 1 - i) as usize].cmp(&slice2[(s - 1 - i) as usize]) {
-                                Ordering::Less => return false,
-                                Ordering::Greater => return false,
-                                _ => {}
-                            }
-                        }
-                        true
-                    }
-                }
+                let slice1 = unsafe { core::slice::from_raw_parts(*p, s.unsigned_abs()) };
+                let slice2 = unsafe { core::slice::from_raw_parts(*q, t.unsigned_abs()) };
+                slice1 == slice2
             }
             (_, _) => false,
         }
@@ -93,36 +70,27 @@ impl Eq for SmallInt {}
 
 impl PartialOrd for SmallInt {
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        let a_sign;
-        match &self.0 {
-            SmallIntType::Inline(i) => a_sign = i.signum() as i8,
-            SmallIntType::Heap((_, s)) => a_sign = s.signum() as i8,
-        }
-
-        let b_sign;
-        match &other.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) => Some(Ordering::Greater),
-
-            x if (x.0 < 0 && x.1 >= 0) => Some(Ordering::Less),
-
-            x if (x.0 >= 0 && x.1 >= 0) => SmallUint::from_smallint_unsigned(self.clone())
-                .partial_cmp(&SmallUint::from_smallint_unsigned(other.clone())),
-
-            x if (x.0 < 0 && x.1 < 0) => SmallUint::from_smallint_unsigned(other.clone())
-                .partial_cmp(&SmallUint::from_smallint_unsigned(self.clone())),
-
-            (_, _) => None,
-        }
+        Some(self.cmp(other))
     }
 }
 
 impl Ord for SmallInt {
     fn cmp(&self, other: &Self) -> Ordering {
-        self.partial_cmp(other).expect("This should not happen.")
+        let a_sign = match &self.0 {
+            SmallIntType::Inline(i) => i.cmp(&0),
+            SmallIntType::Heap((_, s)) => s.cmp(&0),
+        };
+        let b_sign = match &other.0 {
+            SmallIntType::Inline(j) => j.cmp(&0),
+            SmallIntType::Heap((_, t)) => t.cmp(&0),
+        };
+        match a_sign.cmp(&b_sign) {
+            Ordering::Equal => match a_sign {
+                Ordering::Less => other.unsigned_abs().cmp(&self.unsigned_abs()),
+                Ordering::Equal => Ordering::Equal,
+                Ordering::Greater => self.unsigned_abs().cmp(&other.unsigned_abs()),
+            },
+            o => o,
+        }
     }
 }

src/pretty.rs

@@ -1,19 +1,151 @@
 use crate::SmallInt;
 use crate::SmallUint;
 
+use crate::smallint::{SmallIntType, SmallUintType};
+
 #[cfg(feature = "num-bigint")]
 use num_bigint::{BigInt, BigUint};
 
-#[cfg(feature = "num-bigint")]
 impl core::fmt::Debug for SmallInt {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", BigInt::from(self))
+        match self.0 {
+            SmallIntType::Inline(i) => {
+                write!(f, "{}", i)?;
+            }
+            SmallIntType::Heap((_r, _s)) => {
+                #[cfg(feature = "num-bigint")]
+                write!(f, "{}", BigInt::from(self))?;
+
+                #[cfg(not(feature = "num-bigint"))]
+                todo!();
+            }
+        }
+        Ok(())
     }
 }
 
-#[cfg(feature = "num-bigint")]
 impl core::fmt::Debug for SmallUint {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", BigUint::from(self))
+        match self.0 {
+            SmallUintType::Inline(i) => {
+                write!(f, "{}", i)?;
+            }
+            SmallUintType::Heap((_r, _s)) => {
+                #[cfg(feature = "num-bigint")]
+                write!(f, "{}", BigUint::from(self))?;
+
+                #[cfg(not(feature = "num-bigint"))]
+                todo!();
+            }
+        }
+        Ok(())
+    }
+}
+
+impl core::fmt::Display for SmallInt {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+impl core::fmt::Display for SmallUint {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+impl core::fmt::UpperHex for SmallUint {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self.0 {
+            SmallUintType::Inline(i) => write!(f, "0x{:X}", i),
+            SmallUintType::Heap((r, s)) => {
+                let slice = unsafe { core::slice::from_raw_parts(r, s) };
+                let mut iter = slice.iter().rev();
+                if let Some(i) = iter.next() {
+                    write!(f, "0x{:X}", i)?;
+                }
+                for i in iter {
+                    write!(f, "{:08X}", i)?;
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+impl core::fmt::LowerHex for SmallUint {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self.0 {
+            SmallUintType::Inline(i) => write!(f, "0x{:x}", i),
+            SmallUintType::Heap((r, s)) => {
+                let slice = unsafe { core::slice::from_raw_parts(r, s) };
+                let mut iter = slice.iter().rev();
+                if let Some(i) = iter.next() {
+                    write!(f, "0x{:x}", i)?;
+                }
+                for i in iter {
+                    write!(f, "{:08x}", i)?;
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+impl core::fmt::UpperHex for SmallInt {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self.0 {
+            SmallIntType::Inline(i) => match i {
+                x if x >= 0 => write!(f, "0x{:X}", i),
+                x if x < 0 => write!(f, "-0x{:X}", -i),
+                _ => panic!("This should not happen."),
+            },
+            SmallIntType::Heap((r, s)) => {
+                let sign = match s.signum() {
+                    x if x >= 0 => "",
+                    x if x < 0 => "-",
+                    _ => panic!("This should not happen."),
+                };
+
+                let slice = unsafe { core::slice::from_raw_parts(r, s.unsigned_abs()) };
+                let mut iter = slice.iter().rev();
+                if let Some(i) = iter.next() {
+                    write!(f, "{}0x{:X}", sign, i)?;
+                }
+                for i in iter {
+                    write!(f, "{:08X}", i)?;
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+impl core::fmt::LowerHex for SmallInt {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self.0 {
+            SmallIntType::Inline(i) => match i {
+                x if x >= 0 => write!(f, "0x{:x}", i),
+                x if x < 0 => write!(f, "-0x{:x}", -i),
+                _ => panic!("This should not happen."),
+            },
+            SmallIntType::Heap((r, s)) => {
+                let sign = match s.signum() {
+                    x if x >= 0 => "",
+                    x if x < 0 => "-",
+                    _ => panic!("This should not happen."),
+                };
+
+                let slice = unsafe { core::slice::from_raw_parts(r, s.unsigned_abs()) };
+                let mut iter = slice.iter().rev();
+                if let Some(i) = iter.next() {
+                    write!(f, "{}0x{:x}", sign, i)?;
+                }
+                for i in iter {
+                    write!(f, "{:08x}", i)?;
+                }
+                Ok(())
+            }
+        }
     }
 }

src/smallint.rs

@@ -1,3 +1,4 @@
+use core::hash::Hash;
 use core::mem::ManuallyDrop;
 
 /// An integer-like type that will store small integers up to `i128` inline. Larger integers are
@@ -21,7 +22,7 @@ pub enum SmallUintType {
 impl Drop for SmallInt {
     fn drop(&mut self) {
         if let Self(SmallIntType::Heap((r, s))) = self {
-            let size = usize::try_from(s.abs()).unwrap();
+            let size = s.unsigned_abs();
             let slice = unsafe { core::slice::from_raw_parts_mut(*r, size) };
             unsafe { std::mem::drop(Box::from_raw(slice)) }
         }
@@ -57,7 +58,7 @@ impl Clone for SmallInt {
         match self.0 {
             SmallIntType::Inline(i) => Self(SmallIntType::Inline(i)),
             SmallIntType::Heap((r, s)) => {
-                let size = usize::try_from(s.abs()).unwrap();
+                let size = s.unsigned_abs();
                 let slice = unsafe { core::slice::from_raw_parts(r, size) };
                 let mut ret = vec![0; size];
                 ret.clone_from_slice(slice);
@@ -67,3 +68,28 @@ impl Clone for SmallInt {
         }
     }
 }
+
+impl Hash for SmallUint {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        match self.0 {
+            SmallUintType::Inline(i) => i.hash(state),
+            SmallUintType::Heap((r, s)) => {
+                let slice = unsafe { core::slice::from_raw_parts(r, s) };
+                slice.hash(state);
+            }
+        }
+    }
+}
+
+impl Hash for SmallInt {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        match self.0 {
+            SmallIntType::Inline(i) => i.hash(state),
+            SmallIntType::Heap((r, s)) => {
+                let size = s.unsigned_abs();
+                let slice = unsafe { core::slice::from_raw_parts(r, size) };
+                slice.hash(state);
+            }
+        }
+    }
+}

src/tests.rs

@@ -2,6 +2,7 @@
 
 use crate::SmallInt;
 use crate::SmallUint;
+use core::fmt::Debug;
 
 #[cfg(feature = "num-bigint")]
 use num_bigint::{BigInt, BigUint, Sign};
@@ -32,305 +33,236 @@ conversion_tests!(i64, test_i64);
 conversion_tests!(u128, test_u128);
 conversion_tests!(i128, test_i128);
 
+#[cfg(feature = "num-bigint")]
+fn run_tests_u_inner(test: impl Fn(BigUint)) {
+    for i in 0u8..=7 {
+        test(BigUint::from(i));
+    }
+    for shift_scale in 1..=16 {
+        for shift_offset in -2..=2 {
+            let shift: i16 = (shift_scale * 32) + shift_offset;
+            test(BigUint::from(1u8) << shift);
+            for offset in 1u8..=7 {
+                test((BigUint::from(1u8) << shift) + BigUint::from(offset));
+                test((BigUint::from(1u8) << shift) - BigUint::from(offset));
+            }
+        }
+    }
+    test(BigUint::new(vec![3, 9, 8, 3, 1]));
+    test(BigUint::new(vec![5, 4, 9, 3, 1, 81]));
+}
+
+#[allow(dead_code)]
+#[cfg(feature = "num-bigint")]
+fn run_tests_u_1<T: Eq + Debug>(small: impl Fn(SmallUint) -> T, big: impl Fn(&BigUint) -> T) {
+    run_tests_u_inner(|i| {
+        let small_result = small(SmallUint::from(&i));
+        let big_result = big(&i);
+        assert_eq!(
+            small_result,
+            big_result,
+            "{:#x}", i
+        );
+    });
+}
+
+#[cfg(feature = "num-bigint")]
+fn run_tests_u_2<T: Eq + Debug>(
+    small: impl Fn(SmallUint, SmallUint) -> T,
+    big: impl Fn(&BigUint, &BigUint) -> T
+) {
+    run_tests_u_inner(|i| run_tests_u_inner(|k| {
+        let small_result = small(SmallUint::from(&i), SmallUint::from(&k));
+        let big_result = big(&i, &k);
+        assert_eq!(
+            small_result,
+            big_result,
+            "{:#x} {:#x}", i, k
+        );
+    }));
+}
+
+#[cfg(feature = "num-bigint")]
+fn run_tests_i_inner(test: impl Fn(BigInt)) {
+    run_tests_u_inner(|value| {
+        test(BigInt::from_biguint(Sign::Plus, value.clone()));
+        test(BigInt::from_biguint(Sign::Minus, value));
+    });
+}
+
+#[cfg(feature = "num-bigint")]
+fn run_tests_i_1<T: Eq + Debug>(small: impl Fn(SmallInt) -> T, big: impl Fn(&BigInt) -> T) {
+    run_tests_i_inner(|i| {
+        let small_result = small(SmallInt::from(&i));
+        let big_result = big(&i);
+        assert_eq!(
+            small_result,
+            big_result,
+            "{:#x}", i
+        );
+    });
+}
+
+#[cfg(feature = "num-bigint")]
+fn run_tests_i_2<T: Eq + Debug>(
+    small: impl Fn(SmallInt, SmallInt) -> T,
+    big: impl Fn(&BigInt, &BigInt) -> T
+) {
+    run_tests_i_inner(|i| run_tests_i_inner(|k| {
+        let small_result = small(SmallInt::from(&i), SmallInt::from(&k));
+        let big_result = big(&i, &k);
+        assert_eq!(
+            small_result,
+            big_result,
+            "{:#x} {:#x}", i, k
+        );
+    }));
+}
+
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_convert_biguint() {
+    run_tests_u_1(|i| BigUint::from(&i), |i| i.clone());
+    run_tests_u_1(|i| i, |i| SmallUint::from(i));
+}
+
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_convert_bigint() {
+    run_tests_i_1(|i| BigInt::from(&i), |i| i.clone());
+    run_tests_i_1(|i| i, |i| SmallInt::from(i));
+}
+
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_cmp_u() {
-    let i = SmallUint::from(30u32);
-    let k = SmallUint::from(50u32);
-    assert!(i < k);
-
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    assert!(i < k);
-
-    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    assert!(i < k);
+    run_tests_u_2(
+        |i, k| i.partial_cmp(&k),
+        |i, k| i.partial_cmp(&k),
+    );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_cmp_i() {
-    let i = SmallInt::from(30u32);
-    let k = SmallInt::from(50u32);
-    assert!(i < k);
-
-    let i = SmallInt::from(u128::MAX);
-    let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
-    assert!(i < k);
-
-    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]));
-    assert!(i < k);
-
-    let i = SmallInt::from(30u32);
-    let k = -SmallInt::from(50u32);
-    assert!(k < i);
-
-    let i = SmallInt::from(u128::MAX);
-    let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
-    assert!(k < i);
-
-    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]));
-    assert!(k < i);
+    run_tests_i_2(
+        |i, k| i.partial_cmp(&k),
+        |i, k| i.partial_cmp(&k),
+    );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_add_u() {
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(u128::MAX);
-    let q = i + k;
-    assert_eq!(BigUint::from(&q), BigUint::from(u128::MAX) + u128::MAX);
-
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let q = i + k;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) + u128::MAX
-    );
-
-    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let q = i + k;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![3, 9, 8, 3, 1]) + BigUint::new(vec![5, 4, 9, 3, 1, 81])
+    run_tests_u_2(
+        |i, k| BigUint::from(&(i + k)),
+        |i, k| i + k,
     );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_add_i() {
-    let i = SmallInt::from(u128::MAX);
-    let k = -SmallInt::from(u128::MAX);
-    let q = i + k;
-    assert_eq!(BigInt::from(&q), BigInt::from(0));
-
-    let i = SmallInt::from(u128::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),
-        u128::MAX - 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 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])
-            - BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1])
+    run_tests_i_2(
+        |i, k| BigInt::from(&(i + k)),
+        |i, k| i + k,
     );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_mul_u() {
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(u128::MAX);
-    let q = i * k;
-    assert_eq!(BigUint::from(&q), BigUint::from(u128::MAX) * u128::MAX);
-
-    let i = SmallUint::from(u32::MAX);
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let q = i * k;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) * u32::MAX
-    );
-
-    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let q = i * k;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![3, 9, 8, 3, 1]) * BigUint::new(vec![5, 4, 9, 3, 1, 81])
+    run_tests_u_2(
+        |i, k| BigUint::from(&(i * k)),
+        |i, k| i * k,
     );
 }
 
 #[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])
+    run_tests_i_2(
+        |i, k| BigInt::from(&(i * k)),
+        |i, k| i * k,
     );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_sub_u() {
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(u128::MAX);
-    let q = i - k;
-    assert_eq!(BigUint::from(&q), BigUint::from(u128::MAX) - u128::MAX);
-
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(u128::MAX);
-    let q = k - i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) - u128::MAX
-    );
-
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
-    let q = k - i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) - BigUint::new(vec![3, 9, 8, 3, 1])
+    run_tests_u_2(
+        |i, k| (i >= k).then(|| BigUint::from(&(i - k))),
+        |i, k| (i >= k).then(|| i - k),
     );
 }
 
 #[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]))
+    run_tests_i_2(
+        |i, k| BigInt::from(&(i - k)),
+        |i, k| i - k,
     );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_and_u() {
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(u128::MAX);
-    let q = i & k;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::from(u128::MAX) & BigUint::from(u128::MAX)
+    run_tests_u_2(
+        |i, k| BigUint::from(&(i & k)),
+        |i, k| i & k,
     );
+}
 
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(u128::MAX);
-    let q = k & i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3]) & BigUint::from(u128::MAX)
-    );
-
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
-    let q = k & i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) & BigUint::new(vec![3, 9, 8, 3, 1])
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_op_and_i() {
+    run_tests_i_2(
+        |i, k| BigInt::from(&(i & k)),
+        |i, k| i & k,
     );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_or_u() {
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(u128::MAX);
-    let q = i | k;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::from(u128::MAX) | BigUint::from(u128::MAX)
-    );
-
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(u128::MAX);
-    let q = k | i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) | BigUint::from(u128::MAX)
-    );
-
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
-    let q = k | i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) | BigUint::new(vec![3, 9, 8, 3, 1])
+    run_tests_u_2(
+        |i, k| BigUint::from(&(i | k)),
+        |i, k| i | k,
     );
 }
 
+// #[test]
+// #[cfg(feature = "num-bigint")]
+// fn test_op_or_i() {
+//     run_tests_i_2(
+//         |i, k| BigInt::from(&(i | k)),
+//         |i, k| i | k,
+//     );
+// }
+
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_xor_u() {
-    let i = SmallUint::from(u128::MAX);
-    let k = SmallUint::from(u128::MAX);
-    let q = i ^ k;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::from(u128::MAX) ^ BigUint::from(u128::MAX)
-    );
-
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(u128::MAX);
-    let q = k ^ i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) ^ BigUint::from(u128::MAX)
-    );
-
-    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
-    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
-    let q = k ^ i;
-    assert_eq!(
-        BigUint::from(&q),
-        BigUint::new(vec![5, 4, 9, 3, 1, 81]) ^ BigUint::new(vec![3, 9, 8, 3, 1])
+    run_tests_u_2(
+        |i, k| BigUint::from(&(i ^ k)),
+        |i, k| i ^ k,
     );
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_op_neg() {
-    let i = SmallInt::from(u128::MAX);
-    let q = -i;
-    assert_eq!(BigInt::from(&q), -BigInt::from(u128::MAX));
-
-    let i = SmallInt::from(i64::MIN);
-    let q = -i;
-    assert_eq!(BigInt::from(&q), -BigInt::from(i64::MIN));
+    run_tests_i_1(|i| BigInt::from(&-i), |i| -i.clone());
 }
 
 #[test]
 #[cfg(feature = "num-bigint")]
 fn test_conversion_sign_drop() {
-    let si = SmallInt::from(i128::MIN + 1);
-    let i = SmallUint::from_smallint_unsigned(si);
-    assert_eq!(BigUint::from(&i), BigUint::from(-(i128::MIN + 1) as u128))
+    run_tests_i_1(
+        |i| BigUint::from(&SmallInt::unsigned_abs(&i)),
+        |i| i.magnitude().clone()
+    );
 }
 
 #[test]