Bug 1475197 - Part 2: Update Cargo.lock and re-vendor Rust dependencies. r=emilio
☠☠ backed out by 129b25a6bcfd ☠ ☠
authorCameron McCormack <cam@mcc.id.au>
Tue, 17 Jul 2018 12:15:08 +1000
changeset 486156 108e22d963cb5fe47634fd33f1d5a787920c4eb1
parent 486155 4bd5f858842255dfcc1cbe918314de324ecb2fbc
child 486157 129b25a6bcfd65ef7e096d445faebdc63781ee1c
push id1815
push userffxbld-merge
push dateMon, 15 Oct 2018 10:40:45 +0000
treeherdermozilla-release@18d4c09e9378 [default view] [failures only]
perfherder[talos] [build metrics] [platform microbench] (compared to previous push)
reviewersemilio
bugs1475197
milestone63.0a1
first release with
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
last release without
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
Bug 1475197 - Part 2: Update Cargo.lock and re-vendor Rust dependencies. r=emilio MozReview-Commit-ID: GHrD4b8xvcC
Cargo.lock
third_party/rust/thin-slice/.cargo-checksum.json
third_party/rust/thin-slice/Cargo.toml
third_party/rust/thin-slice/README.md
third_party/rust/thin-slice/src/lib.rs
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1146,16 +1146,17 @@ dependencies = [
  "app_units 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.24.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.18.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hashglobe 0.1.0",
  "selectors 0.19.0",
  "servo_arc 0.1.1",
  "smallbitvec 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thin-slice 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "malloc_size_of_derive"
 version = "0.0.1"
 dependencies = [
  "quote 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1815,16 +1816,17 @@ dependencies = [
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf_codegen 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "precomputed-hash 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_arc 0.1.1",
  "smallvec 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thin-slice 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "semver"
 version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1982,16 +1984,17 @@ dependencies = [
  "rayon 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "selectors 0.19.0",
  "servo_arc 0.1.1",
  "smallbitvec 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "style_derive 0.0.1",
  "style_traits 0.0.1",
+ "thin-slice 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "uluru 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-bidi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-segmentation 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "walkdir 2.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2112,16 +2115,21 @@ name = "textwrap"
 version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "term_size 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-width 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "thin-slice"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "thread_local"
 version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "lazy_static 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2732,16 +2740,17 @@ dependencies = [
 "checksum syn 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)" = "91b52877572087400e83d24b9178488541e3d535259e04ff17a63df1e5ceff59"
 "checksum syn 0.14.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c67da57e61ebc7b7b6fff56bb34440ca3a83db037320b0507af4c10368deda7d"
 "checksum synstructure 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "98cad891cd238c98e1f0aec9f7c0f620aa696e4e5f7daba56ac67b5e86a6b049"
 "checksum tempdir 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "87974a6f5c1dfb344d733055601650059a3363de2a6104819293baff662132d6"
 "checksum term 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "fa63644f74ce96fbeb9b794f66aff2a52d601cbd5e80f4b97123e3899f4570f1"
 "checksum term_size 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2b6b55df3198cc93372e85dd2ed817f0e38ce8cc0f22eb32391bfad9c4bf209"
 "checksum termcolor 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "adc4587ead41bf016f11af03e55a624c06568b5a19db4e90fde573d805074f83"
 "checksum textwrap 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c0b59b6b4b44d867f1370ef1bd91bfb262bf07bf0ae65c202ea2fbc16153b693"
+"checksum thin-slice 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "85b3e41c2cf31e81a7ec4ad3acd69abde19887e0f7f8e74dcdedc8cb7b158ef8"
 "checksum thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "279ef31c19ededf577bfd12dfae728040a21f635b06a24cd670ff510edd38963"
 "checksum thread_profiler 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf947d192a9be60ef5131cc7a4648886ba89d712f16700ebbf80c8a69d05d48f"
 "checksum time 0.1.40 (registry+https://github.com/rust-lang/crates.io-index)" = "d825be0eb33fda1a7e68012d51e9c7f451dc1a69391e7fdc197060bb8c56667b"
 "checksum tokio-core 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "febd81b3e2ef615c6c8077347b33f3f3deec3d708ecd08194c9707b7a1eccfc9"
 "checksum tokio-io 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b4ab83e7adb5677e42e405fa4ceff75659d93c4d7d7dd22f52fcec59ee9f02af"
 "checksum tokio-uds 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "65ae5d255ce739e8537221ed2942e0445f4b3b813daebac1c0050ddaaa3587f9"
 "checksum toml 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "a7540f4ffc193e0d3c94121edb19b055670d369f77d5804db11ae053a45b6e7e"
 "checksum traitobject 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "efd1f82c56340fdf16f2a953d7bda4f8fdffba13d93b00844c25572110b26079"
new file mode 100644
--- /dev/null
+++ b/third_party/rust/thin-slice/.cargo-checksum.json
@@ -0,0 +1,1 @@
+{"files":{"Cargo.toml":"4e814457b6228f1d617315305eeda7c1d4f3510074c394a44858daced98438af","README.md":"7bbdabe6f919f88d407a9b6361bd75bd43d09c533631776ae2db1851f93a77af","src/lib.rs":"5b1f2bfc9edfc6036a8880cde88f862931eec5036e6cf63690f82921053b29fe"},"package":"85b3e41c2cf31e81a7ec4ad3acd69abde19887e0f7f8e74dcdedc8cb7b158ef8"}
\ No newline at end of file
new file mode 100644
--- /dev/null
+++ b/third_party/rust/thin-slice/Cargo.toml
@@ -0,0 +1,23 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g. crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+name = "thin-slice"
+version = "0.1.0"
+authors = ["Cameron McCormack <cam@mcc.id.au>"]
+description = "An owned slice that packs the slice storage into a single word when possible"
+readme = "README.md"
+keywords = ["slice", "tagged", "pointer"]
+license = "MPL-2.0"
+repository = "https://github.com/heycam/thin-slice"
+
+[dependencies]
new file mode 100644
--- /dev/null
+++ b/third_party/rust/thin-slice/README.md
@@ -0,0 +1,45 @@
+# thin-slice
+
+An owned slice that packs the slice storage into a single word when possible.
+
+## Usage
+
+```rust
+extern crate thin_slice;
+
+struct Ticket {
+    numbers: Box<[u8]>,
+    winning: bool,
+}
+
+struct ThinTicket {
+    numbers: ThinBoxedSlice<u8>,
+    winning: bool,
+}
+
+fn main() {
+    let nums = vec![4, 8, 15, 16, 23, 42].into_boxed_slice();
+    let ticket = ThinTicket {
+        numbers: nums.into(),
+        winning: false,
+    };
+    println!("Numbers: {:?}", ticket.numbers);
+
+    println!("size_of::<usize>():      {}", mem::size_of::<usize>());
+    println!("size_of::<Ticket>():     {}", mem::size_of::<Ticket>());
+    println!("size_of::<ThinTicket>(): {}", mem::size_of::<ThinTicket>());
+}
+```
+
+Output on `x86_64`:
+
+```
+size_of::<usize>():      8
+size_of::<Ticket>():     24
+size_of::<ThinTicket>(): 16
+```
+
+## License
+
+thin-slice is distributed under the terms of the
+[Mozilla Public License, v. 2.0](https://www.mozilla.org/MPL/2.0/).
new file mode 100644
--- /dev/null
+++ b/third_party/rust/thin-slice/src/lib.rs
@@ -0,0 +1,544 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! An owned slice that tries to use only one word of storage.
+//!
+//! `ThinBoxedSlice<T>` can be used in place of `Box<[T]>` on the `x86_64`
+//! architecture to hold ownership of a slice when it's important to reduce
+//! memory usage of the box itself. When the slice length is less than
+//! `0xffff`, a single word is used to encode the slice pointer and length.
+//! When it is greater than `0xffff`, a heap allocation is used to store the
+//! fat pointer representing the slice.
+//!
+//! A `ThinBoxedSlice<T>` is always created by converting from a `Box<[T]>`.
+//!
+//! On any architecture other than `x86_64`, a `ThinBoxedSlice<T>` will simply
+//! use a `Box<[T]>` internally.
+//!
+//! # Examples
+//!
+//! Creating a `ThinBoxedSlice`:
+//!
+//! ```
+//! # use thin_slice::ThinBoxedSlice;
+//! let fat_pointer = vec![10, 20, 30].into_boxed_slice();
+//! let thin_pointer: ThinBoxedSlice<_> = fat_pointer.into();
+//! ```
+
+use std::cmp::Ordering;
+use std::fmt;
+use std::hash::{Hash, Hasher};
+#[cfg(target_arch = "x86_64")]
+use std::marker::PhantomData;
+#[cfg(target_arch = "x86_64")]
+use std::mem;
+use std::ops::{Deref, DerefMut};
+#[cfg(target_arch = "x86_64")]
+use std::ptr::NonNull;
+#[cfg(target_arch = "x86_64")]
+use std::slice;
+
+/// An owned slice that tries to use only one word of storage.
+///
+/// See the [module-level documentation](index.html) for more.
+pub struct ThinBoxedSlice<T> {
+    /// Storage for the slice.
+    ///
+    /// Once `std::num::NonZeroUsize` has stabilized, we can switch to that.
+    ///
+    /// The value stored here depends on the length of the slice.
+    ///
+    /// If len = 0, `data` will be `1usize`.
+    ///
+    /// If 0 < len < 0xffff, then len will be stored in the top 16 bits of
+    /// data, and the lower 48 bits will be the pointer to the elements.
+    ///
+    /// If len >= 0xffff, then the top 16 bits of data will be 0xffff, and
+    /// the lower 48 bits will be a pointer to a heap allocated `Box<[T]>`.
+    #[cfg(target_arch = "x86_64")]
+    data: NonNull<()>,
+
+    #[cfg(not(target_arch = "x86_64"))]
+    data: Box<[T]>,
+
+    #[cfg(target_arch = "x86_64")]
+    _phantom: PhantomData<Box<[T]>>,
+}
+
+#[cfg(target_arch = "x86_64")]
+const TAG_MASK: usize = 0xffff000000000000;
+
+#[cfg(target_arch = "x86_64")]
+const PTR_MASK: usize = 0x0000ffffffffffff;
+
+#[cfg(target_arch = "x86_64")]
+const PTR_HIGH: usize = 0x0000800000000000;
+
+#[cfg(target_arch = "x86_64")]
+const TAG_SHIFT: usize = 48;
+
+#[cfg(target_arch = "x86_64")]
+const TAG_LIMIT: usize = TAG_MASK >> TAG_SHIFT;
+
+#[cfg(target_arch = "x86_64")]
+enum Storage<T> {
+    Inline(*mut T, usize),
+    Spilled(*mut Box<[T]>),
+}
+
+#[cfg(target_arch = "x86_64")]
+impl<T> ThinBoxedSlice<T> {
+    /// Constructs a `ThinBoxedSlice` from a raw pointer.
+    ///
+    /// Like `Box::from_raw`, after calling this function, the raw pointer is
+    /// owned by the resulting `ThinBoxedSlice`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use thin_slice::ThinBoxedSlice;
+    /// let x = vec![10, 20, 30].into_boxed_slice();       // a Box<[i32]>
+    /// let ptr = Box::into_raw(x);                        // a *mut [i32]
+    /// let x = unsafe { ThinBoxedSlice::from_raw(ptr) };  // a ThinBoxedSlice<i32>
+    /// ```
+    #[inline]
+    pub unsafe fn from_raw(raw: *mut [T]) -> ThinBoxedSlice<T> {
+        let len = (*raw).len();
+        let ptr = (*raw).as_mut_ptr();
+        let storage = if len == 0 {
+            Storage::Inline(1usize as *mut _, 0)
+        } else if len < TAG_LIMIT {
+            Storage::Inline(ptr, len)
+        } else {
+            let boxed_slice = Box::from_raw(raw);
+            Storage::Spilled(Box::into_raw(Box::new(boxed_slice)))
+        };
+        ThinBoxedSlice {
+            data: storage.into_data(),
+            _phantom: PhantomData,
+        }
+    }
+
+    /// Consumes the `ThinBoxedSlice`, returning a raw pointer to the slice
+    /// it owned.
+    ///
+    /// Like `Box::into_raw`, after calling this function, the caller is
+    /// responsible for the memory previously managed by the `ThinBoxedSlice`.
+    /// In particular, the caller should properly destroy the `[T]` and release
+    /// the memory. The proper way to do so is to convert the raw pointer back
+    /// into a `Box` or a `ThinBoxedSlice`, with either the `Box::from_raw` or
+    /// `ThinBoxedSlice::from_raw` functions.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use thin_slice::ThinBoxedSlice;
+    /// let x = vec![10, 20, 30].into_boxed_slice();
+    /// let x = ThinBoxedSlice::from(x);
+    /// let ptr = ThinBoxedSlice::into_raw(x);
+    /// ```
+    #[inline]
+    pub fn into_raw(b: ThinBoxedSlice<T>) -> *mut [T] {
+        unsafe {
+            match b.into_storage() {
+                Storage::Inline(ptr, len) => {
+                    slice::from_raw_parts_mut(ptr, len)
+                }
+                Storage::Spilled(ptr) => {
+                    Box::into_raw(*Box::from_raw(ptr))
+                }
+            }
+        }
+    }
+
+    /// Consumes and leaks the `ThinBoxedSlice`, returning a mutable reference,
+    /// `&'a mut [T]`. Here, the lifetime `'a` may be chosen to be `'static`.
+    ///
+    /// Like `Box::leak`, this function is mainly useful for data that lives
+    /// for the remainder of the program's life. Dropping the returned
+    /// reference will cause a memory leak. If this is not acceptable, the
+    /// reference should first be wrapped with the `Box::from_raw` function
+    /// producing a `Box`, or with the `ThinBoxedSlice::from_raw` function
+    /// producing a `ThinBoxedSlice`. This value can then be dropped which will
+    /// properly destroy `[T]` and release the allocated memory.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use thin_slice::ThinBoxedSlice;
+    /// fn main() {
+    ///     let x = ThinBoxedSlice::from(vec![1, 2, 3].into_boxed_slice());
+    ///     let static_ref = ThinBoxedSlice::leak(x);
+    ///     static_ref[0] = 4;
+    ///     assert_eq!(*static_ref, [4, 2, 3]);
+    /// }
+    /// ```
+    #[inline]
+    pub fn leak(b: ThinBoxedSlice<T>) -> &'static mut [T] {
+        unsafe { &mut *ThinBoxedSlice::into_raw(b) }
+    }
+
+    /// Returns a pointer to the heap allocation that stores the fat pointer
+    /// to the slice, if any. This is useful for systems that need to measure
+    /// memory allocation, but is otherwise an opaque pointer.
+    #[inline]
+    pub fn spilled_storage(&self) -> Option<*const ()> {
+        match self.storage() {
+            Storage::Inline(..) => None,
+            Storage::Spilled(ptr) => Some(ptr as *const ()),
+        }
+    }
+
+    #[inline]
+    fn storage(&self) -> Storage<T> {
+        Storage::from_data(self.data.clone())
+    }
+
+    #[inline]
+    fn into_storage(self) -> Storage<T> {
+        let storage = self.storage();
+        mem::forget(self);
+        storage
+    }
+}
+
+#[cfg(not(target_arch = "x86_64"))]
+impl<T> ThinBoxedSlice<T> {
+    /// Constructs a `ThinBoxedSlice` from a raw pointer.
+    ///
+    /// Like `Box::from_raw`, after calling this function, the raw pointer is
+    /// owned by the resulting `ThinBoxedSlice`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use thin_slice::ThinBoxedSlice;
+    /// let x = vec![10, 20, 30].into_boxed_slice();       // a Box<[i32]>
+    /// let ptr = Box::into_raw(x);                        // a *mut [i32]
+    /// let x = unsafe { ThinBoxedSlice::from_raw(ptr) };  // a ThinBoxedSlice<i32>
+    /// ```
+    #[inline]
+    pub unsafe fn from_raw(raw: *mut [T]) -> ThinBoxedSlice<T> {
+        ThinBoxedSlice {
+            data: Box::from_raw(raw),
+        }
+    }
+
+    /// Consumes the `ThinBoxedSlice`, returning a raw pointer to the slice
+    /// it owned.
+    ///
+    /// Like `Box::into_raw`, after calling this function, the caller is
+    /// responsible for the memory previously managed by the `ThinBoxedSlice`.
+    /// In particular, the caller should properly destroy the `[T]` and release
+    /// the memory. The proper way to do so is to convert the raw pointer back
+    /// into a `Box` or a `ThinBoxedSlice`, with either the `Box::from_raw` or
+    /// `ThinBoxedSlice::from_raw` functions.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use thin_slice::ThinBoxedSlice;
+    /// let x = vec![10, 20, 30].into_boxed_slice();
+    /// let x = ThinBoxedSlice::from(x);
+    /// let ptr = ThinBoxedSlice::into_raw(x);
+    /// ```
+    #[inline]
+    pub fn into_raw(b: ThinBoxedSlice<T>) -> *mut [T] {
+        Box::into_raw(b.data)
+    }
+
+    /// Consumes and leaks the `ThinBoxedSlice`, returning a mutable reference,
+    /// `&'a mut [T]`. Here, the lifetime `'a` may be chosen to be `'static`.
+    ///
+    /// Like `Box::leak`, this function is mainly useful for data that lives
+    /// for the remainder of the program's life. Dropping the returned
+    /// reference will cause a memory leak. If this is not acceptable, the
+    /// reference should first be wrapped with the `Box::from_raw` function
+    /// producing a `Box`, or with the `ThinBoxedSlice::from_raw` function
+    /// producing a `ThinBoxedSlice`. This value can then be dropped which will
+    /// properly destroy `[T]` and release the allocated memory.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use thin_slice::ThinBoxedSlice;
+    /// fn main() {
+    ///     let x = ThinBoxedSlice::from(vec![1, 2, 3].into_boxed_slice());
+    ///     let static_ref = ThinBoxedSlice::leak(x);
+    ///     static_ref[0] = 4;
+    ///     assert_eq!(*static_ref, [4, 2, 3]);
+    /// }
+    /// ```
+    #[inline]
+    pub fn leak<'a>(b: ThinBoxedSlice<T>) -> &'a mut [T] where T: 'a {
+        Box::leak(b.data)
+    }
+
+    /// Returns a pointer to the heap allocation that stores the fat pointer
+    /// to the slice, if any. This is useful for systems that need to measure
+    /// memory allocation, but is otherwise an opaque pointer.
+    #[inline]
+    pub fn spilled_storage(&self) -> Option<*const ()> {
+        None
+    }
+}
+
+#[cfg(target_arch = "x86_64")]
+impl<T> Storage<T> {
+    #[inline]
+    fn from_data(data: NonNull<()>) -> Storage<T> {
+        let data = data.as_ptr() as usize;
+
+        let len = (data & TAG_MASK) >> TAG_SHIFT;
+        let mut ptr = data & PTR_MASK;
+
+        if (ptr & PTR_HIGH) == PTR_HIGH {
+            // Canonical linear addresses on x86_64 are sign extended from
+            // bit 48.
+            ptr |= TAG_MASK;
+        }
+
+        if len < TAG_LIMIT {
+            Storage::Inline(ptr as *mut T, len)
+        } else {
+            Storage::Spilled(ptr as *mut Box<[T]>)
+        }
+    }
+
+    #[inline]
+    fn into_data(self) -> NonNull<()> {
+        let data = match self {
+            Storage::Inline(ptr, len) => {
+                (len << TAG_SHIFT) | ((ptr as usize) & PTR_MASK)
+            }
+            Storage::Spilled(ptr) => {
+                TAG_MASK | ((ptr as usize) & PTR_MASK)
+            }
+        };
+        unsafe {
+            NonNull::new_unchecked(data as *mut _)
+        }
+    }
+}
+
+impl<T> From<Box<[T]>> for ThinBoxedSlice<T> {
+    fn from(value: Box<[T]>) -> ThinBoxedSlice<T> {
+        let ptr = Box::into_raw(value);
+        unsafe {
+            ThinBoxedSlice::from_raw(ptr)
+        }
+    }
+}
+
+impl<T> Into<Box<[T]>> for ThinBoxedSlice<T> {
+    fn into(self) -> Box<[T]> {
+        let ptr = ThinBoxedSlice::into_raw(self);
+        unsafe {
+            Box::from_raw(ptr)
+        }
+    }
+}
+
+unsafe impl<T: Send> Send for ThinBoxedSlice<T> {}
+unsafe impl<T: Sync> Sync for ThinBoxedSlice<T> {}
+
+#[cfg(target_arch = "x86_64")]
+impl<T> Drop for ThinBoxedSlice<T> {
+    fn drop(&mut self) {
+        let _ = Into::<Box<[T]>>::into(
+            ThinBoxedSlice {
+                data: self.data.clone(),
+                _phantom: PhantomData,
+            }
+        );
+    }
+}
+
+impl<T: Clone> Clone for ThinBoxedSlice<T> {
+    #[cfg(target_arch = "x86_64")]
+    fn clone(&self) -> Self {
+        unsafe {
+            match self.storage() {
+                Storage::Inline(ptr, len) => {
+                    slice::from_raw_parts_mut(ptr, len)
+                        .to_vec()
+                        .into_boxed_slice()
+                        .into()
+                }
+                Storage::Spilled(ptr) => {
+                    (*ptr).clone().into()
+                }
+            }
+        }
+    }
+
+    #[cfg(not(target_arch = "x86_64"))]
+    fn clone(&self) -> Self {
+        ThinBoxedSlice {
+            data: self.data.clone(),
+        }
+    }
+}
+
+impl<T> AsRef<[T]> for ThinBoxedSlice<T> {
+    fn as_ref(&self) -> &[T] {
+        &**self
+    }
+}
+
+impl<T> AsMut<[T]> for ThinBoxedSlice<T> {
+    fn as_mut(&mut self) -> &mut [T] {
+        &mut **self
+    }
+}
+
+impl<T> Deref for ThinBoxedSlice<T> {
+    type Target = [T];
+
+    #[cfg(target_arch = "x86_64")]
+    fn deref(&self) -> &[T] {
+        unsafe {
+            match self.storage() {
+                Storage::Inline(ptr, len) => {
+                    slice::from_raw_parts(ptr, len)
+                }
+                Storage::Spilled(ptr) => {
+                    &**ptr
+                }
+            }
+        }
+    }
+
+    #[cfg(not(target_arch = "x86_64"))]
+    fn deref(&self) -> &[T] {
+        &*self.data
+    }
+}
+
+impl<T> DerefMut for ThinBoxedSlice<T> {
+    #[cfg(target_arch = "x86_64")]
+    fn deref_mut(&mut self) -> &mut [T] {
+        unsafe {
+            match self.storage() {
+                Storage::Inline(ptr, len) => {
+                    slice::from_raw_parts_mut(ptr, len)
+                }
+                Storage::Spilled(ptr) => {
+                    &mut **ptr
+                }
+            }
+        }
+    }
+
+    #[cfg(not(target_arch = "x86_64"))]
+    fn deref_mut(&mut self) -> &mut [T] {
+        &mut *self.data
+    }
+}
+
+impl<T> Default for ThinBoxedSlice<T> {
+    fn default() -> Self {
+        Box::<[T]>::default().into()
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for ThinBoxedSlice<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(&**self, f)
+    }
+}
+
+impl<T: Eq> Eq for ThinBoxedSlice<T> {}
+
+impl<T: Hash> Hash for ThinBoxedSlice<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        (**self).hash(state);
+    }
+}
+
+impl<T: PartialEq> PartialEq for ThinBoxedSlice<T> {
+    #[inline]
+    fn eq(&self, other: &ThinBoxedSlice<T>) -> bool {
+        PartialEq::eq(&**self, &**other)
+    }
+    #[inline]
+    fn ne(&self, other: &ThinBoxedSlice<T>) -> bool {
+        PartialEq::ne(&**self, &**other)
+    }
+}
+
+impl<T: PartialOrd> PartialOrd for ThinBoxedSlice<T> {
+    #[inline]
+    fn partial_cmp(&self, other: &ThinBoxedSlice<T>) -> Option<Ordering> {
+        PartialOrd::partial_cmp(&**self, &**other)
+    }
+    #[inline]
+    fn lt(&self, other: &ThinBoxedSlice<T>) -> bool {
+        PartialOrd::lt(&**self, &**other)
+    }
+    #[inline]
+    fn le(&self, other: &ThinBoxedSlice<T>) -> bool {
+        PartialOrd::le(&**self, &**other)
+    }
+    #[inline]
+    fn ge(&self, other: &ThinBoxedSlice<T>) -> bool {
+        PartialOrd::ge(&**self, &**other)
+    }
+    #[inline]
+    fn gt(&self, other: &ThinBoxedSlice<T>) -> bool {
+        PartialOrd::gt(&**self, &**other)
+    }
+}
+
+impl<T> fmt::Pointer for ThinBoxedSlice<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let ptr = &**self;
+        fmt::Pointer::fmt(&ptr, f)
+    }
+}
+
+#[cfg(target_arch = "x86_64")]
+#[test]
+fn test_spilled_storage() {
+    let x = ThinBoxedSlice::from(vec![0; TAG_LIMIT - 1].into_boxed_slice());
+    assert!(x.spilled_storage().is_none());
+
+    let x = ThinBoxedSlice::from(vec![0; TAG_LIMIT].into_boxed_slice());
+    assert!(x.spilled_storage().is_some());
+}
+
+#[cfg(target_arch = "x86_64")]
+#[test]
+fn test_from_raw_large() {
+    let mut vec = vec![0; TAG_LIMIT];
+    vec[123] = 456;
+
+    let ptr = Box::into_raw(vec.into_boxed_slice());
+    let x = unsafe { ThinBoxedSlice::from_raw(ptr) };
+    assert_eq!(x[123], 456);
+}
+
+#[cfg(target_arch = "x86_64")]
+#[test]
+fn test_into_raw_large() {
+    let mut vec = vec![0; TAG_LIMIT];
+    vec[123] = 456;
+
+    let x = ThinBoxedSlice::from(vec.into_boxed_slice());
+    let ptr = ThinBoxedSlice::into_raw(x);
+    let y = unsafe { Box::from_raw(ptr) };
+    assert_eq!(y[123], 456);
+}
+
+#[cfg(target_arch = "x86_64")]
+#[test]
+fn test_leak_large() {
+    let mut vec = vec![0; TAG_LIMIT];
+    vec[123] = 456;
+
+    let x = ThinBoxedSlice::from(vec.into_boxed_slice());
+    let static_ref = ThinBoxedSlice::leak(x);
+    static_ref[123] *= 1000;
+    assert_eq!(static_ref[123], 456000);
+}