/rust/registry/src/index.crates.io-1949cf8c6b5b557f/rav1e-0.8.1/src/util/align.rs

Source
// Copyright (c) 2017-2022, The rav1e contributors. All rights reserved
//
// This source code is subject to the terms of the BSD 2 Clause License and
// the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
// was not distributed with this source code in the LICENSE file, you can
// obtain it at www.aomedia.org/license/software. If the Alliance for Open
// Media Patent License 1.0 was not distributed with this source code in the
// PATENTS file, you can obtain it at www.aomedia.org/license/patent.

use std::mem::MaybeUninit;

#[repr(align(64))]
pub struct Align64;

// A 64 byte aligned piece of data.
// # Examples
// ```
// let mut x: Aligned<[i16; 64 * 64]> = Aligned::new([0; 64 * 64]);
// assert!(x.data.as_ptr() as usize % 16 == 0);
//
// let mut x: Aligned<[i16; 64 * 64]> = Aligned::uninitialized();
// assert!(x.data.as_ptr() as usize % 16 == 0);
// ```
pub struct Aligned<T> {
  _alignment: [Align64; 0],
  pub data: T,
}

#[cfg(any(test, feature = "bench"))]
impl<const N: usize, T> Aligned<[T; N]> {
  #[inline(always)]
  pub fn from_fn<F>(cb: F) -> Self
  where
    F: FnMut(usize) -> T,
  {
    Aligned { _alignment: [], data: std::array::from_fn(cb) }
  }
}

impl<const N: usize, T> Aligned<[MaybeUninit<T>; N]> {
  #[inline(always)]
  pub const fn uninit_array() -> Self {
    Aligned {
      _alignment: [],
      // SAFETY: Uninitialized [MaybeUninit<T>; N] is valid.
      data: unsafe { MaybeUninit::uninit().assume_init() },
    }
  }
}

impl<T> Aligned<T> {
  pub const fn new(data: T) -> Self {
    Aligned { _alignment: [], data }
  }
  #[allow(clippy::uninit_assumed_init)]
  /// # Safety
  ///
  /// The resulting `Aligned<T>` *must* be written to before it is read from.
  pub const unsafe fn uninitialized() -> Self {
    Self::new(MaybeUninit::uninit().assume_init())
  }
}

#[cfg(test)]
mod test {
  use super::*;

  fn is_aligned<T>(ptr: *const T, n: usize) -> bool {
    ((ptr as usize) & ((1 << n) - 1)) == 0
  }

  #[test]
  fn sanity_stack() {
    let a: Aligned<_> = Aligned::new([0u8; 3]);
    assert!(is_aligned(a.data.as_ptr(), 4));
  }
}

Coverage Report

Created: 2025-12-11 07:11

Line	Count	Source
1		// Copyright (c) 2017-2022, The rav1e contributors. All rights reserved
2		//
3		// This source code is subject to the terms of the BSD 2 Clause License and
4		// the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
5		// was not distributed with this source code in the LICENSE file, you can
6		// obtain it at www.aomedia.org/license/software. If the Alliance for Open
7		// Media Patent License 1.0 was not distributed with this source code in the
8		// PATENTS file, you can obtain it at www.aomedia.org/license/patent.
9
10		use std::mem::MaybeUninit;
11
12		#[repr(align(64))]
13		pub struct Align64;
14
15		// A 64 byte aligned piece of data.
16		// # Examples
17		// ```
18		// let mut x: Aligned<[i16; 64 * 64]> = Aligned::new([0; 64 * 64]);
19		// assert!(x.data.as_ptr() as usize % 16 == 0);
20		//
21		// let mut x: Aligned<[i16; 64 * 64]> = Aligned::uninitialized();
22		// assert!(x.data.as_ptr() as usize % 16 == 0);
23		// ```
24		pub struct Aligned<T> {
25		_alignment: [Align64; 0],
26		pub data: T,
27		}
28
29		#[cfg(any(test, feature = "bench"))]
30		impl<const N: usize, T> Aligned<[T; N]> {
31		#[inline(always)]
32		pub fn from_fn<F>(cb: F) -> Self
33		where
34		F: FnMut(usize) -> T,
35		{
36		Aligned { _alignment: [], data: std::array::from_fn(cb) }
37		}
38		}
39
40		impl<const N: usize, T> Aligned<[MaybeUninit<T>; N]> {
41		#[inline(always)]
42	0	pub const fn uninit_array() -> Self {
43	0	Aligned {
44	0	_alignment: [],
45	0	// SAFETY: Uninitialized [MaybeUninit<T>; N] is valid.
46	0	data: unsafe { MaybeUninit::uninit().assume_init() },
47	0	}
48	0	} Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i8>; 1024]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<u16>; 257]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i32>; 4096]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i32>; 64]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i16>; 1024]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i32>; 1024]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i16>; 4096]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<u8>; 257]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i16>; 1024]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i32>; 4096]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i32>; 64]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i16>; 4096]>>::uninit_array Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<i8>; 1024]>>::uninit_array
49		}
50
51		impl<T> Aligned<T> {
52	0	pub const fn new(data: T) -> Self {
53	0	Aligned { _alignment: [], data }
54	0	} Unexecuted instantiation: <rav1e::util::align::Aligned<[u16; 16384]>>::new Unexecuted instantiation: <rav1e::util::align::Aligned<arrayvec::arrayvec::ArrayVec<i32, 1024>>>::new Unexecuted instantiation: <rav1e::util::align::Aligned<[core::mem::maybe_uninit::MaybeUninit<u32>; 1024]>>::new Unexecuted instantiation: <rav1e::util::align::Aligned<[u8; 16384]>>::new Unexecuted instantiation: <rav1e::util::align::Aligned<arrayvec::arrayvec::ArrayVec<i16, 1024>>>::new
55		#[allow(clippy::uninit_assumed_init)]
56		/// # Safety
57		///
58		/// The resulting `Aligned<T>` must be written to before it is read from.
59	0	pub const unsafe fn uninitialized() -> Self {
60	0	Self::new(MaybeUninit::uninit().assume_init())
61	0	} Unexecuted instantiation: <rav1e::util::align::Aligned<[u16; 16384]>>::uninitialized Unexecuted instantiation: <rav1e::util::align::Aligned<[u8; 16384]>>::uninitialized
62		}
63
64		#[cfg(test)]
65		mod test {
66		use super::*;
67
68		fn is_aligned<T>(ptr: *const T, n: usize) -> bool {
69		((ptr as usize) & ((1 << n) - 1)) == 0
70		}
71
72		#[test]
73		fn sanity_stack() {
74		let a: Aligned<_> = Aligned::new([0u8; 3]);
75		assert!(is_aligned(a.data.as_ptr(), 4));
76		}
77		}