Amanieu d'Antras 7f5fd0955a Disable NEON intrinsics on big-endian ARM
These are currently broken because the order of elements inside
vectors is reversed on big-endian systems: the ARM ABI requires that
element 0 is located at the highest address of the vector type. However
LLVM intrinsics expect element 0 to be located at the lowest address.

See https://llvm.org/docs/BigEndianNEON.html and `arm_neon.h` in
Clang for more details.

Although this is a breaking change, this is acceptable for 2 reasons:
- big endian ARM targets are only tier 3.
- it is preferable to stop existing code from compiling than to let it
run and produce incorrect results.
2023-10-21 16:29:18 +02:00
..
2022-02-08 15:09:09 +00:00
2021-11-19 01:24:36 +00:00

core::arch - Rust's core library architecture-specific intrinsics

The core::arch module implements architecture-dependent intrinsics (e.g. SIMD).

Usage

core::arch is available as part of libcore and it is re-exported by libstd. Prefer using it via core::arch or std::arch than via this crate. Unstable features are often available in nightly Rust via the feature(stdsimd).

Using core::arch via this crate requires nightly Rust, and it can (and does) break often. The only cases in which you should consider using it via this crate are:

  • if you need to re-compile core::arch yourself, e.g., with particular target-features enabled that are not enabled for libcore/libstd. Note: if you need to re-compile it for a non-standard target, please prefer using xargo and re-compiling libcore/libstd as appropriate instead of using this crate.

  • using some features that might not be available even behind unstable Rust features. We try to keep these to a minimum. If you need to use some of these features, please open an issue so that we can expose them in nightly Rust and you can use them from there.

Documentation

License

core_arch is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.

See LICENSE-APACHE, and LICENSE-MIT for details.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in core_arch by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.