Installation

Installing dependencies

alpaka requires Boost and a modern C++ compiler (g++, clang++, Visual C++, …). In order to install Boost:

On Linux:

# RPM
sudo dnf install boost-devel
# DEB
sudo apt install libboost-all-dev

On macOS:

# Using Homebrew, https://brew.sh
brew install boost
# Using MacPorts, https://macports.org
sudo port install boost

On Windows:

# Using vcpkg, https://github.com/microsoft/vcpkg
vcpkg install boost

CMake is the preferred system for configuration the build tree, building and installing. In order to install CMake:

On Linux:

# RPM
sudo dnf install cmake
# DEB
sudo apt install cmake

On macOS or Windows:

Download the installer from https://cmake.org/download/

Dependencies to use specific backends: Depending on your target platform you may need additional packages to compile and run alpaka.

• NVIDIA GPUs: CUDA Toolkit (https://developer.nvidia.com/cuda-toolkit)

• AMD GPUs: ROCm / HIP (https://rocmdocs.amd.com/en/latest/index.html)

• Intel GPUs: OneAPI Toolkit (https://www.intel.com/content/www/us/en/developer/tools/oneapi/base-toolkit.html#gs.9x3lnh)

Tests and Examples

The examples and tests can be compiled without installing alpaka. They will use alpaka headers from the source directory.

Build and run examples:

# ..
cmake -Dalpaka_BUILD_EXAMPLES=ON ..
cmake --build . -t vectorAdd
./example/vectorAdd/vectorAdd # execution

Build and run tests:

# ..
cmake -DBUILD_TESTING=ON ..
cmake --build .
ctest

Enable accelerators:

Alpaka uses different accelerators to execute kernels on different processors. To use a specific accelerator in alpaka, two steps are required.

1. Enable the accelerator during the CMake configuration time of the project.

2. Select a specific accelerator in the source code.

By default, no accelerator is enabled because some combinations of compilers and accelerators do not work, see the table of supported compilers. To enable an accelerator, you must set a CMake flag via cmake .. -Dalpaka_ACC_<acc>_ENABLE=ON when you create a new build. The following example shows how to enable the CUDA accelerator and build an alpaka project:

cmake -Dalpaka_ACC_GPU_CUDA_ENABLE=ON ...

In the overview of cmake arguments you will find all CMake flags for activating the different accelerators. How to select an accelerator in the source code is described on the example page.

Warning

If an accelerator is selected in the source code that is not activated during CMake configuration time, a compiler error occurs.

Hint

When the test or examples are activated, the alpaka build system automatically activates the serial backend, as it is needed for many tests. Therefore, the tests are run with the serial backend by default. If you want to test another backend, you have to activate it at CMake configuration time, for example the HIP backend: cmake .. -DBUILD_TESTING=ON -Dalpaka_ACC_GPU_HIP_ENABLE=ON. Some alpaka tests use a selector algorithm to choose a specific accelerator for the test cases. The selector works with accelerator priorities. Therefore, it is recommended to enable only one accelerator for a build to make sure that the right one is used.

Installing alpaka

If user is going to create her/his own project/example outside the source tree alpaka should be installed. Since alpaka is a header only library compilation is not needed before installation.

# Clone alpaka from github.com
git clone --branch 1.1.0 https://github.com/alpaka-group/alpaka.git
cd alpaka
mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX=/install/ ..
cmake --install .