;;; Boxed-Reg: any boxed register (any boxed object)
;;; Unboxed-Reg: any unboxed register (any unboxed object)
;;; Float-Reg, Double-Float-Reg: float in FP register.
;;; Boxed-Reg: any boxed register (any boxed object)
;;; Unboxed-Reg: any unboxed register (any unboxed object)
;;; Float-Reg, Double-Float-Reg: float in FP register.