You can use double-doubles for near-128-bit floating point [1]. It's much more powerful than 53.53 fixed point you mentioned, but more complicated as well. [1]

You can use double-doubles for near-128-bit floating point [1]. It's much more powerful than 53.53 fixed point you mentioned, but more complicated as well. [1] http://web.mit.edu/tabbott/Public/quaddouble-debian/qd-2.3.4-old/docs/qd.pdf http://web.mit.edu/tabbott/Public/quaddouble-debian/qd-2.3.4...