X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fsort.lisp;h=83e98984ac68a17675f9104bb6098b927a8ceb9a;hb=26265f96389d737bf2e1e4c787ea8943ae499944;hp=49aa8f096ec5e487deb23127ffca6af120153550;hpb=b6aa15328871678a3475e82c150b251dffb49ba1;p=sbcl.git diff --git a/src/code/sort.lisp b/src/code/sort.lisp index 49aa8f0..83e9898 100644 --- a/src/code/sort.lisp +++ b/src/code/sort.lisp @@ -11,232 +11,168 @@ (in-package "SB!IMPL") -;;; Like CMU CL, we use HEAPSORT. However, other than that, this code -;;; isn't really related to the CMU CL code, since instead of trying -;;; to generalize the CMU CL code to allow START and END values, this -;;; code has been written from scratch following Chapter 7 of -;;; _Introduction to Algorithms_ by Corman, Rivest, and Shamir. -(macrolet ((%index (x) `(truly-the index ,x)) - (%parent (i) `(ash ,i -1)) - (%left (i) `(%index (ash ,i 1))) - (%right (i) `(%index (1+ (ash ,i 1)))) - (%heapify (i) - `(do* ((i ,i) - (left (%left i) (%left i))) - ((> left current-heap-size)) - (declare (type index i left)) - (let* ((i-elt (%elt i)) - (i-key (funcall keyfun i-elt)) - (left-elt (%elt left)) - (left-key (funcall keyfun left-elt))) - (multiple-value-bind (large large-elt large-key) - (if (funcall predicate i-key left-key) - (values left left-elt left-key) - (values i i-elt i-key)) - (let ((right (%right i))) - (multiple-value-bind (largest largest-elt) - (if (> right current-heap-size) - (values large large-elt) - (let* ((right-elt (%elt right)) - (right-key (funcall keyfun right-elt))) - (if (funcall predicate large-key right-key) - (values right right-elt) - (values large large-elt)))) - (cond ((= largest i) - (return)) - (t - (setf (%elt i) largest-elt - (%elt largest) i-elt - i largest))))))))) - (%sort-vector (keyfun &optional (vtype 'vector)) - `(macrolet (;; KLUDGE: In SBCL ca. 0.6.10, I had trouble getting - ;; type inference to propagate all the way - ;; through this tangled mess of inlining. The - ;; TRULY-THE here works around that. -- WHN - (%elt (i) - `(aref (truly-the ,',vtype vector) - (%index (+ (%index ,i) start-1))))) - (let ((start-1 (1- start)) ; Heaps prefer 1-based addressing. - (current-heap-size (- end start)) - (keyfun ,keyfun)) - (declare (type (integer -1 #.(1- most-positive-fixnum)) - start-1)) - (declare (type index current-heap-size)) - (declare (type function keyfun)) - (loop for i of-type index - from (ash current-heap-size -1) downto 1 do - (%heapify i)) - (loop - (when (< current-heap-size 2) - (return)) - (rotatef (%elt 1) (%elt current-heap-size)) - (decf current-heap-size) - (%heapify 1)))))) - - (declaim (inline sort-vector)) - (defun sort-vector (vector start end predicate key) - (declare (type vector vector)) - (declare (type index start end)) - (declare (type function predicate)) - (declare (type (or function null) key)) - (declare (optimize (speed 3) (safety 3) (debug 1) (space 1))) - (if (typep vector 'simple-vector) - ;; (VECTOR T) is worth optimizing for, and SIMPLE-VECTOR is - ;; what we get from (VECTOR T) inside WITH-ARRAY-DATA. - (if (null key) - ;; Special-casing the KEY=NIL case lets us avoid some - ;; function calls. - (%sort-vector #'identity simple-vector) - (%sort-vector key simple-vector)) - ;; It's hard to anticipate many speed-critical applications for - ;; sorting vector types other than (VECTOR T), so we just lump - ;; them all together in one slow dynamically typed mess. - (locally - (declare (optimize (speed 2) (space 2) (inhibit-warnings 3))) - (%sort-vector (or key #'identity)))))) +(defun sort-vector (vector start end predicate-fun key-fun-or-nil) + (sort-vector vector start end predicate-fun key-fun-or-nil)) ;;; This is MAYBE-INLINE because it's not too hard to have an ;;; application where sorting is a major bottleneck, and inlining it ;;; allows the compiler to make enough optimizations that it might be ;;; worth the (large) cost in space. (declaim (maybe-inline sort)) -(defun sort (sequence predicate &key key) +(defun sort (sequence predicate &rest args &key key) #!+sb-doc "Destructively sort SEQUENCE. PREDICATE should return non-NIL if ARG1 is to precede ARG2." - (let ((predicate-function (%coerce-callable-to-fun predicate)) - (key-function (and key (%coerce-callable-to-fun key)))) - (typecase sequence - (list (sort-list sequence predicate-function key-function)) - (vector - (with-array-data ((vector (the vector sequence)) - (start 0) - (end (length sequence))) - (sort-vector vector start end predicate-function key-function)) - sequence) - (t - (error 'simple-type-error - :datum sequence - :expected-type 'sequence - :format-control "~S is not a sequence." - :format-arguments (list sequence)))))) + (declare (dynamic-extent args)) + (let ((predicate-fun (%coerce-callable-to-fun predicate))) + (seq-dispatch sequence + (stable-sort-list sequence + predicate-fun + (if key (%coerce-callable-to-fun key) #'identity)) + (let ((key-fun-or-nil (and key (%coerce-callable-to-fun key)))) + (with-array-data ((vector (the vector sequence)) + (start) + (end) + :check-fill-pointer t) + (sort-vector vector start end predicate-fun key-fun-or-nil)) + sequence) + (apply #'sb!sequence:sort sequence predicate args)))) ;;;; stable sorting - -(defun stable-sort (sequence predicate &key key) +(defun stable-sort (sequence predicate &rest args &key key) #!+sb-doc - "Destructively sorts sequence. Predicate should return non-Nil if - Arg1 is to precede Arg2." - (typecase sequence - (simple-vector - (stable-sort-simple-vector sequence predicate key)) - (list - (sort-list sequence predicate key)) - (vector - (stable-sort-vector sequence predicate key)) - (t - (error 'simple-type-error - :datum sequence - :expected-type 'sequence - :format-control "~S is not a sequence." - :format-arguments (list sequence))))) + "Destructively sort SEQUENCE. PREDICATE should return non-NIL if + ARG1 is to precede ARG2." + (declare (dynamic-extent args)) + (let ((predicate-fun (%coerce-callable-to-fun predicate))) + (seq-dispatch sequence + (stable-sort-list sequence + predicate-fun + (if key (%coerce-callable-to-fun key) #'identity)) + (if (typep sequence 'simple-vector) + (stable-sort-simple-vector sequence + predicate-fun + (and key (%coerce-callable-to-fun key))) + (stable-sort-vector sequence + predicate-fun + (and key (%coerce-callable-to-fun key)))) + (apply #'sb!sequence:stable-sort sequence predicate args)))) + +;;; FUNCALL-USING-KEY saves us a function call sometimes. +(eval-when (:compile-toplevel :execute) + (sb!xc:defmacro funcall2-using-key (pred key one two) + `(if ,key + (funcall ,pred (funcall ,key ,one) + (funcall ,key ,two)) + (funcall ,pred ,one ,two))) +) ; EVAL-WHEN + +;;;; stable sort of lists -;;; stable sort of lists +(defun last-cons-of (list) + (loop (let ((rest (rest list))) + (if rest + (setf list rest) + (return list))))) -;;; SORT-LIST uses a bottom up merge sort. First a pass is made over -;;; the list grabbing one element at a time and merging it with the -;;; next one form pairs of sorted elements. Then n is doubled, and -;;; elements are taken in runs of two, merging one run with the next -;;; to form quadruples of sorted elements. This continues until n is -;;; large enough that the inner loop only runs for one iteration; that -;;; is, there are only two runs that can be merged, the first run +;;; Destructively merge LIST-1 with LIST-2 (given that they're already +;;; sorted w.r.t. PRED-FUN on KEY-FUN, giving output sorted the same +;;; way). In the resulting list, elements of LIST-1 are guaranteed to +;;; come before equal elements of LIST-2. +;;; +;;; Return (VALUES HEAD TAILTAIL), where HEAD is the same value you'd +;;; expect from MERGE, and TAILTAIL is the last cons in the list (i.e. +;;; the last cons in the list which NRECONC calls TAIL). +(defun merge-lists* (list-1 list-2 pred-fun key-fun) + (declare (type list list-1 list-2)) + (declare (type function pred-fun key-fun)) + (cond ((null list-1) (values list-2 (last-cons-of list-2))) + ((null list-2) (values list-1 (last-cons-of list-1))) + (t (let* ((reversed-result-so-far nil) + (key-1 (funcall key-fun (car list-1))) + (key-2 (funcall key-fun (car list-2)))) + (loop + (macrolet ((frob (list-i key-i other-list) + `(progn + ;; basically + ;; (PUSH (POP ,LIST-I) REVERSED-RESULT-SO-FAR), + ;; except doing some fancy footwork to + ;; reuse the cons cell: + (psetf (cdr ,list-i) reversed-result-so-far + reversed-result-so-far ,list-i + ,list-i (cdr ,list-i)) + ;; Now maybe we're done. + (if (endp ,list-i) + (return (values (nreconc + reversed-result-so-far + ,other-list) + (last-cons-of + ,other-list))) + (setf ,key-i + (funcall key-fun (car ,list-i))))))) + ;; Note that by making KEY-2 the first arg to + ;; PRED-FUN, we arrange that if PRED-FUN is a function + ;; in the #'< style, the outcome is stably sorted. + (if (funcall pred-fun key-2 key-1) + (frob list-2 key-2 list-1) + (frob list-1 key-1 list-2)))))))) + +;;; STABLE-SORT-LIST uses a bottom-up merge sort. First a pass is made +;;; over the list grabbing one element at a time and merging it with +;;; the next one to form pairs of sorted elements. Then N is doubled, +;;; and elements are taken in runs of two, merging one run with the +;;; next to form quadruples of sorted elements. This continues until N +;;; is large enough that the inner loop only runs for one iteration; +;;; that is, there are only two runs that can be merged, the first run ;;; starting at the beginning of the list, and the second being the ;;; remaining elements. - -(defun sort-list (list pred key) +(defun stable-sort-list (list pred-fun key-fun) (let ((head (cons :header list)) ; head holds on to everything - (n 1) ; bottom-up size of lists to be merged - unsorted ; unsorted is the remaining list to be - ; broken into n size lists and merged - list-1 ; list-1 is one length n list to be merged - last) ; last points to the last visited cell - (declare (fixnum n)) + (n 1) ; bottom-up size of lists to be merged + unsorted ; unsorted is the remaining list to be + ; broken into n size lists and merged + list-1 ; list-1 is one length n list to be merged + last) ; last points to the last visited cell + (declare (type function pred-fun key-fun) + (type fixnum n)) (loop - ;; start collecting runs of n at the first element + ;; Start collecting runs of N at the first element. (setf unsorted (cdr head)) - ;; tack on the first merge of two n-runs to the head holder + ;; Tack on the first merge of two N-runs to the head holder. (setf last head) (let ((n-1 (1- n))) (declare (fixnum n-1)) (loop - (setf list-1 unsorted) - (let ((temp (nthcdr n-1 list-1)) - list-2) - (cond (temp - ;; there are enough elements for a second run - (setf list-2 (cdr temp)) - (setf (cdr temp) nil) - (setf temp (nthcdr n-1 list-2)) - (cond (temp - (setf unsorted (cdr temp)) - (setf (cdr temp) nil)) - ;; the second run goes off the end of the list - (t (setf unsorted nil))) - (multiple-value-bind (merged-head merged-last) - (merge-lists* list-1 list-2 pred key) - (setf (cdr last) merged-head) - (setf last merged-last)) - (if (null unsorted) (return))) - ;; if there is only one run, then tack it on to the end - (t (setf (cdr last) list-1) - (return))))) + (setf list-1 unsorted) + (let ((temp (nthcdr n-1 list-1)) + list-2) + (cond (temp + ;; There are enough elements for a second run. + (setf list-2 (cdr temp)) + (setf (cdr temp) nil) + (setf temp (nthcdr n-1 list-2)) + (cond (temp + (setf unsorted (cdr temp)) + (setf (cdr temp) nil)) + ;; The second run goes off the end of the list. + (t (setf unsorted nil))) + (multiple-value-bind (merged-head merged-last) + (merge-lists* list-1 list-2 pred-fun key-fun) + (setf (cdr last) merged-head + last merged-last)) + (if (null unsorted) (return))) + ;; If there is only one run, then tack it on to the end. + (t (setf (cdr last) list-1) + (return))))) (setf n (ash n 1)) ; (+ n n) ;; If the inner loop only executed once, then there were only ;; enough elements for two runs given n, so all the elements ;; have been merged into one list. This may waste one outer ;; iteration to realize. (if (eq list-1 (cdr head)) - (return list-1)))))) - -;;; APPLY-PRED saves us a function call sometimes. -(eval-when (:compile-toplevel :execute) - (sb!xc:defmacro apply-pred (one two pred key) - `(if ,key - (funcall ,pred (funcall ,key ,one) - (funcall ,key ,two)) - (funcall ,pred ,one ,two))) -) ; EVAL-WHEN - -(defvar *merge-lists-header* (list :header)) - -;;; MERGE-LISTS* originally written by Jim Large. -;;; modified to return a pointer to the end of the result -;;; and to not cons header each time its called. -;;; It destructively merges list-1 with list-2. In the resulting -;;; list, elements of list-2 are guaranteed to come after equal elements -;;; of list-1. -(defun merge-lists* (list-1 list-2 pred key) - (do* ((result *merge-lists-header*) - (P result)) ; points to last cell of result - ((or (null list-1) (null list-2)) ; done when either list used up - (if (null list-1) ; in which case, append the - (rplacd p list-2) ; other list - (rplacd p list-1)) - (do ((drag p lead) - (lead (cdr p) (cdr lead))) - ((null lead) - (values (prog1 (cdr result) ; Return the result sans header - (rplacd result nil)) ; (free memory, be careful) - drag)))) ; and return pointer to last element. - (cond ((apply-pred (car list-2) (car list-1) pred key) - (rplacd p list-2) ; Append the lesser list to last cell of - (setq p (cdr p)) ; result. Note: test must bo done for - (pop list-2)) ; LIST-2 < LIST-1 so merge will be - (T (rplacd p list-1) ; stable for LIST-1. - (setq p (cdr p)) - (pop list-1))))) - -;;; stable sort of vectors + (return list-1)))))) + +;;;; stable sort of vectors ;;; Stable sorting vectors is done with the same algorithm used for ;;; lists, using a temporary vector to merge back and forth between it @@ -250,125 +186,132 @@ ;;; and merges them into a target vector starting at index start-1. (sb!xc:defmacro stable-sort-merge-vectors* (source target start-1 end-1 end-2 - pred key source-ref - target-ref) + pred key source-ref + target-ref) (let ((i (gensym)) - (j (gensym)) - (target-i (gensym))) + (j (gensym)) + (target-i (gensym))) `(let ((,i ,start-1) - (,j ,end-1) ; start-2 - (,target-i ,start-1)) + (,j ,end-1) ; start-2 + (,target-i ,start-1)) (declare (fixnum ,i ,j ,target-i)) (loop - (cond ((= ,i ,end-1) - (loop (if (= ,j ,end-2) (return)) - (setf (,target-ref ,target ,target-i) - (,source-ref ,source ,j)) - (incf ,target-i) - (incf ,j)) - (return)) - ((= ,j ,end-2) - (loop (if (= ,i ,end-1) (return)) - (setf (,target-ref ,target ,target-i) - (,source-ref ,source ,i)) - (incf ,target-i) - (incf ,i)) - (return)) - ((apply-pred (,source-ref ,source ,j) - (,source-ref ,source ,i) - ,pred ,key) - (setf (,target-ref ,target ,target-i) - (,source-ref ,source ,j)) - (incf ,j)) - (t (setf (,target-ref ,target ,target-i) - (,source-ref ,source ,i)) - (incf ,i))) - (incf ,target-i))))) + (cond ((= ,i ,end-1) + (loop (if (= ,j ,end-2) (return)) + (setf (,target-ref ,target ,target-i) + (,source-ref ,source ,j)) + (incf ,target-i) + (incf ,j)) + (return)) + ((= ,j ,end-2) + (loop (if (= ,i ,end-1) (return)) + (setf (,target-ref ,target ,target-i) + (,source-ref ,source ,i)) + (incf ,target-i) + (incf ,i)) + (return)) + ((funcall2-using-key ,pred ,key + (,source-ref ,source ,j) + (,source-ref ,source ,i)) + (setf (,target-ref ,target ,target-i) + (,source-ref ,source ,j)) + (incf ,j)) + (t (setf (,target-ref ,target ,target-i) + (,source-ref ,source ,i)) + (incf ,i))) + (incf ,target-i))))) ;;; VECTOR-MERGE-SORT is the same algorithm used to stable sort lists, ;;; but it uses a temporary vector. DIRECTION determines whether we ;;; are merging into the temporary (T) or back into the given vector ;;; (NIL). (sb!xc:defmacro vector-merge-sort (vector pred key vector-ref) - (let ((vector-len (gensym)) (n (gensym)) - (direction (gensym)) (unsorted (gensym)) - (start-1 (gensym)) (end-1 (gensym)) - (end-2 (gensym)) (temp-len (gensym)) - (i (gensym))) - `(let ((,vector-len (length (the vector ,vector))) - (,n 1) ; bottom-up size of contiguous runs to be merged - (,direction t) ; t vector --> temp nil temp --> vector - (,temp-len (length (the simple-vector *merge-sort-temp-vector*))) - (,unsorted 0) ; unsorted..vector-len are the elements that need - ; to be merged for a given n - (,start-1 0)) ; one n-len subsequence to be merged with the next - (declare (fixnum ,vector-len ,n ,temp-len ,unsorted ,start-1)) - (if (> ,vector-len ,temp-len) - (setf *merge-sort-temp-vector* - (make-array (max ,vector-len (+ ,temp-len ,temp-len))))) - (loop - ;; for each n, we start taking n-runs from the start of the vector - (setf ,unsorted 0) - (loop - (setf ,start-1 ,unsorted) - (let ((,end-1 (+ ,start-1 ,n))) - (declare (fixnum ,end-1)) - (cond ((< ,end-1 ,vector-len) - ;; there are enough elements for a second run - (let ((,end-2 (+ ,end-1 ,n))) - (declare (fixnum ,end-2)) - (if (> ,end-2 ,vector-len) (setf ,end-2 ,vector-len)) - (setf ,unsorted ,end-2) - (if ,direction - (stable-sort-merge-vectors* - ,vector *merge-sort-temp-vector* - ,start-1 ,end-1 ,end-2 ,pred ,key ,vector-ref svref) - (stable-sort-merge-vectors* - *merge-sort-temp-vector* ,vector - ,start-1 ,end-1 ,end-2 ,pred ,key svref ,vector-ref)) - (if (= ,unsorted ,vector-len) (return)))) - ;; if there is only one run, copy those elements to the end - (t (if ,direction - (do ((,i ,start-1 (1+ ,i))) - ((= ,i ,vector-len)) - (declare (fixnum ,i)) - (setf (svref *merge-sort-temp-vector* ,i) - (,vector-ref ,vector ,i))) - (do ((,i ,start-1 (1+ ,i))) - ((= ,i ,vector-len)) - (declare (fixnum ,i)) - (setf (,vector-ref ,vector ,i) - (svref *merge-sort-temp-vector* ,i)))) - (return))))) - ;; If the inner loop only executed once, then there were only enough - ;; elements for two subsequences given n, so all the elements have - ;; been merged into one list. Start-1 will have remained 0 upon exit. - (when (zerop ,start-1) - (if ,direction - ;; if we just merged into the temporary, copy it all back - ;; to the given vector. - (dotimes (,i ,vector-len) - (setf (,vector-ref ,vector ,i) - (svref *merge-sort-temp-vector* ,i)))) - (return ,vector)) - (setf ,n (ash ,n 1)) ; (* 2 n) - (setf ,direction (not ,direction)))))) + (with-unique-names + (vector-len n direction unsorted start-1 end-1 end-2 temp temp-len i) + `(let* ((,vector-len (length (the vector ,vector))) + (,n 1) ; bottom-up size of contiguous runs to be merged + (,direction t) ; t vector --> temp nil temp --> vector + (,temp *merge-sort-temp-vector*) + (,temp-len (length ,temp)) + (,unsorted 0) ; unsorted..vector-len are the elements that need + ; to be merged for a given n + (,start-1 0)) ; one n-len subsequence to be merged with the next + (declare (fixnum ,vector-len ,n ,temp-len ,unsorted ,start-1) + (simple-vector ,temp)) + (when (> ,vector-len ,temp-len) + (setf ,temp (make-array (max ,vector-len + (min most-positive-fixnum + (+ ,temp-len ,temp-len)))) + *merge-sort-temp-vector* ,temp)) + ;; Rebind, in case PRED or KEY calls STABLE-SORT. This is also + ;; interrupt safe: we bind before we put any data of our own in + ;; the temp vector. + (let ((*merge-sort-temp-vector* (vector))) + (loop + ;; for each n, we start taking n-runs from the start of the vector + (setf ,unsorted 0) + (loop + (setf ,start-1 ,unsorted) + (let ((,end-1 (+ ,start-1 ,n))) + (declare (fixnum ,end-1)) + (cond ((< ,end-1 ,vector-len) + ;; there are enough elements for a second run + (let ((,end-2 (+ ,end-1 ,n))) + (declare (fixnum ,end-2)) + (if (> ,end-2 ,vector-len) (setf ,end-2 ,vector-len)) + (setf ,unsorted ,end-2) + (if ,direction + (stable-sort-merge-vectors* + ,vector ,temp + ,start-1 ,end-1 ,end-2 ,pred ,key ,vector-ref svref) + (stable-sort-merge-vectors* + ,temp ,vector + ,start-1 ,end-1 ,end-2 ,pred ,key svref ,vector-ref)) + (if (= ,unsorted ,vector-len) (return)))) + ;; if there is only one run, copy those elements to the end + (t (if ,direction + (do ((,i ,start-1 (1+ ,i))) + ((= ,i ,vector-len)) + (declare (fixnum ,i)) + (setf (svref ,temp ,i) + (,vector-ref ,vector ,i))) + (do ((,i ,start-1 (1+ ,i))) + ((= ,i ,vector-len)) + (declare (fixnum ,i)) + (setf (,vector-ref ,vector ,i) + (svref ,temp ,i)))) + (return))))) + ;; If the inner loop only executed once, then there were only enough + ;; elements for two subsequences given n, so all the elements have + ;; been merged into one list. Start-1 will have remained 0 upon exit. + (when (zerop ,start-1) + (if ,direction + ;; if we just merged into the temporary, copy it all back + ;; to the given vector. + (dotimes (,i ,vector-len) + (setf (,vector-ref ,vector ,i) + (svref ,temp ,i)))) + (return ,vector)) + (setf ,n (ash ,n 1)) ; (* 2 n) + (setf ,direction (not ,direction))))))) ) ; EVAL-when -;;; temporary vector for stable sorting vectors -(defvar *merge-sort-temp-vector* - (make-array 50)) - +;;; temporary vector for stable sorting vectors, allocated for each new thread +(defvar *merge-sort-temp-vector* (vector)) (declaim (simple-vector *merge-sort-temp-vector*)) (defun stable-sort-simple-vector (vector pred key) - (declare (simple-vector vector)) + (declare (type simple-vector vector) + (type function pred) + (type (or null function) key)) (vector-merge-sort vector pred key svref)) (defun stable-sort-vector (vector pred key) + (declare (type function pred) + (type (or null function) key)) (vector-merge-sort vector pred key aref)) - + ;;;; merging (eval-when (:compile-toplevel :execute) @@ -378,38 +321,38 @@ ;;; are chosen only if they are strictly less than elements of ;;; VECTOR-1, (PRED ELT-2 ELT-1), as specified in the manual. (sb!xc:defmacro merge-vectors (vector-1 length-1 vector-2 length-2 - result-vector pred key access) + result-vector pred key access) (let ((result-i (gensym)) - (i (gensym)) - (j (gensym))) + (i (gensym)) + (j (gensym))) `(let* ((,result-i 0) - (,i 0) - (,j 0)) + (,i 0) + (,j 0)) (declare (fixnum ,result-i ,i ,j)) (loop - (cond ((= ,i ,length-1) - (loop (if (= ,j ,length-2) (return)) - (setf (,access ,result-vector ,result-i) - (,access ,vector-2 ,j)) - (incf ,result-i) - (incf ,j)) - (return ,result-vector)) - ((= ,j ,length-2) - (loop (if (= ,i ,length-1) (return)) - (setf (,access ,result-vector ,result-i) - (,access ,vector-1 ,i)) - (incf ,result-i) - (incf ,i)) - (return ,result-vector)) - ((apply-pred (,access ,vector-2 ,j) (,access ,vector-1 ,i) - ,pred ,key) - (setf (,access ,result-vector ,result-i) - (,access ,vector-2 ,j)) - (incf ,j)) - (t (setf (,access ,result-vector ,result-i) - (,access ,vector-1 ,i)) - (incf ,i))) - (incf ,result-i))))) + (cond ((= ,i ,length-1) + (loop (if (= ,j ,length-2) (return)) + (setf (,access ,result-vector ,result-i) + (,access ,vector-2 ,j)) + (incf ,result-i) + (incf ,j)) + (return ,result-vector)) + ((= ,j ,length-2) + (loop (if (= ,i ,length-1) (return)) + (setf (,access ,result-vector ,result-i) + (,access ,vector-1 ,i)) + (incf ,result-i) + (incf ,i)) + (return ,result-vector)) + ((funcall2-using-key ,pred ,key + (,access ,vector-2 ,j) (,access ,vector-1 ,i)) + (setf (,access ,result-vector ,result-i) + (,access ,vector-2 ,j)) + (incf ,j)) + (t (setf (,access ,result-vector ,result-i) + (,access ,vector-1 ,i)) + (incf ,i))) + (incf ,result-i))))) ) ; EVAL-WHEN @@ -417,25 +360,76 @@ #!+sb-doc "Merge the sequences SEQUENCE1 and SEQUENCE2 destructively into a sequence of type RESULT-TYPE using PREDICATE to order the elements." - (if (eq result-type 'list) - (let ((result (merge-lists* (coerce sequence1 'list) - (coerce sequence2 'list) - predicate key))) - result) - (let* ((vector-1 (coerce sequence1 'vector)) - (vector-2 (coerce sequence2 'vector)) - (length-1 (length vector-1)) - (length-2 (length vector-2)) - (result (make-sequence-of-type result-type - (+ length-1 length-2)))) - (declare (vector vector-1 vector-2) - (fixnum length-1 length-2)) - - #!+high-security (aver (typep result result-type)) - (if (and (simple-vector-p result) - (simple-vector-p vector-1) - (simple-vector-p vector-2)) - (merge-vectors vector-1 length-1 vector-2 length-2 - result predicate key svref) - (merge-vectors vector-1 length-1 vector-2 length-2 - result predicate key aref))))) + ;; FIXME: This implementation is remarkably inefficient in various + ;; ways. In decreasing order of estimated user astonishment, I note: + ;; full calls to SPECIFIER-TYPE at runtime; copying input vectors + ;; to lists before doing MERGE-LISTS*; and walking input lists + ;; (because of the call to MERGE-LISTS*, which walks the list to + ;; find the last element for its second return value) even in cases + ;; like (MERGE 'LIST (LIST 1) (LIST 2 3 4 5 ... 1000)) where one list + ;; can be largely ignored. -- WHN 2003-01-05 + (let ((type (specifier-type result-type))) + (cond + ((csubtypep type (specifier-type 'list)) + ;; the VECTOR clause, below, goes through MAKE-SEQUENCE, so + ;; benefits from the error checking there. Short of + ;; reimplementing everything, we can't do the same for the LIST + ;; case, so do relevant length checking here: + (let ((s1 (coerce sequence1 'list)) + (s2 (coerce sequence2 'list)) + (pred-fun (%coerce-callable-to-fun predicate)) + (key-fun (if key + (%coerce-callable-to-fun key) + #'identity))) + (when (type= type (specifier-type 'list)) + (return-from merge (values (merge-lists* s1 s2 pred-fun key-fun)))) + (when (eq type *empty-type*) + (bad-sequence-type-error nil)) + (when (type= type (specifier-type 'null)) + (if (and (null s1) (null s2)) + (return-from merge 'nil) + ;; FIXME: This will break on circular lists (as, + ;; indeed, will the whole MERGE function). + (sequence-type-length-mismatch-error type + (+ (length s1) + (length s2))))) + (if (cons-type-p type) + (multiple-value-bind (min exactp) + (sb!kernel::cons-type-length-info type) + (let ((length (+ (length s1) (length s2)))) + (if exactp + (unless (= length min) + (sequence-type-length-mismatch-error type length)) + (unless (>= length min) + (sequence-type-length-mismatch-error type length))) + (values (merge-lists* s1 s2 pred-fun key-fun)))) + (sequence-type-too-hairy result-type)))) + ((csubtypep type (specifier-type 'vector)) + (let* ((vector-1 (coerce sequence1 'vector)) + (vector-2 (coerce sequence2 'vector)) + (length-1 (length vector-1)) + (length-2 (length vector-2)) + (result (make-sequence result-type (+ length-1 length-2)))) + (declare (vector vector-1 vector-2) + (fixnum length-1 length-2)) + (if (and (simple-vector-p result) + (simple-vector-p vector-1) + (simple-vector-p vector-2)) + (merge-vectors vector-1 length-1 vector-2 length-2 + result predicate key svref) + (merge-vectors vector-1 length-1 vector-2 length-2 + result predicate key aref)))) + ((and (csubtypep type (specifier-type 'sequence)) + (find-class result-type nil)) + (let* ((vector-1 (coerce sequence1 'vector)) + (vector-2 (coerce sequence2 'vector)) + (length-1 (length vector-1)) + (length-2 (length vector-2)) + (temp (make-array (+ length-1 length-2))) + (result (make-sequence result-type (+ length-1 length-2)))) + (declare (vector vector-1 vector-2) (fixnum length-1 length-2)) + (merge-vectors vector-1 length-1 vector-2 length-2 + temp predicate key aref) + (replace result temp) + result)) + (t (bad-sequence-type-error result-type)))))