+(define-vop (fsqrt)
+ (:args (x :scs (double-reg)))
+ (:results (y :scs (double-reg)))
+ (:translate %sqrt)
+ (:policy :fast-safe)
+ (:arg-types double-float)
+ (:result-types double-float)
+ (:note "inline float arithmetic")
+ (:vop-var vop)
+ (:save-p :compute-only)
+ (:generator 1
+ (note-this-location vop :internal-error)
+ (inst sqrtsd y x)))