Building the Library

This page outlines the process of building the dtFFT library using CMake, including compiler requirements, configuration options, and integration instructions for downstream projects. The library supports both host and GPU environments, leveraging modern Fortran and optional dependencies like CUDA, FFTW3, MKL, cuFFT, and VkFFT.

Prerequisites

Since dtFFT is primarily written in Fortran, a modern Fortran compiler (2008 standard or later) is required. The library has been successfully tested with:

  • GNU Fortran (gfortran): Version 12 and above

  • Intel Fortran (ifort / ifx): Version 18 and above

  • NVHPC Fortran (nvfortran): Version 24.5 and above

Currently, dtFFT can only be built using CMake (version 3.20 or higher recommended). Ensure CMake is installed and available in your PATH before proceeding.

Requirements:

  • CMake: Version 3.20 or higher

  • Modern Fortran compiler: 2008 standard or later

  • MPI: Message Passing Interface (MPI) implementation

  • Caliper (optional): For performance profiling and analysis

For CUDA support:

  • CUDA-aware MPI: Required for GPU acceleration

  • NCCL (optional): NVIDIA Collective Communications Library (automatically linked if nvfortran is used)

  • nvfortran (optional): NVHPC Fortran compiler (enables additional features like NCCL and cuFFTMp)

  • NVTX3 (optional): NVIDIA Tools Extension for profiling and debugging

Configuration Options

The build process is controlled via CMake options, listed below. These options enable or disable features such as GPU support, FFT library integration, and additional utilities. Set them using -D<OPTION>=<VALUE> during CMake configuration.

CMake Configuration Options

Option

Possible Values

Default

Description

DTFFT_WITH_CUDA

ON / OFF

OFF

Enables CUDA support. Requires nvcc in the PATH for the target CUDA version.

DTFFT_WITH_FFTW

ON / OFF

OFF

Enables FFTW3 support. Requires the FFTWDIR environment variable to point to a directory with single- and double-precision FFTW3 libraries.

DTFFT_WITH_MKL

ON / OFF

OFF

Enables MKL DFTI support. Requires the MKLROOT environment variable to be set to the MKL installation path.

DTFFT_WITH_CUFFT

ON / OFF

OFF

Enables cuFFT support. Automatically sets DTFFT_WITH_CUDA to ON.

DTFFT_WITH_VKFFT

ON / OFF

OFF

Enables VkFFT support. Requires the VKFFT_DIR variable to point to vkFFT.h and automatically sets DTFFT_WITH_CUDA to ON.

DTFFT_BUILD_TESTS

ON / OFF

OFF

Builds the library’s test suite.

DTFFT_ENABLE_COVERAGE

ON / OFF

OFF

Enables code coverage analysis (gfortran only).

DTFFT_BUILD_SHARED

ON / OFF

ON

Builds a shared library instead of a static one.

DTFFT_USE_MPI

ON / OFF

ON

Uses the Fortran mpi module instead of mpi_f08 for MPI integration. This make possible to pass integer to comm parameter when creating plan instead of type(MPI_Comm), but can produce integer overflow when using CUDA build and big array sizes.

DTFFT_BUILD_C_CXX_API

ON / OFF

ON

Builds the C and C++ APIs alongside the Fortran API.

DTFFT_ENABLE_PERSISTENT_COMM

ON / OFF

OFF

Enables persistent MPI communications for multiple plan executions. Communications are initialized on the first call to execute() or transpose(), with pointers stored internally by MPI. Users must ensure these pointers remain valid and are not freed prematurely.

DTFFT_WITH_PROFILER

ON / OFF

OFF

Enables profiling. Uses NVTX3 with CUDA support or Caliper otherwise (requires caliper_DIR if Caliper is used).

DTFFT_WITH_NCCL

ON / OFF

OFF

Requires the NCCL_ROOT environment variable to point to the custom NCCL directory.

DTFFT_WITHOUT_NCCL

ON / OFF

OFF

Disables use of NCCL shipped with HPC-SDK. NCCL Backends will be unavailable

DTFFT_WITHOUT_NVSHMEM

ON / OFF

OFF

Disables use of NVSHMEM-based backends shipped with HPC-SDK.

DTFFT_WITH_DEVICE_CHECKS

ON / OFF

ON

Enable error checking for all GPU libraries calls

Building the Library

  1. Configure the Build: Run CMake to generate build files, specifying the installation prefix and desired options. For example:

cmake -S . -B build -DCMAKE_INSTALL_PREFIX=/path/to/install -DDTFFT_WITH_CUDA=ON -DDTFFT_WITH_CUFFT=ON

Replace /path/to/install with your target installation directory.

Note

CUDA support in dtFFT does not replace the host version but extends it. For more details, refer to the guide here and the environment variable DTFFT_PLATFORM.

  1. Build the Library: Compile the library using:

cmake --build build --target install

This compiles and installs dtFFT to the specified prefix.

Integration with CMake Projects

Once installed, dtFFT can be integrated into other CMake projects using find_package. Example configuration:

find_package(dtfft REQUIRED)
add_executable(my_prog my_prog.c)
target_link_libraries(my_prog PRIVATE dtfft)

The dtfft target automatically sets include directories and links required libraries. Specify the installation path when configuring your project:

cmake -S . -B build -Ddtfft_DIR=/path/to/install/lib[64]/cmake/dtfft ..

The installation also provides the following CMake variables for conditional compilation:

  • DTFFT_WITH_CUDA: Indicates CUDA support

  • DTFFT_WITH_C_CXX_API: Indicates C/C++ API availability

  • DTFFT_WITH_MPI_MODULE: Indicates use of the mpi module