WIP Cranelift codegen backend for rust

⚠⚠⚠ Threads and certain kinds of FFI don't work yet. ⚠⚠⚠

Building

$ git clone https://github.com/bjorn3/rustc_codegen_cranelift.git
$ cd rustc_codegen_cranelift
$ ./prepare.sh # download and patch sysroot src and install hyperfine for benchmarking
$ ./test.sh --release

Usage

$cg_clif_dir is the directory you cloned this repo into in the following instruction.

Cargo

$ export CG_CLIF_INCR_CACHE=1 # Enable caching of object files in the incremental cache
$ CHANNEL="release" $cg_clif_dir/cargo.sh run

If you compiled cg_clif in debug mode you should use CHANNEL="debug" instead or omit CHANNEL="release" completely.

Rustc

$ export CG_CLIF_INCR_CACHE=1 # Enable caching of object files in the incremental cache
$ rustc -Cpanic=abort -Zcodegen-backend=$cg_clif_dir/target/release/librustc_codegen_cranelift.so --sysroot $cg_clif_dir/build_sysroot/sysroot my_crate.rs

Not yet supported

• Good non-rust abi support (several problems)
• Checked binops (some missing instructions in cranelift)
• Inline assembly (no cranelift support, not coming soon)
• SIMD (tracked here, some basic things work)