dc103c4cd9
RISC-V: Implement (Zkne or Zknd) intrinsics correctly On rust-lang/stdarch#1765, it has been pointed out that two RISC-V (64-bit only) intrinsics to perform AES key scheduling have wrong target feature. `aes64ks1i` and `aes64ks2` instructions require *either* Zkne (scalar cryptography: AES encryption) or Zknd (scalar cryptography: AES decryption) extension (or both) but corresponding Rust intrinsics (in `core::arch::riscv64`) required *both* Zkne and Zknd extensions. An excerpt from the original intrinsics: ```rust #[target_feature(enable = "zkne", enable = "zknd")] ``` To fix that, we need to: 1. Represent a condition where *either* Zkne or Zknd is available and 2. Workaround an issue: `llvm.riscv.aes64ks1i` / `llvm.riscv.aes64ks2` LLVM intrinsics require either Zkne or Zknd extension. This PR attempts to resolve them by: 1. Adding a perma-unstable RISC-V target feature: `zkne_or_zknd` (implied from both `zkne` and `zknd`) and 2. Using inline assembly to construct machine code directly (because `zkne_or_zknd` alone cannot imply neither Zkne nor Zknd, we cannot use LLVM intrinsics). The author confirmed that we can construct an AES key scheduling function with decent performance using fixed `aes64ks1i` and `aes64ks2` intrinsics (with optimization enabled). |
||
|---|---|---|
| .. | ||
| .github/workflows | ||
| ci | ||
| crates | ||
| examples | ||
| intrinsics_data | ||
| .git-blame-ignore-revs | ||
| .gitignore | ||
| .gitmodules | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CONTRIBUTING.md | ||
| josh-sync.toml | ||
| LICENSE-APACHE | ||
| LICENSE-MIT | ||
| README.md | ||
| rust-version | ||
| rustfmt.toml | ||
| triagebot.toml | ||
| vendor.yml | ||
stdarch - Rust's standard library SIMD components
This repository contains the core_arch crate, which implements core::arch - Rust's core library architecture-specific intrinsics.
The std::simd component now lives in the
packed_simd_2 crate.
Synchronizing josh subtree with rustc
This repository is linked to rust-lang/rust as a josh subtree. You can use the rustc-josh-sync tool to perform synchronization.
You can find a guide on how to perform the synchronization here.