Compiler(Hawk)

We highly recommend to try as much different compilers as possible and compare the performance of the generated code! If you code according to language standards, this is almost for free but can give you a significant speedup! There is no such thing as an "ideal" compiler! One suites better to application A, one suites better to application B (cf. Best Practice Guide AMD EPYC (Naples)).

Please note that compilers do not use optimization flags by default at the moment. Hence, please refer to Compiler Options Quick Reference Guide and set the respective flags on your own (with znver1 for Naples and znver2 for Rome nodes). Compiler Usage Guidelines for AMD64 Platforms might also be a source of inspiration w.r.t. optimization flags.

GNU

Make sure to load a more up to date version of the GNU Compiler Collection than the one preinstalled in the system

module load compiler/gnu/9.1.0

Then compile with

<compiler> -march=znver2

AOCC

AOCC is the AMD Optimizing C/C++ Compiler based on LLVM. It contains a Fortran compiler (flang) as well.

Load aocc module

module load compiler/aocc/2.0.0

Compile with

clang/clang++/flang -march=znver2

AOCC comes with a couple of exclusive compiler flags that are not part of LLVM and allow more aggressive optimizations, they are listed in the C/C++ and Fortran compiler manual.

Intel

Please use

<compiler> -march=core-avx2

and do not use

<compiler> -xCORE-AVX2

since the latter might give very bad performance!

PGI

With respect to PGI, we recommend to use

<compiler> -tp=zen -O3