move.lisp

开源跨平台Lisp编译器

;;; This VOP exists just to begin the lifetime of a TN that couldn't
;;; be written legally due to a type error. An error is signalled
;;; before this VOP is so we don't need to do anything (not that there
;;; would be anything sensible to do anyway.)
(define-vop (illegal-move)
  (:args (x) (type))
  (:results (y))
  (:ignore y)
  (:vop-var vop)
  (:save-p :compute-only)
  (:generator 666
    (error-call vop 'object-not-type-error x type)))

;;;; moves and coercions

;;; These MOVE-TO-WORD VOPs move a tagged integer to a raw full-word
;;; representation. Similarly, the MOVE-FROM-WORD VOPs converts a raw
;;; integer to a tagged bignum or fixnum.

;;; Arg is a fixnum, so just shift it. We need a type restriction
;;; because some possible arg SCs (control-stack) overlap with
;;; possible bignum arg SCs.
(define-vop (move-to-word/fixnum)
  (:args (x :scs (any-reg descriptor-reg) :target y
            :load-if (not (location= x y))))
  (:results (y :scs (signed-reg unsigned-reg)
               :load-if (not (location= x y))))
  (:arg-types tagged-num)
  (:note "fixnum untagging")
  (:generator 1
    (move y x)
    (inst sar y  (1- n-lowtag-bits))))
(define-move-vop move-to-word/fixnum :move
  (any-reg descriptor-reg) (signed-reg unsigned-reg))

;;; Arg is a non-immediate constant, load it.
(define-vop (move-to-word-c)
  (:args (x :scs (constant)))
  (:results (y :scs (signed-reg unsigned-reg)))
  (:note "constant load")
  (:generator 1
    (inst mov y (tn-value x))))
(define-move-vop move-to-word-c :move
  (constant) (signed-reg unsigned-reg))


;;; Arg is a fixnum or bignum, figure out which and load if necessary.
(define-vop (move-to-word/integer)
  (:args (x :scs (descriptor-reg) :target eax))
  (:results (y :scs (signed-reg unsigned-reg)))
  (:note "integer to untagged word coercion")
  (:temporary (:sc unsigned-reg :offset eax-offset
                   :from (:argument 0) :to (:result 0) :target y) eax)
  (:generator 4
    (move eax x)
    (inst test al-tn 7)                 ; a symbolic constant for this
    (inst jmp :z FIXNUM)                ; would be nice
    (loadw y eax bignum-digits-offset other-pointer-lowtag)
    (inst jmp DONE)
    FIXNUM
    (inst sar eax (1- n-lowtag-bits))
    (move y eax)
    DONE))
(define-move-vop move-to-word/integer :move
  (descriptor-reg) (signed-reg unsigned-reg))


;;; Result is a fixnum, so we can just shift. We need the result type
;;; restriction because of the control-stack ambiguity noted above.
(define-vop (move-from-word/fixnum)
  (:args (x :scs (signed-reg unsigned-reg) :target y
            :load-if (not (location= x y))))
  (:results (y :scs (any-reg descriptor-reg)
               :load-if (not (location= x y))))
  (:result-types tagged-num)
  (:note "fixnum tagging")
  (:generator 1
    (cond ((and (sc-is x signed-reg unsigned-reg)
                (not (location= x y)))
           ;; Uses 7 bytes, but faster on the Pentium
           (inst lea y (make-ea :qword :index x :scale 8)))
          (t
           ;; Uses: If x is a reg 2 + 3; if x = y uses only 3 bytes
           (move y x)
           (inst shl y (1- n-lowtag-bits))))))
(define-move-vop move-from-word/fixnum :move
  (signed-reg unsigned-reg) (any-reg descriptor-reg))

;;; Convert an untagged signed word to a lispobj -- fixnum or bignum
;;; as the case may be. Fixnum case inline, bignum case in an assembly
;;; routine.
(define-vop (move-from-signed)
  (:args (x :scs (signed-reg unsigned-reg) :to :result))
  (:results (y :scs (any-reg descriptor-reg) :from :argument))
  (:note "signed word to integer coercion")
  ;; Worst case cost to make sure people know they may be number consing.
  (:generator 20
     (aver (not (location= x y)))
     (let ((done (gen-label)))
       (inst imul y x #.(ash 1 n-fixnum-tag-bits))
       (inst jmp :no done)
       (inst mov y x)
       (inst lea temp-reg-tn
             (make-ea :qword :disp
                      (make-fixup (ecase (tn-offset y)
                                    (#.rax-offset 'alloc-signed-bignum-in-rax)
                                    (#.rcx-offset 'alloc-signed-bignum-in-rcx)
                                    (#.rdx-offset 'alloc-signed-bignum-in-rdx)
                                    (#.rbx-offset 'alloc-signed-bignum-in-rbx)
                                    (#.rsi-offset 'alloc-signed-bignum-in-rsi)
                                    (#.rdi-offset 'alloc-signed-bignum-in-rdi)
                                    (#.r8-offset  'alloc-signed-bignum-in-r8)
                                    (#.r9-offset  'alloc-signed-bignum-in-r9)
                                    (#.r10-offset 'alloc-signed-bignum-in-r10)
                                    (#.r12-offset 'alloc-signed-bignum-in-r12)
                                    (#.r13-offset 'alloc-signed-bignum-in-r13)
                                    (#.r14-offset 'alloc-signed-bignum-in-r14)
                                    (#.r15-offset 'alloc-signed-bignum-in-r15))
                                  :assembly-routine)))
       (inst call temp-reg-tn)
       (emit-label done))))
(define-move-vop move-from-signed :move
  (signed-reg) (descriptor-reg))

;;; Convert an untagged unsigned word to a lispobj -- fixnum or bignum
;;; as the case may be. Fixnum case inline, bignum case in an assembly
;;; routine.
(define-vop (move-from-unsigned)
  (:args (x :scs (signed-reg unsigned-reg) :to :result))
  (:results (y :scs (any-reg descriptor-reg) :from :argument))
  (:note "unsigned word to integer coercion")
  ;; Worst case cost to make sure people know they may be number consing.
  (:generator 20
    (aver (not (location= x y)))
    (let ((done (gen-label)))
      (inst mov y #.(ash lowtag-mask (- n-word-bits n-fixnum-tag-bits 1)))
      ;; The assembly routines test the sign flag from this one, so if
      ;; you change stuff here, make sure the sign flag doesn't get
      ;; overwritten before the CALL!
      (inst test x y)
      ;; Faster but bigger then SHL Y 4. The cost of doing this
      ;; speculatively should be noise compared to bignum consing if
      ;; that is needed and saves one branch.
      (inst lea y (make-ea :qword :index x :scale 8))
      (inst jmp :z done)
      (inst mov y x)
      (inst lea temp-reg-tn
            (make-ea :qword :disp
                     (make-fixup (ecase (tn-offset y)
                                   (#.rax-offset 'alloc-unsigned-bignum-in-rax)
                                   (#.rcx-offset 'alloc-unsigned-bignum-in-rcx)
                                   (#.rdx-offset 'alloc-unsigned-bignum-in-rdx)
                                   (#.rbx-offset 'alloc-unsigned-bignum-in-rbx)
                                   (#.rsi-offset 'alloc-unsigned-bignum-in-rsi)
                                   (#.rdi-offset 'alloc-unsigned-bignum-in-rdi)
                                   (#.r8-offset  'alloc-unsigned-bignum-in-r8)
                                   (#.r9-offset  'alloc-unsigned-bignum-in-r9)
                                   (#.r10-offset 'alloc-unsigned-bignum-in-r10)
                                   (#.r12-offset 'alloc-unsigned-bignum-in-r12)
                                   (#.r13-offset 'alloc-unsigned-bignum-in-r13)
                                   (#.r14-offset 'alloc-unsigned-bignum-in-r14)
                                   (#.r15-offset 'alloc-unsigned-bignum-in-r15))
                                 :assembly-routine)))
      (inst call temp-reg-tn)
      (emit-label done))))
(define-move-vop move-from-unsigned :move
  (unsigned-reg) (descriptor-reg))

;;; Move untagged numbers.
(define-vop (word-move)
  (:args (x :scs (signed-reg unsigned-reg) :target y
            :load-if (not (location= x y))))
  (:results (y :scs (signed-reg unsigned-reg)
               :load-if
               (not (or (location= x y)
                        (and (sc-is x signed-reg unsigned-reg)
                             (sc-is y signed-stack unsigned-stack))))))
  (:effects)
  (:affected)
  (:note "word integer move")
  (:generator 0
    (move y x)))
(define-move-vop word-move :move
  (signed-reg unsigned-reg) (signed-reg unsigned-reg))

;;; Move untagged number arguments/return-values.
(define-vop (move-word-arg)
  (:args (x :scs (signed-reg unsigned-reg) :target y)
         (fp :scs (any-reg) :load-if (not (sc-is y sap-reg))))
  (:results (y))
  (:note "word integer argument move")
  (:generator 0
    (sc-case y
      ((signed-reg unsigned-reg)
       (move y x))
      ((signed-stack unsigned-stack)
       (if (= (tn-offset fp) esp-offset)
           (storew x fp (tn-offset y))  ; c-call
           (storew x fp (- (1+ (tn-offset y)))))))))
(define-move-vop move-word-arg :move-arg
  (descriptor-reg any-reg signed-reg unsigned-reg) (signed-reg unsigned-reg))

;;; Use standard MOVE-ARG and coercion to move an untagged number
;;; to a descriptor passing location.
(define-move-vop move-arg :move-arg
  (signed-reg unsigned-reg) (any-reg descriptor-reg))