src/code/array.lisp

   1 ;;;; functions to implement arrays
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!IMPL")
  13
  14 #!-sb-fluid
  15 (declaim (inline fill-pointer array-has-fill-pointer-p adjustable-array-p
  16                  array-displacement))
  17 \f
  18 ;;;; miscellaneous accessor functions
  19
  20 ;;; These functions are only needed by the interpreter, 'cause the
  21 ;;; compiler inlines them.
  22 (macrolet ((def (name)
  23              `(progn
  24                 (defun ,name (array)
  25                   (,name array))
  26                 (defun (setf ,name) (value array)
  27                   (setf (,name array) value)))))
  28   (def %array-fill-pointer)
  29   (def %array-fill-pointer-p)
  30   (def %array-available-elements)
  31   (def %array-data-vector)
  32   (def %array-displacement)
  33   (def %array-displaced-p))
  34
  35 (defun %array-rank (array)
  36   (%array-rank array))
  37
  38 (defun %array-dimension (array axis)
  39   (%array-dimension array axis))
  40
  41 (defun %set-array-dimension (array axis value)
  42   (%set-array-dimension array axis value))
  43
  44 (defun %check-bound (array bound index)
  45   (declare (type index bound)
  46            (fixnum index))
  47   (%check-bound array bound index))
  48
  49 (defun %with-array-data/fp (array start end)
  50   (%with-array-data-macro array start end :check-bounds t :check-fill-pointer t))
  51
  52 (defun %with-array-data (array start end)
  53   (%with-array-data-macro array start end :check-bounds t :check-fill-pointer nil))
  54
  55 (defun %data-vector-and-index (array index)
  56   (if (array-header-p array)
  57       (multiple-value-bind (vector index)
  58           (%with-array-data array index nil)
  59         (values vector index))
  60       (values array index)))
  61 \f
  62 ;;;; MAKE-ARRAY
  63 (eval-when (:compile-toplevel :execute)
  64   (sb!xc:defmacro pick-vector-type (type &rest specs)
  65     `(cond ,@(mapcar (lambda (spec)
  66                        `(,(if (eq (car spec) t)
  67                               t
  68                               `(subtypep ,type ',(car spec)))
  69                          ,@(cdr spec)))
  70                      specs))))
  71
  72 ;;; These functions are used in the implementation of MAKE-ARRAY for
  73 ;;; complex arrays. There are lots of transforms to simplify
  74 ;;; MAKE-ARRAY for various easy cases, but not for all reasonable
  75 ;;; cases, so e.g. as of sbcl-0.6.6 we still make full calls to
  76 ;;; MAKE-ARRAY for any non-simple array. Thus, there's some value to
  77 ;;; making this somewhat efficient, at least not doing full calls to
  78 ;;; SUBTYPEP in the easy cases.
  79 (defun %vector-widetag-and-n-bits (type)
  80   (case type
  81     ;; Pick off some easy common cases.
  82     ;;
  83     ;; (Perhaps we should make a much more exhaustive table of easy
  84     ;; common cases here. Or perhaps the effort would be better spent
  85     ;; on smarter compiler transforms which do the calculation once
  86     ;; and for all in any reasonable user programs.)
  87     ((t)
  88      (values #.sb!vm:simple-vector-widetag #.sb!vm:n-word-bits))
  89     ((base-char standard-char #!-sb-unicode character)
  90      (values #.sb!vm:simple-base-string-widetag #.sb!vm:n-byte-bits))
  91     #!+sb-unicode
  92     ((character)
  93      (values #.sb!vm:simple-character-string-widetag #.sb!vm:n-word-bits))
  94     ((bit)
  95      (values #.sb!vm:simple-bit-vector-widetag 1))
  96     ;; OK, we have to wade into SUBTYPEPing after all.
  97     (t
  98      #.`(pick-vector-type type
  99          ,@(map 'list
 100                 (lambda (saetp)
 101                   `(,(sb!vm:saetp-specifier saetp)
 102                     (values ,(sb!vm:saetp-typecode saetp)
 103                             ,(sb!vm:saetp-n-bits saetp))))
 104                 sb!vm:*specialized-array-element-type-properties*)))))
 105
 106 (defun %complex-vector-widetag (type)
 107   (case type
 108     ;; Pick off some easy common cases.
 109     ((t)
 110      #.sb!vm:complex-vector-widetag)
 111     ((base-char #!-sb-unicode character)
 112      #.sb!vm:complex-base-string-widetag)
 113     #!+sb-unicode
 114     ((character)
 115      #.sb!vm:complex-character-string-widetag)
 116     ((nil)
 117      #.sb!vm:complex-vector-nil-widetag)
 118     ((bit)
 119      #.sb!vm:complex-bit-vector-widetag)
 120     ;; OK, we have to wade into SUBTYPEPing after all.
 121     (t
 122      (pick-vector-type type
 123        (nil #.sb!vm:complex-vector-nil-widetag)
 124        #!-sb-unicode
 125        (character #.sb!vm:complex-base-string-widetag)
 126        #!+sb-unicode
 127        (base-char #.sb!vm:complex-base-string-widetag)
 128        #!+sb-unicode
 129        (character #.sb!vm:complex-character-string-widetag)
 130        (bit #.sb!vm:complex-bit-vector-widetag)
 131        (t #.sb!vm:complex-vector-widetag)))))
 132
 133 (defun make-array (dimensions &key
 134                               (element-type t)
 135                               (initial-element nil initial-element-p)
 136                               (initial-contents nil initial-contents-p)
 137                               adjustable fill-pointer
 138                               displaced-to displaced-index-offset)
 139   (let* ((dimensions (if (listp dimensions) dimensions (list dimensions)))
 140          (array-rank (length (the list dimensions)))
 141          (simple (and (null fill-pointer)
 142                       (not adjustable)
 143                       (null displaced-to))))
 144     (declare (fixnum array-rank))
 145     (when (and displaced-index-offset (null displaced-to))
 146       (error "can't specify :DISPLACED-INDEX-OFFSET without :DISPLACED-TO"))
 147     (when (and displaced-to
 148                (arrayp displaced-to)
 149                (not (equal (array-element-type displaced-to)
 150                            (upgraded-array-element-type element-type))))
 151       (error "Array element type of :DISPLACED-TO array does not match specified element type"))
 152     (if (and simple (= array-rank 1))
 153         ;; it's a (SIMPLE-ARRAY * (*))
 154         (multiple-value-bind (type n-bits)
 155             (%vector-widetag-and-n-bits element-type)
 156           (declare (type (unsigned-byte 8) type)
 157                    (type (integer 0 256) n-bits))
 158           (let* ((length (car dimensions))
 159                  (array (allocate-vector
 160                          type
 161                          length
 162                          (ceiling
 163                           (* (if (or (= type sb!vm:simple-base-string-widetag)
 164                                      #!+sb-unicode
 165                                      (= type
 166                                         sb!vm:simple-character-string-widetag))
 167                                  (1+ length)
 168                                  length)
 169                              n-bits)
 170                           sb!vm:n-word-bits))))
 171             (declare (type index length))
 172             (when initial-element-p
 173               (fill array initial-element))
 174             (when initial-contents-p
 175               (when initial-element-p
 176                 (error "can't specify both :INITIAL-ELEMENT and ~
 177                        :INITIAL-CONTENTS"))
 178               (unless (= length (length initial-contents))
 179                 (error "There are ~W elements in the :INITIAL-CONTENTS, but ~
 180                        the vector length is ~W."
 181                        (length initial-contents)
 182                        length))
 183               (replace array initial-contents))
 184             array))
 185         ;; it's either a complex array or a multidimensional array.
 186         (let* ((total-size (reduce #'* dimensions))
 187                (data (or displaced-to
 188                          (data-vector-from-inits
 189                           dimensions total-size element-type
 190                           initial-contents initial-contents-p
 191                           initial-element initial-element-p)))
 192                (array (make-array-header
 193                        (cond ((= array-rank 1)
 194                               (%complex-vector-widetag element-type))
 195                              (simple sb!vm:simple-array-widetag)
 196                              (t sb!vm:complex-array-widetag))
 197                        array-rank)))
 198           (cond (fill-pointer
 199                  (unless (= array-rank 1)
 200                    (error "Only vectors can have fill pointers."))
 201                  (let ((length (car dimensions)))
 202                    (declare (fixnum length))
 203                    (setf (%array-fill-pointer array)
 204                      (cond ((eq fill-pointer t)
 205                             length)
 206                            (t
 207                             (unless (and (fixnump fill-pointer)
 208                                          (>= fill-pointer 0)
 209                                          (<= fill-pointer length))
 210                               ;; FIXME: should be TYPE-ERROR?
 211                               (error "invalid fill-pointer ~W"
 212                                      fill-pointer))
 213                             fill-pointer))))
 214                  (setf (%array-fill-pointer-p array) t))
 215                 (t
 216                  (setf (%array-fill-pointer array) total-size)
 217                  (setf (%array-fill-pointer-p array) nil)))
 218           (setf (%array-available-elements array) total-size)
 219           (setf (%array-data-vector array) data)
 220           (cond (displaced-to
 221                  (when (or initial-element-p initial-contents-p)
 222                    (error "Neither :INITIAL-ELEMENT nor :INITIAL-CONTENTS ~
 223                    can be specified along with :DISPLACED-TO"))
 224                  (let ((offset (or displaced-index-offset 0)))
 225                    (when (> (+ offset total-size)
 226                             (array-total-size displaced-to))
 227                      (error "~S doesn't have enough elements." displaced-to))
 228                    (setf (%array-displacement array) offset)
 229                    (setf (%array-displaced-p array) t)))
 230                 (t
 231                  (setf (%array-displaced-p array) nil)))
 232           (let ((axis 0))
 233             (dolist (dim dimensions)
 234               (setf (%array-dimension array axis) dim)
 235               (incf axis)))
 236           array))))
 237
 238 (defun make-static-vector (length &key
 239                            (element-type '(unsigned-byte 8))
 240                            (initial-contents nil initial-contents-p)
 241                            (initial-element nil initial-element-p))
 242   "Allocate vector of LENGTH elements in static space. Only allocation
 243 of specialized arrays is supported."
 244   ;; STEP 1: check inputs fully
 245   ;;
 246   ;; This way of doing explicit checks before the vector is allocated
 247   ;; is expensive, but probably worth the trouble as once we've allocated
 248   ;; the vector we have no way to get rid of it anymore...
 249   (when (eq t (upgraded-array-element-type element-type))
 250     (error "Static arrays of type ~S not supported."
 251            element-type))
 252   (when initial-contents-p
 253     (when initial-element-p
 254       (error "can't specify both :INITIAL-ELEMENT and :INITIAL-CONTENTS"))
 255     (unless (= length (length initial-contents))
 256       (error "There are ~W elements in the :INITIAL-CONTENTS, but the ~
 257               vector length is ~W."
 258              (length initial-contents)
 259              length))
 260     (unless (every (lambda (x) (typep x element-type)) initial-contents)
 261       (error ":INITIAL-CONTENTS contains elements not of type ~S."
 262              element-type)))
 263   (when initial-element-p
 264     (unless (typep initial-element element-type)
 265       (error ":INITIAL-ELEMENT ~S is not of type ~S."
 266              initial-element element-type)))
 267   ;; STEP 2
 268   ;;
 269   ;; Allocate and possibly initialize the vector.
 270   (multiple-value-bind (type n-bits)
 271       (sb!impl::%vector-widetag-and-n-bits element-type)
 272     (let ((vector
 273            (allocate-static-vector type length
 274                                    (ceiling (* length n-bits)
 275                                             sb!vm:n-word-bits))))
 276       (cond (initial-element-p
 277              (fill vector initial-element))
 278             (initial-contents-p
 279              (replace vector initial-contents))
 280             (t
 281              vector)))))
 282
 283 ;;; DATA-VECTOR-FROM-INITS returns a simple vector that has the
 284 ;;; specified array characteristics. Dimensions is only used to pass
 285 ;;; to FILL-DATA-VECTOR for error checking on the structure of
 286 ;;; initial-contents.
 287 (defun data-vector-from-inits (dimensions total-size element-type
 288                                initial-contents initial-contents-p
 289                                initial-element initial-element-p)
 290   (when (and initial-contents-p initial-element-p)
 291     (error "cannot supply both :INITIAL-CONTENTS and :INITIAL-ELEMENT to
 292             either MAKE-ARRAY or ADJUST-ARRAY."))
 293   (let ((data (if initial-element-p
 294                   (make-array total-size
 295                               :element-type element-type
 296                               :initial-element initial-element)
 297                   (make-array total-size
 298                               :element-type element-type))))
 299     (cond (initial-element-p
 300            (unless (simple-vector-p data)
 301              (unless (typep initial-element element-type)
 302                (error "~S cannot be used to initialize an array of type ~S."
 303                       initial-element element-type))
 304              (fill (the vector data) initial-element)))
 305           (initial-contents-p
 306            (fill-data-vector data dimensions initial-contents)))
 307     data))
 308
 309 (defun vector (&rest objects)
 310   #!+sb-doc
 311   "Construct a SIMPLE-VECTOR from the given objects."
 312   (coerce (the list objects) 'simple-vector))
 313 \f
 314
 315 ;;;; accessor/setter functions
 316
 317 ;;; Dispatch to an optimized routine the data vector accessors for
 318 ;;; each different specialized vector type. Do dispatching by looking
 319 ;;; up the widetag in the array rather than with the typecases, which
 320 ;;; as of 1.0.5 compiles to a naive sequence of linear TYPEPs. Also
 321 ;;; provide separate versions where bounds checking has been moved
 322 ;;; from the callee to the caller, since it's much cheaper to do once
 323 ;;; the type information is available. Finally, for each of these
 324 ;;; routines also provide a slow path, taken for arrays that are not
 325 ;;; vectors or not simple.
 326 (macrolet ((def (name table-name)
 327              `(progn
 328                 (defvar ,table-name)
 329                 (defmacro ,name (array-var)
 330                  `(the function
 331                     (let ((tag 0)
 332                           (offset
 333                            #.(ecase sb!c:*backend-byte-order*
 334                                (:little-endian
 335                                 (- sb!vm:other-pointer-lowtag))
 336                                (:big-endian
 337                                 (- (1- sb!vm:n-word-bytes) sb!vm:other-pointer-lowtag)))))
 338                       ;; WIDETAG-OF needs extra code to handle LIST and
 339                       ;; FUNCTION lowtags. We're only dispatching on
 340                       ;; other pointers, so let's do the lowtag
 341                       ;; extraction manually.
 342                       (when (sb!vm::%other-pointer-p ,array-var)
 343                         (setf tag
 344                               (sb!sys:sap-ref-8 (int-sap (get-lisp-obj-address ,array-var))
 345                                                 offset)))
 346                       ;; SYMBOL-GLOBAL-VALUE is a performance hack
 347                       ;; for threaded builds.
 348                       (svref (sb!vm::symbol-global-value ',',table-name) tag)))))))
 349   (def !find-data-vector-setter *data-vector-setters*)
 350   (def !find-data-vector-setter/check-bounds *data-vector-setters/check-bounds*)
 351   (def !find-data-vector-reffer *data-vector-reffers*)
 352   (def !find-data-vector-reffer/check-bounds *data-vector-reffers/check-bounds*))
 353
 354 (macrolet ((%ref (accessor-getter extra-params)
 355              `(funcall (,accessor-getter array) array index ,@extra-params))
 356            (define (accessor-name slow-accessor-name accessor-getter
 357                                   extra-params check-bounds)
 358              `(progn
 359                 (defun ,accessor-name (array index ,@extra-params)
 360                   (declare (optimize speed
 361                                      ;; (SAFETY 0) is ok. All calls to
 362                                      ;; these functions are generated by
 363                                      ;; the compiler, so argument count
 364                                      ;; checking isn't needed. Type checking
 365                                      ;; is done implicitly via the widetag
 366                                      ;; dispatch.
 367                                      (safety 0)))
 368                   (%ref ,accessor-getter ,extra-params))
 369                 (defun ,slow-accessor-name (array index ,@extra-params)
 370                   (declare (optimize speed (safety 0)))
 371                   (if (not (%array-displaced-p array))
 372                       ;; The reasonably quick path of non-displaced complex
 373                       ;; arrays.
 374                       (let ((array (%array-data-vector array)))
 375                         (%ref ,accessor-getter ,extra-params))
 376                       ;; The real slow path.
 377                       (with-array-data
 378                           ((vector array)
 379                            (index (locally
 380                                       (declare (optimize (speed 1) (safety 1)))
 381                                     (,@check-bounds index)))
 382                            (end)
 383                            :force-inline t)
 384                         (declare (ignore end))
 385                         (,accessor-name vector index ,@extra-params)))))))
 386   (define hairy-data-vector-ref slow-hairy-data-vector-ref
 387     !find-data-vector-reffer
 388     nil (progn))
 389   (define hairy-data-vector-set slow-hairy-data-vector-set
 390     !find-data-vector-setter
 391     (new-value) (progn))
 392   (define hairy-data-vector-ref/check-bounds
 393       slow-hairy-data-vector-ref/check-bounds
 394     !find-data-vector-reffer/check-bounds
 395     nil (%check-bound array (array-dimension array 0)))
 396   (define hairy-data-vector-set/check-bounds
 397       slow-hairy-data-vector-set/check-bounds
 398     !find-data-vector-setter/check-bounds
 399     (new-value) (%check-bound array (array-dimension array 0))))
 400
 401 (defun hairy-ref-error (array index &optional new-value)
 402   (declare (ignore index new-value))
 403   (error 'type-error
 404          :datum array
 405          :expected-type 'vector))
 406
 407 ;;; Populate the dispatch tables.
 408 (macrolet ((define-reffer (saetp check-form)
 409              (let* ((type (sb!vm:saetp-specifier saetp))
 410                     (atype `(simple-array ,type (*))))
 411                `(named-lambda optimized-data-vector-ref (vector index)
 412                   (declare (optimize speed (safety 0)))
 413                   (data-vector-ref (the ,atype vector)
 414                                    (locally
 415                                        (declare (optimize (safety 1)))
 416                                      (the index
 417                                        (,@check-form index)))))))
 418            (define-setter (saetp check-form)
 419              (let* ((type (sb!vm:saetp-specifier saetp))
 420                     (atype `(simple-array ,type (*))))
 421                `(named-lambda optimized-data-vector-set (vector index new-value)
 422                   (declare (optimize speed (safety 0)))
 423                   (data-vector-set (the ,atype vector)
 424                                    (locally
 425                                        (declare (optimize (safety 1)))
 426                                      (the index
 427                                        (,@check-form index)))
 428                                    (locally
 429                                        ;; SPEED 1 needed to avoid the compiler
 430                                        ;; from downgrading the type check to
 431                                        ;; a cheaper one.
 432                                        (declare (optimize (speed 1)
 433                                                           (safety 1)))
 434                                      (the ,type new-value)))
 435                   ;; For specialized arrays, the return from
 436                   ;; data-vector-set would have to be reboxed to be a
 437                   ;; (Lisp) return value; instead, we use the
 438                   ;; already-boxed value as the return.
 439                   new-value)))
 440            (define-reffers (symbol deffer check-form slow-path)
 441              `(progn
 442                 (setf ,symbol (make-array sb!vm::widetag-mask
 443                                           :initial-element #'hairy-ref-error))
 444                 ,@(loop for widetag in '(sb!vm:complex-vector-widetag
 445                                          sb!vm:complex-vector-nil-widetag
 446                                          sb!vm:complex-bit-vector-widetag
 447                                          #!+sb-unicode sb!vm:complex-character-string-widetag
 448                                          sb!vm:complex-base-string-widetag
 449                                          sb!vm:simple-array-widetag
 450                                          sb!vm:complex-array-widetag)
 451                         collect `(setf (svref ,symbol ,widetag) ,slow-path))
 452                 ,@(loop for saetp across sb!vm:*specialized-array-element-type-properties*
 453                         for widetag = (sb!vm:saetp-typecode saetp)
 454                         collect `(setf (svref ,symbol ,widetag)
 455                                        (,deffer ,saetp ,check-form))))))
 456   (defun !hairy-data-vector-reffer-init ()
 457     (define-reffers *data-vector-reffers* define-reffer
 458       (progn)
 459       #'slow-hairy-data-vector-ref)
 460     (define-reffers *data-vector-setters* define-setter
 461       (progn)
 462       #'slow-hairy-data-vector-set)
 463     (define-reffers *data-vector-reffers/check-bounds* define-reffer
 464       (%check-bound vector (length vector))
 465       #'slow-hairy-data-vector-ref/check-bounds)
 466     (define-reffers *data-vector-setters/check-bounds* define-setter
 467       (%check-bound vector (length vector))
 468       #'slow-hairy-data-vector-set/check-bounds)))
 469
 470 ;;; (Ordinary DATA-VECTOR-REF usage compiles into a vop, but
 471 ;;; DATA-VECTOR-REF is also FOLDABLE, and this ordinary function
 472 ;;; definition is needed for the compiler to use in constant folding.)
 473 (defun data-vector-ref (array index)
 474   (hairy-data-vector-ref array index))
 475
 476 (defun data-vector-ref-with-offset (array index offset)
 477   (hairy-data-vector-ref array (+ index offset)))
 478
 479 ;;; SUBSCRIPTS has a dynamic-extent list structure and is destroyed
 480 (defun %array-row-major-index (array subscripts
 481                                      &optional (invalid-index-error-p t))
 482   (declare (array array)
 483            (list subscripts))
 484   (let ((rank (array-rank array)))
 485     (unless (= rank (length subscripts))
 486       (error "wrong number of subscripts, ~W, for array of rank ~W"
 487              (length subscripts) rank))
 488     (if (array-header-p array)
 489         (do ((subs (nreverse subscripts) (cdr subs))
 490              (axis (1- (array-rank array)) (1- axis))
 491              (chunk-size 1)
 492              (result 0))
 493             ((null subs) result)
 494           (declare (list subs) (fixnum axis chunk-size result))
 495           (let ((index (car subs))
 496                 (dim (%array-dimension array axis)))
 497             (declare (fixnum dim))
 498             (unless (and (fixnump index) (< -1 index dim))
 499               (if invalid-index-error-p
 500                   (error 'simple-type-error
 501                          :format-control "invalid index ~W~[~;~:; on axis ~:*~W~] in ~S"
 502                          :format-arguments (list index axis array)
 503                          :datum index
 504                          :expected-type `(integer 0 (,dim)))
 505                   (return-from %array-row-major-index nil)))
 506             (incf result (* chunk-size (the fixnum index)))
 507             (setf chunk-size (* chunk-size dim))))
 508         (let ((index (first subscripts))
 509               (length (length (the (simple-array * (*)) array))))
 510           (unless (and (fixnump index) (< -1 index length))
 511             (if invalid-index-error-p
 512                 ;; FIXME: perhaps this should share a format-string
 513                 ;; with INVALID-ARRAY-INDEX-ERROR or
 514                 ;; INDEX-TOO-LARGE-ERROR?
 515                 (error 'simple-type-error
 516                        :format-control "invalid index ~W in ~S"
 517                        :format-arguments (list index array)
 518                        :datum index
 519                        :expected-type `(integer 0 (,length)))
 520                 (return-from %array-row-major-index nil)))
 521           index))))
 522
 523 (defun array-in-bounds-p (array &rest subscripts)
 524   #!+sb-doc
 525   "Return T if the SUBSCIPTS are in bounds for the ARRAY, NIL otherwise."
 526   (if (%array-row-major-index array subscripts nil)
 527       t))
 528
 529 (defun array-row-major-index (array &rest subscripts)
 530   (declare (truly-dynamic-extent subscripts))
 531   (%array-row-major-index array subscripts))
 532
 533 (defun aref (array &rest subscripts)
 534   #!+sb-doc
 535   "Return the element of the ARRAY specified by the SUBSCRIPTS."
 536   (declare (truly-dynamic-extent subscripts))
 537   (row-major-aref array (%array-row-major-index array subscripts)))
 538
 539 (defun %aset (array &rest stuff)
 540   (declare (truly-dynamic-extent stuff))
 541   (let ((subscripts (butlast stuff))
 542         (new-value (car (last stuff))))
 543     (setf (row-major-aref array (%array-row-major-index array subscripts))
 544           new-value)))
 545
 546 ;;; FIXME: What's supposed to happen with functions
 547 ;;; like AREF when we (DEFUN (SETF FOO) ..) when
 548 ;;; DEFSETF FOO is also defined? It seems as though the logical
 549 ;;; thing to do would be to nuke the macro definition for (SETF FOO)
 550 ;;; and replace it with the (SETF FOO) function, issuing a warning,
 551 ;;; just as for ordinary functions
 552 ;;;  * (LISP-IMPLEMENTATION-VERSION)
 553 ;;;  "18a+ release x86-linux 2.4.7 6 November 1998 cvs"
 554 ;;;  * (DEFMACRO ZOO (X) `(+ ,X ,X))
 555 ;;;  ZOO
 556 ;;;  * (DEFUN ZOO (X) (* 3 X))
 557 ;;;  Warning: ZOO previously defined as a macro.
 558 ;;;  ZOO
 559 ;;; But that doesn't seem to be what happens in CMU CL.
 560 ;;;
 561 ;;; KLUDGE: this is probably because ANSI, in its wisdom (CLHS
 562 ;;; 5.1.2.5) requires implementations to support
 563 ;;;   (SETF (APPLY #'AREF ...) ...)
 564 ;;; [and also #'BIT and #'SBIT].  Yes, this is terrifying, and it's
 565 ;;; also terrifying that this sequence of definitions causes it to
 566 ;;; work.
 567 ;;;
 568 ;;; Also, it would be nice to make DESCRIBE FOO tell whether a symbol
 569 ;;; has a setf expansion and/or a setf function defined.
 570
 571 #!-sb-fluid (declaim (inline (setf aref)))
 572 (defun (setf aref) (new-value array &rest subscripts)
 573   (declare (truly-dynamic-extent subscripts))
 574   (declare (type array array))
 575   (setf (row-major-aref array (%array-row-major-index array subscripts))
 576         new-value))
 577
 578 (defun row-major-aref (array index)
 579   #!+sb-doc
 580   "Return the element of array corressponding to the row-major index. This is
 581    SETF'able."
 582   (declare (optimize (safety 1)))
 583   (row-major-aref array index))
 584
 585 (defun %set-row-major-aref (array index new-value)
 586   (declare (optimize (safety 1)))
 587   (setf (row-major-aref array index) new-value))
 588
 589 (defun svref (simple-vector index)
 590   #!+sb-doc
 591   "Return the INDEX'th element of the given Simple-Vector."
 592   (declare (optimize (safety 1)))
 593   (aref simple-vector index))
 594
 595 (defun %svset (simple-vector index new)
 596   (declare (optimize (safety 1)))
 597   (setf (aref simple-vector index) new))
 598
 599 (defun bit (bit-array &rest subscripts)
 600   #!+sb-doc
 601   "Return the bit from the BIT-ARRAY at the specified SUBSCRIPTS."
 602   (declare (type (array bit) bit-array) (optimize (safety 1)))
 603   (row-major-aref bit-array (%array-row-major-index bit-array subscripts)))
 604
 605 (defun %bitset (bit-array &rest stuff)
 606   (declare (type (array bit) bit-array) (optimize (safety 1)))
 607   (let ((subscripts (butlast stuff))
 608         (new-value (car (last stuff))))
 609     (setf (row-major-aref bit-array
 610                           (%array-row-major-index bit-array subscripts))
 611           new-value)))
 612
 613 #!-sb-fluid (declaim (inline (setf bit)))
 614 (defun (setf bit) (new-value bit-array &rest subscripts)
 615   (declare (type (array bit) bit-array) (optimize (safety 1)))
 616   (setf (row-major-aref bit-array
 617                         (%array-row-major-index bit-array subscripts))
 618         new-value))
 619
 620 (defun sbit (simple-bit-array &rest subscripts)
 621   #!+sb-doc
 622   "Return the bit from SIMPLE-BIT-ARRAY at the specified SUBSCRIPTS."
 623   (declare (type (simple-array bit) simple-bit-array) (optimize (safety 1)))
 624   (row-major-aref simple-bit-array
 625                   (%array-row-major-index simple-bit-array subscripts)))
 626
 627 ;;; KLUDGE: Not all these things (%SET-ROW-MAJOR-AREF, %SET-FILL-POINTER,
 628 ;;; %SET-FDEFINITION, %SCHARSET, %SBITSET..) seem to deserve separate names.
 629 ;;; Could we just DEFUN (SETF SBIT) etc. and get rid of the non-ANSI names?
 630 ;;; -- WHN 19990911
 631 (defun %sbitset (simple-bit-array &rest stuff)
 632   (declare (type (simple-array bit) simple-bit-array) (optimize (safety 1)))
 633   (let ((subscripts (butlast stuff))
 634         (new-value (car (last stuff))))
 635     (setf (row-major-aref simple-bit-array
 636                           (%array-row-major-index simple-bit-array subscripts))
 637           new-value)))
 638
 639 #!-sb-fluid (declaim (inline (setf sbit)))
 640 (defun (setf sbit) (new-value bit-array &rest subscripts)
 641   (declare (type (simple-array bit) bit-array) (optimize (safety 1)))
 642   (setf (row-major-aref bit-array
 643                         (%array-row-major-index bit-array subscripts))
 644         new-value))
 645 \f
 646 ;;;; miscellaneous array properties
 647
 648 (defun array-element-type (array)
 649   #!+sb-doc
 650   "Return the type of the elements of the array"
 651   (let ((widetag (widetag-of array)))
 652     (macrolet ((pick-element-type (&rest stuff)
 653                  `(cond ,@(mapcar (lambda (stuff)
 654                                     (cons
 655                                      (let ((item (car stuff)))
 656                                        (cond ((eq item t)
 657                                               t)
 658                                              ((listp item)
 659                                               (cons 'or
 660                                                     (mapcar (lambda (x)
 661                                                               `(= widetag ,x))
 662                                                             item)))
 663                                              (t
 664                                               `(= widetag ,item))))
 665                                      (cdr stuff)))
 666                                   stuff))))
 667       #.`(pick-element-type
 668           ,@(map 'list
 669                  (lambda (saetp)
 670                    `(,(if (sb!vm:saetp-complex-typecode saetp)
 671                           (list (sb!vm:saetp-typecode saetp)
 672                                 (sb!vm:saetp-complex-typecode saetp))
 673                           (sb!vm:saetp-typecode saetp))
 674                      ',(sb!vm:saetp-specifier saetp)))
 675                  sb!vm:*specialized-array-element-type-properties*)
 676           ((sb!vm:simple-array-widetag
 677             sb!vm:complex-vector-widetag
 678             sb!vm:complex-array-widetag)
 679            (with-array-data ((array array) (start) (end))
 680              (declare (ignore start end))
 681              (array-element-type array)))
 682           (t
 683            (error 'type-error :datum array :expected-type 'array))))))
 684
 685 (defun array-rank (array)
 686   #!+sb-doc
 687   "Return the number of dimensions of ARRAY."
 688   (if (array-header-p array)
 689       (%array-rank array)
 690       1))
 691
 692 (defun array-dimension (array axis-number)
 693   #!+sb-doc
 694   "Return the length of dimension AXIS-NUMBER of ARRAY."
 695   (declare (array array) (type index axis-number))
 696   (cond ((not (array-header-p array))
 697          (unless (= axis-number 0)
 698            (error "Vector axis is not zero: ~S" axis-number))
 699          (length (the (simple-array * (*)) array)))
 700         ((>= axis-number (%array-rank array))
 701          (error "Axis number ~W is too big; ~S only has ~D dimension~:P."
 702                 axis-number array (%array-rank array)))
 703         (t
 704          ;; ANSI sayeth (ADJUST-ARRAY dictionary entry):
 705          ;;
 706          ;;   "If A is displaced to B, the consequences are
 707          ;;   unspecified if B is adjusted in such a way that it no
 708          ;;   longer has enough elements to satisfy A.
 709          ;;
 710          ;; In situations where this matters we should be doing a
 711          ;; bounds-check, which in turn uses ARRAY-DIMENSION -- so
 712          ;; this seems like a good place to signal an error.
 713          (multiple-value-bind (target offset) (array-displacement array)
 714            (when (and target
 715                       (> (array-total-size array)
 716                          (- (array-total-size target) offset)))
 717                (error 'displaced-to-array-too-small-error
 718                       :format-control "~@<The displaced-to array is too small. ~S ~
 719                                       elements after offset required, ~S available.~:@>"
 720                       :format-arguments (list (array-total-size array)
 721                                               (- (array-total-size target) offset))))
 722            (%array-dimension array axis-number)))))
 723
 724 (defun array-dimensions (array)
 725   #!+sb-doc
 726   "Return a list whose elements are the dimensions of the array"
 727   (declare (array array))
 728   (if (array-header-p array)
 729       (do ((results nil (cons (array-dimension array index) results))
 730            (index (1- (array-rank array)) (1- index)))
 731           ((minusp index) results))
 732       (list (array-dimension array 0))))
 733
 734 (defun array-total-size (array)
 735   #!+sb-doc
 736   "Return the total number of elements in the Array."
 737   (declare (array array))
 738   (if (array-header-p array)
 739       (%array-available-elements array)
 740       (length (the vector array))))
 741
 742 (defun array-displacement (array)
 743   #!+sb-doc
 744   "Return the values of :DISPLACED-TO and :DISPLACED-INDEX-offset
 745    options to MAKE-ARRAY, or NIL and 0 if not a displaced array."
 746   (declare (type array array))
 747   (if (and (array-header-p array) ; if unsimple and
 748            (%array-displaced-p array)) ; displaced
 749       (values (%array-data-vector array) (%array-displacement array))
 750       (values nil 0)))
 751
 752 (defun adjustable-array-p (array)
 753   #!+sb-doc
 754   "Return T if (ADJUST-ARRAY ARRAY...) would return an array identical
 755    to the argument, this happens for complex arrays."
 756   (declare (array array))
 757   ;; Note that this appears not to be a fundamental limitation.
 758   ;; non-vector SIMPLE-ARRAYs are in fact capable of being adjusted,
 759   ;; but in practice we test using ADJUSTABLE-ARRAY-P in ADJUST-ARRAY.
 760   ;; -- CSR, 2004-03-01.
 761   (not (typep array 'simple-array)))
 762 \f
 763 ;;;; fill pointer frobbing stuff
 764
 765 (defun array-has-fill-pointer-p (array)
 766   #!+sb-doc
 767   "Return T if the given ARRAY has a fill pointer, or NIL otherwise."
 768   (declare (array array))
 769   (and (array-header-p array) (%array-fill-pointer-p array)))
 770
 771 (defun fill-pointer-error (vector arg)
 772   (cond (arg
 773          (aver (array-has-fill-pointer-p vector))
 774          (let ((max (%array-available-elements vector)))
 775            (error 'simple-type-error
 776                   :datum arg
 777                   :expected-type (list 'integer 0 max)
 778                   :format-control "The new fill pointer, ~S, is larger than the length of the vector (~S.)"
 779                   arg max)))
 780         (t
 781          (error 'simple-type-error
 782                 :datum vector
 783                 :expected-type '(and vector (satisfies array-has-fill-pointer-p))
 784                 :format-control "~S is not an array with a fill pointer."
 785                 :format-arguments (list vector)))))
 786
 787 (defun fill-pointer (vector)
 788   #!+sb-doc
 789   "Return the FILL-POINTER of the given VECTOR."
 790   (if (array-has-fill-pointer-p vector)
 791       (%array-fill-pointer vector)
 792       (fill-pointer-error vector nil)))
 793
 794 (defun %set-fill-pointer (vector new)
 795   (flet ((oops (x)
 796            (fill-pointer-error vector x)))
 797     (if (array-has-fill-pointer-p vector)
 798         (if (> new (%array-available-elements vector))
 799             (oops new)
 800             (setf (%array-fill-pointer vector) new))
 801         (oops nil))))
 802
 803 ;;; FIXME: It'd probably make sense to use a MACROLET to share the
 804 ;;; guts of VECTOR-PUSH between VECTOR-PUSH-EXTEND. Such a macro
 805 ;;; should probably be based on the VECTOR-PUSH-EXTEND code (which is
 806 ;;; new ca. sbcl-0.7.0) rather than the VECTOR-PUSH code (which dates
 807 ;;; back to CMU CL).
 808 (defun vector-push (new-el array)
 809   #!+sb-doc
 810   "Attempt to set the element of ARRAY designated by its fill pointer
 811    to NEW-EL, and increment the fill pointer by one. If the fill pointer is
 812    too large, NIL is returned, otherwise the index of the pushed element is
 813    returned."
 814   (declare (vector array))
 815   (let ((fill-pointer (fill-pointer array)))
 816     (declare (fixnum fill-pointer))
 817     (cond ((= fill-pointer (%array-available-elements array))
 818            nil)
 819           (t
 820            (locally (declare (optimize (safety 0)))
 821              (setf (aref array fill-pointer) new-el))
 822            (setf (%array-fill-pointer array) (1+ fill-pointer))
 823            fill-pointer))))
 824
 825 (defun vector-push-extend (new-element
 826                            vector
 827                            &optional
 828                            (min-extension
 829                             (let ((length (length vector)))
 830                               (min (1+ length)
 831                                    (- array-dimension-limit length)))))
 832   (declare (vector vector) (fixnum min-extension))
 833   (let ((fill-pointer (fill-pointer vector)))
 834     (declare (fixnum fill-pointer))
 835     (when (= fill-pointer (%array-available-elements vector))
 836       (adjust-array vector (+ fill-pointer (max 1 min-extension))))
 837     ;; disable bounds checking
 838     (locally (declare (optimize (safety 0)))
 839       (setf (aref vector fill-pointer) new-element))
 840     (setf (%array-fill-pointer vector) (1+ fill-pointer))
 841     fill-pointer))
 842
 843 (defun vector-pop (array)
 844   #!+sb-doc
 845   "Decrease the fill pointer by 1 and return the element pointed to by the
 846   new fill pointer."
 847   (declare (vector array))
 848   (let ((fill-pointer (fill-pointer array)))
 849     (declare (fixnum fill-pointer))
 850     (if (zerop fill-pointer)
 851         (error "There is nothing left to pop.")
 852         ;; disable bounds checking (and any fixnum test)
 853         (locally (declare (optimize (safety 0)))
 854           (aref array
 855                 (setf (%array-fill-pointer array)
 856                       (1- fill-pointer)))))))
 857
 858 \f
 859 ;;;; ADJUST-ARRAY
 860
 861 (defun adjust-array (array dimensions &key
 862                            (element-type (array-element-type array))
 863                            (initial-element nil initial-element-p)
 864                            (initial-contents nil initial-contents-p)
 865                            fill-pointer
 866                            displaced-to displaced-index-offset)
 867   #!+sb-doc
 868   "Adjust ARRAY's dimensions to the given DIMENSIONS and stuff."
 869   (let ((dimensions (if (listp dimensions) dimensions (list dimensions))))
 870     (cond ((/= (the fixnum (length (the list dimensions)))
 871                (the fixnum (array-rank array)))
 872            (error "The number of dimensions not equal to rank of array."))
 873           ((not (subtypep element-type (array-element-type array)))
 874            (error "The new element type, ~S, is incompatible with old type."
 875                   element-type))
 876           ((and fill-pointer (not (array-has-fill-pointer-p array)))
 877            (error 'type-error
 878                   :datum array
 879                   :expected-type '(satisfies array-has-fill-pointer-p))))
 880     (let ((array-rank (length (the list dimensions))))
 881       (declare (fixnum array-rank))
 882       (unless (= array-rank 1)
 883         (when fill-pointer
 884           (error "Only vectors can have fill pointers.")))
 885       (cond (initial-contents-p
 886              ;; array former contents replaced by INITIAL-CONTENTS
 887              (if (or initial-element-p displaced-to)
 888                  (error "INITIAL-CONTENTS may not be specified with ~
 889                          the :INITIAL-ELEMENT or :DISPLACED-TO option."))
 890              (let* ((array-size (apply #'* dimensions))
 891                     (array-data (data-vector-from-inits
 892                                  dimensions array-size element-type
 893                                  initial-contents initial-contents-p
 894                                  initial-element initial-element-p)))
 895                (if (adjustable-array-p array)
 896                    (set-array-header array array-data array-size
 897                                  (get-new-fill-pointer array array-size
 898                                                        fill-pointer)
 899                                  0 dimensions nil)
 900                    (if (array-header-p array)
 901                        ;; simple multidimensional or single dimensional array
 902                        (make-array dimensions
 903                                    :element-type element-type
 904                                    :initial-contents initial-contents)
 905                        array-data))))
 906             (displaced-to
 907              ;; We already established that no INITIAL-CONTENTS was supplied.
 908              (when initial-element
 909                (error "The :INITIAL-ELEMENT option may not be specified ~
 910                        with :DISPLACED-TO."))
 911              (unless (subtypep element-type (array-element-type displaced-to))
 912                (error "can't displace an array of type ~S into another of ~
 913                        type ~S"
 914                       element-type (array-element-type displaced-to)))
 915              (let ((displacement (or displaced-index-offset 0))
 916                    (array-size (apply #'* dimensions)))
 917                (declare (fixnum displacement array-size))
 918                (if (< (the fixnum (array-total-size displaced-to))
 919                       (the fixnum (+ displacement array-size)))
 920                    (error "The :DISPLACED-TO array is too small."))
 921                (if (adjustable-array-p array)
 922                    ;; None of the original contents appear in adjusted array.
 923                    (set-array-header array displaced-to array-size
 924                                      (get-new-fill-pointer array array-size
 925                                                            fill-pointer)
 926                                      displacement dimensions t)
 927                    ;; simple multidimensional or single dimensional array
 928                    (make-array dimensions
 929                                :element-type element-type
 930                                :displaced-to displaced-to
 931                                :displaced-index-offset
 932                                displaced-index-offset))))
 933             ((= array-rank 1)
 934              (let ((old-length (array-total-size array))
 935                    (new-length (car dimensions))
 936                    new-data)
 937                (declare (fixnum old-length new-length))
 938                (with-array-data ((old-data array) (old-start)
 939                                  (old-end old-length))
 940                  (cond ((or (and (array-header-p array)
 941                                  (%array-displaced-p array))
 942                             (< old-length new-length))
 943                         (setf new-data
 944                               (data-vector-from-inits
 945                                dimensions new-length element-type
 946                                initial-contents initial-contents-p
 947                                initial-element initial-element-p))
 948                         (replace new-data old-data
 949                                  :start2 old-start :end2 old-end))
 950                        (t (setf new-data
 951                                 (shrink-vector old-data new-length))))
 952                  (if (adjustable-array-p array)
 953                      (set-array-header array new-data new-length
 954                                        (get-new-fill-pointer array new-length
 955                                                              fill-pointer)
 956                                        0 dimensions nil)
 957                      new-data))))
 958             (t
 959              (let ((old-length (%array-available-elements array))
 960                    (new-length (apply #'* dimensions)))
 961                (declare (fixnum old-length new-length))
 962                (with-array-data ((old-data array) (old-start)
 963                                  (old-end old-length))
 964                  (declare (ignore old-end))
 965                  (let ((new-data (if (or (and (array-header-p array)
 966                                               (%array-displaced-p array))
 967                                          (> new-length old-length))
 968                                      (data-vector-from-inits
 969                                       dimensions new-length
 970                                       element-type () nil
 971                                       initial-element initial-element-p)
 972                                      old-data)))
 973                    (if (or (zerop old-length) (zerop new-length))
 974                        (when initial-element-p (fill new-data initial-element))
 975                        (zap-array-data old-data (array-dimensions array)
 976                                        old-start
 977                                        new-data dimensions new-length
 978                                        element-type initial-element
 979                                        initial-element-p))
 980                    (if (adjustable-array-p array)
 981                        (set-array-header array new-data new-length
 982                                          nil 0 dimensions nil)
 983                        (let ((new-array
 984                               (make-array-header
 985                                sb!vm:simple-array-widetag array-rank)))
 986                          (set-array-header new-array new-data new-length
 987                                            nil 0 dimensions nil)))))))))))
 988
 989
 990 (defun get-new-fill-pointer (old-array new-array-size fill-pointer)
 991   (cond ((not fill-pointer)
 992          (when (array-has-fill-pointer-p old-array)
 993            (when (> (%array-fill-pointer old-array) new-array-size)
 994              (error "cannot ADJUST-ARRAY an array (~S) to a size (~S) that is ~
 995                      smaller than its fill pointer (~S)"
 996                     old-array new-array-size (fill-pointer old-array)))
 997            (%array-fill-pointer old-array)))
 998         ((not (array-has-fill-pointer-p old-array))
 999          (error "cannot supply a non-NIL value (~S) for :FILL-POINTER ~
1000                  in ADJUST-ARRAY unless the array (~S) was originally ~
1001                  created with a fill pointer"
1002                 fill-pointer
1003                 old-array))
1004         ((numberp fill-pointer)
1005          (when (> fill-pointer new-array-size)
1006            (error "can't supply a value for :FILL-POINTER (~S) that is larger ~
1007                    than the new length of the vector (~S)"
1008                   fill-pointer new-array-size))
1009          fill-pointer)
1010         ((eq fill-pointer t)
1011          new-array-size)
1012         (t
1013          (error "bogus value for :FILL-POINTER in ADJUST-ARRAY: ~S"
1014                 fill-pointer))))
1015
1016 ;;; Destructively alter VECTOR, changing its length to NEW-LENGTH,
1017 ;;; which must be less than or equal to its current length. This can
1018 ;;; be called on vectors without a fill pointer but it is extremely
1019 ;;; dangerous to do so: shrinking the size of an object (as viewed by
1020 ;;; the gc) makes bounds checking unreliable in the face of interrupts
1021 ;;; or multi-threading. Call it only on provably local vectors.
1022 (defun %shrink-vector (vector new-length)
1023   (declare (vector vector))
1024   (unless (array-header-p vector)
1025     (macrolet ((frob (name &rest things)
1026                  `(etypecase ,name
1027                     ((simple-array nil (*)) (error 'nil-array-accessed-error))
1028                     ,@(mapcar (lambda (thing)
1029                                 (destructuring-bind (type-spec fill-value)
1030                                     thing
1031                                   `(,type-spec
1032                                     (fill (truly-the ,type-spec ,name)
1033                                           ,fill-value
1034                                           :start new-length))))
1035                               things))))
1036       ;; Set the 'tail' of the vector to the appropriate type of zero,
1037       ;; "because in some cases we'll scavenge larger areas in one go,
1038       ;; like groups of pages that had triggered the write barrier, or
1039       ;; the whole static space" according to jsnell.
1040       #.`(frob vector
1041           ,@(map 'list
1042                  (lambda (saetp)
1043                    `((simple-array ,(sb!vm:saetp-specifier saetp) (*))
1044                      ,(if (or (eq (sb!vm:saetp-specifier saetp) 'character)
1045                               #!+sb-unicode
1046                               (eq (sb!vm:saetp-specifier saetp) 'base-char))
1047                           *default-init-char-form*
1048                           (sb!vm:saetp-initial-element-default saetp))))
1049                  (remove-if-not
1050                   #'sb!vm:saetp-specifier
1051                   sb!vm:*specialized-array-element-type-properties*)))))
1052   ;; Only arrays have fill-pointers, but vectors have their length
1053   ;; parameter in the same place.
1054   (setf (%array-fill-pointer vector) new-length)
1055   vector)
1056
1057 (defun shrink-vector (vector new-length)
1058   (declare (vector vector))
1059   (cond
1060     ((eq (length vector) new-length)
1061      vector)
1062     ((array-has-fill-pointer-p vector)
1063      (setf (%array-fill-pointer vector) new-length)
1064      vector)
1065     (t (subseq vector 0 new-length))))
1066
1067 ;;; Fill in array header with the provided information, and return the array.
1068 (defun set-array-header (array data length fill-pointer displacement dimensions
1069                          &optional displacedp)
1070   (setf (%array-data-vector array) data)
1071   (setf (%array-available-elements array) length)
1072   (cond (fill-pointer
1073          (setf (%array-fill-pointer array) fill-pointer)
1074          (setf (%array-fill-pointer-p array) t))
1075         (t
1076          (setf (%array-fill-pointer array) length)
1077          (setf (%array-fill-pointer-p array) nil)))
1078   (setf (%array-displacement array) displacement)
1079   (if (listp dimensions)
1080       (dotimes (axis (array-rank array))
1081         (declare (type index axis))
1082         (setf (%array-dimension array axis) (pop dimensions)))
1083       (setf (%array-dimension array 0) dimensions))
1084   (setf (%array-displaced-p array) displacedp)
1085   array)
1086 \f
1087 ;;;; used by SORT
1088
1089 ;;; temporary vector for stable sorting vectors, allocated for each new thread
1090 (defvar *merge-sort-temp-vector* (vector))
1091 (declaim (simple-vector *merge-sort-temp-vector*))
1092
1093 ;;;; ZAP-ARRAY-DATA for ADJUST-ARRAY
1094
1095 ;;; a temporary to be used when OLD-DATA and NEW-DATA are EQ.
1096 ;;; KLUDGE: Boy, DYNAMIC-EXTENT would be nice. This is rebound
1097 ;;; to length zero array in each new thread.
1098 ;;;
1099 ;;; DX is probably a bad idea, because a with a big array it would
1100 ;;; be fairly easy to blow the stack.
1101 (defvar *zap-array-data-temp* (vector))
1102 (declaim (simple-vector *zap-array-data-temp*))
1103
1104 (defun zap-array-data-temp (length initial-element initial-element-p)
1105   (declare (fixnum length))
1106   (let ((tmp *zap-array-data-temp*))
1107     (declare (simple-vector tmp))
1108     (cond ((> length (length tmp))
1109            (setf *zap-array-data-temp*
1110                  (if initial-element-p
1111                      (make-array length :initial-element initial-element)
1112                      (make-array length))))
1113           (initial-element-p
1114            (fill tmp initial-element :end length))
1115           (t
1116            tmp))))
1117
1118 ;;; This does the grinding work for ADJUST-ARRAY. It zaps the data
1119 ;;; from the OLD-DATA in an arrangement specified by the OLD-DIMS to
1120 ;;; the NEW-DATA in an arrangement specified by the NEW-DIMS. OFFSET
1121 ;;; is a displaced offset to be added to computed indices of OLD-DATA.
1122 (defun zap-array-data (old-data old-dims offset new-data new-dims new-length
1123                        element-type initial-element initial-element-p)
1124   (declare (list old-dims new-dims))
1125   ;; OLD-DIMS comes from array-dimensions, which returns a fresh list
1126   ;; at least in SBCL.
1127   ;; NEW-DIMS comes from the user.
1128   (setf old-dims (nreverse old-dims)
1129         new-dims (reverse new-dims))
1130   (cond ((eq old-data new-data)
1131          ;; NEW-LENGTH, ELEMENT-TYPE, INITIAL-ELEMENT, and
1132          ;; INITIAL-ELEMENT-P are used when OLD-DATA and NEW-DATA are
1133          ;; EQ; in this case, a temporary must be used and filled
1134          ;; appropriately. specified initial-element.
1135          (when initial-element-p
1136            ;; FIXME: transforming this TYPEP to someting a bit faster
1137            ;; would be a win...
1138            (unless (typep initial-element element-type)
1139              (error "~S can't be used to initialize an array of type ~S."
1140                     initial-element element-type)))
1141          (let ((temp (zap-array-data-temp new-length
1142                                           initial-element initial-element-p)))
1143            (declare (simple-vector temp))
1144            (zap-array-data-aux old-data old-dims offset temp new-dims)
1145            (dotimes (i new-length)
1146              (setf (aref new-data i) (aref temp i)
1147                    ;; zero out any garbage right away
1148                    (aref temp i) 0))))
1149         (t
1150          ;; When OLD-DATA and NEW-DATA are not EQ, NEW-DATA has
1151          ;; already been filled with any
1152          (zap-array-data-aux old-data old-dims offset new-data new-dims))))
1153
1154 (defun zap-array-data-aux (old-data old-dims offset new-data new-dims)
1155   (declare (fixnum offset))
1156   (let ((limits (mapcar (lambda (x y)
1157                           (declare (fixnum x y))
1158                           (1- (the fixnum (min x y))))
1159                         old-dims new-dims)))
1160     (macrolet ((bump-index-list (index limits)
1161                  `(do ((subscripts ,index (cdr subscripts))
1162                        (limits ,limits (cdr limits)))
1163                       ((null subscripts) :eof)
1164                     (cond ((< (the fixnum (car subscripts))
1165                               (the fixnum (car limits)))
1166                            (rplaca subscripts
1167                                    (1+ (the fixnum (car subscripts))))
1168                            (return ,index))
1169                           (t (rplaca subscripts 0))))))
1170       (do ((index (make-list (length old-dims) :initial-element 0)
1171                   (bump-index-list index limits)))
1172           ((eq index :eof))
1173         (setf (aref new-data (row-major-index-from-dims index new-dims))
1174               (aref old-data
1175                     (+ (the fixnum (row-major-index-from-dims index old-dims))
1176                        offset)))))))
1177
1178 ;;; Figure out the row-major-order index of an array reference from a
1179 ;;; list of subscripts and a list of dimensions. This is for internal
1180 ;;; calls only, and the subscripts and dim-list variables are assumed
1181 ;;; to be reversed from what the user supplied.
1182 (defun row-major-index-from-dims (rev-subscripts rev-dim-list)
1183   (do ((rev-subscripts rev-subscripts (cdr rev-subscripts))
1184        (rev-dim-list rev-dim-list (cdr rev-dim-list))
1185        (chunk-size 1)
1186        (result 0))
1187       ((null rev-dim-list) result)
1188     (declare (fixnum chunk-size result))
1189     (setq result (+ result
1190                     (the fixnum (* (the fixnum (car rev-subscripts))
1191                                    chunk-size))))
1192     (setq chunk-size (* chunk-size (the fixnum (car rev-dim-list))))))
1193 \f
1194 ;;;; some bit stuff
1195
1196 (defun bit-array-same-dimensions-p (array1 array2)
1197   (declare (type (array bit) array1 array2))
1198   (and (= (array-rank array1)
1199           (array-rank array2))
1200        (dotimes (index (array-rank array1) t)
1201          (when (/= (array-dimension array1 index)
1202                    (array-dimension array2 index))
1203            (return nil)))))
1204
1205 (defun pick-result-array (result-bit-array bit-array-1)
1206   (case result-bit-array
1207     ((t) bit-array-1)
1208     ((nil) (make-array (array-dimensions bit-array-1)
1209                        :element-type 'bit
1210                        :initial-element 0))
1211     (t
1212      (unless (bit-array-same-dimensions-p bit-array-1
1213                                           result-bit-array)
1214        (error "~S and ~S don't have the same dimensions."
1215               bit-array-1 result-bit-array))
1216      result-bit-array)))
1217
1218 (defmacro def-bit-array-op (name function)
1219   `(defun ,name (bit-array-1 bit-array-2 &optional result-bit-array)
1220      #!+sb-doc
1221      ,(format nil
1222               "Perform a bit-wise ~A on the elements of BIT-ARRAY-1 and ~
1223                BIT-ARRAY-2,~%  putting the results in RESULT-BIT-ARRAY. ~
1224                If RESULT-BIT-ARRAY is T,~%  BIT-ARRAY-1 is used. If ~
1225                RESULT-BIT-ARRAY is NIL or omitted, a new array is~%  created. ~
1226                All the arrays must have the same rank and dimensions."
1227               (symbol-name function))
1228      (declare (type (array bit) bit-array-1 bit-array-2)
1229               (type (or (array bit) (member t nil)) result-bit-array))
1230      (unless (bit-array-same-dimensions-p bit-array-1 bit-array-2)
1231        (error "~S and ~S don't have the same dimensions."
1232               bit-array-1 bit-array-2))
1233      (let ((result-bit-array (pick-result-array result-bit-array bit-array-1)))
1234        (if (and (simple-bit-vector-p bit-array-1)
1235                 (simple-bit-vector-p bit-array-2)
1236                 (simple-bit-vector-p result-bit-array))
1237            (locally (declare (optimize (speed 3) (safety 0)))
1238              (,name bit-array-1 bit-array-2 result-bit-array))
1239            (with-array-data ((data1 bit-array-1) (start1) (end1))
1240              (declare (ignore end1))
1241              (with-array-data ((data2 bit-array-2) (start2) (end2))
1242                (declare (ignore end2))
1243                (with-array-data ((data3 result-bit-array) (start3) (end3))
1244                  (do ((index-1 start1 (1+ index-1))
1245                       (index-2 start2 (1+ index-2))
1246                       (index-3 start3 (1+ index-3)))
1247                      ((>= index-3 end3) result-bit-array)
1248                    (declare (type index index-1 index-2 index-3))
1249                    (setf (sbit data3 index-3)
1250                          (logand (,function (sbit data1 index-1)
1251                                             (sbit data2 index-2))
1252                                  1))))))))))
1253
1254 (def-bit-array-op bit-and logand)
1255 (def-bit-array-op bit-ior logior)
1256 (def-bit-array-op bit-xor logxor)
1257 (def-bit-array-op bit-eqv logeqv)
1258 (def-bit-array-op bit-nand lognand)
1259 (def-bit-array-op bit-nor lognor)
1260 (def-bit-array-op bit-andc1 logandc1)
1261 (def-bit-array-op bit-andc2 logandc2)
1262 (def-bit-array-op bit-orc1 logorc1)
1263 (def-bit-array-op bit-orc2 logorc2)
1264
1265 (defun bit-not (bit-array &optional result-bit-array)
1266   #!+sb-doc
1267   "Performs a bit-wise logical NOT on the elements of BIT-ARRAY,
1268   putting the results in RESULT-BIT-ARRAY. If RESULT-BIT-ARRAY is T,
1269   BIT-ARRAY is used. If RESULT-BIT-ARRAY is NIL or omitted, a new array is
1270   created. Both arrays must have the same rank and dimensions."
1271   (declare (type (array bit) bit-array)
1272            (type (or (array bit) (member t nil)) result-bit-array))
1273   (let ((result-bit-array (pick-result-array result-bit-array bit-array)))
1274     (if (and (simple-bit-vector-p bit-array)
1275              (simple-bit-vector-p result-bit-array))
1276         (locally (declare (optimize (speed 3) (safety 0)))
1277           (bit-not bit-array result-bit-array))
1278         (with-array-data ((src bit-array) (src-start) (src-end))
1279           (declare (ignore src-end))
1280           (with-array-data ((dst result-bit-array) (dst-start) (dst-end))
1281             (do ((src-index src-start (1+ src-index))
1282                  (dst-index dst-start (1+ dst-index)))
1283                 ((>= dst-index dst-end) result-bit-array)
1284               (declare (type index src-index dst-index))
1285               (setf (sbit dst dst-index)
1286                     (logxor (sbit src src-index) 1))))))))