[Emacs-diffs] Changes to emacs/lisp/emacs-lisp/float.el

[Miles Bader]

Index: emacs/lisp/emacs-lisp/float.el
diff -c emacs/lisp/emacs-lisp/float.el:1.13 emacs/lisp/emacs-lisp/float.el:1.14
*** emacs/lisp/emacs-lisp/float.el:1.13 Sun Jul 15 12:15:34 2001
--- emacs/lisp/emacs-lisp/float.el      Fri Sep  6 03:13:53 2002
***************
*** 39,52 ****
  ;; function string-to-float converts from string to floating point
  ;; function fint converts a floating point to integer (with truncation)
  ;; function float-to-string converts from floating point to string
! ;;                   
  ;; Caveats:
! ;; -  Exponents outside of the range of +/-100 or so will cause certain 
  ;;    functions (especially conversion routines) to take forever.
  ;; -  Very little checking is done for fixed point overflow/underflow.
  ;; -  No checking is done for over/underflow of the exponent
  ;;    (hardly necessary when exponent can be 2**23).
! ;; 
  ;;
  ;; Bill Rosenblatt
  ;; June 20, 1986
--- 39,52 ----
  ;; function string-to-float converts from string to floating point
  ;; function fint converts a floating point to integer (with truncation)
  ;; function float-to-string converts from floating point to string
! ;;
  ;; Caveats:
! ;; -  Exponents outside of the range of +/-100 or so will cause certain
  ;;    functions (especially conversion routines) to take forever.
  ;; -  Very little checking is done for fixed point overflow/underflow.
  ;; -  No checking is done for over/underflow of the exponent
  ;;    (hardly necessary when exponent can be 2**23).
! ;;
  ;;
  ;; Bill Rosenblatt
  ;; June 20, 1986
***************
*** 131,137 ****
          (setq fnum (fashl fnum)))
        (setq fnum _f0)))                       ; "standard 0"
    fnum)
!       
  (defun abs (n)                                ; integer absolute value
    (if (>= n 0) n (- n)))
  
--- 131,137 ----
          (setq fnum (fashl fnum)))
        (setq fnum _f0)))                       ; "standard 0"
    fnum)
! 
  (defun abs (n)                                ; integer absolute value
    (if (>= n 0) n (- n)))
  
***************
*** 204,210 ****
    (if (zerop (car a2))                        ; if divide by 0
        (signal 'arith-error (list "attempt to divide by zero" a1 a2))
      (let ((bits (1- maxbit))
!         (quotient 0) 
          (dividend (car (fabs a1)))
          (divisor (car (fabs a2)))
          (sign (not (same-sign a1 a2))))
--- 204,210 ----
    (if (zerop (car a2))                        ; if divide by 0
        (signal 'arith-error (list "attempt to divide by zero" a1 a2))
      (let ((bits (1- maxbit))
!         (quotient 0)
          (dividend (car (fabs a1)))
          (divisor (car (fabs a2)))
          (sign (not (same-sign a1 a2))))
***************
*** 218,228 ****
        (normalize
         (cons (if sign (- quotient) quotient)
             (- (cdr (fabs a1)) (cdr (fabs a2)) (1- maxbit)))))))
!   
  (defun f% (a1 a2)
    "Returns the remainder of first floating point number divided by second."
    (f- a1 (f* (ftrunc (f/ a1 a2)) a2)))
!         
  
  ;; Comparison functions
  (defun f= (a1 a2)
--- 218,228 ----
        (normalize
         (cons (if sign (- quotient) quotient)
             (- (cdr (fabs a1)) (cdr (fabs a2)) (1- maxbit)))))))
! 
  (defun f% (a1 a2)
    "Returns the remainder of first floating point number divided by second."
    (f- a1 (f* (ftrunc (f/ a1 a2)) a2)))
! 
  
  ;; Comparison functions
  (defun f= (a1 a2)
***************
*** 232,238 ****
  (defun f> (a1 a2)
    "Returns t if first floating point number is greater than second,
  nil otherwise."
!   (cond ((and (natnump (car a1)) (< (car a2) 0)) 
         t)                             ; a1 nonnegative, a2 negative
        ((and (> (car a1) 0) (<= (car a2) 0))
         t)                             ; a1 positive, a2 nonpositive
--- 232,238 ----
  (defun f> (a1 a2)
    "Returns t if first floating point number is greater than second,
  nil otherwise."
!   (cond ((and (natnump (car a1)) (< (car a2) 0))
         t)                             ; a1 nonnegative, a2 negative
        ((and (> (car a1) 0) (<= (car a2) 0))
         t)                             ; a1 positive, a2 nonpositive
***************
*** 244,250 ****
         (> (car a1) (car a2)))))       ; same exponents.
  
  (defun f>= (a1 a2)
!   "Returns t if first floating point number is greater than or equal to 
  second, nil otherwise."
    (or (f> a1 a2) (f= a1 a2)))
  
--- 244,250 ----
         (> (car a1) (car a2)))))       ; same exponents.
  
  (defun f>= (a1 a2)
!   "Returns t if first floating point number is greater than or equal to
  second, nil otherwise."
    (or (f> a1 a2) (f= a1 a2)))
  
***************
*** 270,276 ****
  (defun fmax (a1 a2)
    "Returns the maximum of two floating point numbers."
    (if (f> a1 a2) a1 a2))
!       
  (defun fzerop (fnum)
    "Returns t if the floating point number is zero, nil otherwise."
    (= (car fnum) 0))
--- 270,276 ----
  (defun fmax (a1 a2)
    "Returns the maximum of two floating point numbers."
    (if (f> a1 a2) a1 a2))
! 
  (defun fzerop (fnum)
    "Returns t if the floating point number is zero, nil otherwise."
    (= (car fnum) 0))
***************
*** 290,296 ****
        (str "0x")
        (hex-chars "0123456789ABCDEF"))
      (while (<= shiftval 0)
!       (setq str (concat str (char-to-string 
                        (aref hex-chars
                              (logand (lsh int shiftval) 15))))
            shiftval (+ shiftval 4)))
--- 290,296 ----
        (str "0x")
        (hex-chars "0123456789ABCDEF"))
      (while (<= shiftval 0)
!       (setq str (concat str (char-to-string
                        (aref hex-chars
                              (logand (lsh int shiftval) 15))))
            shiftval (+ shiftval 4)))
***************
*** 304,317 ****
         '(0 . 1))
        (t                              ; otherwise mask out fractional bits
         (let ((mant (car fnum)) (exp (cdr fnum)))
!          (normalize 
            (cons (if (natnump mant)    ; if negative, use absolute value
                      (ash (ash mant exp) (- exp))
                    (- (ash (ash (- mant) exp) (- exp))))
                  exp))))))
  
  (defun fint (fnum)                    ; truncate and convert to integer
!   "Convert the floating point number to integer, with truncation, 
  like a C cast operator."
    (let* ((tf (ftrunc fnum)) (tint (car tf)) (texp (cdr tf)))
      (cond ((>= texp mantissa-bits)    ; too high, return "maxint"
--- 304,317 ----
         '(0 . 1))
        (t                              ; otherwise mask out fractional bits
         (let ((mant (car fnum)) (exp (cdr fnum)))
!          (normalize
            (cons (if (natnump mant)    ; if negative, use absolute value
                      (ash (ash mant exp) (- exp))
                    (- (ash (ash (- mant) exp) (- exp))))
                  exp))))))
  
  (defun fint (fnum)                    ; truncate and convert to integer
!   "Convert the floating point number to integer, with truncation,
  like a C cast operator."
    (let* ((tf (ftrunc fnum)) (tint (car tf)) (texp (cdr tf)))
      (cond ((>= texp mantissa-bits)    ; too high, return "maxint"
***************
*** 325,331 ****
    "Convert the floating point number to a decimal string.
  Optional second argument non-nil means use scientific notation."
    (let* ((value (fabs fnum)) (sign (< (car fnum) 0))
!        (power 0) (result 0) (str "") 
         (temp 0) (pow10 _f1))
  
      (if (f= fnum _f0)
--- 325,331 ----
    "Convert the floating point number to a decimal string.
  Optional second argument non-nil means use scientific notation."
    (let* ((value (fabs fnum)) (sign (< (car fnum) 0))
!        (power 0) (result 0) (str "")
         (temp 0) (pow10 _f1))
  
      (if (f= fnum _f0)
***************
*** 386,398 ****
          (concat "-" str)
        str))))
  
!     
  ;; string to float conversion.
  ;; accepts scientific notation, but ignores anything after the first two
  ;; digits of the exponent.
  (defun string-to-float (str)
    "Convert the string to a floating point number.
! Accepts a decimal string in scientific notation,  with exponent preceded
  by either E or e.  Only the six most significant digits of the integer
  and fractional parts are used; only the first two digits of the exponent
  are used.  Negative signs preceding both the decimal number and the exponent
--- 386,398 ----
          (concat "-" str)
        str))))
  
! 
  ;; string to float conversion.
  ;; accepts scientific notation, but ignores anything after the first two
  ;; digits of the exponent.
  (defun string-to-float (str)
    "Convert the string to a floating point number.
! Accepts a decimal string in scientific notation, with exponent preceded
  by either E or e.  Only the six most significant digits of the integer
  and fractional parts are used; only the first two digits of the exponent
  are used.  Negative signs preceding both the decimal number and the exponent
***************
*** 415,421 ****
             (setq leading-0s (1+ leading-0s)))
           (setq power (- power leading-0s)
                 digit-string (substring digit-string leading-0s))
!          
           ; if more than 6 digits, round off
           (if (> (length digit-string) decimal-digits)
               (setq round-up (>= (aref digit-string decimal-digits) ?5)
--- 415,421 ----
             (setq leading-0s (1+ leading-0s)))
           (setq power (- power leading-0s)
                 digit-string (substring digit-string leading-0s))
! 
           ; if more than 6 digits, round off
           (if (> (length digit-string) decimal-digits)
               (setq round-up (>= (aref digit-string decimal-digits) ?5)
***************
*** 426,438 ****
           (f (* (+ (string-to-int digit-string)
                    (if round-up 1 0))
                 (if mant-sign -1 1))))
!          
         ; calculate the exponent (power of ten)
         (let* ((expt-subst (extract-match str 9))
                (expt-sign (equal (extract-match str 8) "-"))
                (expt 0) (chunks 0) (tens 0) (exponent _f1)
                (func 'f*))
!  
           (setq expt (+ (* (string-to-int
                             (substring expt-subst 0
                                        (min expt-digits (length expt-subst))))
--- 426,438 ----
           (f (* (+ (string-to-int digit-string)
                    (if round-up 1 0))
                 (if mant-sign -1 1))))
! 
         ; calculate the exponent (power of ten)
         (let* ((expt-subst (extract-match str 9))
                (expt-sign (equal (extract-match str 8) "-"))
                (expt 0) (chunks 0) (tens 0) (exponent _f1)
                (func 'f*))
! 
           (setq expt (+ (* (string-to-int
                             (substring expt-subst 0
                                        (min expt-digits (length expt-subst))))
***************
*** 445,456 ****
           (setq chunks (/ expt decimal-digits)
                 tens (% expt decimal-digits))
           ; divide or multiply by "chunks" of 10**6
!          (while (> chunks 0)  
             (setq exponent (funcall func exponent highest-power-of-10)
                   chunks (1- chunks)))
           ; divide or multiply by remaining power of ten
           (funcall func exponent (aref powers-of-10 tens)))))
!                 
      _f0))                             ; if invalid, return 0
  
  (provide 'float)
--- 445,456 ----
           (setq chunks (/ expt decimal-digits)
                 tens (% expt decimal-digits))
           ; divide or multiply by "chunks" of 10**6
!          (while (> chunks 0)
             (setq exponent (funcall func exponent highest-power-of-10)
                   chunks (1- chunks)))
           ; divide or multiply by remaining power of ten
           (funcall func exponent (aref powers-of-10 tens)))))
! 
      _f0))                             ; if invalid, return 0
  
  (provide 'float)