Fortran, C and C++ compilers produced by the GNU Project.
Availability and Restrictions
Versions
The GNU Compiler Collection (GCC) are available on all our clusters. These are the versions currently available:
| Version | Pitzer | Ascend | Cardinal | Notes |
|---|---|---|---|---|
| 4.8.5 | X# | **See note below. | ||
| 7.3.0 | X | |||
| 8.1.0 | X | |||
| 8.4.0 | X | The variant supporting OpenMP and OpenACC offload is available. See the GPU offloading section below |
||
| 9.1.0 | X* | X | ||
| 10.3.0 | X | X | ||
| 11.2.0 | X | X* | ||
| 11.3.0 | X# | |||
| 12.3.0 | X | X | X* | |
| 13.2.0 | X |
# System version
Modules
| Systems | Module Name |
|---|---|
| Pitzer and Ascend | gnu |
| Cardinal | gcc |
You can use module spider <module name> to view available modules for a given machine. Feel free to contact OSC Help if you need other versions for your work.
To find out what version of gcc you are using, type gcc --version.
Access
The GNU compilers are available to all OSC users. If you have any questions, please contact OSC Help.
Publisher/Vendor/Repository and License Type
https://www.gnu.org/software/gcc/, Open source
Usage
Usage on Pitzer
Set-up
module load gnu. The default version will be loaded. To select a particular GNU version, use module load gnu/version. For example, use module load gnu/8.1.0 to load GNU 8.1.0.How to Compile
Once the module is loaded, follow the guides below for compile commands:
| LANGUAGE | NON-MPI | MPI |
|---|---|---|
| Fortran 90 or 95 | gfortran |
mpif90 |
| Fortran 77 | gfortran |
mpif77 |
| c | gcc |
mpicc |
| c++ | g++ |
mpicxx |
Building Options
The GNU compilers recognize the following command line options :
| COMPILER OPTION | PURPOSE |
|---|---|
-fopenmp |
Enables compiler recognition of OpenMP directives (except mpif77) |
-o FILENAME |
Specifies the name of the object file |
-O0 or no -O option |
Disable optimization |
-O1 or -O |
Ligh optimization |
-O2 |
Heavy optimization |
-O3 |
Most expensive optimization (Recommended) |
There are numerous flags that can be used. For more information run man <compiler binary name>.
Known Issues
GCC 13 compilation errors due to missing headers
Type mismatch error
GNU compiler versions 10+ may have Fortran compiler errors like
Error: Type mismatch between actual argument at (1) and actual argument at (2) (REAL(4)/REAL(8))
that result in a error response during configuration
configure: error: The Fortran compiler gfortran will not compile files that call the same routine with arguments of different types.
This can be caused when codes are using types that don't match the subroutine arguement types. The mismatches are now reject with an error to warn about future errors that may occur. It is bypassable by appending the -fallow-argument-mismatch arguement while calling gfortran.
Multiple definition error
GNU compiler versions 10+ may have C compiler errors like
/.libs/libmca_mtl_psm.a(mtl_psm_component.o): multiple definition of `mca_mtl_psm_component'
This is a common mistake in C is omitting extern when declaring a global variable in a header file. In previous GCC versions this error is ignored. GCC 10 defaults to -fno-common, which means a linker error will now be reported. It is bypassable by appending the -fcommon to compilation flags.
