{"id":78157,"date":"2014-05-08T14:53:58","date_gmt":"2014-05-08T18:53:58","guid":{"rendered":"http:\/\/www.bu.edu\/tech\/?page_id=78157"},"modified":"2025-05-02T15:33:46","modified_gmt":"2025-05-02T19:33:46","slug":"compilers","status":"publish","type":"page","link":"https:\/\/www.bu.edu\/tech\/support\/research\/software-and-programming\/programming\/compilers\/","title":{"rendered":"Compilers"},"content":{"rendered":"

On the SCC, there are currently four families of compilers: GNU, LLVM, Nvidia (PGI), and Intel. They are used for compiling C, C++, and Fortran codes. Nvidia purchased The Portland Group company, the original authors of the PGI compilers, in 2013.<\/p>\n

The GNU compilers are automatically available after logging onto the SCC. On the AlmaLinux 8 operating system the default GNU compiler version is 8.5.0. To switch to a different compiler, use the module command:<\/p>\n

scc1$<\/span> module load<\/span> intel\/2024.0    # example - load the Intel compilers<\/span>\r\n<\/code><\/pre>\n
If you are compiling software that uses MPI, the best practice is to load the compiler you want to use followed by the matching OpenMPI module:<\/p>\n
scc1$<\/span> module load<\/span> nvidia-hpc\/2023-23.5    # example - use the Nvidia compilers with OpenMPI<\/span>\r\nscc1$<\/span> module load<\/span> openmpi\/4.1.5_nvidia-2023-23.5\r\n<\/code><\/pre>\n
The compiler commands and module names for the four compilers are listed in the following table. There is a module for older versions of the PGI compilers called pgi<\/code>, but it is recommended that the nvidia-hpc<\/code> module be used instead for more up-to-date compilers:<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Language<\/th>\nDeveloper<\/th>\nModule Name<\/th>\nCommand<\/th>\n<\/tr>\n
Fortran 77<\/td>\nGNU<\/td>\ngcc<\/td>\ngfortran<\/td>\n<\/tr>\n
Fortran 90\/95\/03<\/td>\nGNU<\/td>\ngcc<\/td>\ngfortran<\/td>\n<\/tr>\n
C<\/td>\nGNU<\/td>\ngcc<\/td>\ngcc (cc)<\/td>\n<\/tr>\n
C++<\/td>\nGNU<\/td>\ngcc<\/td>\ng++ (c++)<\/td>\n<\/tr>\n
Fortran 77<\/td>\nNvidia\/PGI<\/td>\nnvidia-hpc or<\/em> pgi<\/td>\npgfortran (pgf77)<\/td>\n<\/tr>\n
Fortran 90\/95\/03<\/td>\nNvidia\/PGI<\/td>\nnvidia-hpc or<\/em> pgi<\/td>\npgfortran (pgf90, pgf95)
\n<\/sup><\/td>\n<\/tr>\n
C<\/td>\nNvidia\/PGI<\/td>\nnvidia-hpc or<\/em> pgi<\/td>\npgcc<\/td>\n<\/tr>\n
C++<\/td>\nNvidia\/PGI<\/td>\nnvidia-hpc or<\/em> pgi<\/td>\npgc++<\/td>\n<\/tr>\n
Fortran 77\/90\/95\/03<\/td>\nIntel<\/td>\nintel<\/td>\nifort or<\/em> ifx 1<\/sup><\/td>\n<\/tr>\n
C<\/td>\nIntel<\/td>\nintel<\/td>\nicc or<\/em> icx 1<\/sup><\/td>\n<\/tr>\n
C++<\/td>\nIntel<\/td>\nintel<\/td>\nicpc or<\/em> icpx 1<\/sup><\/td>\n<\/tr>\n
C<\/td>\nLLVM<\/td>\nllvm<\/td>\nclang<\/td>\n<\/tr>\n
C++<\/td>\nLLVM<\/td>\nllvm<\/td>\nclang++<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
1<\/strong><\/sup> The Intel compiler modules older than intel\/2023.1<\/code> provide the icc, icpc, and ifort compilers. The intel\/2023.1<\/code> module also provides a new family of compilers: icx, icpx, and ifx.\u00a0 Intel compiler modules installed after<\/strong> intel\/2023.1<\/code> will only provide these new compilers as the “classic” ones (icc, icpc, ifort) have been retired by Intel.<\/p>\n
For all of the compilers see Multiprocessor Programming<\/a> documentation for compiling OpenMP and MPI codes.<\/p>\n
GNU and LLVM compilers<\/h2>\n
Here are some examples of commonly used flags applicable to gcc, g++, and gfortran<\/code> compilers. The LLVM clang and clang++ compilers use nearly identical flags to the GNU compilers:<\/p>\n
scc1$<\/span> module load gcc\/12.2.0 <\/span>\r\nscc1$<\/span> man<\/span> gcc                 # gcc manual (help) page<\/span>\r\nscc1$<\/span> gcc<\/span> --help              # concise options help file<\/span>\r\nscc1$<\/span> gcc<\/span> -o file-name<\/span> ...    # executable name<\/span>\r\nscc1$<\/span> gcc<\/span> -On ...             # code optimization; n=0,1,2,3<\/span>\r\nscc1$<\/span> gcc<\/span> -g ...              # debug mode<\/span>\r\nscc1$<\/span> gcc<\/span> -Warray-bounds ...  # arrays bound checking<\/span>\r\nscc1$<\/span> gcc<\/span> -pg ...             # profiling<\/span>\r\n<\/code><\/pre>\n
Intel compilers<\/h2>\n
Here are some examples of commonly used flags applicable to icc, icpc, ifort<\/code> compilers:<\/p>\n
scc1$<\/span> module load intel\/2024.0 <\/span>\r\nscc1$<\/span> man<\/span> icx # icxmanual page<\/span>\r\nscc1$<\/span> icx<\/span> -help            # concise options help file<\/span>\r\nscc1$<\/span> icx<\/span> -o file-name<\/span> ... # executable name<\/span>\r\nscc1$<\/span> icx<\/span> -On ...          # code optimization; n=0,1,2,3,4,fast; recommends 3<\/span>\r\nscc1$<\/span> icx<\/span> -fast ...        # accelerate the program<\/span>\r\nscc1$<\/span> icx<\/span> -g ...           # debug mode<\/span>\r\nscc1$<\/span> icx<\/span> -p ...           # profiling (-pg is also valid)<\/span><\/code><\/pre>\n
Nvidia\/PGI compilers<\/h2>\n
Here are some examples of commonly used flags applicable to pgcc, pgc++, pgfortran<\/code> compilers:<\/p>\n
scc1$<\/span> module load nvidia-hpc\/2023-23.5 <\/span>\r\nscc1$<\/span> man<\/span> pgcc              # pgfortran manual (help) page<\/span>\r\nscc1$<\/span> pgcc<\/span> -help            # concise options help file<\/span>\r\nscc1$<\/span> pgcc<\/span> -o file-name<\/span> ... # executable name<\/span>\r\nscc1$<\/span> pgcc<\/span> -On ...          # code optimization; n=0,1,2,3,4,fast; recommends 3<\/span>\r\nscc1$<\/span> pgcc<\/span> -g ...           # debug mode<\/span>\r\nscc1$<\/span> pgcc<\/span> -pg ...          # profiling<\/span>\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
On the SCC, there are currently four families of compilers: GNU, LLVM, Nvidia (PGI), and Intel. They are used for compiling C, C++, and Fortran codes. Nvidia purchased The Portland Group company, the original authors of the PGI compilers, in 2013. The GNU compilers are automatically available after logging onto the SCC. On the AlmaLinux…<\/p>\n","protected":false},"author":1692,"featured_media":0,"parent":64953,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/78157"}],"collection":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/users\/1692"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/comments?post=78157"}],"version-history":[{"count":50,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/78157\/revisions"}],"predecessor-version":[{"id":157142,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/78157\/revisions\/157142"}],"up":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/64953"}],"wp:attachment":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/media?parent=78157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}