1 ;;;; This file contains miscellaneous utilities used for manipulating
2 ;;;; the IR1 representation.
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
17 ;;; Return the innermost cleanup enclosing NODE, or NIL if there is
18 ;;; none in its function. If NODE has no cleanup, but is in a LET,
19 ;;; then we must still check the environment that the call is in.
20 (defun node-enclosing-cleanup (node)
21 (declare (type node node))
22 (do ((lexenv (node-lexenv node)
23 (lambda-call-lexenv (lexenv-lambda lexenv))))
25 (let ((cup (lexenv-cleanup lexenv)))
26 (when cup (return cup)))))
28 ;;; Convert the FORM in a block inserted between BLOCK1 and BLOCK2 as
29 ;;; an implicit MV-PROG1. The inserted block is returned. NODE is used
30 ;;; for IR1 context when converting the form. Note that the block is
31 ;;; not assigned a number, and is linked into the DFO at the
32 ;;; beginning. We indicate that we have trashed the DFO by setting
33 ;;; COMPONENT-REANALYZE. If CLEANUP is supplied, then convert with
35 (defun insert-cleanup-code (block1 block2 node form &optional cleanup)
36 (declare (type cblock block1 block2) (type node node)
37 (type (or cleanup null) cleanup))
38 (setf (component-reanalyze (block-component block1)) t)
39 (with-ir1-environment-from-node node
40 (with-component-last-block (*current-component*
41 (block-next (component-head *current-component*)))
42 (let* ((start (make-ctran))
43 (block (ctran-starts-block start))
46 (make-lexenv :cleanup cleanup)
48 (change-block-successor block1 block2 block)
49 (link-blocks block block2)
50 (ir1-convert start next nil form)
51 (setf (block-last block) (ctran-use next))
52 (setf (node-next (block-last block)) nil)
57 ;;; Return a list of all the nodes which use LVAR.
58 (declaim (ftype (sfunction (lvar) list) find-uses))
59 (defun find-uses (lvar)
60 (let ((uses (lvar-uses lvar)))
65 (defun principal-lvar-use (lvar)
66 (let ((use (lvar-uses lvar)))
68 (principal-lvar-use (cast-value use))
71 ;;; Update lvar use information so that NODE is no longer a use of its
74 ;;; Note: if you call this function, you may have to do a
75 ;;; REOPTIMIZE-LVAR to inform IR1 optimization that something has
77 (declaim (ftype (sfunction (node) (values))
80 ;;; Just delete NODE from its LVAR uses; LVAR is preserved so it may
81 ;;; be given a new use.
82 (defun %delete-lvar-use (node)
83 (let ((lvar (node-lvar node)))
85 (if (listp (lvar-uses lvar))
86 (let ((new-uses (delq node (lvar-uses lvar))))
87 (setf (lvar-uses lvar)
88 (if (singleton-p new-uses)
91 (setf (lvar-uses lvar) nil))
92 (setf (node-lvar node) nil)))
94 ;;; Delete NODE from its LVAR uses; if LVAR has no other uses, delete
95 ;;; its DEST's block, which must be unreachable.
96 (defun delete-lvar-use (node)
97 (let ((lvar (node-lvar node)))
99 (%delete-lvar-use node)
100 (if (null (lvar-uses lvar))
101 (binding* ((dest (lvar-dest lvar) :exit-if-null)
102 (() (not (node-deleted dest)) :exit-if-null)
103 (block (node-block dest)))
104 (mark-for-deletion block))
105 (reoptimize-lvar lvar))))
108 ;;; Update lvar use information so that NODE uses LVAR.
110 ;;; Note: if you call this function, you may have to do a
111 ;;; REOPTIMIZE-LVAR to inform IR1 optimization that something has
113 (declaim (ftype (sfunction (node (or lvar null)) (values)) add-lvar-use))
114 (defun add-lvar-use (node lvar)
115 (aver (not (node-lvar node)))
117 (let ((uses (lvar-uses lvar)))
118 (setf (lvar-uses lvar)
125 (setf (node-lvar node) lvar)))
129 ;;; Return true if LVAR destination is executed immediately after
130 ;;; NODE. Cleanups are ignored.
131 (defun immediately-used-p (lvar node)
132 (declare (type lvar lvar) (type node node))
133 (aver (eq (node-lvar node) lvar))
134 (let ((dest (lvar-dest lvar)))
135 (acond ((node-next node)
136 (eq (ctran-next it) dest))
137 (t (eq (block-start (first (block-succ (node-block node))))
138 (node-prev dest))))))
140 ;;;; lvar substitution
142 ;;; In OLD's DEST, replace OLD with NEW. NEW's DEST must initially be
143 ;;; NIL. We do not flush OLD's DEST.
144 (defun substitute-lvar (new old)
145 (declare (type lvar old new))
146 (aver (not (lvar-dest new)))
147 (let ((dest (lvar-dest old)))
150 (cif (setf (if-test dest) new))
151 (cset (setf (set-value dest) new))
152 (creturn (setf (return-result dest) new))
153 (exit (setf (exit-value dest) new))
155 (if (eq old (basic-combination-fun dest))
156 (setf (basic-combination-fun dest) new)
157 (setf (basic-combination-args dest)
158 (nsubst new old (basic-combination-args dest)))))
159 (cast (setf (cast-value dest) new)))
161 (setf (lvar-dest old) nil)
162 (setf (lvar-dest new) dest)
163 (flush-lvar-externally-checkable-type new))
166 ;;; Replace all uses of OLD with uses of NEW, where NEW has an
167 ;;; arbitary number of uses.
168 (defun substitute-lvar-uses (new old)
169 (declare (type lvar old)
170 (type (or lvar null) new))
172 (cond (new (do-uses (node old)
173 (%delete-lvar-use node)
174 (add-lvar-use node new))
175 (reoptimize-lvar new))
176 (t (flush-dest old)))
179 ;;;; block starting/creation
181 ;;; Return the block that CTRAN is the start of, making a block if
182 ;;; necessary. This function is called by IR1 translators which may
183 ;;; cause a CTRAN to be used more than once. Every CTRAN which may be
184 ;;; used more than once must start a block by the time that anyone
185 ;;; does a USE-CTRAN on it.
187 ;;; We also throw the block into the next/prev list for the
188 ;;; *CURRENT-COMPONENT* so that we keep track of which blocks we have
190 (defun ctran-starts-block (ctran)
191 (declare (type ctran ctran))
192 (ecase (ctran-kind ctran)
194 (aver (not (ctran-block ctran)))
195 (let* ((next (component-last-block *current-component*))
196 (prev (block-prev next))
197 (new-block (make-block ctran)))
198 (setf (block-next new-block) next
199 (block-prev new-block) prev
200 (block-prev next) new-block
201 (block-next prev) new-block
202 (ctran-block ctran) new-block
203 (ctran-kind ctran) :block-start)
204 (aver (not (ctran-use ctran)))
207 (ctran-block ctran))))
209 ;;; Ensure that CTRAN is the start of a block so that the use set can
210 ;;; be freely manipulated.
211 (defun ensure-block-start (ctran)
212 (declare (type ctran ctran))
213 (let ((kind (ctran-kind ctran)))
217 (setf (ctran-block ctran)
218 (make-block-key :start ctran))
219 (setf (ctran-kind ctran) :block-start))
221 (node-ends-block (ctran-use ctran)))))
226 ;;; Filter values of LVAR through FORM, which must be an ordinary/mv
227 ;;; call. First argument must be 'DUMMY, which will be replaced with
228 ;;; LVAR. In case of an ordinary call the function should not have
229 ;;; return type NIL. We create a new "filtered" lvar.
231 ;;; TODO: remove preconditions.
232 (defun filter-lvar (lvar form)
233 (declare (type lvar lvar) (type list form))
234 (let* ((dest (lvar-dest lvar))
235 (ctran (node-prev dest)))
236 (with-ir1-environment-from-node dest
238 (ensure-block-start ctran)
239 (let* ((old-block (ctran-block ctran))
240 (new-start (make-ctran))
241 (filtered-lvar (make-lvar))
242 (new-block (ctran-starts-block new-start)))
244 ;; Splice in the new block before DEST, giving the new block
245 ;; all of DEST's predecessors.
246 (dolist (block (block-pred old-block))
247 (change-block-successor block old-block new-block))
249 (ir1-convert new-start ctran filtered-lvar form)
251 ;; KLUDGE: Comments at the head of this function in CMU CL
252 ;; said that somewhere in here we
253 ;; Set the new block's start and end cleanups to the *start*
254 ;; cleanup of PREV's block. This overrides the incorrect
255 ;; default from WITH-IR1-ENVIRONMENT-FROM-NODE.
256 ;; Unfortunately I can't find any code which corresponds to this.
257 ;; Perhaps it was a stale comment? Or perhaps I just don't
258 ;; understand.. -- WHN 19990521
260 ;; Replace 'DUMMY with the LVAR. (We can find 'DUMMY because
261 ;; no LET conversion has been done yet.) The [mv-]combination
262 ;; code from the call in the form will be the use of the new
263 ;; check lvar. We substitute for the first argument of
265 (let* ((node (lvar-use filtered-lvar))
266 (args (basic-combination-args node))
267 (victim (first args)))
268 (aver (eq (constant-value (ref-leaf (lvar-use victim)))
271 (substitute-lvar filtered-lvar lvar)
272 (substitute-lvar lvar victim)
275 ;; Invoking local call analysis converts this call to a LET.
276 (locall-analyze-component *current-component*))))
279 ;;; Delete NODE and VALUE. It may result in some calls becoming tail.
280 (defun delete-filter (node lvar value)
281 (aver (eq (lvar-dest value) node))
282 (aver (eq (node-lvar node) lvar))
283 (cond (lvar (collect ((merges))
284 (when (return-p (lvar-dest lvar))
286 (when (and (basic-combination-p use)
287 (eq (basic-combination-kind use) :local))
289 (%delete-lvar-use node)
290 (substitute-lvar-uses lvar value)
293 (dolist (merge (merges))
294 (merge-tail-sets merge)))))
295 (t (flush-dest value)
296 (unlink-node node))))
298 ;;;; miscellaneous shorthand functions
300 ;;; Return the home (i.e. enclosing non-LET) CLAMBDA for NODE. Since
301 ;;; the LEXENV-LAMBDA may be deleted, we must chain up the
302 ;;; LAMBDA-CALL-LEXENV thread until we find a CLAMBDA that isn't
303 ;;; deleted, and then return its home.
304 (defun node-home-lambda (node)
305 (declare (type node node))
306 (do ((fun (lexenv-lambda (node-lexenv node))
307 (lexenv-lambda (lambda-call-lexenv fun))))
308 ((not (memq (functional-kind fun) '(:deleted :zombie)))
310 (when (eq (lambda-home fun) fun)
313 #!-sb-fluid (declaim (inline node-block))
314 (defun node-block (node)
315 (ctran-block (node-prev node)))
316 (declaim (ftype (sfunction (node) component) node-component))
317 (defun node-component (node)
318 (block-component (node-block node)))
319 (declaim (ftype (sfunction (node) physenv) node-physenv))
320 (defun node-physenv (node)
321 (lambda-physenv (node-home-lambda node)))
322 #!-sb-fluid (declaim (inline node-dest))
323 (defun node-dest (node)
324 (awhen (node-lvar node) (lvar-dest it)))
326 (declaim (inline block-to-be-deleted-p))
327 (defun block-to-be-deleted-p (block)
328 (or (block-delete-p block)
329 (eq (functional-kind (block-home-lambda block)) :deleted)))
331 ;;; Checks whether NODE is in a block to be deleted
332 (declaim (inline node-to-be-deleted-p))
333 (defun node-to-be-deleted-p (node)
334 (block-to-be-deleted-p (node-block node)))
336 (declaim (ftype (sfunction (clambda) cblock) lambda-block))
337 (defun lambda-block (clambda)
338 (node-block (lambda-bind clambda)))
339 (declaim (ftype (sfunction (clambda) component) lambda-component))
340 (defun lambda-component (clambda)
341 (block-component (lambda-block clambda)))
343 (declaim (ftype (sfunction (cblock) node) block-start-node))
344 (defun block-start-node (block)
345 (ctran-next (block-start block)))
347 ;;; Return the enclosing cleanup for environment of the first or last
349 (defun block-start-cleanup (block)
350 (node-enclosing-cleanup (block-start-node block)))
351 (defun block-end-cleanup (block)
352 (node-enclosing-cleanup (block-last block)))
354 ;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
355 ;;; if there is none.
357 ;;; There can legitimately be no home lambda in dead code early in the
358 ;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
359 ;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
360 ;;; where the block is just a placeholder during parsing and doesn't
361 ;;; actually correspond to code which will be written anywhere.
362 (declaim (ftype (sfunction (cblock) (or clambda null)) block-home-lambda-or-null))
363 (defun block-home-lambda-or-null (block)
364 (if (node-p (block-last block))
365 ;; This is the old CMU CL way of doing it.
366 (node-home-lambda (block-last block))
367 ;; Now that SBCL uses this operation more aggressively than CMU
368 ;; CL did, the old CMU CL way of doing it can fail in two ways.
369 ;; 1. It can fail in a few cases even when a meaningful home
370 ;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
372 ;; 2. It can fail when converting a form which is born orphaned
373 ;; so that it never had a meaningful home lambda, e.g. a form
374 ;; which follows a RETURN-FROM or GO form.
375 (let ((pred-list (block-pred block)))
376 ;; To deal with case 1, we reason that
377 ;; previous-in-target-execution-order blocks should be in the
378 ;; same lambda, and that they seem in practice to be
379 ;; previous-in-compilation-order blocks too, so we look back
380 ;; to find one which is sufficiently initialized to tell us
381 ;; what the home lambda is.
383 ;; We could get fancy about this, flooding through the
384 ;; graph of all the previous blocks, but in practice it
385 ;; seems to work just to grab the first previous block and
387 (node-home-lambda (block-last (first pred-list)))
388 ;; In case 2, we end up with an empty PRED-LIST and
389 ;; have to punt: There's no home lambda.
392 ;;; Return the non-LET LAMBDA that holds BLOCK's code.
393 (declaim (ftype (sfunction (cblock) clambda) block-home-lambda))
394 (defun block-home-lambda (block)
395 (block-home-lambda-or-null block))
397 ;;; Return the IR1 physical environment for BLOCK.
398 (declaim (ftype (sfunction (cblock) physenv) block-physenv))
399 (defun block-physenv (block)
400 (lambda-physenv (block-home-lambda block)))
402 ;;; Return the Top Level Form number of PATH, i.e. the ordinal number
403 ;;; of its original source's top level form in its compilation unit.
404 (defun source-path-tlf-number (path)
405 (declare (list path))
408 ;;; Return the (reversed) list for the PATH in the original source
409 ;;; (with the Top Level Form number last).
410 (defun source-path-original-source (path)
411 (declare (list path) (inline member))
412 (cddr (member 'original-source-start path :test #'eq)))
414 ;;; Return the Form Number of PATH's original source inside the Top
415 ;;; Level Form that contains it. This is determined by the order that
416 ;;; we walk the subforms of the top level source form.
417 (defun source-path-form-number (path)
418 (declare (list path) (inline member))
419 (cadr (member 'original-source-start path :test #'eq)))
421 ;;; Return a list of all the enclosing forms not in the original
422 ;;; source that converted to get to this form, with the immediate
423 ;;; source for node at the start of the list.
424 (defun source-path-forms (path)
425 (subseq path 0 (position 'original-source-start path)))
427 ;;; Return the innermost source form for NODE.
428 (defun node-source-form (node)
429 (declare (type node node))
430 (let* ((path (node-source-path node))
431 (forms (source-path-forms path)))
434 (values (find-original-source path)))))
436 ;;; Return NODE-SOURCE-FORM, T if lvar has a single use, otherwise
438 (defun lvar-source (lvar)
439 (let ((use (lvar-uses lvar)))
442 (values (node-source-form use) t))))
444 ;;; Return the unique node, delivering a value to LVAR.
445 #!-sb-fluid (declaim (inline lvar-use))
446 (defun lvar-use (lvar)
447 (the (not list) (lvar-uses lvar)))
449 #!-sb-fluid (declaim (inline lvar-has-single-use-p))
450 (defun lvar-has-single-use-p (lvar)
451 (typep (lvar-uses lvar) '(not list)))
453 ;;; Return the LAMBDA that is CTRAN's home, or NIL if there is none.
454 (declaim (ftype (sfunction (ctran) (or clambda null))
455 ctran-home-lambda-or-null))
456 (defun ctran-home-lambda-or-null (ctran)
457 ;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
458 ;; implementation might not be quite right, or might be uglier than
459 ;; necessary. It appears that the original Python never found a need
460 ;; to do this operation. The obvious things based on
461 ;; NODE-HOME-LAMBDA of CTRAN-USE usually work; then if that fails,
462 ;; BLOCK-HOME-LAMBDA of CTRAN-BLOCK works, given that we
463 ;; generalize it enough to grovel harder when the simple CMU CL
464 ;; approach fails, and furthermore realize that in some exceptional
465 ;; cases it might return NIL. -- WHN 2001-12-04
466 (cond ((ctran-use ctran)
467 (node-home-lambda (ctran-use ctran)))
469 (block-home-lambda-or-null (ctran-block ctran)))
471 (bug "confused about home lambda for ~S" ctran))))
473 ;;; Return the LAMBDA that is CTRAN's home.
474 (declaim (ftype (sfunction (ctran) clambda) ctran-home-lambda))
475 (defun ctran-home-lambda (ctran)
476 (ctran-home-lambda-or-null ctran))
478 #!-sb-fluid (declaim (inline lvar-single-value-p))
479 (defun lvar-single-value-p (lvar)
481 (let ((dest (lvar-dest lvar)))
486 (eq (basic-combination-fun dest) lvar))
489 (declare (notinline lvar-single-value-p))
490 (and (not (values-type-p (cast-asserted-type dest)))
491 (lvar-single-value-p (node-lvar dest)))))
495 (defun principal-lvar-end (lvar)
496 (loop for prev = lvar then (node-lvar dest)
497 for dest = (and prev (lvar-dest prev))
499 finally (return (values dest prev))))
501 (defun principal-lvar-single-valuify (lvar)
502 (loop for prev = lvar then (node-lvar dest)
503 for dest = (and prev (lvar-dest prev))
505 do (setf (node-derived-type dest)
506 (make-short-values-type (list (single-value-type
507 (node-derived-type dest)))))
508 (reoptimize-lvar prev)))
510 ;;; Return a new LEXENV just like DEFAULT except for the specified
511 ;;; slot values. Values for the alist slots are NCONCed to the
512 ;;; beginning of the current value, rather than replacing it entirely.
513 (defun make-lexenv (&key (default *lexenv*)
514 funs vars blocks tags
516 (lambda (lexenv-lambda default))
517 (cleanup (lexenv-cleanup default))
518 (policy (lexenv-policy default)))
519 (macrolet ((frob (var slot)
520 `(let ((old (,slot default)))
524 (internal-make-lexenv
525 (frob funs lexenv-funs)
526 (frob vars lexenv-vars)
527 (frob blocks lexenv-blocks)
528 (frob tags lexenv-tags)
529 (frob type-restrictions lexenv-type-restrictions)
530 lambda cleanup policy)))
532 ;;; Makes a LEXENV, suitable for using in a MACROLET introduced
534 (defun make-restricted-lexenv (lexenv)
535 (flet ((fun-good-p (fun)
536 (destructuring-bind (name . thing) fun
537 (declare (ignore name))
541 (cons (aver (eq (car thing) 'macro))
544 (destructuring-bind (name . thing) var
545 (declare (ignore name))
548 (cons (aver (eq (car thing) 'macro))
550 (heap-alien-info nil)))))
551 (internal-make-lexenv
552 (remove-if-not #'fun-good-p (lexenv-funs lexenv))
553 (remove-if-not #'var-good-p (lexenv-vars lexenv))
556 (lexenv-type-restrictions lexenv) ; XXX
559 (lexenv-policy lexenv))))
561 ;;;; flow/DFO/component hackery
563 ;;; Join BLOCK1 and BLOCK2.
564 (defun link-blocks (block1 block2)
565 (declare (type cblock block1 block2))
566 (setf (block-succ block1)
567 (if (block-succ block1)
568 (%link-blocks block1 block2)
570 (push block1 (block-pred block2))
572 (defun %link-blocks (block1 block2)
573 (declare (type cblock block1 block2))
574 (let ((succ1 (block-succ block1)))
575 (aver (not (memq block2 succ1)))
576 (cons block2 succ1)))
578 ;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
579 ;;; this leaves a successor with a single predecessor that ends in an
580 ;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
581 ;;; now be able to be propagated to the successor.
582 (defun unlink-blocks (block1 block2)
583 (declare (type cblock block1 block2))
584 (let ((succ1 (block-succ block1)))
585 (if (eq block2 (car succ1))
586 (setf (block-succ block1) (cdr succ1))
587 (do ((succ (cdr succ1) (cdr succ))
589 ((eq (car succ) block2)
590 (setf (cdr prev) (cdr succ)))
593 (let ((new-pred (delq block1 (block-pred block2))))
594 (setf (block-pred block2) new-pred)
595 (when (singleton-p new-pred)
596 (let ((pred-block (first new-pred)))
597 (when (if-p (block-last pred-block))
598 (setf (block-test-modified pred-block) t)))))
601 ;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
602 ;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
603 ;;; consequent/alternative blocks to point to NEW. We also set
604 ;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
605 ;;; the new successor.
606 (defun change-block-successor (block old new)
607 (declare (type cblock new old block))
608 (unlink-blocks block old)
609 (let ((last (block-last block))
610 (comp (block-component block)))
611 (setf (component-reanalyze comp) t)
614 (setf (block-test-modified block) t)
615 (let* ((succ-left (block-succ block))
616 (new (if (and (eq new (component-tail comp))
620 (unless (memq new succ-left)
621 (link-blocks block new))
622 (macrolet ((frob (slot)
623 `(when (eq (,slot last) old)
624 (setf (,slot last) new))))
626 (frob if-alternative)
627 (when (eq (if-consequent last)
628 (if-alternative last))
629 (setf (component-reoptimize (block-component block)) t)))))
631 (unless (memq new (block-succ block))
632 (link-blocks block new)))))
636 ;;; Unlink a block from the next/prev chain. We also null out the
638 (declaim (ftype (sfunction (cblock) (values)) remove-from-dfo))
639 (defun remove-from-dfo (block)
640 (let ((next (block-next block))
641 (prev (block-prev block)))
642 (setf (block-component block) nil)
643 (setf (block-next prev) next)
644 (setf (block-prev next) prev))
647 ;;; Add BLOCK to the next/prev chain following AFTER. We also set the
648 ;;; COMPONENT to be the same as for AFTER.
649 (defun add-to-dfo (block after)
650 (declare (type cblock block after))
651 (let ((next (block-next after))
652 (comp (block-component after)))
653 (aver (not (eq (component-kind comp) :deleted)))
654 (setf (block-component block) comp)
655 (setf (block-next after) block)
656 (setf (block-prev block) after)
657 (setf (block-next block) next)
658 (setf (block-prev next) block))
661 ;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
662 ;;; the head and tail which are set to T.
663 (declaim (ftype (sfunction (component) (values)) clear-flags))
664 (defun clear-flags (component)
665 (let ((head (component-head component))
666 (tail (component-tail component)))
667 (setf (block-flag head) t)
668 (setf (block-flag tail) t)
669 (do-blocks (block component)
670 (setf (block-flag block) nil)))
673 ;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
674 ;;; true in the head and tail blocks.
675 (declaim (ftype (sfunction () component) make-empty-component))
676 (defun make-empty-component ()
677 (let* ((head (make-block-key :start nil :component nil))
678 (tail (make-block-key :start nil :component nil))
679 (res (make-component head tail)))
680 (setf (block-flag head) t)
681 (setf (block-flag tail) t)
682 (setf (block-component head) res)
683 (setf (block-component tail) res)
684 (setf (block-next head) tail)
685 (setf (block-prev tail) head)
688 ;;; Make NODE the LAST node in its block, splitting the block if necessary.
689 ;;; The new block is added to the DFO immediately following NODE's block.
690 (defun node-ends-block (node)
691 (declare (type node node))
692 (let* ((block (node-block node))
693 (start (node-next node))
694 (last (block-last block)))
695 (unless (eq last node)
696 (aver (and (eq (ctran-kind start) :inside-block)
697 (not (block-delete-p block))))
698 (let* ((succ (block-succ block))
700 (make-block-key :start start
701 :component (block-component block)
702 :succ succ :last last)))
703 (setf (ctran-kind start) :block-start)
704 (setf (ctran-use start) nil)
705 (setf (block-last block) node)
706 (setf (node-next node) nil)
709 (cons new-block (remove block (block-pred b)))))
710 (setf (block-succ block) ())
711 (link-blocks block new-block)
712 (add-to-dfo new-block block)
713 (setf (component-reanalyze (block-component block)) t)
715 (do ((ctran start (node-next (ctran-next ctran))))
717 (setf (ctran-block ctran) new-block))
719 (setf (block-type-asserted block) t)
720 (setf (block-test-modified block) t))))
725 ;;; Deal with deleting the last (read) reference to a LAMBDA-VAR.
726 (defun delete-lambda-var (leaf)
727 (declare (type lambda-var leaf))
729 ;; Iterate over all local calls flushing the corresponding argument,
730 ;; allowing the computation of the argument to be deleted. We also
731 ;; mark the LET for reoptimization, since it may be that we have
732 ;; deleted its last variable.
733 (let* ((fun (lambda-var-home leaf))
734 (n (position leaf (lambda-vars fun))))
735 (dolist (ref (leaf-refs fun))
736 (let* ((lvar (node-lvar ref))
737 (dest (and lvar (lvar-dest lvar))))
738 (when (and (combination-p dest)
739 (eq (basic-combination-fun dest) lvar)
740 (eq (basic-combination-kind dest) :local))
741 (let* ((args (basic-combination-args dest))
743 (reoptimize-lvar arg)
745 (setf (elt args n) nil))))))
747 ;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
748 ;; too much difficulty, since we can efficiently implement
749 ;; write-only variables. We iterate over the SETs, marking their
750 ;; blocks for dead code flushing, since we can delete SETs whose
752 (dolist (set (lambda-var-sets leaf))
753 (setf (block-flush-p (node-block set)) t))
757 ;;; Note that something interesting has happened to VAR.
758 (defun reoptimize-lambda-var (var)
759 (declare (type lambda-var var))
760 (let ((fun (lambda-var-home var)))
761 ;; We only deal with LET variables, marking the corresponding
762 ;; initial value arg as needing to be reoptimized.
763 (when (and (eq (functional-kind fun) :let)
765 (do ((args (basic-combination-args
766 (lvar-dest (node-lvar (first (leaf-refs fun)))))
768 (vars (lambda-vars fun) (cdr vars)))
770 (reoptimize-lvar (car args))))))
773 ;;; Delete a function that has no references. This need only be called
774 ;;; on functions that never had any references, since otherwise
775 ;;; DELETE-REF will handle the deletion.
776 (defun delete-functional (fun)
777 (aver (and (null (leaf-refs fun))
778 (not (functional-entry-fun fun))))
780 (optional-dispatch (delete-optional-dispatch fun))
781 (clambda (delete-lambda fun)))
784 ;;; Deal with deleting the last reference to a CLAMBDA, which means
785 ;;; that the lambda is unreachable, so that its body may be
786 ;;; deleted. We set FUNCTIONAL-KIND to :DELETED and rely on
787 ;;; IR1-OPTIMIZE to delete its blocks.
788 (defun delete-lambda (clambda)
789 (declare (type clambda clambda))
790 (let ((original-kind (functional-kind clambda))
791 (bind (lambda-bind clambda)))
792 (aver (not (member original-kind '(:deleted :toplevel))))
793 (aver (not (functional-has-external-references-p clambda)))
794 (aver (or (eq original-kind :zombie) bind))
795 (setf (functional-kind clambda) :deleted)
796 (setf (lambda-bind clambda) nil)
798 (labels ((delete-children (lambda)
799 (dolist (child (lambda-children lambda))
800 (cond ((eq (functional-kind child) :deleted)
801 (delete-children child))
803 (delete-lambda child))))
804 (setf (lambda-children lambda) nil)
805 (setf (lambda-parent lambda) nil)))
806 (delete-children clambda))
808 ;; (The IF test is (FUNCTIONAL-SOMEWHAT-LETLIKE-P CLAMBDA), except
809 ;; that we're using the old value of the KIND slot, not the
810 ;; current slot value, which has now been set to :DELETED.)
813 ((:let :mv-let :assignment)
814 (let ((bind-block (node-block bind)))
815 (mark-for-deletion bind-block))
816 (let ((home (lambda-home clambda)))
817 (setf (lambda-lets home) (delete clambda (lambda-lets home))))
818 ;; KLUDGE: In presence of NLEs we cannot always understand that
819 ;; LET's BIND dominates its body [for a LET "its" body is not
820 ;; quite its]; let's delete too dangerous for IR2 stuff. --
822 (dolist (var (lambda-vars clambda))
823 (flet ((delete-node (node)
824 (mark-for-deletion (node-block node))))
825 (mapc #'delete-node (leaf-refs var))
826 (mapc #'delete-node (lambda-var-sets var)))))
828 ;; Function has no reachable references.
829 (dolist (ref (lambda-refs clambda))
830 (mark-for-deletion (node-block ref)))
831 ;; If the function isn't a LET, we unlink the function head
832 ;; and tail from the component head and tail to indicate that
833 ;; the code is unreachable. We also delete the function from
834 ;; COMPONENT-LAMBDAS (it won't be there before local call
835 ;; analysis, but no matter.) If the lambda was never
836 ;; referenced, we give a note.
837 (let* ((bind-block (node-block bind))
838 (component (block-component bind-block))
839 (return (lambda-return clambda))
840 (return-block (and return (node-block return))))
841 (unless (leaf-ever-used clambda)
842 (let ((*compiler-error-context* bind))
843 (compiler-notify 'code-deletion-note
844 :format-control "deleting unused function~:[.~;~:*~% ~S~]"
845 :format-arguments (list (leaf-debug-name clambda)))))
846 (unless (block-delete-p bind-block)
847 (unlink-blocks (component-head component) bind-block))
848 (when (and return-block (not (block-delete-p return-block)))
849 (mark-for-deletion return-block)
850 (unlink-blocks return-block (component-tail component)))
851 (setf (component-reanalyze component) t)
852 (let ((tails (lambda-tail-set clambda)))
853 (setf (tail-set-funs tails)
854 (delete clambda (tail-set-funs tails)))
855 (setf (lambda-tail-set clambda) nil))
856 (setf (component-lambdas component)
857 (delq clambda (component-lambdas component))))))
859 ;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
860 ;; ENTRY-FUN so that people will know that it is not an entry
862 (when (eq original-kind :external)
863 (let ((fun (functional-entry-fun clambda)))
864 (setf (functional-entry-fun fun) nil)
865 (when (optional-dispatch-p fun)
866 (delete-optional-dispatch fun)))))
870 ;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
871 ;;; have to be a bit more careful than with lambdas, since DELETE-REF
872 ;;; is used both before and after local call analysis. Afterward, all
873 ;;; references to still-existing OPTIONAL-DISPATCHes have been moved
874 ;;; to the XEP, leaving it with no references at all. So we look at
875 ;;; the XEP to see whether an optional-dispatch is still really being
876 ;;; used. But before local call analysis, there are no XEPs, and all
877 ;;; references are direct.
879 ;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
880 ;;; entry-points, making them be normal lambdas, and then deleting the
881 ;;; ones with no references. This deletes any e-p lambdas that were
882 ;;; either never referenced, or couldn't be deleted when the last
883 ;;; reference was deleted (due to their :OPTIONAL kind.)
885 ;;; Note that the last optional entry point may alias the main entry,
886 ;;; so when we process the main entry, its KIND may have been changed
887 ;;; to NIL or even converted to a LETlike value.
888 (defun delete-optional-dispatch (leaf)
889 (declare (type optional-dispatch leaf))
890 (let ((entry (functional-entry-fun leaf)))
891 (unless (and entry (leaf-refs entry))
892 (aver (or (not entry) (eq (functional-kind entry) :deleted)))
893 (setf (functional-kind leaf) :deleted)
896 (unless (eq (functional-kind fun) :deleted)
897 (aver (eq (functional-kind fun) :optional))
898 (setf (functional-kind fun) nil)
899 (let ((refs (leaf-refs fun)))
903 (or (maybe-let-convert fun)
904 (maybe-convert-to-assignment fun)))
906 (maybe-convert-to-assignment fun)))))))
908 (dolist (ep (optional-dispatch-entry-points leaf))
909 (when (promise-ready-p ep)
911 (when (optional-dispatch-more-entry leaf)
912 (frob (optional-dispatch-more-entry leaf)))
913 (let ((main (optional-dispatch-main-entry leaf)))
914 (when (eq (functional-kind main) :optional)
919 ;;; Do stuff to delete the semantic attachments of a REF node. When
920 ;;; this leaves zero or one reference, we do a type dispatch off of
921 ;;; the leaf to determine if a special action is appropriate.
922 (defun delete-ref (ref)
923 (declare (type ref ref))
924 (let* ((leaf (ref-leaf ref))
925 (refs (delq ref (leaf-refs leaf))))
926 (setf (leaf-refs leaf) refs)
931 (delete-lambda-var leaf))
933 (ecase (functional-kind leaf)
934 ((nil :let :mv-let :assignment :escape :cleanup)
935 (aver (null (functional-entry-fun leaf)))
936 (delete-lambda leaf))
938 (delete-lambda leaf))
939 ((:deleted :zombie :optional))))
941 (unless (eq (functional-kind leaf) :deleted)
942 (delete-optional-dispatch leaf)))))
945 (clambda (or (maybe-let-convert leaf)
946 (maybe-convert-to-assignment leaf)))
947 (lambda-var (reoptimize-lambda-var leaf))))
950 (clambda (maybe-convert-to-assignment leaf))))))
954 ;;; This function is called by people who delete nodes; it provides a
955 ;;; way to indicate that the value of a lvar is no longer used. We
956 ;;; null out the LVAR-DEST, set FLUSH-P in the blocks containing uses
957 ;;; of LVAR and set COMPONENT-REOPTIMIZE.
958 (defun flush-dest (lvar)
959 (declare (type (or lvar null) lvar))
961 (setf (lvar-dest lvar) nil)
962 (flush-lvar-externally-checkable-type lvar)
964 (let ((prev (node-prev use)))
965 (let ((block (ctran-block prev)))
966 (setf (component-reoptimize (block-component block)) t)
967 (setf (block-attributep (block-flags block)
968 flush-p type-asserted type-check)
970 (setf (node-lvar use) nil))
971 (setf (lvar-uses lvar) nil))
974 (defun delete-dest (lvar)
976 (let* ((dest (lvar-dest lvar))
977 (prev (node-prev dest)))
978 (let ((block (ctran-block prev)))
979 (unless (block-delete-p block)
980 (mark-for-deletion block))))))
982 ;;; Queue the block for deletion
983 (defun delete-block-lazily (block)
984 (declare (type cblock block))
985 (unless (block-delete-p block)
986 (setf (block-delete-p block) t)
987 (push block (component-delete-blocks (block-component block)))))
989 ;;; Do a graph walk backward from BLOCK, marking all predecessor
990 ;;; blocks with the DELETE-P flag.
991 (defun mark-for-deletion (block)
992 (declare (type cblock block))
993 (let* ((component (block-component block))
994 (head (component-head component)))
995 (labels ((helper (block)
996 (delete-block-lazily block)
997 (dolist (pred (block-pred block))
998 (unless (or (block-delete-p pred)
1001 (unless (block-delete-p block)
1003 (setf (component-reanalyze component) t))))
1006 ;;; This function does what is necessary to eliminate the code in it
1007 ;;; from the IR1 representation. This involves unlinking it from its
1008 ;;; predecessors and successors and deleting various node-specific
1009 ;;; semantic information. BLOCK must be already removed from
1010 ;;; COMPONENT-DELETE-BLOCKS.
1011 (defun delete-block (block &optional silent)
1012 (declare (type cblock block))
1013 (aver (block-component block)) ; else block is already deleted!
1014 #!+high-security (aver (not (memq block (component-delete-blocks (block-component block)))))
1016 (note-block-deletion block))
1017 (setf (block-delete-p block) t)
1019 (dolist (b (block-pred block))
1020 (unlink-blocks b block)
1021 ;; In bug 147 the almost-all-blocks-have-a-successor invariant was
1022 ;; broken when successors were deleted without setting the
1023 ;; BLOCK-DELETE-P flags of their predececessors. Make sure that
1024 ;; doesn't happen again.
1025 (aver (not (and (null (block-succ b))
1026 (not (block-delete-p b))
1027 (not (eq b (component-head (block-component b))))))))
1028 (dolist (b (block-succ block))
1029 (unlink-blocks block b))
1031 (do-nodes-carefully (node block)
1032 (when (valued-node-p node)
1033 (delete-lvar-use node))
1035 (ref (delete-ref node))
1036 (cif (flush-dest (if-test node)))
1037 ;; The next two cases serve to maintain the invariant that a LET
1038 ;; always has a well-formed COMBINATION, REF and BIND. We delete
1039 ;; the lambda whenever we delete any of these, but we must be
1040 ;; careful that this LET has not already been partially deleted.
1042 (when (and (eq (basic-combination-kind node) :local)
1043 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
1044 (lvar-uses (basic-combination-fun node)))
1045 (let ((fun (combination-lambda node)))
1046 ;; If our REF was the second-to-last ref, and has been
1047 ;; deleted, then FUN may be a LET for some other
1049 (when (and (functional-letlike-p fun)
1050 (eq (let-combination fun) node))
1051 (delete-lambda fun))))
1052 (flush-dest (basic-combination-fun node))
1053 (dolist (arg (basic-combination-args node))
1054 (when arg (flush-dest arg))))
1056 (let ((lambda (bind-lambda node)))
1057 (unless (eq (functional-kind lambda) :deleted)
1058 (delete-lambda lambda))))
1060 (let ((value (exit-value node))
1061 (entry (exit-entry node)))
1065 (setf (entry-exits entry)
1066 (delq node (entry-exits entry))))))
1068 (dolist (exit (entry-exits node))
1069 (mark-for-deletion (node-block exit)))
1070 (let ((home (node-home-lambda node)))
1071 (setf (lambda-entries home) (delq node (lambda-entries home)))))
1073 (flush-dest (return-result node))
1074 (delete-return node))
1076 (flush-dest (set-value node))
1077 (let ((var (set-var node)))
1078 (setf (basic-var-sets var)
1079 (delete node (basic-var-sets var)))))
1081 (flush-dest (cast-value node)))))
1083 (remove-from-dfo block)
1086 ;;; Do stuff to indicate that the return node NODE is being deleted.
1087 (defun delete-return (node)
1088 (declare (type creturn node))
1089 (let* ((fun (return-lambda node))
1090 (tail-set (lambda-tail-set fun)))
1091 (aver (lambda-return fun))
1092 (setf (lambda-return fun) nil)
1093 (when (and tail-set (not (find-if #'lambda-return
1094 (tail-set-funs tail-set))))
1095 (setf (tail-set-type tail-set) *empty-type*)))
1098 ;;; If any of the VARS in FUN was never referenced and was not
1099 ;;; declared IGNORE, then complain.
1100 (defun note-unreferenced-vars (fun)
1101 (declare (type clambda fun))
1102 (dolist (var (lambda-vars fun))
1103 (unless (or (leaf-ever-used var)
1104 (lambda-var-ignorep var))
1105 (let ((*compiler-error-context* (lambda-bind fun)))
1106 (unless (policy *compiler-error-context* (= inhibit-warnings 3))
1107 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
1108 ;; requires this to be no more than a STYLE-WARNING.
1109 (compiler-style-warn "The variable ~S is defined but never used."
1110 (leaf-debug-name var)))
1111 (setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
1114 (defvar *deletion-ignored-objects* '(t nil))
1116 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
1117 ;;; our recursion so that we don't get lost in circular structures. We
1118 ;;; ignore the car of forms if they are a symbol (to prevent confusing
1119 ;;; function referencess with variables), and we also ignore anything
1121 (defun present-in-form (obj form depth)
1122 (declare (type (integer 0 20) depth))
1123 (cond ((= depth 20) nil)
1127 (let ((first (car form))
1129 (if (member first '(quote function))
1131 (or (and (not (symbolp first))
1132 (present-in-form obj first depth))
1133 (do ((l (cdr form) (cdr l))
1135 ((or (atom l) (> n 100))
1137 (declare (fixnum n))
1138 (when (present-in-form obj (car l) depth)
1141 ;;; This function is called on a block immediately before we delete
1142 ;;; it. We check to see whether any of the code about to die appeared
1143 ;;; in the original source, and emit a note if so.
1145 ;;; If the block was in a lambda is now deleted, then we ignore the
1146 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
1147 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
1148 ;;; reasonable for a function to not return, and there is a different
1149 ;;; note for that case anyway.
1151 ;;; If the actual source is an atom, then we use a bunch of heuristics
1152 ;;; to guess whether this reference really appeared in the original
1154 ;;; -- If a symbol, it must be interned and not a keyword.
1155 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
1156 ;;; or a character.)
1157 ;;; -- The atom must be "present" in the original source form, and
1158 ;;; present in all intervening actual source forms.
1159 (defun note-block-deletion (block)
1160 (let ((home (block-home-lambda block)))
1161 (unless (eq (functional-kind home) :deleted)
1162 (do-nodes (node nil block)
1163 (let* ((path (node-source-path node))
1164 (first (first path)))
1165 (when (or (eq first 'original-source-start)
1167 (or (not (symbolp first))
1168 (let ((pkg (symbol-package first)))
1170 (not (eq pkg (symbol-package :end))))))
1171 (not (member first *deletion-ignored-objects*))
1172 (not (typep first '(or fixnum character)))
1174 (present-in-form first x 0))
1175 (source-path-forms path))
1176 (present-in-form first (find-original-source path)
1178 (unless (return-p node)
1179 (let ((*compiler-error-context* node))
1180 (compiler-notify 'code-deletion-note
1181 :format-control "deleting unreachable code"
1182 :format-arguments nil)))
1186 ;;; Delete a node from a block, deleting the block if there are no
1187 ;;; nodes left. We remove the node from the uses of its LVAR.
1189 ;;; If the node is the last node, there must be exactly one successor.
1190 ;;; We link all of our precedessors to the successor and unlink the
1191 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1192 ;;; left, and the block is a successor of itself, then we replace the
1193 ;;; only node with a degenerate exit node. This provides a way to
1194 ;;; represent the bodyless infinite loop, given the prohibition on
1195 ;;; empty blocks in IR1.
1196 (defun unlink-node (node)
1197 (declare (type node node))
1198 (when (valued-node-p node)
1199 (delete-lvar-use node))
1201 (let* ((ctran (node-next node))
1202 (next (and ctran (ctran-next ctran)))
1203 (prev (node-prev node))
1204 (block (ctran-block prev))
1205 (prev-kind (ctran-kind prev))
1206 (last (block-last block)))
1208 (setf (block-type-asserted block) t)
1209 (setf (block-test-modified block) t)
1211 (cond ((or (eq prev-kind :inside-block)
1212 (and (eq prev-kind :block-start)
1213 (not (eq node last))))
1214 (cond ((eq node last)
1215 (setf (block-last block) (ctran-use prev))
1216 (setf (node-next (ctran-use prev)) nil))
1218 (setf (ctran-next prev) next)
1219 (setf (node-prev next) prev)
1220 (when (if-p next) ; AOP wanted
1221 (reoptimize-lvar (if-test next)))))
1222 (setf (node-prev node) nil)
1225 (aver (eq prev-kind :block-start))
1226 (aver (eq node last))
1227 (let* ((succ (block-succ block))
1228 (next (first succ)))
1229 (aver (singleton-p succ))
1231 ((eq block (first succ))
1232 (with-ir1-environment-from-node node
1233 (let ((exit (make-exit)))
1234 (setf (ctran-next prev) nil)
1235 (link-node-to-previous-ctran exit prev)
1236 (setf (block-last block) exit)))
1237 (setf (node-prev node) nil)
1240 (aver (eq (block-start-cleanup block)
1241 (block-end-cleanup block)))
1242 (unlink-blocks block next)
1243 (dolist (pred (block-pred block))
1244 (change-block-successor pred block next))
1245 (when (block-delete-p block)
1246 (let ((component (block-component block)))
1247 (setf (component-delete-blocks component)
1248 (delq block (component-delete-blocks component)))))
1249 (remove-from-dfo block)
1250 (setf (block-delete-p block) t)
1251 (setf (node-prev node) nil)
1254 ;;; Return true if NODE has been deleted, false if it is still a valid
1256 (defun node-deleted (node)
1257 (declare (type node node))
1258 (let ((prev (node-prev node)))
1260 (let ((block (ctran-block prev)))
1261 (and (block-component block)
1262 (not (block-delete-p block))))))))
1264 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1265 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1266 ;;; triggered by deletion.
1267 (defun delete-component (component)
1268 (declare (type component component))
1269 (aver (null (component-new-functionals component)))
1270 (setf (component-kind component) :deleted)
1271 (do-blocks (block component)
1272 (delete-block-lazily block))
1273 (dolist (fun (component-lambdas component))
1274 (unless (eq (functional-kind fun) :deleted)
1275 (setf (functional-kind fun) nil)
1276 (setf (functional-entry-fun fun) nil)
1277 (setf (leaf-refs fun) nil)
1278 (delete-functional fun)))
1279 (clean-component component)
1282 ;;; Remove all pending blocks to be deleted. Return the nearest live
1283 ;;; block after or equal to BLOCK.
1284 (defun clean-component (component &optional block)
1285 (loop while (component-delete-blocks component)
1286 ;; actual deletion of a block may queue new blocks
1287 do (let ((current (pop (component-delete-blocks component))))
1288 (when (eq block current)
1289 (setq block (block-next block)))
1290 (delete-block current)))
1293 ;;; Convert code of the form
1294 ;;; (FOO ... (FUN ...) ...)
1296 ;;; (FOO ... ... ...).
1297 ;;; In other words, replace the function combination FUN by its
1298 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1299 ;;; to blow out of whatever transform called this. Note, as the number
1300 ;;; of arguments changes, the transform must be prepared to return a
1301 ;;; lambda with a new lambda-list with the correct number of
1303 (defun extract-fun-args (lvar fun num-args)
1305 "If LVAR is a call to FUN with NUM-ARGS args, change those arguments
1306 to feed directly to the LVAR-DEST of LVAR, which must be a
1308 (declare (type lvar lvar)
1310 (type index num-args))
1311 (let ((outside (lvar-dest lvar))
1312 (inside (lvar-uses lvar)))
1313 (aver (combination-p outside))
1314 (unless (combination-p inside)
1315 (give-up-ir1-transform))
1316 (let ((inside-fun (combination-fun inside)))
1317 (unless (eq (lvar-fun-name inside-fun) fun)
1318 (give-up-ir1-transform))
1319 (let ((inside-args (combination-args inside)))
1320 (unless (= (length inside-args) num-args)
1321 (give-up-ir1-transform))
1322 (let* ((outside-args (combination-args outside))
1323 (arg-position (position lvar outside-args))
1324 (before-args (subseq outside-args 0 arg-position))
1325 (after-args (subseq outside-args (1+ arg-position))))
1326 (dolist (arg inside-args)
1327 (setf (lvar-dest arg) outside)
1328 (flush-lvar-externally-checkable-type arg))
1329 (setf (combination-args inside) nil)
1330 (setf (combination-args outside)
1331 (append before-args inside-args after-args))
1332 (change-ref-leaf (lvar-uses inside-fun)
1333 (find-free-fun 'list "???"))
1334 (setf (combination-kind inside)
1335 (info :function :info 'list))
1336 (setf (node-derived-type inside) *wild-type*)
1340 (defun flush-combination (combination)
1341 (declare (type combination combination))
1342 (flush-dest (combination-fun combination))
1343 (dolist (arg (combination-args combination))
1345 (unlink-node combination)
1351 ;;; Change the LEAF that a REF refers to.
1352 (defun change-ref-leaf (ref leaf)
1353 (declare (type ref ref) (type leaf leaf))
1354 (unless (eq (ref-leaf ref) leaf)
1355 (push ref (leaf-refs leaf))
1357 (setf (ref-leaf ref) leaf)
1358 (setf (leaf-ever-used leaf) t)
1359 (let* ((ltype (leaf-type leaf))
1360 (vltype (make-single-value-type ltype)))
1361 (if (let* ((lvar (node-lvar ref))
1362 (dest (and lvar (lvar-dest lvar))))
1363 (and (basic-combination-p dest)
1364 (eq lvar (basic-combination-fun dest))
1365 (csubtypep ltype (specifier-type 'function))))
1366 (setf (node-derived-type ref) vltype)
1367 (derive-node-type ref vltype)))
1368 (reoptimize-lvar (node-lvar ref)))
1371 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1372 (defun substitute-leaf (new-leaf old-leaf)
1373 (declare (type leaf new-leaf old-leaf))
1374 (dolist (ref (leaf-refs old-leaf))
1375 (change-ref-leaf ref new-leaf))
1378 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1379 ;;; whether to substitute
1380 (defun substitute-leaf-if (test new-leaf old-leaf)
1381 (declare (type leaf new-leaf old-leaf) (type function test))
1382 (dolist (ref (leaf-refs old-leaf))
1383 (when (funcall test ref)
1384 (change-ref-leaf ref new-leaf)))
1387 ;;; Return a LEAF which represents the specified constant object. If
1388 ;;; the object is not in *CONSTANTS*, then we create a new constant
1389 ;;; LEAF and enter it.
1390 (defun find-constant (object)
1392 ;; FIXME: What is the significance of this test? ("things
1393 ;; that are worth uniquifying"?)
1394 '(or symbol number character instance))
1395 (or (gethash object *constants*)
1396 (setf (gethash object *constants*)
1397 (make-constant :value object
1398 :%source-name '.anonymous.
1399 :type (ctype-of object)
1400 :where-from :defined)))
1401 (make-constant :value object
1402 :%source-name '.anonymous.
1403 :type (ctype-of object)
1404 :where-from :defined)))
1406 ;;; Return true if VAR would have to be closed over if environment
1407 ;;; analysis ran now (i.e. if there are any uses that have a different
1408 ;;; home lambda than VAR's home.)
1409 (defun closure-var-p (var)
1410 (declare (type lambda-var var))
1411 (let ((home (lambda-var-home var)))
1412 (cond ((eq (functional-kind home) :deleted)
1414 (t (let ((home (lambda-home home)))
1417 :key #'node-home-lambda
1419 (or (frob (leaf-refs var))
1420 (frob (basic-var-sets var)))))))))
1422 ;;; If there is a non-local exit noted in ENTRY's environment that
1423 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1424 (defun find-nlx-info (exit)
1425 (declare (type exit exit))
1426 (let* ((entry (exit-entry exit))
1427 (entry-cleanup (entry-cleanup entry)))
1428 (dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
1429 (when (eq (nlx-info-exit nlx) exit)
1432 ;;;; functional hackery
1434 (declaim (ftype (sfunction (functional) clambda) main-entry))
1435 (defun main-entry (functional)
1436 (etypecase functional
1437 (clambda functional)
1439 (optional-dispatch-main-entry functional))))
1441 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1442 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1443 ;;; optional with null default and no SUPPLIED-P. There must be a
1444 ;;; &REST arg with no references.
1445 (declaim (ftype (sfunction (functional) boolean) looks-like-an-mv-bind))
1446 (defun looks-like-an-mv-bind (functional)
1447 (and (optional-dispatch-p functional)
1448 (do ((arg (optional-dispatch-arglist functional) (cdr arg)))
1450 (let ((info (lambda-var-arg-info (car arg))))
1451 (unless info (return nil))
1452 (case (arg-info-kind info)
1454 (when (or (arg-info-supplied-p info) (arg-info-default info))
1457 (return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
1461 ;;; Return true if function is an external entry point. This is true
1462 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1463 ;;; (:TOPLEVEL kind.)
1465 (declare (type functional fun))
1466 (not (null (member (functional-kind fun) '(:external :toplevel)))))
1468 ;;; If LVAR's only use is a non-notinline global function reference,
1469 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1470 ;;; is true, then we don't care if the leaf is NOTINLINE.
1471 (defun lvar-fun-name (lvar &optional notinline-ok)
1472 (declare (type lvar lvar))
1473 (let ((use (lvar-uses lvar)))
1475 (let ((leaf (ref-leaf use)))
1476 (if (and (global-var-p leaf)
1477 (eq (global-var-kind leaf) :global-function)
1478 (or (not (defined-fun-p leaf))
1479 (not (eq (defined-fun-inlinep leaf) :notinline))
1481 (leaf-source-name leaf)
1485 ;;; Return the source name of a combination. (This is an idiom
1486 ;;; which was used in CMU CL. I gather it always works. -- WHN)
1487 (defun combination-fun-source-name (combination)
1488 (let ((ref (lvar-uses (combination-fun combination))))
1489 (leaf-source-name (ref-leaf ref))))
1491 ;;; Return the COMBINATION node that is the call to the LET FUN.
1492 (defun let-combination (fun)
1493 (declare (type clambda fun))
1494 (aver (functional-letlike-p fun))
1495 (lvar-dest (node-lvar (first (leaf-refs fun)))))
1497 ;;; Return the initial value lvar for a LET variable, or NIL if there
1499 (defun let-var-initial-value (var)
1500 (declare (type lambda-var var))
1501 (let ((fun (lambda-var-home var)))
1502 (elt (combination-args (let-combination fun))
1503 (position-or-lose var (lambda-vars fun)))))
1505 ;;; Return the LAMBDA that is called by the local CALL.
1506 (defun combination-lambda (call)
1507 (declare (type basic-combination call))
1508 (aver (eq (basic-combination-kind call) :local))
1509 (ref-leaf (lvar-uses (basic-combination-fun call))))
1511 (defvar *inline-expansion-limit* 200
1513 "an upper limit on the number of inline function calls that will be expanded
1514 in any given code object (single function or block compilation)")
1516 ;;; Check whether NODE's component has exceeded its inline expansion
1517 ;;; limit, and warn if so, returning NIL.
1518 (defun inline-expansion-ok (node)
1519 (let ((expanded (incf (component-inline-expansions
1521 (node-block node))))))
1522 (cond ((> expanded *inline-expansion-limit*) nil)
1523 ((= expanded *inline-expansion-limit*)
1524 ;; FIXME: If the objective is to stop the recursive
1525 ;; expansion of inline functions, wouldn't it be more
1526 ;; correct to look back through surrounding expansions
1527 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1528 ;; possibly stored elsewhere too) and suppress expansion
1529 ;; and print this warning when the function being proposed
1530 ;; for inline expansion is found there? (I don't like the
1531 ;; arbitrary numerical limit in principle, and I think
1532 ;; it'll be a nuisance in practice if we ever want the
1533 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1534 ;; arbitrarily huge blocks of code. -- WHN)
1535 (let ((*compiler-error-context* node))
1536 (compiler-notify "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1537 probably trying to~% ~
1538 inline a recursive function."
1539 *inline-expansion-limit*))
1543 ;;; Make sure that FUNCTIONAL is not let-converted or deleted.
1544 (defun assure-functional-live-p (functional)
1545 (declare (type functional functional))
1547 ;; looks LET-converted
1548 (functional-somewhat-letlike-p functional)
1549 ;; It's possible for a LET-converted function to end up
1550 ;; deleted later. In that case, for the purposes of this
1551 ;; analysis, it is LET-converted: LET-converted functionals
1552 ;; are too badly trashed to expand them inline, and deleted
1553 ;; LET-converted functionals are even worse.
1554 (memq (functional-kind functional) '(:deleted :zombie))))
1555 (throw 'locall-already-let-converted functional)))
1557 (defun call-full-like-p (call)
1558 (declare (type combination call))
1559 (let ((kind (basic-combination-kind call)))
1561 (and (fun-info-p kind)
1562 (not (fun-info-ir2-convert kind))
1563 (dolist (template (fun-info-templates kind) t)
1564 (when (eq (template-ltn-policy template) :fast-safe)
1565 (multiple-value-bind (val win)
1566 (valid-fun-use call (template-type template))
1567 (when (or val (not win)) (return nil)))))))))
1571 ;;; Apply a function to some arguments, returning a list of the values
1572 ;;; resulting of the evaluation. If an error is signalled during the
1573 ;;; application, then we produce a warning message using WARN-FUN and
1574 ;;; return NIL as our second value to indicate this. NODE is used as
1575 ;;; the error context for any error message, and CONTEXT is a string
1576 ;;; that is spliced into the warning.
1577 (declaim (ftype (sfunction ((or symbol function) list node function string)
1578 (values list boolean))
1580 (defun careful-call (function args node warn-fun context)
1582 (multiple-value-list
1583 (handler-case (apply function args)
1585 (let ((*compiler-error-context* node))
1586 (funcall warn-fun "Lisp error during ~A:~%~A" context condition)
1587 (return-from careful-call (values nil nil))))))
1590 ;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
1593 ((deffrob (basic careful compiler transform)
1595 (defun ,careful (specifier)
1596 (handler-case (,basic specifier)
1597 (sb!kernel::arg-count-error (condition)
1598 (values nil (list (format nil "~A" condition))))
1599 (simple-error (condition)
1600 (values nil (list* (simple-condition-format-control condition)
1601 (simple-condition-format-arguments condition))))))
1602 (defun ,compiler (specifier)
1603 (multiple-value-bind (type error-args) (,careful specifier)
1605 (apply #'compiler-error error-args))))
1606 (defun ,transform (specifier)
1607 (multiple-value-bind (type error-args) (,careful specifier)
1609 (apply #'give-up-ir1-transform
1611 (deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type)
1612 (deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type))
1615 ;;;; utilities used at run-time for parsing &KEY args in IR1
1617 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1618 ;;; the lvar for the value of the &KEY argument KEY in the list of
1619 ;;; lvars ARGS. It returns the lvar if the keyword is present, or NIL
1620 ;;; otherwise. The legality and constantness of the keywords should
1621 ;;; already have been checked.
1622 (declaim (ftype (sfunction (list keyword) (or lvar null))
1624 (defun find-keyword-lvar (args key)
1625 (do ((arg args (cddr arg)))
1627 (when (eq (lvar-value (first arg)) key)
1628 (return (second arg)))))
1630 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1631 ;;; verify that alternating lvars in ARGS are constant and that there
1632 ;;; is an even number of args.
1633 (declaim (ftype (sfunction (list) boolean) check-key-args-constant))
1634 (defun check-key-args-constant (args)
1635 (do ((arg args (cddr arg)))
1637 (unless (and (rest arg)
1638 (constant-lvar-p (first arg)))
1641 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1642 ;;; verify that the list of lvars ARGS is a well-formed &KEY arglist
1643 ;;; and that only keywords present in the list KEYS are supplied.
1644 (declaim (ftype (sfunction (list list) boolean) check-transform-keys))
1645 (defun check-transform-keys (args keys)
1646 (and (check-key-args-constant args)
1647 (do ((arg args (cddr arg)))
1649 (unless (member (lvar-value (first arg)) keys)
1654 ;;; Called by the expansion of the EVENT macro.
1655 (declaim (ftype (sfunction (event-info (or node null)) *) %event))
1656 (defun %event (info node)
1657 (incf (event-info-count info))
1658 (when (and (>= (event-info-level info) *event-note-threshold*)
1659 (policy (or node *lexenv*)
1660 (= inhibit-warnings 0)))
1661 (let ((*compiler-error-context* node))
1662 (compiler-notify (event-info-description info))))
1664 (let ((action (event-info-action info)))
1665 (when action (funcall action node))))
1668 (defun make-cast (value type policy)
1669 (declare (type lvar value)
1671 (type policy policy))
1672 (%make-cast :asserted-type type
1673 :type-to-check (maybe-weaken-check type policy)
1675 :derived-type (coerce-to-values type)))
1677 (defun cast-type-check (cast)
1678 (declare (type cast cast))
1679 (when (cast-reoptimize cast)
1680 (ir1-optimize-cast cast t))
1681 (cast-%type-check cast))
1683 (defun note-single-valuified-lvar (lvar)
1684 (declare (type (or lvar null) lvar))
1686 (let ((use (lvar-uses lvar)))
1688 (let ((leaf (ref-leaf use)))
1689 (when (and (lambda-var-p leaf)
1690 (null (rest (leaf-refs leaf))))
1691 (reoptimize-lambda-var leaf))))
1692 ((or (listp use) (combination-p use))
1693 (do-uses (node lvar)
1694 (setf (node-reoptimize node) t)
1695 (setf (block-reoptimize (node-block node)) t)
1696 (setf (component-reoptimize (node-component node)) t)))))))