You can set up your compiler flags when doinng the configure as follows:
CFLAGS="-DSCC -mcpu=pentium -static -gcc-version=340 -D_GNU_SOURCE" ./configure <your other options>
Then all your applications will get the corrent flags when compiling with mpic++, without extra options. This will save you some time and simplify your make files.
I have tested building applications without any of those flags with the following compilers (and their fortran counterparts where available):
GCC 3.4, 4.3 and 4.5
ICC 8.1 and 10.1
The MPICH2 code base has been written with portability in mind, that may be why omiting the options may be a non issue in RCKMPI in particular.
It would be great if someone behind RCKMPI could comment on this issue to say whether these options may be required.
RCKMPI is MPICH2 1.2.1p1 plus 3 custom SCC channels. The SCC channels were developed by me during my internship at Intel Labs Braunschweig.
I have never used those flags to compile the library or MPI applications. However, I would rather be careful before making statent on the effect of compiler flags.
Are you having issues with your MPI applications?