const diff = if (order == .asc) b_int - a_int else a_int - b_int;
const sign_bit: u1 = @truncate(@as(UWInt, @bitCast(diff)) >> @intCast(bits));
var mask_word = @as(usize, 0) -% @as(usize, sign_bit);
Radix sort also seems to fit the bill?
Wow, this is jam-packed with interesting information. Thanks for writing it! (Also thanks for all of your other great open source work!)
Are there plans to upstream this into the Zig std library? Seems like it could be useful for more than just the cryptography package, since the benchmarks at the end have it often being faster than std pdqsort. I just checked the issue trackers on Codeberg and GitHub, and didn't see anything mentioning djbsort or NTRU Prime, which leads me to believe there aren't (official) plans to upstream this (yet).