First implementation of gromacs + hipsycl.

[dipietrantonio]

This has not been completely tested as hipsycl requires Gromacs to be compiled with hipcc, and rocm/5.2.3 has not complete C++17 support (required by GROMACS).

Also, the package modifications to HIPSYCL and GROMACS could be improved, this was just an experiment.

To continue when we have a better ROCm version.

[al42and]

Hi!

This has not been completely tested as hipsycl requires Gromacs to be compiled with hipcc, and rocm/5.2.3 has not complete C++17 support (required by GROMACS).

I don't think that's correct.

First, GROMACS requires building with amdclang (or any recent clang; the mainline Clang 14 or newer works fine), not hipcc. I guess hipcc can work, since it's just a wrapper, but we haven't evaluated it.

Second, LUMI also has ROCm 5.2.3, and it works fine there, see Lumi-supercomputer/LUMI-EasyBuild-contrib#120.

I believe the problem is not with Clang or ROCm themselves, but with the libstdc++. The SLES15-based Cray systems have an old version of it installed system-wide, and it gets picked up by GROMACS. I believe that here two solutions are possible:

• like LUMI, use -D CMAKE_CXX_FLAGS="--gcc-toolchain=/opt/cray/pe/gcc/11.2.0/snos/" to point to the system-wide libstdc++, or
• install GCC 9 or newer with Spack, and make sure it is available in PATH, without any symlinks and the like, so that GROMACS can automatically detect it (or supply it via -DGMX_GPLUSPLUS_PATH).