Not sure whether this has to do with the other one. I am on another machine, it is GNU Emacs 26.3 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.20) of 2020-05-17, modified by Debian Anyway, I do this: 2 RET ;; display in hexa d 6 RET ;; Raise to the power 32 32 ^ ;; Shitf right by 30 C-u 32 b r ;; I get 0, whereas I expected 4 I have the impression that the old bigpos bigneg lisp based big intergers have been replaced by C bigintegers, and this is the root of all these regression. Well, just a speculation. V.