However, I'm having problems compiling the same program in a PowerPC
system (64-bit). It seems to me that the -mcmodel=medium only applies
for x86-64 systems.
That is correct.
I have been using -mpowerpc64 to ensure it compiles a 64-bit
version for
the PowerPC, but I don't know how (or if it's possible) to address
more
than 2Gb of static memory in this architecture.
-mpowerpc64 enables the use of 64-bit instructions, and treats the
general purpose registers as 64-bit; it does not make your program
a 64-bit program, use -m64 for that.
Segher