;;; The :full-call assembly-routines must use the same full-call
;;; unknown-values return convention as a normal call, as some
;;; of the routines will tail-chain to a static-function. The
;;; routines themselves, however, take all of their arguments
;;; in registers (this will typically be one or two arguments,
;;; and is one of the lower bounds on the number of argument-
;;; passing registers), and thus don't need a call frame, which
;;; simplifies things for the normal call/return case. When it
;;; is necessary for one of the assembly-functions to call a
;;; static-function it will construct the required call frame.
;;; Also, none of the assembly-routines return other than one
;;; value, which again simplifies the return path.
;;;    -- AB, 2006/Feb/05.