arith.lisp

开源跨平台Lisp编译器

;;;; the VM definition arithmetic VOPs for the Alpha

;;;; 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")

;;;; unary operations

(define-vop (fixnum-unop)
  (:args (x :scs (any-reg)))
  (:results (res :scs (any-reg)))
  (:note "inline fixnum arithmetic")
  (:arg-types tagged-num)
  (:result-types tagged-num)
  (:policy :fast-safe))

(define-vop (signed-unop)
  (:args (x :scs (signed-reg)))
  (:results (res :scs (signed-reg)))
  (:note "inline (signed-byte 64) arithmetic")
  (:arg-types signed-num)
  (:result-types signed-num)
  (:policy :fast-safe))

(define-vop (fast-negate/fixnum fixnum-unop)
  (:translate %negate)
  (:generator 1
    (inst subq zero-tn x res)))

(define-vop (fast-negate/signed signed-unop)
  (:translate %negate)
  (:generator 2
    (inst subq zero-tn x res)))

(define-vop (fast-lognot/fixnum fixnum-unop)
  (:translate lognot)
  (:generator 1
    (inst eqv x fixnum-tag-mask res)))

(define-vop (fast-lognot/signed signed-unop)
  (:translate lognot)
  (:generator 2
    (inst not x res)))

;;;; binary fixnum operations

;;; Assume that any constant operand is the second arg...

(define-vop (fast-fixnum-binop)
  (:args (x :target r :scs (any-reg))
         (y :target r :scs (any-reg)))
  (:arg-types tagged-num tagged-num)
  (:results (r :scs (any-reg)))
  (:result-types tagged-num)
  (:note "inline fixnum arithmetic")
  (:effects)
  (:affected)
  (:policy :fast-safe))

(define-vop (fast-unsigned-binop)
  (:args (x :target r :scs (unsigned-reg))
         (y :target r :scs (unsigned-reg)))
  (:arg-types unsigned-num unsigned-num)
  (:results (r :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:note "inline (unsigned-byte 64) arithmetic")
  (:effects)
  (:affected)
  (:policy :fast-safe))

(define-vop (fast-signed-binop)
  (:args (x :target r :scs (signed-reg))
         (y :target r :scs (signed-reg)))
  (:arg-types signed-num signed-num)
  (:results (r :scs (signed-reg)))
  (:result-types signed-num)
  (:note "inline (signed-byte 64) arithmetic")
  (:effects)
  (:affected)
  (:policy :fast-safe))

(define-vop (fast-fixnum-c-binop fast-fixnum-binop)
  (:args (x :target r :scs (any-reg)))
  (:info y)
  (:arg-types tagged-num (:constant integer)))

(define-vop (fast-signed-c-binop fast-signed-binop)
  (:args (x :target r :scs (signed-reg)))
  (:info y)
  (:arg-types signed-num (:constant integer)))

(define-vop (fast-unsigned-c-binop fast-unsigned-binop)
  (:args (x :target r :scs (unsigned-reg)))
  (:info y)
  (:arg-types unsigned-num (:constant integer)))

(defmacro define-binop (translate cost untagged-cost op
                        tagged-type untagged-type
                        &optional arg-swap restore-fixnum-mask)
  `(progn
     (define-vop (,(symbolicate "FAST-" translate "/FIXNUM=>FIXNUM")
                  fast-fixnum-binop)
       ,@(when restore-fixnum-mask
           `((:temporary (:sc non-descriptor-reg) temp)))
       (:args (x ,@(unless restore-fixnum-mask `(:target r)) :scs (any-reg))
              (y ,@(unless restore-fixnum-mask `(:target r)) :scs (any-reg)))
       (:translate ,translate)
       (:generator ,(1+ cost)
         ,(if arg-swap
              `(inst ,op y x ,(if restore-fixnum-mask 'temp 'r))
              `(inst ,op x y ,(if restore-fixnum-mask 'temp 'r)))
         ,@(when restore-fixnum-mask
             `((inst bic temp #.(ash lowtag-mask -1) r)))))
     (define-vop (,(symbolicate "FAST-" translate "/SIGNED=>SIGNED")
                  fast-signed-binop)
       (:args (x :target r :scs (signed-reg))
              (y :target r :scs (signed-reg)))
       (:translate ,translate)
       (:generator ,(1+ untagged-cost)
         ,(if arg-swap
              `(inst ,op y x r)
              `(inst ,op x y r))))
     (define-vop (,(symbolicate "FAST-" translate "/UNSIGNED=>UNSIGNED")
                  fast-unsigned-binop)
       (:args (x :target r :scs (unsigned-reg))
              (y :target r :scs (unsigned-reg)))
       (:translate ,translate)
       (:generator ,(1+ untagged-cost)
         ,(if arg-swap
              `(inst ,op y x r)
              `(inst ,op x y r))))
     ,@(when (and tagged-type (not arg-swap))
         `((define-vop (,(symbolicate "FAST-" translate "-C/FIXNUM=>FIXNUM")
                        fast-fixnum-c-binop)
             (:args (x ,@(unless restore-fixnum-mask `(:target r))
                       :scs (any-reg)))
             (:arg-types tagged-num (:constant ,tagged-type))
             ,@(when restore-fixnum-mask
                 `((:temporary (:sc non-descriptor-reg) temp)))
             (:translate ,translate)
             (:generator ,cost
                (inst ,op x (fixnumize y) ,(if restore-fixnum-mask 'temp 'r))
                ,@(when restore-fixnum-mask
                    `((inst bic temp #.(ash lowtag-mask -1) r)))))))
     ,@(when (and untagged-type (not arg-swap))
         `((define-vop (,(symbolicate "FAST-" translate "-C/SIGNED=>SIGNED")
                        fast-signed-c-binop)
             (:arg-types signed-num (:constant ,untagged-type))
             (:translate ,translate)
             (:generator ,untagged-cost
                (inst ,op x y r)))
           (define-vop (,(symbolicate "FAST-" translate
                                      "-C/UNSIGNED=>UNSIGNED")
                        fast-unsigned-c-binop)
             (:arg-types unsigned-num (:constant ,untagged-type))
             (:translate ,translate)
             (:generator ,untagged-cost
                (inst ,op x y r)))))))

(define-binop + 1 5 addq (unsigned-byte 6) (unsigned-byte 8))
(define-binop - 1 5 subq (unsigned-byte 6) (unsigned-byte 8))
(define-binop logand 1 3 and (unsigned-byte 6) (unsigned-byte 8))
(define-binop logandc1 1 3 bic (unsigned-byte 6) (unsigned-byte 8) t)
(define-binop logandc2 1 3 bic (unsigned-byte 6) (unsigned-byte 8))
(define-binop logior 1 3 bis (unsigned-byte 6) (unsigned-byte 8))
(define-binop logorc1 1 3 ornot (unsigned-byte 6) (unsigned-byte 8) t t)
(define-binop logorc2 1 3 ornot (unsigned-byte 6) (unsigned-byte 8) nil t)
(define-binop logxor 1 3 xor (unsigned-byte 6) (unsigned-byte 8))
(define-binop logeqv 1 3 eqv (unsigned-byte 6) (unsigned-byte 8) nil t)

;;; special cases for LOGAND where we can use a mask operation
(define-vop (fast-logand-c-mask/unsigned=>unsigned fast-unsigned-c-binop)
  (:translate logand)
  (:arg-types unsigned-num
              (:constant (or (integer #xffffffff #xffffffff)
                             (integer #xffffffff00000000 #xffffffff00000000))))
  (:generator 1
    (ecase y
      (#xffffffff (inst mskll x 4 r))
      (#xffffffff00000000 (inst mskll x 0 r)))))

;;;; shifting

(define-vop (fast-ash/unsigned=>unsigned)
  (:note "inline ASH")
  (:args (number :scs (unsigned-reg) :to :save)
         (amount :scs (signed-reg)))
  (:arg-types unsigned-num signed-num)
  (:results (result :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:translate ash)
  (:policy :fast-safe)
  (:temporary (:sc non-descriptor-reg) ndesc)
  (:temporary (:sc non-descriptor-reg) temp)
  (:generator 3
    (inst bge amount positive)
    (inst subq zero-tn amount ndesc)
    (inst cmplt ndesc 64 temp)
    (inst srl number ndesc result)
    ;; FIXME: this looks like a candidate for a conditional move --
    ;; CSR, 2003-09-10
    (inst bne temp done)
    (move zero-tn result)
    (inst br zero-tn done)

    POSITIVE
    (inst sll number amount result)

    DONE))

(define-vop (fast-ash/signed=>signed)
  (:note "inline ASH")
  (:args (number :scs (signed-reg) :to :save)
         (amount :scs (signed-reg)))
  (:arg-types signed-num signed-num)
  (:results (result :scs (signed-reg)))
  (:result-types signed-num)
  (:translate ash)
  (:policy :fast-safe)
  (:temporary (:sc non-descriptor-reg) ndesc)
  (:temporary (:sc non-descriptor-reg) temp)
  (:generator 3
    (inst bge amount positive)
    (inst subq zero-tn amount ndesc)
    (inst cmplt ndesc 63 temp)
    (inst sra number ndesc result)
    (inst bne temp done)
    (inst sra number 63 result)
    (inst br zero-tn done)

    POSITIVE
    (inst sll number amount result)

    DONE))

(define-vop (fast-ash-c/signed=>signed)
  (:policy :fast-safe)
  (:translate ash)
  (:note nil)
  (:args (number :scs (signed-reg)))
  (:info count)
  (:arg-types signed-num (:constant integer))
  (:results (result :scs (signed-reg)))
  (:result-types signed-num)
  (:generator 1
    (cond
      ((< count 0) (inst sra number (min 63 (- count)) result))
      ((> count 0) (inst sll number (min 63 count) result))
      (t (bug "identity ASH not transformed away")))))

(define-vop (fast-ash-c/unsigned=>unsigned)
  (:policy :fast-safe)
  (:translate ash)
  (:note nil)
  (:args (number :scs (unsigned-reg)))
  (:info count)
  (:arg-types unsigned-num (:constant integer))
  (:results (result :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:generator 1
    (cond
      ((< count -63) (move zero-tn result))
      ((< count 0) (inst sra number (- count) result))
      ((> count 0) (inst sll number (min 63 count) result))
      (t (bug "identity ASH not transformed away")))))

(macrolet ((def (name sc-type type result-type cost)
             `(define-vop (,name)
                (:note "inline ASH")
                (:translate ash)
                (:args (number :scs (,sc-type))
                       (amount :scs (signed-reg unsigned-reg immediate)))
                (:arg-types ,type positive-fixnum)
                (:results (result :scs (,result-type)))
                (:result-types ,type)
                (:policy :fast-safe)
                (:generator ,cost
                   (sc-case amount
                     ((signed-reg unsigned-reg)
                      (inst sll number amount result))
                     (immediate
                      (let ((amount (tn-value amount)))
                        (aver (> amount 0))
                        (inst sll number amount result))))))))
  (def fast-ash-left/fixnum=>fixnum any-reg tagged-num any-reg 2)
  (def fast-ash-left/signed=>signed signed-reg signed-num signed-reg 3)
  (def fast-ash-left/unsigned=>unsigned unsigned-reg unsigned-num unsigned-reg 3))

(define-vop (signed-byte-64-len)
  (:translate integer-length)
  (:note "inline (signed-byte 64) integer-length")
  (:policy :fast-safe)
  (:args (arg :scs (signed-reg) :to (:argument 1)))
  (:arg-types signed-num)
  (:results (res :scs (any-reg)))
  (:result-types positive-fixnum)
  (:temporary (:scs (non-descriptor-reg) :from (:argument 0)) shift)
  (:generator 30
    (inst not arg shift)
    (inst cmovge arg arg shift)
    (inst subq zero-tn (fixnumize 1) res)
    (inst sll shift 1 shift)
    LOOP
    (inst addq res (fixnumize 1) res)
    (inst srl shift 1 shift)
    (inst bne shift loop)))

(define-vop (unsigned-byte-64-count)
  (:translate logcount)
  (:note "inline (unsigned-byte 64) logcount")
  (:policy :fast-safe)
  (:args (arg :scs (unsigned-reg)))
  (:arg-types unsigned-num)
  (:results (res :scs (unsigned-reg)))
  (:result-types positive-fixnum)
  (:guard (member :cix *backend-subfeatures*))
  (:generator 1
    (inst ctpop zero-tn arg res)))

(define-vop (unsigned-byte-64-count)
  (:translate logcount)
  (:note "inline (unsigned-byte 64) logcount")
  (:policy :fast-safe)
  (:args (arg :scs (unsigned-reg) :target num))
  (:arg-types unsigned-num)
  (:results (res :scs (unsigned-reg)))
  (:result-types positive-fixnum)
  (:temporary (:scs (non-descriptor-reg) :from (:argument 0) :to (:result 0)
                    :target res) num)
  (:temporary (:scs (non-descriptor-reg)) mask temp)
  (:generator 60
    ;; FIXME: now this looks expensive, what with these 64bit loads.
    ;; Maybe a loop and count would be faster?  -- CSR, 2003-09-10
    (inst li #x5555555555555555 mask)
    (inst srl arg 1 temp)
    (inst and arg mask num)
    (inst and temp mask temp)
    (inst addq num temp num)
    (inst li #x3333333333333333 mask)
    (inst srl num 2 temp)
    (inst and num mask num)
    (inst and temp mask temp)
    (inst addq num temp num)
    (inst li #x0f0f0f0f0f0f0f0f mask)
    (inst srl num 4 temp)
    (inst and num mask num)
    (inst and temp mask temp)
    (inst addq num temp num)
    (inst li #x00ff00ff00ff00ff mask)
    (inst srl num 8 temp)
    (inst and num mask num)
    (inst and temp mask temp)
    (inst addq num temp num)
    (inst li #x0000ffff0000ffff mask)
    (inst srl num 16 temp)
    (inst and num mask num)
    (inst and temp mask temp)
    (inst addq num temp num)
    (inst li #x00000000ffffffff mask)
    (inst srl num 32 temp)
    (inst and num mask num)
    (inst and temp mask temp)
    (inst addq num temp res)))

;;;; multiplying

(define-vop (fast-*/fixnum=>fixnum fast-fixnum-binop)
  (:temporary (:scs (non-descriptor-reg)) temp)
  (:translate *)
  (:generator 4
    (inst sra y n-fixnum-tag-bits temp)
    (inst mulq x temp r)))

(define-vop (fast-*/signed=>signed fast-signed-binop)
  (:translate *)
  (:generator 3
    (inst mulq x y r)))

(define-vop (fast-*/unsigned=>unsigned fast-unsigned-binop)
  (:translate *)
  (:generator 3
    (inst mulq x y r)))

;;;; Modular functions:
(define-modular-fun lognot-mod64 (x) lognot :untagged nil 64)
(define-vop (lognot-mod64/unsigned=>unsigned)
  (:translate lognot-mod64)
  (:args (x :scs (unsigned-reg)))
  (:arg-types unsigned-num)
  (:results (res :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:policy :fast-safe)
  (:generator 1
    (inst not x res)))

(define-vop (fast-ash-left-mod64-c/unsigned=>unsigned
             fast-ash-c/unsigned=>unsigned)
  (:translate ash-left-mod64))
(define-vop (fast-ash-left-mod64/unsigned=>unsigned
             fast-ash-left/unsigned=>unsigned))
(deftransform ash-left-mod64 ((integer count)
                              ((unsigned-byte 64) (unsigned-byte 6)))
  (when (sb!c::constant-lvar-p count)
    (sb!c::give-up-ir1-transform))
  '(%primitive fast-ash-left-mod64/unsigned=>unsigned integer count))

(macrolet
    ((define-modular-backend (fun &optional constantp)
       (let ((mfun-name (symbolicate fun '-mod64))
             (modvop (symbolicate 'fast- fun '-mod64/unsigned=>unsigned))
             (modcvop (symbolicate 'fast- fun '-mod64-c/unsigned=>unsigned))
             (vop (symbolicate 'fast- fun '/unsigned=>unsigned))
             (cvop (symbolicate 'fast- fun '-c/unsigned=>unsigned)))
         `(progn
            (define-modular-fun ,mfun-name (x y) ,fun :untagged nil 64)
            (define-vop (,modvop ,vop)
              (:translate ,mfun-name))
            ,@(when constantp
                `((define-vop (,modcvop ,cvop)
                    (:translate ,mfun-name))))))))
  (define-modular-backend + t)
  (define-modular-backend - t)
  (define-modular-backend logeqv t)
  (define-modular-backend logandc1)
  (define-modular-backend logandc2 t)
  (define-modular-backend logorc1)
  (define-modular-backend logorc2 t))

(define-source-transform lognand (x y)
  `(lognot (logand ,x ,y)))
(define-source-transform lognor (x y)
  `(lognot (logior ,x ,y)))