sap.lisp

开源跨平台Lisp编译器

;;;; the Alpha VM definition of SAP operations

;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;;
;;;; This software is derived from the CMU CL system, which was
;;;; written at Carnegie Mellon University and released into the
;;;; public domain. The software is in the public domain and is
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.

(in-package "SB!VM")

;;;; moves and coercions

;;; Move a tagged SAP to an untagged representation.
(define-vop (move-to-sap)
  (:args (x :scs (descriptor-reg)))
  (:results (y :scs (sap-reg)))
  (:note "system area pointer indirection")
  (:generator 1
    (loadq y x sap-pointer-slot other-pointer-lowtag)))
(define-move-vop move-to-sap :move
  (descriptor-reg) (sap-reg))

;;; Move an untagged SAP to a tagged representation.
(define-vop (move-from-sap)
  (:args (x :scs (sap-reg) :target sap))
  (:temporary (:scs (sap-reg) :from (:argument 0)) sap)
  (:temporary (:scs (non-descriptor-reg)) ndescr)
  (:results (y :scs (descriptor-reg)))
  (:note "system area pointer allocation")
  (:generator 20
    (move x sap)
    (with-fixed-allocation (y ndescr sap-widetag sap-size)
      (storeq sap y sap-pointer-slot other-pointer-lowtag))))
(define-move-vop move-from-sap :move
  (sap-reg) (descriptor-reg))

;;; Move untagged SAP values.
(define-vop (sap-move)
  (:args (x :target y
            :scs (sap-reg)
            :load-if (not (location= x y))))
  (:results (y :scs (sap-reg)
               :load-if (not (location= x y))))
  (:effects)
  (:affected)
  (:generator 0
    (move x y)))
(define-move-vop sap-move :move
  (sap-reg) (sap-reg))

;;; Move untagged SAP arguments/return-values.
(define-vop (move-sap-arg)
  (:args (x :target y
            :scs (sap-reg))
         (fp :scs (any-reg)
             :load-if (not (sc-is y sap-reg))))
  (:results (y))
  (:generator 0
    (sc-case y
      (sap-reg
       (move x y))
      (sap-stack
       (storeq x fp (tn-offset y))))))
(define-move-vop move-sap-arg :move-arg
  (descriptor-reg sap-reg) (sap-reg))

;;; Use standard MOVE-ARG + coercion to move an untagged sap to a
;;; descriptor passing location.
(define-move-vop move-arg :move-arg
  (sap-reg) (descriptor-reg))

;;;; SAP-INT and INT-SAP

(define-vop (sap-int)
  (:args (sap :scs (sap-reg) :target int))
  (:arg-types system-area-pointer)
  (:results (int :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:translate sap-int)
  (:policy :fast-safe)
  (:generator 1
    (move sap int)))

(define-vop (int-sap)
  (:args (int :scs (unsigned-reg) :target sap))
  (:arg-types unsigned-num)
  (:results (sap :scs (sap-reg)))
  (:result-types system-area-pointer)
  (:translate int-sap)
  (:policy :fast-safe)
  (:generator 1
    (move int sap)))

;;;; POINTER+ and POINTER-

(define-vop (pointer+)
  (:translate sap+)
  (:args (ptr :scs (sap-reg))
         (offset :scs (signed-reg immediate)))
  (:arg-types system-area-pointer signed-num)
  (:results (res :scs (sap-reg)))
  (:result-types system-area-pointer)
  (:policy :fast-safe)
  (:generator 1
    (sc-case offset
      (signed-reg
       (inst addq offset ptr res))
      (immediate
       (inst lda res (tn-value offset) ptr)))))

(define-vop (pointer-)
  (:translate sap-)
  (:args (ptr1 :scs (sap-reg))
         (ptr2 :scs (sap-reg)))
  (:arg-types system-area-pointer system-area-pointer)
  (:policy :fast-safe)
  (:results (res :scs (signed-reg)))
  (:result-types signed-num)
  (:generator 1
    (inst subq ptr1 ptr2 res)))

;;;; mumble-SYSTEM-REF and mumble-SYSTEM-SET

(macrolet ((def-system-ref-and-set
             (ref-name set-name sc type size &optional signed)
             (let ((ref-name-c (symbolicate ref-name "-C"))
                   (set-name-c (symbolicate set-name "-C")))
               `(progn
                  (define-vop (,ref-name)
                    (:translate ,ref-name)
                    (:policy :fast-safe)
                    (:args (object :scs (sap-reg) :target sap)
                           (offset :scs (signed-reg)))
                    (:arg-types system-area-pointer signed-num)
                    ,@(when (or (eq size :byte) (eq size :short))
                        `((:temporary (:sc non-descriptor-reg) temp)
                          (:temporary (:sc non-descriptor-reg) temp1)))
                    (:results (result :scs (,sc)))
                    (:result-types ,type)
                    (:temporary (:scs (sap-reg) :from (:argument 0)) sap)
                    (:generator 5
                                (inst addq object offset sap)
                                ,@(ecase size
                                    (:byte
                                     (if signed
                                         '((inst ldq_u temp 0 sap)
                                           (inst lda temp1 1 sap)
                                           (inst extqh temp temp1 temp)
                                           (inst sra temp 56 result))
                                       '((inst ldq_u temp 0 sap)
                                         (inst lda temp1 0 sap)
                                         (inst extbl temp temp1 result))))
                                    (:short
                                     (if signed
                                         '((inst ldq_u temp 0 sap)
                                           (inst lda temp1 0 sap)
                                           (inst extwl temp temp1 temp)
                                           (inst sll temp 48 temp)
                                           (inst sra temp 48 result))
                                       '((inst ldq_u temp 0 sap)
                                         (inst lda temp1 0 sap)
                                         (inst extwl temp temp1 result))))
                                    (:long
                                     `((inst ldl result 0 sap)
                                       ,@(unless signed
                                           '((inst mskll result 4 result)))))
                                    (:quad
                                     '((inst ldq result 0 sap)))
                                    (:single
                                     '((inst lds result 0 sap)))
                                    (:double
                                     '((inst ldt result 0 sap))))))
                  (define-vop (,ref-name-c)
                    (:translate ,ref-name)
                    (:policy :fast-safe)
                    (:args (object :scs (sap-reg)))
                    (:arg-types system-area-pointer