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Diffstat (limited to '')
-rw-r--r-- | third_party/rust/atomic/src/ops.rs | 666 |
1 files changed, 666 insertions, 0 deletions
diff --git a/third_party/rust/atomic/src/ops.rs b/third_party/rust/atomic/src/ops.rs new file mode 100644 index 0000000000..3626c9ed9a --- /dev/null +++ b/third_party/rust/atomic/src/ops.rs @@ -0,0 +1,666 @@ +// Copyright 2016 Amanieu d'Antras +// +// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or +// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or +// http://opensource.org/licenses/MIT>, at your option. This file may not be +// copied, modified, or distributed except according to those terms. + +use core::cmp; +use core::mem; +use core::num::Wrapping; +use core::ops; +use core::sync::atomic::Ordering; +use fallback; + +#[cfg(all(feature = "nightly", target_has_atomic = "8"))] +use core::sync::atomic::{ AtomicI8, AtomicU8 }; +#[cfg(all(feature = "nightly", target_has_atomic = "16"))] +use core::sync::atomic::{ AtomicI16, AtomicU16 }; +#[cfg(all(feature = "nightly", target_has_atomic = "32"))] +use core::sync::atomic::{ AtomicI32, AtomicU32 }; +#[cfg(all(feature = "nightly", target_has_atomic = "64"))] +use core::sync::atomic::{ AtomicI64, AtomicU64 }; + +#[cfg(not(feature = "nightly"))] +use core::sync::atomic::AtomicUsize; +#[cfg(not(feature = "nightly"))] +const SIZEOF_USIZE: usize = mem::size_of::<usize>(); +#[cfg(not(feature = "nightly"))] +const ALIGNOF_USIZE: usize = mem::align_of::<usize>(); + +#[cfg(feature = "nightly")] +#[inline] +pub const fn atomic_is_lock_free<T>() -> bool { + let size = mem::size_of::<T>(); + // FIXME: switch to … && … && … once that operator is supported in const functions + (1 == size.count_ones()) & (8 >= size) & (mem::align_of::<T>() >= size) +} + +#[cfg(not(feature = "nightly"))] +#[inline] +pub fn atomic_is_lock_free<T>() -> bool { + let size = mem::size_of::<T>(); + 1 == size.count_ones() && SIZEOF_USIZE >= size && mem::align_of::<T>() >= ALIGNOF_USIZE +} + +#[inline] +pub unsafe fn atomic_load<T>(dst: *mut T, order: Ordering) -> T { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy(&(*(dst as *const AtomicU8)).load(order)) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy(&(*(dst as *const AtomicU16)).load(order)) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy(&(*(dst as *const AtomicU32)).load(order)) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy(&(*(dst as *const AtomicU64)).load(order)) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + mem::transmute_copy(&(*(dst as *const AtomicUsize)).load(order)) + } + _ => fallback::atomic_load(dst), + } +} + +#[inline] +pub unsafe fn atomic_store<T>(dst: *mut T, val: T, order: Ordering) { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + (*(dst as *const AtomicU8)).store(mem::transmute_copy(&val), order) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + (*(dst as *const AtomicU16)).store(mem::transmute_copy(&val), order) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + (*(dst as *const AtomicU32)).store(mem::transmute_copy(&val), order) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + (*(dst as *const AtomicU64)).store(mem::transmute_copy(&val), order) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + (*(dst as *const AtomicUsize)).store(mem::transmute_copy(&val), order) + } + _ => fallback::atomic_store(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_swap<T>(dst: *mut T, val: T, order: Ordering) -> T { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy(&(*(dst as *const AtomicU8)).swap(mem::transmute_copy(&val), order)) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).swap(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).swap(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).swap(mem::transmute_copy(&val), order), + ) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + mem::transmute_copy( + &(*(dst as *const AtomicUsize)).swap(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_swap(dst, val), + } +} + +#[inline] +unsafe fn map_result<T, U>(r: Result<T, T>) -> Result<U, U> { + match r { + Ok(x) => Ok(mem::transmute_copy(&x)), + Err(x) => Err(mem::transmute_copy(&x)), + } +} + +#[inline] +pub unsafe fn atomic_compare_exchange<T>( + dst: *mut T, + current: T, + new: T, + success: Ordering, + failure: Ordering, +) -> Result<T, T> { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + map_result((*(dst as *const AtomicU8)).compare_exchange( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + map_result((*(dst as *const AtomicU16)).compare_exchange( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + map_result((*(dst as *const AtomicU32)).compare_exchange( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + map_result((*(dst as *const AtomicU64)).compare_exchange( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + map_result((*(dst as *const AtomicUsize)).compare_exchange( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + _ => fallback::atomic_compare_exchange(dst, current, new), + } +} + +#[inline] +pub unsafe fn atomic_compare_exchange_weak<T>( + dst: *mut T, + current: T, + new: T, + success: Ordering, + failure: Ordering, +) -> Result<T, T> { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + map_result((*(dst as *const AtomicU8)).compare_exchange_weak( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + map_result((*(dst as *const AtomicU16)).compare_exchange_weak( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + map_result((*(dst as *const AtomicU32)).compare_exchange_weak( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + map_result((*(dst as *const AtomicU64)).compare_exchange_weak( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + map_result((*(dst as *const AtomicUsize)).compare_exchange_weak( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )) + } + _ => fallback::atomic_compare_exchange(dst, current, new), + } +} + +#[inline] +pub unsafe fn atomic_add<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T +where + Wrapping<T>: ops::Add<Output = Wrapping<T>>, +{ + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU8)).fetch_add(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).fetch_add(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).fetch_add(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).fetch_add(mem::transmute_copy(&val), order), + ) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + mem::transmute_copy( + &(*(dst as *const AtomicUsize)).fetch_add(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_add(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_sub<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T +where + Wrapping<T>: ops::Sub<Output = Wrapping<T>>, +{ + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU8)).fetch_sub(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).fetch_sub(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).fetch_sub(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).fetch_sub(mem::transmute_copy(&val), order), + ) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + mem::transmute_copy( + &(*(dst as *const AtomicUsize)).fetch_sub(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_sub(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_and<T: Copy + ops::BitAnd<Output = T>>( + dst: *mut T, + val: T, + order: Ordering, +) -> T { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU8)).fetch_and(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).fetch_and(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).fetch_and(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).fetch_and(mem::transmute_copy(&val), order), + ) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + mem::transmute_copy( + &(*(dst as *const AtomicUsize)).fetch_and(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_and(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_or<T: Copy + ops::BitOr<Output = T>>( + dst: *mut T, + val: T, + order: Ordering, +) -> T { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU8)).fetch_or(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).fetch_or(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).fetch_or(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).fetch_or(mem::transmute_copy(&val), order), + ) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + mem::transmute_copy( + &(*(dst as *const AtomicUsize)).fetch_or(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_or(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_xor<T: Copy + ops::BitXor<Output = T>>( + dst: *mut T, + val: T, + order: Ordering, +) -> T { + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU8)).fetch_xor(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).fetch_xor(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).fetch_xor(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).fetch_xor(mem::transmute_copy(&val), order), + ) + } + #[cfg(not(feature = "nightly"))] + SIZEOF_USIZE if mem::align_of::<T>() >= ALIGNOF_USIZE => + { + mem::transmute_copy( + &(*(dst as *const AtomicUsize)).fetch_xor(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_xor(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_min<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + // Silence warning, fetch_min is not stable yet + #[cfg(not(feature = "nightly"))] + let _ = order; + + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI8)).fetch_min(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI16)).fetch_min(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI32)).fetch_min(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI64)).fetch_min(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_min(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_max<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + // Silence warning, fetch_min is not stable yet + #[cfg(not(feature = "nightly"))] + let _ = order; + + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI8)).fetch_max(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI16)).fetch_max(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI32)).fetch_max(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicI64)).fetch_max(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_max(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_umin<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + // Silence warning, fetch_min is not stable yet + #[cfg(not(feature = "nightly"))] + let _ = order; + + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU8)).fetch_min(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).fetch_min(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).fetch_min(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).fetch_min(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_min(dst, val), + } +} + +#[inline] +pub unsafe fn atomic_umax<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + // Silence warning, fetch_min is not stable yet + #[cfg(not(feature = "nightly"))] + let _ = order; + + match mem::size_of::<T>() { + #[cfg(all(feature = "nightly", target_has_atomic = "8"))] + 1 if mem::align_of::<T>() >= 1 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU8)).fetch_max(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "16"))] + 2 if mem::align_of::<T>() >= 2 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU16)).fetch_max(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "32"))] + 4 if mem::align_of::<T>() >= 4 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU32)).fetch_max(mem::transmute_copy(&val), order), + ) + } + #[cfg(all(feature = "nightly", target_has_atomic = "64"))] + 8 if mem::align_of::<T>() >= 8 => + { + mem::transmute_copy( + &(*(dst as *const AtomicU64)).fetch_max(mem::transmute_copy(&val), order), + ) + } + _ => fallback::atomic_max(dst, val), + } +} |