(:result-types unsigned-num)
(:generator 4
(inst xadd (make-ea :qword :base array
- :scale 1 :index index
+ :scale (ash 1 (- word-shift n-fixnum-tag-bits))
+ :index index
:disp (- (* vector-data-offset n-word-bytes)
other-pointer-lowtag))
diff :lock)