Double-double: 31 digits of precision without leaving the FPU

AI has rediscovered https://www.davidhbailey.com/dhbsoftware/ and similar? Or are there algorithmic improvements? Without referencing established double-double work it's hard to know.

Fun fact - Google Maps does something similar to this in WebGL in order to keep accurate coordinates across a planet-sized map using only 32-bit floats.