On Oct 13, 2009, at 14:08, vincent habchi wrote: > The Atlas port is not universal. I would like to tweak that, but in > order to do this, I need to know before if gfortran 4.3 can > generated 32 or 64-bit binaries, in other words if it accepts -m32 > or -m64 flags. I'm not sure. Have you tried it, or asked the developers of gfortran?