(define-vop (compare-and-swap-slot)
(:args (object :scs (descriptor-reg) :to :eval)
(old :scs (descriptor-reg any-reg) :target eax)
(define-vop (compare-and-swap-slot)
(:args (object :scs (descriptor-reg) :to :eval)
(old :scs (descriptor-reg any-reg) :target eax)