hipfort

Hipfort

Usage

Test hipfort by compiling and running a simple Fortran code that uses a HIP kernel to calculate saxpy on the GPU.

The following modules are required:

module load LUMI/23.09
module load partition/G 
module load rocm/5.4.6

Because the default HIPFORT installation only supports gfortran, we use a custom installation prepared in the summer school project. This package provide Fortran modules compatible with the Cray Fortran compiler as well as direct use of hipfort with the Fortran Cray Compiler wrapper (ftn).

The package was installed via:

# In some temporary folder
wget https://github.com/ROCm/hipfort/archive/refs/tags/rocm-6.1.0.tar.gz # one can try various realeases
tar -xvzf rocm-6.1.0.tar.gz;
cd hipfort-rocm-6.1.0;
mkdir build;
cd build;
cmake -DHIPFORT_INSTALL_DIR=<path-to>/HIPFORT -DHIPFORT_COMPILER_FLAGS="-ffree -eZ" -DHIPFORT_COMPILER=<path-to>/ftn -DHIPFORT_AR=${CRAY_BINUTILS_BIN_X86_64}/ar -DHIPFORT_RANLIB=${CRAY_BINUTILS_BIN_X86_64}/ranlib  ..
make -j 64 
make install

We will use the Cray 'ftn' compiler wrapper as you would do to compile any fortran code plus some additional flags:

export HIPFORT_HOME=/projappl/project_465001194/apps/HIPFORT
ftn -I$HIPFORT_HOME/include/hipfort/amdgcn "-DHIPFORT_ARCH=\"amd\"" -L$HIPFORT_HOME/lib -lhipfort-amdgcn $LIB_FLAGS -c <fortran_code>.f90 
CC -xhip -c <hip_kernels>.cpp
ftn  -I$HIPFORT_HOME/include/hipfort/amdgcn "-DHIPFORT_ARCH=\"amd\"" -L$HIPFORT_HOME/lib -lhipfort-amdgcn $LIB_FLAGS -o main <fortran_code>.o hip_kernels.o

This option gives enough flexibility for calling HIP libraries from Fortran or for a mix of OpenMP/OpenACC offloading to GPUs and HIP kernels/libraries.

Examples: saxpy and pi

There are two examples for exploring.

The first one saxpy demonstrates a basic memory management and how to call from fortran a hip kernel. For reference, file cuda-fortran/main.cuf contains an equivalent CUDA Fortran code.

Hipfort provides interfaces for various highly optimized library.

The folder hiprand_example shows how to call the hiprand for generating single precision uniform random distributed nubmbers for calculation the value of pi.

The exercise is to analyse and run the programs. For more examples of hipfort check also the official repository.

Heat Equation

Starting from the Fortran, serial or MPI, heat equation offload to GPU the update loops.