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The goal of this project is to create an alternative codegen backend for the rust compiler based onCranelift.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.

The Cranelift codegen backend is distributed in nightly builds on Linux, macOS and x86_64 Windows. If you want toinstall 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
• Add the following to.cargo/config.toml:

  [unstable]codegen-backend =true[profile.dev]codegen-backend ="cranelift"

• Add the following toCargo.toml:

  # This line needs to come before anything else in Cargo.tomlcargo-features = ["codegen-backend"][profile.dev]codegen-backend ="cranelift"

You can also download a pre-built version from thereleases page.Extract thedist directory in the archive anywhere you want.If you want to usecargo clif build instead of having to specify the full path to thecargo-clif executable, you can add thebin subdirectory of the extracteddist directory to yourPATH.(tutorialfor Windows, andfor Linux/MacOS).

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_craneliftcd rustc_codegen_cranelift./y.sh build

To run the test suite replace the last command with:

./y.sh prepare# only needs to be run the first time./test.sh

For more docs on how to build and test seebuild_system/usage.txt or the help message of./y.sh.

✅: 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.

rustc_codegen_cranelift can be used as a near-drop-in replacement forcargo build orcargo run for existing projects.

Assuming$cg_clif_dir is the directory you cloned this repo into and you followed the instructions (y.sh prepare andy.sh build ortest.sh).

In the directory with your project (where you can do the usualcargo 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 seeusage.md.

Seerustc_testing.md.

• SIMD (tracked here,std::simd fully works,std::arch is partially supported)
• Unwinding on panics (experimental and not supported on Windows and macOS,-Cpanic=abort is enabled by default)

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE orhttp://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT orhttp://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submittedfor inclusion in the work by you shall be dual licensed as above, without anyadditional terms or conditions.