remove element_unordered_atomic intrinsics by RalfJung · Pull Request #789 · rust-lang/compiler-builtins (original) (raw)

It is not clear how these "unordered" operations are supposed to fit the memory model. The intrinsics used here are labeled with "DO NOT USE" in the docs. The plan in rust-lang/rfcs#3301 and for C++, as I understand it, is to have "bytewise atomic memcpy" with the usual orderings: SeqCst, Release, Acquire, Relaxed. These "unordered" intrinsics seem to be a dead end.

These intrinsics are also unused as far as I can tell; rust-lang/rust#59155 which planned to use them never landed.

Part of #788.