+(define-vop (raw-instance-init/word)
+ (:args (object :scs (descriptor-reg))
+ (value :scs (unsigned-reg)))
+ (:arg-types * unsigned-num)
+ (:info instance-length index)
+ (:generator 5
+ (inst mov (make-ea-for-raw-slot object index instance-length 1) value)))
+
+(define-vop (raw-instance-atomic-incf/word)
+ (:translate %raw-instance-atomic-incf/word)
+ (:policy :fast-safe)
+ (:args (object :scs (descriptor-reg))
+ (index :scs (any-reg immediate))
+ (diff :scs (signed-reg) :target result))
+ (:arg-types * tagged-num signed-num)
+ (:temporary (:sc unsigned-reg) tmp)
+ (:results (result :scs (unsigned-reg)))
+ (:result-types unsigned-num)
+ (:generator 5
+ (loadw tmp object 0 instance-pointer-lowtag)
+ (inst shr tmp n-widetag-bits)
+ (when (sc-is index any-reg)
+ (inst shl tmp 2)
+ (inst sub tmp index))
+ (inst xadd (make-ea-for-raw-slot object index tmp 1) diff :lock)
+ (move result diff)))
+