How to (zerop #*000) in common lisp?

Here's an option:

(defun bit-vector-zerop (bit-vector)
  (not (find 1 bit-vector)))

This does not cons and is very efficient on SBCL. It's faster if you can declare the argument to be a bit-vector.

I am not sure if there is any special bit logic function, see e.g. here.

But how about this?

(loop
  for bit across #*0000
  never (= bit 1))

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