-;;; This checks to see whether the array is simple and the start and
-;;; end are in bounds. If so, it proceeds with those values.
-;;; Otherwise, it calls %WITH-ARRAY-DATA. Note that %WITH-ARRAY-DATA
-;;; may be further optimized.
-;;;
-;;; Given any ARRAY, bind DATA-VAR to the array's data vector and
-;;; START-VAR and END-VAR to the start and end of the designated
-;;; portion of the data vector. SVALUE and EVALUE are any start and
-;;; end specified to the original operation, and are factored into the
-;;; bindings of START-VAR and END-VAR. OFFSET-VAR is the cumulative
-;;; offset of all displacements encountered, and does not include
-;;; SVALUE.
-;;;
-;;; When FORCE-INLINE is set, the underlying %WITH-ARRAY-DATA form is
-;;; forced to be inline, overriding the ordinary judgment of the
-;;; %WITH-ARRAY-DATA DEFTRANSFORMs. Ordinarily the DEFTRANSFORMs are
-;;; fairly picky about their arguments, figuring that if you haven't
-;;; bothered to get all your ducks in a row, you probably don't care
-;;; that much about speed anyway! But in some cases it makes sense to
-;;; do type testing inside %WITH-ARRAY-DATA instead of outside, and
-;;; the DEFTRANSFORM can't tell that that's going on, so it can make
-;;; sense to use FORCE-INLINE option in that case.
-(defmacro with-array-data (((data-var array &key offset-var)
- (start-var &optional (svalue 0))
- (end-var &optional (evalue nil))
- &key force-inline)
- &body forms)
- (once-only ((n-array array)
- (n-svalue `(the index ,svalue))
- (n-evalue `(the (or index null) ,evalue)))
- `(multiple-value-bind (,data-var
- ,start-var
- ,end-var
- ,@(when offset-var `(,offset-var)))
- (if (not (array-header-p ,n-array))
- (let ((,n-array ,n-array))
- (declare (type (simple-array * (*)) ,n-array))
- ,(once-only ((n-len `(length ,n-array))
- (n-end `(or ,n-evalue ,n-len)))
- `(if (<= ,n-svalue ,n-end ,n-len)
- ;; success
- (values ,n-array ,n-svalue ,n-end 0)
- ;; failure: Make a NOTINLINE call to
- ;; %WITH-ARRAY-DATA with our bad data
- ;; to cause the error to be signalled.
- (locally
- (declare (notinline %with-array-data))
- (%with-array-data ,n-array ,n-svalue ,n-evalue)))))
- (,(if force-inline '%with-array-data-macro '%with-array-data)
- ,n-array ,n-svalue ,n-evalue))
- ,@forms)))
-
-;;; This is the fundamental definition of %WITH-ARRAY-DATA, for use in
-;;; DEFTRANSFORMs and DEFUNs.
-(defmacro %with-array-data-macro (array
- start
- end
- &key
- (element-type '*)
- unsafe?
- fail-inline?)
- (let ((size (gensym "SIZE-"))
- (data (gensym "DATA-"))
- (cumulative-offset (gensym "CUMULATIVE-OFFSET-")))
- `(let* ((,size (array-total-size ,array))
- (,end (cond (,end
- (unless (or ,unsafe? (<= ,end ,size))
- ,(if fail-inline?
- `(error "End ~D is greater than total size ~D."
- ,end ,size)
- `(failed-%with-array-data ,array ,start ,end)))
- ,end)
- (t ,size))))
- (unless (or ,unsafe? (<= ,start ,end))
- ,(if fail-inline?
- `(error "Start ~D is greater than end ~D." ,start ,end)
- `(failed-%with-array-data ,array ,start ,end)))
- (do ((,data ,array (%array-data-vector ,data))
- (,cumulative-offset 0
- (+ ,cumulative-offset
- (%array-displacement ,data))))
- ((not (array-header-p ,data))
- (values (the (simple-array ,element-type 1) ,data)
- (the index (+ ,cumulative-offset ,start))
- (the index (+ ,cumulative-offset ,end))
- (the index ,cumulative-offset)))
- (declare (type index ,cumulative-offset))))))
-
-(defun upgraded-element-type-specifier-or-give-up (continuation)
- (let* ((element-ctype (extract-upgraded-element-type continuation))
- (element-type-specifier (type-specifier element-ctype)))
- (if (eq element-type-specifier '*)
- (give-up-ir1-transform
- "upgraded array element type not known at compile time")
- element-type-specifier)))
-
-(deftransform %with-array-data ((array start end)
- ;; Note: This transform is limited to
- ;; VECTOR only because I happened to
- ;; create it in order to get sequence
- ;; function operations to be more
- ;; efficient. It might very well be
- ;; reasonable to allow general ARRAY
- ;; here, I just haven't tried to
- ;; understand the performance issues
- ;; involved. -- WHN
- (vector index (or index null))
- *
- :important t
- :node node
- :policy (> speed space))
- "inline non-SIMPLE-vector-handling logic"
- (let ((element-type (upgraded-element-type-specifier-or-give-up array)))
- `(%with-array-data-macro array start end
- :unsafe? ,(policy node (= safety 0))
- :element-type ,element-type)))
-
-;;; It'd waste space to expand copies of error handling in every
-;;; inline %WITH-ARRAY-DATA, so we have them call this function
-;;; instead. This is just a wrapper which is known never to return.
-(defknown failed-%with-array-data (t t t) nil)
-(defun failed-%with-array-data (array start end)
- (declare (notinline %with-array-data))
- (%with-array-data array start end)
- (error "internal error: shouldn't be here with valid parameters"))
-
-(deftransform fill ((seq item &key (start 0) (end (length seq)))
- (vector t &key (:start t) (:end index))
- *
- :policy (> speed space))
- "open code"
- (let ((element-type (upgraded-element-type-specifier-or-give-up seq)))
- `(with-array-data ((data seq)
- (start start)
- (end end))
- (declare (type (simple-array ,element-type 1) data))
- (do ((i start (1+ i)))
- ((= i end) seq)
- (declare (type index i))
- ;; WITH-ARRAY-DATA does our range checks once and for all, so
- ;; it'd be wasteful to check again on every AREF.
- (declare (optimize (safety 0)))
- (setf (aref data i) item)))))