How to compile MPI with gcc?

Question

Does anyone know if it is possible to compile MPI with gcc?. I need to use gcc, no mpicc.

Answer 1

Yes, you can use gcc actually. But in my case (on Ubuntu) mpicc is just a wrapper of gcc, here is the output of command mpicc -showme:

gcc -I/usr/lib/openmpi/include/openmpi/opal/mca/event/libevent2021/libevent -I/usr/lib/openmpi/include/openmpi/opal/mca/event/libevent2021/libevent/include -I/usr/lib/openmpi/include -I/usr/lib/openmpi/include/openmpi -pthread -Wl,-rpath -Wl,/usr/lib/openmpi/lib -Wl,--enable-new-dtags -L/usr/lib/openmpi/lib -lmpi

While in Open MPI docs:

The Open MPI team strongly recommends that you simply use Open MPI's "wrapper" compilers to compile your MPI applications. That is, instead of using (for example) gcc to compile your program, use mpicc.

We repeat the above statement: the Open MPI Team strongly recommends that the use the wrapper compilers to compile and link MPI applications. If you find yourself saying, "But I don't want to use wrapper compilers!", please humor us and try them. See if they work for you. Be sure to let us know if they do not work for you. Many people base their "wrapper compilers suck!" mentality on bad behavior from poorly-implemented wrapper compilers in the mid-1990's. Things are much better these days; wrapper compilers can handle almost any situation, and are far more reliable than you attempting to hard-code the Open MPI-specific compiler and linker flags manually. That being said, there are some -- very, very few -- situations where using wrapper compilers can be problematic -- such as nesting multiple wrapper compilers of multiple projects. Hence, Open MPI provides a workaround to find out what command line flags you need to compile MPI applications.

Here this answer is useful for you.