(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))
+ ;; This used to be (OPTIMIZE (SPEED 3) (SAFETY 3)), but now
+ ;; (0.7.1.39) that (SAFETY 3) means "absolutely safe (including
+ ;; expensive things like %DETECT-STACK-EXHAUSTION)" we get closer
+ ;; to what we want by using (SPEED 2) (SAFETY 2): "pretty fast,
+ ;; pretty safe, and safety is no more important than speed".
+ (declare (optimize (speed 2) (safety 2) (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))))))
+
+;;; 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)
#!+sb-doc
"Destructively sort SEQUENCE. PREDICATE should return non-NIL if
ARG1 is to precede ARG2."
- (typecase sequence
- (simple-vector
- (if (> (the fixnum (length (the simple-vector sequence))) 0)
- (sort-simple-vector sequence predicate key)
- sequence))
- (list
- (sort-list sequence predicate key))
- (vector
- (if (> (the fixnum (length sequence)) 0)
- (sort-vector sequence predicate key)
- sequence))
- (t
- (error 'simple-type-error
- :datum sequence
- :expected-type 'sequence
- :format-control "~S is not a SEQUENCE."
- :format-arguments (list sequence)))))
-\f
-;;;; sorting vectors
-
-;;; Make sorting functions for SIMPLE-VECTOR and miscellaneous other VECTORs.
-(macrolet (;; BUILD-HEAP rearranges seq elements into a heap to start heap
- ;; sorting.
- (build-heap (seq type len-1 pred key)
- (let ((i (gensym)))
- `(do ((,i (floor ,len-1 2) (1- ,i)))
- ((minusp ,i) ,seq)
- (declare (fixnum ,i))
- (heapify ,seq ,type ,i ,len-1 ,pred ,key))))
- ;; HEAPIFY, assuming both sons of root are heaps,
- ;; percolates the root element through the sons to form a
- ;; heap at root. Root and max are zero based coordinates,
- ;; but the heap algorithm only works on arrays indexed from
- ;; 1 through N (not 0 through N-1); This is because a root
- ;; at I has sons at 2*I and 2*I+1 which does not work for a
- ;; root at 0. Because of this, boundaries, roots, and
- ;; termination are computed using 1..N indexes.
- (heapify (seq vector-ref root max pred key)
- (let ((heap-root (gensym))
- (heap-max (gensym))
- (root-ele (gensym))
- (root-key (gensym))
- (heap-max/2 (gensym))
- (heap-l-son (gensym))
- (one-son (gensym))
- (one-son-ele (gensym))
- (one-son-key (gensym))
- (r-son-ele (gensym))
- (r-son-key (gensym))
- (var-root (gensym)))
- `(let* ((,var-root ,root) ; (necessary to not clobber calling
- ; root var)
- (,heap-root (1+ ,root))
- (,heap-max (1+ ,max))
- (,root-ele (,vector-ref ,seq ,root))
- (,root-key (apply-key ,key ,root-ele))
- (,heap-max/2 (ash ,heap-max -1))) ; (floor heap-max 2)
- (declare (fixnum ,var-root ,heap-root ,heap-max ,heap-max/2))
- (loop
- (if (> ,heap-root ,heap-max/2) (return))
- (let* ((,heap-l-son (ash ,heap-root 1)) ; (* 2 heap-root)
- ;; l-son index in seq (0..N-1) is one less than heap
- ;; computation.
- (,one-son (1- ,heap-l-son))
- (,one-son-ele (,vector-ref ,seq ,one-son))
- (,one-son-key (apply-key ,key ,one-son-ele)))
- (declare (fixnum ,heap-l-son ,one-son))
- (if (< ,heap-l-son ,heap-max)
- ;; There is a right son.
- (let* ((,r-son-ele (,vector-ref ,seq ,heap-l-son))
- (,r-son-key (apply-key ,key ,r-son-ele)))
- ;; Choose the greater of the two sons.
- (when (funcall ,pred ,one-son-key ,r-son-key)
- (setf ,one-son ,heap-l-son)
- (setf ,one-son-ele ,r-son-ele)
- (setf ,one-son-key ,r-son-key))))
- ;; If greater son is less than root, then we've
- ;; formed a heap again..
- (if (funcall ,pred ,one-son-key ,root-key) (return))
- ;; ..else put greater son at root and make
- ;; greater son node be the root.
- (setf (,vector-ref ,seq ,var-root) ,one-son-ele)
- (setf ,heap-root (1+ ,one-son)) ; (one plus to be in heap coordinates)
- (setf ,var-root ,one-son))) ; actual index into vector for root ele
- ;; Now really put percolated value into heap at the
- ;; appropriate root node.
- (setf (,vector-ref ,seq ,var-root) ,root-ele))))
- (def-vector-sort-fun (fun-name vector-ref)
- `(defun ,fun-name (seq pred key)
- (let ((len-1 (1- (length (the vector seq)))))
- (declare (fixnum len-1))
- (build-heap seq ,vector-ref len-1 pred key)
- (do* ((i len-1 i-1)
- (i-1 (1- i) (1- i-1)))
- ((zerop i) seq)
- (declare (fixnum i i-1))
- (rotatef (,vector-ref seq 0) (,vector-ref seq i))
- (heapify seq ,vector-ref 0 i-1 pred key))))))
- (def-vector-sort-fun sort-vector aref)
- (def-vector-sort-fun sort-simple-vector svref))
+ (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))))))
\f
;;;; stable sorting
(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).
-
+;;; 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))
) ; EVAL-when
-;;; Temporary vector for stable sorting vectors.
+;;; temporary vector for stable sorting vectors
(defvar *merge-sort-temp-vector*
(make-array 50))
(eval-when (:compile-toplevel :execute)
;;; MERGE-VECTORS returns a new vector which contains an interleaving
-;;; of the elements of vector-1 and vector-2. Elements from vector-2 are
-;;; chosen only if they are strictly less than elements of vector-1,
-;;; (pred elt-2 elt-1), as specified in the manual.
-
+;;; of the elements of VECTOR-1 and VECTOR-2. Elements from VECTOR-2
+;;; 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)
(let ((result-i (gensym))
(defun merge (result-type sequence1 sequence2 predicate &key key)
#!+sb-doc
- "The sequences Sequence1 and Sequence2 are destructively merged into
- a sequence of type Result-Type using the Predicate to order the elements."
+ "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)
(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))))
+ (result (make-sequence-of-type result-type
+ (+ length-1 length-2))))
(declare (vector vector-1 vector-2)
(fixnum length-1 length-2))
- #!+high-security
- (check-type-var result result-type)
+ #!+high-security (aver (typep result result-type))
(if (and (simple-vector-p result)
(simple-vector-p vector-1)
(simple-vector-p vector-2))
projects / sbcl.git / blobdiff