GNU Compiler Collection (GCC)¶

Supported versions¶

To check which GCC versions are currently supported on Discoverer, execute on the login node:

module avail gcc

The recipe, developed to carry on the compilation of the GCC code on Discoverer HPC, is publicly available online at:

https://gitlab.discoverer.bg/vkolev/recipes/-/tree/main/gcc

Loading¶

To obtain access to the latest GCC, load the environment module gcc/latest:

module load gcc/latest

otherwise replace latest with the reqired version.

Compilers¶

Host/Target specification¶

The provided GNU Compiler Collection matches the following host/target specification:

x86_64-pc-linux-gnu

More about the host and target specifications:

https://gcc.gnu.org/install/specific.html

Classic compilers¶

Warning

GCC provides classic compilers only!

gcc
g++
gfortran

Libraries embedded¶

All available GCC builds embed the following libraries:

GNU MPFR (GNU C library for arbitrary-precision floating-point arithmetic)

GNU GMP (GNU Multiple Precision Arithmetic Library)

GNU MPC (C library for the arithmetic of complex numbers)

ISL (thread-safe C library for manipulating sets and relations of integer points bounded by affine constraints)

which means you do not need to load those libraries explicitly through any other environment module. If the GCC environment module is loaded, that means the shared and static versions of those libraries become accessible from within the user environment.

Compiler optimization flags for AMD Zen2 CPU¶

Note

The compute nodes of Dicoverer HPC are equipped with AMD EPYC 7H12 64-Core processors, which implies AMD Zen2 CPU architecture.

The following compiler flags can be useful during the compile-time optimization of your binary code on AMD Zen2:

-march=znver2 -mtune=native

For example:

gcc -march=znver2 -mtune=native ...
g++ -march=znver2 -mtune=native ...
gfortran -march=znver2 -mtune=native ...

More on the supported compiler flags: AMD EPYC™ 7xx2-series Processors Compiler Options Quick Reference Guide

Interaction with CMake¶

It is recommended to specify the compiler executables when invoking cmake tool:

-DCMAKE_C_COMPILER=gcc
-DCMAKE_CXX_COMPILER=g++
-DCMAKE_Fortran_COMPILER=gfortran

The corresponding optimization compiler flags can be passed to cmake as well:

-DCMAKE_C_FLAGS="-march=znver2 -mtune=native"
-DCMAKE_CXX_FLAGS="-march=znver2 -mtune=native"
-DCMAKE_Fortran_FLAGS="-march=znver2 -mtune=native"

Getting help¶

See Getting help