1 # Cranelift codegen backend for rust
3 The goal of this project is to create an alternative codegen backend for the rust compiler based on [Cranelift](https://github.com/bytecodealliance/wasmtime/blob/main/cranelift).
4 This has the potential to improve compilation times in debug mode.
5 If your project doesn't use any of the things listed under "Not yet supported", it should work fine.
6 If not please open an issue.
8 ## Building and testing
11 $ git clone https://github.com/bjorn3/rustc_codegen_cranelift.git
12 $ cd rustc_codegen_cranelift
13 $ ./prepare.sh # download and patch sysroot src and install hyperfine for benchmarking
17 To run the test suite replace the last command with:
23 This will implicitly build cg_clif too. Both `build.sh` and `test.sh` accept a `--debug` argument to
26 Alternatively you can download a pre built version from [GHA]. It is listed in the artifacts section
27 of workflow runs. Unfortunately due to GHA restrictions you need to be logged in to access it.
29 [GHA]: https://github.com/bjorn3/rustc_codegen_cranelift/actions?query=branch%3Amaster+event%3Apush+is%3Asuccess
33 rustc_codegen_cranelift can be used as a near-drop-in replacement for `cargo build` or `cargo run` for existing projects.
35 Assuming `$cg_clif_dir` is the directory you cloned this repo into and you followed the instructions (`prepare.sh` and `build.sh` or `test.sh`).
37 In the directory with your project (where you can do the usual `cargo build`), run:
40 $ $cg_clif_dir/build/cargo.sh build
43 This will build your project with rustc_codegen_cranelift instead of the usual LLVM backend.
45 For additional ways to use rustc_codegen_cranelift like the JIT mode see [usage.md](docs/usage.md).
49 See [env_vars.md](docs/env_vars.md) for all env vars used by rustc_codegen_cranelift.
53 * Inline assembly ([no cranelift support](https://github.com/bytecodealliance/wasmtime/issues/1041))
54 * On Linux there is support for invoking an external assembler for `global_asm!` and `asm!`.
55 `llvm_asm!` will remain unimplemented forever. `asm!` doesn't yet support reg classes. You
56 have to specify specific registers instead.
57 * SIMD ([tracked here](https://github.com/bjorn3/rustc_codegen_cranelift/issues/171), some basic things work)
61 Licensed under either of
63 * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
64 http://www.apache.org/licenses/LICENSE-2.0)
65 * MIT license ([LICENSE-MIT](LICENSE-MIT) or
66 http://opensource.org/licenses/MIT)
72 Unless you explicitly state otherwise, any contribution intentionally submitted
73 for inclusion in the work by you shall be dual licensed as above, without any
74 additional terms or conditions.