Effect of -g on libmpi.so

I'm realizing that including -g in my compile statement causes my MPI C++ program executable to link with libmpi_dbg.so.4 rather than libmpi.so.4 (v13/impi/4.1.0.024/lib64). Can anyone explain exactly why that is so and whether there is necessarily an associated impact on performance?

A simple C++ code calling only MPI_Init compiled with mpicxx and with or without -g is sufficient to demonstrate the behavior.