Portable Computing Language (PoCL)

PoCL is being developed towards an efficient implementation of the OpenCL standard which can be easily adapted for new targets.

Official web page

Full documentation

Building

This section contains instructions for building PoCL in its default configuration and a subset of driver backends. You can find the full build instructions including a list of available options in the user guide.

Requirements

In order to build PoCL, you need the following support libraries and tools:

• Latest released version of LLVM & Clang
• development files for LLVM & Clang + their transitive dependencies (e.g. libclang-dev, libclang-cpp-dev, libllvm-dev, zlib1g-dev, libtinfo-dev...)
• CMake 3.9 or newer
• GNU make or ninja
• pkg-config
• pthread (should be installed by default)
• hwloc v1.0 or newer (e.g. libhwloc-dev) - optional
• python3 (for support of LLVM bitcode with SPIR target; optional but enabled by default)
• llvm-spirv (version-compatible with LLVM) and spirv-tools (optional; required for SPIR-V support in CPU / CUDA; Vulkan driver supports SPIR-V through clspv)

On Ubuntu or Debian based distros you can install the relevant packages with

export LLVM_VERSION=<major LLVM version>
apt install -y python3-dev libpython3-dev build-essential ocl-icd-libopencl1 \
    cmake git pkg-config libclang-${LLVM_VERSION}-dev clang \
    llvm-${LLVM_VERSION} make ninja-build ocl-icd-libopencl1 ocl-icd-dev \
    ocl-icd-opencl-dev libhwloc-dev zlib1g zlib1g-dev clinfo dialog apt-utils \
    libxml2-dev libclang-cpp${LLVM_VERSION}-dev libclang-cpp${LLVM_VERSION} \
    llvm-${LLVM_VERSION}-dev

If your distro does not package the version of LLVM you wish to build against you might want to set up the upstream LLVM package repository.

Configure & Build

Building PoCL follows the usual CMake workflow, i.e.:

cd <directory-with-pocl-sources>
mkdir build
cd build
cmake ..
make
# and optionally
make install

Supported LLVM Versions

PoCL aims to support the latest LLVM version at the time of PoCL release, plus the previous LLVM version. All older LLVM versions are supported on a "best effort" basis; there might not be build bots continuously testing the code base nor anyone fixing their possible breakage.

OpenCL 3.0 support

If you want PoCL built with ICD and OpenCL 3.0 support at platform level, you will need sufficiently new ocl-icd (2.3.x). For Ubuntu, it can be installed' from this PPA: https://launchpad.net/~ocl-icd/+archive/ubuntu/ppa Additionally, if you want the CPU device to report as 3.0 OpenCL you will need LLVM 14 or newer.

GPU support on different architectures

PoCL can be used to provide OpenCL driver on several architectures where the hardware manufacturer does not ship them like Nvidia Tegra (ARM) or IBM Power servers. On PPC64le servers, there are specific instructions to handle the build of PoCL in README.PPC64le.

Windows

Windows support has been unmaintained for a long time and building on Windows may or may not work. There are old instructions for building with Visual Studio in README.Windows but with the builtin CMake support of more recent Visual Studio versions (2019+) it might be enough to install the dependencies (e.g. with winget) and simply open the main CMakeLists.txt file in Visual Studio and let it work its magic.

Contributions for improving compatibility with Windows and more detailed and up to date build steps are welcome!

Notes

Building on ARM platforms is possible but lacks a maintainer and there are some gotchas.

If you are a distro maintainer, check README.packaging for recommendations on build settings for packaged builds.

License

PoCL is distributed under the terms of the MIT license. Contributions are expected to be made with the same terms.