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bjorn3
rustc_codegen_cranelift
Rust2019–2023
bjorn3 / rustc_codegen_cranelift

rustc_codegen_cranelift

You are probably looking for the upstream version of rustc_codegen_cranelift

22Distinct people
25Mentions
0Explicit recommenders
19GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

You are probably looking for the upstream version of rustc_codegen_cranelift

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

Mentioned in the same Hacker News threads. That is not proof they are substitutes.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 1:49:46 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year25 dated mentions

Observed mentions: 2019-04-11 23:02:32 UTC to 2023-08-17 22:36:36 UTC.

02462019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments20192020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 7 mentions; 0 submissions, 7 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments20212022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 4 mentions; 1 submissions, 3 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 6 mentions; 0 submissions, 6 comments2023

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC404
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC707
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC404
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC413
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC606

From the project README

An excerpt from the repository, fetched Nov 13, 2026.

Read the project’s introduction
Cranelift codegen backend for rust The goal of this project is to create an alternative codegen backend for the rust compiler based on Cranelift. This has the potential to improve compilation times in debug mode. If your project doesn't use any of the things listed under "Not yet supported", it should work fine. If not please open an issue. Download using Rustup The Cranelift codegen backend is distributed in nightly builds on Linux and x86_64 macOS. If you want to install it using Rustup, you can do that by running: $ rustup component add rustc-codegen-cranelift-preview --toolchain nightly Once it is installed, you can enable it with one of the following approaches: CARGO_PROFILE_DEV_CODEGEN_BACKEND=cranelift cargo +nightly build -Zcodegen-backend RUSTFLAGS="-Zcodegen-backend=cranelift" cargo +nightly build Add the following to .cargo/config.toml: [unstable] codegen-backend = true [profile.dev] codegen-backend = "cranelift" Add the following to Cargo.toml: # This line needs to come before anything else in Cargo.toml cargo-features = ["codegen-backend"] [profile.dev] codegen-backend = "cranelift" Precompiled builds You can also download a pre-built version from the releases page. Extract the dist directory in the archive anywhere you want. If you want to use cargo clif build instead of having to specify the full path to the cargo-clif executable, you can add the bin subdirectory of the extracted dist directory to your PATH. (tutorial for Windows, and for Linux/MacOS). Building and testing If you want to build the backend manually, you can download it from GitHub and build it yourself: $ git clone https://github.com/rust-lang/rustc_codegen_cranelift $ cd rustc_codegen_cranelift $ ./y.sh prepare $ ./y.sh build To run the test suite replace the last command with: $ ./test.sh For more docs on how to build and test see build_system/usage.txt or the help message of ./y.sh. Platform support OS \ architecture x86_64 AArch64 Riscv64 s390x (System-Z) Linux ✅ ✅ ✅1 ✅1 FreeBSD ✅1 ❓ ❓ ❓ AIX ❌2 N/A N/A ❌2 Other unixes ❓ ❓ ❓ ❓ macOS ✅ ✅1 N/A N/A Windows ✅1 ❌ N/A N/A ✅: Fully supported and tested ❓: Maybe supported, not tested ❌: Not supported at all Not all targets are available as rustup component for nightly. See notes in the platform support matrix. Usage rustc_codegen_cranelift can be used as a near-drop-in replacement for cargo build or cargo run for existing projects. Assuming $cg_clif_dir is the directory you cloned this repo into and you followed the instructions (y.sh prepare and y.sh build or test.sh). In the directory with your project (where you can do the usual cargo build), run: $ $cg_clif_dir/dist/cargo-clif build This will build your project with rustc_codegen_cranelift instead of the usual LLVM backend. For additional ways to use rustc_codegen_cranelift like the JIT mode see usage.md. Building and testing with changes in rustc code See rustc_testing.md. Not yet supported SIMD (tracked here, std::simd fully works, std::arch is partially supported) Unwinding on panics (no cranelift support, -Cpanic=abort is enabled by default) License Licensed under either of Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0) MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT) at your option. Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions. Footnotes Not available as rustup component for nightly. You can build it yourself. ↩ ↩2 ↩3 ↩4 ↩5 XCOFF object file format is not supported. ↩ ↩2
Read the full README on GitHub

What Hacker News says

25 sources
> When this happens, it seems like it'll be possible to get the LLVM bits out of the bootstrap process and lead to a fully self-hosted Rust. What do you mean by "when this happens"? GP's point is that this has already happened: the Cranelift backend is feature-complete from the perspective of the language [0], except for inline assembly and unwinding on panic. It was merged into the upstream compiler in 2020 [1], and a Cranelift-based Rust compiler is perfectly capable of bootstrapping another Rust compiler (with some config changes) [2]. [0] https://github.com/bjorn3/rustc_codegen_cranelift [1] https://github.com/rust-lang/rust/pull/77975 [2] https://github.com/bjorn3/rustc_codegen_cranelift/actions/ru...
In A Guide to Undefined Behavior in C and C++ (2010)
Cranelift is not used for debug builds by default. I think that's probably a goal (although I'm not actually 100% sure about that just because I'm not dialed into what the compiler team is doing). Even the OP mentions this: > We were able to benchmark bjorn3's cranelift codegen backend on full crates as well as on the build dependencies specifically (since they're also built for cargo check builds, and are always built without optimizations): there were no issues, and it performed impressively. It's well on its way to becoming a viable alternative to the LLVM backend for debug builds. And the Cranelift codegen backend itself is also clear about it not being ready yet: https://github.com/bjorn3/rustc_codegen_cranelift (To be clear, I am super excited about using Cranelift for debug builds. I just want to clarify that it isn't actually used
Read the rest
by default yet.)
In Improving Rust compile times to enable adoption of memory safety
Strictly speaking rustc has a dependency on LLVM, which is in C++, but you could use the rustc_codegen_cranelift backend [1] and get pretty much everything to be pure Rust. Unless you count the libc dependency, in which case, um, I guess you could use relibc [2]? And if you think relying on OS syscalls implemented in not-Rust is cheating, then you could just use Redox directly ;) [1] https://github.com/bjorn3/rustc_codegen_cranelift [2] https://github.com/redox-os/relibc
In Are we game yet? – A guide to the Rust game development ecosystem
Similarly you can compile Rust in "edition = 2015" or "edition = 2018" and soon "edition = 2021" to guard against changes in the language, e.g. adding keywords. There are already alternative compilers, though most of them are WIP, e.g. mrustc[1], rust front-end for gcc[2][3], or using cranelift[4] for the back-end. [1] https://github.com/thepowersgang/mrustc [2] https://github.com/sapir/gcc-rust/tree/rust [3] https://github.com/Rust-GCC/gccrs [4] https://github.com/bjorn3/rustc_codegen_cranelift
In AWS hires Rust compiler team co-lead Felix Klock

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