src/compiler/array-tran.lisp

   1 ;;;; array-specific optimizers and transforms
   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!C")
  13 \f
  14 ;;;; utilities for optimizing array operations
  15
  16 ;;; Return UPGRADED-ARRAY-ELEMENT-TYPE for LVAR, or do
  17 ;;; GIVE-UP-IR1-TRANSFORM if the upgraded element type can't be
  18 ;;; determined.
  19 (defun upgraded-element-type-specifier-or-give-up (lvar)
  20   (let ((element-type-specifier (upgraded-element-type-specifier lvar)))
  21     (if (eq element-type-specifier '*)
  22         (give-up-ir1-transform
  23          "upgraded array element type not known at compile time")
  24         element-type-specifier)))
  25
  26 (defun upgraded-element-type-specifier (lvar)
  27   (type-specifier (array-type-upgraded-element-type (lvar-type lvar))))
  28
  29 ;;; Array access functions return an object from the array, hence its type is
  30 ;;; going to be the array upgraded element type. Secondary return value is the
  31 ;;; known supertype of the upgraded-array-element-type, if if the exact
  32 ;;; U-A-E-T is not known. (If it is NIL, the primary return value is as good
  33 ;;; as it gets.)
  34 (defun array-type-upgraded-element-type (type)
  35   (typecase type
  36     ;; Note that this IF mightn't be satisfied even if the runtime
  37     ;; value is known to be a subtype of some specialized ARRAY, because
  38     ;; we can have values declared e.g. (AND SIMPLE-VECTOR UNKNOWN-TYPE),
  39     ;; which are represented in the compiler as INTERSECTION-TYPE, not
  40     ;; array type.
  41     (array-type
  42      (values (array-type-specialized-element-type type) nil))
  43     ;; Deal with intersection types (bug #316078)
  44     (intersection-type
  45      (let ((intersection-types (intersection-type-types type))
  46            (element-type *wild-type*)
  47            (element-supertypes nil))
  48        (dolist (intersection-type intersection-types)
  49          (multiple-value-bind (cur-type cur-supertype)
  50              (array-type-upgraded-element-type intersection-type)
  51            ;; According to ANSI, an array may have only one specialized
  52            ;; element type - e.g. '(and (array foo) (array bar))
  53            ;; is not a valid type unless foo and bar upgrade to the
  54            ;; same element type.
  55            (cond
  56              ((eq cur-type *wild-type*)
  57               nil)
  58              ((eq element-type *wild-type*)
  59               (setf element-type cur-type))
  60              ((or (not (csubtypep cur-type element-type))
  61                   (not (csubtypep element-type cur-type)))
  62               ;; At least two different element types where given, the array
  63               ;; is valid iff they represent the same type.
  64               ;;
  65               ;; FIXME: TYPE-INTERSECTION already takes care of disjoint array
  66               ;; types, so I believe this code should be unreachable. Maybe
  67               ;; signal a warning / error instead?
  68               (setf element-type *empty-type*)))
  69            (push (or cur-supertype (type-*-to-t cur-type))
  70                  element-supertypes)))
  71        (values element-type
  72                (when (and (eq *wild-type* element-type) element-supertypes)
  73                  (apply #'type-intersection element-supertypes)))))
  74     (union-type
  75      (let ((union-types (union-type-types type))
  76            (element-type nil)
  77            (element-supertypes nil))
  78        (dolist (union-type union-types)
  79          (multiple-value-bind (cur-type cur-supertype)
  80              (array-type-upgraded-element-type union-type)
  81            (cond
  82              ((eq element-type *wild-type*)
  83               nil)
  84              ((eq element-type nil)
  85               (setf element-type cur-type))
  86              ((or (eq cur-type *wild-type*)
  87                   ;; If each of the two following tests fail, it is not
  88                   ;; possible to determine the element-type of the array
  89                   ;; because more than one kind of element-type was provided
  90                   ;; like in '(or (array foo) (array bar)) although a
  91                   ;; supertype (or foo bar) may be provided as the second
  92                   ;; returned value returned. See also the KLUDGE below.
  93                   (not (csubtypep cur-type element-type))
  94                   (not (csubtypep element-type cur-type)))
  95               (setf element-type *wild-type*)))
  96            (push (or cur-supertype (type-*-to-t cur-type))
  97                  element-supertypes)))
  98        (values element-type
  99                (when (eq *wild-type* element-type)
 100                  (apply #'type-union element-supertypes)))))
 101     (member-type
 102      ;; Convert member-type to an union-type.
 103      (array-type-upgraded-element-type
 104       (apply #'type-union (mapcar #'ctype-of (member-type-members type)))))
 105     (t
 106      ;; KLUDGE: there is no good answer here, but at least
 107      ;; *wild-type* won't cause HAIRY-DATA-VECTOR-{REF,SET} to be
 108      ;; erroneously optimized (see generic/vm-tran.lisp) -- CSR,
 109      ;; 2002-08-21
 110      (values *wild-type* nil))))
 111
 112 (defun array-type-declared-element-type (type)
 113   (if (array-type-p type)
 114       (array-type-element-type type)
 115       *wild-type*))
 116
 117 ;;; The ``new-value'' for array setters must fit in the array, and the
 118 ;;; return type is going to be the same as the new-value for SETF
 119 ;;; functions.
 120 (defun assert-new-value-type (new-value array)
 121   (let ((type (lvar-type array)))
 122     (when (array-type-p type)
 123       (assert-lvar-type
 124        new-value
 125        (array-type-specialized-element-type type)
 126        (lexenv-policy (node-lexenv (lvar-dest new-value))))))
 127   (lvar-type new-value))
 128
 129 ;;; Return true if ARG is NIL, or is a constant-lvar whose
 130 ;;; value is NIL, false otherwise.
 131 (defun unsupplied-or-nil (arg)
 132   (declare (type (or lvar null) arg))
 133   (or (not arg)
 134       (and (constant-lvar-p arg)
 135            (not (lvar-value arg)))))
 136
 137 (defun supplied-and-true (arg)
 138   (and arg
 139        (constant-lvar-p arg)
 140        (lvar-value arg)
 141        t))
 142 \f
 143 ;;;; DERIVE-TYPE optimizers
 144
 145 ;;; Array operations that use a specific number of indices implicitly
 146 ;;; assert that the array is of that rank.
 147 (defun assert-array-rank (array rank)
 148   (assert-lvar-type
 149    array
 150    (specifier-type `(array * ,(make-list rank :initial-element '*)))
 151    (lexenv-policy (node-lexenv (lvar-dest array)))))
 152
 153 (defun derive-aref-type (array)
 154   (multiple-value-bind (uaet other)
 155       (array-type-upgraded-element-type (lvar-type array))
 156     (or other uaet)))
 157
 158 (defoptimizer (array-in-bounds-p derive-type) ((array &rest indices))
 159   (assert-array-rank array (length indices))
 160   *universal-type*)
 161
 162 (deftransform array-in-bounds-p ((array &rest subscripts))
 163   (flet ((give-up ()
 164            (give-up-ir1-transform
 165             "~@<lower array bounds unknown or negative and upper bounds not ~
 166              negative~:@>"))
 167          (bound-known-p (x)
 168            (integerp x))) ; might be NIL or *
 169     (block nil
 170       (let ((dimensions (array-type-dimensions-or-give-up
 171                          (lvar-conservative-type array))))
 172         ;; Might be *. (Note: currently this is never true, because the type
 173         ;; derivation infers the rank from the call to ARRAY-IN-BOUNDS-P, but
 174         ;; let's keep this future proof.)
 175         (when (eq '* dimensions)
 176           (give-up-ir1-transform "array bounds unknown"))
 177         ;; shortcut for zero dimensions
 178         (when (some (lambda (dim)
 179                       (and (bound-known-p dim) (zerop dim)))
 180                     dimensions)
 181           (return nil))
 182         ;; we first collect the subscripts LVARs' bounds and see whether
 183         ;; we can already decide on the result of the optimization without
 184         ;; even taking a look at the dimensions.
 185         (flet ((subscript-bounds (subscript)
 186                  (let* ((type1 (lvar-type subscript))
 187                         (type2 (if (csubtypep type1 (specifier-type 'integer))
 188                                    (weaken-integer-type type1 :range-only t)
 189                                    (give-up)))
 190                         (low (if (integer-type-p type2)
 191                                  (numeric-type-low type2)
 192                                  (give-up)))
 193                         (high (numeric-type-high type2)))
 194                    (cond
 195                      ((and (or (not (bound-known-p low)) (minusp low))
 196                            (or (not (bound-known-p high)) (not (minusp high))))
 197                       ;; can't be sure about the lower bound and the upper bound
 198                       ;; does not give us a definite clue either.
 199                       (give-up))
 200                      ((and (bound-known-p high) (minusp high))
 201                       (return nil))     ; definitely below lower bound (zero).
 202                      (t
 203                       (cons low high))))))
 204           (let* ((subscripts-bounds (mapcar #'subscript-bounds subscripts))
 205                  (subscripts-lower-bound (mapcar #'car subscripts-bounds))
 206                  (subscripts-upper-bound (mapcar #'cdr subscripts-bounds))
 207                  (in-bounds 0))
 208             (mapcar (lambda (low high dim)
 209                       (cond
 210                         ;; first deal with infinite bounds
 211                         ((some (complement #'bound-known-p) (list low high dim))
 212                          (when (and (bound-known-p dim) (bound-known-p low) (<= dim low))
 213                            (return nil)))
 214                         ;; now we know all bounds
 215                         ((>= low dim)
 216                          (return nil))
 217                         ((< high dim)
 218                          (aver (not (minusp low)))
 219                          (incf in-bounds))
 220                         (t
 221                          (give-up))))
 222                     subscripts-lower-bound
 223                     subscripts-upper-bound
 224                     dimensions)
 225             (if (eql in-bounds (length dimensions))
 226                 t
 227                 (give-up))))))))
 228
 229 (defoptimizer (aref derive-type) ((array &rest indices) node)
 230   (assert-array-rank array (length indices))
 231   (derive-aref-type array))
 232
 233 (defoptimizer ((setf aref) derive-type) ((new-value array &rest subscripts))
 234   (assert-array-rank array (length subscripts))
 235   (assert-new-value-type new-value array))
 236
 237 (macrolet ((define (name)
 238              `(defoptimizer (,name derive-type) ((array index))
 239                 (derive-aref-type array))))
 240   (define hairy-data-vector-ref)
 241   (define hairy-data-vector-ref/check-bounds)
 242   (define data-vector-ref))
 243
 244 #!+(or x86 x86-64)
 245 (defoptimizer (data-vector-ref-with-offset derive-type) ((array index offset))
 246   (derive-aref-type array))
 247
 248 (macrolet ((define (name)
 249              `(defoptimizer (,name derive-type) ((array index new-value))
 250                 (assert-new-value-type new-value array))))
 251   (define hairy-data-vector-set)
 252   (define hairy-data-vector-set/check-bounds)
 253   (define data-vector-set))
 254
 255 #!+(or x86 x86-64)
 256 (defoptimizer (data-vector-set-with-offset derive-type) ((array index offset new-value))
 257   (assert-new-value-type new-value array))
 258
 259 ;;; Figure out the type of the data vector if we know the argument
 260 ;;; element type.
 261 (defun derive-%with-array-data/mumble-type (array)
 262   (let ((atype (lvar-type array)))
 263     (when (array-type-p atype)
 264       (specifier-type
 265        `(simple-array ,(type-specifier
 266                         (array-type-specialized-element-type atype))
 267                       (*))))))
 268 (defoptimizer (%with-array-data derive-type) ((array start end))
 269   (derive-%with-array-data/mumble-type array))
 270 (defoptimizer (%with-array-data/fp derive-type) ((array start end))
 271   (derive-%with-array-data/mumble-type array))
 272
 273 (defoptimizer (array-row-major-index derive-type) ((array &rest indices))
 274   (assert-array-rank array (length indices))
 275   *universal-type*)
 276
 277 (defoptimizer (row-major-aref derive-type) ((array index))
 278   (derive-aref-type array))
 279
 280 (defoptimizer (%set-row-major-aref derive-type) ((array index new-value))
 281   (assert-new-value-type new-value array))
 282
 283 (defun derive-make-array-type (dims element-type adjustable
 284                                fill-pointer displaced-to)
 285   (let* ((simple (and (unsupplied-or-nil adjustable)
 286                       (unsupplied-or-nil displaced-to)
 287                       (unsupplied-or-nil fill-pointer)))
 288          (spec
 289            (or `(,(if simple 'simple-array 'array)
 290                  ,(cond ((not element-type) t)
 291                         ((ctype-p element-type)
 292                          (type-specifier element-type))
 293                         ((constant-lvar-p element-type)
 294                          (let ((ctype (careful-specifier-type
 295                                        (lvar-value element-type))))
 296                            (cond
 297                              ((or (null ctype) (contains-unknown-type-p ctype)) '*)
 298                              (t (sb!xc:upgraded-array-element-type
 299                                  (lvar-value element-type))))))
 300                         (t
 301                          '*))
 302                  ,(cond ((constant-lvar-p dims)
 303                          (let* ((val (lvar-value dims))
 304                                 (cdims (if (listp val) val (list val))))
 305                            (if simple
 306                                cdims
 307                                (length cdims))))
 308                         ((csubtypep (lvar-type dims)
 309                                     (specifier-type 'integer))
 310                          '(*))
 311                         (t
 312                          '*)))
 313                'array)))
 314     (if (and (not simple)
 315              (or (supplied-and-true adjustable)
 316                  (supplied-and-true displaced-to)
 317                  (supplied-and-true fill-pointer)))
 318         (careful-specifier-type `(and ,spec (not simple-array)))
 319         (careful-specifier-type spec))))
 320
 321 (defoptimizer (make-array derive-type)
 322     ((dims &key element-type adjustable fill-pointer displaced-to))
 323   (derive-make-array-type dims element-type adjustable
 324                           fill-pointer displaced-to))
 325
 326 (defoptimizer (%make-array derive-type)
 327     ((dims widetag n-bits &key adjustable fill-pointer displaced-to))
 328   (declare (ignore n-bits))
 329   (let ((saetp (and (constant-lvar-p widetag)
 330                     (find (lvar-value widetag)
 331                           sb!vm:*specialized-array-element-type-properties*
 332                           :key #'sb!vm:saetp-typecode))))
 333     (derive-make-array-type dims (if saetp
 334                                      (sb!vm:saetp-ctype saetp)
 335                                      *wild-type*)
 336                             adjustable fill-pointer displaced-to)))
 337
 338 \f
 339 ;;;; constructors
 340
 341 ;;; Convert VECTOR into a MAKE-ARRAY.
 342 (define-source-transform vector (&rest elements)
 343   `(make-array ,(length elements) :initial-contents (list ,@elements)))
 344
 345 ;;; Just convert it into a MAKE-ARRAY.
 346 (deftransform make-string ((length &key
 347                                    (element-type 'character)
 348                                    (initial-element
 349                                     #.*default-init-char-form*)))
 350   `(the simple-string (make-array (the index length)
 351                        :element-type element-type
 352                        ,@(when initial-element
 353                            '(:initial-element initial-element)))))
 354
 355 ;; Traverse the :INTIAL-CONTENTS argument to an array constructor call,
 356 ;; changing the skeleton of the data to be constructed by calls to LIST
 357 ;; and wrapping some declarations around each array cell's constructor.
 358 ;; If a macro is involved, expand it before traversing.
 359 ;; Known bugs:
 360 ;; - Despite the effort to handle multidimensional arrays here,
 361 ;;   an array-header will not be stack-allocated, so the data won't be either.
 362 ;; - inline functions whose behavior is merely to call LIST don't work
 363 ;;   e.g. :INITIAL-CONTENTS (MY-LIST a b) ; where MY-LIST is inline
 364 ;;                                        ; and effectively just (LIST ...)
 365 ;; - in the current implementation it is only with difficulty that
 366 ;;   backquoted vectors could be used as initializers because BACKQ-VECTOR
 367 ;;   is not the analogous function to VECTOR. (New backq macro fixes that.)
 368 (defun rewrite-initial-contents (rank initial-contents env)
 369   (named-let recurse ((rank rank) (data initial-contents))
 370     (declare (index rank))
 371     (if (plusp rank)
 372         (flet ((sequence-constructor-p (form)
 373                  (member (car form) '(list vector sb!impl::backq-list))))
 374           (let (expanded)
 375             (cond ((not (listp data)) data)
 376                   ((sequence-constructor-p data)
 377                    `(list ,@(mapcar (lambda (dim) (recurse (1- rank) dim))
 378                                     (cdr data))))
 379                   ((and (sb!xc:macro-function (car data) env)
 380                         (listp (setq expanded (sb!xc:macroexpand data env)))
 381                         (sequence-constructor-p expanded))
 382                    (recurse rank expanded))
 383                   (t data))))
 384       ;; This is the important bit: once we are past the level of
 385       ;; :INITIAL-CONTENTS that relates to the array structure, reinline LIST
 386       ;; and VECTOR so that nested DX isn't screwed up.
 387         `(locally (declare (inline list vector)) ,data))))
 388
 389 ;;; Prevent open coding DIMENSION and :INITIAL-CONTENTS arguments, so that we
 390 ;;; can pick them apart in the DEFTRANSFORMS, and transform '(3) style
 391 ;;; dimensions to integer args directly.
 392 (define-source-transform make-array (dimensions &rest keyargs &environment env)
 393   (if (or (and (fun-lexically-notinline-p 'list)
 394                (fun-lexically-notinline-p 'vector))
 395           (oddp (length keyargs)))
 396       (values nil t)
 397       (multiple-value-bind (new-dimensions rank)
 398           (flet ((constant-dims (dimensions)
 399                    (let* ((dims (constant-form-value dimensions env))
 400                           (canon (if (listp dims) dims (list dims)))
 401                           (rank (length canon)))
 402                      (values (if (= rank 1)
 403                                  (list 'quote (car canon))
 404                                  (list 'quote canon))
 405                              rank))))
 406             (cond ((sb!xc:constantp dimensions env)
 407                    (constant-dims dimensions))
 408                   ((and (consp dimensions) (eq 'list dimensions))
 409                    (values dimensions (length (cdr dimensions))))
 410                   (t
 411                    (values dimensions nil))))
 412         (let ((initial-contents (getf keyargs :initial-contents)))
 413           (when (and initial-contents rank)
 414             (setf keyargs (copy-list keyargs)
 415                   (getf keyargs :initial-contents)
 416                   (rewrite-initial-contents rank initial-contents env))))
 417         `(locally (declare (notinline list vector))
 418            (make-array ,new-dimensions ,@keyargs)))))
 419
 420 ;;; This baby is a bit of a monster, but it takes care of any MAKE-ARRAY
 421 ;;; call which creates a vector with a known element type -- and tries
 422 ;;; to do a good job with all the different ways it can happen.
 423 (defun transform-make-array-vector (length element-type initial-element
 424                                     initial-contents call)
 425   (aver (or (not element-type) (constant-lvar-p element-type)))
 426   (let* ((c-length (when (constant-lvar-p length)
 427                      (lvar-value length)))
 428          (elt-spec (if element-type
 429                        (lvar-value element-type)
 430                        t))
 431          (elt-ctype (ir1-transform-specifier-type elt-spec))
 432          (saetp (if (unknown-type-p elt-ctype)
 433                     (give-up-ir1-transform "~S is an unknown type: ~S"
 434                                            :element-type elt-spec)
 435                     (find-saetp-by-ctype elt-ctype)))
 436          (default-initial-element (sb!vm:saetp-initial-element-default saetp))
 437          (n-bits (sb!vm:saetp-n-bits saetp))
 438          (typecode (sb!vm:saetp-typecode saetp))
 439          (n-pad-elements (sb!vm:saetp-n-pad-elements saetp))
 440          (n-words-form
 441           (if c-length
 442               (ceiling (* (+ c-length n-pad-elements) n-bits)
 443                        sb!vm:n-word-bits)
 444               (let ((padded-length-form (if (zerop n-pad-elements)
 445                                             'length
 446                                             `(+ length ,n-pad-elements))))
 447                 (cond
 448                   ((= n-bits 0) 0)
 449                   ((>= n-bits sb!vm:n-word-bits)
 450                    `(* ,padded-length-form
 451                        ;; i.e., not RATIO
 452                        ,(the fixnum (/ n-bits sb!vm:n-word-bits))))
 453                   (t
 454                    (let ((n-elements-per-word (/ sb!vm:n-word-bits n-bits)))
 455                      (declare (type index n-elements-per-word)) ; i.e., not RATIO
 456                      `(ceiling (truly-the index ,padded-length-form)
 457                                ,n-elements-per-word)))))))
 458          (result-spec
 459           `(simple-array ,(sb!vm:saetp-specifier saetp) (,(or c-length '*))))
 460          (alloc-form
 461            `(truly-the ,result-spec
 462                        (allocate-vector ,typecode (the index length) ,n-words-form))))
 463     (cond ((and initial-element initial-contents)
 464            (abort-ir1-transform "Both ~S and ~S specified."
 465                                 :initial-contents :initial-element))
 466           ;; :INITIAL-CONTENTS (LIST ...), (VECTOR ...) and `(1 1 ,x) with a
 467           ;; constant LENGTH.
 468           ((and initial-contents c-length
 469                 (lvar-matches initial-contents
 470                               :fun-names '(list vector sb!impl::backq-list)
 471                               :arg-count c-length))
 472            (let ((parameters (eliminate-keyword-args
 473                               call 1 '((:element-type element-type)
 474                                        (:initial-contents initial-contents))))
 475                  (elt-vars (make-gensym-list c-length))
 476                  (lambda-list '(length)))
 477              (splice-fun-args initial-contents :any c-length)
 478              (dolist (p parameters)
 479                (setf lambda-list
 480                      (append lambda-list
 481                              (if (eq p 'initial-contents)
 482                                  elt-vars
 483                                  (list p)))))
 484              `(lambda ,lambda-list
 485                 (declare (type ,elt-spec ,@elt-vars)
 486                          (ignorable ,@lambda-list))
 487                 (truly-the ,result-spec
 488                  (initialize-vector ,alloc-form ,@elt-vars)))))
 489           ;; constant :INITIAL-CONTENTS and LENGTH
 490           ((and initial-contents c-length (constant-lvar-p initial-contents))
 491            (let ((contents (lvar-value initial-contents)))
 492              (unless (= c-length (length contents))
 493                (abort-ir1-transform "~S has ~S elements, vector length is ~S."
 494                                     :initial-contents (length contents) c-length))
 495              (let ((parameters (eliminate-keyword-args
 496                                 call 1 '((:element-type element-type)
 497                                          (:initial-contents initial-contents)))))
 498                `(lambda (length ,@parameters)
 499                   (declare (ignorable ,@parameters))
 500                   (truly-the ,result-spec
 501                    (initialize-vector ,alloc-form
 502                                       ,@(map 'list (lambda (elt)
 503                                                      `(the ,elt-spec ',elt))
 504                                              contents)))))))
 505           ;; any other :INITIAL-CONTENTS
 506           (initial-contents
 507            (let ((parameters (eliminate-keyword-args
 508                               call 1 '((:element-type element-type)
 509                                        (:initial-contents initial-contents)))))
 510              `(lambda (length ,@parameters)
 511                 (declare (ignorable ,@parameters))
 512                 (unless (= length (length initial-contents))
 513                   (error "~S has ~S elements, vector length is ~S."
 514                          :initial-contents (length initial-contents) length))
 515                 (truly-the ,result-spec
 516                            (replace ,alloc-form initial-contents)))))
 517           ;; :INITIAL-ELEMENT, not EQL to the default
 518           ((and initial-element
 519                 (or (not (constant-lvar-p initial-element))
 520                     (not (eql default-initial-element (lvar-value initial-element)))))
 521            (let ((parameters (eliminate-keyword-args
 522                               call 1 '((:element-type element-type)
 523                                        (:initial-element initial-element))))
 524                  (init (if (constant-lvar-p initial-element)
 525                            (list 'quote (lvar-value initial-element))
 526                            'initial-element)))
 527              `(lambda (length ,@parameters)
 528                 (declare (ignorable ,@parameters))
 529                 (truly-the ,result-spec
 530                            (fill ,alloc-form (the ,elt-spec ,init))))))
 531           ;; just :ELEMENT-TYPE, or maybe with :INITIAL-ELEMENT EQL to the
 532           ;; default
 533           (t
 534            #-sb-xc-host
 535            (unless (ctypep default-initial-element elt-ctype)
 536              ;; This situation arises e.g. in (MAKE-ARRAY 4 :ELEMENT-TYPE
 537              ;; '(INTEGER 1 5)) ANSI's definition of MAKE-ARRAY says "If
 538              ;; INITIAL-ELEMENT is not supplied, the consequences of later
 539              ;; reading an uninitialized element of new-array are undefined,"
 540              ;; so this could be legal code as long as the user plans to
 541              ;; write before he reads, and if he doesn't we're free to do
 542              ;; anything we like. But in case the user doesn't know to write
 543              ;; elements before he reads elements (or to read manuals before
 544              ;; he writes code:-), we'll signal a STYLE-WARNING in case he
 545              ;; didn't realize this.
 546              (if initial-element
 547                  (compiler-warn "~S ~S is not a ~S"
 548                                 :initial-element default-initial-element
 549                                 elt-spec)
 550                  (compiler-style-warn "The default initial element ~S is not a ~S."
 551                                       default-initial-element
 552                                       elt-spec)))
 553            (let ((parameters (eliminate-keyword-args
 554                               call 1 '((:element-type element-type)
 555                                        (:initial-element initial-element)))))
 556              `(lambda (length ,@parameters)
 557                 (declare (ignorable ,@parameters))
 558                 ,alloc-form))))))
 559
 560 ;;; IMPORTANT: The order of these three MAKE-ARRAY forms matters: the least
 561 ;;; specific must come first, otherwise suboptimal transforms will result for
 562 ;;; some forms.
 563
 564 (deftransform make-array ((dims &key initial-element element-type
 565                                      adjustable fill-pointer)
 566                           (t &rest *) *
 567                           :node node)
 568   (delay-ir1-transform node :constraint)
 569   (let* ((eltype (cond ((not element-type) t)
 570                        ((not (constant-lvar-p element-type))
 571                         (give-up-ir1-transform
 572                          "ELEMENT-TYPE is not constant."))
 573                        (t
 574                         (lvar-value element-type))))
 575          (eltype-type (ir1-transform-specifier-type eltype))
 576          (saetp (if (unknown-type-p eltype-type)
 577                     (give-up-ir1-transform
 578                      "ELEMENT-TYPE ~s is not a known type"
 579                      eltype-type)
 580                     (find eltype-type
 581                           sb!vm:*specialized-array-element-type-properties*
 582                           :key #'sb!vm:saetp-ctype
 583                           :test #'csubtypep)))
 584          (creation-form `(%make-array
 585                           dims
 586                           ,(if saetp
 587                                (sb!vm:saetp-typecode saetp)
 588                                (give-up-ir1-transform))
 589                           ,(sb!vm:saetp-n-bits saetp)
 590                           ,@(when fill-pointer
 591                               '(:fill-pointer fill-pointer))
 592                           ,@(when adjustable
 593                               '(:adjustable adjustable)))))
 594     (cond ((or (not initial-element)
 595                (and (constant-lvar-p initial-element)
 596                     (eql (lvar-value initial-element)
 597                          (sb!vm:saetp-initial-element-default saetp))))
 598            creation-form)
 599           (t
 600            ;; error checking for target, disabled on the host because
 601            ;; (CTYPE-OF #\Null) is not possible.
 602            #-sb-xc-host
 603            (when (constant-lvar-p initial-element)
 604              (let ((value (lvar-value initial-element)))
 605                (cond
 606                  ((not (ctypep value (sb!vm:saetp-ctype saetp)))
 607                   ;; this case will cause an error at runtime, so we'd
 608                   ;; better WARN about it now.
 609                   (warn 'array-initial-element-mismatch
 610                         :format-control "~@<~S is not a ~S (which is the ~
 611                                          ~S of ~S).~@:>"
 612                         :format-arguments
 613                         (list
 614                          value
 615                          (type-specifier (sb!vm:saetp-ctype saetp))
 616                          'upgraded-array-element-type
 617                          eltype)))
 618                  ((not (ctypep value eltype-type))
 619                   ;; this case will not cause an error at runtime, but
 620                   ;; it's still worth STYLE-WARNing about.
 621                   (compiler-style-warn "~S is not a ~S."
 622                                        value eltype)))))
 623            `(let ((array ,creation-form))
 624               (multiple-value-bind (vector)
 625                   (%data-vector-and-index array 0)
 626                 (fill vector (the ,(sb!vm:saetp-specifier saetp) initial-element)))
 627               array)))))
 628
 629 ;;; The list type restriction does not ensure that the result will be a
 630 ;;; multi-dimensional array. But the lack of adjustable, fill-pointer,
 631 ;;; and displaced-to keywords ensures that it will be simple.
 632 ;;;
 633 ;;; FIXME: should we generalize this transform to non-simple (though
 634 ;;; non-displaced-to) arrays, given that we have %WITH-ARRAY-DATA to
 635 ;;; deal with those? Maybe when the DEFTRANSFORM
 636 ;;; %DATA-VECTOR-AND-INDEX in the VECTOR case problem is solved? --
 637 ;;; CSR, 2002-07-01
 638 (deftransform make-array ((dims &key
 639                                 element-type initial-element initial-contents)
 640                           (list &key
 641                                 (:element-type (constant-arg *))
 642                                 (:initial-element *)
 643                                 (:initial-contents *))
 644                           *
 645                           :node call)
 646   (block make-array
 647     (when (lvar-matches dims :fun-names '(list) :arg-count 1)
 648       (let ((length (car (splice-fun-args dims :any 1))))
 649         (return-from make-array
 650           (transform-make-array-vector length
 651                                        element-type
 652                                        initial-element
 653                                        initial-contents
 654                                        call))))
 655     (unless (constant-lvar-p dims)
 656       (give-up-ir1-transform
 657        "The dimension list is not constant; cannot open code array creation."))
 658     (let ((dims (lvar-value dims))
 659           (element-type-ctype (and (constant-lvar-p element-type)
 660                                    (ir1-transform-specifier-type
 661                                     (lvar-value element-type)))))
 662       (when (contains-unknown-type-p element-type-ctype)
 663         (give-up-ir1-transform))
 664       (unless (every #'integerp dims)
 665         (give-up-ir1-transform
 666          "The dimension list contains something other than an integer: ~S"
 667          dims))
 668       (if (= (length dims) 1)
 669           `(make-array ',(car dims)
 670                        ,@(when element-type
 671                                '(:element-type element-type))
 672                        ,@(when initial-element
 673                                '(:initial-element initial-element))
 674                        ,@(when initial-contents
 675                                '(:initial-contents initial-contents)))
 676           (let* ((total-size (reduce #'* dims))
 677                  (rank (length dims))
 678                  (spec `(simple-array
 679                          ,(cond ((null element-type) t)
 680                                 (element-type-ctype
 681                                  (sb!xc:upgraded-array-element-type
 682                                   (lvar-value element-type)))
 683                                 (t '*))
 684                          ,(make-list rank :initial-element '*))))
 685             `(let ((header (make-array-header sb!vm:simple-array-widetag ,rank))
 686                    (data (make-array ,total-size
 687                                      ,@(when element-type
 688                                              '(:element-type element-type))
 689                                      ,@(when initial-element
 690                                              '(:initial-element initial-element)))))
 691                ,@(when initial-contents
 692                        ;; FIXME: This is could be open coded at least a bit too
 693                        `((sb!impl::fill-data-vector data ',dims initial-contents)))
 694                (setf (%array-fill-pointer header) ,total-size)
 695                (setf (%array-fill-pointer-p header) nil)
 696                (setf (%array-available-elements header) ,total-size)
 697                (setf (%array-data-vector header) data)
 698                (setf (%array-displaced-p header) nil)
 699                (setf (%array-displaced-from header) nil)
 700                ,@(let ((axis -1))
 701                       (mapcar (lambda (dim)
 702                                 `(setf (%array-dimension header ,(incf axis))
 703                                        ,dim))
 704                               dims))
 705                (truly-the ,spec header)))))))
 706
 707 (deftransform make-array ((dims &key element-type initial-element initial-contents)
 708                           (integer &key
 709                                    (:element-type (constant-arg *))
 710                                    (:initial-element *)
 711                                    (:initial-contents *))
 712                           *
 713                           :node call)
 714   (transform-make-array-vector dims
 715                                element-type
 716                                initial-element
 717                                initial-contents
 718                                call))
 719 \f
 720 ;;;; miscellaneous properties of arrays
 721
 722 ;;; Transforms for various array properties. If the property is know
 723 ;;; at compile time because of a type spec, use that constant value.
 724
 725 ;;; Most of this logic may end up belonging in code/late-type.lisp;
 726 ;;; however, here we also need the -OR-GIVE-UP for the transforms, and
 727 ;;; maybe this is just too sloppy for actual type logic.  -- CSR,
 728 ;;; 2004-02-18
 729 (defun array-type-dimensions-or-give-up (type)
 730   (labels ((maybe-array-type-dimensions (type)
 731              (typecase type
 732                (array-type
 733                 (array-type-dimensions type))
 734                (union-type
 735                 (let* ((types (remove nil (mapcar #'maybe-array-type-dimensions
 736                                                   (union-type-types type))))
 737                        (result (car types)))
 738                   (dolist (other (cdr types) result)
 739                     (unless (equal result other)
 740                       (give-up-ir1-transform
 741                        "~@<dimensions of arrays in union type ~S do not match~:@>"
 742                        (type-specifier type))))))
 743                (intersection-type
 744                 (let* ((types (remove nil (mapcar #'maybe-array-type-dimensions
 745                                                   (intersection-type-types type))))
 746                        (result (car types)))
 747                   (dolist (other (cdr types) result)
 748                     (unless (equal result other)
 749                       (abort-ir1-transform
 750                        "~@<dimensions of arrays in intersection type ~S do not match~:@>"
 751                        (type-specifier type)))))))))
 752     (or (maybe-array-type-dimensions type)
 753         (give-up-ir1-transform
 754          "~@<don't know how to extract array dimensions from type ~S~:@>"
 755          (type-specifier type)))))
 756
 757 (defun conservative-array-type-complexp (type)
 758   (typecase type
 759     (array-type (array-type-complexp type))
 760     (union-type
 761      (let ((types (union-type-types type)))
 762        (aver (> (length types) 1))
 763        (let ((result (conservative-array-type-complexp (car types))))
 764          (dolist (type (cdr types) result)
 765            (unless (eq (conservative-array-type-complexp type) result)
 766              (return-from conservative-array-type-complexp :maybe))))))
 767     ;; FIXME: intersection type
 768     (t :maybe)))
 769
 770 ;; Let type derivation handle constant cases. We only do easy strength
 771 ;; reduction.
 772 (deftransform array-rank ((array) (array) * :node node)
 773   (let ((array-type (lvar-type array)))
 774     (cond ((eq t (and (array-type-p array-type)
 775                       (array-type-complexp array-type)))
 776            '(%array-rank array))
 777           (t
 778            (delay-ir1-transform node :constraint)
 779            `(if (array-header-p array)
 780                 (%array-rank array)
 781                 1)))))
 782
 783 (defun derive-array-rank (ctype)
 784   (let ((array (specifier-type 'array)))
 785     (flet ((over (x)
 786              (cond ((not (types-equal-or-intersect x array))
 787                     '()) ; Definitely not an array!
 788                    ((array-type-p x)
 789                     (let ((dims (array-type-dimensions x)))
 790                       (if (eql dims '*)
 791                           '*
 792                           (list (length dims)))))
 793                    (t '*)))
 794            (under (x)
 795              ;; Might as well catch some easy negation cases.
 796              (typecase x
 797                (array-type
 798                 (let ((dims (array-type-dimensions x)))
 799                   (cond ((eql dims '*)
 800                          '*)
 801                         ((every (lambda (dim)
 802                                   (eql dim '*))
 803                                 dims)
 804                          (list (length dims)))
 805                         (t
 806                          '()))))
 807                (t '()))))
 808       (declare (dynamic-extent #'over #'under))
 809       (multiple-value-bind (not-p ranks)
 810           (list-abstract-type-function ctype #'over :under #'under)
 811         (cond ((eql ranks '*)
 812                (aver (not not-p))
 813                nil)
 814               (not-p
 815                (specifier-type `(not (member ,@ranks))))
 816               (t
 817                (specifier-type `(member ,@ranks))))))))
 818
 819 (defoptimizer (array-rank derive-type) ((array))
 820   (derive-array-rank (lvar-type array)))
 821
 822 (defoptimizer (%array-rank derive-type) ((array))
 823   (derive-array-rank (lvar-type array)))
 824
 825 ;;; If we know the dimensions at compile time, just use it. Otherwise,
 826 ;;; if we can tell that the axis is in bounds, convert to
 827 ;;; %ARRAY-DIMENSION (which just indirects the array header) or length
 828 ;;; (if it's simple and a vector).
 829 (deftransform array-dimension ((array axis)
 830                                (array index))
 831   (unless (constant-lvar-p axis)
 832     (give-up-ir1-transform "The axis is not constant."))
 833   ;; Dimensions may change thanks to ADJUST-ARRAY, so we need the
 834   ;; conservative type.
 835   (let ((array-type (lvar-conservative-type array))
 836         (axis (lvar-value axis)))
 837     (let ((dims (array-type-dimensions-or-give-up array-type)))
 838       (unless (listp dims)
 839         (give-up-ir1-transform
 840          "The array dimensions are unknown; must call ARRAY-DIMENSION at runtime."))
 841       (unless (> (length dims) axis)
 842         (abort-ir1-transform "The array has dimensions ~S, ~W is too large."
 843                              dims
 844                              axis))
 845       (let ((dim (nth axis dims)))
 846         (cond ((integerp dim)
 847                dim)
 848               ((= (length dims) 1)
 849                (ecase (conservative-array-type-complexp array-type)
 850                  ((t)
 851                   '(%array-dimension array 0))
 852                  ((nil)
 853                   '(vector-length array))
 854                  ((:maybe)
 855                   `(if (array-header-p array)
 856                        (%array-dimension array axis)
 857                        (vector-length array)))))
 858               (t
 859                '(%array-dimension array axis)))))))
 860
 861 ;;; If the length has been declared and it's simple, just return it.
 862 (deftransform length ((vector)
 863                       ((simple-array * (*))))
 864   (let ((type (lvar-type vector)))
 865     (let ((dims (array-type-dimensions-or-give-up type)))
 866       (unless (and (listp dims) (integerp (car dims)))
 867         (give-up-ir1-transform
 868          "Vector length is unknown, must call LENGTH at runtime."))
 869       (car dims))))
 870
 871 ;;; All vectors can get their length by using VECTOR-LENGTH. If it's
 872 ;;; simple, it will extract the length slot from the vector. It it's
 873 ;;; complex, it will extract the fill pointer slot from the array
 874 ;;; header.
 875 (deftransform length ((vector) (vector))
 876   '(vector-length vector))
 877
 878 ;;; If a simple array with known dimensions, then VECTOR-LENGTH is a
 879 ;;; compile-time constant.
 880 (deftransform vector-length ((vector))
 881   (let ((vtype (lvar-type vector)))
 882     (let ((dim (first (array-type-dimensions-or-give-up vtype))))
 883       (when (eq dim '*)
 884         (give-up-ir1-transform))
 885       (when (conservative-array-type-complexp vtype)
 886         (give-up-ir1-transform))
 887       dim)))
 888
 889 ;;; Again, if we can tell the results from the type, just use it.
 890 ;;; Otherwise, if we know the rank, convert into a computation based
 891 ;;; on array-dimension. We can wrap a TRULY-THE INDEX around the
 892 ;;; multiplications because we know that the total size must be an
 893 ;;; INDEX.
 894 (deftransform array-total-size ((array)
 895                                 (array))
 896   (let ((array-type (lvar-type array)))
 897     (let ((dims (array-type-dimensions-or-give-up array-type)))
 898       (unless (listp dims)
 899         (give-up-ir1-transform "can't tell the rank at compile time"))
 900       (if (member '* dims)
 901           (do ((form 1 `(truly-the index
 902                                    (* (array-dimension array ,i) ,form)))
 903                (i 0 (1+ i)))
 904               ((= i (length dims)) form))
 905           (reduce #'* dims)))))
 906
 907 ;;; Only complex vectors have fill pointers.
 908 (deftransform array-has-fill-pointer-p ((array))
 909   (let ((array-type (lvar-type array)))
 910     (let ((dims (array-type-dimensions-or-give-up array-type)))
 911       (if (and (listp dims) (not (= (length dims) 1)))
 912           nil
 913           (ecase (conservative-array-type-complexp array-type)
 914             ((t)
 915              t)
 916             ((nil)
 917              nil)
 918             ((:maybe)
 919              (give-up-ir1-transform
 920               "The array type is ambiguous; must call ~
 921                ARRAY-HAS-FILL-POINTER-P at runtime.")))))))
 922
 923 ;;; Primitive used to verify indices into arrays. If we can tell at
 924 ;;; compile-time or we are generating unsafe code, don't bother with
 925 ;;; the VOP.
 926 (deftransform %check-bound ((array dimension index) * * :node node)
 927   (cond ((policy node (= insert-array-bounds-checks 0))
 928          'index)
 929         ((not (constant-lvar-p dimension))
 930          (give-up-ir1-transform))
 931         (t
 932          (let ((dim (lvar-value dimension)))
 933            ;; FIXME: Can SPEED > SAFETY weaken this check to INTEGER?
 934            `(the (integer 0 (,dim)) index)))))
 935 \f
 936 ;;;; WITH-ARRAY-DATA
 937
 938 ;;; This checks to see whether the array is simple and the start and
 939 ;;; end are in bounds. If so, it proceeds with those values.
 940 ;;; Otherwise, it calls %WITH-ARRAY-DATA. Note that %WITH-ARRAY-DATA
 941 ;;; may be further optimized.
 942 ;;;
 943 ;;; Given any ARRAY, bind DATA-VAR to the array's data vector and
 944 ;;; START-VAR and END-VAR to the start and end of the designated
 945 ;;; portion of the data vector. SVALUE and EVALUE are any start and
 946 ;;; end specified to the original operation, and are factored into the
 947 ;;; bindings of START-VAR and END-VAR. OFFSET-VAR is the cumulative
 948 ;;; offset of all displacements encountered, and does not include
 949 ;;; SVALUE.
 950 ;;;
 951 ;;; When FORCE-INLINE is set, the underlying %WITH-ARRAY-DATA form is
 952 ;;; forced to be inline, overriding the ordinary judgment of the
 953 ;;; %WITH-ARRAY-DATA DEFTRANSFORMs. Ordinarily the DEFTRANSFORMs are
 954 ;;; fairly picky about their arguments, figuring that if you haven't
 955 ;;; bothered to get all your ducks in a row, you probably don't care
 956 ;;; that much about speed anyway! But in some cases it makes sense to
 957 ;;; do type testing inside %WITH-ARRAY-DATA instead of outside, and
 958 ;;; the DEFTRANSFORM can't tell that that's going on, so it can make
 959 ;;; sense to use FORCE-INLINE option in that case.
 960 (def!macro with-array-data (((data-var array &key offset-var)
 961                              (start-var &optional (svalue 0))
 962                              (end-var &optional (evalue nil))
 963                              &key force-inline check-fill-pointer)
 964                             &body forms
 965                             &environment env)
 966   (once-only ((n-array array)
 967               (n-svalue `(the index ,svalue))
 968               (n-evalue `(the (or index null) ,evalue)))
 969     (let ((check-bounds (policy env (plusp insert-array-bounds-checks))))
 970       `(multiple-value-bind (,data-var
 971                              ,start-var
 972                              ,end-var
 973                              ,@(when offset-var `(,offset-var)))
 974            (if (not (array-header-p ,n-array))
 975                (let ((,n-array ,n-array))
 976                  (declare (type (simple-array * (*)) ,n-array))
 977                  ,(once-only ((n-len (if check-fill-pointer
 978                                          `(length ,n-array)
 979                                          `(array-total-size ,n-array)))
 980                               (n-end `(or ,n-evalue ,n-len)))
 981                              (if check-bounds
 982                                  `(if (<= 0 ,n-svalue ,n-end ,n-len)
 983                                       (values ,n-array ,n-svalue ,n-end 0)
 984                                       ,(if check-fill-pointer
 985                                            `(sequence-bounding-indices-bad-error ,n-array ,n-svalue ,n-evalue)
 986                                            `(array-bounding-indices-bad-error ,n-array ,n-svalue ,n-evalue)))
 987                                  `(values ,n-array ,n-svalue ,n-end 0))))
 988                ,(if force-inline
 989                     `(%with-array-data-macro ,n-array ,n-svalue ,n-evalue
 990                                              :check-bounds ,check-bounds
 991                                              :check-fill-pointer ,check-fill-pointer)
 992                     (if check-fill-pointer
 993                         `(%with-array-data/fp ,n-array ,n-svalue ,n-evalue)
 994                         `(%with-array-data ,n-array ,n-svalue ,n-evalue))))
 995          ,@forms))))
 996
 997 ;;; This is the fundamental definition of %WITH-ARRAY-DATA, for use in
 998 ;;; DEFTRANSFORMs and DEFUNs.
 999 (def!macro %with-array-data-macro (array
1000                                    start
1001                                    end
1002                                    &key
1003                                    (element-type '*)
1004                                    check-bounds
1005                                    check-fill-pointer)
1006   (with-unique-names (size defaulted-end data cumulative-offset)
1007     `(let* ((,size ,(if check-fill-pointer
1008                         `(length ,array)
1009                         `(array-total-size ,array)))
1010             (,defaulted-end (or ,end ,size)))
1011        ,@(when check-bounds
1012                `((unless (<= ,start ,defaulted-end ,size)
1013                    ,(if check-fill-pointer
1014                         `(sequence-bounding-indices-bad-error ,array ,start ,end)
1015                         `(array-bounding-indices-bad-error ,array ,start ,end)))))
1016        (do ((,data ,array (%array-data-vector ,data))
1017             (,cumulative-offset 0
1018                                 (+ ,cumulative-offset
1019                                    (%array-displacement ,data))))
1020            ((not (array-header-p ,data))
1021             (values (the (simple-array ,element-type 1) ,data)
1022                     (the index (+ ,cumulative-offset ,start))
1023                     (the index (+ ,cumulative-offset ,defaulted-end))
1024                     (the index ,cumulative-offset)))
1025          (declare (type index ,cumulative-offset))))))
1026
1027 (defun transform-%with-array-data/muble (array node check-fill-pointer)
1028   (let ((element-type (upgraded-element-type-specifier-or-give-up array))
1029         (type (lvar-type array))
1030         (check-bounds (policy node (plusp insert-array-bounds-checks))))
1031     (if (and (array-type-p type)
1032              (not (array-type-complexp type))
1033              (listp (array-type-dimensions type))
1034              (not (null (cdr (array-type-dimensions type)))))
1035         ;; If it's a simple multidimensional array, then just return
1036         ;; its data vector directly rather than going through
1037         ;; %WITH-ARRAY-DATA-MACRO. SBCL doesn't generally generate
1038         ;; code that would use this currently, but we have encouraged
1039         ;; users to use WITH-ARRAY-DATA and we may use it ourselves at
1040         ;; some point in the future for optimized libraries or
1041         ;; similar.
1042         (if check-bounds
1043             `(let* ((data (truly-the (simple-array ,element-type (*))
1044                                      (%array-data-vector array)))
1045                     (len (length data))
1046                     (real-end (or end len)))
1047                (unless (<= 0 start data-end lend)
1048                  (sequence-bounding-indices-bad-error array start end))
1049                (values data 0 real-end 0))
1050             `(let ((data (truly-the (simple-array ,element-type (*))
1051                                     (%array-data-vector array))))
1052                (values data 0 (or end (length data)) 0)))
1053         `(%with-array-data-macro array start end
1054                                  :check-fill-pointer ,check-fill-pointer
1055                                  :check-bounds ,check-bounds
1056                                  :element-type ,element-type))))
1057
1058 ;; It might very well be reasonable to allow general ARRAY here, I
1059 ;; just haven't tried to understand the performance issues involved.
1060 ;; -- WHN, and also CSR 2002-05-26
1061 (deftransform %with-array-data ((array start end)
1062                                 ((or vector simple-array) index (or index null) t)
1063                                 *
1064                                 :node node
1065                                 :policy (> speed space))
1066   "inline non-SIMPLE-vector-handling logic"
1067   (transform-%with-array-data/muble array node nil))
1068 (deftransform %with-array-data/fp ((array start end)
1069                                 ((or vector simple-array) index (or index null) t)
1070                                 *
1071                                 :node node
1072                                 :policy (> speed space))
1073   "inline non-SIMPLE-vector-handling logic"
1074   (transform-%with-array-data/muble array node t))
1075 \f
1076 ;;;; array accessors
1077
1078 ;;; We convert all typed array accessors into AREF and (SETF AREF) with type
1079 ;;; assertions on the array.
1080 (macrolet ((define-bit-frob (reffer simplep)
1081              `(progn
1082                 (define-source-transform ,reffer (a &rest i)
1083                   `(aref (the (,',(if simplep 'simple-array 'array)
1084                                   bit
1085                                   ,(mapcar (constantly '*) i))
1086                            ,a) ,@i))
1087                 (define-source-transform (setf ,reffer) (value a &rest i)
1088                   `(setf (aref (the (,',(if simplep 'simple-array 'array)
1089                                      bit
1090                                      ,(mapcar (constantly '*) i))
1091                                     ,a) ,@i)
1092                          ,value)))))
1093   (define-bit-frob sbit t)
1094   (define-bit-frob bit nil))
1095
1096 (macrolet ((define-frob (reffer setter type)
1097              `(progn
1098                 (define-source-transform ,reffer (a i)
1099                   `(aref (the ,',type ,a) ,i))
1100                 (define-source-transform ,setter (a i v)
1101                   `(setf (aref (the ,',type ,a) ,i) ,v)))))
1102   (define-frob schar %scharset simple-string)
1103   (define-frob char %charset string))
1104
1105 ;;; We transform SVREF and %SVSET directly into DATA-VECTOR-REF/SET: this is
1106 ;;; around 100 times faster than going through the general-purpose AREF
1107 ;;; transform which ends up doing a lot of work -- and introducing many
1108 ;;; intermediate lambdas, each meaning a new trip through the compiler -- to
1109 ;;; get the same result.
1110 ;;;
1111 ;;; FIXME: [S]CHAR, and [S]BIT above would almost certainly benefit from a similar
1112 ;;; treatment.
1113 (define-source-transform svref (vector index)
1114   (let ((elt-type (or (when (symbolp vector)
1115                         (let ((var (lexenv-find vector vars)))
1116                           (when (lambda-var-p var)
1117                             (type-specifier
1118                              (array-type-declared-element-type (lambda-var-type var))))))
1119                       t)))
1120     (with-unique-names (n-vector)
1121       `(let ((,n-vector ,vector))
1122          (the ,elt-type (data-vector-ref
1123                          (the simple-vector ,n-vector)
1124                          (%check-bound ,n-vector (length ,n-vector) ,index)))))))
1125
1126 (define-source-transform %svset (vector index value)
1127   (let ((elt-type (or (when (symbolp vector)
1128                         (let ((var (lexenv-find vector vars)))
1129                           (when (lambda-var-p var)
1130                             (type-specifier
1131                              (array-type-declared-element-type (lambda-var-type var))))))
1132                       t)))
1133     (with-unique-names (n-vector)
1134       `(let ((,n-vector ,vector))
1135          (truly-the ,elt-type (data-vector-set
1136                                (the simple-vector ,n-vector)
1137                                (%check-bound ,n-vector (length ,n-vector) ,index)
1138                                (the ,elt-type ,value)))))))
1139
1140 (macrolet (;; This is a handy macro for computing the row-major index
1141            ;; given a set of indices. We wrap each index with a call
1142            ;; to %CHECK-BOUND to ensure that everything works out
1143            ;; correctly. We can wrap all the interior arithmetic with
1144            ;; TRULY-THE INDEX because we know the resultant
1145            ;; row-major index must be an index.
1146            (with-row-major-index ((array indices index &optional new-value)
1147                                   &rest body)
1148              `(let (n-indices dims)
1149                 (dotimes (i (length ,indices))
1150                   (push (make-symbol (format nil "INDEX-~D" i)) n-indices)
1151                   (push (make-symbol (format nil "DIM-~D" i)) dims))
1152                 (setf n-indices (nreverse n-indices))
1153                 (setf dims (nreverse dims))
1154                 `(lambda (,@',(when new-value (list new-value))
1155                           ,',array ,@n-indices)
1156                    (declare (ignorable ,',array))
1157                    (let* (,@(let ((,index -1))
1158                               (mapcar (lambda (name)
1159                                         `(,name (array-dimension
1160                                                  ,',array
1161                                                  ,(incf ,index))))
1162                                       dims))
1163                             (,',index
1164                              ,(if (null dims)
1165                                   0
1166                                 (do* ((dims dims (cdr dims))
1167                                       (indices n-indices (cdr indices))
1168                                       (last-dim nil (car dims))
1169                                       (form `(%check-bound ,',array
1170                                                            ,(car dims)
1171                                                            ,(car indices))
1172                                             `(truly-the
1173                                               index
1174                                               (+ (truly-the index
1175                                                             (* ,form
1176                                                                ,last-dim))
1177                                                  (%check-bound
1178                                                   ,',array
1179                                                   ,(car dims)
1180                                                   ,(car indices))))))
1181                                     ((null (cdr dims)) form)))))
1182                      ,',@body)))))
1183
1184   ;; Just return the index after computing it.
1185   (deftransform array-row-major-index ((array &rest indices))
1186     (with-row-major-index (array indices index)
1187       index))
1188
1189   ;; Convert AREF and (SETF AREF) into a HAIRY-DATA-VECTOR-REF (or
1190   ;; HAIRY-DATA-VECTOR-SET) with the set of indices replaced with the an
1191   ;; expression for the row major index.
1192   (deftransform aref ((array &rest indices))
1193     (with-row-major-index (array indices index)
1194       (hairy-data-vector-ref array index)))
1195
1196   (deftransform (setf aref) ((new-value array &rest subscripts))
1197     (with-row-major-index (array subscripts index new-value)
1198                           (hairy-data-vector-set array index new-value))))
1199
1200 ;; For AREF of vectors we do the bounds checking in the callee. This
1201 ;; lets us do a significantly more efficient check for simple-arrays
1202 ;; without bloating the code. If we already know the type of the array
1203 ;; with sufficient precision, skip directly to DATA-VECTOR-REF.
1204 (deftransform aref ((array index) (t t) * :node node)
1205   (let* ((type (lvar-type array))
1206          (element-ctype (array-type-upgraded-element-type type)))
1207     (cond
1208       ((eql element-ctype *empty-type*)
1209        `(data-nil-vector-ref array index))
1210       ((and (array-type-p type)
1211             (null (array-type-complexp type))
1212             (not (eql element-ctype *wild-type*))
1213             (eql (length (array-type-dimensions type)) 1))
1214        (let* ((declared-element-ctype (array-type-declared-element-type type))
1215               (bare-form
1216                 `(data-vector-ref array
1217                                   (%check-bound array (array-dimension array 0) index))))
1218          (if (type= declared-element-ctype element-ctype)
1219              bare-form
1220              `(the ,(type-specifier declared-element-ctype) ,bare-form))))
1221       ((policy node (zerop insert-array-bounds-checks))
1222        `(hairy-data-vector-ref array index))
1223       (t `(hairy-data-vector-ref/check-bounds array index)))))
1224
1225 (deftransform (setf aref) ((new-value array index) (t t t) * :node node)
1226   (if (policy node (zerop insert-array-bounds-checks))
1227       `(hairy-data-vector-set array index new-value)
1228       `(hairy-data-vector-set/check-bounds array index new-value)))
1229
1230 ;;; But if we find out later that there's some useful type information
1231 ;;; available, switch back to the normal one to give other transforms
1232 ;;; a stab at it.
1233 (macrolet ((define (name transform-to extra extra-type)
1234              (declare (ignore extra-type))
1235              `(deftransform ,name ((array index ,@extra))
1236                 (let* ((type (lvar-type array))
1237                        (element-type (array-type-upgraded-element-type type))
1238                        (declared-type (type-specifier
1239                                        (array-type-declared-element-type type))))
1240                   ;; If an element type has been declared, we want to
1241                   ;; use that information it for type checking (even
1242                   ;; if the access can't be optimized due to the array
1243                   ;; not being simple).
1244                   (when (and (eql element-type *wild-type*)
1245                              ;; This type logic corresponds to the special
1246                              ;; case for strings in HAIRY-DATA-VECTOR-REF
1247                              ;; (generic/vm-tran.lisp)
1248                              (not (csubtypep type (specifier-type 'simple-string))))
1249                     (when (or (not (array-type-p type))
1250                               ;; If it's a simple array, we might be able
1251                               ;; to inline the access completely.
1252                               (not (null (array-type-complexp type))))
1253                       (give-up-ir1-transform
1254                        "Upgraded element type of array is not known at compile time.")))
1255                   ,(if extra
1256                        ``(truly-the ,declared-type
1257                                     (,',transform-to array
1258                                                      (%check-bound array
1259                                                                    (array-dimension array 0)
1260                                                                    index)
1261                                                      (the ,declared-type ,@',extra)))
1262                        ``(the ,declared-type
1263                            (,',transform-to array
1264                                             (%check-bound array
1265                                                           (array-dimension array 0)
1266                                                           index))))))))
1267   (define hairy-data-vector-ref/check-bounds
1268       hairy-data-vector-ref nil nil)
1269   (define hairy-data-vector-set/check-bounds
1270       hairy-data-vector-set (new-value) (*)))
1271
1272 ;;; Just convert into a HAIRY-DATA-VECTOR-REF (or
1273 ;;; HAIRY-DATA-VECTOR-SET) after checking that the index is inside the
1274 ;;; array total size.
1275 (deftransform row-major-aref ((array index))
1276   `(hairy-data-vector-ref array
1277                           (%check-bound array (array-total-size array) index)))
1278 (deftransform %set-row-major-aref ((array index new-value))
1279   `(hairy-data-vector-set array
1280                           (%check-bound array (array-total-size array) index)
1281                           new-value))
1282 \f
1283 ;;;; bit-vector array operation canonicalization
1284 ;;;;
1285 ;;;; We convert all bit-vector operations to have the result array
1286 ;;;; specified. This allows any result allocation to be open-coded,
1287 ;;;; and eliminates the need for any VM-dependent transforms to handle
1288 ;;;; these cases.
1289
1290 (macrolet ((def (fun)
1291              `(progn
1292                (deftransform ,fun ((bit-array-1 bit-array-2
1293                                                 &optional result-bit-array)
1294                                    (bit-vector bit-vector &optional null) *
1295                                    :policy (>= speed space))
1296                  `(,',fun bit-array-1 bit-array-2
1297                    (make-array (array-dimension bit-array-1 0) :element-type 'bit)))
1298                ;; If result is T, make it the first arg.
1299                (deftransform ,fun ((bit-array-1 bit-array-2 result-bit-array)
1300                                    (bit-vector bit-vector (eql t)) *)
1301                  `(,',fun bit-array-1 bit-array-2 bit-array-1)))))
1302   (def bit-and)
1303   (def bit-ior)
1304   (def bit-xor)
1305   (def bit-eqv)
1306   (def bit-nand)
1307   (def bit-nor)
1308   (def bit-andc1)
1309   (def bit-andc2)
1310   (def bit-orc1)
1311   (def bit-orc2))
1312
1313 ;;; Similar for BIT-NOT, but there is only one arg...
1314 (deftransform bit-not ((bit-array-1 &optional result-bit-array)
1315                        (bit-vector &optional null) *
1316                        :policy (>= speed space))
1317   '(bit-not bit-array-1
1318             (make-array (array-dimension bit-array-1 0) :element-type 'bit)))
1319 (deftransform bit-not ((bit-array-1 result-bit-array)
1320                        (bit-vector (eql t)))
1321   '(bit-not bit-array-1 bit-array-1))
1322 \f
1323 ;;; Pick off some constant cases.
1324 (defoptimizer (array-header-p derive-type) ((array))
1325   (let ((type (lvar-type array)))
1326     (cond ((not (array-type-p type))
1327            ;; FIXME: use analogue of ARRAY-TYPE-DIMENSIONS-OR-GIVE-UP
1328            nil)
1329           (t
1330            (let ((dims (array-type-dimensions type)))
1331              (cond ((csubtypep type (specifier-type '(simple-array * (*))))
1332                     ;; no array header
1333                     (specifier-type 'null))
1334                    ((and (listp dims) (/= (length dims) 1))
1335                     ;; multi-dimensional array, will have a header
1336                     (specifier-type '(eql t)))
1337                    ((eql (array-type-complexp type) t)
1338                     (specifier-type '(eql t)))
1339                    (t
1340                     nil)))))))