arith.lisp

开源跨平台Lisp编译器

  (:arg-types signed-num)
  (:results (res :scs (any-reg)))
  (:result-types positive-fixnum)
  (:temporary (:scs (non-descriptor-reg) :from (:argument 0)) shift)
  (:generator 30
    (let ((loop (gen-label))
          (test (gen-label)))
      (move shift arg)
      (inst bgez shift test)
      (move res zero-tn t)
      (inst b test)
      (inst nor shift shift)

      (emit-label loop)
      (inst add res (fixnumize 1))

      (emit-label test)
      (inst bne shift loop)
      (inst srl shift 1))))

(define-vop (unsigned-byte-32-count)
  (:translate logcount)
  (:note "inline (unsigned-byte 32) 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 30
    (inst li mask #x55555555)
    (inst srl temp arg 1)
    (inst and num arg mask)
    (inst and temp mask)
    (inst addu num temp)
    (inst li mask #x33333333)
    (inst srl temp num 2)
    (inst and num mask)
    (inst and temp mask)
    (inst addu num temp)
    (inst li mask #x0f0f0f0f)
    (inst srl temp num 4)
    (inst and num mask)
    (inst and temp mask)
    (inst addu num temp)
    (inst li mask #x00ff00ff)
    (inst srl temp num 8)
    (inst and num mask)
    (inst and temp mask)
    (inst addu num temp)
    (inst li mask #x0000ffff)
    (inst srl temp num 16)
    (inst and num mask)
    (inst and temp mask)
    (inst addu res num temp)))


;;; Multiply and Divide.

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

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

(define-vop (fast-*/unsigned=>unsigned fast-unsigned-binop)
  (:translate *)
  (:generator 3
    (inst multu x y)
    (inst mflo r)))



(define-vop (fast-truncate/fixnum fast-fixnum-binop)
  (:translate truncate)
  (:results (q :scs (any-reg))
            (r :scs (any-reg)))
  (:result-types tagged-num tagged-num)
  (:temporary (:scs (non-descriptor-reg) :to :eval) temp)
  (:vop-var vop)
  (:save-p :compute-only)
  (:generator 11
    (let ((zero (generate-error-code vop division-by-zero-error x y)))
      (inst beq y zero))
    (inst nop)
    (inst div x y)
    (inst mflo temp)
    (inst sll q temp n-fixnum-tag-bits)
    (inst mfhi r)))

(define-vop (fast-truncate/unsigned fast-unsigned-binop)
  (:translate truncate)
  (:results (q :scs (unsigned-reg))
            (r :scs (unsigned-reg)))
  (:result-types unsigned-num unsigned-num)
  (:vop-var vop)
  (:save-p :compute-only)
  (:generator 12
    (let ((zero (generate-error-code vop division-by-zero-error x y)))
      (inst beq y zero))
    (inst nop)
    (inst divu x y)
    (inst mflo q)
    (inst mfhi r)))

(define-vop (fast-truncate/signed fast-signed-binop)
  (:translate truncate)
  (:results (q :scs (signed-reg))
            (r :scs (signed-reg)))
  (:result-types signed-num signed-num)
  (:vop-var vop)
  (:save-p :compute-only)
  (:generator 12
    (let ((zero (generate-error-code vop division-by-zero-error x y)))
      (inst beq y zero))
    (inst nop)
    (inst div x y)
    (inst mflo q)
    (inst mfhi r)))



;;;; Binary conditional VOPs:

(define-vop (fast-conditional)
  (:conditional)
  (:info target not-p)
  (:effects)
  (:affected)
  (:temporary (:scs (non-descriptor-reg)) temp)
  (:policy :fast-safe))

(define-vop (fast-conditional/fixnum fast-conditional)
  (:args (x :scs (any-reg))
         (y :scs (any-reg)))
  (:arg-types tagged-num tagged-num)
  (:note "inline fixnum comparison"))

(define-vop (fast-conditional-c/fixnum fast-conditional/fixnum)
  (:args (x :scs (any-reg)))
  (:arg-types tagged-num (:constant (signed-byte-with-a-bite-out 14 4)))
  (:info target not-p y))

(define-vop (fast-conditional/signed fast-conditional)
  (:args (x :scs (signed-reg))
         (y :scs (signed-reg)))
  (:arg-types signed-num signed-num)
  (:note "inline (signed-byte 32) comparison"))

(define-vop (fast-conditional-c/signed fast-conditional/signed)
  (:args (x :scs (signed-reg)))
  (:arg-types signed-num (:constant (signed-byte-with-a-bite-out 16 1)))
  (:info target not-p y))

(define-vop (fast-conditional/unsigned fast-conditional)
  (:args (x :scs (unsigned-reg))
         (y :scs (unsigned-reg)))
  (:arg-types unsigned-num unsigned-num)
  (:note "inline (unsigned-byte 32) comparison"))

(define-vop (fast-conditional-c/unsigned fast-conditional/unsigned)
  (:args (x :scs (unsigned-reg)))
  (:arg-types unsigned-num (:constant (and (signed-byte-with-a-bite-out 16 1)
                                           unsigned-byte)))
  (:info target not-p y))


(defmacro define-conditional-vop (translate &rest generator)
  `(progn
     ,@(mapcar #'(lambda (suffix cost signed)
                   (unless (and (member suffix '(/fixnum -c/fixnum))
                                (eq translate 'eql))
                     `(define-vop (,(intern (format nil "~:@(FAST-IF-~A~A~)"
                                                    translate suffix))
                                   ,(intern
                                     (format nil "~:@(FAST-CONDITIONAL~A~)"
                                             suffix)))
                        (:translate ,translate)
                        (:generator ,cost
                          (let* ((signed ,signed)
                                 (-c/fixnum ,(eq suffix '-c/fixnum))
                                 (y (if -c/fixnum (fixnumize y) y)))
                            (declare (ignorable signed -c/fixnum y))
                            ,@generator)))))
               '(/fixnum -c/fixnum /signed -c/signed /unsigned -c/unsigned)
               '(3 2 5 4 5 4)
               '(t t t t nil nil))))

(define-conditional-vop <
  (cond ((and signed (eql y 0))
         (if not-p
             (inst bgez x target)
             (inst bltz x target)))
        (t
         (if signed
             (inst slt temp x y)
             (inst sltu temp x y))
         (if not-p
             (inst beq temp target)
             (inst bne temp target))))
  (inst nop))

(define-conditional-vop >
  (cond ((and signed (eql y 0))
         (if not-p
             (inst blez x target)
             (inst bgtz x target)))
        ((integerp y)
         (let ((y (+ y (if -c/fixnum (fixnumize 1) 1))))
           (if signed
               (inst slt temp x y)
               (inst sltu temp x y))
           (if not-p
               (inst bne temp target)
               (inst beq temp target))))
        (t
         (if signed
             (inst slt temp y x)
             (inst sltu temp y x))
         (if not-p
             (inst beq temp target)
             (inst bne temp target))))
  (inst nop))

;;; EQL/FIXNUM is funny because the first arg can be of any type, not just a
;;; known fixnum.

(define-conditional-vop eql
  (declare (ignore signed))
  (when (integerp y)
    (inst li temp y)
    (setf y temp))
  (if not-p
      (inst bne x y target)
      (inst beq x y target))
  (inst nop))

;;; These versions specify a fixnum restriction on their first arg.  We have
;;; also generic-eql/fixnum VOPs which are the same, but have no restriction on
;;; the first arg and a higher cost.  The reason for doing this is to prevent
;;; fixnum specific operations from being used on word integers, spuriously
;;; consing the argument.
;;;
(define-vop (fast-eql/fixnum fast-conditional)
  (:args (x :scs (any-reg))
         (y :scs (any-reg)))
  (:arg-types tagged-num tagged-num)
  (:note "inline fixnum comparison")
  (:translate eql)
  (:ignore temp)
  (:generator 3
    (if not-p
        (inst bne x y target)
        (inst beq x y target))
    (inst nop)))
;;;
(define-vop (generic-eql/fixnum fast-eql/fixnum)
  (:args (x :scs (any-reg descriptor-reg))
         (y :scs (any-reg)))
  (:arg-types * tagged-num)
  (:variant-cost 7))

(define-vop (fast-eql-c/fixnum fast-conditional/fixnum)
  (:args (x :scs (any-reg)))
  (:arg-types tagged-num (:constant (signed-byte 14)))
  (:info target not-p y)
  (:translate eql)
  (:generator 2
    (let ((y (cond ((eql y 0) zero-tn)
                   (t
                    (inst li temp (fixnumize y))
                    temp))))
      (if not-p
          (inst bne x y target)
          (inst beq x y target))
      (inst nop))))
;;;
(define-vop (generic-eql-c/fixnum fast-eql-c/fixnum)
  (:args (x :scs (any-reg descriptor-reg)))
  (:arg-types * (:constant (signed-byte 14)))
  (: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 beq shift done)
      (inst srl res next shift)
      (inst subu temp zero-tn shift)
      (inst sll 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)