The question was "The FPU instruction set is the same", to which the response my response is correct, the same architecture can have different ABIs on different

The question was "The FPU instruction set is the same", to which the response my response is correct, the same architecture can have different ABIs on different systems. For example on osx it is 80bit ieee, but on win64 it is a 64bit ieee. That ABI difference means that having the same instruction set is not the only thing that matters.