# Portable Bitwise Manipulation Intrinsics
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> `0b0000_0010_1001_1010`
This library exposes _safe_ and __portable_ low-level bit manipulation
instruction set architectures. It is `#![no_std]` but requires the
`core::{intrinsics, arch}` components when compiled with nightly rust.
For higher-level bitwise manipulations check the [bitwise][bitwise_link] crate.
This library compiles on `stable` Rust, but provides an `unstable` crate feature that
makes uses of the following nightly features:
* [`cfg_target_feature`][cfg_target_feature] for target-feature dependent behavior,
* `stdsimd`: for `core::arch` intrinsics,
* `core_intrinsics`: for `core::intrinsics`.
The intrinsics are exposed via traits named after their CPU instruction. These
traits are implemented for all integer types _except_ `u128/i128`.
The following ISAs are implemented:
- x86 (`bitintr::x86`):
- [`ABM`][abm_link]: Advanced Bit Manipulation instructions ([`bitintr::x86::abm`](https://gnzlbg.github.io/bitintr/bitintr/x86/abm/index.html)).
- [`TBM`][tbm_link]: Trailing Bit Manipulation instructions ([`bitintr::x86::tbm`](https://gnzlbg.github.io/bitintr/bitintr/x86/tbm/index.html)).
- [`BMI`][bmi1_link]: Bit Manipulation Instruction Set 1.0 ([`bitintr::x86::bmi`](https://gnzlbg.github.io/bitintr/bitintr/x86/bmi/index.html)).
- [`BMI2`][bmi2_link]: Bit Manipulation Instruction Set 2.0 ([`bitintr::x86::bmi2`](https://gnzlbg.github.io/bitintr/bitintr/x86/bmi2/index.html)).
- ARM (`bitintr::arm`):
- [`ARMv5`][armv5_link]: [`bitintr::arm::v5`](https://gnzlbg.github.io/bitintr/bitintr/arm/v5/index.html).
- [`ARMv6`][armv6_link]: [`bitintr::arm::v6`](https://gnzlbg.github.io/bitintr/bitintr/arm/v6/index.html).
- [`ARMv7`][armv7_link]: [`bitintr::arm::v7`](https://gnzlbg.github.io/bitintr/bitintr/arm/v7/index.html).
- [`ARMv8`][armv8_link]: [`bitintr::arm::v8`](https://gnzlbg.github.io/bitintr/bitintr/arm/v8/index.html).
The actual code generated depends on the integer types involved and the features
supported by the target architecture.
## Verified assembly
The `check_asm.py` script verifies the generated assembly of the
intrinsics. It compiles the `asm/arch_feature_*.rs` for the appropriate
architectures and target features and compares the assembly generated by rustc
with that included in the corresponding `asm/arch_feature_*.asm` files.
## License
Licensed under the [MIT license][license].
## Contribution
Yes please! Just note that all contributions shall be licensed as above without
any additional terms or conditions.
[travis-shield]: https://img.shields.io/travis/gnzlbg/bitintr.svg?style=flat-square
[travis]: https://travis-ci.org/gnzlbg/bitintr
[coveralls-shield]: https://img.shields.io/coveralls/gnzlbg/bitintr.svg?style=flat-square
[coveralls]: https://coveralls.io/github/gnzlbg/bitintr
[docs-shield]: https://img.shields.io/badge/docs-online-blue.svg?style=flat-square
[docs]: https://gnzlbg.github.io/bitintr
[license-shield]: https://img.shields.io/github/license/mashape/apistatus.svg?style=flat-square
[license]: https://github.com/gnzlbg/bitintr/blob/master/license.md
[crate-shield]: https://img.shields.io/crates/v/bitintr.svg?style=flat-square
[crate]: https://crates.io/crates/bitintr
[abm_link]: https://en.wikipedia.org/wiki/Bit_Manipulation_Instruction_Sets#ABM_.28Advanced_Bit_Manipulation.29
[tbm_link]: https://en.wikipedia.org/wiki/Bit_Manipulation_Instruction_Sets#TBM_.28Trailing_Bit_Manipulation.29
[bmi1_link]: https://en.wikipedia.org/wiki/Bit_Manipulation_Instruction_Sets#BMI1_.28Bit_Manipulation_Instruction_Set_1.29
[bmi2_link]: https://en.wikipedia.org/wiki/Bit_Manipulation_Instruction_Sets#BMI2_.28Bit_Manipulation_Instruction_Set_2.29
[armv5_link]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0100i/index.html
[armv6_link]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0419c/index.html
[armv7_link]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0403e.b/index.html
[armv8_link]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0487a.k_10775/index.html
[cfg_target_feature]: https://github.com/rust-lang/rust/issues/29717
[bitwise_link]: https://github.com/gnzlbg/bitwise