I recently ported the wonderful geohash computation approach of https://mmcloughlin.com/posts/geohash-assembly https://mmcloughlin.com/posts/geohash-assembly in

I recently ported the wonderful geohash computation approach of https://mmcloughlin.com/posts/geohash-assembly https://mmcloughlin.com/posts/geohash-assembly into an OCaml CGI conversion webservice. There are so many subtle gems in that article, a pleasure to read. The bit-fiddling reminded me of invsqrt.