[Sbcl-devel] sxhash depends only on array rank?

[JTK <je...@gm...>]

Apologies if this is an inane question, but is the following intended?

cl-user> (lisp-implementation-version)
"1.2.11"
cl-user> (sxhash #(2))
1193941381096739655
cl-user> (sxhash #(1 2))
1193941381096739655
cl-user> (sxhash #(3 1 2))
1193941381096739655
cl-user> (sxhash #())
1193941381096739655
cl-user> (sxhash (vector "bunny"))
1193941381096739655

Admittedly, it conforms with CLHS http://www.lispworks.com/documentation/lw61/CLHS/Body/f_sxhash.htm <http://www.lispworks.com/documentation/lw61/CLHS/Body/f_sxhash.htm>

It comes from target-sxhash.lisp where 


(array ;; case of array
               (typecase x
                 (simple-string (sxhash x)) ; through DEFTRANSFORM
                 ;;; falls through to here
                 (t (logxor 191020317 (sxhash (array-rank x))))))


So every 1d array has the same sxhash.  Is there a reason the first few elements aren’t used,
like for a list?