use crate::{DeviceSize, NonZeroDeviceSize};
use std::{
cmp::Ordering,
error::Error,
fmt::{Debug, Display, Formatter, Result as FmtResult},
hash::{Hash, Hasher},
mem::{self, align_of, size_of},
};
#[derive(Clone, Copy, PartialEq, Eq)]
#[repr(transparent)]
pub struct DeviceAlignment(AlignmentEnum);
const _: () = assert!(size_of::<DeviceAlignment>() == size_of::<DeviceSize>());
const _: () = assert!(align_of::<DeviceAlignment>() == align_of::<DeviceSize>());
impl DeviceAlignment {
pub const MIN: Self = Self(AlignmentEnum::_Align1Shl0);
pub const MAX: Self = Self(AlignmentEnum::_Align1Shl63);
#[inline]
pub const fn of<T>() -> Self {
#[cfg(any(
target_pointer_width = "64",
target_pointer_width = "32",
target_pointer_width = "16",
))]
{
const _: () = assert!(size_of::<DeviceSize>() >= size_of::<usize>());
unsafe { DeviceAlignment::new_unchecked(align_of::<T>() as DeviceSize) }
}
}
#[inline]
pub const fn new(alignment: DeviceSize) -> Option<Self> {
if alignment.is_power_of_two() {
Some(unsafe { DeviceAlignment::new_unchecked(alignment) })
} else {
None
}
}
#[inline]
pub const unsafe fn new_unchecked(alignment: DeviceSize) -> Self {
debug_assert!(alignment.is_power_of_two());
unsafe { mem::transmute::<DeviceSize, DeviceAlignment>(alignment) }
}
#[inline]
pub const fn as_devicesize(self) -> DeviceSize {
self.0 as DeviceSize
}
#[inline]
pub const fn as_nonzero(self) -> NonZeroDeviceSize {
unsafe { NonZeroDeviceSize::new_unchecked(self.as_devicesize()) }
}
#[inline]
pub const fn log2(self) -> u32 {
self.as_nonzero().trailing_zeros()
}
#[inline(always)]
pub(crate) const fn max(self, other: Self) -> Self {
if self.as_devicesize() >= other.as_devicesize() {
self
} else {
other
}
}
}
impl Debug for DeviceAlignment {
fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
write!(f, "{:?} (1 << {:?})", self.as_nonzero(), self.log2())
}
}
impl Default for DeviceAlignment {
#[inline]
fn default() -> Self {
DeviceAlignment::MIN
}
}
impl TryFrom<NonZeroDeviceSize> for DeviceAlignment {
type Error = TryFromIntError;
#[inline]
fn try_from(alignment: NonZeroDeviceSize) -> Result<Self, Self::Error> {
if alignment.is_power_of_two() {
Ok(unsafe { DeviceAlignment::new_unchecked(alignment.get()) })
} else {
Err(TryFromIntError)
}
}
}
impl TryFrom<DeviceSize> for DeviceAlignment {
type Error = TryFromIntError;
#[inline]
fn try_from(alignment: DeviceSize) -> Result<Self, Self::Error> {
DeviceAlignment::new(alignment).ok_or(TryFromIntError)
}
}
impl From<DeviceAlignment> for NonZeroDeviceSize {
#[inline]
fn from(alignment: DeviceAlignment) -> Self {
alignment.as_nonzero()
}
}
impl From<DeviceAlignment> for DeviceSize {
#[inline]
fn from(alignment: DeviceAlignment) -> Self {
alignment.as_devicesize()
}
}
#[allow(clippy::derived_hash_with_manual_eq)]
impl Hash for DeviceAlignment {
#[inline]
fn hash<H: Hasher>(&self, state: &mut H) {
self.as_nonzero().hash(state);
}
}
impl PartialOrd for DeviceAlignment {
#[inline]
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for DeviceAlignment {
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
self.as_nonzero().cmp(&other.as_nonzero())
}
}
#[derive(Clone, Copy, PartialEq, Eq)]
#[repr(u64)]
enum AlignmentEnum {
_Align1Shl0 = 1 << 0,
_Align1Shl1 = 1 << 1,
_Align1Shl2 = 1 << 2,
_Align1Shl3 = 1 << 3,
_Align1Shl4 = 1 << 4,
_Align1Shl5 = 1 << 5,
_Align1Shl6 = 1 << 6,
_Align1Shl7 = 1 << 7,
_Align1Shl8 = 1 << 8,
_Align1Shl9 = 1 << 9,
_Align1Shl10 = 1 << 10,
_Align1Shl11 = 1 << 11,
_Align1Shl12 = 1 << 12,
_Align1Shl13 = 1 << 13,
_Align1Shl14 = 1 << 14,
_Align1Shl15 = 1 << 15,
_Align1Shl16 = 1 << 16,
_Align1Shl17 = 1 << 17,
_Align1Shl18 = 1 << 18,
_Align1Shl19 = 1 << 19,
_Align1Shl20 = 1 << 20,
_Align1Shl21 = 1 << 21,
_Align1Shl22 = 1 << 22,
_Align1Shl23 = 1 << 23,
_Align1Shl24 = 1 << 24,
_Align1Shl25 = 1 << 25,
_Align1Shl26 = 1 << 26,
_Align1Shl27 = 1 << 27,
_Align1Shl28 = 1 << 28,
_Align1Shl29 = 1 << 29,
_Align1Shl30 = 1 << 30,
_Align1Shl31 = 1 << 31,
_Align1Shl32 = 1 << 32,
_Align1Shl33 = 1 << 33,
_Align1Shl34 = 1 << 34,
_Align1Shl35 = 1 << 35,
_Align1Shl36 = 1 << 36,
_Align1Shl37 = 1 << 37,
_Align1Shl38 = 1 << 38,
_Align1Shl39 = 1 << 39,
_Align1Shl40 = 1 << 40,
_Align1Shl41 = 1 << 41,
_Align1Shl42 = 1 << 42,
_Align1Shl43 = 1 << 43,
_Align1Shl44 = 1 << 44,
_Align1Shl45 = 1 << 45,
_Align1Shl46 = 1 << 46,
_Align1Shl47 = 1 << 47,
_Align1Shl48 = 1 << 48,
_Align1Shl49 = 1 << 49,
_Align1Shl50 = 1 << 50,
_Align1Shl51 = 1 << 51,
_Align1Shl52 = 1 << 52,
_Align1Shl53 = 1 << 53,
_Align1Shl54 = 1 << 54,
_Align1Shl55 = 1 << 55,
_Align1Shl56 = 1 << 56,
_Align1Shl57 = 1 << 57,
_Align1Shl58 = 1 << 58,
_Align1Shl59 = 1 << 59,
_Align1Shl60 = 1 << 60,
_Align1Shl61 = 1 << 61,
_Align1Shl62 = 1 << 62,
_Align1Shl63 = 1 << 63,
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct TryFromIntError;
impl Error for TryFromIntError {}
impl Display for TryFromIntError {
fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
f.write_str("attempted to convert a non-power-of-two integer to a `DeviceAlignment`")
}
}