src/compiler/aliencomp.lisp

   1 ;;;; transforms and other stuff used to compile ALIEN operations
   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 ;;;; DEFKNOWNs
  15
  16 (defknown %sap-alien (system-area-pointer alien-type) alien-value
  17   (flushable movable))
  18 (defknown alien-sap (alien-value) system-area-pointer
  19   (flushable movable))
  20
  21 (defknown slot (alien-value symbol) t
  22   (flushable recursive))
  23 (defknown %set-slot (alien-value symbol t) t
  24   (recursive))
  25 (defknown %slot-addr (alien-value symbol) (alien (* t))
  26   (flushable movable recursive))
  27
  28 (defknown deref (alien-value &rest index) t
  29   (flushable))
  30 (defknown %set-deref (alien-value t &rest index) t
  31   ())
  32 (defknown %deref-addr (alien-value &rest index) (alien (* t))
  33   (flushable movable))
  34
  35 (defknown %heap-alien (heap-alien-info) t
  36   (flushable))
  37 (defknown %set-heap-alien (heap-alien-info t) t
  38   ())
  39 (defknown %heap-alien-addr (heap-alien-info) (alien (* t))
  40   (flushable movable))
  41
  42 (defknown make-local-alien (local-alien-info) t
  43   ())
  44 (defknown note-local-alien-type (local-alien-info t) null
  45   ())
  46 (defknown local-alien (local-alien-info t) t
  47   (flushable))
  48 (defknown %local-alien-forced-to-memory-p (local-alien-info) (member t nil)
  49   (movable))
  50 (defknown %set-local-alien (local-alien-info t t) t
  51   ())
  52 (defknown %local-alien-addr (local-alien-info t) (alien (* t))
  53   (flushable movable))
  54 (defknown dispose-local-alien (local-alien-info t) t
  55   ())
  56
  57 (defknown %cast (alien-value alien-type) alien
  58   (flushable movable))
  59
  60 (defknown naturalize (t alien-type) alien
  61   (flushable movable))
  62 (defknown deport (alien alien-type) t
  63   (flushable movable))
  64 (defknown extract-alien-value (system-area-pointer unsigned-byte alien-type) t
  65   (flushable))
  66 (defknown deposit-alien-value (system-area-pointer unsigned-byte alien-type t) t
  67   ())
  68
  69 (defknown alien-funcall (alien-value &rest *) *
  70   (any recursive))
  71 \f
  72 ;;;; cosmetic transforms
  73
  74 (deftransform slot ((object slot)
  75                     ((alien (* t)) symbol))
  76   '(slot (deref object) slot))
  77
  78 (deftransform %set-slot ((object slot value)
  79                          ((alien (* t)) symbol t))
  80   '(%set-slot (deref object) slot value))
  81
  82 (deftransform %slot-addr ((object slot)
  83                           ((alien (* t)) symbol))
  84   '(%slot-addr (deref object) slot))
  85 \f
  86 ;;;; SLOT support
  87
  88 (defun find-slot-offset-and-type (alien slot)
  89   (unless (constant-lvar-p slot)
  90     (give-up-ir1-transform
  91      "The slot is not constant, so access cannot be open coded."))
  92   (let ((type (lvar-type alien)))
  93     (unless (alien-type-type-p type)
  94       (give-up-ir1-transform))
  95     (let ((alien-type (alien-type-type-alien-type type)))
  96       (unless (alien-record-type-p alien-type)
  97         (give-up-ir1-transform))
  98       (let* ((slot-name (lvar-value slot))
  99              (field (find slot-name (alien-record-type-fields alien-type)
 100                           :key #'alien-record-field-name)))
 101         (unless field
 102           (abort-ir1-transform "~S doesn't have a slot named ~S"
 103                                alien
 104                                slot-name))
 105         (values (alien-record-field-offset field)
 106                 (alien-record-field-type field))))))
 107
 108 #+nil ;; Shouldn't be necessary.
 109 (defoptimizer (slot derive-type) ((alien slot))
 110   (block nil
 111     (catch 'give-up-ir1-transform
 112       (multiple-value-bind (slot-offset slot-type)
 113           (find-slot-offset-and-type alien slot)
 114         (declare (ignore slot-offset))
 115         (return (make-alien-type-type slot-type))))
 116     *wild-type*))
 117
 118 (deftransform slot ((alien slot) * * :important t)
 119   (multiple-value-bind (slot-offset slot-type)
 120       (find-slot-offset-and-type alien slot)
 121     `(extract-alien-value (alien-sap alien)
 122                           ,slot-offset
 123                           ',slot-type)))
 124
 125 #+nil ;; ### But what about coercions?
 126 (defoptimizer (%set-slot derive-type) ((alien slot value))
 127   (block nil
 128     (catch 'give-up-ir1-transform
 129       (multiple-value-bind (slot-offset slot-type)
 130           (find-slot-offset-and-type alien slot)
 131         (declare (ignore slot-offset))
 132         (let ((type (make-alien-type-type slot-type)))
 133           (assert-lvar-type value type)
 134           (return type))))
 135     *wild-type*))
 136
 137 (deftransform %set-slot ((alien slot value) * * :important t)
 138   (multiple-value-bind (slot-offset slot-type)
 139       (find-slot-offset-and-type alien slot)
 140     `(deposit-alien-value (alien-sap alien)
 141                           ,slot-offset
 142                           ',slot-type
 143                           value)))
 144
 145 (defoptimizer (%slot-addr derive-type) ((alien slot))
 146   (block nil
 147     (catch 'give-up-ir1-transform
 148       (multiple-value-bind (slot-offset slot-type)
 149           (find-slot-offset-and-type alien slot)
 150         (declare (ignore slot-offset))
 151         (return (make-alien-type-type
 152                  (make-alien-pointer-type :to slot-type)))))
 153     *wild-type*))
 154
 155 (deftransform %slot-addr ((alien slot) * * :important t)
 156   (multiple-value-bind (slot-offset slot-type)
 157       (find-slot-offset-and-type alien slot)
 158     (/noshow "in DEFTRANSFORM %SLOT-ADDR, creating %SAP-ALIEN")
 159     `(%sap-alien (sap+ (alien-sap alien) (/ ,slot-offset sb!vm:n-byte-bits))
 160                  ',(make-alien-pointer-type :to slot-type))))
 161 \f
 162 ;;;; DEREF support
 163
 164 (defun find-deref-alien-type (alien)
 165   (let ((alien-type (lvar-type alien)))
 166     (unless (alien-type-type-p alien-type)
 167       (give-up-ir1-transform))
 168     (let ((alien-type (alien-type-type-alien-type alien-type)))
 169       (if (alien-type-p alien-type)
 170           alien-type
 171           (give-up-ir1-transform)))))
 172
 173 (defun find-deref-element-type (alien)
 174   (let ((alien-type (find-deref-alien-type alien)))
 175     (typecase alien-type
 176       (alien-pointer-type
 177        (alien-pointer-type-to alien-type))
 178       (alien-array-type
 179        (alien-array-type-element-type alien-type))
 180       (t
 181        (give-up-ir1-transform)))))
 182
 183 (defun compute-deref-guts (alien indices)
 184   (let ((alien-type (find-deref-alien-type alien)))
 185     (typecase alien-type
 186       (alien-pointer-type
 187        (when (cdr indices)
 188          (abort-ir1-transform "too many indices for pointer deref: ~W"
 189                               (length indices)))
 190        (let ((element-type (alien-pointer-type-to alien-type)))
 191          (if indices
 192              (let ((bits (alien-type-bits element-type))
 193                    (alignment (alien-type-alignment element-type)))
 194                (unless bits
 195                  (abort-ir1-transform "unknown element size"))
 196                (unless alignment
 197                  (abort-ir1-transform "unknown element alignment"))
 198                (values '(offset)
 199                        `(* offset
 200                            ,(align-offset bits alignment))
 201                        element-type))
 202              (values nil 0 element-type))))
 203       (alien-array-type
 204        (let* ((element-type (alien-array-type-element-type alien-type))
 205               (bits (alien-type-bits element-type))
 206               (alignment (alien-type-alignment element-type))
 207               (dims (alien-array-type-dimensions alien-type)))
 208          (unless (= (length indices) (length dims))
 209            (give-up-ir1-transform "incorrect number of indices"))
 210          (unless bits
 211            (give-up-ir1-transform "Element size is unknown."))
 212          (unless alignment
 213            (give-up-ir1-transform "Element alignment is unknown."))
 214          (if (null dims)
 215              (values nil 0 element-type)
 216              (let* ((arg (gensym))
 217                     (args (list arg))
 218                     (offsetexpr arg))
 219                (dolist (dim (cdr dims))
 220                  (let ((arg (gensym)))
 221                    (push arg args)
 222                    (setf offsetexpr `(+ (* ,offsetexpr ,dim) ,arg))))
 223                (values (reverse args)
 224                        `(* ,offsetexpr
 225                            ,(align-offset bits alignment))
 226                        element-type)))))
 227       (t
 228        (abort-ir1-transform "~S not either a pointer or array type."
 229                             alien-type)))))
 230
 231 #+nil ;; Shouldn't be necessary.
 232 (defoptimizer (deref derive-type) ((alien &rest noise))
 233   (declare (ignore noise))
 234   (block nil
 235     (catch 'give-up-ir1-transform
 236       (return (make-alien-type-type (find-deref-element-type alien))))
 237     *wild-type*))
 238
 239 (deftransform deref ((alien &rest indices) * * :important t)
 240   (multiple-value-bind (indices-args offset-expr element-type)
 241       (compute-deref-guts alien indices)
 242     `(lambda (alien ,@indices-args)
 243        (extract-alien-value (alien-sap alien)
 244                             ,offset-expr
 245                             ',element-type))))
 246
 247 #+nil ;; ### Again, the value might be coerced.
 248 (defoptimizer (%set-deref derive-type) ((alien value &rest noise))
 249   (declare (ignore noise))
 250   (block nil
 251     (catch 'give-up-ir1-transform
 252       (let ((type (make-alien-type-type
 253                    (make-alien-pointer-type
 254                     :to (find-deref-element-type alien)))))
 255         (assert-lvar-type value type)
 256         (return type)))
 257     *wild-type*))
 258
 259 (deftransform %set-deref ((alien value &rest indices) * * :important t)
 260   (multiple-value-bind (indices-args offset-expr element-type)
 261       (compute-deref-guts alien indices)
 262     `(lambda (alien value ,@indices-args)
 263        (deposit-alien-value (alien-sap alien)
 264                             ,offset-expr
 265                             ',element-type
 266                             value))))
 267
 268 (defoptimizer (%deref-addr derive-type) ((alien &rest noise))
 269   (declare (ignore noise))
 270   (block nil
 271     (catch 'give-up-ir1-transform
 272       (return (make-alien-type-type
 273                (make-alien-pointer-type
 274                 :to (find-deref-element-type alien)))))
 275     *wild-type*))
 276
 277 (deftransform %deref-addr ((alien &rest indices) * * :important t)
 278   (multiple-value-bind (indices-args offset-expr element-type)
 279       (compute-deref-guts alien indices)
 280     (/noshow "in DEFTRANSFORM %DEREF-ADDR, creating (LAMBDA .. %SAP-ALIEN)")
 281     `(lambda (alien ,@indices-args)
 282        (%sap-alien (sap+ (alien-sap alien) (/ ,offset-expr sb!vm:n-byte-bits))
 283                    ',(make-alien-pointer-type :to element-type)))))
 284 \f
 285 ;;;; support for aliens on the heap
 286
 287 (defun heap-alien-sap-and-type (info)
 288   (unless (constant-lvar-p info)
 289     (give-up-ir1-transform "info not constant; can't open code"))
 290   (let ((info (lvar-value info)))
 291     (values (heap-alien-info-sap-form info)
 292             (heap-alien-info-type info))))
 293
 294 #+nil ; shouldn't be necessary
 295 (defoptimizer (%heap-alien derive-type) ((info))
 296   (block nil
 297     (catch 'give-up
 298       (multiple-value-bind (sap type) (heap-alien-sap-and-type info)
 299         (declare (ignore sap))
 300         (return (make-alien-type-type type))))
 301     *wild-type*))
 302
 303 (deftransform %heap-alien ((info) * * :important t)
 304   (multiple-value-bind (sap type) (heap-alien-sap-and-type info)
 305     `(extract-alien-value ,sap 0 ',type)))
 306
 307 #+nil ;; ### Again, deposit value might change the type.
 308 (defoptimizer (%set-heap-alien derive-type) ((info value))
 309   (block nil
 310     (catch 'give-up-ir1-transform
 311       (multiple-value-bind (sap type) (heap-alien-sap-and-type info)
 312         (declare (ignore sap))
 313         (let ((type (make-alien-type-type type)))
 314           (assert-lvar-type value type)
 315           (return type))))
 316     *wild-type*))
 317
 318 (deftransform %set-heap-alien ((info value) (heap-alien-info *) * :important t)
 319   (multiple-value-bind (sap type) (heap-alien-sap-and-type info)
 320     `(deposit-alien-value ,sap 0 ',type value)))
 321
 322 (defoptimizer (%heap-alien-addr derive-type) ((info))
 323   (block nil
 324     (catch 'give-up-ir1-transform
 325       (multiple-value-bind (sap type) (heap-alien-sap-and-type info)
 326         (declare (ignore sap))
 327         (return (make-alien-type-type (make-alien-pointer-type :to type)))))
 328     *wild-type*))
 329
 330 (deftransform %heap-alien-addr ((info) * * :important t)
 331   (multiple-value-bind (sap type) (heap-alien-sap-and-type info)
 332     (/noshow "in DEFTRANSFORM %HEAP-ALIEN-ADDR, creating %SAP-ALIEN")
 333     `(%sap-alien ,sap ',type)))
 334 \f
 335 ;;;; support for local (stack or register) aliens
 336
 337 (deftransform make-local-alien ((info) * * :important t)
 338   (unless (constant-lvar-p info)
 339     (abort-ir1-transform "Local alien info isn't constant?"))
 340   (let* ((info (lvar-value info))
 341          (alien-type (local-alien-info-type info))
 342          (bits (alien-type-bits alien-type)))
 343     (unless bits
 344       (abort-ir1-transform "unknown size: ~S" (unparse-alien-type alien-type)))
 345     (/noshow "in DEFTRANSFORM MAKE-LOCAL-ALIEN" info)
 346     (/noshow (local-alien-info-force-to-memory-p info))
 347     (/noshow alien-type (unparse-alien-type alien-type) (alien-type-bits alien-type))
 348     (if (local-alien-info-force-to-memory-p info)
 349       #!+x86 `(truly-the system-area-pointer
 350                          (%primitive alloc-alien-stack-space
 351                                      ,(ceiling (alien-type-bits alien-type)
 352                                                sb!vm:n-byte-bits)))
 353       #!-x86 `(truly-the system-area-pointer
 354                          (%primitive alloc-number-stack-space
 355                                      ,(ceiling (alien-type-bits alien-type)
 356                                                sb!vm:n-byte-bits)))
 357       (let* ((alien-rep-type-spec (compute-alien-rep-type alien-type))
 358              (alien-rep-type (specifier-type alien-rep-type-spec)))
 359         (cond ((csubtypep (specifier-type 'system-area-pointer)
 360                           alien-rep-type)
 361                '(int-sap 0))
 362               ((ctypep 0 alien-rep-type) 0)
 363               ((ctypep 0.0f0 alien-rep-type) 0.0f0)
 364               ((ctypep 0.0d0 alien-rep-type) 0.0d0)
 365               (t
 366                (compiler-error
 367                 "Aliens of type ~S cannot be represented immediately."
 368                 (unparse-alien-type alien-type))))))))
 369
 370 (deftransform note-local-alien-type ((info var) * * :important t)
 371   ;; FIXME: This test and error occur about a zillion times. They
 372   ;; could be factored into a function.
 373   (unless (constant-lvar-p info)
 374     (abort-ir1-transform "Local alien info isn't constant?"))
 375   (let ((info (lvar-value info)))
 376     (/noshow "in DEFTRANSFORM NOTE-LOCAL-ALIEN-TYPE" info)
 377     (/noshow (local-alien-info-force-to-memory-p info))
 378     (unless (local-alien-info-force-to-memory-p info)
 379       (let ((var-node (lvar-uses var)))
 380         (/noshow var-node (ref-p var-node))
 381         (when (ref-p var-node)
 382           (propagate-to-refs (ref-leaf var-node)
 383                              (specifier-type
 384                               (compute-alien-rep-type
 385                                (local-alien-info-type info))))))))
 386   nil)
 387
 388 (deftransform local-alien ((info var) * * :important t)
 389   (unless (constant-lvar-p info)
 390     (abort-ir1-transform "Local alien info isn't constant?"))
 391   (let* ((info (lvar-value info))
 392          (alien-type (local-alien-info-type info)))
 393     (/noshow "in DEFTRANSFORM LOCAL-ALIEN" info alien-type)
 394     (/noshow (local-alien-info-force-to-memory-p info))
 395     (if (local-alien-info-force-to-memory-p info)
 396         `(extract-alien-value var 0 ',alien-type)
 397         `(naturalize var ',alien-type))))
 398
 399 (deftransform %local-alien-forced-to-memory-p ((info) * * :important t)
 400   (unless (constant-lvar-p info)
 401     (abort-ir1-transform "Local alien info isn't constant?"))
 402   (let ((info (lvar-value info)))
 403     (local-alien-info-force-to-memory-p info)))
 404
 405 (deftransform %set-local-alien ((info var value) * * :important t)
 406   (unless (constant-lvar-p info)
 407     (abort-ir1-transform "Local alien info isn't constant?"))
 408   (let* ((info (lvar-value info))
 409          (alien-type (local-alien-info-type info)))
 410     (if (local-alien-info-force-to-memory-p info)
 411         `(deposit-alien-value var 0 ',alien-type value)
 412         '(error "This should be eliminated as dead code."))))
 413
 414 (defoptimizer (%local-alien-addr derive-type) ((info var))
 415   (if (constant-lvar-p info)
 416       (let* ((info (lvar-value info))
 417              (alien-type (local-alien-info-type info)))
 418         (make-alien-type-type (make-alien-pointer-type :to alien-type)))
 419       *wild-type*))
 420
 421 (deftransform %local-alien-addr ((info var) * * :important t)
 422   (unless (constant-lvar-p info)
 423     (abort-ir1-transform "Local alien info isn't constant?"))
 424   (let* ((info (lvar-value info))
 425          (alien-type (local-alien-info-type info)))
 426     (/noshow "in DEFTRANSFORM %LOCAL-ALIEN-ADDR, creating %SAP-ALIEN")
 427     (if (local-alien-info-force-to-memory-p info)
 428         `(%sap-alien var ',(make-alien-pointer-type :to alien-type))
 429         (error "This shouldn't happen."))))
 430
 431 (deftransform dispose-local-alien ((info var) * * :important t)
 432   (unless (constant-lvar-p info)
 433     (abort-ir1-transform "Local alien info isn't constant?"))
 434   (let* ((info (lvar-value info))
 435          (alien-type (local-alien-info-type info)))
 436     (if (local-alien-info-force-to-memory-p info)
 437       #!+x86 `(%primitive dealloc-alien-stack-space
 438                           ,(ceiling (alien-type-bits alien-type)
 439                                     sb!vm:n-byte-bits))
 440       #!-x86 `(%primitive dealloc-number-stack-space
 441                           ,(ceiling (alien-type-bits alien-type)
 442                                     sb!vm:n-byte-bits))
 443       nil)))
 444 \f
 445 ;;;; %CAST
 446
 447 (defoptimizer (%cast derive-type) ((alien type))
 448   (or (when (constant-lvar-p type)
 449         (let ((alien-type (lvar-value type)))
 450           (when (alien-type-p alien-type)
 451             (make-alien-type-type alien-type))))
 452       *wild-type*))
 453
 454 (deftransform %cast ((alien target-type) * * :important t)
 455   (unless (constant-lvar-p target-type)
 456     (give-up-ir1-transform
 457      "The alien type is not constant, so access cannot be open coded."))
 458   (let ((target-type (lvar-value target-type)))
 459     (cond ((or (alien-pointer-type-p target-type)
 460                (alien-array-type-p target-type)
 461                (alien-fun-type-p target-type))
 462            `(naturalize (alien-sap alien) ',target-type))
 463           (t
 464            (abort-ir1-transform "cannot cast to alien type ~S" target-type)))))
 465 \f
 466 ;;;; ALIEN-SAP, %SAP-ALIEN, %ADDR, etc.
 467
 468 (deftransform alien-sap ((alien) * * :important t)
 469   (let ((alien-node (lvar-uses alien)))
 470     (typecase alien-node
 471       (combination
 472        (extract-fun-args alien '%sap-alien 2)
 473        '(lambda (sap type)
 474           (declare (ignore type))
 475           sap))
 476       (t
 477        (give-up-ir1-transform)))))
 478
 479 (defoptimizer (%sap-alien derive-type) ((sap type))
 480   (declare (ignore sap))
 481   (if (constant-lvar-p type)
 482       (make-alien-type-type (lvar-value type))
 483       *wild-type*))
 484
 485 (deftransform %sap-alien ((sap type) * * :important t)
 486   (give-up-ir1-transform
 487    ;; FIXME: The hardcoded newline here causes more-than-usually
 488    ;; screwed-up formatting of the optimization note output.
 489    "could not optimize away %SAP-ALIEN: forced to do runtime ~@
 490     allocation of alien-value structure"))
 491 \f
 492 ;;;; NATURALIZE/DEPORT/EXTRACT/DEPOSIT magic
 493
 494 (flet ((%computed-lambda (compute-lambda type)
 495          (declare (type function compute-lambda))
 496          (unless (constant-lvar-p type)
 497            (give-up-ir1-transform
 498             "The type is not constant at compile time; can't open code."))
 499          (handler-case
 500              (let ((result (funcall compute-lambda (lvar-value type))))
 501                (/noshow "in %COMPUTED-LAMBDA" (lvar-value type) result)
 502                result)
 503            (error (condition)
 504                   (compiler-error "~A" condition)))))
 505   (deftransform naturalize ((object type) * * :important t)
 506     (%computed-lambda #'compute-naturalize-lambda type))
 507   (deftransform deport ((alien type) * * :important t)
 508     (%computed-lambda #'compute-deport-lambda type))
 509   (deftransform extract-alien-value ((sap offset type) * * :important t)
 510     (%computed-lambda #'compute-extract-lambda type))
 511   (deftransform deposit-alien-value ((sap offset type value) * * :important t)
 512     (%computed-lambda #'compute-deposit-lambda type)))
 513 \f
 514 ;;;; a hack to clean up divisions
 515
 516 (defun count-low-order-zeros (thing)
 517   (typecase thing
 518     (lvar
 519      (if (constant-lvar-p thing)
 520          (count-low-order-zeros (lvar-value thing))
 521          (count-low-order-zeros (lvar-uses thing))))
 522     (combination
 523      (case (let ((name (lvar-fun-name (combination-fun thing))))
 524              (or (modular-version-info name) name))
 525        ((+ -)
 526         (let ((min most-positive-fixnum)
 527               (itype (specifier-type 'integer)))
 528           (dolist (arg (combination-args thing) min)
 529             (if (csubtypep (lvar-type arg) itype)
 530                 (setf min (min min (count-low-order-zeros arg)))
 531                 (return 0)))))
 532        (*
 533         (let ((result 0)
 534               (itype (specifier-type 'integer)))
 535           (dolist (arg (combination-args thing) result)
 536             (if (csubtypep (lvar-type arg) itype)
 537                 (setf result (+ result (count-low-order-zeros arg)))
 538                 (return 0)))))
 539        (ash
 540         (let ((args (combination-args thing)))
 541           (if (= (length args) 2)
 542               (let ((amount (second args)))
 543                 (if (constant-lvar-p amount)
 544                     (max (+ (count-low-order-zeros (first args))
 545                             (lvar-value amount))
 546                          0)
 547                     0))
 548               0)))
 549        (t
 550         0)))
 551     (integer
 552      (if (zerop thing)
 553          most-positive-fixnum
 554          (do ((result 0 (1+ result))
 555               (num thing (ash num -1)))
 556              ((logbitp 0 num) result))))
 557     (cast
 558      (count-low-order-zeros (cast-value thing)))
 559     (t
 560      0)))
 561
 562 (deftransform / ((numerator denominator) (integer integer))
 563   "convert x/2^k to shift"
 564   (unless (constant-lvar-p denominator)
 565     (give-up-ir1-transform))
 566   (let* ((denominator (lvar-value denominator))
 567          (bits (1- (integer-length denominator))))
 568     (unless (and (> denominator 0) (= (ash 1 bits) denominator))
 569       (give-up-ir1-transform))
 570     (let ((alignment (count-low-order-zeros numerator)))
 571       (unless (>= alignment bits)
 572         (give-up-ir1-transform))
 573       `(ash numerator ,(- bits)))))
 574
 575 (deftransform ash ((value amount))
 576   (let ((value-node (lvar-uses value)))
 577     (unless (combination-p value-node)
 578       (give-up-ir1-transform))
 579     (let ((inside-fun-name (lvar-fun-name (combination-fun value-node))))
 580       (multiple-value-bind (prototype width)
 581           (modular-version-info inside-fun-name)
 582         (unless (eq (or prototype inside-fun-name) 'ash)
 583           (give-up-ir1-transform))
 584         (when (and width (not (constant-lvar-p amount)))
 585           (give-up-ir1-transform))
 586         (let ((inside-args (combination-args value-node)))
 587           (unless (= (length inside-args) 2)
 588             (give-up-ir1-transform))
 589           (let ((inside-amount (second inside-args)))
 590             (unless (and (constant-lvar-p inside-amount)
 591                          (not (minusp (lvar-value inside-amount))))
 592               (give-up-ir1-transform)))
 593           (extract-fun-args value inside-fun-name 2)
 594           (if width
 595               `(lambda (value amount1 amount2)
 596                  (logand (ash value (+ amount1 amount2))
 597                          ,(1- (ash 1 (+ width (lvar-value amount))))))
 598               `(lambda (value amount1 amount2)
 599                  (ash value (+ amount1 amount2)))))))))
 600 \f
 601 ;;;; ALIEN-FUNCALL support
 602
 603 (deftransform alien-funcall ((function &rest args)
 604                              ((alien (* t)) &rest *) *
 605                              :important t)
 606   (let ((names (make-gensym-list (length args))))
 607     (/noshow "entering first DEFTRANSFORM ALIEN-FUNCALL" function args)
 608     `(lambda (function ,@names)
 609        (alien-funcall (deref function) ,@names))))
 610
 611 (deftransform alien-funcall ((function &rest args) * * :important t)
 612   (let ((type (lvar-type function)))
 613     (unless (alien-type-type-p type)
 614       (give-up-ir1-transform "can't tell function type at compile time"))
 615     (/noshow "entering second DEFTRANSFORM ALIEN-FUNCALL" function)
 616     (let ((alien-type (alien-type-type-alien-type type)))
 617       (unless (alien-fun-type-p alien-type)
 618         (give-up-ir1-transform))
 619       (let ((arg-types (alien-fun-type-arg-types alien-type)))
 620         (unless (= (length args) (length arg-types))
 621           (abort-ir1-transform
 622            "wrong number of arguments; expected ~W, got ~W"
 623            (length arg-types)
 624            (length args)))
 625         (collect ((params) (deports))
 626           (dolist (arg-type arg-types)
 627             (let ((param (gensym)))
 628               (params param)
 629               (deports `(deport ,param ',arg-type))))
 630           (let ((return-type (alien-fun-type-result-type alien-type))
 631                 (body `(%alien-funcall (deport function ',alien-type)
 632                                        ',alien-type
 633                                        ,@(deports))))
 634             (if (alien-values-type-p return-type)
 635                 (collect ((temps) (results))
 636                   (dolist (type (alien-values-type-values return-type))
 637                     (let ((temp (gensym)))
 638                       (temps temp)
 639                       (results `(naturalize ,temp ',type))))
 640                   (setf body
 641                         `(multiple-value-bind ,(temps) ,body
 642                            (values ,@(results)))))
 643                 (setf body `(naturalize ,body ',return-type)))
 644             (/noshow "returning from DEFTRANSFORM ALIEN-FUNCALL" (params) body)
 645             `(lambda (function ,@(params))
 646                ,body)))))))
 647
 648 (defoptimizer (%alien-funcall derive-type) ((function type &rest args))
 649   (declare (ignore function args))
 650   (unless (constant-lvar-p type)
 651     (error "Something is broken."))
 652   (let ((type (lvar-value type)))
 653     (unless (alien-fun-type-p type)
 654       (error "Something is broken."))
 655     (values-specifier-type
 656      (compute-alien-rep-type
 657       (alien-fun-type-result-type type)))))
 658
 659 (defoptimizer (%alien-funcall ltn-annotate)
 660               ((function type &rest args) node ltn-policy)
 661   (setf (basic-combination-info node) :funny)
 662   (setf (node-tail-p node) nil)
 663   (annotate-ordinary-lvar function)
 664   (dolist (arg args)
 665     (annotate-ordinary-lvar arg)))
 666
 667 (defoptimizer (%alien-funcall ir2-convert)
 668               ((function type &rest args) call block)
 669   (let ((type (if (constant-lvar-p type)
 670                   (lvar-value type)
 671                   (error "Something is broken.")))
 672         (lvar (node-lvar call))
 673         (args args))
 674     (multiple-value-bind (nsp stack-frame-size arg-tns result-tns)
 675         (make-call-out-tns type)
 676       (vop alloc-number-stack-space call block stack-frame-size nsp)
 677       (dolist (tn arg-tns)
 678         (let* ((arg (pop args))
 679                (sc (tn-sc tn))
 680                (scn (sc-number sc))
 681                #!-x86 (temp-tn (make-representation-tn (tn-primitive-type tn)
 682                                                        scn))
 683                (move-arg-vops (svref (sc-move-arg-vops sc) scn)))
 684           (aver arg)
 685           (unless (= (length move-arg-vops) 1)
 686             (error "no unique move-arg-vop for moves in SC ~S" (sc-name sc)))
 687           #!+x86 (emit-move-arg-template call
 688                                          block
 689                                          (first move-arg-vops)
 690                                          (lvar-tn call block arg)
 691                                          nsp
 692                                          tn)
 693           #!-x86 (progn
 694                    (emit-move call
 695                               block
 696                               (lvar-tn call block arg)
 697                               temp-tn)
 698                    (emit-move-arg-template call
 699                                            block
 700                                            (first move-arg-vops)
 701                                            temp-tn
 702                                            nsp
 703                                            tn))))
 704       (aver (null args))
 705       (unless (listp result-tns)
 706         (setf result-tns (list result-tns)))
 707       (vop* call-out call block
 708             ((lvar-tn call block function)
 709              (reference-tn-list arg-tns nil))
 710             ((reference-tn-list result-tns t)))
 711       (vop dealloc-number-stack-space call block stack-frame-size)
 712       (move-lvar-result call block result-tns lvar))))