Installation

std::offload is partly available in nightly builds for users. For now, everyone however still needs to build rustc from source to use all features of it.

Build instructions

First you need to clone and configure the Rust repository:

git clone git@github.com:rust-lang/rust
cd rust
./configure --enable-llvm-link-shared --release-channel=nightly --enable-llvm-assertions --enable-llvm-offload --enable-llvm-enzyme --enable-clang --enable-lld --enable-option-checking --enable-ninja --disable-docs

Afterwards you can build rustc using:

./x build --stage 1 library

Afterwards rustc toolchain link will allow you to use it through cargo:

rustup toolchain link offload build/host/stage1
rustup toolchain install nightly # enables -Z unstable-options

Build instruction for LLVM itself

git clone git@github.com:llvm/llvm-project
cd llvm-project
mkdir build
cd build
cmake -G Ninja ../llvm -DLLVM_TARGETS_TO_BUILD="host,AMDGPU,NVPTX" -DLLVM_ENABLE_ASSERTIONS=ON -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_ENABLE_RUNTIMES="offload,openmp" -DLLVM_ENABLE_PLUGINS=ON -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=.
ninja
ninja install

This gives you a working LLVM build.

Testing

run

./x test --stage 1 tests/codegen-llvm/gpu_offload