Portable Bitwise Manipulation Intrinsics

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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 crate.

This library compiles on stable Rust, but provides an unstable crate feature that makes uses of the following nightly features:

• 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: Advanced Bit Manipulation instructions (bitintr::x86::abm).
  • TBM: Trailing Bit Manipulation instructions (bitintr::x86::tbm).
  • BMI: Bit Manipulation Instruction Set 1.0 (bitintr::x86::bmi).
  • BMI2: Bit Manipulation Instruction Set 2.0 (bitintr::x86::bmi2).

• ARM (bitintr::arm):

  • ARMv5: bitintr::arm::v5.
  • ARMv6: bitintr::arm::v6.
  • ARMv7: bitintr::arm::v7.
  • ARMv8: bitintr::arm::v8.

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.

Contribution

Yes please! Just note that all contributions shall be licensed as above without any additional terms or conditions.