Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

29 files changed, 10868 insertions, 0 deletions

diff --git a/vendor/memchr/src/arch/aarch64/memchr.rs b/vendor/memchr/src/arch/aarch64/memchr.rs
new file mode 100644
index 0000000..e0053b2
--- /dev/null
+++ b/vendor/memchr/src/arch/aarch64/memchr.rs
@@ -0,0 +1,137 @@
+/*!
+Wrapper routines for `memchr` and friends.
+
+These routines choose the best implementation at compile time. (This is
+different from `x86_64` because it is expected that `neon` is almost always
+available for `aarch64` targets.)
+*/
+
+macro_rules! defraw {
+    ($ty:ident, $find:ident, $start:ident, $end:ident, $($needles:ident),+) => {{
+        #[cfg(target_feature = "neon")]
+        {
+            use crate::arch::aarch64::neon::memchr::$ty;
+
+            debug!("chose neon for {}", stringify!($ty));
+            debug_assert!($ty::is_available());
+            // SAFETY: We know that wasm memchr is always available whenever
+            // code is compiled for `aarch64` with the `neon` target feature
+            // enabled.
+            $ty::new_unchecked($($needles),+).$find($start, $end)
+        }
+        #[cfg(not(target_feature = "neon"))]
+        {
+            use crate::arch::all::memchr::$ty;
+
+            debug!(
+                "no neon feature available, using fallback for {}",
+                stringify!($ty),
+            );
+            $ty::new($($needles),+).$find($start, $end)
+        }
+    }}
+}
+
+/// memchr, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::find_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memchr_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(One, find_raw, start, end, n1)
+}
+
+/// memrchr, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::rfind_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memrchr_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(One, rfind_raw, start, end, n1)
+}
+
+/// memchr2, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Two::find_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memchr2_raw(
+    n1: u8,
+    n2: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Two, find_raw, start, end, n1, n2)
+}
+
+/// memrchr2, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Two::rfind_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memrchr2_raw(
+    n1: u8,
+    n2: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Two, rfind_raw, start, end, n1, n2)
+}
+
+/// memchr3, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Three::find_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memchr3_raw(
+    n1: u8,
+    n2: u8,
+    n3: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Three, find_raw, start, end, n1, n2, n3)
+}
+
+/// memrchr3, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Three::rfind_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memrchr3_raw(
+    n1: u8,
+    n2: u8,
+    n3: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Three, rfind_raw, start, end, n1, n2, n3)
+}
+
+/// Count all matching bytes, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::count_raw`.
+#[inline(always)]
+pub(crate) unsafe fn count_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> usize {
+    defraw!(One, count_raw, start, end, n1)
+}
diff --git a/vendor/memchr/src/arch/aarch64/mod.rs b/vendor/memchr/src/arch/aarch64/mod.rs
new file mode 100644
index 0000000..7b32912
--- /dev/null
+++ b/vendor/memchr/src/arch/aarch64/mod.rs
@@ -0,0 +1,7 @@
+/*!
+Vector algorithms for the `aarch64` target.
+*/
+
+pub mod neon;
+
+pub(crate) mod memchr;
diff --git a/vendor/memchr/src/arch/aarch64/neon/memchr.rs b/vendor/memchr/src/arch/aarch64/neon/memchr.rs
new file mode 100644
index 0000000..5fcc762
--- /dev/null
+++ b/vendor/memchr/src/arch/aarch64/neon/memchr.rs
@@ -0,0 +1,1031 @@
+/*!
+This module defines 128-bit vector implementations of `memchr` and friends.
+
+The main types in this module are [`One`], [`Two`] and [`Three`]. They are for
+searching for one, two or three distinct bytes, respectively, in a haystack.
+Each type also has corresponding double ended iterators. These searchers are
+typically much faster than scalar routines accomplishing the same task.
+
+The `One` searcher also provides a [`One::count`] routine for efficiently
+counting the number of times a single byte occurs in a haystack. This is
+useful, for example, for counting the number of lines in a haystack. This
+routine exists because it is usually faster, especially with a high match
+count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its
+`Iterator::count` implementation to use this routine.)
+
+Only one, two and three bytes are supported because three bytes is about
+the point where one sees diminishing returns. Beyond this point and it's
+probably (but not necessarily) better to just use a simple `[bool; 256]` array
+or similar. However, it depends mightily on the specific work-load and the
+expected match frequency.
+*/
+
+use core::arch::aarch64::uint8x16_t;
+
+use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector};
+
+/// Finds all occurrences of a single byte in a haystack.
+#[derive(Clone, Copy, Debug)]
+pub struct One(generic::One<uint8x16_t>);
+
+impl One {
+    /// Create a new searcher that finds occurrences of the needle byte given.
+    ///
+    /// This particular searcher is specialized to use neon vector instructions
+    /// that typically make it quite fast.
+    ///
+    /// If neon is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle: u8) -> Option<One> {
+        if One::is_available() {
+            // SAFETY: we check that neon is available above.
+            unsafe { Some(One::new_unchecked(needle)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to neon vectors and routines without
+    /// checking that neon is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `neon` instructions
+    /// in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to neon
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "neon")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle: u8) -> One {
+        One(generic::One::new(needle))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`One::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `One::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "neon")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "neon"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Counts all occurrences of this byte in the given haystack.
+    #[inline]
+    pub fn count(&self, haystack: &[u8]) -> usize {
+        // SAFETY: All of our pointers are derived directly from a borrowed
+        // slice, which is guaranteed to be valid.
+        unsafe {
+            let start = haystack.as_ptr();
+            let end = start.add(haystack.len());
+            self.count_raw(start, end)
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < uint8x16_t::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'neon' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < uint8x16_t::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'neon' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Like `count`, but accepts and returns raw pointers.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize {
+        if start >= end {
+            return 0;
+        }
+        if end.distance(start) < uint8x16_t::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::count_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'neon' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.count_raw_impl(start, end)
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a neon vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a neon vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Execute a count using neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::count_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a neon vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn count_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> usize {
+        self.0.count_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> {
+        OneIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of a single byte in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`One::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`One`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct OneIter<'a, 'h> {
+    searcher: &'a One,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for OneIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn count(self) -> usize {
+        self.it.count(|s, e| {
+            // SAFETY: We rely on our generic iterator to return valid start
+            // and end pointers.
+            unsafe { self.searcher.count_raw(s, e) }
+        })
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {}
+
+/// Finds all occurrences of two bytes in a haystack.
+///
+/// That is, this reports matches of one of two possible bytes. For example,
+/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`,
+/// `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Two(generic::Two<uint8x16_t>);
+
+impl Two {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use neon vector instructions
+    /// that typically make it quite fast.
+    ///
+    /// If neon is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8) -> Option<Two> {
+        if Two::is_available() {
+            // SAFETY: we check that neon is available above.
+            unsafe { Some(Two::new_unchecked(needle1, needle2)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to neon vectors and routines without
+    /// checking that neon is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `neon` instructions
+    /// in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to neon
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "neon")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two {
+        Two(generic::Two::new(needle1, needle2))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Two::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Two::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "neon")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "neon"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < uint8x16_t::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1() || b == self.0.needle2()
+            });
+        }
+        // SAFETY: Building a `Two` means it's safe to call 'neon' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < uint8x16_t::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1() || b == self.0.needle2()
+            });
+        }
+        // SAFETY: Building a `Two` means it's safe to call 'neon' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a neon vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a neon vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle bytes in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> {
+        TwoIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of two possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Two::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Two`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct TwoIter<'a, 'h> {
+    searcher: &'a Two,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for TwoIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {}
+
+/// Finds all occurrences of three bytes in a haystack.
+///
+/// That is, this reports matches of one of three possible bytes. For example,
+/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets
+/// `0`, `2`, `3`, `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Three(generic::Three<uint8x16_t>);
+
+impl Three {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use neon vector instructions
+    /// that typically make it quite fast.
+    ///
+    /// If neon is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> {
+        if Three::is_available() {
+            // SAFETY: we check that neon is available above.
+            unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to neon vectors and routines without
+    /// checking that neon is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `neon` instructions
+    /// in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to neon
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "neon")]
+    #[inline]
+    pub unsafe fn new_unchecked(
+        needle1: u8,
+        needle2: u8,
+        needle3: u8,
+    ) -> Three {
+        Three(generic::Three::new(needle1, needle2, needle3))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Three::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Three::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "neon")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "neon"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < uint8x16_t::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+                    || b == self.0.needle2()
+                    || b == self.0.needle3()
+            });
+        }
+        // SAFETY: Building a `Three` means it's safe to call 'neon' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < uint8x16_t::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+                    || b == self.0.needle2()
+                    || b == self.0.needle3()
+            });
+        }
+        // SAFETY: Building a `Three` means it's safe to call 'neon' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a neon vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a neon vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> {
+        ThreeIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of three possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Three::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Three`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct ThreeIter<'a, 'h> {
+    searcher: &'a Three,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for ThreeIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    define_memchr_quickcheck!(super);
+
+    #[test]
+    fn forward_one() {
+        crate::tests::memchr::Runner::new(1).forward_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_one() {
+        crate::tests::memchr::Runner::new(1).reverse_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn count_one() {
+        crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| {
+            Some(One::new(needles[0])?.iter(haystack).count())
+        })
+    }
+
+    #[test]
+    fn forward_two() {
+        crate::tests::memchr::Runner::new(2).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_two() {
+        crate::tests::memchr::Runner::new(2).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn forward_three() {
+        crate::tests::memchr::Runner::new(3).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_three() {
+        crate::tests::memchr::Runner::new(3).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+}
diff --git a/vendor/memchr/src/arch/aarch64/neon/mod.rs b/vendor/memchr/src/arch/aarch64/neon/mod.rs
new file mode 100644
index 0000000..ccf9cf8
--- /dev/null
+++ b/vendor/memchr/src/arch/aarch64/neon/mod.rs
@@ -0,0 +1,6 @@
+/*!
+Algorithms for the `aarch64` target using 128-bit vectors via NEON.
+*/
+
+pub mod memchr;
+pub mod packedpair;
diff --git a/vendor/memchr/src/arch/aarch64/neon/packedpair.rs b/vendor/memchr/src/arch/aarch64/neon/packedpair.rs
new file mode 100644
index 0000000..6884882
--- /dev/null
+++ b/vendor/memchr/src/arch/aarch64/neon/packedpair.rs
@@ -0,0 +1,236 @@
+/*!
+A 128-bit vector implementation of the "packed pair" SIMD algorithm.
+
+The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main
+difference is that it (by default) uses a background distribution of byte
+frequencies to heuristically select the pair of bytes to search for.
+
+[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last
+*/
+
+use core::arch::aarch64::uint8x16_t;
+
+use crate::arch::{all::packedpair::Pair, generic::packedpair};
+
+/// A "packed pair" finder that uses 128-bit vector operations.
+///
+/// This finder picks two bytes that it believes have high predictive power
+/// for indicating an overall match of a needle. Depending on whether
+/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets
+/// where the needle matches or could match. In the prefilter case, candidates
+/// are reported whenever the [`Pair`] of bytes given matches.
+#[derive(Clone, Copy, Debug)]
+pub struct Finder(packedpair::Finder<uint8x16_t>);
+
+/// A "packed pair" finder that uses 128-bit vector operations.
+///
+/// This finder picks two bytes that it believes have high predictive power
+/// for indicating an overall match of a needle. Depending on whether
+/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets
+/// where the needle matches or could match. In the prefilter case, candidates
+/// are reported whenever the [`Pair`] of bytes given matches.
+impl Finder {
+    /// Create a new pair searcher. The searcher returned can either report
+    /// exact matches of `needle` or act as a prefilter and report candidate
+    /// positions of `needle`.
+    ///
+    /// If neon is unavailable in the current environment or if a [`Pair`]
+    /// could not be constructed from the needle given, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Option<Finder> {
+        Finder::with_pair(needle, Pair::new(needle)?)
+    }
+
+    /// Create a new "packed pair" finder using the pair of bytes given.
+    ///
+    /// This constructor permits callers to control precisely which pair of
+    /// bytes is used as a predicate.
+    ///
+    /// If neon is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> {
+        if Finder::is_available() {
+            // SAFETY: we check that sse2 is available above. We are also
+            // guaranteed to have needle.len() > 1 because we have a valid
+            // Pair.
+            unsafe { Some(Finder::with_pair_impl(needle, pair)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new `Finder` specific to neon vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as the safety for `packedpair::Finder::new`, and callers must also
+    /// ensure that neon is available.
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder {
+        let finder = packedpair::Finder::<uint8x16_t>::new(needle, pair);
+        Finder(finder)
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Finder::with_pair`] will
+    /// return a `Some` value. Similarly, when it is false, it is guaranteed
+    /// that `Finder::with_pair` will return a `None` value. Notice that this
+    /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely,
+    /// even when `Finder::is_available` is true, it is not guaranteed that a
+    /// valid [`Pair`] can be found from the needle given.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "neon")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "neon"))]
+        {
+            false
+        }
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        // SAFETY: Building a `Finder` means it's safe to call 'neon' routines.
+        unsafe { self.find_impl(haystack, needle) }
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: Building a `Finder` means it's safe to call 'neon' routines.
+        unsafe { self.find_prefilter_impl(haystack) }
+    }
+
+    /// Execute a search using neon vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn find_impl(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        self.0.find(haystack, needle)
+    }
+
+    /// Execute a prefilter search using neon vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `neon` routines.)
+    #[target_feature(enable = "neon")]
+    #[inline]
+    unsafe fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> {
+        self.0.find_prefilter(haystack)
+    }
+
+    /// Returns the pair of offsets (into the needle) used to check as a
+    /// predicate before confirming whether a needle exists at a particular
+    /// position.
+    #[inline]
+    pub fn pair(&self) -> &Pair {
+        self.0.pair()
+    }
+
+    /// Returns the minimum haystack length that this `Finder` can search.
+    ///
+    /// Using a haystack with length smaller than this in a search will result
+    /// in a panic. The reason for this restriction is that this finder is
+    /// meant to be a low-level component that is part of a larger substring
+    /// strategy. In that sense, it avoids trying to handle all cases and
+    /// instead only handles the cases that it can handle very well.
+    #[inline]
+    pub fn min_haystack_len(&self) -> usize {
+        self.0.min_haystack_len()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> {
+        let f = Finder::new(needle)?;
+        if haystack.len() < f.min_haystack_len() {
+            return None;
+        }
+        Some(f.find(haystack, needle))
+    }
+
+    define_substring_forward_quickcheck!(find);
+
+    #[test]
+    fn forward_substring() {
+        crate::tests::substring::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find(haystack, needle))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair_prefilter() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find_prefilter(haystack))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+}
diff --git a/vendor/memchr/src/arch/all/memchr.rs b/vendor/memchr/src/arch/all/memchr.rs
new file mode 100644
index 0000000..435b1be
--- /dev/null
+++ b/vendor/memchr/src/arch/all/memchr.rs
@@ -0,0 +1,996 @@
+/*!
+Provides architecture independent implementations of `memchr` and friends.
+
+The main types in this module are [`One`], [`Two`] and [`Three`]. They are for
+searching for one, two or three distinct bytes, respectively, in a haystack.
+Each type also has corresponding double ended iterators. These searchers
+are typically slower than hand-coded vector routines accomplishing the same
+task, but are also typically faster than naive scalar code. These routines
+effectively work by treating a `usize` as a vector of 8-bit lanes, and thus
+achieves some level of data parallelism even without explicit vector support.
+
+The `One` searcher also provides a [`One::count`] routine for efficiently
+counting the number of times a single byte occurs in a haystack. This is
+useful, for example, for counting the number of lines in a haystack. This
+routine exists because it is usually faster, especially with a high match
+count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its
+`Iterator::count` implementation to use this routine.)
+
+Only one, two and three bytes are supported because three bytes is about
+the point where one sees diminishing returns. Beyond this point and it's
+probably (but not necessarily) better to just use a simple `[bool; 256]` array
+or similar. However, it depends mightily on the specific work-load and the
+expected match frequency.
+*/
+
+use crate::{arch::generic::memchr as generic, ext::Pointer};
+
+/// The number of bytes in a single `usize` value.
+const USIZE_BYTES: usize = (usize::BITS / 8) as usize;
+/// The bits that must be zero for a `*const usize` to be properly aligned.
+const USIZE_ALIGN: usize = USIZE_BYTES - 1;
+
+/// Finds all occurrences of a single byte in a haystack.
+#[derive(Clone, Copy, Debug)]
+pub struct One {
+    s1: u8,
+    v1: usize,
+}
+
+impl One {
+    /// The number of bytes we examine per each iteration of our search loop.
+    const LOOP_BYTES: usize = 2 * USIZE_BYTES;
+
+    /// Create a new searcher that finds occurrences of the byte given.
+    #[inline]
+    pub fn new(needle: u8) -> One {
+        One { s1: needle, v1: splat(needle) }
+    }
+
+    /// A test-only routine so that we can bundle a bunch of quickcheck
+    /// properties into a single macro. Basically, this provides a constructor
+    /// that makes it identical to most other memchr implementations, which
+    /// have fallible constructors.
+    #[cfg(test)]
+    pub(crate) fn try_new(needle: u8) -> Option<One> {
+        Some(One::new(needle))
+    }
+
+    /// Return the first occurrence of the needle in the given haystack. If no
+    /// such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value for a non-empty haystack is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of the needle in the given haystack. If no
+    /// such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value for a non-empty haystack is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Counts all occurrences of this byte in the given haystack.
+    #[inline]
+    pub fn count(&self, haystack: &[u8]) -> usize {
+        // SAFETY: All of our pointers are derived directly from a borrowed
+        // slice, which is guaranteed to be valid.
+        unsafe {
+            let start = haystack.as_ptr();
+            let end = start.add(haystack.len());
+            self.count_raw(start, end)
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let confirm = |b| self.confirm(b);
+        let len = end.distance(start);
+        if len < USIZE_BYTES {
+            return generic::fwd_byte_by_byte(start, end, confirm);
+        }
+
+        // The start of the search may not be aligned to `*const usize`,
+        // so we do an unaligned load here.
+        let chunk = start.cast::<usize>().read_unaligned();
+        if self.has_needle(chunk) {
+            return generic::fwd_byte_by_byte(start, end, confirm);
+        }
+
+        // And now we start our search at a guaranteed aligned position.
+        // The first iteration of the loop below will overlap with the the
+        // unaligned chunk above in cases where the search starts at an
+        // unaligned offset, but that's okay as we're only here if that
+        // above didn't find a match.
+        let mut cur =
+            start.add(USIZE_BYTES - (start.as_usize() & USIZE_ALIGN));
+        debug_assert!(cur > start);
+        if len <= One::LOOP_BYTES {
+            return generic::fwd_byte_by_byte(cur, end, confirm);
+        }
+        debug_assert!(end.sub(One::LOOP_BYTES) >= start);
+        while cur <= end.sub(One::LOOP_BYTES) {
+            debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES);
+
+            let a = cur.cast::<usize>().read();
+            let b = cur.add(USIZE_BYTES).cast::<usize>().read();
+            if self.has_needle(a) || self.has_needle(b) {
+                break;
+            }
+            cur = cur.add(One::LOOP_BYTES);
+        }
+        generic::fwd_byte_by_byte(cur, end, confirm)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let confirm = |b| self.confirm(b);
+        let len = end.distance(start);
+        if len < USIZE_BYTES {
+            return generic::rev_byte_by_byte(start, end, confirm);
+        }
+
+        let chunk = end.sub(USIZE_BYTES).cast::<usize>().read_unaligned();
+        if self.has_needle(chunk) {
+            return generic::rev_byte_by_byte(start, end, confirm);
+        }
+
+        let mut cur = end.sub(end.as_usize() & USIZE_ALIGN);
+        debug_assert!(start <= cur && cur <= end);
+        if len <= One::LOOP_BYTES {
+            return generic::rev_byte_by_byte(start, cur, confirm);
+        }
+        while cur >= start.add(One::LOOP_BYTES) {
+            debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES);
+
+            let a = cur.sub(2 * USIZE_BYTES).cast::<usize>().read();
+            let b = cur.sub(1 * USIZE_BYTES).cast::<usize>().read();
+            if self.has_needle(a) || self.has_needle(b) {
+                break;
+            }
+            cur = cur.sub(One::LOOP_BYTES);
+        }
+        generic::rev_byte_by_byte(start, cur, confirm)
+    }
+
+    /// Counts all occurrences of this byte in the given haystack represented
+    /// by raw pointers.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `0` will always be returned.
+    #[inline]
+    pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize {
+        if start >= end {
+            return 0;
+        }
+        // Sadly I couldn't get the SWAR approach to work here, so we just do
+        // one byte at a time for now. PRs to improve this are welcome.
+        let mut ptr = start;
+        let mut count = 0;
+        while ptr < end {
+            count += (ptr.read() == self.s1) as usize;
+            ptr = ptr.offset(1);
+        }
+        count
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> {
+        OneIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+
+    #[inline(always)]
+    fn has_needle(&self, chunk: usize) -> bool {
+        has_zero_byte(self.v1 ^ chunk)
+    }
+
+    #[inline(always)]
+    fn confirm(&self, haystack_byte: u8) -> bool {
+        self.s1 == haystack_byte
+    }
+}
+
+/// An iterator over all occurrences of a single byte in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`One::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`One`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct OneIter<'a, 'h> {
+    /// The underlying memchr searcher.
+    searcher: &'a One,
+    /// Generic iterator implementation.
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for OneIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn count(self) -> usize {
+        self.it.count(|s, e| {
+            // SAFETY: We rely on our generic iterator to return valid start
+            // and end pointers.
+            unsafe { self.searcher.count_raw(s, e) }
+        })
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+/// Finds all occurrences of two bytes in a haystack.
+///
+/// That is, this reports matches of one of two possible bytes. For example,
+/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`,
+/// `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Two {
+    s1: u8,
+    s2: u8,
+    v1: usize,
+    v2: usize,
+}
+
+impl Two {
+    /// Create a new searcher that finds occurrences of the two needle bytes
+    /// given.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8) -> Two {
+        Two {
+            s1: needle1,
+            s2: needle2,
+            v1: splat(needle1),
+            v2: splat(needle2),
+        }
+    }
+
+    /// A test-only routine so that we can bundle a bunch of quickcheck
+    /// properties into a single macro. Basically, this provides a constructor
+    /// that makes it identical to most other memchr implementations, which
+    /// have fallible constructors.
+    #[cfg(test)]
+    pub(crate) fn try_new(needle1: u8, needle2: u8) -> Option<Two> {
+        Some(Two::new(needle1, needle2))
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value for a non-empty haystack is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value for a non-empty haystack is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let confirm = |b| self.confirm(b);
+        let len = end.distance(start);
+        if len < USIZE_BYTES {
+            return generic::fwd_byte_by_byte(start, end, confirm);
+        }
+
+        // The start of the search may not be aligned to `*const usize`,
+        // so we do an unaligned load here.
+        let chunk = start.cast::<usize>().read_unaligned();
+        if self.has_needle(chunk) {
+            return generic::fwd_byte_by_byte(start, end, confirm);
+        }
+
+        // And now we start our search at a guaranteed aligned position.
+        // The first iteration of the loop below will overlap with the the
+        // unaligned chunk above in cases where the search starts at an
+        // unaligned offset, but that's okay as we're only here if that
+        // above didn't find a match.
+        let mut cur =
+            start.add(USIZE_BYTES - (start.as_usize() & USIZE_ALIGN));
+        debug_assert!(cur > start);
+        debug_assert!(end.sub(USIZE_BYTES) >= start);
+        while cur <= end.sub(USIZE_BYTES) {
+            debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES);
+
+            let chunk = cur.cast::<usize>().read();
+            if self.has_needle(chunk) {
+                break;
+            }
+            cur = cur.add(USIZE_BYTES);
+        }
+        generic::fwd_byte_by_byte(cur, end, confirm)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let confirm = |b| self.confirm(b);
+        let len = end.distance(start);
+        if len < USIZE_BYTES {
+            return generic::rev_byte_by_byte(start, end, confirm);
+        }
+
+        let chunk = end.sub(USIZE_BYTES).cast::<usize>().read_unaligned();
+        if self.has_needle(chunk) {
+            return generic::rev_byte_by_byte(start, end, confirm);
+        }
+
+        let mut cur = end.sub(end.as_usize() & USIZE_ALIGN);
+        debug_assert!(start <= cur && cur <= end);
+        while cur >= start.add(USIZE_BYTES) {
+            debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES);
+
+            let chunk = cur.sub(USIZE_BYTES).cast::<usize>().read();
+            if self.has_needle(chunk) {
+                break;
+            }
+            cur = cur.sub(USIZE_BYTES);
+        }
+        generic::rev_byte_by_byte(start, cur, confirm)
+    }
+
+    /// Returns an iterator over all occurrences of one of the needle bytes in
+    /// the given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> {
+        TwoIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+
+    #[inline(always)]
+    fn has_needle(&self, chunk: usize) -> bool {
+        has_zero_byte(self.v1 ^ chunk) || has_zero_byte(self.v2 ^ chunk)
+    }
+
+    #[inline(always)]
+    fn confirm(&self, haystack_byte: u8) -> bool {
+        self.s1 == haystack_byte || self.s2 == haystack_byte
+    }
+}
+
+/// An iterator over all occurrences of two possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Two::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Two`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct TwoIter<'a, 'h> {
+    /// The underlying memchr searcher.
+    searcher: &'a Two,
+    /// Generic iterator implementation.
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for TwoIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+/// Finds all occurrences of three bytes in a haystack.
+///
+/// That is, this reports matches of one of three possible bytes. For example,
+/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets
+/// `0`, `2`, `3`, `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Three {
+    s1: u8,
+    s2: u8,
+    s3: u8,
+    v1: usize,
+    v2: usize,
+    v3: usize,
+}
+
+impl Three {
+    /// Create a new searcher that finds occurrences of the three needle bytes
+    /// given.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Three {
+        Three {
+            s1: needle1,
+            s2: needle2,
+            s3: needle3,
+            v1: splat(needle1),
+            v2: splat(needle2),
+            v3: splat(needle3),
+        }
+    }
+
+    /// A test-only routine so that we can bundle a bunch of quickcheck
+    /// properties into a single macro. Basically, this provides a constructor
+    /// that makes it identical to most other memchr implementations, which
+    /// have fallible constructors.
+    #[cfg(test)]
+    pub(crate) fn try_new(
+        needle1: u8,
+        needle2: u8,
+        needle3: u8,
+    ) -> Option<Three> {
+        Some(Three::new(needle1, needle2, needle3))
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value for a non-empty haystack is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value for a non-empty haystack is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let confirm = |b| self.confirm(b);
+        let len = end.distance(start);
+        if len < USIZE_BYTES {
+            return generic::fwd_byte_by_byte(start, end, confirm);
+        }
+
+        // The start of the search may not be aligned to `*const usize`,
+        // so we do an unaligned load here.
+        let chunk = start.cast::<usize>().read_unaligned();
+        if self.has_needle(chunk) {
+            return generic::fwd_byte_by_byte(start, end, confirm);
+        }
+
+        // And now we start our search at a guaranteed aligned position.
+        // The first iteration of the loop below will overlap with the the
+        // unaligned chunk above in cases where the search starts at an
+        // unaligned offset, but that's okay as we're only here if that
+        // above didn't find a match.
+        let mut cur =
+            start.add(USIZE_BYTES - (start.as_usize() & USIZE_ALIGN));
+        debug_assert!(cur > start);
+        debug_assert!(end.sub(USIZE_BYTES) >= start);
+        while cur <= end.sub(USIZE_BYTES) {
+            debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES);
+
+            let chunk = cur.cast::<usize>().read();
+            if self.has_needle(chunk) {
+                break;
+            }
+            cur = cur.add(USIZE_BYTES);
+        }
+        generic::fwd_byte_by_byte(cur, end, confirm)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let confirm = |b| self.confirm(b);
+        let len = end.distance(start);
+        if len < USIZE_BYTES {
+            return generic::rev_byte_by_byte(start, end, confirm);
+        }
+
+        let chunk = end.sub(USIZE_BYTES).cast::<usize>().read_unaligned();
+        if self.has_needle(chunk) {
+            return generic::rev_byte_by_byte(start, end, confirm);
+        }
+
+        let mut cur = end.sub(end.as_usize() & USIZE_ALIGN);
+        debug_assert!(start <= cur && cur <= end);
+        while cur >= start.add(USIZE_BYTES) {
+            debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES);
+
+            let chunk = cur.sub(USIZE_BYTES).cast::<usize>().read();
+            if self.has_needle(chunk) {
+                break;
+            }
+            cur = cur.sub(USIZE_BYTES);
+        }
+        generic::rev_byte_by_byte(start, cur, confirm)
+    }
+
+    /// Returns an iterator over all occurrences of one of the needle bytes in
+    /// the given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> {
+        ThreeIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+
+    #[inline(always)]
+    fn has_needle(&self, chunk: usize) -> bool {
+        has_zero_byte(self.v1 ^ chunk)
+            || has_zero_byte(self.v2 ^ chunk)
+            || has_zero_byte(self.v3 ^ chunk)
+    }
+
+    #[inline(always)]
+    fn confirm(&self, haystack_byte: u8) -> bool {
+        self.s1 == haystack_byte
+            || self.s2 == haystack_byte
+            || self.s3 == haystack_byte
+    }
+}
+
+/// An iterator over all occurrences of three possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Three::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Three`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct ThreeIter<'a, 'h> {
+    /// The underlying memchr searcher.
+    searcher: &'a Three,
+    /// Generic iterator implementation.
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for ThreeIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+/// Return `true` if `x` contains any zero byte.
+///
+/// That is, this routine treats `x` as a register of 8-bit lanes and returns
+/// true when any of those lanes is `0`.
+///
+/// From "Matters Computational" by J. Arndt.
+#[inline(always)]
+fn has_zero_byte(x: usize) -> bool {
+    // "The idea is to subtract one from each of the bytes and then look for
+    // bytes where the borrow propagated all the way to the most significant
+    // bit."
+    const LO: usize = splat(0x01);
+    const HI: usize = splat(0x80);
+
+    (x.wrapping_sub(LO) & !x & HI) != 0
+}
+
+/// Repeat the given byte into a word size number. That is, every 8 bits
+/// is equivalent to the given byte. For example, if `b` is `\x4E` or
+/// `01001110` in binary, then the returned value on a 32-bit system would be:
+/// `01001110_01001110_01001110_01001110`.
+#[inline(always)]
+const fn splat(b: u8) -> usize {
+    // TODO: use `usize::from` once it can be used in const context.
+    (b as usize) * (usize::MAX / 255)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    define_memchr_quickcheck!(super, try_new);
+
+    #[test]
+    fn forward_one() {
+        crate::tests::memchr::Runner::new(1).forward_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0]).iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_one() {
+        crate::tests::memchr::Runner::new(1).reverse_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0]).iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn count_one() {
+        crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| {
+            Some(One::new(needles[0]).iter(haystack).count())
+        })
+    }
+
+    #[test]
+    fn forward_two() {
+        crate::tests::memchr::Runner::new(2).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2).iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_two() {
+        crate::tests::memchr::Runner::new(2).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2).iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn forward_three() {
+        crate::tests::memchr::Runner::new(3).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3).iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_three() {
+        crate::tests::memchr::Runner::new(3).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3).iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    // This was found by quickcheck in the course of refactoring this crate
+    // after memchr 2.5.0.
+    #[test]
+    fn regression_double_ended_iterator() {
+        let finder = One::new(b'a');
+        let haystack = "a";
+        let mut it = finder.iter(haystack.as_bytes());
+        assert_eq!(Some(0), it.next());
+        assert_eq!(None, it.next_back());
+    }
+
+    // This regression test was caught by ripgrep's test suite on i686 when
+    // upgrading to memchr 2.6. Namely, something about the \x0B bytes here
+    // screws with the SWAR counting approach I was using. This regression test
+    // prompted me to remove the SWAR counting approach and just replace it
+    // with a byte-at-a-time loop.
+    #[test]
+    fn regression_count_new_lines() {
+        let haystack = "01234567\x0b\n\x0b\n\x0b\n\x0b\nx";
+        let count = One::new(b'\n').count(haystack.as_bytes());
+        assert_eq!(4, count);
+    }
+}
diff --git a/vendor/memchr/src/arch/all/mod.rs b/vendor/memchr/src/arch/all/mod.rs
new file mode 100644
index 0000000..559cb75
--- /dev/null
+++ b/vendor/memchr/src/arch/all/mod.rs
@@ -0,0 +1,234 @@
+/*!
+Contains architecture independent routines.
+
+These routines are often used as a "fallback" implementation when the more
+specialized architecture dependent routines are unavailable.
+*/
+
+pub mod memchr;
+pub mod packedpair;
+pub mod rabinkarp;
+#[cfg(feature = "alloc")]
+pub mod shiftor;
+pub mod twoway;
+
+/// Returns true if and only if `needle` is a prefix of `haystack`.
+///
+/// This uses a latency optimized variant of `memcmp` internally which *might*
+/// make this faster for very short strings.
+///
+/// # Inlining
+///
+/// This routine is marked `inline(always)`. If you want to call this function
+/// in a way that is not always inlined, you'll need to wrap a call to it in
+/// another function that is marked as `inline(never)` or just `inline`.
+#[inline(always)]
+pub fn is_prefix(haystack: &[u8], needle: &[u8]) -> bool {
+    needle.len() <= haystack.len()
+        && is_equal(&haystack[..needle.len()], needle)
+}
+
+/// Returns true if and only if `needle` is a suffix of `haystack`.
+///
+/// This uses a latency optimized variant of `memcmp` internally which *might*
+/// make this faster for very short strings.
+///
+/// # Inlining
+///
+/// This routine is marked `inline(always)`. If you want to call this function
+/// in a way that is not always inlined, you'll need to wrap a call to it in
+/// another function that is marked as `inline(never)` or just `inline`.
+#[inline(always)]
+pub fn is_suffix(haystack: &[u8], needle: &[u8]) -> bool {
+    needle.len() <= haystack.len()
+        && is_equal(&haystack[haystack.len() - needle.len()..], needle)
+}
+
+/// Compare corresponding bytes in `x` and `y` for equality.
+///
+/// That is, this returns true if and only if `x.len() == y.len()` and
+/// `x[i] == y[i]` for all `0 <= i < x.len()`.
+///
+/// # Inlining
+///
+/// This routine is marked `inline(always)`. If you want to call this function
+/// in a way that is not always inlined, you'll need to wrap a call to it in
+/// another function that is marked as `inline(never)` or just `inline`.
+///
+/// # Motivation
+///
+/// Why not use slice equality instead? Well, slice equality usually results in
+/// a call out to the current platform's `libc` which might not be inlineable
+/// or have other overhead. This routine isn't guaranteed to be a win, but it
+/// might be in some cases.
+#[inline(always)]
+pub fn is_equal(x: &[u8], y: &[u8]) -> bool {
+    if x.len() != y.len() {
+        return false;
+    }
+    // SAFETY: Our pointers are derived directly from borrowed slices which
+    // uphold all of our safety guarantees except for length. We account for
+    // length with the check above.
+    unsafe { is_equal_raw(x.as_ptr(), y.as_ptr(), x.len()) }
+}
+
+/// Compare `n` bytes at the given pointers for equality.
+///
+/// This returns true if and only if `*x.add(i) == *y.add(i)` for all
+/// `0 <= i < n`.
+///
+/// # Inlining
+///
+/// This routine is marked `inline(always)`. If you want to call this function
+/// in a way that is not always inlined, you'll need to wrap a call to it in
+/// another function that is marked as `inline(never)` or just `inline`.
+///
+/// # Motivation
+///
+/// Why not use slice equality instead? Well, slice equality usually results in
+/// a call out to the current platform's `libc` which might not be inlineable
+/// or have other overhead. This routine isn't guaranteed to be a win, but it
+/// might be in some cases.
+///
+/// # Safety
+///
+/// * Both `x` and `y` must be valid for reads of up to `n` bytes.
+/// * Both `x` and `y` must point to an initialized value.
+/// * Both `x` and `y` must each point to an allocated object and
+/// must either be in bounds or at most one byte past the end of the
+/// allocated object. `x` and `y` do not need to point to the same allocated
+/// object, but they may.
+/// * Both `x` and `y` must be _derived from_ a pointer to their respective
+/// allocated objects.
+/// * The distance between `x` and `x+n` must not overflow `isize`. Similarly
+/// for `y` and `y+n`.
+/// * The distance being in bounds must not rely on "wrapping around" the
+/// address space.
+#[inline(always)]
+pub unsafe fn is_equal_raw(
+    mut x: *const u8,
+    mut y: *const u8,
+    mut n: usize,
+) -> bool {
+    // When we have 4 or more bytes to compare, then proceed in chunks of 4 at
+    // a time using unaligned loads.
+    //
+    // Also, why do 4 byte loads instead of, say, 8 byte loads? The reason is
+    // that this particular version of memcmp is likely to be called with tiny
+    // needles. That means that if we do 8 byte loads, then a higher proportion
+    // of memcmp calls will use the slower variant above. With that said, this
+    // is a hypothesis and is only loosely supported by benchmarks. There's
+    // likely some improvement that could be made here. The main thing here
+    // though is to optimize for latency, not throughput.
+
+    // SAFETY: The caller is responsible for ensuring the pointers we get are
+    // valid and readable for at least `n` bytes. We also do unaligned loads,
+    // so there's no need to ensure we're aligned. (This is justified by this
+    // routine being specifically for short strings.)
+    while n >= 4 {
+        let vx = x.cast::<u32>().read_unaligned();
+        let vy = y.cast::<u32>().read_unaligned();
+        if vx != vy {
+            return false;
+        }
+        x = x.add(4);
+        y = y.add(4);
+        n -= 4;
+    }
+    // If we don't have enough bytes to do 4-byte at a time loads, then
+    // do partial loads. Note that I used to have a byte-at-a-time
+    // loop here and that turned out to be quite a bit slower for the
+    // memmem/pathological/defeat-simple-vector-alphabet benchmark.
+    if n >= 2 {
+        let vx = x.cast::<u16>().read_unaligned();
+        let vy = y.cast::<u16>().read_unaligned();
+        if vx != vy {
+            return false;
+        }
+        x = x.add(2);
+        y = y.add(2);
+        n -= 2;
+    }
+    if n > 0 {
+        if x.read() != y.read() {
+            return false;
+        }
+    }
+    true
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn equals_different_lengths() {
+        assert!(!is_equal(b"", b"a"));
+        assert!(!is_equal(b"a", b""));
+        assert!(!is_equal(b"ab", b"a"));
+        assert!(!is_equal(b"a", b"ab"));
+    }
+
+    #[test]
+    fn equals_mismatch() {
+        let one_mismatch = [
+            (&b"a"[..], &b"x"[..]),
+            (&b"ab"[..], &b"ax"[..]),
+            (&b"abc"[..], &b"abx"[..]),
+            (&b"abcd"[..], &b"abcx"[..]),
+            (&b"abcde"[..], &b"abcdx"[..]),
+            (&b"abcdef"[..], &b"abcdex"[..]),
+            (&b"abcdefg"[..], &b"abcdefx"[..]),
+            (&b"abcdefgh"[..], &b"abcdefgx"[..]),
+            (&b"abcdefghi"[..], &b"abcdefghx"[..]),
+            (&b"abcdefghij"[..], &b"abcdefghix"[..]),
+            (&b"abcdefghijk"[..], &b"abcdefghijx"[..]),
+            (&b"abcdefghijkl"[..], &b"abcdefghijkx"[..]),
+            (&b"abcdefghijklm"[..], &b"abcdefghijklx"[..]),
+            (&b"abcdefghijklmn"[..], &b"abcdefghijklmx"[..]),
+        ];
+        for (x, y) in one_mismatch {
+            assert_eq!(x.len(), y.len(), "lengths should match");
+            assert!(!is_equal(x, y));
+            assert!(!is_equal(y, x));
+        }
+    }
+
+    #[test]
+    fn equals_yes() {
+        assert!(is_equal(b"", b""));
+        assert!(is_equal(b"a", b"a"));
+        assert!(is_equal(b"ab", b"ab"));
+        assert!(is_equal(b"abc", b"abc"));
+        assert!(is_equal(b"abcd", b"abcd"));
+        assert!(is_equal(b"abcde", b"abcde"));
+        assert!(is_equal(b"abcdef", b"abcdef"));
+        assert!(is_equal(b"abcdefg", b"abcdefg"));
+        assert!(is_equal(b"abcdefgh", b"abcdefgh"));
+        assert!(is_equal(b"abcdefghi", b"abcdefghi"));
+    }
+
+    #[test]
+    fn prefix() {
+        assert!(is_prefix(b"", b""));
+        assert!(is_prefix(b"a", b""));
+        assert!(is_prefix(b"ab", b""));
+        assert!(is_prefix(b"foo", b"foo"));
+        assert!(is_prefix(b"foobar", b"foo"));
+
+        assert!(!is_prefix(b"foo", b"fob"));
+        assert!(!is_prefix(b"foobar", b"fob"));
+    }
+
+    #[test]
+    fn suffix() {
+        assert!(is_suffix(b"", b""));
+        assert!(is_suffix(b"a", b""));
+        assert!(is_suffix(b"ab", b""));
+        assert!(is_suffix(b"foo", b"foo"));
+        assert!(is_suffix(b"foobar", b"bar"));
+
+        assert!(!is_suffix(b"foo", b"goo"));
+        assert!(!is_suffix(b"foobar", b"gar"));
+    }
+}
diff --git a/vendor/memchr/src/arch/all/packedpair/default_rank.rs b/vendor/memchr/src/arch/all/packedpair/default_rank.rs
new file mode 100644
index 0000000..6aa3895
--- /dev/null
+++ b/vendor/memchr/src/arch/all/packedpair/default_rank.rs
@@ -0,0 +1,258 @@
+pub(crate) const RANK: [u8; 256] = [
+    55,  // '\x00'
+    52,  // '\x01'
+    51,  // '\x02'
+    50,  // '\x03'
+    49,  // '\x04'
+    48,  // '\x05'
+    47,  // '\x06'
+    46,  // '\x07'
+    45,  // '\x08'
+    103, // '\t'
+    242, // '\n'
+    66,  // '\x0b'
+    67,  // '\x0c'
+    229, // '\r'
+    44,  // '\x0e'
+    43,  // '\x0f'
+    42,  // '\x10'
+    41,  // '\x11'
+    40,  // '\x12'
+    39,  // '\x13'
+    38,  // '\x14'
+    37,  // '\x15'
+    36,  // '\x16'
+    35,  // '\x17'
+    34,  // '\x18'
+    33,  // '\x19'
+    56,  // '\x1a'
+    32,  // '\x1b'
+    31,  // '\x1c'
+    30,  // '\x1d'
+    29,  // '\x1e'
+    28,  // '\x1f'
+    255, // ' '
+    148, // '!'
+    164, // '"'
+    149, // '#'
+    136, // '$'
+    160, // '%'
+    155, // '&'
+    173, // "'"
+    221, // '('
+    222, // ')'
+    134, // '*'
+    122, // '+'
+    232, // ','
+    202, // '-'
+    215, // '.'
+    224, // '/'
+    208, // '0'
+    220, // '1'
+    204, // '2'
+    187, // '3'
+    183, // '4'
+    179, // '5'
+    177, // '6'
+    168, // '7'
+    178, // '8'
+    200, // '9'
+    226, // ':'
+    195, // ';'
+    154, // '<'
+    184, // '='
+    174, // '>'
+    126, // '?'
+    120, // '@'
+    191, // 'A'
+    157, // 'B'
+    194, // 'C'
+    170, // 'D'
+    189, // 'E'
+    162, // 'F'
+    161, // 'G'
+    150, // 'H'
+    193, // 'I'
+    142, // 'J'
+    137, // 'K'
+    171, // 'L'
+    176, // 'M'
+    185, // 'N'
+    167, // 'O'
+    186, // 'P'
+    112, // 'Q'
+    175, // 'R'
+    192, // 'S'
+    188, // 'T'
+    156, // 'U'
+    140, // 'V'
+    143, // 'W'
+    123, // 'X'
+    133, // 'Y'
+    128, // 'Z'
+    147, // '['
+    138, // '\\'
+    146, // ']'
+    114, // '^'
+    223, // '_'
+    151, // '`'
+    249, // 'a'
+    216, // 'b'
+    238, // 'c'
+    236, // 'd'
+    253, // 'e'
+    227, // 'f'
+    218, // 'g'
+    230, // 'h'
+    247, // 'i'
+    135, // 'j'
+    180, // 'k'
+    241, // 'l'
+    233, // 'm'
+    246, // 'n'
+    244, // 'o'
+    231, // 'p'
+    139, // 'q'
+    245, // 'r'
+    243, // 's'
+    251, // 't'
+    235, // 'u'
+    201, // 'v'
+    196, // 'w'
+    240, // 'x'
+    214, // 'y'
+    152, // 'z'
+    182, // '{'
+    205, // '|'
+    181, // '}'
+    127, // '~'
+    27,  // '\x7f'
+    212, // '\x80'
+    211, // '\x81'
+    210, // '\x82'
+    213, // '\x83'
+    228, // '\x84'
+    197, // '\x85'
+    169, // '\x86'
+    159, // '\x87'
+    131, // '\x88'
+    172, // '\x89'
+    105, // '\x8a'
+    80,  // '\x8b'
+    98,  // '\x8c'
+    96,  // '\x8d'
+    97,  // '\x8e'
+    81,  // '\x8f'
+    207, // '\x90'
+    145, // '\x91'
+    116, // '\x92'
+    115, // '\x93'
+    144, // '\x94'
+    130, // '\x95'
+    153, // '\x96'
+    121, // '\x97'
+    107, // '\x98'
+    132, // '\x99'
+    109, // '\x9a'
+    110, // '\x9b'
+    124, // '\x9c'
+    111, // '\x9d'
+    82,  // '\x9e'
+    108, // '\x9f'
+    118, // '\xa0'
+    141, // '¡'
+    113, // '¢'
+    129, // '£'
+    119, // '¤'
+    125, // '¥'
+    165, // '¦'
+    117, // '§'
+    92,  // '¨'
+    106, // '©'
+    83,  // 'ª'
+    72,  // '«'
+    99,  // '¬'
+    93,  // '\xad'
+    65,  // '®'
+    79,  // '¯'
+    166, // '°'
+    237, // '±'
+    163, // '²'
+    199, // '³'
+    190, // '´'
+    225, // 'µ'
+    209, // '¶'
+    203, // '·'
+    198, // '¸'
+    217, // '¹'
+    219, // 'º'
+    206, // '»'
+    234, // '¼'
+    248, // '½'
+    158, // '¾'
+    239, // '¿'
+    255, // 'À'
+    255, // 'Á'
+    255, // 'Â'
+    255, // 'Ã'
+    255, // 'Ä'
+    255, // 'Å'
+    255, // 'Æ'
+    255, // 'Ç'
+    255, // 'È'
+    255, // 'É'
+    255, // 'Ê'
+    255, // 'Ë'
+    255, // 'Ì'
+    255, // 'Í'
+    255, // 'Î'
+    255, // 'Ï'
+    255, // 'Ð'
+    255, // 'Ñ'
+    255, // 'Ò'
+    255, // 'Ó'
+    255, // 'Ô'
+    255, // 'Õ'
+    255, // 'Ö'
+    255, // '×'
+    255, // 'Ø'
+    255, // 'Ù'
+    255, // 'Ú'
+    255, // 'Û'
+    255, // 'Ü'
+    255, // 'Ý'
+    255, // 'Þ'
+    255, // 'ß'
+    255, // 'à'
+    255, // 'á'
+    255, // 'â'
+    255, // 'ã'
+    255, // 'ä'
+    255, // 'å'
+    255, // 'æ'
+    255, // 'ç'
+    255, // 'è'
+    255, // 'é'
+    255, // 'ê'
+    255, // 'ë'
+    255, // 'ì'
+    255, // 'í'
+    255, // 'î'
+    255, // 'ï'
+    255, // 'ð'
+    255, // 'ñ'
+    255, // 'ò'
+    255, // 'ó'
+    255, // 'ô'
+    255, // 'õ'
+    255, // 'ö'
+    255, // '÷'
+    255, // 'ø'
+    255, // 'ù'
+    255, // 'ú'
+    255, // 'û'
+    255, // 'ü'
+    255, // 'ý'
+    255, // 'þ'
+    255, // 'ÿ'
+];
diff --git a/vendor/memchr/src/arch/all/packedpair/mod.rs b/vendor/memchr/src/arch/all/packedpair/mod.rs
new file mode 100644
index 0000000..148a985
--- /dev/null
+++ b/vendor/memchr/src/arch/all/packedpair/mod.rs
@@ -0,0 +1,359 @@
+/*!
+Provides an architecture independent implementation of the "packed pair"
+algorithm.
+
+The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main
+difference is that it (by default) uses a background distribution of byte
+frequencies to heuristically select the pair of bytes to search for. Note that
+this module provides an architecture independent version that doesn't do as
+good of a job keeping the search for candidates inside a SIMD hot path. It
+however can be good enough in many circumstances.
+
+[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last
+*/
+
+use crate::memchr;
+
+mod default_rank;
+
+/// An architecture independent "packed pair" finder.
+///
+/// This finder picks two bytes that it believes have high predictive power for
+/// indicating an overall match of a needle. At search time, it reports offsets
+/// where the needle could match based on whether the pair of bytes it chose
+/// match.
+///
+/// This is architecture independent because it utilizes `memchr` to find the
+/// occurrence of one of the bytes in the pair, and then checks whether the
+/// second byte matches. If it does, in the case of [`Finder::find_prefilter`],
+/// the location at which the needle could match is returned.
+///
+/// It is generally preferred to use architecture specific routines for a
+/// "packed pair" prefilter, but this can be a useful fallback when the
+/// architecture independent routines are unavailable.
+#[derive(Clone, Copy, Debug)]
+pub struct Finder {
+    pair: Pair,
+    byte1: u8,
+    byte2: u8,
+}
+
+impl Finder {
+    /// Create a new prefilter that reports possible locations where the given
+    /// needle matches.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Option<Finder> {
+        Finder::with_pair(needle, Pair::new(needle)?)
+    }
+
+    /// Create a new prefilter using the pair given.
+    ///
+    /// If the prefilter could not be constructed, then `None` is returned.
+    ///
+    /// This constructor permits callers to control precisely which pair of
+    /// bytes is used as a predicate.
+    #[inline]
+    pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> {
+        let byte1 = needle[usize::from(pair.index1())];
+        let byte2 = needle[usize::from(pair.index2())];
+        // Currently this can never fail so we could just return a Finder,
+        // but it's conceivable this could change.
+        Some(Finder { pair, byte1, byte2 })
+    }
+
+    /// Run this finder on the given haystack as a prefilter.
+    ///
+    /// If a candidate match is found, then an offset where the needle *could*
+    /// begin in the haystack is returned.
+    #[inline]
+    pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> {
+        let mut i = 0;
+        let index1 = usize::from(self.pair.index1());
+        let index2 = usize::from(self.pair.index2());
+        loop {
+            // Use a fast vectorized implementation to skip to the next
+            // occurrence of the rarest byte (heuristically chosen) in the
+            // needle.
+            i += memchr(self.byte1, &haystack[i..])?;
+            let found = i;
+            i += 1;
+
+            // If we can't align our first byte match with the haystack, then a
+            // match is impossible.
+            let aligned1 = match found.checked_sub(index1) {
+                None => continue,
+                Some(aligned1) => aligned1,
+            };
+
+            // Now align the second byte match with the haystack. A mismatch
+            // means that a match is impossible.
+            let aligned2 = match aligned1.checked_add(index2) {
+                None => continue,
+                Some(aligned_index2) => aligned_index2,
+            };
+            if haystack.get(aligned2).map_or(true, |&b| b != self.byte2) {
+                continue;
+            }
+
+            // We've done what we can. There might be a match here.
+            return Some(aligned1);
+        }
+    }
+
+    /// Returns the pair of offsets (into the needle) used to check as a
+    /// predicate before confirming whether a needle exists at a particular
+    /// position.
+    #[inline]
+    pub fn pair(&self) -> &Pair {
+        &self.pair
+    }
+}
+
+/// A pair of byte offsets into a needle to use as a predicate.
+///
+/// This pair is used as a predicate to quickly filter out positions in a
+/// haystack in which a needle cannot match. In some cases, this pair can even
+/// be used in vector algorithms such that the vector algorithm only switches
+/// over to scalar code once this pair has been found.
+///
+/// A pair of offsets can be used in both substring search implementations and
+/// in prefilters. The former will report matches of a needle in a haystack
+/// where as the latter will only report possible matches of a needle.
+///
+/// The offsets are limited each to a maximum of 255 to keep memory usage low.
+/// Moreover, it's rarely advantageous to create a predicate using offsets
+/// greater than 255 anyway.
+///
+/// The only guarantee enforced on the pair of offsets is that they are not
+/// equivalent. It is not necessarily the case that `index1 < index2` for
+/// example. By convention, `index1` corresponds to the byte in the needle
+/// that is believed to be most the predictive. Note also that because of the
+/// requirement that the indices be both valid for the needle used to build
+/// the pair and not equal, it follows that a pair can only be constructed for
+/// needles with length at least 2.
+#[derive(Clone, Copy, Debug)]
+pub struct Pair {
+    index1: u8,
+    index2: u8,
+}
+
+impl Pair {
+    /// Create a new pair of offsets from the given needle.
+    ///
+    /// If a pair could not be created (for example, if the needle is too
+    /// short), then `None` is returned.
+    ///
+    /// This chooses the pair in the needle that is believed to be as
+    /// predictive of an overall match of the needle as possible.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Option<Pair> {
+        Pair::with_ranker(needle, DefaultFrequencyRank)
+    }
+
+    /// Create a new pair of offsets from the given needle and ranker.
+    ///
+    /// This permits the caller to choose a background frequency distribution
+    /// with which bytes are selected. The idea is to select a pair of bytes
+    /// that is believed to strongly predict a match in the haystack. This
+    /// usually means selecting bytes that occur rarely in a haystack.
+    ///
+    /// If a pair could not be created (for example, if the needle is too
+    /// short), then `None` is returned.
+    #[inline]
+    pub fn with_ranker<R: HeuristicFrequencyRank>(
+        needle: &[u8],
+        ranker: R,
+    ) -> Option<Pair> {
+        if needle.len() <= 1 {
+            return None;
+        }
+        // Find the rarest two bytes. We make them distinct indices by
+        // construction. (The actual byte value may be the same in degenerate
+        // cases, but that's OK.)
+        let (mut rare1, mut index1) = (needle[0], 0);
+        let (mut rare2, mut index2) = (needle[1], 1);
+        if ranker.rank(rare2) < ranker.rank(rare1) {
+            core::mem::swap(&mut rare1, &mut rare2);
+            core::mem::swap(&mut index1, &mut index2);
+        }
+        let max = usize::from(core::u8::MAX);
+        for (i, &b) in needle.iter().enumerate().take(max).skip(2) {
+            if ranker.rank(b) < ranker.rank(rare1) {
+                rare2 = rare1;
+                index2 = index1;
+                rare1 = b;
+                index1 = u8::try_from(i).unwrap();
+            } else if b != rare1 && ranker.rank(b) < ranker.rank(rare2) {
+                rare2 = b;
+                index2 = u8::try_from(i).unwrap();
+            }
+        }
+        // While not strictly required for how a Pair is normally used, we
+        // really don't want these to be equivalent. If they were, it would
+        // reduce the effectiveness of candidate searching using these rare
+        // bytes by increasing the rate of false positives.
+        assert_ne!(index1, index2);
+        Some(Pair { index1, index2 })
+    }
+
+    /// Create a new pair using the offsets given for the needle given.
+    ///
+    /// This bypasses any sort of heuristic process for choosing the offsets
+    /// and permits the caller to choose the offsets themselves.
+    ///
+    /// Indices are limited to valid `u8` values so that a `Pair` uses less
+    /// memory. It is not possible to create a `Pair` with offsets bigger than
+    /// `u8::MAX`. It's likely that such a thing is not needed, but if it is,
+    /// it's suggested to build your own bespoke algorithm because you're
+    /// likely working on a very niche case. (File an issue if this suggestion
+    /// does not make sense to you.)
+    ///
+    /// If a pair could not be created (for example, if the needle is too
+    /// short), then `None` is returned.
+    #[inline]
+    pub fn with_indices(
+        needle: &[u8],
+        index1: u8,
+        index2: u8,
+    ) -> Option<Pair> {
+        // While not strictly required for how a Pair is normally used, we
+        // really don't want these to be equivalent. If they were, it would
+        // reduce the effectiveness of candidate searching using these rare
+        // bytes by increasing the rate of false positives.
+        if index1 == index2 {
+            return None;
+        }
+        // Similarly, invalid indices means the Pair is invalid too.
+        if usize::from(index1) >= needle.len() {
+            return None;
+        }
+        if usize::from(index2) >= needle.len() {
+            return None;
+        }
+        Some(Pair { index1, index2 })
+    }
+
+    /// Returns the first offset of the pair.
+    #[inline]
+    pub fn index1(&self) -> u8 {
+        self.index1
+    }
+
+    /// Returns the second offset of the pair.
+    #[inline]
+    pub fn index2(&self) -> u8 {
+        self.index2
+    }
+}
+
+/// This trait allows the user to customize the heuristic used to determine the
+/// relative frequency of a given byte in the dataset being searched.
+///
+/// The use of this trait can have a dramatic impact on performance depending
+/// on the type of data being searched. The details of why are explained in the
+/// docs of [`crate::memmem::Prefilter`]. To summarize, the core algorithm uses
+/// a prefilter to quickly identify candidate matches that are later verified
+/// more slowly. This prefilter is implemented in terms of trying to find
+/// `rare` bytes at specific offsets that will occur less frequently in the
+/// dataset. While the concept of a `rare` byte is similar for most datasets,
+/// there are some specific datasets (like binary executables) that have
+/// dramatically different byte distributions. For these datasets customizing
+/// the byte frequency heuristic can have a massive impact on performance, and
+/// might even need to be done at runtime.
+///
+/// The default implementation of `HeuristicFrequencyRank` reads from the
+/// static frequency table defined in `src/memmem/byte_frequencies.rs`. This
+/// is optimal for most inputs, so if you are unsure of the impact of using a
+/// custom `HeuristicFrequencyRank` you should probably just use the default.
+///
+/// # Example
+///
+/// ```
+/// use memchr::{
+///     arch::all::packedpair::HeuristicFrequencyRank,
+///     memmem::FinderBuilder,
+/// };
+///
+/// /// A byte-frequency table that is good for scanning binary executables.
+/// struct Binary;
+///
+/// impl HeuristicFrequencyRank for Binary {
+///     fn rank(&self, byte: u8) -> u8 {
+///         const TABLE: [u8; 256] = [
+///             255, 128, 61, 43, 50, 41, 27, 28, 57, 15, 21, 13, 24, 17, 17,
+///             89, 58, 16, 11, 7, 14, 23, 7, 6, 24, 9, 6, 5, 9, 4, 7, 16,
+///             68, 11, 9, 6, 88, 7, 4, 4, 23, 9, 4, 8, 8, 5, 10, 4, 30, 11,
+///             9, 24, 11, 5, 5, 5, 19, 11, 6, 17, 9, 9, 6, 8,
+///             48, 58, 11, 14, 53, 40, 9, 9, 254, 35, 3, 6, 52, 23, 6, 6, 27,
+///             4, 7, 11, 14, 13, 10, 11, 11, 5, 2, 10, 16, 12, 6, 19,
+///             19, 20, 5, 14, 16, 31, 19, 7, 14, 20, 4, 4, 19, 8, 18, 20, 24,
+///             1, 25, 19, 58, 29, 10, 5, 15, 20, 2, 2, 9, 4, 3, 5,
+///             51, 11, 4, 53, 23, 39, 6, 4, 13, 81, 4, 186, 5, 67, 3, 2, 15,
+///             0, 0, 1, 3, 2, 0, 0, 5, 0, 0, 0, 2, 0, 0, 0,
+///             12, 2, 1, 1, 3, 1, 1, 1, 6, 1, 2, 1, 3, 1, 1, 2, 9, 1, 1, 0,
+///             2, 2, 4, 4, 11, 6, 7, 3, 6, 9, 4, 5,
+///             46, 18, 8, 18, 17, 3, 8, 20, 16, 10, 3, 7, 175, 4, 6, 7, 13,
+///             3, 7, 3, 3, 1, 3, 3, 10, 3, 1, 5, 2, 0, 1, 2,
+///             16, 3, 5, 1, 6, 1, 1, 2, 58, 20, 3, 14, 12, 2, 1, 3, 16, 3, 5,
+///             8, 3, 1, 8, 6, 17, 6, 5, 3, 8, 6, 13, 175,
+///         ];
+///         TABLE[byte as usize]
+///     }
+/// }
+/// // Create a new finder with the custom heuristic.
+/// let finder = FinderBuilder::new()
+///     .build_forward_with_ranker(Binary, b"\x00\x00\xdd\xdd");
+/// // Find needle with custom heuristic.
+/// assert!(finder.find(b"\x00\x00\x00\xdd\xdd").is_some());
+/// ```
+pub trait HeuristicFrequencyRank {
+    /// Return the heuristic frequency rank of the given byte. A lower rank
+    /// means the byte is believed to occur less frequently in the haystack.
+    ///
+    /// Some uses of this heuristic may treat arbitrary absolute rank values as
+    /// significant. For example, an implementation detail in this crate may
+    /// determine that heuristic prefilters are inappropriate if every byte in
+    /// the needle has a "high" rank.
+    fn rank(&self, byte: u8) -> u8;
+}
+
+/// The default byte frequency heuristic that is good for most haystacks.
+pub(crate) struct DefaultFrequencyRank;
+
+impl HeuristicFrequencyRank for DefaultFrequencyRank {
+    fn rank(&self, byte: u8) -> u8 {
+        self::default_rank::RANK[usize::from(byte)]
+    }
+}
+
+/// This permits passing any implementation of `HeuristicFrequencyRank` as a
+/// borrowed version of itself.
+impl<'a, R> HeuristicFrequencyRank for &'a R
+where
+    R: HeuristicFrequencyRank,
+{
+    fn rank(&self, byte: u8) -> u8 {
+        (**self).rank(byte)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn forward_packedpair() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            _index1: u8,
+            _index2: u8,
+        ) -> Option<Option<usize>> {
+            // We ignore the index positions requested since it winds up making
+            // this test too slow overall.
+            let f = Finder::new(needle)?;
+            Some(f.find_prefilter(haystack))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+}
diff --git a/vendor/memchr/src/arch/all/rabinkarp.rs b/vendor/memchr/src/arch/all/rabinkarp.rs
new file mode 100644
index 0000000..e0bafba
--- /dev/null
+++ b/vendor/memchr/src/arch/all/rabinkarp.rs
@@ -0,0 +1,390 @@
+/*!
+An implementation of the [Rabin-Karp substring search algorithm][rabinkarp].
+
+Rabin-Karp works by creating a hash of the needle provided and then computing
+a rolling hash for each needle sized window in the haystack. When the rolling
+hash matches the hash of the needle, a byte-wise comparison is done to check
+if a match exists. The worst case time complexity of Rabin-Karp is `O(m *
+n)` where `m ~ len(needle)` and `n ~ len(haystack)`. Its worst case space
+complexity is constant.
+
+The main utility of Rabin-Karp is that the searcher can be constructed very
+quickly with very little memory. This makes it especially useful when searching
+for small needles in small haystacks, as it might finish its search before a
+beefier algorithm (like Two-Way) even starts.
+
+[rabinkarp]: https://en.wikipedia.org/wiki/Rabin%E2%80%93Karp_algorithm
+*/
+
+/*
+(This was the comment I wrote for this module originally when it was not
+exposed. The comment still looks useful, but it's a bit in the weeds, so it's
+not public itself.)
+
+This module implements the classical Rabin-Karp substring search algorithm,
+with no extra frills. While its use would seem to break our time complexity
+guarantee of O(m+n) (RK's time complexity is O(mn)), we are careful to only
+ever use RK on a constant subset of haystacks. The main point here is that
+RK has good latency properties for small needles/haystacks. It's very quick
+to compute a needle hash and zip through the haystack when compared to
+initializing Two-Way, for example. And this is especially useful for cases
+where the haystack is just too short for vector instructions to do much good.
+
+The hashing function used here is the same one recommended by ESMAJ.
+
+Another choice instead of Rabin-Karp would be Shift-Or. But its latency
+isn't quite as good since its preprocessing time is a bit more expensive
+(both in practice and in theory). However, perhaps Shift-Or has a place
+somewhere else for short patterns. I think the main problem is that it
+requires space proportional to the alphabet and the needle. If we, for
+example, supported needles up to length 16, then the total table size would be
+len(alphabet)*size_of::<u16>()==512 bytes. Which isn't exactly small, and it's
+probably bad to put that on the stack. So ideally, we'd throw it on the heap,
+but we'd really like to write as much code without using alloc/std as possible.
+But maybe it's worth the special casing. It's a TODO to benchmark.
+
+Wikipedia has a decent explanation, if a bit heavy on the theory:
+https://en.wikipedia.org/wiki/Rabin%E2%80%93Karp_algorithm
+
+But ESMAJ provides something a bit more concrete:
+http://www-igm.univ-mlv.fr/~lecroq/string/node5.html
+
+Finally, aho-corasick uses Rabin-Karp for multiple pattern match in some cases:
+https://github.com/BurntSushi/aho-corasick/blob/3852632f10587db0ff72ef29e88d58bf305a0946/src/packed/rabinkarp.rs
+*/
+
+use crate::ext::Pointer;
+
+/// A forward substring searcher using the Rabin-Karp algorithm.
+///
+/// Note that, as a lower level API, a `Finder` does not have access to the
+/// needle it was constructed with. For this reason, executing a search
+/// with a `Finder` requires passing both the needle and the haystack,
+/// where the needle is exactly equivalent to the one given to the `Finder`
+/// at construction time. This design was chosen so that callers can have
+/// more precise control over where and how many times a needle is stored.
+/// For example, in cases where Rabin-Karp is just one of several possible
+/// substring search algorithms.
+#[derive(Clone, Debug)]
+pub struct Finder {
+    /// The actual hash.
+    hash: Hash,
+    /// The factor needed to multiply a byte by in order to subtract it from
+    /// the hash. It is defined to be 2^(n-1) (using wrapping exponentiation),
+    /// where n is the length of the needle. This is how we "remove" a byte
+    /// from the hash once the hash window rolls past it.
+    hash_2pow: u32,
+}
+
+impl Finder {
+    /// Create a new Rabin-Karp forward searcher for the given `needle`.
+    ///
+    /// The needle may be empty. The empty needle matches at every byte offset.
+    ///
+    /// Note that callers must pass the same needle to all search calls using
+    /// this `Finder`.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Finder {
+        let mut s = Finder { hash: Hash::new(), hash_2pow: 1 };
+        let first_byte = match needle.get(0) {
+            None => return s,
+            Some(&first_byte) => first_byte,
+        };
+        s.hash.add(first_byte);
+        for b in needle.iter().copied().skip(1) {
+            s.hash.add(b);
+            s.hash_2pow = s.hash_2pow.wrapping_shl(1);
+        }
+        s
+    }
+
+    /// Return the first occurrence of the `needle` in the `haystack`
+    /// given. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The `needle` provided must match the needle given to this finder at
+    /// construction time.
+    ///
+    /// The maximum value this can return is `haystack.len()`, which can only
+    /// occur when the needle and haystack both have length zero. Otherwise,
+    /// for non-empty haystacks, the maximum value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        unsafe {
+            let hstart = haystack.as_ptr();
+            let hend = hstart.add(haystack.len());
+            let nstart = needle.as_ptr();
+            let nend = nstart.add(needle.len());
+            let found = self.find_raw(hstart, hend, nstart, nend)?;
+            Some(found.distance(hstart))
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `<= end`. The pointer returned is only ever equivalent
+    /// to `end` when both the needle and haystack are empty. (That is, the
+    /// empty string matches the empty string.)
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// Note that `start` and `end` below refer to both pairs of pointers given
+    /// to this routine. That is, the conditions apply to both `hstart`/`hend`
+    /// and `nstart`/`nend`.
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    /// * It must be the case that `start <= end`.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        hstart: *const u8,
+        hend: *const u8,
+        nstart: *const u8,
+        nend: *const u8,
+    ) -> Option<*const u8> {
+        let hlen = hend.distance(hstart);
+        let nlen = nend.distance(nstart);
+        if nlen > hlen {
+            return None;
+        }
+        let mut cur = hstart;
+        let end = hend.sub(nlen);
+        let mut hash = Hash::forward(cur, cur.add(nlen));
+        loop {
+            if self.hash == hash && is_equal_raw(cur, nstart, nlen) {
+                return Some(cur);
+            }
+            if cur >= end {
+                return None;
+            }
+            hash.roll(self, cur.read(), cur.add(nlen).read());
+            cur = cur.add(1);
+        }
+    }
+}
+
+/// A reverse substring searcher using the Rabin-Karp algorithm.
+#[derive(Clone, Debug)]
+pub struct FinderRev(Finder);
+
+impl FinderRev {
+    /// Create a new Rabin-Karp reverse searcher for the given `needle`.
+    #[inline]
+    pub fn new(needle: &[u8]) -> FinderRev {
+        let mut s = FinderRev(Finder { hash: Hash::new(), hash_2pow: 1 });
+        let last_byte = match needle.last() {
+            None => return s,
+            Some(&last_byte) => last_byte,
+        };
+        s.0.hash.add(last_byte);
+        for b in needle.iter().rev().copied().skip(1) {
+            s.0.hash.add(b);
+            s.0.hash_2pow = s.0.hash_2pow.wrapping_shl(1);
+        }
+        s
+    }
+
+    /// Return the last occurrence of the `needle` in the `haystack`
+    /// given. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The `needle` provided must match the needle given to this finder at
+    /// construction time.
+    ///
+    /// The maximum value this can return is `haystack.len()`, which can only
+    /// occur when the needle and haystack both have length zero. Otherwise,
+    /// for non-empty haystacks, the maximum value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        unsafe {
+            let hstart = haystack.as_ptr();
+            let hend = hstart.add(haystack.len());
+            let nstart = needle.as_ptr();
+            let nend = nstart.add(needle.len());
+            let found = self.rfind_raw(hstart, hend, nstart, nend)?;
+            Some(found.distance(hstart))
+        }
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `<= end`. The pointer returned is only ever equivalent
+    /// to `end` when both the needle and haystack are empty. (That is, the
+    /// empty string matches the empty string.)
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// Note that `start` and `end` below refer to both pairs of pointers given
+    /// to this routine. That is, the conditions apply to both `hstart`/`hend`
+    /// and `nstart`/`nend`.
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    /// * It must be the case that `start <= end`.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        hstart: *const u8,
+        hend: *const u8,
+        nstart: *const u8,
+        nend: *const u8,
+    ) -> Option<*const u8> {
+        let hlen = hend.distance(hstart);
+        let nlen = nend.distance(nstart);
+        if nlen > hlen {
+            return None;
+        }
+        let mut cur = hend.sub(nlen);
+        let start = hstart;
+        let mut hash = Hash::reverse(cur, cur.add(nlen));
+        loop {
+            if self.0.hash == hash && is_equal_raw(cur, nstart, nlen) {
+                return Some(cur);
+            }
+            if cur <= start {
+                return None;
+            }
+            cur = cur.sub(1);
+            hash.roll(&self.0, cur.add(nlen).read(), cur.read());
+        }
+    }
+}
+
+/// Whether RK is believed to be very fast for the given needle/haystack.
+#[inline]
+pub(crate) fn is_fast(haystack: &[u8], _needle: &[u8]) -> bool {
+    haystack.len() < 16
+}
+
+/// A Rabin-Karp hash. This might represent the hash of a needle, or the hash
+/// of a rolling window in the haystack.
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
+struct Hash(u32);
+
+impl Hash {
+    /// Create a new hash that represents the empty string.
+    #[inline(always)]
+    fn new() -> Hash {
+        Hash(0)
+    }
+
+    /// Create a new hash from the bytes given for use in forward searches.
+    ///
+    /// # Safety
+    ///
+    /// The given pointers must be valid to read from within their range.
+    #[inline(always)]
+    unsafe fn forward(mut start: *const u8, end: *const u8) -> Hash {
+        let mut hash = Hash::new();
+        while start < end {
+            hash.add(start.read());
+            start = start.add(1);
+        }
+        hash
+    }
+
+    /// Create a new hash from the bytes given for use in reverse searches.
+    ///
+    /// # Safety
+    ///
+    /// The given pointers must be valid to read from within their range.
+    #[inline(always)]
+    unsafe fn reverse(start: *const u8, mut end: *const u8) -> Hash {
+        let mut hash = Hash::new();
+        while start < end {
+            end = end.sub(1);
+            hash.add(end.read());
+        }
+        hash
+    }
+
+    /// Add 'new' and remove 'old' from this hash. The given needle hash should
+    /// correspond to the hash computed for the needle being searched for.
+    ///
+    /// This is meant to be used when the rolling window of the haystack is
+    /// advanced.
+    #[inline(always)]
+    fn roll(&mut self, finder: &Finder, old: u8, new: u8) {
+        self.del(finder, old);
+        self.add(new);
+    }
+
+    /// Add a byte to this hash.
+    #[inline(always)]
+    fn add(&mut self, byte: u8) {
+        self.0 = self.0.wrapping_shl(1).wrapping_add(u32::from(byte));
+    }
+
+    /// Remove a byte from this hash. The given needle hash should correspond
+    /// to the hash computed for the needle being searched for.
+    #[inline(always)]
+    fn del(&mut self, finder: &Finder, byte: u8) {
+        let factor = finder.hash_2pow;
+        self.0 = self.0.wrapping_sub(u32::from(byte).wrapping_mul(factor));
+    }
+}
+
+/// Returns true when `x[i] == y[i]` for all `0 <= i < n`.
+///
+/// We forcefully don't inline this to hint at the compiler that it is unlikely
+/// to be called. This causes the inner rabinkarp loop above to be a bit
+/// tighter and leads to some performance improvement. See the
+/// memmem/krate/prebuilt/sliceslice-words/words benchmark.
+///
+/// # Safety
+///
+/// Same as `crate::arch::all::is_equal_raw`.
+#[cold]
+#[inline(never)]
+unsafe fn is_equal_raw(x: *const u8, y: *const u8, n: usize) -> bool {
+    crate::arch::all::is_equal_raw(x, y, n)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    define_substring_forward_quickcheck!(|h, n| Some(
+        Finder::new(n).find(h, n)
+    ));
+    define_substring_reverse_quickcheck!(|h, n| Some(
+        FinderRev::new(n).rfind(h, n)
+    ));
+
+    #[test]
+    fn forward() {
+        crate::tests::substring::Runner::new()
+            .fwd(|h, n| Some(Finder::new(n).find(h, n)))
+            .run();
+    }
+
+    #[test]
+    fn reverse() {
+        crate::tests::substring::Runner::new()
+            .rev(|h, n| Some(FinderRev::new(n).rfind(h, n)))
+            .run();
+    }
+}
diff --git a/vendor/memchr/src/arch/all/shiftor.rs b/vendor/memchr/src/arch/all/shiftor.rs
new file mode 100644
index 0000000..b690564
--- /dev/null
+++ b/vendor/memchr/src/arch/all/shiftor.rs
@@ -0,0 +1,89 @@
+/*!
+An implementation of the [Shift-Or substring search algorithm][shiftor].
+
+[shiftor]: https://en.wikipedia.org/wiki/Bitap_algorithm
+*/
+
+use alloc::boxed::Box;
+
+/// The type of our mask.
+///
+/// While we don't expose anyway to configure this in the public API, if one
+/// really needs less memory usage or support for longer needles, then it is
+/// suggested to copy the code from this module and modify it to fit your
+/// needs. The code below is written to be correct regardless of whether Mask
+/// is a u8, u16, u32, u64 or u128.
+type Mask = u16;
+
+/// A forward substring searcher using the Shift-Or algorithm.
+#[derive(Debug)]
+pub struct Finder {
+    masks: Box<[Mask; 256]>,
+    needle_len: usize,
+}
+
+impl Finder {
+    const MAX_NEEDLE_LEN: usize = (Mask::BITS - 1) as usize;
+
+    /// Create a new Shift-Or forward searcher for the given `needle`.
+    ///
+    /// The needle may be empty. The empty needle matches at every byte offset.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Option<Finder> {
+        let needle_len = needle.len();
+        if needle_len > Finder::MAX_NEEDLE_LEN {
+            // A match is found when bit 7 is set in 'result' in the search
+            // routine below. So our needle can't be bigger than 7. We could
+            // permit bigger needles by using u16, u32 or u64 for our mask
+            // entries. But this is all we need for this example.
+            return None;
+        }
+        let mut searcher = Finder { masks: Box::from([!0; 256]), needle_len };
+        for (i, &byte) in needle.iter().enumerate() {
+            searcher.masks[usize::from(byte)] &= !(1 << i);
+        }
+        Some(searcher)
+    }
+
+    /// Return the first occurrence of the needle given to `Finder::new` in
+    /// the `haystack` given. If no such occurrence exists, then `None` is
+    /// returned.
+    ///
+    /// Unlike most other substring search implementations in this crate, this
+    /// finder does not require passing the needle at search time. A match can
+    /// be determined without the needle at all since the required information
+    /// is already encoded into this finder at construction time.
+    ///
+    /// The maximum value this can return is `haystack.len()`, which can only
+    /// occur when the needle and haystack both have length zero. Otherwise,
+    /// for non-empty haystacks, the maximum value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        if self.needle_len == 0 {
+            return Some(0);
+        }
+        let mut result = !1;
+        for (i, &byte) in haystack.iter().enumerate() {
+            result |= self.masks[usize::from(byte)];
+            result <<= 1;
+            if result & (1 << self.needle_len) == 0 {
+                return Some(i + 1 - self.needle_len);
+            }
+        }
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    define_substring_forward_quickcheck!(|h, n| Some(Finder::new(n)?.find(h)));
+
+    #[test]
+    fn forward() {
+        crate::tests::substring::Runner::new()
+            .fwd(|h, n| Some(Finder::new(n)?.find(h)))
+            .run();
+    }
+}
diff --git a/vendor/memchr/src/arch/all/twoway.rs b/vendor/memchr/src/arch/all/twoway.rs
new file mode 100644
index 0000000..0df3b4a
--- /dev/null
+++ b/vendor/memchr/src/arch/all/twoway.rs
@@ -0,0 +1,877 @@
+/*!
+An implementation of the [Two-Way substring search algorithm][two-way].
+
+[`Finder`] can be built for forward searches, while [`FinderRev`] can be built
+for reverse searches.
+
+Two-Way makes for a nice general purpose substring search algorithm because of
+its time and space complexity properties. It also performs well in practice.
+Namely, with `m = len(needle)` and `n = len(haystack)`, Two-Way takes `O(m)`
+time to create a finder, `O(1)` space and `O(n)` search time. In other words,
+the preprocessing step is quick, doesn't require any heap memory and the worst
+case search time is guaranteed to be linear in the haystack regardless of the
+size of the needle.
+
+While vector algorithms will usually beat Two-Way handedly, vector algorithms
+also usually have pathological or edge cases that are better handled by Two-Way.
+Moreover, not all targets support vector algorithms or implementations for them
+simply may not exist yet.
+
+Two-Way can be found in the `memmem` implementations in at least [GNU libc] and
+[musl].
+
+[two-way]: https://en.wikipedia.org/wiki/Two-way_string-matching_algorithm
+[GNU libc]: https://www.gnu.org/software/libc/
+[musl]: https://www.musl-libc.org/
+*/
+
+use core::cmp;
+
+use crate::{
+    arch::all::{is_prefix, is_suffix},
+    memmem::Pre,
+};
+
+/// A forward substring searcher that uses the Two-Way algorithm.
+#[derive(Clone, Copy, Debug)]
+pub struct Finder(TwoWay);
+
+/// A reverse substring searcher that uses the Two-Way algorithm.
+#[derive(Clone, Copy, Debug)]
+pub struct FinderRev(TwoWay);
+
+/// An implementation of the TwoWay substring search algorithm.
+///
+/// This searcher supports forward and reverse search, although not
+/// simultaneously. It runs in `O(n + m)` time and `O(1)` space, where
+/// `n ~ len(needle)` and `m ~ len(haystack)`.
+///
+/// The implementation here roughly matches that which was developed by
+/// Crochemore and Perrin in their 1991 paper "Two-way string-matching." The
+/// changes in this implementation are 1) the use of zero-based indices, 2) a
+/// heuristic skip table based on the last byte (borrowed from Rust's standard
+/// library) and 3) the addition of heuristics for a fast skip loop. For (3),
+/// callers can pass any kind of prefilter they want, but usually it's one
+/// based on a heuristic that uses an approximate background frequency of bytes
+/// to choose rare bytes to quickly look for candidate match positions. Note
+/// though that currently, this prefilter functionality is not exposed directly
+/// in the public API. (File an issue if you want it and provide a use case
+/// please.)
+///
+/// The heuristic for fast skipping is automatically shut off if it's
+/// detected to be ineffective at search time. Generally, this only occurs in
+/// pathological cases. But this is generally necessary in order to preserve
+/// a `O(n + m)` time bound.
+///
+/// The code below is fairly complex and not obviously correct at all. It's
+/// likely necessary to read the Two-Way paper cited above in order to fully
+/// grok this code. The essence of it is:
+///
+/// 1. Do something to detect a "critical" position in the needle.
+/// 2. For the current position in the haystack, look if `needle[critical..]`
+/// matches at that position.
+/// 3. If so, look if `needle[..critical]` matches.
+/// 4. If a mismatch occurs, shift the search by some amount based on the
+/// critical position and a pre-computed shift.
+///
+/// This type is wrapped in the forward and reverse finders that expose
+/// consistent forward or reverse APIs.
+#[derive(Clone, Copy, Debug)]
+struct TwoWay {
+    /// A small bitset used as a quick prefilter (in addition to any prefilter
+    /// given by the caller). Namely, a bit `i` is set if and only if `b%64==i`
+    /// for any `b == needle[i]`.
+    ///
+    /// When used as a prefilter, if the last byte at the current candidate
+    /// position is NOT in this set, then we can skip that entire candidate
+    /// position (the length of the needle). This is essentially the shift
+    /// trick found in Boyer-Moore, but only applied to bytes that don't appear
+    /// in the needle.
+    ///
+    /// N.B. This trick was inspired by something similar in std's
+    /// implementation of Two-Way.
+    byteset: ApproximateByteSet,
+    /// A critical position in needle. Specifically, this position corresponds
+    /// to beginning of either the minimal or maximal suffix in needle. (N.B.
+    /// See SuffixType below for why "minimal" isn't quite the correct word
+    /// here.)
+    ///
+    /// This is the position at which every search begins. Namely, search
+    /// starts by scanning text to the right of this position, and only if
+    /// there's a match does the text to the left of this position get scanned.
+    critical_pos: usize,
+    /// The amount we shift by in the Two-Way search algorithm. This
+    /// corresponds to the "small period" and "large period" cases.
+    shift: Shift,
+}
+
+impl Finder {
+    /// Create a searcher that finds occurrences of the given `needle`.
+    ///
+    /// An empty `needle` results in a match at every position in a haystack,
+    /// including at `haystack.len()`.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Finder {
+        let byteset = ApproximateByteSet::new(needle);
+        let min_suffix = Suffix::forward(needle, SuffixKind::Minimal);
+        let max_suffix = Suffix::forward(needle, SuffixKind::Maximal);
+        let (period_lower_bound, critical_pos) =
+            if min_suffix.pos > max_suffix.pos {
+                (min_suffix.period, min_suffix.pos)
+            } else {
+                (max_suffix.period, max_suffix.pos)
+            };
+        let shift = Shift::forward(needle, period_lower_bound, critical_pos);
+        Finder(TwoWay { byteset, critical_pos, shift })
+    }
+
+    /// Returns the first occurrence of `needle` in the given `haystack`, or
+    /// `None` if no such occurrence could be found.
+    ///
+    /// The `needle` given must be the same as the `needle` provided to
+    /// [`Finder::new`].
+    ///
+    /// An empty `needle` results in a match at every position in a haystack,
+    /// including at `haystack.len()`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        self.find_with_prefilter(None, haystack, needle)
+    }
+
+    /// This is like [`Finder::find`], but it accepts a prefilter for
+    /// accelerating searches.
+    ///
+    /// Currently this is not exposed in the public API because, at the time
+    /// of writing, I didn't want to spend time thinking about how to expose
+    /// the prefilter infrastructure (if at all). If you have a compelling use
+    /// case for exposing this routine, please create an issue. Do *not* open
+    /// a PR that just exposes `Pre` and friends. Exporting this routine will
+    /// require API design.
+    #[inline(always)]
+    pub(crate) fn find_with_prefilter(
+        &self,
+        pre: Option<Pre<'_>>,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        match self.0.shift {
+            Shift::Small { period } => {
+                self.find_small_imp(pre, haystack, needle, period)
+            }
+            Shift::Large { shift } => {
+                self.find_large_imp(pre, haystack, needle, shift)
+            }
+        }
+    }
+
+    // Each of the two search implementations below can be accelerated by a
+    // prefilter, but it is not always enabled. To avoid its overhead when
+    // its disabled, we explicitly inline each search implementation based on
+    // whether a prefilter will be used or not. The decision on which to use
+    // is made in the parent meta searcher.
+
+    #[inline(always)]
+    fn find_small_imp(
+        &self,
+        mut pre: Option<Pre<'_>>,
+        haystack: &[u8],
+        needle: &[u8],
+        period: usize,
+    ) -> Option<usize> {
+        let mut pos = 0;
+        let mut shift = 0;
+        let last_byte_pos = match needle.len().checked_sub(1) {
+            None => return Some(pos),
+            Some(last_byte) => last_byte,
+        };
+        while pos + needle.len() <= haystack.len() {
+            let mut i = cmp::max(self.0.critical_pos, shift);
+            if let Some(pre) = pre.as_mut() {
+                if pre.is_effective() {
+                    pos += pre.find(&haystack[pos..])?;
+                    shift = 0;
+                    i = self.0.critical_pos;
+                    if pos + needle.len() > haystack.len() {
+                        return None;
+                    }
+                }
+            }
+            if !self.0.byteset.contains(haystack[pos + last_byte_pos]) {
+                pos += needle.len();
+                shift = 0;
+                continue;
+            }
+            while i < needle.len() && needle[i] == haystack[pos + i] {
+                i += 1;
+            }
+            if i < needle.len() {
+                pos += i - self.0.critical_pos + 1;
+                shift = 0;
+            } else {
+                let mut j = self.0.critical_pos;
+                while j > shift && needle[j] == haystack[pos + j] {
+                    j -= 1;
+                }
+                if j <= shift && needle[shift] == haystack[pos + shift] {
+                    return Some(pos);
+                }
+                pos += period;
+                shift = needle.len() - period;
+            }
+        }
+        None
+    }
+
+    #[inline(always)]
+    fn find_large_imp(
+        &self,
+        mut pre: Option<Pre<'_>>,
+        haystack: &[u8],
+        needle: &[u8],
+        shift: usize,
+    ) -> Option<usize> {
+        let mut pos = 0;
+        let last_byte_pos = match needle.len().checked_sub(1) {
+            None => return Some(pos),
+            Some(last_byte) => last_byte,
+        };
+        'outer: while pos + needle.len() <= haystack.len() {
+            if let Some(pre) = pre.as_mut() {
+                if pre.is_effective() {
+                    pos += pre.find(&haystack[pos..])?;
+                    if pos + needle.len() > haystack.len() {
+                        return None;
+                    }
+                }
+            }
+
+            if !self.0.byteset.contains(haystack[pos + last_byte_pos]) {
+                pos += needle.len();
+                continue;
+            }
+            let mut i = self.0.critical_pos;
+            while i < needle.len() && needle[i] == haystack[pos + i] {
+                i += 1;
+            }
+            if i < needle.len() {
+                pos += i - self.0.critical_pos + 1;
+            } else {
+                for j in (0..self.0.critical_pos).rev() {
+                    if needle[j] != haystack[pos + j] {
+                        pos += shift;
+                        continue 'outer;
+                    }
+                }
+                return Some(pos);
+            }
+        }
+        None
+    }
+}
+
+impl FinderRev {
+    /// Create a searcher that finds occurrences of the given `needle`.
+    ///
+    /// An empty `needle` results in a match at every position in a haystack,
+    /// including at `haystack.len()`.
+    #[inline]
+    pub fn new(needle: &[u8]) -> FinderRev {
+        let byteset = ApproximateByteSet::new(needle);
+        let min_suffix = Suffix::reverse(needle, SuffixKind::Minimal);
+        let max_suffix = Suffix::reverse(needle, SuffixKind::Maximal);
+        let (period_lower_bound, critical_pos) =
+            if min_suffix.pos < max_suffix.pos {
+                (min_suffix.period, min_suffix.pos)
+            } else {
+                (max_suffix.period, max_suffix.pos)
+            };
+        let shift = Shift::reverse(needle, period_lower_bound, critical_pos);
+        FinderRev(TwoWay { byteset, critical_pos, shift })
+    }
+
+    /// Returns the last occurrence of `needle` in the given `haystack`, or
+    /// `None` if no such occurrence could be found.
+    ///
+    /// The `needle` given must be the same as the `needle` provided to
+    /// [`FinderRev::new`].
+    ///
+    /// An empty `needle` results in a match at every position in a haystack,
+    /// including at `haystack.len()`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        // For the reverse case, we don't use a prefilter. It's plausible that
+        // perhaps we should, but it's a lot of additional code to do it, and
+        // it's not clear that it's actually worth it. If you have a really
+        // compelling use case for this, please file an issue.
+        match self.0.shift {
+            Shift::Small { period } => {
+                self.rfind_small_imp(haystack, needle, period)
+            }
+            Shift::Large { shift } => {
+                self.rfind_large_imp(haystack, needle, shift)
+            }
+        }
+    }
+
+    #[inline(always)]
+    fn rfind_small_imp(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+        period: usize,
+    ) -> Option<usize> {
+        let nlen = needle.len();
+        let mut pos = haystack.len();
+        let mut shift = nlen;
+        let first_byte = match needle.get(0) {
+            None => return Some(pos),
+            Some(&first_byte) => first_byte,
+        };
+        while pos >= nlen {
+            if !self.0.byteset.contains(haystack[pos - nlen]) {
+                pos -= nlen;
+                shift = nlen;
+                continue;
+            }
+            let mut i = cmp::min(self.0.critical_pos, shift);
+            while i > 0 && needle[i - 1] == haystack[pos - nlen + i - 1] {
+                i -= 1;
+            }
+            if i > 0 || first_byte != haystack[pos - nlen] {
+                pos -= self.0.critical_pos - i + 1;
+                shift = nlen;
+            } else {
+                let mut j = self.0.critical_pos;
+                while j < shift && needle[j] == haystack[pos - nlen + j] {
+                    j += 1;
+                }
+                if j >= shift {
+                    return Some(pos - nlen);
+                }
+                pos -= period;
+                shift = period;
+            }
+        }
+        None
+    }
+
+    #[inline(always)]
+    fn rfind_large_imp(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+        shift: usize,
+    ) -> Option<usize> {
+        let nlen = needle.len();
+        let mut pos = haystack.len();
+        let first_byte = match needle.get(0) {
+            None => return Some(pos),
+            Some(&first_byte) => first_byte,
+        };
+        while pos >= nlen {
+            if !self.0.byteset.contains(haystack[pos - nlen]) {
+                pos -= nlen;
+                continue;
+            }
+            let mut i = self.0.critical_pos;
+            while i > 0 && needle[i - 1] == haystack[pos - nlen + i - 1] {
+                i -= 1;
+            }
+            if i > 0 || first_byte != haystack[pos - nlen] {
+                pos -= self.0.critical_pos - i + 1;
+            } else {
+                let mut j = self.0.critical_pos;
+                while j < nlen && needle[j] == haystack[pos - nlen + j] {
+                    j += 1;
+                }
+                if j == nlen {
+                    return Some(pos - nlen);
+                }
+                pos -= shift;
+            }
+        }
+        None
+    }
+}
+
+/// A representation of the amount we're allowed to shift by during Two-Way
+/// search.
+///
+/// When computing a critical factorization of the needle, we find the position
+/// of the critical factorization by finding the needle's maximal (or minimal)
+/// suffix, along with the period of that suffix. It turns out that the period
+/// of that suffix is a lower bound on the period of the needle itself.
+///
+/// This lower bound is equivalent to the actual period of the needle in
+/// some cases. To describe that case, we denote the needle as `x` where
+/// `x = uv` and `v` is the lexicographic maximal suffix of `v`. The lower
+/// bound given here is always the period of `v`, which is `<= period(x)`. The
+/// case where `period(v) == period(x)` occurs when `len(u) < (len(x) / 2)` and
+/// where `u` is a suffix of `v[0..period(v)]`.
+///
+/// This case is important because the search algorithm for when the
+/// periods are equivalent is slightly different than the search algorithm
+/// for when the periods are not equivalent. In particular, when they aren't
+/// equivalent, we know that the period of the needle is no less than half its
+/// length. In this case, we shift by an amount less than or equal to the
+/// period of the needle (determined by the maximum length of the components
+/// of the critical factorization of `x`, i.e., `max(len(u), len(v))`)..
+///
+/// The above two cases are represented by the variants below. Each entails
+/// a different instantiation of the Two-Way search algorithm.
+///
+/// N.B. If we could find a way to compute the exact period in all cases,
+/// then we could collapse this case analysis and simplify the algorithm. The
+/// Two-Way paper suggests this is possible, but more reading is required to
+/// grok why the authors didn't pursue that path.
+#[derive(Clone, Copy, Debug)]
+enum Shift {
+    Small { period: usize },
+    Large { shift: usize },
+}
+
+impl Shift {
+    /// Compute the shift for a given needle in the forward direction.
+    ///
+    /// This requires a lower bound on the period and a critical position.
+    /// These can be computed by extracting both the minimal and maximal
+    /// lexicographic suffixes, and choosing the right-most starting position.
+    /// The lower bound on the period is then the period of the chosen suffix.
+    fn forward(
+        needle: &[u8],
+        period_lower_bound: usize,
+        critical_pos: usize,
+    ) -> Shift {
+        let large = cmp::max(critical_pos, needle.len() - critical_pos);
+        if critical_pos * 2 >= needle.len() {
+            return Shift::Large { shift: large };
+        }
+
+        let (u, v) = needle.split_at(critical_pos);
+        if !is_suffix(&v[..period_lower_bound], u) {
+            return Shift::Large { shift: large };
+        }
+        Shift::Small { period: period_lower_bound }
+    }
+
+    /// Compute the shift for a given needle in the reverse direction.
+    ///
+    /// This requires a lower bound on the period and a critical position.
+    /// These can be computed by extracting both the minimal and maximal
+    /// lexicographic suffixes, and choosing the left-most starting position.
+    /// The lower bound on the period is then the period of the chosen suffix.
+    fn reverse(
+        needle: &[u8],
+        period_lower_bound: usize,
+        critical_pos: usize,
+    ) -> Shift {
+        let large = cmp::max(critical_pos, needle.len() - critical_pos);
+        if (needle.len() - critical_pos) * 2 >= needle.len() {
+            return Shift::Large { shift: large };
+        }
+
+        let (v, u) = needle.split_at(critical_pos);
+        if !is_prefix(&v[v.len() - period_lower_bound..], u) {
+            return Shift::Large { shift: large };
+        }
+        Shift::Small { period: period_lower_bound }
+    }
+}
+
+/// A suffix extracted from a needle along with its period.
+#[derive(Debug)]
+struct Suffix {
+    /// The starting position of this suffix.
+    ///
+    /// If this is a forward suffix, then `&bytes[pos..]` can be used. If this
+    /// is a reverse suffix, then `&bytes[..pos]` can be used. That is, for
+    /// forward suffixes, this is an inclusive starting position, where as for
+    /// reverse suffixes, this is an exclusive ending position.
+    pos: usize,
+    /// The period of this suffix.
+    ///
+    /// Note that this is NOT necessarily the period of the string from which
+    /// this suffix comes from. (It is always less than or equal to the period
+    /// of the original string.)
+    period: usize,
+}
+
+impl Suffix {
+    fn forward(needle: &[u8], kind: SuffixKind) -> Suffix {
+        // suffix represents our maximal (or minimal) suffix, along with
+        // its period.
+        let mut suffix = Suffix { pos: 0, period: 1 };
+        // The start of a suffix in `needle` that we are considering as a
+        // more maximal (or minimal) suffix than what's in `suffix`.
+        let mut candidate_start = 1;
+        // The current offset of our suffixes that we're comparing.
+        //
+        // When the characters at this offset are the same, then we mush on
+        // to the next position since no decision is possible. When the
+        // candidate's character is greater (or lesser) than the corresponding
+        // character than our current maximal (or minimal) suffix, then the
+        // current suffix is changed over to the candidate and we restart our
+        // search. Otherwise, the candidate suffix is no good and we restart
+        // our search on the next candidate.
+        //
+        // The three cases above correspond to the three cases in the loop
+        // below.
+        let mut offset = 0;
+
+        while candidate_start + offset < needle.len() {
+            let current = needle[suffix.pos + offset];
+            let candidate = needle[candidate_start + offset];
+            match kind.cmp(current, candidate) {
+                SuffixOrdering::Accept => {
+                    suffix = Suffix { pos: candidate_start, period: 1 };
+                    candidate_start += 1;
+                    offset = 0;
+                }
+                SuffixOrdering::Skip => {
+                    candidate_start += offset + 1;
+                    offset = 0;
+                    suffix.period = candidate_start - suffix.pos;
+                }
+                SuffixOrdering::Push => {
+                    if offset + 1 == suffix.period {
+                        candidate_start += suffix.period;
+                        offset = 0;
+                    } else {
+                        offset += 1;
+                    }
+                }
+            }
+        }
+        suffix
+    }
+
+    fn reverse(needle: &[u8], kind: SuffixKind) -> Suffix {
+        // See the comments in `forward` for how this works.
+        let mut suffix = Suffix { pos: needle.len(), period: 1 };
+        if needle.len() == 1 {
+            return suffix;
+        }
+        let mut candidate_start = match needle.len().checked_sub(1) {
+            None => return suffix,
+            Some(candidate_start) => candidate_start,
+        };
+        let mut offset = 0;
+
+        while offset < candidate_start {
+            let current = needle[suffix.pos - offset - 1];
+            let candidate = needle[candidate_start - offset - 1];
+            match kind.cmp(current, candidate) {
+                SuffixOrdering::Accept => {
+                    suffix = Suffix { pos: candidate_start, period: 1 };
+                    candidate_start -= 1;
+                    offset = 0;
+                }
+                SuffixOrdering::Skip => {
+                    candidate_start -= offset + 1;
+                    offset = 0;
+                    suffix.period = suffix.pos - candidate_start;
+                }
+                SuffixOrdering::Push => {
+                    if offset + 1 == suffix.period {
+                        candidate_start -= suffix.period;
+                        offset = 0;
+                    } else {
+                        offset += 1;
+                    }
+                }
+            }
+        }
+        suffix
+    }
+}
+
+/// The kind of suffix to extract.
+#[derive(Clone, Copy, Debug)]
+enum SuffixKind {
+    /// Extract the smallest lexicographic suffix from a string.
+    ///
+    /// Technically, this doesn't actually pick the smallest lexicographic
+    /// suffix. e.g., Given the choice between `a` and `aa`, this will choose
+    /// the latter over the former, even though `a < aa`. The reasoning for
+    /// this isn't clear from the paper, but it still smells like a minimal
+    /// suffix.
+    Minimal,
+    /// Extract the largest lexicographic suffix from a string.
+    ///
+    /// Unlike `Minimal`, this really does pick the maximum suffix. e.g., Given
+    /// the choice between `z` and `zz`, this will choose the latter over the
+    /// former.
+    Maximal,
+}
+
+/// The result of comparing corresponding bytes between two suffixes.
+#[derive(Clone, Copy, Debug)]
+enum SuffixOrdering {
+    /// This occurs when the given candidate byte indicates that the candidate
+    /// suffix is better than the current maximal (or minimal) suffix. That is,
+    /// the current candidate suffix should supplant the current maximal (or
+    /// minimal) suffix.
+    Accept,
+    /// This occurs when the given candidate byte excludes the candidate suffix
+    /// from being better than the current maximal (or minimal) suffix. That
+    /// is, the current candidate suffix should be dropped and the next one
+    /// should be considered.
+    Skip,
+    /// This occurs when no decision to accept or skip the candidate suffix
+    /// can be made, e.g., when corresponding bytes are equivalent. In this
+    /// case, the next corresponding bytes should be compared.
+    Push,
+}
+
+impl SuffixKind {
+    /// Returns true if and only if the given candidate byte indicates that
+    /// it should replace the current suffix as the maximal (or minimal)
+    /// suffix.
+    fn cmp(self, current: u8, candidate: u8) -> SuffixOrdering {
+        use self::SuffixOrdering::*;
+
+        match self {
+            SuffixKind::Minimal if candidate < current => Accept,
+            SuffixKind::Minimal if candidate > current => Skip,
+            SuffixKind::Minimal => Push,
+            SuffixKind::Maximal if candidate > current => Accept,
+            SuffixKind::Maximal if candidate < current => Skip,
+            SuffixKind::Maximal => Push,
+        }
+    }
+}
+
+/// A bitset used to track whether a particular byte exists in a needle or not.
+///
+/// Namely, bit 'i' is set if and only if byte%64==i for any byte in the
+/// needle. If a particular byte in the haystack is NOT in this set, then one
+/// can conclude that it is also not in the needle, and thus, one can advance
+/// in the haystack by needle.len() bytes.
+#[derive(Clone, Copy, Debug)]
+struct ApproximateByteSet(u64);
+
+impl ApproximateByteSet {
+    /// Create a new set from the given needle.
+    fn new(needle: &[u8]) -> ApproximateByteSet {
+        let mut bits = 0;
+        for &b in needle {
+            bits |= 1 << (b % 64);
+        }
+        ApproximateByteSet(bits)
+    }
+
+    /// Return true if and only if the given byte might be in this set. This
+    /// may return a false positive, but will never return a false negative.
+    #[inline(always)]
+    fn contains(&self, byte: u8) -> bool {
+        self.0 & (1 << (byte % 64)) != 0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use alloc::vec::Vec;
+
+    use super::*;
+
+    /// Convenience wrapper for computing the suffix as a byte string.
+    fn get_suffix_forward(needle: &[u8], kind: SuffixKind) -> (&[u8], usize) {
+        let s = Suffix::forward(needle, kind);
+        (&needle[s.pos..], s.period)
+    }
+
+    /// Convenience wrapper for computing the reverse suffix as a byte string.
+    fn get_suffix_reverse(needle: &[u8], kind: SuffixKind) -> (&[u8], usize) {
+        let s = Suffix::reverse(needle, kind);
+        (&needle[..s.pos], s.period)
+    }
+
+    /// Return all of the non-empty suffixes in the given byte string.
+    fn suffixes(bytes: &[u8]) -> Vec<&[u8]> {
+        (0..bytes.len()).map(|i| &bytes[i..]).collect()
+    }
+
+    /// Return the lexicographically maximal suffix of the given byte string.
+    fn naive_maximal_suffix_forward(needle: &[u8]) -> &[u8] {
+        let mut sufs = suffixes(needle);
+        sufs.sort();
+        sufs.pop().unwrap()
+    }
+
+    /// Return the lexicographically maximal suffix of the reverse of the given
+    /// byte string.
+    fn naive_maximal_suffix_reverse(needle: &[u8]) -> Vec<u8> {
+        let mut reversed = needle.to_vec();
+        reversed.reverse();
+        let mut got = naive_maximal_suffix_forward(&reversed).to_vec();
+        got.reverse();
+        got
+    }
+
+    define_substring_forward_quickcheck!(|h, n| Some(
+        Finder::new(n).find(h, n)
+    ));
+    define_substring_reverse_quickcheck!(|h, n| Some(
+        FinderRev::new(n).rfind(h, n)
+    ));
+
+    #[test]
+    fn forward() {
+        crate::tests::substring::Runner::new()
+            .fwd(|h, n| Some(Finder::new(n).find(h, n)))
+            .run();
+    }
+
+    #[test]
+    fn reverse() {
+        crate::tests::substring::Runner::new()
+            .rev(|h, n| Some(FinderRev::new(n).rfind(h, n)))
+            .run();
+    }
+
+    #[test]
+    fn suffix_forward() {
+        macro_rules! assert_suffix_min {
+            ($given:expr, $expected:expr, $period:expr) => {
+                let (got_suffix, got_period) =
+                    get_suffix_forward($given.as_bytes(), SuffixKind::Minimal);
+                let got_suffix = core::str::from_utf8(got_suffix).unwrap();
+                assert_eq!(($expected, $period), (got_suffix, got_period));
+            };
+        }
+
+        macro_rules! assert_suffix_max {
+            ($given:expr, $expected:expr, $period:expr) => {
+                let (got_suffix, got_period) =
+                    get_suffix_forward($given.as_bytes(), SuffixKind::Maximal);
+                let got_suffix = core::str::from_utf8(got_suffix).unwrap();
+                assert_eq!(($expected, $period), (got_suffix, got_period));
+            };
+        }
+
+        assert_suffix_min!("a", "a", 1);
+        assert_suffix_max!("a", "a", 1);
+
+        assert_suffix_min!("ab", "ab", 2);
+        assert_suffix_max!("ab", "b", 1);
+
+        assert_suffix_min!("ba", "a", 1);
+        assert_suffix_max!("ba", "ba", 2);
+
+        assert_suffix_min!("abc", "abc", 3);
+        assert_suffix_max!("abc", "c", 1);
+
+        assert_suffix_min!("acb", "acb", 3);
+        assert_suffix_max!("acb", "cb", 2);
+
+        assert_suffix_min!("cba", "a", 1);
+        assert_suffix_max!("cba", "cba", 3);
+
+        assert_suffix_min!("abcabc", "abcabc", 3);
+        assert_suffix_max!("abcabc", "cabc", 3);
+
+        assert_suffix_min!("abcabcabc", "abcabcabc", 3);
+        assert_suffix_max!("abcabcabc", "cabcabc", 3);
+
+        assert_suffix_min!("abczz", "abczz", 5);
+        assert_suffix_max!("abczz", "zz", 1);
+
+        assert_suffix_min!("zzabc", "abc", 3);
+        assert_suffix_max!("zzabc", "zzabc", 5);
+
+        assert_suffix_min!("aaa", "aaa", 1);
+        assert_suffix_max!("aaa", "aaa", 1);
+
+        assert_suffix_min!("foobar", "ar", 2);
+        assert_suffix_max!("foobar", "r", 1);
+    }
+
+    #[test]
+    fn suffix_reverse() {
+        macro_rules! assert_suffix_min {
+            ($given:expr, $expected:expr, $period:expr) => {
+                let (got_suffix, got_period) =
+                    get_suffix_reverse($given.as_bytes(), SuffixKind::Minimal);
+                let got_suffix = core::str::from_utf8(got_suffix).unwrap();
+                assert_eq!(($expected, $period), (got_suffix, got_period));
+            };
+        }
+
+        macro_rules! assert_suffix_max {
+            ($given:expr, $expected:expr, $period:expr) => {
+                let (got_suffix, got_period) =
+                    get_suffix_reverse($given.as_bytes(), SuffixKind::Maximal);
+                let got_suffix = core::str::from_utf8(got_suffix).unwrap();
+                assert_eq!(($expected, $period), (got_suffix, got_period));
+            };
+        }
+
+        assert_suffix_min!("a", "a", 1);
+        assert_suffix_max!("a", "a", 1);
+
+        assert_suffix_min!("ab", "a", 1);
+        assert_suffix_max!("ab", "ab", 2);
+
+        assert_suffix_min!("ba", "ba", 2);
+        assert_suffix_max!("ba", "b", 1);
+
+        assert_suffix_min!("abc", "a", 1);
+        assert_suffix_max!("abc", "abc", 3);
+
+        assert_suffix_min!("acb", "a", 1);
+        assert_suffix_max!("acb", "ac", 2);
+
+        assert_suffix_min!("cba", "cba", 3);
+        assert_suffix_max!("cba", "c", 1);
+
+        assert_suffix_min!("abcabc", "abca", 3);
+        assert_suffix_max!("abcabc", "abcabc", 3);
+
+        assert_suffix_min!("abcabcabc", "abcabca", 3);
+        assert_suffix_max!("abcabcabc", "abcabcabc", 3);
+
+        assert_suffix_min!("abczz", "a", 1);
+        assert_suffix_max!("abczz", "abczz", 5);
+
+        assert_suffix_min!("zzabc", "zza", 3);
+        assert_suffix_max!("zzabc", "zz", 1);
+
+        assert_suffix_min!("aaa", "aaa", 1);
+        assert_suffix_max!("aaa", "aaa", 1);
+    }
+
+    #[cfg(not(miri))]
+    quickcheck::quickcheck! {
+        fn qc_suffix_forward_maximal(bytes: Vec<u8>) -> bool {
+            if bytes.is_empty() {
+                return true;
+            }
+
+            let (got, _) = get_suffix_forward(&bytes, SuffixKind::Maximal);
+            let expected = naive_maximal_suffix_forward(&bytes);
+            got == expected
+        }
+
+        fn qc_suffix_reverse_maximal(bytes: Vec<u8>) -> bool {
+            if bytes.is_empty() {
+                return true;
+            }
+
+            let (got, _) = get_suffix_reverse(&bytes, SuffixKind::Maximal);
+            let expected = naive_maximal_suffix_reverse(&bytes);
+            expected == got
+        }
+    }
+
+    // This is a regression test caught by quickcheck that exercised a bug in
+    // the reverse small period handling. The bug was that we were using 'if j
+    // == shift' to determine if a match occurred, but the correct guard is 'if
+    // j >= shift', which matches the corresponding guard in the forward impl.
+    #[test]
+    fn regression_rev_small_period() {
+        let rfind = |h, n| FinderRev::new(n).rfind(h, n);
+        let haystack = "ababaz";
+        let needle = "abab";
+        assert_eq!(Some(0), rfind(haystack.as_bytes(), needle.as_bytes()));
+    }
+}
diff --git a/vendor/memchr/src/arch/generic/memchr.rs b/vendor/memchr/src/arch/generic/memchr.rs
new file mode 100644
index 0000000..580b3cc
--- /dev/null
+++ b/vendor/memchr/src/arch/generic/memchr.rs
@@ -0,0 +1,1214 @@
+/*!
+Generic crate-internal routines for the `memchr` family of functions.
+*/
+
+// What follows is a vector algorithm generic over the specific vector
+// type to detect the position of one, two or three needles in a haystack.
+// From what I know, this is a "classic" algorithm, although I don't
+// believe it has been published in any peer reviewed journal. I believe
+// it can be found in places like glibc and Go's standard library. It
+// appears to be well known and is elaborated on in more detail here:
+// https://gms.tf/stdfind-and-memchr-optimizations.html
+//
+// While the routine below is fairly long and perhaps intimidating, the basic
+// idea is actually very simple and can be expressed straight-forwardly in
+// pseudo code. The psuedo code below is written for 128 bit vectors, but the
+// actual code below works for anything that implements the Vector trait.
+//
+//     needle = (n1 << 15) | (n1 << 14) | ... | (n1 << 1) | n1
+//     // Note: shift amount is in bytes
+//
+//     while i <= haystack.len() - 16:
+//       // A 16 byte vector. Each byte in chunk corresponds to a byte in
+//       // the haystack.
+//       chunk = haystack[i:i+16]
+//       // Compare bytes in needle with bytes in chunk. The result is a 16
+//       // byte chunk where each byte is 0xFF if the corresponding bytes
+//       // in needle and chunk were equal, or 0x00 otherwise.
+//       eqs = cmpeq(needle, chunk)
+//       // Return a 32 bit integer where the most significant 16 bits
+//       // are always 0 and the lower 16 bits correspond to whether the
+//       // most significant bit in the correspond byte in `eqs` is set.
+//       // In other words, `mask as u16` has bit i set if and only if
+//       // needle[i] == chunk[i].
+//       mask = movemask(eqs)
+//
+//       // Mask is 0 if there is no match, and non-zero otherwise.
+//       if mask != 0:
+//         // trailing_zeros tells us the position of the least significant
+//         // bit that is set.
+//         return i + trailing_zeros(mask)
+//
+//     // haystack length may not be a multiple of 16, so search the rest.
+//     while i < haystack.len():
+//       if haystack[i] == n1:
+//         return i
+//
+//     // No match found.
+//     return NULL
+//
+// In fact, we could loosely translate the above code to Rust line-for-line
+// and it would be a pretty fast algorithm. But, we pull out all the stops
+// to go as fast as possible:
+//
+// 1. We use aligned loads. That is, we do some finagling to make sure our
+//    primary loop not only proceeds in increments of 16 bytes, but that
+//    the address of haystack's pointer that we dereference is aligned to
+//    16 bytes. 16 is a magic number here because it is the size of SSE2
+//    128-bit vector. (For the AVX2 algorithm, 32 is the magic number.)
+//    Therefore, to get aligned loads, our pointer's address must be evenly
+//    divisible by 16.
+// 2. Our primary loop proceeds 64 bytes at a time instead of 16. It's
+//    kind of like loop unrolling, but we combine the equality comparisons
+//    using a vector OR such that we only need to extract a single mask to
+//    determine whether a match exists or not. If so, then we do some
+//    book-keeping to determine the precise location but otherwise mush on.
+// 3. We use our "chunk" comparison routine in as many places as possible,
+//    even if it means using unaligned loads. In particular, if haystack
+//    starts with an unaligned address, then we do an unaligned load to
+//    search the first 16 bytes. We then start our primary loop at the
+//    smallest subsequent aligned address, which will actually overlap with
+//    previously searched bytes. But we're OK with that. We do a similar
+//    dance at the end of our primary loop. Finally, to avoid a
+//    byte-at-a-time loop at the end, we do a final 16 byte unaligned load
+//    that may overlap with a previous load. This is OK because it converts
+//    a loop into a small number of very fast vector instructions. The overlap
+//    is OK because we know the place where the overlap occurs does not
+//    contain a match.
+//
+// And that's pretty all there is to it. Note that since the below is
+// generic and since it's meant to be inlined into routines with a
+// `#[target_feature(enable = "...")]` annotation, we must mark all routines as
+// both unsafe and `#[inline(always)]`.
+//
+// The fact that the code below is generic does somewhat inhibit us. For
+// example, I've noticed that introducing an unlineable `#[cold]` function to
+// handle the match case in the loop generates tighter assembly, but there is
+// no way to do this in the generic code below because the generic code doesn't
+// know what `target_feature` annotation to apply to the unlineable function.
+// We could make such functions part of the `Vector` trait, but we instead live
+// with the slightly sub-optimal codegen for now since it doesn't seem to have
+// a noticeable perf difference.
+
+use crate::{
+    ext::Pointer,
+    vector::{MoveMask, Vector},
+};
+
+/// Finds all occurrences of a single byte in a haystack.
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct One<V> {
+    s1: u8,
+    v1: V,
+}
+
+impl<V: Vector> One<V> {
+    /// The number of bytes we examine per each iteration of our search loop.
+    const LOOP_SIZE: usize = 4 * V::BYTES;
+
+    /// Create a new searcher that finds occurrences of the byte given.
+    #[inline(always)]
+    pub(crate) unsafe fn new(needle: u8) -> One<V> {
+        One { s1: needle, v1: V::splat(needle) }
+    }
+
+    /// Returns the needle given to `One::new`.
+    #[inline(always)]
+    pub(crate) fn needle1(&self) -> u8 {
+        self.s1
+    }
+
+    /// Return a pointer to the first occurrence of the needle in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// # Safety
+    ///
+    /// * It must be the case that `start < end` and that the distance between
+    /// them is at least equal to `V::BYTES`. That is, it must always be valid
+    /// to do at least an unaligned load of `V` at `start`.
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    #[inline(always)]
+    pub(crate) unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        // If we want to support vectors bigger than 256 bits, we probably
+        // need to move up to using a u64 for the masks used below. Currently
+        // they are 32 bits, which means we're SOL for vectors that need masks
+        // bigger than 32 bits. Overall unclear until there's a use case.
+        debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes");
+
+        let topos = V::Mask::first_offset;
+        let len = end.distance(start);
+        debug_assert!(
+            len >= V::BYTES,
+            "haystack has length {}, but must be at least {}",
+            len,
+            V::BYTES
+        );
+
+        // Search a possibly unaligned chunk at `start`. This covers any part
+        // of the haystack prior to where aligned loads can start.
+        if let Some(cur) = self.search_chunk(start, topos) {
+            return Some(cur);
+        }
+        // Set `cur` to the first V-aligned pointer greater than `start`.
+        let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN));
+        debug_assert!(cur > start && end.sub(V::BYTES) >= start);
+        if len >= Self::LOOP_SIZE {
+            while cur <= end.sub(Self::LOOP_SIZE) {
+                debug_assert_eq!(0, cur.as_usize() % V::BYTES);
+
+                let a = V::load_aligned(cur);
+                let b = V::load_aligned(cur.add(1 * V::BYTES));
+                let c = V::load_aligned(cur.add(2 * V::BYTES));
+                let d = V::load_aligned(cur.add(3 * V::BYTES));
+                let eqa = self.v1.cmpeq(a);
+                let eqb = self.v1.cmpeq(b);
+                let eqc = self.v1.cmpeq(c);
+                let eqd = self.v1.cmpeq(d);
+                let or1 = eqa.or(eqb);
+                let or2 = eqc.or(eqd);
+                let or3 = or1.or(or2);
+                if or3.movemask_will_have_non_zero() {
+                    let mask = eqa.movemask();
+                    if mask.has_non_zero() {
+                        return Some(cur.add(topos(mask)));
+                    }
+
+                    let mask = eqb.movemask();
+                    if mask.has_non_zero() {
+                        return Some(cur.add(1 * V::BYTES).add(topos(mask)));
+                    }
+
+                    let mask = eqc.movemask();
+                    if mask.has_non_zero() {
+                        return Some(cur.add(2 * V::BYTES).add(topos(mask)));
+                    }
+
+                    let mask = eqd.movemask();
+                    debug_assert!(mask.has_non_zero());
+                    return Some(cur.add(3 * V::BYTES).add(topos(mask)));
+                }
+                cur = cur.add(Self::LOOP_SIZE);
+            }
+        }
+        // Handle any leftovers after the aligned loop above. We use unaligned
+        // loads here, but I believe we are guaranteed that they are aligned
+        // since `cur` is aligned.
+        while cur <= end.sub(V::BYTES) {
+            debug_assert!(end.distance(cur) >= V::BYTES);
+            if let Some(cur) = self.search_chunk(cur, topos) {
+                return Some(cur);
+            }
+            cur = cur.add(V::BYTES);
+        }
+        // Finally handle any remaining bytes less than the size of V. In this
+        // case, our pointer may indeed be unaligned and the load may overlap
+        // with the previous one. But that's okay since we know the previous
+        // load didn't lead to a match (otherwise we wouldn't be here).
+        if cur < end {
+            debug_assert!(end.distance(cur) < V::BYTES);
+            cur = cur.sub(V::BYTES - end.distance(cur));
+            debug_assert_eq!(end.distance(cur), V::BYTES);
+            return self.search_chunk(cur, topos);
+        }
+        None
+    }
+
+    /// Return a pointer to the last occurrence of the needle in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// # Safety
+    ///
+    /// * It must be the case that `start < end` and that the distance between
+    /// them is at least equal to `V::BYTES`. That is, it must always be valid
+    /// to do at least an unaligned load of `V` at `start`.
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    #[inline(always)]
+    pub(crate) unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        // If we want to support vectors bigger than 256 bits, we probably
+        // need to move up to using a u64 for the masks used below. Currently
+        // they are 32 bits, which means we're SOL for vectors that need masks
+        // bigger than 32 bits. Overall unclear until there's a use case.
+        debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes");
+
+        let topos = V::Mask::last_offset;
+        let len = end.distance(start);
+        debug_assert!(
+            len >= V::BYTES,
+            "haystack has length {}, but must be at least {}",
+            len,
+            V::BYTES
+        );
+
+        if let Some(cur) = self.search_chunk(end.sub(V::BYTES), topos) {
+            return Some(cur);
+        }
+        let mut cur = end.sub(end.as_usize() & V::ALIGN);
+        debug_assert!(start <= cur && cur <= end);
+        if len >= Self::LOOP_SIZE {
+            while cur >= start.add(Self::LOOP_SIZE) {
+                debug_assert_eq!(0, cur.as_usize() % V::BYTES);
+
+                cur = cur.sub(Self::LOOP_SIZE);
+                let a = V::load_aligned(cur);
+                let b = V::load_aligned(cur.add(1 * V::BYTES));
+                let c = V::load_aligned(cur.add(2 * V::BYTES));
+                let d = V::load_aligned(cur.add(3 * V::BYTES));
+                let eqa = self.v1.cmpeq(a);
+                let eqb = self.v1.cmpeq(b);
+                let eqc = self.v1.cmpeq(c);
+                let eqd = self.v1.cmpeq(d);
+                let or1 = eqa.or(eqb);
+                let or2 = eqc.or(eqd);
+                let or3 = or1.or(or2);
+                if or3.movemask_will_have_non_zero() {
+                    let mask = eqd.movemask();
+                    if mask.has_non_zero() {
+                        return Some(cur.add(3 * V::BYTES).add(topos(mask)));
+                    }
+
+                    let mask = eqc.movemask();
+                    if mask.has_non_zero() {
+                        return Some(cur.add(2 * V::BYTES).add(topos(mask)));
+                    }
+
+                    let mask = eqb.movemask();
+                    if mask.has_non_zero() {
+                        return Some(cur.add(1 * V::BYTES).add(topos(mask)));
+                    }
+
+                    let mask = eqa.movemask();
+                    debug_assert!(mask.has_non_zero());
+                    return Some(cur.add(topos(mask)));
+                }
+            }
+        }
+        while cur >= start.add(V::BYTES) {
+            debug_assert!(cur.distance(start) >= V::BYTES);
+            cur = cur.sub(V::BYTES);
+            if let Some(cur) = self.search_chunk(cur, topos) {
+                return Some(cur);
+            }
+        }
+        if cur > start {
+            debug_assert!(cur.distance(start) < V::BYTES);
+            return self.search_chunk(start, topos);
+        }
+        None
+    }
+
+    /// Return a count of all matching bytes in the given haystack.
+    ///
+    /// # Safety
+    ///
+    /// * It must be the case that `start < end` and that the distance between
+    /// them is at least equal to `V::BYTES`. That is, it must always be valid
+    /// to do at least an unaligned load of `V` at `start`.
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    #[inline(always)]
+    pub(crate) unsafe fn count_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> usize {
+        debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes");
+
+        let confirm = |b| b == self.needle1();
+        let len = end.distance(start);
+        debug_assert!(
+            len >= V::BYTES,
+            "haystack has length {}, but must be at least {}",
+            len,
+            V::BYTES
+        );
+
+        // Set `cur` to the first V-aligned pointer greater than `start`.
+        let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN));
+        // Count any matching bytes before we start our aligned loop.
+        let mut count = count_byte_by_byte(start, cur, confirm);
+        debug_assert!(cur > start && end.sub(V::BYTES) >= start);
+        if len >= Self::LOOP_SIZE {
+            while cur <= end.sub(Self::LOOP_SIZE) {
+                debug_assert_eq!(0, cur.as_usize() % V::BYTES);
+
+                let a = V::load_aligned(cur);
+                let b = V::load_aligned(cur.add(1 * V::BYTES));
+                let c = V::load_aligned(cur.add(2 * V::BYTES));
+                let d = V::load_aligned(cur.add(3 * V::BYTES));
+                let eqa = self.v1.cmpeq(a);
+                let eqb = self.v1.cmpeq(b);
+                let eqc = self.v1.cmpeq(c);
+                let eqd = self.v1.cmpeq(d);
+                count += eqa.movemask().count_ones();
+                count += eqb.movemask().count_ones();
+                count += eqc.movemask().count_ones();
+                count += eqd.movemask().count_ones();
+                cur = cur.add(Self::LOOP_SIZE);
+            }
+        }
+        // Handle any leftovers after the aligned loop above. We use unaligned
+        // loads here, but I believe we are guaranteed that they are aligned
+        // since `cur` is aligned.
+        while cur <= end.sub(V::BYTES) {
+            debug_assert!(end.distance(cur) >= V::BYTES);
+            let chunk = V::load_unaligned(cur);
+            count += self.v1.cmpeq(chunk).movemask().count_ones();
+            cur = cur.add(V::BYTES);
+        }
+        // And finally count any leftovers that weren't caught above.
+        count += count_byte_by_byte(cur, end, confirm);
+        count
+    }
+
+    /// Search `V::BYTES` starting at `cur` via an unaligned load.
+    ///
+    /// `mask_to_offset` should be a function that converts a `movemask` to
+    /// an offset such that `cur.add(offset)` corresponds to a pointer to the
+    /// match location if one is found. Generally it is expected to use either
+    /// `mask_to_first_offset` or `mask_to_last_offset`, depending on whether
+    /// one is implementing a forward or reverse search, respectively.
+    ///
+    /// # Safety
+    ///
+    /// `cur` must be a valid pointer and it must be valid to do an unaligned
+    /// load of size `V::BYTES` at `cur`.
+    #[inline(always)]
+    unsafe fn search_chunk(
+        &self,
+        cur: *const u8,
+        mask_to_offset: impl Fn(V::Mask) -> usize,
+    ) -> Option<*const u8> {
+        let chunk = V::load_unaligned(cur);
+        let mask = self.v1.cmpeq(chunk).movemask();
+        if mask.has_non_zero() {
+            Some(cur.add(mask_to_offset(mask)))
+        } else {
+            None
+        }
+    }
+}
+
+/// Finds all occurrences of two bytes in a haystack.
+///
+/// That is, this reports matches of one of two possible bytes. For example,
+/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`,
+/// `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct Two<V> {
+    s1: u8,
+    s2: u8,
+    v1: V,
+    v2: V,
+}
+
+impl<V: Vector> Two<V> {
+    /// The number of bytes we examine per each iteration of our search loop.
+    const LOOP_SIZE: usize = 2 * V::BYTES;
+
+    /// Create a new searcher that finds occurrences of the byte given.
+    #[inline(always)]
+    pub(crate) unsafe fn new(needle1: u8, needle2: u8) -> Two<V> {
+        Two {
+            s1: needle1,
+            s2: needle2,
+            v1: V::splat(needle1),
+            v2: V::splat(needle2),
+        }
+    }
+
+    /// Returns the first needle given to `Two::new`.
+    #[inline(always)]
+    pub(crate) fn needle1(&self) -> u8 {
+        self.s1
+    }
+
+    /// Returns the second needle given to `Two::new`.
+    #[inline(always)]
+    pub(crate) fn needle2(&self) -> u8 {
+        self.s2
+    }
+
+    /// Return a pointer to the first occurrence of one of the needles in the
+    /// given haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// # Safety
+    ///
+    /// * It must be the case that `start < end` and that the distance between
+    /// them is at least equal to `V::BYTES`. That is, it must always be valid
+    /// to do at least an unaligned load of `V` at `start`.
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    #[inline(always)]
+    pub(crate) unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        // If we want to support vectors bigger than 256 bits, we probably
+        // need to move up to using a u64 for the masks used below. Currently
+        // they are 32 bits, which means we're SOL for vectors that need masks
+        // bigger than 32 bits. Overall unclear until there's a use case.
+        debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes");
+
+        let topos = V::Mask::first_offset;
+        let len = end.distance(start);
+        debug_assert!(
+            len >= V::BYTES,
+            "haystack has length {}, but must be at least {}",
+            len,
+            V::BYTES
+        );
+
+        // Search a possibly unaligned chunk at `start`. This covers any part
+        // of the haystack prior to where aligned loads can start.
+        if let Some(cur) = self.search_chunk(start, topos) {
+            return Some(cur);
+        }
+        // Set `cur` to the first V-aligned pointer greater than `start`.
+        let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN));
+        debug_assert!(cur > start && end.sub(V::BYTES) >= start);
+        if len >= Self::LOOP_SIZE {
+            while cur <= end.sub(Self::LOOP_SIZE) {
+                debug_assert_eq!(0, cur.as_usize() % V::BYTES);
+
+                let a = V::load_aligned(cur);
+                let b = V::load_aligned(cur.add(V::BYTES));
+                let eqa1 = self.v1.cmpeq(a);
+                let eqb1 = self.v1.cmpeq(b);
+                let eqa2 = self.v2.cmpeq(a);
+                let eqb2 = self.v2.cmpeq(b);
+                let or1 = eqa1.or(eqb1);
+                let or2 = eqa2.or(eqb2);
+                let or3 = or1.or(or2);
+                if or3.movemask_will_have_non_zero() {
+                    let mask = eqa1.movemask().or(eqa2.movemask());
+                    if mask.has_non_zero() {
+                        return Some(cur.add(topos(mask)));
+                    }
+
+                    let mask = eqb1.movemask().or(eqb2.movemask());
+                    debug_assert!(mask.has_non_zero());
+                    return Some(cur.add(V::BYTES).add(topos(mask)));
+                }
+                cur = cur.add(Self::LOOP_SIZE);
+            }
+        }
+        // Handle any leftovers after the aligned loop above. We use unaligned
+        // loads here, but I believe we are guaranteed that they are aligned
+        // since `cur` is aligned.
+        while cur <= end.sub(V::BYTES) {
+            debug_assert!(end.distance(cur) >= V::BYTES);
+            if let Some(cur) = self.search_chunk(cur, topos) {
+                return Some(cur);
+            }
+            cur = cur.add(V::BYTES);
+        }
+        // Finally handle any remaining bytes less than the size of V. In this
+        // case, our pointer may indeed be unaligned and the load may overlap
+        // with the previous one. But that's okay since we know the previous
+        // load didn't lead to a match (otherwise we wouldn't be here).
+        if cur < end {
+            debug_assert!(end.distance(cur) < V::BYTES);
+            cur = cur.sub(V::BYTES - end.distance(cur));
+            debug_assert_eq!(end.distance(cur), V::BYTES);
+            return self.search_chunk(cur, topos);
+        }
+        None
+    }
+
+    /// Return a pointer to the last occurrence of the needle in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// # Safety
+    ///
+    /// * It must be the case that `start < end` and that the distance between
+    /// them is at least equal to `V::BYTES`. That is, it must always be valid
+    /// to do at least an unaligned load of `V` at `start`.
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    #[inline(always)]
+    pub(crate) unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        // If we want to support vectors bigger than 256 bits, we probably
+        // need to move up to using a u64 for the masks used below. Currently
+        // they are 32 bits, which means we're SOL for vectors that need masks
+        // bigger than 32 bits. Overall unclear until there's a use case.
+        debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes");
+
+        let topos = V::Mask::last_offset;
+        let len = end.distance(start);
+        debug_assert!(
+            len >= V::BYTES,
+            "haystack has length {}, but must be at least {}",
+            len,
+            V::BYTES
+        );
+
+        if let Some(cur) = self.search_chunk(end.sub(V::BYTES), topos) {
+            return Some(cur);
+        }
+        let mut cur = end.sub(end.as_usize() & V::ALIGN);
+        debug_assert!(start <= cur && cur <= end);
+        if len >= Self::LOOP_SIZE {
+            while cur >= start.add(Self::LOOP_SIZE) {
+                debug_assert_eq!(0, cur.as_usize() % V::BYTES);
+
+                cur = cur.sub(Self::LOOP_SIZE);
+                let a = V::load_aligned(cur);
+                let b = V::load_aligned(cur.add(V::BYTES));
+                let eqa1 = self.v1.cmpeq(a);
+                let eqb1 = self.v1.cmpeq(b);
+                let eqa2 = self.v2.cmpeq(a);
+                let eqb2 = self.v2.cmpeq(b);
+                let or1 = eqa1.or(eqb1);
+                let or2 = eqa2.or(eqb2);
+                let or3 = or1.or(or2);
+                if or3.movemask_will_have_non_zero() {
+                    let mask = eqb1.movemask().or(eqb2.movemask());
+                    if mask.has_non_zero() {
+                        return Some(cur.add(V::BYTES).add(topos(mask)));
+                    }
+
+                    let mask = eqa1.movemask().or(eqa2.movemask());
+                    debug_assert!(mask.has_non_zero());
+                    return Some(cur.add(topos(mask)));
+                }
+            }
+        }
+        while cur >= start.add(V::BYTES) {
+            debug_assert!(cur.distance(start) >= V::BYTES);
+            cur = cur.sub(V::BYTES);
+            if let Some(cur) = self.search_chunk(cur, topos) {
+                return Some(cur);
+            }
+        }
+        if cur > start {
+            debug_assert!(cur.distance(start) < V::BYTES);
+            return self.search_chunk(start, topos);
+        }
+        None
+    }
+
+    /// Search `V::BYTES` starting at `cur` via an unaligned load.
+    ///
+    /// `mask_to_offset` should be a function that converts a `movemask` to
+    /// an offset such that `cur.add(offset)` corresponds to a pointer to the
+    /// match location if one is found. Generally it is expected to use either
+    /// `mask_to_first_offset` or `mask_to_last_offset`, depending on whether
+    /// one is implementing a forward or reverse search, respectively.
+    ///
+    /// # Safety
+    ///
+    /// `cur` must be a valid pointer and it must be valid to do an unaligned
+    /// load of size `V::BYTES` at `cur`.
+    #[inline(always)]
+    unsafe fn search_chunk(
+        &self,
+        cur: *const u8,
+        mask_to_offset: impl Fn(V::Mask) -> usize,
+    ) -> Option<*const u8> {
+        let chunk = V::load_unaligned(cur);
+        let eq1 = self.v1.cmpeq(chunk);
+        let eq2 = self.v2.cmpeq(chunk);
+        let mask = eq1.or(eq2).movemask();
+        if mask.has_non_zero() {
+            let mask1 = eq1.movemask();
+            let mask2 = eq2.movemask();
+            Some(cur.add(mask_to_offset(mask1.or(mask2))))
+        } else {
+            None
+        }
+    }
+}
+
+/// Finds all occurrences of two bytes in a haystack.
+///
+/// That is, this reports matches of one of two possible bytes. For example,
+/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`,
+/// `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct Three<V> {
+    s1: u8,
+    s2: u8,
+    s3: u8,
+    v1: V,
+    v2: V,
+    v3: V,
+}
+
+impl<V: Vector> Three<V> {
+    /// The number of bytes we examine per each iteration of our search loop.
+    const LOOP_SIZE: usize = 2 * V::BYTES;
+
+    /// Create a new searcher that finds occurrences of the byte given.
+    #[inline(always)]
+    pub(crate) unsafe fn new(
+        needle1: u8,
+        needle2: u8,
+        needle3: u8,
+    ) -> Three<V> {
+        Three {
+            s1: needle1,
+            s2: needle2,
+            s3: needle3,
+            v1: V::splat(needle1),
+            v2: V::splat(needle2),
+            v3: V::splat(needle3),
+        }
+    }
+
+    /// Returns the first needle given to `Three::new`.
+    #[inline(always)]
+    pub(crate) fn needle1(&self) -> u8 {
+        self.s1
+    }
+
+    /// Returns the second needle given to `Three::new`.
+    #[inline(always)]
+    pub(crate) fn needle2(&self) -> u8 {
+        self.s2
+    }
+
+    /// Returns the third needle given to `Three::new`.
+    #[inline(always)]
+    pub(crate) fn needle3(&self) -> u8 {
+        self.s3
+    }
+
+    /// Return a pointer to the first occurrence of one of the needles in the
+    /// given haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// # Safety
+    ///
+    /// * It must be the case that `start < end` and that the distance between
+    /// them is at least equal to `V::BYTES`. That is, it must always be valid
+    /// to do at least an unaligned load of `V` at `start`.
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    #[inline(always)]
+    pub(crate) unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        // If we want to support vectors bigger than 256 bits, we probably
+        // need to move up to using a u64 for the masks used below. Currently
+        // they are 32 bits, which means we're SOL for vectors that need masks
+        // bigger than 32 bits. Overall unclear until there's a use case.
+        debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes");
+
+        let topos = V::Mask::first_offset;
+        let len = end.distance(start);
+        debug_assert!(
+            len >= V::BYTES,
+            "haystack has length {}, but must be at least {}",
+            len,
+            V::BYTES
+        );
+
+        // Search a possibly unaligned chunk at `start`. This covers any part
+        // of the haystack prior to where aligned loads can start.
+        if let Some(cur) = self.search_chunk(start, topos) {
+            return Some(cur);
+        }
+        // Set `cur` to the first V-aligned pointer greater than `start`.
+        let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN));
+        debug_assert!(cur > start && end.sub(V::BYTES) >= start);
+        if len >= Self::LOOP_SIZE {
+            while cur <= end.sub(Self::LOOP_SIZE) {
+                debug_assert_eq!(0, cur.as_usize() % V::BYTES);
+
+                let a = V::load_aligned(cur);
+                let b = V::load_aligned(cur.add(V::BYTES));
+                let eqa1 = self.v1.cmpeq(a);
+                let eqb1 = self.v1.cmpeq(b);
+                let eqa2 = self.v2.cmpeq(a);
+                let eqb2 = self.v2.cmpeq(b);
+                let eqa3 = self.v3.cmpeq(a);
+                let eqb3 = self.v3.cmpeq(b);
+                let or1 = eqa1.or(eqb1);
+                let or2 = eqa2.or(eqb2);
+                let or3 = eqa3.or(eqb3);
+                let or4 = or1.or(or2);
+                let or5 = or3.or(or4);
+                if or5.movemask_will_have_non_zero() {
+                    let mask = eqa1
+                        .movemask()
+                        .or(eqa2.movemask())
+                        .or(eqa3.movemask());
+                    if mask.has_non_zero() {
+                        return Some(cur.add(topos(mask)));
+                    }
+
+                    let mask = eqb1
+                        .movemask()
+                        .or(eqb2.movemask())
+                        .or(eqb3.movemask());
+                    debug_assert!(mask.has_non_zero());
+                    return Some(cur.add(V::BYTES).add(topos(mask)));
+                }
+                cur = cur.add(Self::LOOP_SIZE);
+            }
+        }
+        // Handle any leftovers after the aligned loop above. We use unaligned
+        // loads here, but I believe we are guaranteed that they are aligned
+        // since `cur` is aligned.
+        while cur <= end.sub(V::BYTES) {
+            debug_assert!(end.distance(cur) >= V::BYTES);
+            if let Some(cur) = self.search_chunk(cur, topos) {
+                return Some(cur);
+            }
+            cur = cur.add(V::BYTES);
+        }
+        // Finally handle any remaining bytes less than the size of V. In this
+        // case, our pointer may indeed be unaligned and the load may overlap
+        // with the previous one. But that's okay since we know the previous
+        // load didn't lead to a match (otherwise we wouldn't be here).
+        if cur < end {
+            debug_assert!(end.distance(cur) < V::BYTES);
+            cur = cur.sub(V::BYTES - end.distance(cur));
+            debug_assert_eq!(end.distance(cur), V::BYTES);
+            return self.search_chunk(cur, topos);
+        }
+        None
+    }
+
+    /// Return a pointer to the last occurrence of the needle in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// # Safety
+    ///
+    /// * It must be the case that `start < end` and that the distance between
+    /// them is at least equal to `V::BYTES`. That is, it must always be valid
+    /// to do at least an unaligned load of `V` at `start`.
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    #[inline(always)]
+    pub(crate) unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        // If we want to support vectors bigger than 256 bits, we probably
+        // need to move up to using a u64 for the masks used below. Currently
+        // they are 32 bits, which means we're SOL for vectors that need masks
+        // bigger than 32 bits. Overall unclear until there's a use case.
+        debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes");
+
+        let topos = V::Mask::last_offset;
+        let len = end.distance(start);
+        debug_assert!(
+            len >= V::BYTES,
+            "haystack has length {}, but must be at least {}",
+            len,
+            V::BYTES
+        );
+
+        if let Some(cur) = self.search_chunk(end.sub(V::BYTES), topos) {
+            return Some(cur);
+        }
+        let mut cur = end.sub(end.as_usize() & V::ALIGN);
+        debug_assert!(start <= cur && cur <= end);
+        if len >= Self::LOOP_SIZE {
+            while cur >= start.add(Self::LOOP_SIZE) {
+                debug_assert_eq!(0, cur.as_usize() % V::BYTES);
+
+                cur = cur.sub(Self::LOOP_SIZE);
+                let a = V::load_aligned(cur);
+                let b = V::load_aligned(cur.add(V::BYTES));
+                let eqa1 = self.v1.cmpeq(a);
+                let eqb1 = self.v1.cmpeq(b);
+                let eqa2 = self.v2.cmpeq(a);
+                let eqb2 = self.v2.cmpeq(b);
+                let eqa3 = self.v3.cmpeq(a);
+                let eqb3 = self.v3.cmpeq(b);
+                let or1 = eqa1.or(eqb1);
+                let or2 = eqa2.or(eqb2);
+                let or3 = eqa3.or(eqb3);
+                let or4 = or1.or(or2);
+                let or5 = or3.or(or4);
+                if or5.movemask_will_have_non_zero() {
+                    let mask = eqb1
+                        .movemask()
+                        .or(eqb2.movemask())
+                        .or(eqb3.movemask());
+                    if mask.has_non_zero() {
+                        return Some(cur.add(V::BYTES).add(topos(mask)));
+                    }
+
+                    let mask = eqa1
+                        .movemask()
+                        .or(eqa2.movemask())
+                        .or(eqa3.movemask());
+                    debug_assert!(mask.has_non_zero());
+                    return Some(cur.add(topos(mask)));
+                }
+            }
+        }
+        while cur >= start.add(V::BYTES) {
+            debug_assert!(cur.distance(start) >= V::BYTES);
+            cur = cur.sub(V::BYTES);
+            if let Some(cur) = self.search_chunk(cur, topos) {
+                return Some(cur);
+            }
+        }
+        if cur > start {
+            debug_assert!(cur.distance(start) < V::BYTES);
+            return self.search_chunk(start, topos);
+        }
+        None
+    }
+
+    /// Search `V::BYTES` starting at `cur` via an unaligned load.
+    ///
+    /// `mask_to_offset` should be a function that converts a `movemask` to
+    /// an offset such that `cur.add(offset)` corresponds to a pointer to the
+    /// match location if one is found. Generally it is expected to use either
+    /// `mask_to_first_offset` or `mask_to_last_offset`, depending on whether
+    /// one is implementing a forward or reverse search, respectively.
+    ///
+    /// # Safety
+    ///
+    /// `cur` must be a valid pointer and it must be valid to do an unaligned
+    /// load of size `V::BYTES` at `cur`.
+    #[inline(always)]
+    unsafe fn search_chunk(
+        &self,
+        cur: *const u8,
+        mask_to_offset: impl Fn(V::Mask) -> usize,
+    ) -> Option<*const u8> {
+        let chunk = V::load_unaligned(cur);
+        let eq1 = self.v1.cmpeq(chunk);
+        let eq2 = self.v2.cmpeq(chunk);
+        let eq3 = self.v3.cmpeq(chunk);
+        let mask = eq1.or(eq2).or(eq3).movemask();
+        if mask.has_non_zero() {
+            let mask1 = eq1.movemask();
+            let mask2 = eq2.movemask();
+            let mask3 = eq3.movemask();
+            Some(cur.add(mask_to_offset(mask1.or(mask2).or(mask3))))
+        } else {
+            None
+        }
+    }
+}
+
+/// An iterator over all occurrences of a set of bytes in a haystack.
+///
+/// This iterator implements the routines necessary to provide a
+/// `DoubleEndedIterator` impl, which means it can also be used to find
+/// occurrences in reverse order.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'h` refers to the lifetime of the haystack being searched.
+///
+/// This type is intended to be used to implement all iterators for the
+/// `memchr` family of functions. It handles a tiny bit of marginally tricky
+/// raw pointer math, but otherwise expects the caller to provide `find_raw`
+/// and `rfind_raw` routines for each call of `next` and `next_back`,
+/// respectively.
+#[derive(Clone, Debug)]
+pub(crate) struct Iter<'h> {
+    /// The original starting point into the haystack. We use this to convert
+    /// pointers to offsets.
+    original_start: *const u8,
+    /// The current starting point into the haystack. That is, where the next
+    /// search will begin.
+    start: *const u8,
+    /// The current ending point into the haystack. That is, where the next
+    /// reverse search will begin.
+    end: *const u8,
+    /// A marker for tracking the lifetime of the start/cur_start/cur_end
+    /// pointers above, which all point into the haystack.
+    haystack: core::marker::PhantomData<&'h [u8]>,
+}
+
+// SAFETY: Iter contains no shared references to anything that performs any
+// interior mutations. Also, the lifetime guarantees that Iter will not outlive
+// the haystack.
+unsafe impl<'h> Send for Iter<'h> {}
+
+// SAFETY: Iter perform no interior mutations, therefore no explicit
+// synchronization is necessary. Also, the lifetime guarantees that Iter will
+// not outlive the haystack.
+unsafe impl<'h> Sync for Iter<'h> {}
+
+impl<'h> Iter<'h> {
+    /// Create a new generic memchr iterator.
+    #[inline(always)]
+    pub(crate) fn new(haystack: &'h [u8]) -> Iter<'h> {
+        Iter {
+            original_start: haystack.as_ptr(),
+            start: haystack.as_ptr(),
+            end: haystack.as_ptr().wrapping_add(haystack.len()),
+            haystack: core::marker::PhantomData,
+        }
+    }
+
+    /// Returns the next occurrence in the forward direction.
+    ///
+    /// # Safety
+    ///
+    /// Callers must ensure that if a pointer is returned from the closure
+    /// provided, then it must be greater than or equal to the start pointer
+    /// and less than the end pointer.
+    #[inline(always)]
+    pub(crate) unsafe fn next(
+        &mut self,
+        mut find_raw: impl FnMut(*const u8, *const u8) -> Option<*const u8>,
+    ) -> Option<usize> {
+        // SAFETY: Pointers are derived directly from the same &[u8] haystack.
+        // We only ever modify start/end corresponding to a matching offset
+        // found between start and end. Thus all changes to start/end maintain
+        // our safety requirements.
+        //
+        // The only other assumption we rely on is that the pointer returned
+        // by `find_raw` satisfies `self.start <= found < self.end`, and that
+        // safety contract is forwarded to the caller.
+        let found = find_raw(self.start, self.end)?;
+        let result = found.distance(self.original_start);
+        self.start = found.add(1);
+        Some(result)
+    }
+
+    /// Returns the number of remaining elements in this iterator.
+    #[inline(always)]
+    pub(crate) fn count(
+        self,
+        mut count_raw: impl FnMut(*const u8, *const u8) -> usize,
+    ) -> usize {
+        // SAFETY: Pointers are derived directly from the same &[u8] haystack.
+        // We only ever modify start/end corresponding to a matching offset
+        // found between start and end. Thus all changes to start/end maintain
+        // our safety requirements.
+        count_raw(self.start, self.end)
+    }
+
+    /// Returns the next occurrence in reverse.
+    ///
+    /// # Safety
+    ///
+    /// Callers must ensure that if a pointer is returned from the closure
+    /// provided, then it must be greater than or equal to the start pointer
+    /// and less than the end pointer.
+    #[inline(always)]
+    pub(crate) unsafe fn next_back(
+        &mut self,
+        mut rfind_raw: impl FnMut(*const u8, *const u8) -> Option<*const u8>,
+    ) -> Option<usize> {
+        // SAFETY: Pointers are derived directly from the same &[u8] haystack.
+        // We only ever modify start/end corresponding to a matching offset
+        // found between start and end. Thus all changes to start/end maintain
+        // our safety requirements.
+        //
+        // The only other assumption we rely on is that the pointer returned
+        // by `rfind_raw` satisfies `self.start <= found < self.end`, and that
+        // safety contract is forwarded to the caller.
+        let found = rfind_raw(self.start, self.end)?;
+        let result = found.distance(self.original_start);
+        self.end = found;
+        Some(result)
+    }
+
+    /// Provides an implementation of `Iterator::size_hint`.
+    #[inline(always)]
+    pub(crate) fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, Some(self.end.as_usize().saturating_sub(self.start.as_usize())))
+    }
+}
+
+/// Search a slice using a function that operates on raw pointers.
+///
+/// Given a function to search a contiguous sequence of memory for the location
+/// of a non-empty set of bytes, this will execute that search on a slice of
+/// bytes. The pointer returned by the given function will be converted to an
+/// offset relative to the starting point of the given slice. That is, if a
+/// match is found, the offset returned by this routine is guaranteed to be a
+/// valid index into `haystack`.
+///
+/// Callers may use this for a forward or reverse search.
+///
+/// # Safety
+///
+/// Callers must ensure that if a pointer is returned by `find_raw`, then the
+/// pointer must be greater than or equal to the starting pointer and less than
+/// the end pointer.
+#[inline(always)]
+pub(crate) unsafe fn search_slice_with_raw(
+    haystack: &[u8],
+    mut find_raw: impl FnMut(*const u8, *const u8) -> Option<*const u8>,
+) -> Option<usize> {
+    // SAFETY: We rely on `find_raw` to return a correct and valid pointer, but
+    // otherwise, `start` and `end` are valid due to the guarantees provided by
+    // a &[u8].
+    let start = haystack.as_ptr();
+    let end = start.add(haystack.len());
+    let found = find_raw(start, end)?;
+    Some(found.distance(start))
+}
+
+/// Performs a forward byte-at-a-time loop until either `ptr >= end_ptr` or
+/// until `confirm(*ptr)` returns `true`. If the former occurs, then `None` is
+/// returned. If the latter occurs, then the pointer at which `confirm` returns
+/// `true` is returned.
+///
+/// # Safety
+///
+/// Callers must provide valid pointers and they must satisfy `start_ptr <=
+/// ptr` and `ptr <= end_ptr`.
+#[inline(always)]
+pub(crate) unsafe fn fwd_byte_by_byte<F: Fn(u8) -> bool>(
+    start: *const u8,
+    end: *const u8,
+    confirm: F,
+) -> Option<*const u8> {
+    debug_assert!(start <= end);
+    let mut ptr = start;
+    while ptr < end {
+        if confirm(*ptr) {
+            return Some(ptr);
+        }
+        ptr = ptr.offset(1);
+    }
+    None
+}
+
+/// Performs a reverse byte-at-a-time loop until either `ptr < start_ptr` or
+/// until `confirm(*ptr)` returns `true`. If the former occurs, then `None` is
+/// returned. If the latter occurs, then the pointer at which `confirm` returns
+/// `true` is returned.
+///
+/// # Safety
+///
+/// Callers must provide valid pointers and they must satisfy `start_ptr <=
+/// ptr` and `ptr <= end_ptr`.
+#[inline(always)]
+pub(crate) unsafe fn rev_byte_by_byte<F: Fn(u8) -> bool>(
+    start: *const u8,
+    end: *const u8,
+    confirm: F,
+) -> Option<*const u8> {
+    debug_assert!(start <= end);
+
+    let mut ptr = end;
+    while ptr > start {
+        ptr = ptr.offset(-1);
+        if confirm(*ptr) {
+            return Some(ptr);
+        }
+    }
+    None
+}
+
+/// Performs a forward byte-at-a-time loop until `ptr >= end_ptr` and returns
+/// the number of times `confirm(*ptr)` returns `true`.
+///
+/// # Safety
+///
+/// Callers must provide valid pointers and they must satisfy `start_ptr <=
+/// ptr` and `ptr <= end_ptr`.
+#[inline(always)]
+pub(crate) unsafe fn count_byte_by_byte<F: Fn(u8) -> bool>(
+    start: *const u8,
+    end: *const u8,
+    confirm: F,
+) -> usize {
+    debug_assert!(start <= end);
+    let mut ptr = start;
+    let mut count = 0;
+    while ptr < end {
+        if confirm(*ptr) {
+            count += 1;
+        }
+        ptr = ptr.offset(1);
+    }
+    count
+}
diff --git a/vendor/memchr/src/arch/generic/mod.rs b/vendor/memchr/src/arch/generic/mod.rs
new file mode 100644
index 0000000..63ee3f0
--- /dev/null
+++ b/vendor/memchr/src/arch/generic/mod.rs
@@ -0,0 +1,14 @@
+/*!
+This module defines "generic" routines that can be specialized to specific
+architectures.
+
+We don't expose this module primarily because it would require exposing all
+of the internal infrastructure required to write these generic routines.
+That infrastructure should be treated as an implementation detail so that
+it is allowed to evolve. Instead, what we expose are architecture specific
+instantiations of these generic implementations. The generic code just lets us
+write the code once (usually).
+*/
+
+pub(crate) mod memchr;
+pub(crate) mod packedpair;
diff --git a/vendor/memchr/src/arch/generic/packedpair.rs b/vendor/memchr/src/arch/generic/packedpair.rs
new file mode 100644
index 0000000..8d97cf2
--- /dev/null
+++ b/vendor/memchr/src/arch/generic/packedpair.rs
@@ -0,0 +1,317 @@
+/*!
+Generic crate-internal routines for the "packed pair" SIMD algorithm.
+
+The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main
+difference is that it (by default) uses a background distribution of byte
+frequencies to heuristically select the pair of bytes to search for.
+
+[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last
+*/
+
+use crate::{
+    arch::all::{is_equal_raw, packedpair::Pair},
+    ext::Pointer,
+    vector::{MoveMask, Vector},
+};
+
+/// A generic architecture dependent "packed pair" finder.
+///
+/// This finder picks two bytes that it believes have high predictive power
+/// for indicating an overall match of a needle. Depending on whether
+/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets
+/// where the needle matches or could match. In the prefilter case, candidates
+/// are reported whenever the [`Pair`] of bytes given matches.
+///
+/// This is architecture dependent because it uses specific vector operations
+/// to look for occurrences of the pair of bytes.
+///
+/// This type is not meant to be exported and is instead meant to be used as
+/// the implementation for architecture specific facades. Why? Because it's a
+/// bit of a quirky API that requires `inline(always)` annotations. And pretty
+/// much everything has safety obligations due (at least) to the caller needing
+/// to inline calls into routines marked with
+/// `#[target_feature(enable = "...")]`.
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct Finder<V> {
+    pair: Pair,
+    v1: V,
+    v2: V,
+    min_haystack_len: usize,
+}
+
+impl<V: Vector> Finder<V> {
+    /// Create a new pair searcher. The searcher returned can either report
+    /// exact matches of `needle` or act as a prefilter and report candidate
+    /// positions of `needle`.
+    ///
+    /// # Safety
+    ///
+    /// Callers must ensure that whatever vector type this routine is called
+    /// with is supported by the current environment.
+    ///
+    /// Callers must also ensure that `needle.len() >= 2`.
+    #[inline(always)]
+    pub(crate) unsafe fn new(needle: &[u8], pair: Pair) -> Finder<V> {
+        let max_index = pair.index1().max(pair.index2());
+        let min_haystack_len =
+            core::cmp::max(needle.len(), usize::from(max_index) + V::BYTES);
+        let v1 = V::splat(needle[usize::from(pair.index1())]);
+        let v2 = V::splat(needle[usize::from(pair.index2())]);
+        Finder { pair, v1, v2, min_haystack_len }
+    }
+
+    /// Searches the given haystack for the given needle. The needle given
+    /// should be the same as the needle that this finder was initialized
+    /// with.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// Since this is meant to be used with vector functions, callers need to
+    /// specialize this inside of a function with a `target_feature` attribute.
+    /// Therefore, callers must ensure that whatever target feature is being
+    /// used supports the vector functions that this function is specialized
+    /// for. (For the specific vector functions used, see the Vector trait
+    /// implementations.)
+    #[inline(always)]
+    pub(crate) unsafe fn find(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        assert!(
+            haystack.len() >= self.min_haystack_len,
+            "haystack too small, should be at least {} but got {}",
+            self.min_haystack_len,
+            haystack.len(),
+        );
+
+        let all = V::Mask::all_zeros_except_least_significant(0);
+        let start = haystack.as_ptr();
+        let end = start.add(haystack.len());
+        let max = end.sub(self.min_haystack_len);
+        let mut cur = start;
+
+        // N.B. I did experiment with unrolling the loop to deal with size(V)
+        // bytes at a time and 2*size(V) bytes at a time. The double unroll
+        // was marginally faster while the quadruple unroll was unambiguously
+        // slower. In the end, I decided the complexity from unrolling wasn't
+        // worth it. I used the memmem/krate/prebuilt/huge-en/ benchmarks to
+        // compare.
+        while cur <= max {
+            if let Some(chunki) = self.find_in_chunk(needle, cur, end, all) {
+                return Some(matched(start, cur, chunki));
+            }
+            cur = cur.add(V::BYTES);
+        }
+        if cur < end {
+            let remaining = end.distance(cur);
+            debug_assert!(
+                remaining < self.min_haystack_len,
+                "remaining bytes should be smaller than the minimum haystack \
+                 length of {}, but there are {} bytes remaining",
+                self.min_haystack_len,
+                remaining,
+            );
+            if remaining < needle.len() {
+                return None;
+            }
+            debug_assert!(
+                max < cur,
+                "after main loop, cur should have exceeded max",
+            );
+            let overlap = cur.distance(max);
+            debug_assert!(
+                overlap > 0,
+                "overlap ({}) must always be non-zero",
+                overlap,
+            );
+            debug_assert!(
+                overlap < V::BYTES,
+                "overlap ({}) cannot possibly be >= than a vector ({})",
+                overlap,
+                V::BYTES,
+            );
+            // The mask has all of its bits set except for the first N least
+            // significant bits, where N=overlap. This way, any matches that
+            // occur in find_in_chunk within the overlap are automatically
+            // ignored.
+            let mask = V::Mask::all_zeros_except_least_significant(overlap);
+            cur = max;
+            let m = self.find_in_chunk(needle, cur, end, mask);
+            if let Some(chunki) = m {
+                return Some(matched(start, cur, chunki));
+            }
+        }
+        None
+    }
+
+    /// Searches the given haystack for offsets that represent candidate
+    /// matches of the `needle` given to this finder's constructor. The offsets
+    /// returned, if they are a match, correspond to the starting offset of
+    /// `needle` in the given `haystack`.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// Since this is meant to be used with vector functions, callers need to
+    /// specialize this inside of a function with a `target_feature` attribute.
+    /// Therefore, callers must ensure that whatever target feature is being
+    /// used supports the vector functions that this function is specialized
+    /// for. (For the specific vector functions used, see the Vector trait
+    /// implementations.)
+    #[inline(always)]
+    pub(crate) unsafe fn find_prefilter(
+        &self,
+        haystack: &[u8],
+    ) -> Option<usize> {
+        assert!(
+            haystack.len() >= self.min_haystack_len,
+            "haystack too small, should be at least {} but got {}",
+            self.min_haystack_len,
+            haystack.len(),
+        );
+
+        let start = haystack.as_ptr();
+        let end = start.add(haystack.len());
+        let max = end.sub(self.min_haystack_len);
+        let mut cur = start;
+
+        // N.B. I did experiment with unrolling the loop to deal with size(V)
+        // bytes at a time and 2*size(V) bytes at a time. The double unroll
+        // was marginally faster while the quadruple unroll was unambiguously
+        // slower. In the end, I decided the complexity from unrolling wasn't
+        // worth it. I used the memmem/krate/prebuilt/huge-en/ benchmarks to
+        // compare.
+        while cur <= max {
+            if let Some(chunki) = self.find_prefilter_in_chunk(cur) {
+                return Some(matched(start, cur, chunki));
+            }
+            cur = cur.add(V::BYTES);
+        }
+        if cur < end {
+            // This routine immediately quits if a candidate match is found.
+            // That means that if we're here, no candidate matches have been
+            // found at or before 'ptr'. Thus, we don't need to mask anything
+            // out even though we might technically search part of the haystack
+            // that we've already searched (because we know it can't match).
+            cur = max;
+            if let Some(chunki) = self.find_prefilter_in_chunk(cur) {
+                return Some(matched(start, cur, chunki));
+            }
+        }
+        None
+    }
+
+    /// Search for an occurrence of our byte pair from the needle in the chunk
+    /// pointed to by cur, with the end of the haystack pointed to by end.
+    /// When an occurrence is found, memcmp is run to check if a match occurs
+    /// at the corresponding position.
+    ///
+    /// `mask` should have bits set corresponding the positions in the chunk
+    /// in which matches are considered. This is only used for the last vector
+    /// load where the beginning of the vector might have overlapped with the
+    /// last load in the main loop. The mask lets us avoid visiting positions
+    /// that have already been discarded as matches.
+    ///
+    /// # Safety
+    ///
+    /// It must be safe to do an unaligned read of size(V) bytes starting at
+    /// both (cur + self.index1) and (cur + self.index2). It must also be safe
+    /// to do unaligned loads on cur up to (end - needle.len()).
+    #[inline(always)]
+    unsafe fn find_in_chunk(
+        &self,
+        needle: &[u8],
+        cur: *const u8,
+        end: *const u8,
+        mask: V::Mask,
+    ) -> Option<usize> {
+        let index1 = usize::from(self.pair.index1());
+        let index2 = usize::from(self.pair.index2());
+        let chunk1 = V::load_unaligned(cur.add(index1));
+        let chunk2 = V::load_unaligned(cur.add(index2));
+        let eq1 = chunk1.cmpeq(self.v1);
+        let eq2 = chunk2.cmpeq(self.v2);
+
+        let mut offsets = eq1.and(eq2).movemask().and(mask);
+        while offsets.has_non_zero() {
+            let offset = offsets.first_offset();
+            let cur = cur.add(offset);
+            if end.sub(needle.len()) < cur {
+                return None;
+            }
+            if is_equal_raw(needle.as_ptr(), cur, needle.len()) {
+                return Some(offset);
+            }
+            offsets = offsets.clear_least_significant_bit();
+        }
+        None
+    }
+
+    /// Search for an occurrence of our byte pair from the needle in the chunk
+    /// pointed to by cur, with the end of the haystack pointed to by end.
+    /// When an occurrence is found, memcmp is run to check if a match occurs
+    /// at the corresponding position.
+    ///
+    /// # Safety
+    ///
+    /// It must be safe to do an unaligned read of size(V) bytes starting at
+    /// both (cur + self.index1) and (cur + self.index2). It must also be safe
+    /// to do unaligned reads on cur up to (end - needle.len()).
+    #[inline(always)]
+    unsafe fn find_prefilter_in_chunk(&self, cur: *const u8) -> Option<usize> {
+        let index1 = usize::from(self.pair.index1());
+        let index2 = usize::from(self.pair.index2());
+        let chunk1 = V::load_unaligned(cur.add(index1));
+        let chunk2 = V::load_unaligned(cur.add(index2));
+        let eq1 = chunk1.cmpeq(self.v1);
+        let eq2 = chunk2.cmpeq(self.v2);
+
+        let offsets = eq1.and(eq2).movemask();
+        if !offsets.has_non_zero() {
+            return None;
+        }
+        Some(offsets.first_offset())
+    }
+
+    /// Returns the pair of offsets (into the needle) used to check as a
+    /// predicate before confirming whether a needle exists at a particular
+    /// position.
+    #[inline]
+    pub(crate) fn pair(&self) -> &Pair {
+        &self.pair
+    }
+
+    /// Returns the minimum haystack length that this `Finder` can search.
+    ///
+    /// Providing a haystack to this `Finder` shorter than this length is
+    /// guaranteed to result in a panic.
+    #[inline(always)]
+    pub(crate) fn min_haystack_len(&self) -> usize {
+        self.min_haystack_len
+    }
+}
+
+/// Accepts a chunk-relative offset and returns a haystack relative offset.
+///
+/// This used to be marked `#[cold]` and `#[inline(never)]`, but I couldn't
+/// observe a consistent measureable difference between that and just inlining
+/// it. So we go with inlining it.
+///
+/// # Safety
+///
+/// Same at `ptr::offset_from` in addition to `cur >= start`.
+#[inline(always)]
+unsafe fn matched(start: *const u8, cur: *const u8, chunki: usize) -> usize {
+    cur.distance(start) + chunki
+}
+
+// If you're looking for tests, those are run for each instantiation of the
+// above code. So for example, see arch::x86_64::sse2::packedpair.
diff --git a/vendor/memchr/src/arch/mod.rs b/vendor/memchr/src/arch/mod.rs
new file mode 100644
index 0000000..2f63a1a
--- /dev/null
+++ b/vendor/memchr/src/arch/mod.rs
@@ -0,0 +1,16 @@
+/*!
+A module with low-level architecture dependent routines.
+
+These routines are useful as primitives for tasks not covered by the higher
+level crate API.
+*/
+
+pub mod all;
+pub(crate) mod generic;
+
+#[cfg(target_arch = "aarch64")]
+pub mod aarch64;
+#[cfg(target_arch = "wasm32")]
+pub mod wasm32;
+#[cfg(target_arch = "x86_64")]
+pub mod x86_64;
diff --git a/vendor/memchr/src/arch/wasm32/memchr.rs b/vendor/memchr/src/arch/wasm32/memchr.rs
new file mode 100644
index 0000000..b0bbd1c
--- /dev/null
+++ b/vendor/memchr/src/arch/wasm32/memchr.rs
@@ -0,0 +1,137 @@
+/*!
+Wrapper routines for `memchr` and friends.
+
+These routines choose the best implementation at compile time. (This is
+different from `x86_64` because it is expected that `simd128` is almost always
+available for `wasm32` targets.)
+*/
+
+macro_rules! defraw {
+    ($ty:ident, $find:ident, $start:ident, $end:ident, $($needles:ident),+) => {{
+        #[cfg(target_feature = "simd128")]
+        {
+            use crate::arch::wasm32::simd128::memchr::$ty;
+
+            debug!("chose simd128 for {}", stringify!($ty));
+            debug_assert!($ty::is_available());
+            // SAFETY: We know that wasm memchr is always available whenever
+            // code is compiled for `wasm32` with the `simd128` target feature
+            // enabled.
+            $ty::new_unchecked($($needles),+).$find($start, $end)
+        }
+        #[cfg(not(target_feature = "simd128"))]
+        {
+            use crate::arch::all::memchr::$ty;
+
+            debug!(
+                "no simd128 feature available, using fallback for {}",
+                stringify!($ty),
+            );
+            $ty::new($($needles),+).$find($start, $end)
+        }
+    }}
+}
+
+/// memchr, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::find_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memchr_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(One, find_raw, start, end, n1)
+}
+
+/// memrchr, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::rfind_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memrchr_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(One, rfind_raw, start, end, n1)
+}
+
+/// memchr2, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Two::find_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memchr2_raw(
+    n1: u8,
+    n2: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Two, find_raw, start, end, n1, n2)
+}
+
+/// memrchr2, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Two::rfind_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memrchr2_raw(
+    n1: u8,
+    n2: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Two, rfind_raw, start, end, n1, n2)
+}
+
+/// memchr3, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Three::find_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memchr3_raw(
+    n1: u8,
+    n2: u8,
+    n3: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Three, find_raw, start, end, n1, n2, n3)
+}
+
+/// memrchr3, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Three::rfind_raw`.
+#[inline(always)]
+pub(crate) unsafe fn memrchr3_raw(
+    n1: u8,
+    n2: u8,
+    n3: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    defraw!(Three, rfind_raw, start, end, n1, n2, n3)
+}
+
+/// Count all matching bytes, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::count_raw`.
+#[inline(always)]
+pub(crate) unsafe fn count_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> usize {
+    defraw!(One, count_raw, start, end, n1)
+}
diff --git a/vendor/memchr/src/arch/wasm32/mod.rs b/vendor/memchr/src/arch/wasm32/mod.rs
new file mode 100644
index 0000000..209f876
--- /dev/null
+++ b/vendor/memchr/src/arch/wasm32/mod.rs
@@ -0,0 +1,7 @@
+/*!
+Vector algorithms for the `wasm32` target.
+*/
+
+pub mod simd128;
+
+pub(crate) mod memchr;
diff --git a/vendor/memchr/src/arch/wasm32/simd128/memchr.rs b/vendor/memchr/src/arch/wasm32/simd128/memchr.rs
new file mode 100644
index 0000000..fa314c9
--- /dev/null
+++ b/vendor/memchr/src/arch/wasm32/simd128/memchr.rs
@@ -0,0 +1,1020 @@
+/*!
+This module defines 128-bit vector implementations of `memchr` and friends.
+
+The main types in this module are [`One`], [`Two`] and [`Three`]. They are for
+searching for one, two or three distinct bytes, respectively, in a haystack.
+Each type also has corresponding double ended iterators. These searchers are
+typically much faster than scalar routines accomplishing the same task.
+
+The `One` searcher also provides a [`One::count`] routine for efficiently
+counting the number of times a single byte occurs in a haystack. This is
+useful, for example, for counting the number of lines in a haystack. This
+routine exists because it is usually faster, especially with a high match
+count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its
+`Iterator::count` implementation to use this routine.)
+
+Only one, two and three bytes are supported because three bytes is about
+the point where one sees diminishing returns. Beyond this point and it's
+probably (but not necessarily) better to just use a simple `[bool; 256]` array
+or similar. However, it depends mightily on the specific work-load and the
+expected match frequency.
+*/
+
+use core::arch::wasm32::v128;
+
+use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector};
+
+/// Finds all occurrences of a single byte in a haystack.
+#[derive(Clone, Copy, Debug)]
+pub struct One(generic::One<v128>);
+
+impl One {
+    /// Create a new searcher that finds occurrences of the needle byte given.
+    ///
+    /// This particular searcher is specialized to use simd128 vector
+    /// instructions that typically make it quite fast.
+    ///
+    /// If simd128 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle: u8) -> Option<One> {
+        if One::is_available() {
+            // SAFETY: we check that simd128 is available above.
+            unsafe { Some(One::new_unchecked(needle)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to simd128 vectors and routines without
+    /// checking that simd128 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `simd128`
+    /// instructions in the current environment.
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle: u8) -> One {
+        One(generic::One::new(needle))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`One::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `One::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "simd128")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "simd128"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Counts all occurrences of this byte in the given haystack.
+    #[inline]
+    pub fn count(&self, haystack: &[u8]) -> usize {
+        // SAFETY: All of our pointers are derived directly from a borrowed
+        // slice, which is guaranteed to be valid.
+        unsafe {
+            let start = haystack.as_ptr();
+            let end = start.add(haystack.len());
+            self.count_raw(start, end)
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < v128::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'simd128' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < v128::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'simd128' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Counts all occurrences of this byte in the given haystack represented
+    /// by raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize {
+        if start >= end {
+            return 0;
+        }
+        if end.distance(start) < v128::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::count_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'simd128' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.count_raw_impl(start, end)
+    }
+
+    /// Execute a search using simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a simd128 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a simd128 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Execute a count using simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::count_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a simd128 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn count_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> usize {
+        self.0.count_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> {
+        OneIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of a single byte in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`One::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`One`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct OneIter<'a, 'h> {
+    searcher: &'a One,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for OneIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn count(self) -> usize {
+        self.it.count(|s, e| {
+            // SAFETY: We rely on our generic iterator to return valid start
+            // and end pointers.
+            unsafe { self.searcher.count_raw(s, e) }
+        })
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {}
+
+/// Finds all occurrences of two bytes in a haystack.
+///
+/// That is, this reports matches of one of two possible bytes. For example,
+/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`,
+/// `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Two(generic::Two<v128>);
+
+impl Two {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use simd128 vector
+    /// instructions that typically make it quite fast.
+    ///
+    /// If simd128 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8) -> Option<Two> {
+        if Two::is_available() {
+            // SAFETY: we check that simd128 is available above.
+            unsafe { Some(Two::new_unchecked(needle1, needle2)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to simd128 vectors and routines without
+    /// checking that simd128 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `simd128`
+    /// instructions in the current environment.
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two {
+        Two(generic::Two::new(needle1, needle2))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Two::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Two::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "simd128")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "simd128"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < v128::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1() || b == self.0.needle2()
+            });
+        }
+        // SAFETY: Building a `Two` means it's safe to call 'simd128' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < v128::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1() || b == self.0.needle2()
+            });
+        }
+        // SAFETY: Building a `Two` means it's safe to call 'simd128' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Execute a search using simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a simd128 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a simd128 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle bytes in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> {
+        TwoIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of two possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Two::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Two`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct TwoIter<'a, 'h> {
+    searcher: &'a Two,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for TwoIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {}
+
+/// Finds all occurrences of three bytes in a haystack.
+///
+/// That is, this reports matches of one of three possible bytes. For example,
+/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets
+/// `0`, `2`, `3`, `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Three(generic::Three<v128>);
+
+impl Three {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use simd128 vector
+    /// instructions that typically make it quite fast.
+    ///
+    /// If simd128 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> {
+        if Three::is_available() {
+            // SAFETY: we check that simd128 is available above.
+            unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to simd128 vectors and routines without
+    /// checking that simd128 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `simd128`
+    /// instructions in the current environment.
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    pub unsafe fn new_unchecked(
+        needle1: u8,
+        needle2: u8,
+        needle3: u8,
+    ) -> Three {
+        Three(generic::Three::new(needle1, needle2, needle3))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Three::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Three::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "simd128")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "simd128"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < v128::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+                    || b == self.0.needle2()
+                    || b == self.0.needle3()
+            });
+        }
+        // SAFETY: Building a `Three` means it's safe to call 'simd128'
+        // routines. Also, we've checked that our haystack is big enough to run
+        // on the vector routine. Pointer validity is caller's responsibility.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < v128::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+                    || b == self.0.needle2()
+                    || b == self.0.needle3()
+            });
+        }
+        // SAFETY: Building a `Three` means it's safe to call 'simd128'
+        // routines. Also, we've checked that our haystack is big enough to run
+        // on the vector routine. Pointer validity is caller's responsibility.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Execute a search using simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a simd128 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of a simd128 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> {
+        ThreeIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of three possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Three::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Three`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct ThreeIter<'a, 'h> {
+    searcher: &'a Three,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for ThreeIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    define_memchr_quickcheck!(super);
+
+    #[test]
+    fn forward_one() {
+        crate::tests::memchr::Runner::new(1).forward_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_one() {
+        crate::tests::memchr::Runner::new(1).reverse_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn count_one() {
+        crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| {
+            Some(One::new(needles[0])?.iter(haystack).count())
+        })
+    }
+
+    #[test]
+    fn forward_two() {
+        crate::tests::memchr::Runner::new(2).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_two() {
+        crate::tests::memchr::Runner::new(2).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn forward_three() {
+        crate::tests::memchr::Runner::new(3).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_three() {
+        crate::tests::memchr::Runner::new(3).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+}
diff --git a/vendor/memchr/src/arch/wasm32/simd128/mod.rs b/vendor/memchr/src/arch/wasm32/simd128/mod.rs
new file mode 100644
index 0000000..b55d1f0
--- /dev/null
+++ b/vendor/memchr/src/arch/wasm32/simd128/mod.rs
@@ -0,0 +1,6 @@
+/*!
+Algorithms for the `wasm32` target using 128-bit vectors via simd128.
+*/
+
+pub mod memchr;
+pub mod packedpair;
diff --git a/vendor/memchr/src/arch/wasm32/simd128/packedpair.rs b/vendor/memchr/src/arch/wasm32/simd128/packedpair.rs
new file mode 100644
index 0000000..b629377
--- /dev/null
+++ b/vendor/memchr/src/arch/wasm32/simd128/packedpair.rs
@@ -0,0 +1,229 @@
+/*!
+A 128-bit vector implementation of the "packed pair" SIMD algorithm.
+
+The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main
+difference is that it (by default) uses a background distribution of byte
+frequencies to heuristically select the pair of bytes to search for.
+
+[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last
+*/
+
+use core::arch::wasm32::v128;
+
+use crate::arch::{all::packedpair::Pair, generic::packedpair};
+
+/// A "packed pair" finder that uses 128-bit vector operations.
+///
+/// This finder picks two bytes that it believes have high predictive power
+/// for indicating an overall match of a needle. Depending on whether
+/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets
+/// where the needle matches or could match. In the prefilter case, candidates
+/// are reported whenever the [`Pair`] of bytes given matches.
+#[derive(Clone, Copy, Debug)]
+pub struct Finder(packedpair::Finder<v128>);
+
+impl Finder {
+    /// Create a new pair searcher. The searcher returned can either report
+    /// exact matches of `needle` or act as a prefilter and report candidate
+    /// positions of `needle`.
+    ///
+    /// If simd128 is unavailable in the current environment or if a [`Pair`]
+    /// could not be constructed from the needle given, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Option<Finder> {
+        Finder::with_pair(needle, Pair::new(needle)?)
+    }
+
+    /// Create a new "packed pair" finder using the pair of bytes given.
+    ///
+    /// This constructor permits callers to control precisely which pair of
+    /// bytes is used as a predicate.
+    ///
+    /// If simd128 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> {
+        if Finder::is_available() {
+            // SAFETY: we check that simd128 is available above. We are also
+            // guaranteed to have needle.len() > 1 because we have a valid
+            // Pair.
+            unsafe { Some(Finder::with_pair_impl(needle, pair)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new `Finder` specific to simd128 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as the safety for `packedpair::Finder::new`, and callers must also
+    /// ensure that simd128 is available.
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder {
+        let finder = packedpair::Finder::<v128>::new(needle, pair);
+        Finder(finder)
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Finder::with_pair`] will
+    /// return a `Some` value. Similarly, when it is false, it is guaranteed
+    /// that `Finder::with_pair` will return a `None` value. Notice that this
+    /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely,
+    /// even when `Finder::is_available` is true, it is not guaranteed that a
+    /// valid [`Pair`] can be found from the needle given.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "simd128")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "simd128"))]
+        {
+            false
+        }
+    }
+
+    /// Execute a search using wasm32 v128 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        self.find_impl(haystack, needle)
+    }
+
+    /// Execute a search using wasm32 v128 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> {
+        self.find_prefilter_impl(haystack)
+    }
+
+    /// Execute a search using wasm32 v128 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    fn find_impl(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        // SAFETY: The target feature safety obligation is automatically
+        // fulfilled by virtue of being a method on `Finder`, which can only be
+        // constructed when it is safe to call `simd128` routines.
+        unsafe { self.0.find(haystack, needle) }
+    }
+
+    /// Execute a prefilter search using wasm32 v128 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `simd128` routines.)
+    #[target_feature(enable = "simd128")]
+    #[inline]
+    fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: The target feature safety obligation is automatically
+        // fulfilled by virtue of being a method on `Finder`, which can only be
+        // constructed when it is safe to call `simd128` routines.
+        unsafe { self.0.find_prefilter(haystack) }
+    }
+
+    /// Returns the pair of offsets (into the needle) used to check as a
+    /// predicate before confirming whether a needle exists at a particular
+    /// position.
+    #[inline]
+    pub fn pair(&self) -> &Pair {
+        self.0.pair()
+    }
+
+    /// Returns the minimum haystack length that this `Finder` can search.
+    ///
+    /// Using a haystack with length smaller than this in a search will result
+    /// in a panic. The reason for this restriction is that this finder is
+    /// meant to be a low-level component that is part of a larger substring
+    /// strategy. In that sense, it avoids trying to handle all cases and
+    /// instead only handles the cases that it can handle very well.
+    #[inline]
+    pub fn min_haystack_len(&self) -> usize {
+        self.0.min_haystack_len()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> {
+        let f = Finder::new(needle)?;
+        if haystack.len() < f.min_haystack_len() {
+            return None;
+        }
+        Some(f.find(haystack, needle))
+    }
+
+    define_substring_forward_quickcheck!(find);
+
+    #[test]
+    fn forward_substring() {
+        crate::tests::substring::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find(haystack, needle))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair_prefilter() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find_prefilter(haystack))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+}
diff --git a/vendor/memchr/src/arch/x86_64/avx2/memchr.rs b/vendor/memchr/src/arch/x86_64/avx2/memchr.rs
new file mode 100644
index 0000000..59f8c7f
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/avx2/memchr.rs
@@ -0,0 +1,1352 @@
+/*!
+This module defines 256-bit vector implementations of `memchr` and friends.
+
+The main types in this module are [`One`], [`Two`] and [`Three`]. They are for
+searching for one, two or three distinct bytes, respectively, in a haystack.
+Each type also has corresponding double ended iterators. These searchers are
+typically much faster than scalar routines accomplishing the same task.
+
+The `One` searcher also provides a [`One::count`] routine for efficiently
+counting the number of times a single byte occurs in a haystack. This is
+useful, for example, for counting the number of lines in a haystack. This
+routine exists because it is usually faster, especially with a high match
+count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its
+`Iterator::count` implementation to use this routine.)
+
+Only one, two and three bytes are supported because three bytes is about
+the point where one sees diminishing returns. Beyond this point and it's
+probably (but not necessarily) better to just use a simple `[bool; 256]` array
+or similar. However, it depends mightily on the specific work-load and the
+expected match frequency.
+*/
+
+use core::arch::x86_64::{__m128i, __m256i};
+
+use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector};
+
+/// Finds all occurrences of a single byte in a haystack.
+#[derive(Clone, Copy, Debug)]
+pub struct One {
+    /// Used for haystacks less than 32 bytes.
+    sse2: generic::One<__m128i>,
+    /// Used for haystacks bigger than 32 bytes.
+    avx2: generic::One<__m256i>,
+}
+
+impl One {
+    /// Create a new searcher that finds occurrences of the needle byte given.
+    ///
+    /// This particular searcher is specialized to use AVX2 vector instructions
+    /// that typically make it quite fast. (SSE2 is used for haystacks that
+    /// are too short to accommodate an AVX2 vector.)
+    ///
+    /// If either SSE2 or AVX2 is unavailable in the current environment, then
+    /// `None` is returned.
+    #[inline]
+    pub fn new(needle: u8) -> Option<One> {
+        if One::is_available() {
+            // SAFETY: we check that sse2 and avx2 are available above.
+            unsafe { Some(One::new_unchecked(needle)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to AVX2 vectors and routines without
+    /// checking that either SSE2 or AVX2 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute both `sse2` and
+    /// `avx2` instructions in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to SSE2
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "sse2", enable = "avx2")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle: u8) -> One {
+        One {
+            sse2: generic::One::new(needle),
+            avx2: generic::One::new(needle),
+        }
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`One::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `One::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+        #[cfg(target_feature = "sse2")]
+        {
+            #[cfg(target_feature = "avx2")]
+            {
+                true
+            }
+            #[cfg(not(target_feature = "avx2"))]
+            {
+                #[cfg(feature = "std")]
+                {
+                    std::is_x86_feature_detected!("avx2")
+                }
+                #[cfg(not(feature = "std"))]
+                {
+                    false
+                }
+            }
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Counts all occurrences of this byte in the given haystack.
+    #[inline]
+    pub fn count(&self, haystack: &[u8]) -> usize {
+        // SAFETY: All of our pointers are derived directly from a borrowed
+        // slice, which is guaranteed to be valid.
+        unsafe {
+            let start = haystack.as_ptr();
+            let end = start.add(haystack.len());
+            self.count_raw(start, end)
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let len = end.distance(start);
+        if len < __m256i::BYTES {
+            return if len < __m128i::BYTES {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                generic::fwd_byte_by_byte(start, end, |b| {
+                    b == self.sse2.needle1()
+                })
+            } else {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                self.find_raw_sse2(start, end)
+            };
+        }
+        // SAFETY: Building a `One` means it's safe to call both 'sse2' and
+        // 'avx2' routines. Also, we've checked that our haystack is big
+        // enough to run on the vector routine. Pointer validity is caller's
+        // responsibility.
+        //
+        // Note that we could call `self.avx2.find_raw` directly here. But that
+        // means we'd have to annotate this routine with `target_feature`.
+        // Which is fine, because this routine is `unsafe` anyway and the
+        // `target_feature` obligation is met by virtue of building a `One`.
+        // The real problem is that a routine with a `target_feature`
+        // annotation generally can't be inlined into caller code unless
+        // the caller code has the same target feature annotations. Namely,
+        // the common case (at time of writing) is for calling code to not
+        // have the `avx2` target feature enabled *at compile time*. Without
+        // `target_feature` on this routine, it can be inlined which will
+        // handle some of the short-haystack cases above without touching the
+        // architecture specific code.
+        self.find_raw_avx2(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let len = end.distance(start);
+        if len < __m256i::BYTES {
+            return if len < __m128i::BYTES {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                generic::rev_byte_by_byte(start, end, |b| {
+                    b == self.sse2.needle1()
+                })
+            } else {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                self.rfind_raw_sse2(start, end)
+            };
+        }
+        // SAFETY: Building a `One` means it's safe to call both 'sse2' and
+        // 'avx2' routines. Also, we've checked that our haystack is big
+        // enough to run on the vector routine. Pointer validity is caller's
+        // responsibility.
+        //
+        // See note in forward routine above for why we don't just call
+        // `self.avx2.rfind_raw` directly here.
+        self.rfind_raw_avx2(start, end)
+    }
+
+    /// Counts all occurrences of this byte in the given haystack represented
+    /// by raw pointers.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `0` will always be returned.
+    #[inline]
+    pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize {
+        if start >= end {
+            return 0;
+        }
+        let len = end.distance(start);
+        if len < __m256i::BYTES {
+            return if len < __m128i::BYTES {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                generic::count_byte_by_byte(start, end, |b| {
+                    b == self.sse2.needle1()
+                })
+            } else {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                self.count_raw_sse2(start, end)
+            };
+        }
+        // SAFETY: Building a `One` means it's safe to call both 'sse2' and
+        // 'avx2' routines. Also, we've checked that our haystack is big
+        // enough to run on the vector routine. Pointer validity is caller's
+        // responsibility.
+        self.count_raw_avx2(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_raw_sse2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.sse2.find_raw(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn rfind_raw_sse2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.sse2.rfind_raw(start, end)
+    }
+
+    /// Execute a count using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::count_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn count_raw_sse2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> usize {
+        self.sse2.count_raw(start, end)
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an AVX2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    unsafe fn find_raw_avx2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.avx2.find_raw(start, end)
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an AVX2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    unsafe fn rfind_raw_avx2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.avx2.rfind_raw(start, end)
+    }
+
+    /// Execute a count using AVX2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::count_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an AVX2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    unsafe fn count_raw_avx2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> usize {
+        self.avx2.count_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> {
+        OneIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of a single byte in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`One::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`One`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct OneIter<'a, 'h> {
+    searcher: &'a One,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for OneIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn count(self) -> usize {
+        self.it.count(|s, e| {
+            // SAFETY: We rely on our generic iterator to return valid start
+            // and end pointers.
+            unsafe { self.searcher.count_raw(s, e) }
+        })
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {}
+
+/// Finds all occurrences of two bytes in a haystack.
+///
+/// That is, this reports matches of one of two possible bytes. For example,
+/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`,
+/// `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Two {
+    /// Used for haystacks less than 32 bytes.
+    sse2: generic::Two<__m128i>,
+    /// Used for haystacks bigger than 32 bytes.
+    avx2: generic::Two<__m256i>,
+}
+
+impl Two {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use AVX2 vector instructions
+    /// that typically make it quite fast. (SSE2 is used for haystacks that
+    /// are too short to accommodate an AVX2 vector.)
+    ///
+    /// If either SSE2 or AVX2 is unavailable in the current environment, then
+    /// `None` is returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8) -> Option<Two> {
+        if Two::is_available() {
+            // SAFETY: we check that sse2 and avx2 are available above.
+            unsafe { Some(Two::new_unchecked(needle1, needle2)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to AVX2 vectors and routines without
+    /// checking that either SSE2 or AVX2 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute both `sse2` and
+    /// `avx2` instructions in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to SSE2
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "sse2", enable = "avx2")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two {
+        Two {
+            sse2: generic::Two::new(needle1, needle2),
+            avx2: generic::Two::new(needle1, needle2),
+        }
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Two::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Two::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+        #[cfg(target_feature = "sse2")]
+        {
+            #[cfg(target_feature = "avx2")]
+            {
+                true
+            }
+            #[cfg(not(target_feature = "avx2"))]
+            {
+                #[cfg(feature = "std")]
+                {
+                    std::is_x86_feature_detected!("avx2")
+                }
+                #[cfg(not(feature = "std"))]
+                {
+                    false
+                }
+            }
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let len = end.distance(start);
+        if len < __m256i::BYTES {
+            return if len < __m128i::BYTES {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                generic::fwd_byte_by_byte(start, end, |b| {
+                    b == self.sse2.needle1() || b == self.sse2.needle2()
+                })
+            } else {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                self.find_raw_sse2(start, end)
+            };
+        }
+        // SAFETY: Building a `Two` means it's safe to call both 'sse2' and
+        // 'avx2' routines. Also, we've checked that our haystack is big
+        // enough to run on the vector routine. Pointer validity is caller's
+        // responsibility.
+        //
+        // Note that we could call `self.avx2.find_raw` directly here. But that
+        // means we'd have to annotate this routine with `target_feature`.
+        // Which is fine, because this routine is `unsafe` anyway and the
+        // `target_feature` obligation is met by virtue of building a `Two`.
+        // The real problem is that a routine with a `target_feature`
+        // annotation generally can't be inlined into caller code unless
+        // the caller code has the same target feature annotations. Namely,
+        // the common case (at time of writing) is for calling code to not
+        // have the `avx2` target feature enabled *at compile time*. Without
+        // `target_feature` on this routine, it can be inlined which will
+        // handle some of the short-haystack cases above without touching the
+        // architecture specific code.
+        self.find_raw_avx2(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let len = end.distance(start);
+        if len < __m256i::BYTES {
+            return if len < __m128i::BYTES {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                generic::rev_byte_by_byte(start, end, |b| {
+                    b == self.sse2.needle1() || b == self.sse2.needle2()
+                })
+            } else {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                self.rfind_raw_sse2(start, end)
+            };
+        }
+        // SAFETY: Building a `Two` means it's safe to call both 'sse2' and
+        // 'avx2' routines. Also, we've checked that our haystack is big
+        // enough to run on the vector routine. Pointer validity is caller's
+        // responsibility.
+        //
+        // See note in forward routine above for why we don't just call
+        // `self.avx2.rfind_raw` directly here.
+        self.rfind_raw_avx2(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_raw_sse2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.sse2.find_raw(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn rfind_raw_sse2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.sse2.rfind_raw(start, end)
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an AVX2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    unsafe fn find_raw_avx2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.avx2.find_raw(start, end)
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an AVX2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    unsafe fn rfind_raw_avx2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.avx2.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle bytes in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> {
+        TwoIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of two possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Two::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Two`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct TwoIter<'a, 'h> {
+    searcher: &'a Two,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for TwoIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {}
+
+/// Finds all occurrences of three bytes in a haystack.
+///
+/// That is, this reports matches of one of three possible bytes. For example,
+/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets
+/// `0`, `2`, `3`, `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Three {
+    /// Used for haystacks less than 32 bytes.
+    sse2: generic::Three<__m128i>,
+    /// Used for haystacks bigger than 32 bytes.
+    avx2: generic::Three<__m256i>,
+}
+
+impl Three {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use AVX2 vector instructions
+    /// that typically make it quite fast. (SSE2 is used for haystacks that
+    /// are too short to accommodate an AVX2 vector.)
+    ///
+    /// If either SSE2 or AVX2 is unavailable in the current environment, then
+    /// `None` is returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> {
+        if Three::is_available() {
+            // SAFETY: we check that sse2 and avx2 are available above.
+            unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to AVX2 vectors and routines without
+    /// checking that either SSE2 or AVX2 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute both `sse2` and
+    /// `avx2` instructions in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to SSE2
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "sse2", enable = "avx2")]
+    #[inline]
+    pub unsafe fn new_unchecked(
+        needle1: u8,
+        needle2: u8,
+        needle3: u8,
+    ) -> Three {
+        Three {
+            sse2: generic::Three::new(needle1, needle2, needle3),
+            avx2: generic::Three::new(needle1, needle2, needle3),
+        }
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Three::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Three::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+        #[cfg(target_feature = "sse2")]
+        {
+            #[cfg(target_feature = "avx2")]
+            {
+                true
+            }
+            #[cfg(not(target_feature = "avx2"))]
+            {
+                #[cfg(feature = "std")]
+                {
+                    std::is_x86_feature_detected!("avx2")
+                }
+                #[cfg(not(feature = "std"))]
+                {
+                    false
+                }
+            }
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let len = end.distance(start);
+        if len < __m256i::BYTES {
+            return if len < __m128i::BYTES {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                generic::fwd_byte_by_byte(start, end, |b| {
+                    b == self.sse2.needle1()
+                        || b == self.sse2.needle2()
+                        || b == self.sse2.needle3()
+                })
+            } else {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                self.find_raw_sse2(start, end)
+            };
+        }
+        // SAFETY: Building a `Three` means it's safe to call both 'sse2' and
+        // 'avx2' routines. Also, we've checked that our haystack is big
+        // enough to run on the vector routine. Pointer validity is caller's
+        // responsibility.
+        //
+        // Note that we could call `self.avx2.find_raw` directly here. But that
+        // means we'd have to annotate this routine with `target_feature`.
+        // Which is fine, because this routine is `unsafe` anyway and the
+        // `target_feature` obligation is met by virtue of building a `Three`.
+        // The real problem is that a routine with a `target_feature`
+        // annotation generally can't be inlined into caller code unless
+        // the caller code has the same target feature annotations. Namely,
+        // the common case (at time of writing) is for calling code to not
+        // have the `avx2` target feature enabled *at compile time*. Without
+        // `target_feature` on this routine, it can be inlined which will
+        // handle some of the short-haystack cases above without touching the
+        // architecture specific code.
+        self.find_raw_avx2(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        let len = end.distance(start);
+        if len < __m256i::BYTES {
+            return if len < __m128i::BYTES {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                generic::rev_byte_by_byte(start, end, |b| {
+                    b == self.sse2.needle1()
+                        || b == self.sse2.needle2()
+                        || b == self.sse2.needle3()
+                })
+            } else {
+                // SAFETY: We require the caller to pass valid start/end
+                // pointers.
+                self.rfind_raw_sse2(start, end)
+            };
+        }
+        // SAFETY: Building a `Three` means it's safe to call both 'sse2' and
+        // 'avx2' routines. Also, we've checked that our haystack is big
+        // enough to run on the vector routine. Pointer validity is caller's
+        // responsibility.
+        //
+        // See note in forward routine above for why we don't just call
+        // `self.avx2.rfind_raw` directly here.
+        self.rfind_raw_avx2(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_raw_sse2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.sse2.find_raw(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn rfind_raw_sse2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.sse2.rfind_raw(start, end)
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an AVX2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    unsafe fn find_raw_avx2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.avx2.find_raw(start, end)
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an AVX2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `sse2`/`avx2` routines.)
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    unsafe fn rfind_raw_avx2(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.avx2.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle bytes in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> {
+        ThreeIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of three possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Three::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Three`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct ThreeIter<'a, 'h> {
+    searcher: &'a Three,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for ThreeIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    define_memchr_quickcheck!(super);
+
+    #[test]
+    fn forward_one() {
+        crate::tests::memchr::Runner::new(1).forward_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_one() {
+        crate::tests::memchr::Runner::new(1).reverse_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn count_one() {
+        crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| {
+            Some(One::new(needles[0])?.iter(haystack).count())
+        })
+    }
+
+    #[test]
+    fn forward_two() {
+        crate::tests::memchr::Runner::new(2).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_two() {
+        crate::tests::memchr::Runner::new(2).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn forward_three() {
+        crate::tests::memchr::Runner::new(3).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_three() {
+        crate::tests::memchr::Runner::new(3).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+}
diff --git a/vendor/memchr/src/arch/x86_64/avx2/mod.rs b/vendor/memchr/src/arch/x86_64/avx2/mod.rs
new file mode 100644
index 0000000..ee4097d
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/avx2/mod.rs
@@ -0,0 +1,6 @@
+/*!
+Algorithms for the `x86_64` target using 256-bit vectors via AVX2.
+*/
+
+pub mod memchr;
+pub mod packedpair;
diff --git a/vendor/memchr/src/arch/x86_64/avx2/packedpair.rs b/vendor/memchr/src/arch/x86_64/avx2/packedpair.rs
new file mode 100644
index 0000000..efae7b6
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/avx2/packedpair.rs
@@ -0,0 +1,272 @@
+/*!
+A 256-bit vector implementation of the "packed pair" SIMD algorithm.
+
+The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main
+difference is that it (by default) uses a background distribution of byte
+frequencies to heuristically select the pair of bytes to search for.
+
+[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last
+*/
+
+use core::arch::x86_64::{__m128i, __m256i};
+
+use crate::arch::{all::packedpair::Pair, generic::packedpair};
+
+/// A "packed pair" finder that uses 256-bit vector operations.
+///
+/// This finder picks two bytes that it believes have high predictive power
+/// for indicating an overall match of a needle. Depending on whether
+/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets
+/// where the needle matches or could match. In the prefilter case, candidates
+/// are reported whenever the [`Pair`] of bytes given matches.
+#[derive(Clone, Copy, Debug)]
+pub struct Finder {
+    sse2: packedpair::Finder<__m128i>,
+    avx2: packedpair::Finder<__m256i>,
+}
+
+impl Finder {
+    /// Create a new pair searcher. The searcher returned can either report
+    /// exact matches of `needle` or act as a prefilter and report candidate
+    /// positions of `needle`.
+    ///
+    /// If AVX2 is unavailable in the current environment or if a [`Pair`]
+    /// could not be constructed from the needle given, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Option<Finder> {
+        Finder::with_pair(needle, Pair::new(needle)?)
+    }
+
+    /// Create a new "packed pair" finder using the pair of bytes given.
+    ///
+    /// This constructor permits callers to control precisely which pair of
+    /// bytes is used as a predicate.
+    ///
+    /// If AVX2 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> {
+        if Finder::is_available() {
+            // SAFETY: we check that sse2/avx2 is available above. We are also
+            // guaranteed to have needle.len() > 1 because we have a valid
+            // Pair.
+            unsafe { Some(Finder::with_pair_impl(needle, pair)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new `Finder` specific to SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as the safety for `packedpair::Finder::new`, and callers must also
+    /// ensure that both SSE2 and AVX2 are available.
+    #[target_feature(enable = "sse2", enable = "avx2")]
+    #[inline]
+    unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder {
+        let sse2 = packedpair::Finder::<__m128i>::new(needle, pair);
+        let avx2 = packedpair::Finder::<__m256i>::new(needle, pair);
+        Finder { sse2, avx2 }
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Finder::with_pair`] will
+    /// return a `Some` value. Similarly, when it is false, it is guaranteed
+    /// that `Finder::with_pair` will return a `None` value. Notice that this
+    /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely,
+    /// even when `Finder::is_available` is true, it is not guaranteed that a
+    /// valid [`Pair`] can be found from the needle given.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+        #[cfg(target_feature = "sse2")]
+        {
+            #[cfg(target_feature = "avx2")]
+            {
+                true
+            }
+            #[cfg(not(target_feature = "avx2"))]
+            {
+                #[cfg(feature = "std")]
+                {
+                    std::is_x86_feature_detected!("avx2")
+                }
+                #[cfg(not(feature = "std"))]
+                {
+                    false
+                }
+            }
+        }
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines.
+        unsafe { self.find_impl(haystack, needle) }
+    }
+
+    /// Run this finder on the given haystack as a prefilter.
+    ///
+    /// If a candidate match is found, then an offset where the needle *could*
+    /// begin in the haystack is returned.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines.
+        unsafe { self.find_prefilter_impl(haystack) }
+    }
+
+    /// Execute a search using AVX2 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `sse2` and `avx2` routines.)
+    #[target_feature(enable = "sse2", enable = "avx2")]
+    #[inline]
+    unsafe fn find_impl(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        if haystack.len() < self.avx2.min_haystack_len() {
+            self.sse2.find(haystack, needle)
+        } else {
+            self.avx2.find(haystack, needle)
+        }
+    }
+
+    /// Execute a prefilter search using AVX2 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `sse2` and `avx2` routines.)
+    #[target_feature(enable = "sse2", enable = "avx2")]
+    #[inline]
+    unsafe fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> {
+        if haystack.len() < self.avx2.min_haystack_len() {
+            self.sse2.find_prefilter(haystack)
+        } else {
+            self.avx2.find_prefilter(haystack)
+        }
+    }
+
+    /// Returns the pair of offsets (into the needle) used to check as a
+    /// predicate before confirming whether a needle exists at a particular
+    /// position.
+    #[inline]
+    pub fn pair(&self) -> &Pair {
+        self.avx2.pair()
+    }
+
+    /// Returns the minimum haystack length that this `Finder` can search.
+    ///
+    /// Using a haystack with length smaller than this in a search will result
+    /// in a panic. The reason for this restriction is that this finder is
+    /// meant to be a low-level component that is part of a larger substring
+    /// strategy. In that sense, it avoids trying to handle all cases and
+    /// instead only handles the cases that it can handle very well.
+    #[inline]
+    pub fn min_haystack_len(&self) -> usize {
+        // The caller doesn't need to care about AVX2's min_haystack_len
+        // since this implementation will automatically switch to the SSE2
+        // implementation if the haystack is too short for AVX2. Therefore, the
+        // caller only needs to care about SSE2's min_haystack_len.
+        //
+        // This does assume that SSE2's min_haystack_len is less than or
+        // equal to AVX2's min_haystack_len. In practice, this is true and
+        // there is no way it could be false based on how this Finder is
+        // implemented. Namely, both SSE2 and AVX2 use the same `Pair`. If
+        // they used different pairs, then it's possible (although perhaps
+        // pathological) for SSE2's min_haystack_len to be bigger than AVX2's.
+        self.sse2.min_haystack_len()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> {
+        let f = Finder::new(needle)?;
+        if haystack.len() < f.min_haystack_len() {
+            return None;
+        }
+        Some(f.find(haystack, needle))
+    }
+
+    define_substring_forward_quickcheck!(find);
+
+    #[test]
+    fn forward_substring() {
+        crate::tests::substring::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find(haystack, needle))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair_prefilter() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            if !cfg!(target_feature = "sse2") {
+                return None;
+            }
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find_prefilter(haystack))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+}
diff --git a/vendor/memchr/src/arch/x86_64/memchr.rs b/vendor/memchr/src/arch/x86_64/memchr.rs
new file mode 100644
index 0000000..fcb1399
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/memchr.rs
@@ -0,0 +1,335 @@
+/*!
+Wrapper routines for `memchr` and friends.
+
+These routines efficiently dispatch to the best implementation based on what
+the CPU supports.
+*/
+
+/// Provides a way to run a memchr-like function while amortizing the cost of
+/// runtime CPU feature detection.
+///
+/// This works by loading a function pointer from an atomic global. Initially,
+/// this global is set to a function that does CPU feature detection. For
+/// example, if AVX2 is enabled, then the AVX2 implementation is used.
+/// Otherwise, at least on x86_64, the SSE2 implementation is used. (And
+/// in some niche cases, if SSE2 isn't available, then the architecture
+/// independent fallback implementation is used.)
+///
+/// After the first call to this function, the atomic global is replaced with
+/// the specific AVX2, SSE2 or fallback routine chosen. Subsequent calls then
+/// will directly call the chosen routine instead of needing to go through the
+/// CPU feature detection branching again.
+///
+/// This particular macro is specifically written to provide the implementation
+/// of functions with the following signature:
+///
+/// ```ignore
+/// fn memchr(needle1: u8, start: *const u8, end: *const u8) -> Option<usize>;
+/// ```
+///
+/// Where you can also have `memchr2` and `memchr3`, but with `needle2` and
+/// `needle3`, respectively. The `start` and `end` parameters correspond to the
+/// start and end of the haystack, respectively.
+///
+/// We use raw pointers here instead of the more obvious `haystack: &[u8]` so
+/// that the function is compatible with our lower level iterator logic that
+/// operates on raw pointers. We use this macro to implement "raw" memchr
+/// routines with the signature above, and then define memchr routines using
+/// regular slices on top of them.
+///
+/// Note that we use `#[cfg(target_feature = "sse2")]` below even though
+/// it shouldn't be strictly necessary because without it, it seems to
+/// cause the compiler to blow up. I guess it can't handle a function
+/// pointer being created with a sse target feature? Dunno. See the
+/// `build-for-x86-64-but-non-sse-target` CI job if you want to experiment with
+/// this.
+///
+/// # Safety
+///
+/// Primarily callers must that `$fnty` is a correct function pointer type and
+/// not something else.
+///
+/// Callers must also ensure that `$memchrty::$memchrfind` corresponds to a
+/// routine that returns a valid function pointer when a match is found. That
+/// is, a pointer that is `>= start` and `< end`.
+///
+/// Callers must also ensure that the `$hay_start` and `$hay_end` identifiers
+/// correspond to valid pointers.
+macro_rules! unsafe_ifunc {
+    (
+        $memchrty:ident,
+        $memchrfind:ident,
+        $fnty:ty,
+        $retty:ty,
+        $hay_start:ident,
+        $hay_end:ident,
+        $($needle:ident),+
+    ) => {{
+        #![allow(unused_unsafe)]
+
+        use core::sync::atomic::{AtomicPtr, Ordering};
+
+        type Fn = *mut ();
+        type RealFn = $fnty;
+        static FN: AtomicPtr<()> = AtomicPtr::new(detect as Fn);
+
+        #[cfg(target_feature = "sse2")]
+        #[target_feature(enable = "sse2", enable = "avx2")]
+        unsafe fn find_avx2(
+            $($needle: u8),+,
+            $hay_start: *const u8,
+            $hay_end: *const u8,
+        ) -> $retty {
+            use crate::arch::x86_64::avx2::memchr::$memchrty;
+            $memchrty::new_unchecked($($needle),+)
+                .$memchrfind($hay_start, $hay_end)
+        }
+
+        #[cfg(target_feature = "sse2")]
+        #[target_feature(enable = "sse2")]
+        unsafe fn find_sse2(
+            $($needle: u8),+,
+            $hay_start: *const u8,
+            $hay_end: *const u8,
+        ) -> $retty {
+            use crate::arch::x86_64::sse2::memchr::$memchrty;
+            $memchrty::new_unchecked($($needle),+)
+                .$memchrfind($hay_start, $hay_end)
+        }
+
+        unsafe fn find_fallback(
+            $($needle: u8),+,
+            $hay_start: *const u8,
+            $hay_end: *const u8,
+        ) -> $retty {
+            use crate::arch::all::memchr::$memchrty;
+            $memchrty::new($($needle),+).$memchrfind($hay_start, $hay_end)
+        }
+
+        unsafe fn detect(
+            $($needle: u8),+,
+            $hay_start: *const u8,
+            $hay_end: *const u8,
+        ) -> $retty {
+            let fun = {
+                #[cfg(not(target_feature = "sse2"))]
+                {
+                    debug!(
+                        "no sse2 feature available, using fallback for {}",
+                        stringify!($memchrty),
+                    );
+                    find_fallback as RealFn
+                }
+                #[cfg(target_feature = "sse2")]
+                {
+                    use crate::arch::x86_64::{sse2, avx2};
+                    if avx2::memchr::$memchrty::is_available() {
+                        debug!("chose AVX2 for {}", stringify!($memchrty));
+                        find_avx2 as RealFn
+                    } else if sse2::memchr::$memchrty::is_available() {
+                        debug!("chose SSE2 for {}", stringify!($memchrty));
+                        find_sse2 as RealFn
+                    } else {
+                        debug!("chose fallback for {}", stringify!($memchrty));
+                        find_fallback as RealFn
+                    }
+                }
+            };
+            FN.store(fun as Fn, Ordering::Relaxed);
+            // SAFETY: The only thing we need to uphold here is the
+            // `#[target_feature]` requirements. Since we check is_available
+            // above before using the corresponding implementation, we are
+            // guaranteed to only call code that is supported on the current
+            // CPU.
+            fun($($needle),+, $hay_start, $hay_end)
+        }
+
+        // SAFETY: By virtue of the caller contract, RealFn is a function
+        // pointer, which is always safe to transmute with a *mut (). Also,
+        // since we use $memchrty::is_available, it is guaranteed to be safe
+        // to call $memchrty::$memchrfind.
+        unsafe {
+            let fun = FN.load(Ordering::Relaxed);
+            core::mem::transmute::<Fn, RealFn>(fun)(
+                $($needle),+,
+                $hay_start,
+                $hay_end,
+            )
+        }
+    }};
+}
+
+// The routines below dispatch to AVX2, SSE2 or a fallback routine based on
+// what's available in the current environment. The secret sauce here is that
+// we only check for which one to use approximately once, and then "cache" that
+// choice into a global function pointer. Subsequent invocations then just call
+// the appropriate function directly.
+
+/// memchr, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::find_raw`.
+#[inline(always)]
+pub(crate) fn memchr_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    // SAFETY: We provide a valid function pointer type.
+    unsafe_ifunc!(
+        One,
+        find_raw,
+        unsafe fn(u8, *const u8, *const u8) -> Option<*const u8>,
+        Option<*const u8>,
+        start,
+        end,
+        n1
+    )
+}
+
+/// memrchr, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::rfind_raw`.
+#[inline(always)]
+pub(crate) fn memrchr_raw(
+    n1: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    // SAFETY: We provide a valid function pointer type.
+    unsafe_ifunc!(
+        One,
+        rfind_raw,
+        unsafe fn(u8, *const u8, *const u8) -> Option<*const u8>,
+        Option<*const u8>,
+        start,
+        end,
+        n1
+    )
+}
+
+/// memchr2, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Two::find_raw`.
+#[inline(always)]
+pub(crate) fn memchr2_raw(
+    n1: u8,
+    n2: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    // SAFETY: We provide a valid function pointer type.
+    unsafe_ifunc!(
+        Two,
+        find_raw,
+        unsafe fn(u8, u8, *const u8, *const u8) -> Option<*const u8>,
+        Option<*const u8>,
+        start,
+        end,
+        n1,
+        n2
+    )
+}
+
+/// memrchr2, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Two::rfind_raw`.
+#[inline(always)]
+pub(crate) fn memrchr2_raw(
+    n1: u8,
+    n2: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    // SAFETY: We provide a valid function pointer type.
+    unsafe_ifunc!(
+        Two,
+        rfind_raw,
+        unsafe fn(u8, u8, *const u8, *const u8) -> Option<*const u8>,
+        Option<*const u8>,
+        start,
+        end,
+        n1,
+        n2
+    )
+}
+
+/// memchr3, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Three::find_raw`.
+#[inline(always)]
+pub(crate) fn memchr3_raw(
+    n1: u8,
+    n2: u8,
+    n3: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    // SAFETY: We provide a valid function pointer type.
+    unsafe_ifunc!(
+        Three,
+        find_raw,
+        unsafe fn(u8, u8, u8, *const u8, *const u8) -> Option<*const u8>,
+        Option<*const u8>,
+        start,
+        end,
+        n1,
+        n2,
+        n3
+    )
+}
+
+/// memrchr3, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `Three::rfind_raw`.
+#[inline(always)]
+pub(crate) fn memrchr3_raw(
+    n1: u8,
+    n2: u8,
+    n3: u8,
+    start: *const u8,
+    end: *const u8,
+) -> Option<*const u8> {
+    // SAFETY: We provide a valid function pointer type.
+    unsafe_ifunc!(
+        Three,
+        rfind_raw,
+        unsafe fn(u8, u8, u8, *const u8, *const u8) -> Option<*const u8>,
+        Option<*const u8>,
+        start,
+        end,
+        n1,
+        n2,
+        n3
+    )
+}
+
+/// Count all matching bytes, but using raw pointers to represent the haystack.
+///
+/// # Safety
+///
+/// Pointers must be valid. See `One::count_raw`.
+#[inline(always)]
+pub(crate) fn count_raw(n1: u8, start: *const u8, end: *const u8) -> usize {
+    // SAFETY: We provide a valid function pointer type.
+    unsafe_ifunc!(
+        One,
+        count_raw,
+        unsafe fn(u8, *const u8, *const u8) -> usize,
+        usize,
+        start,
+        end,
+        n1
+    )
+}
diff --git a/vendor/memchr/src/arch/x86_64/mod.rs b/vendor/memchr/src/arch/x86_64/mod.rs
new file mode 100644
index 0000000..5dad721
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/mod.rs
@@ -0,0 +1,8 @@
+/*!
+Vector algorithms for the `x86_64` target.
+*/
+
+pub mod avx2;
+pub mod sse2;
+
+pub(crate) mod memchr;
diff --git a/vendor/memchr/src/arch/x86_64/sse2/memchr.rs b/vendor/memchr/src/arch/x86_64/sse2/memchr.rs
new file mode 100644
index 0000000..c6f75df
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/sse2/memchr.rs
@@ -0,0 +1,1077 @@
+/*!
+This module defines 128-bit vector implementations of `memchr` and friends.
+
+The main types in this module are [`One`], [`Two`] and [`Three`]. They are for
+searching for one, two or three distinct bytes, respectively, in a haystack.
+Each type also has corresponding double ended iterators. These searchers are
+typically much faster than scalar routines accomplishing the same task.
+
+The `One` searcher also provides a [`One::count`] routine for efficiently
+counting the number of times a single byte occurs in a haystack. This is
+useful, for example, for counting the number of lines in a haystack. This
+routine exists because it is usually faster, especially with a high match
+count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its
+`Iterator::count` implementation to use this routine.)
+
+Only one, two and three bytes are supported because three bytes is about
+the point where one sees diminishing returns. Beyond this point and it's
+probably (but not necessarily) better to just use a simple `[bool; 256]` array
+or similar. However, it depends mightily on the specific work-load and the
+expected match frequency.
+*/
+
+use core::arch::x86_64::__m128i;
+
+use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector};
+
+/// Finds all occurrences of a single byte in a haystack.
+#[derive(Clone, Copy, Debug)]
+pub struct One(generic::One<__m128i>);
+
+impl One {
+    /// Create a new searcher that finds occurrences of the needle byte given.
+    ///
+    /// This particular searcher is specialized to use SSE2 vector instructions
+    /// that typically make it quite fast.
+    ///
+    /// If SSE2 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle: u8) -> Option<One> {
+        if One::is_available() {
+            // SAFETY: we check that sse2 is available above.
+            unsafe { Some(One::new_unchecked(needle)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to SSE2 vectors and routines without
+    /// checking that SSE2 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `sse2` instructions
+    /// in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to SSE2
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle: u8) -> One {
+        One(generic::One::new(needle))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`One::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `One::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "sse2")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Counts all occurrences of this byte in the given haystack.
+    #[inline]
+    pub fn count(&self, haystack: &[u8]) -> usize {
+        // SAFETY: All of our pointers are derived directly from a borrowed
+        // slice, which is guaranteed to be valid.
+        unsafe {
+            let start = haystack.as_ptr();
+            let end = start.add(haystack.len());
+            self.count_raw(start, end)
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < __m128i::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'sse2' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        //
+        // Note that we could call `self.0.find_raw` directly here. But that
+        // means we'd have to annotate this routine with `target_feature`.
+        // Which is fine, because this routine is `unsafe` anyway and the
+        // `target_feature` obligation is met by virtue of building a `One`.
+        // The real problem is that a routine with a `target_feature`
+        // annotation generally can't be inlined into caller code unless the
+        // caller code has the same target feature annotations. Which is maybe
+        // okay for SSE2, but we do the same thing for AVX2 where caller code
+        // probably usually doesn't have AVX2 enabled. That means that this
+        // routine can be inlined which will handle some of the short-haystack
+        // cases above without touching the architecture specific code.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < __m128i::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'sse2' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        //
+        // See note in forward routine above for why we don't just call
+        // `self.0.rfind_raw` directly here.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Counts all occurrences of this byte in the given haystack represented
+    /// by raw pointers.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `0` will always be returned.
+    #[inline]
+    pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize {
+        if start >= end {
+            return 0;
+        }
+        if end.distance(start) < __m128i::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::count_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+            });
+        }
+        // SAFETY: Building a `One` means it's safe to call 'sse2' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        self.count_raw_impl(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Execute a count using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`One::count_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `One`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn count_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> usize {
+        self.0.count_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> {
+        OneIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of a single byte in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`One::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`One`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct OneIter<'a, 'h> {
+    searcher: &'a One,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for OneIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn count(self) -> usize {
+        self.it.count(|s, e| {
+            // SAFETY: We rely on our generic iterator to return valid start
+            // and end pointers.
+            unsafe { self.searcher.count_raw(s, e) }
+        })
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {}
+
+/// Finds all occurrences of two bytes in a haystack.
+///
+/// That is, this reports matches of one of two possible bytes. For example,
+/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`,
+/// `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Two(generic::Two<__m128i>);
+
+impl Two {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use SSE2 vector instructions
+    /// that typically make it quite fast.
+    ///
+    /// If SSE2 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8) -> Option<Two> {
+        if Two::is_available() {
+            // SAFETY: we check that sse2 is available above.
+            unsafe { Some(Two::new_unchecked(needle1, needle2)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to SSE2 vectors and routines without
+    /// checking that SSE2 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `sse2` instructions
+    /// in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to SSE2
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two {
+        Two(generic::Two::new(needle1, needle2))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Two::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Two::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "sse2")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < __m128i::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1() || b == self.0.needle2()
+            });
+        }
+        // SAFETY: Building a `Two` means it's safe to call 'sse2' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        //
+        // Note that we could call `self.0.find_raw` directly here. But that
+        // means we'd have to annotate this routine with `target_feature`.
+        // Which is fine, because this routine is `unsafe` anyway and the
+        // `target_feature` obligation is met by virtue of building a `Two`.
+        // The real problem is that a routine with a `target_feature`
+        // annotation generally can't be inlined into caller code unless the
+        // caller code has the same target feature annotations. Which is maybe
+        // okay for SSE2, but we do the same thing for AVX2 where caller code
+        // probably usually doesn't have AVX2 enabled. That means that this
+        // routine can be inlined which will handle some of the short-haystack
+        // cases above without touching the architecture specific code.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < __m128i::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1() || b == self.0.needle2()
+            });
+        }
+        // SAFETY: Building a `Two` means it's safe to call 'sse2' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        //
+        // See note in forward routine above for why we don't just call
+        // `self.0.rfind_raw` directly here.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Two::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Two`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle bytes in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> {
+        TwoIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of two possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Two::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Two`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct TwoIter<'a, 'h> {
+    searcher: &'a Two,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for TwoIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {}
+
+/// Finds all occurrences of three bytes in a haystack.
+///
+/// That is, this reports matches of one of three possible bytes. For example,
+/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets
+/// `0`, `2`, `3`, `4` and `5`.
+#[derive(Clone, Copy, Debug)]
+pub struct Three(generic::Three<__m128i>);
+
+impl Three {
+    /// Create a new searcher that finds occurrences of the needle bytes given.
+    ///
+    /// This particular searcher is specialized to use SSE2 vector instructions
+    /// that typically make it quite fast.
+    ///
+    /// If SSE2 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> {
+        if Three::is_available() {
+            // SAFETY: we check that sse2 is available above.
+            unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new finder specific to SSE2 vectors and routines without
+    /// checking that SSE2 is available.
+    ///
+    /// # Safety
+    ///
+    /// Callers must guarantee that it is safe to execute `sse2` instructions
+    /// in the current environment.
+    ///
+    /// Note that it is a common misconception that if one compiles for an
+    /// `x86_64` target, then they therefore automatically have access to SSE2
+    /// instructions. While this is almost always the case, it isn't true in
+    /// 100% of cases.
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    pub unsafe fn new_unchecked(
+        needle1: u8,
+        needle2: u8,
+        needle3: u8,
+    ) -> Three {
+        Three(generic::Three::new(needle1, needle2, needle3))
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Three::new`] will return
+    /// a `Some` value. Similarly, when it is false, it is guaranteed that
+    /// `Three::new` will return a `None` value.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(target_feature = "sse2")]
+        {
+            true
+        }
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+    }
+
+    /// Return the first occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn find(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `find_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.find_raw(s, e)
+            })
+        }
+    }
+
+    /// Return the last occurrence of one of the needle bytes in the given
+    /// haystack. If no such occurrence exists, then `None` is returned.
+    ///
+    /// The occurrence is reported as an offset into `haystack`. Its maximum
+    /// value is `haystack.len() - 1`.
+    #[inline]
+    pub fn rfind(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it
+        // falls within the bounds of the start and end pointers.
+        unsafe {
+            generic::search_slice_with_raw(haystack, |s, e| {
+                self.rfind_raw(s, e)
+            })
+        }
+    }
+
+    /// Like `find`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn find_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < __m128i::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::fwd_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+                    || b == self.0.needle2()
+                    || b == self.0.needle3()
+            });
+        }
+        // SAFETY: Building a `Three` means it's safe to call 'sse2' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        //
+        // Note that we could call `self.0.find_raw` directly here. But that
+        // means we'd have to annotate this routine with `target_feature`.
+        // Which is fine, because this routine is `unsafe` anyway and the
+        // `target_feature` obligation is met by virtue of building a `Three`.
+        // The real problem is that a routine with a `target_feature`
+        // annotation generally can't be inlined into caller code unless the
+        // caller code has the same target feature annotations. Which is maybe
+        // okay for SSE2, but we do the same thing for AVX2 where caller code
+        // probably usually doesn't have AVX2 enabled. That means that this
+        // routine can be inlined which will handle some of the short-haystack
+        // cases above without touching the architecture specific code.
+        self.find_raw_impl(start, end)
+    }
+
+    /// Like `rfind`, but accepts and returns raw pointers.
+    ///
+    /// When a match is found, the pointer returned is guaranteed to be
+    /// `>= start` and `< end`.
+    ///
+    /// This routine is useful if you're already using raw pointers and would
+    /// like to avoid converting back to a slice before executing a search.
+    ///
+    /// # Safety
+    ///
+    /// * Both `start` and `end` must be valid for reads.
+    /// * Both `start` and `end` must point to an initialized value.
+    /// * Both `start` and `end` must point to the same allocated object and
+    /// must either be in bounds or at most one byte past the end of the
+    /// allocated object.
+    /// * Both `start` and `end` must be _derived from_ a pointer to the same
+    /// object.
+    /// * The distance between `start` and `end` must not overflow `isize`.
+    /// * The distance being in bounds must not rely on "wrapping around" the
+    /// address space.
+    ///
+    /// Note that callers may pass a pair of pointers such that `start >= end`.
+    /// In that case, `None` will always be returned.
+    #[inline]
+    pub unsafe fn rfind_raw(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        if start >= end {
+            return None;
+        }
+        if end.distance(start) < __m128i::BYTES {
+            // SAFETY: We require the caller to pass valid start/end pointers.
+            return generic::rev_byte_by_byte(start, end, |b| {
+                b == self.0.needle1()
+                    || b == self.0.needle2()
+                    || b == self.0.needle3()
+            });
+        }
+        // SAFETY: Building a `Three` means it's safe to call 'sse2' routines.
+        // Also, we've checked that our haystack is big enough to run on the
+        // vector routine. Pointer validity is caller's responsibility.
+        //
+        // See note in forward routine above for why we don't just call
+        // `self.0.rfind_raw` directly here.
+        self.rfind_raw_impl(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::find_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.find_raw(start, end)
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as [`Three::rfind_raw`], except the distance between `start` and
+    /// `end` must be at least the size of an SSE2 vector (in bytes).
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Three`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn rfind_raw_impl(
+        &self,
+        start: *const u8,
+        end: *const u8,
+    ) -> Option<*const u8> {
+        self.0.rfind_raw(start, end)
+    }
+
+    /// Returns an iterator over all occurrences of the needle byte in the
+    /// given haystack.
+    ///
+    /// The iterator returned implements `DoubleEndedIterator`. This means it
+    /// can also be used to find occurrences in reverse order.
+    #[inline]
+    pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> {
+        ThreeIter { searcher: self, it: generic::Iter::new(haystack) }
+    }
+}
+
+/// An iterator over all occurrences of three possible bytes in a haystack.
+///
+/// This iterator implements `DoubleEndedIterator`, which means it can also be
+/// used to find occurrences in reverse order.
+///
+/// This iterator is created by the [`Three::iter`] method.
+///
+/// The lifetime parameters are as follows:
+///
+/// * `'a` refers to the lifetime of the underlying [`Three`] searcher.
+/// * `'h` refers to the lifetime of the haystack being searched.
+#[derive(Clone, Debug)]
+pub struct ThreeIter<'a, 'h> {
+    searcher: &'a Three,
+    it: generic::Iter<'h>,
+}
+
+impl<'a, 'h> Iterator for ThreeIter<'a, 'h> {
+    type Item = usize;
+
+    #[inline]
+    fn next(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'find_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) }
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.it.size_hint()
+    }
+}
+
+impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> {
+    #[inline]
+    fn next_back(&mut self) -> Option<usize> {
+        // SAFETY: We rely on the generic iterator to provide valid start
+        // and end pointers, but we guarantee that any pointer returned by
+        // 'rfind_raw' falls within the bounds of the start and end pointer.
+        unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) }
+    }
+}
+
+impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    define_memchr_quickcheck!(super);
+
+    #[test]
+    fn forward_one() {
+        crate::tests::memchr::Runner::new(1).forward_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_one() {
+        crate::tests::memchr::Runner::new(1).reverse_iter(
+            |haystack, needles| {
+                Some(One::new(needles[0])?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn count_one() {
+        crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| {
+            Some(One::new(needles[0])?.iter(haystack).count())
+        })
+    }
+
+    #[test]
+    fn forward_two() {
+        crate::tests::memchr::Runner::new(2).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_two() {
+        crate::tests::memchr::Runner::new(2).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                Some(Two::new(n1, n2)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+
+    #[test]
+    fn forward_three() {
+        crate::tests::memchr::Runner::new(3).forward_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).collect())
+            },
+        )
+    }
+
+    #[test]
+    fn reverse_three() {
+        crate::tests::memchr::Runner::new(3).reverse_iter(
+            |haystack, needles| {
+                let n1 = needles.get(0).copied()?;
+                let n2 = needles.get(1).copied()?;
+                let n3 = needles.get(2).copied()?;
+                Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect())
+            },
+        )
+    }
+}
diff --git a/vendor/memchr/src/arch/x86_64/sse2/mod.rs b/vendor/memchr/src/arch/x86_64/sse2/mod.rs
new file mode 100644
index 0000000..bcb8307
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/sse2/mod.rs
@@ -0,0 +1,6 @@
+/*!
+Algorithms for the `x86_64` target using 128-bit vectors via SSE2.
+*/
+
+pub mod memchr;
+pub mod packedpair;
diff --git a/vendor/memchr/src/arch/x86_64/sse2/packedpair.rs b/vendor/memchr/src/arch/x86_64/sse2/packedpair.rs
new file mode 100644
index 0000000..c8b5b99
--- /dev/null
+++ b/vendor/memchr/src/arch/x86_64/sse2/packedpair.rs
@@ -0,0 +1,232 @@
+/*!
+A 128-bit vector implementation of the "packed pair" SIMD algorithm.
+
+The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main
+difference is that it (by default) uses a background distribution of byte
+frequencies to heuristically select the pair of bytes to search for.
+
+[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last
+*/
+
+use core::arch::x86_64::__m128i;
+
+use crate::arch::{all::packedpair::Pair, generic::packedpair};
+
+/// A "packed pair" finder that uses 128-bit vector operations.
+///
+/// This finder picks two bytes that it believes have high predictive power
+/// for indicating an overall match of a needle. Depending on whether
+/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets
+/// where the needle matches or could match. In the prefilter case, candidates
+/// are reported whenever the [`Pair`] of bytes given matches.
+#[derive(Clone, Copy, Debug)]
+pub struct Finder(packedpair::Finder<__m128i>);
+
+impl Finder {
+    /// Create a new pair searcher. The searcher returned can either report
+    /// exact matches of `needle` or act as a prefilter and report candidate
+    /// positions of `needle`.
+    ///
+    /// If SSE2 is unavailable in the current environment or if a [`Pair`]
+    /// could not be constructed from the needle given, then `None` is
+    /// returned.
+    #[inline]
+    pub fn new(needle: &[u8]) -> Option<Finder> {
+        Finder::with_pair(needle, Pair::new(needle)?)
+    }
+
+    /// Create a new "packed pair" finder using the pair of bytes given.
+    ///
+    /// This constructor permits callers to control precisely which pair of
+    /// bytes is used as a predicate.
+    ///
+    /// If SSE2 is unavailable in the current environment, then `None` is
+    /// returned.
+    #[inline]
+    pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> {
+        if Finder::is_available() {
+            // SAFETY: we check that sse2 is available above. We are also
+            // guaranteed to have needle.len() > 1 because we have a valid
+            // Pair.
+            unsafe { Some(Finder::with_pair_impl(needle, pair)) }
+        } else {
+            None
+        }
+    }
+
+    /// Create a new `Finder` specific to SSE2 vectors and routines.
+    ///
+    /// # Safety
+    ///
+    /// Same as the safety for `packedpair::Finder::new`, and callers must also
+    /// ensure that SSE2 is available.
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder {
+        let finder = packedpair::Finder::<__m128i>::new(needle, pair);
+        Finder(finder)
+    }
+
+    /// Returns true when this implementation is available in the current
+    /// environment.
+    ///
+    /// When this is true, it is guaranteed that [`Finder::with_pair`] will
+    /// return a `Some` value. Similarly, when it is false, it is guaranteed
+    /// that `Finder::with_pair` will return a `None` value. Notice that this
+    /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely,
+    /// even when `Finder::is_available` is true, it is not guaranteed that a
+    /// valid [`Pair`] can be found from the needle given.
+    ///
+    /// Note also that for the lifetime of a single program, if this returns
+    /// true then it will always return true.
+    #[inline]
+    pub fn is_available() -> bool {
+        #[cfg(not(target_feature = "sse2"))]
+        {
+            false
+        }
+        #[cfg(target_feature = "sse2")]
+        {
+            true
+        }
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> {
+        // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines.
+        unsafe { self.find_impl(haystack, needle) }
+    }
+
+    /// Run this finder on the given haystack as a prefilter.
+    ///
+    /// If a candidate match is found, then an offset where the needle *could*
+    /// begin in the haystack is returned.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    #[inline]
+    pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> {
+        // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines.
+        unsafe { self.find_prefilter_impl(haystack) }
+    }
+
+    /// Execute a search using SSE2 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_impl(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        self.0.find(haystack, needle)
+    }
+
+    /// Execute a prefilter search using SSE2 vectors and routines.
+    ///
+    /// # Panics
+    ///
+    /// When `haystack.len()` is less than [`Finder::min_haystack_len`].
+    ///
+    /// # Safety
+    ///
+    /// (The target feature safety obligation is automatically fulfilled by
+    /// virtue of being a method on `Finder`, which can only be constructed
+    /// when it is safe to call `sse2` routines.)
+    #[target_feature(enable = "sse2")]
+    #[inline]
+    unsafe fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> {
+        self.0.find_prefilter(haystack)
+    }
+
+    /// Returns the pair of offsets (into the needle) used to check as a
+    /// predicate before confirming whether a needle exists at a particular
+    /// position.
+    #[inline]
+    pub fn pair(&self) -> &Pair {
+        self.0.pair()
+    }
+
+    /// Returns the minimum haystack length that this `Finder` can search.
+    ///
+    /// Using a haystack with length smaller than this in a search will result
+    /// in a panic. The reason for this restriction is that this finder is
+    /// meant to be a low-level component that is part of a larger substring
+    /// strategy. In that sense, it avoids trying to handle all cases and
+    /// instead only handles the cases that it can handle very well.
+    #[inline]
+    pub fn min_haystack_len(&self) -> usize {
+        self.0.min_haystack_len()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> {
+        let f = Finder::new(needle)?;
+        if haystack.len() < f.min_haystack_len() {
+            return None;
+        }
+        Some(f.find(haystack, needle))
+    }
+
+    define_substring_forward_quickcheck!(find);
+
+    #[test]
+    fn forward_substring() {
+        crate::tests::substring::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find(haystack, needle))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+
+    #[test]
+    fn forward_packedpair_prefilter() {
+        fn find(
+            haystack: &[u8],
+            needle: &[u8],
+            index1: u8,
+            index2: u8,
+        ) -> Option<Option<usize>> {
+            let pair = Pair::with_indices(needle, index1, index2)?;
+            let f = Finder::with_pair(needle, pair)?;
+            if haystack.len() < f.min_haystack_len() {
+                return None;
+            }
+            Some(f.find_prefilter(haystack))
+        }
+        crate::tests::packedpair::Runner::new().fwd(find).run()
+    }
+}