arith.lisp

开源跨平台Lisp编译器

    (inst b? (if not-p :ne :eq) target)))
;;;
(define-vop (generic-eql-c/fixnum fast-eql-c/fixnum)
  (:arg-types * (:constant (signed-byte 11)))
  (:variant-cost 6))


;;;; 32-bit logical operations

(define-vop (merge-bits)
  (:translate merge-bits)
  (:args (shift :scs (signed-reg unsigned-reg))
         (prev :scs (unsigned-reg))
         (next :scs (unsigned-reg)))
  (:arg-types tagged-num unsigned-num unsigned-num)
  (:temporary (:scs (unsigned-reg) :to (:result 0)) temp)
  (:temporary (:scs (unsigned-reg) :to (:result 0) :target result) res)
  (:results (result :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:policy :fast-safe)
  (:generator 4
    (let ((done (gen-label)))
      (inst cmpwi shift 0)
      (inst beq done)
      (inst srw res next shift)
      (inst sub temp zero-tn shift)
      (inst slw temp prev temp)
      (inst or res res temp)
      (emit-label done)
      (move result res))))

(define-vop (shift-towards-someplace)
  (:policy :fast-safe)
  (:args (num :scs (unsigned-reg))
         (amount :scs (signed-reg)))
  (:arg-types unsigned-num tagged-num)
  (:results (r :scs (unsigned-reg)))
  (:result-types unsigned-num))

(define-vop (shift-towards-start shift-towards-someplace)
  (:translate shift-towards-start)
  (:note "shift-towards-start")
  (:generator 1
    (inst rlwinm amount amount 0 27 31)
    (inst slw r num amount)))

(define-vop (shift-towards-end shift-towards-someplace)
  (:translate shift-towards-end)
  (:note "shift-towards-end")
  (:generator 1
    (inst rlwinm amount amount 0 27 31)
    (inst srw r num amount)))

;;;; Bignum stuff.

(define-vop (bignum-length get-header-data)
  (:translate sb!bignum:%bignum-length)
  (:policy :fast-safe))

(define-vop (bignum-set-length set-header-data)
  (:translate sb!bignum:%bignum-set-length)
  (:policy :fast-safe))

(define-vop (bignum-ref word-index-ref)
  (:variant bignum-digits-offset other-pointer-lowtag)
  (:translate sb!bignum:%bignum-ref)
  (:results (value :scs (unsigned-reg)))
  (:result-types unsigned-num))

(define-vop (bignum-set word-index-set)
  (:variant bignum-digits-offset other-pointer-lowtag)
  (:translate sb!bignum:%bignum-set)
  (:args (object :scs (descriptor-reg))
         (index :scs (any-reg immediate zero))
         (value :scs (unsigned-reg)))
  (:arg-types t positive-fixnum unsigned-num)
  (:results (result :scs (unsigned-reg)))
  (:result-types unsigned-num))

(define-vop (digit-0-or-plus)
  (:translate sb!bignum:%digit-0-or-plusp)
  (:policy :fast-safe)
  (:args (digit :scs (unsigned-reg)))
  (:arg-types unsigned-num)
  (:results (result :scs (descriptor-reg)))
  (:generator 3
    (let ((done (gen-label)))
      (inst cmpwi digit 0)
      (move result null-tn)
      (inst blt done)
      (load-symbol result t)
      (emit-label done))))

(define-vop (add-w/carry)
  (:translate sb!bignum:%add-with-carry)
  (:policy :fast-safe)
  (:args (a :scs (unsigned-reg))
         (b :scs (unsigned-reg))
         (c :scs (any-reg)))
  (:arg-types unsigned-num unsigned-num positive-fixnum)
  (:temporary (:scs (unsigned-reg)) temp)
  (:results (result :scs (unsigned-reg))
            (carry :scs (unsigned-reg)))
  (:result-types unsigned-num positive-fixnum)
  (:generator 3
    (inst addic temp c -1)
    (inst adde result a b)
    (inst addze carry zero-tn)))

(define-vop (sub-w/borrow)
  (:translate sb!bignum:%subtract-with-borrow)
  (:policy :fast-safe)
  (:args (a :scs (unsigned-reg))
         (b :scs (unsigned-reg))
         (c :scs (any-reg)))
  (:arg-types unsigned-num unsigned-num positive-fixnum)
  (:temporary (:scs (unsigned-reg)) temp)
  (:results (result :scs (unsigned-reg))
            (borrow :scs (unsigned-reg)))
  (:result-types unsigned-num positive-fixnum)
  (:generator 4
    (inst addic temp c -1)
    (inst sube result a b)
    (inst addze borrow zero-tn)))

(define-vop (bignum-mult-and-add-3-arg)
  (:translate sb!bignum:%multiply-and-add)
  (:policy :fast-safe)
  (:args (x :scs (unsigned-reg))
         (y :scs (unsigned-reg))
         (carry-in :scs (unsigned-reg) :to (:eval 1)))
  (:arg-types unsigned-num unsigned-num unsigned-num)
  (:temporary (:scs (unsigned-reg) :to (:result 0) :target hi) hi-temp)
  (:temporary (:scs (unsigned-reg) :from (:eval 0) :to (:result 1)
                    :target lo) lo-temp)
  (:results (hi :scs (unsigned-reg))
            (lo :scs (unsigned-reg)))
  (:result-types unsigned-num unsigned-num)
  (:generator 40
    (inst mulhwu hi-temp x y)
    (inst mullw lo-temp x y)
    (inst addc lo lo-temp carry-in)
    (inst addze hi hi-temp)))

(define-vop (bignum-mult-and-add-4-arg)
  (:translate sb!bignum:%multiply-and-add)
  (:policy :fast-safe)
  (:args (x :scs (unsigned-reg))
         (y :scs (unsigned-reg))
         (prev :scs (unsigned-reg) :to (:eval 1))
         (carry-in :scs (unsigned-reg) :to (:eval 1)))
  (:arg-types unsigned-num unsigned-num unsigned-num unsigned-num)
  (:temporary (:scs (unsigned-reg) :to (:result 0) :target hi) hi-temp)
  (:temporary (:scs (unsigned-reg) :from (:eval 0) :to (:result 1)
                    :target lo) lo-temp)
  (:results (hi :scs (unsigned-reg))
            (lo :scs (unsigned-reg)))
  (:result-types unsigned-num unsigned-num)
  (:generator 40
    (inst mulhwu hi-temp x y)
    (inst mullw lo-temp x y)
    (inst addc lo-temp lo-temp carry-in)
    (inst addze hi-temp hi-temp)
    (inst addc lo lo-temp prev)
    (inst addze hi hi-temp)))

(define-vop (bignum-mult)
  (:translate sb!bignum:%multiply)
  (:policy :fast-safe)
  (:args (x :scs (unsigned-reg) :to (:eval 1))
         (y :scs (unsigned-reg) :to (:eval 1)))
  (:arg-types unsigned-num unsigned-num)
  (:results (hi :scs (unsigned-reg) :from (:eval 1))
            (lo :scs (unsigned-reg) :from (:eval 0)))
  (:result-types unsigned-num unsigned-num)
  (:generator 40
    (inst mullw lo x y)
    (inst mulhwu hi x y)))

(define-vop (bignum-lognot lognot-mod32/unsigned=>unsigned)
  (:translate sb!bignum:%lognot))

(define-vop (fixnum-to-digit)
  (:translate sb!bignum:%fixnum-to-digit)
  (:policy :fast-safe)
  (:args (fixnum :scs (any-reg)))
  (:arg-types tagged-num)
  (:results (digit :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:generator 1
    (inst srawi digit fixnum 2)))


(define-vop (bignum-floor)
  (:translate sb!bignum:%floor)
  (:policy :fast-safe)
  (:args (num-high :scs (unsigned-reg) :target rem)
         (num-low :scs (unsigned-reg) :target rem-low)
         (denom :scs (unsigned-reg) :to (:eval 1)))
  (:arg-types unsigned-num unsigned-num unsigned-num)
  (:temporary (:scs (unsigned-reg) :from (:argument 1)) rem-low)
  (:temporary (:scs (unsigned-reg) :from (:eval 0)) temp)
  (:results (quo :scs (unsigned-reg) :from (:eval 0))
            (rem :scs (unsigned-reg) :from (:argument 0)))
  (:result-types unsigned-num unsigned-num)
  (:generator 325 ; number of inst assuming targeting works.
    (move rem num-high)
    (move rem-low num-low)
    (flet ((maybe-subtract (&optional (guess temp))
             (inst subi temp guess 1)
             (inst and temp temp denom)
             (inst sub rem rem temp))
           (sltu (res x y)
             (inst subfc res y x)
             (inst subfe res res res)
             (inst neg res res)))
      (sltu quo rem denom)
      (maybe-subtract quo)
      (dotimes (i 32)
        (inst slwi rem rem 1)
        (inst srwi temp rem-low 31)
        (inst or rem rem temp)
        (inst slwi rem-low rem-low 1)
        (sltu temp rem denom)
        (inst slwi quo quo 1)
        (inst or quo quo temp)
        (maybe-subtract)))
    (inst not quo quo)))

#|

(define-vop (bignum-floor)
  (:translate sb!bignum:%floor)
  (:policy :fast-safe)
  (:args (div-high :scs (unsigned-reg) :target rem)
         (div-low :scs (unsigned-reg) :target quo)
         (divisor :scs (unsigned-reg)))
  (:arg-types unsigned-num unsigned-num unsigned-num)
  (:results (quo :scs (unsigned-reg) :from (:argument 1))
            (rem :scs (unsigned-reg) :from (:argument 0)))
  (:result-types unsigned-num unsigned-num)
  (:generator 300
    (inst mtmq div-low)
    (inst div quo div-high divisor)
    (inst mfmq rem)))
|#

(define-vop (signify-digit)
  (:translate sb!bignum:%fixnum-digit-with-correct-sign)
  (:policy :fast-safe)
  (:args (digit :scs (unsigned-reg) :target res))
  (:arg-types unsigned-num)
  (:results (res :scs (any-reg signed-reg)))
  (:result-types signed-num)
  (:generator 1
    (sc-case res
      (any-reg
       (inst slwi res digit 2))
      (signed-reg
       (move res digit)))))


(define-vop (digit-ashr)
  (:translate sb!bignum:%ashr)
  (:policy :fast-safe)
  (:args (digit :scs (unsigned-reg))
         (count :scs (unsigned-reg)))
  (:arg-types unsigned-num positive-fixnum)
  (:results (result :scs (unsigned-reg)))
  (:result-types unsigned-num)
  (:generator 1
    (inst sraw result digit count)))

(define-vop (digit-lshr digit-ashr)
  (:translate sb!bignum:%digit-logical-shift-right)
  (:generator 1
    (inst srw result digit count)))

(define-vop (digit-ashl digit-ashr)
  (:translate sb!bignum:%ashl)
  (:generator 1
    (inst slw result digit count)))


;;;; Static funs.

(define-static-fun two-arg-gcd (x y) :translate gcd)
(define-static-fun two-arg-lcm (x y) :translate lcm)

(define-static-fun two-arg-+ (x y) :translate +)
(define-static-fun two-arg-- (x y) :translate -)
(define-static-fun two-arg-* (x y) :translate *)
(define-static-fun two-arg-/ (x y) :translate /)

(define-static-fun two-arg-< (x y) :translate <)
(define-static-fun two-arg-<= (x y) :translate <=)
(define-static-fun two-arg-> (x y) :translate >)
(define-static-fun two-arg->= (x y) :translate >=)
(define-static-fun two-arg-= (x y) :translate =)
(define-static-fun two-arg-/= (x y) :translate /=)

(define-static-fun %negate (x) :translate %negate)

(define-static-fun two-arg-and (x y) :translate logand)
(define-static-fun two-arg-ior (x y) :translate logior)
(define-static-fun two-arg-xor (x y) :translate logxor)
(define-static-fun two-arg-eqv (x y) :translate logeqv)

(in-package "SB!C")

(deftransform * ((x y)
                 ((unsigned-byte 32) (constant-arg (unsigned-byte 32)))
                 (unsigned-byte 32))
  "recode as shifts and adds"
  (let ((y (lvar-value y)))
    (multiple-value-bind (result adds shifts)
        (ub32-strength-reduce-constant-multiply 'x y)
      (cond
       ((typep y '(signed-byte 16))
        ;; a mulli instruction has a latency of 5.
        (when (> (+ adds shifts) 4)
          (give-up-ir1-transform)))
       (t
        ;; a mullw instruction also has a latency of 5, plus two
        ;; instructions (in general) to load the immediate into a
        ;; register.
        (when (> (+ adds shifts) 6)
          (give-up-ir1-transform))))
      (or result 0))))