portable-atomic

Implement workaround for std cpuid bug due to LLVM bug (rust-lang/rust#101346, llvm/llvm-project#57550).

• Our use case is likely not affected, but we implement this just in case.
• We've confirmed that the uses of inline assembly in this crate are not affected by this LLVM bug.

Optimize atomic load/store on no-std pre-v6 ARM when portable_atomic_unsafe_assume_single_core cfg is used. (#36)

Support pre-power8 powerpc64le. powerpc64le's default cpu version is power8, but you can technically compile it for the old cpu using the unsafe -C target-cpu rustc flag.

Use track_caller when debug assertions are enabled on Rust 1.46+.

Make powerpc64 128-bit atomics compatible with Miri and ThreadSanitizer on LLVM 15+.

Document that 128-bit atomics are compatible with Miri and ThreadSanitizer on recent nightly.

Always provide atomic CAS for MSP430 and AVR. (#31)

This previously required unsafe cfg portable_atomic_unsafe_assume_single_core, but since all MSP430 and AVR are single-core, we can safely provide atomic CAS based on disabling interrupts.

Support fence and compiler_fence on MSP430. (On MSP430, the standard library's fences are currently unavailable due to LLVM errors.)

Update safety requirements for unsafe cfg portable_atomic_unsafe_assume_single_core to mention use of privileged instructions to disable interrupts.

Atomic operations based on disabling interrupts on single-core systems are now considered lock-free.

The previous behavior was inconsistent because we consider the pre-v6 ARM Linux's atomic operations provided in a similar way by the Linux kernel to be lock-free.

Respect -Zallow-features.

Fix build error on old Miri.

Documentation improvements.

Provide stable equivalent of #![feature(strict_provenance_atomic_ptr)]. (#23)

• AtomicPtr::fetch_ptr_{add,sub}
• AtomicPtr::fetch_byte_{add,sub}
• AtomicPtr::fetch_{or,and,xor}

These APIs are compatible with strict-provenance on cfg(miri). Otherwise, they are compatible with permissive-provenance.
Once #![feature(strict_provenance_atomic_ptr)] is stabilized, these APIs will be strict-provenance compatible in all cases from the version in which it is stabilized.

Provide stable equivalent of #![feature(atomic_bool_fetch_not)]. (#24)

• AtomicBool::fetch_not

Optimize x86_64 128-bit RMWs. (#22)

Optimize x86_64 outline-atomics.

Optimize inline assemblies on ARM and AArch64.

Revert thumbv6m atomic load/store changes made in 0.3.5. This is because rust-lang/rust#99595 has been reverted, so this is no longer needed.

Optimize x86_64 128-bit atomic load/store on Intel CPU with AVX. (#16)

Support native 128-bit atomic operations for powerpc64 (le or pwr8+, currently nightly-only).

Fix behavior differences between stable and nightly. (#15)

Optimize AArch64 128-bit atomic load/store when the lse2 target feature is enabled at compile-time. (#11)

Relax ordering in Debug impl to reflect std changes. (#12)

Support native 128-bit atomic operations for s390x (currently nightly-only).

Add AtomicF{32,64}::fetch_abs.

Add #[must_use] to constructors.

Use 128-bit atomic operation mappings same as LLVM, on aarch64.

Remove parking_lot optional feature to allow the use of this crate within global allocators.

Remove i128 feature. Atomic{I,U}128 are now always enabled.

Add outline-atomics feature. Currently, this is the same as the 0.1's i128-dynamic, except that fallback feature is not implicitly enabled.

Remove i128-dynamic feature in favor of outline-atomics feature.

Add AtomicF{32,64}::as_bits.