X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fnumbers.lisp;h=5522134a50c53af037cd063ab156b07ef2db6d6d;hb=224466fab9dc4e8b3faf13a121f827f198811bf6;hp=f3adc3bcae6d69661f5acbc65d70ac69d1b27d98;hpb=4b58efcd710097cf7cc9b1a1bed8b0e1bd6eb3b8;p=sbcl.git diff --git a/src/code/numbers.lisp b/src/code/numbers.lisp index f3adc3b..5522134 100644 --- a/src/code/numbers.lisp +++ b/src/code/numbers.lisp @@ -1004,8 +1004,9 @@ if INTEGER is negative." (etypecase integer (fixnum - (logcount (truly-the (integer 0 #.(max most-positive-fixnum - (lognot most-negative-fixnum))) + (logcount (truly-the (integer 0 + #.(max sb!xc:most-positive-fixnum + (lognot sb!xc:most-negative-fixnum))) (if (minusp (truly-the fixnum integer)) (lognot (truly-the fixnum integer)) integer)))) @@ -1020,7 +1021,12 @@ (defun logbitp (index integer) #!+sb-doc "Predicate returns T if bit index of integer is a 1." - (logbitp index integer)) + (number-dispatch ((index integer) (integer integer)) + ((fixnum fixnum) (if (> index #.(- sb!vm:n-word-bits sb!vm:n-lowtag-bits)) + (minusp integer) + (not (zerop (logand integer (ash 1 index)))))) + ((fixnum bignum) (bignum-logbitp index integer)) + ((bignum (foreach fixnum bignum)) (minusp integer)))) (defun ash (integer count) #!+sb-doc @@ -1259,13 +1265,20 @@ (defun two-arg-lcm (n m) (declare (integer n m)) - (let ((m (abs m)) - (n (abs n))) - (multiple-value-bind (max min) - (if (> m n) - (values m n) - (values n m)) - (* (truncate max (gcd n m)) min)))) + (if (or (zerop n) (zerop m)) + 0 + ;; KLUDGE: I'm going to assume that it was written this way + ;; originally for a reason. However, this is a somewhat + ;; complicated way of writing the algorithm in the CLHS page for + ;; LCM, and I don't know why. To be investigated. -- CSR, + ;; 2003-09-11 + (let ((m (abs m)) + (n (abs n))) + (multiple-value-bind (max min) + (if (> m n) + (values m n) + (values n m)) + (* (truncate max (gcd n m)) min))))) ;;; Do the GCD of two integer arguments. With fixnum arguments, we use the ;;; binary GCD algorithm from Knuth's seminumerical algorithms (slightly @@ -1345,16 +1358,13 @@ #. (collect ((forms)) (flet ((definition (name lambda-list width pattern) - ;; We rely on (SUBTYPEP `(UNSIGNED-BYTE ,WIDTH) - ;; 'BIGNUM-ELEMENT-TYPE) `(defun ,name ,lambda-list (flet ((prepare-argument (x) (declare (integer x)) (etypecase x ((unsigned-byte ,width) x) - (bignum-element-type (logand x ,pattern)) (fixnum (logand x ,pattern)) - (bignum (logand (%bignum-ref x 0) ,pattern))))) + (bignum (logand x ,pattern))))) (,name ,@(loop for arg in lambda-list collect `(prepare-argument ,arg))))))) (loop for infos being each hash-value of sb!c::*modular-funs*