- ;; 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))))))
+ ;; 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))))))