+#!+compare-and-swap-vops
+(define-vop (%compare-and-swap-svref word-index-cas)
+ (:note "inline array compare-and-swap")
+ (:policy :fast-safe)
+ (:variant vector-data-offset other-pointer-lowtag)
+ (:translate %compare-and-swap-svref)
+ (:arg-types simple-vector positive-fixnum * *))