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)
55 ;;;; continuation use hacking
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 continuation use information so that NODE is no longer a
72 ;;; use of its CONT. If the old continuation doesn't start its block,
73 ;;; then we don't update the BLOCK-START-USES, since it will be
74 ;;; deleted when we are done.
76 ;;; Note: if you call this function, you may have to do a
77 ;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something
79 (declaim (ftype (sfunction (node) (values))
82 ;;; Just delete NODE from its LVAR uses; LVAR is preserved so it may
83 ;;; be given a new use.
84 (defun %delete-lvar-use (node)
85 (let* ((lvar (node-lvar node)))
87 (if (listp (lvar-uses lvar))
88 (let ((new-uses (delq node (lvar-uses lvar))))
89 (setf (lvar-uses lvar)
90 (if (singleton-p new-uses)
93 (setf (lvar-uses lvar) nil))
94 (setf (node-lvar node) nil)))
96 ;;; Delete NODE from its LVAR uses.
97 (defun delete-lvar-use (node)
98 (let ((lvar (node-lvar node)))
100 (%delete-lvar-use node)
101 (if (null (lvar-uses lvar))
102 (binding* ((dest (lvar-dest lvar) :exit-if-null)
103 (() (not (node-deleted dest)) :exit-if-null)
104 (block (node-block dest)))
105 (mark-for-deletion block))
106 (reoptimize-lvar lvar))))
109 ;;; Update continuation use information so that NODE uses CONT. If
110 ;;; CONT is :UNUSED, then we set its block to NODE's NODE-BLOCK (which
113 ;;; Note: if you call this function, you may have to do a
114 ;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something
116 (declaim (ftype (sfunction (node (or lvar null)) (values)) add-lvar-use))
117 (defun add-lvar-use (node lvar)
118 (aver (not (node-lvar node)))
120 (let ((uses (lvar-uses lvar)))
121 (setf (lvar-uses lvar)
128 (setf (node-lvar node) lvar)))
132 ;;; Return true if LVAR destination is executed immediately after
133 ;;; NODE. Cleanups are ignored.
134 (defun immediately-used-p (lvar node)
135 (declare (type lvar lvar) (type node node))
136 (aver (eq (node-lvar node) lvar))
137 (and (eq (lvar-dest lvar)
138 (acond ((node-next node)
140 (t (let* ((block (node-block node))
141 (next-block (first (block-succ block))))
142 (block-start-node next-block)))))))
144 ;;;; continuation substitution
146 ;;; In OLD's DEST, replace OLD with NEW. NEW's DEST must initially be
147 ;;; NIL. We do not flush OLD's DEST.
148 (defun substitute-lvar (new old)
149 (declare (type lvar old new))
150 (aver (not (lvar-dest new)))
151 (let ((dest (lvar-dest old)))
154 (cif (setf (if-test dest) new))
155 (cset (setf (set-value dest) new))
156 (creturn (setf (return-result dest) new))
157 (exit (setf (exit-value dest) new))
159 (if (eq old (basic-combination-fun dest))
160 (setf (basic-combination-fun dest) new)
161 (setf (basic-combination-args dest)
162 (nsubst new old (basic-combination-args dest)))))
163 (cast (setf (cast-value dest) new)))
165 (setf (lvar-dest old) nil)
166 (setf (lvar-dest new) dest)
167 (flush-lvar-externally-checkable-type new))
170 ;;; Replace all uses of OLD with uses of NEW, where NEW has an
171 ;;; arbitary number of uses.
172 (defun substitute-lvar-uses (new old)
173 (declare (type lvar old)
174 (type (or lvar null) new))
177 (%delete-lvar-use node)
179 (add-lvar-use node new)))
181 (when new (reoptimize-lvar new))
184 ;;;; block starting/creation
186 ;;; Return the block that CTRAN is the start of, making a block if
187 ;;; necessary. This function is called by IR1 translators which may
188 ;;; cause a CTRAN to be used more than once. Every CTRAN which may be
189 ;;; used more than once must start a block by the time that anyone
190 ;;; does a USE-CTRAN on it.
192 ;;; We also throw the block into the next/prev list for the
193 ;;; *CURRENT-COMPONENT* so that we keep track of which blocks we have
195 (defun ctran-starts-block (ctran)
196 (declare (type ctran ctran))
197 (ecase (ctran-kind ctran)
199 (aver (not (ctran-block ctran)))
200 (let* ((next (component-last-block *current-component*))
201 (prev (block-prev next))
202 (new-block (make-block ctran)))
203 (setf (block-next new-block) next
204 (block-prev new-block) prev
205 (block-prev next) new-block
206 (block-next prev) new-block
207 (ctran-block ctran) new-block
208 (ctran-kind ctran) :block-start)
209 (aver (not (ctran-use ctran)))
212 (ctran-block ctran))))
214 ;;; Ensure that CTRAN is the start of a block so that the use set can
215 ;;; be freely manipulated.
216 (defun ensure-block-start (ctran)
217 (declare (type ctran ctran))
218 (let ((kind (ctran-kind ctran)))
222 (setf (ctran-block ctran)
223 (make-block-key :start ctran))
224 (setf (ctran-kind ctran) :block-start))
226 (node-ends-block (ctran-use ctran)))))
231 ;;; Filter values of LVAR through FORM, which must be an ordinary/mv
232 ;;; call. First argument must be 'DUMMY, which will be replaced with
233 ;;; LVAR. In case of an ordinary call the function should not have
234 ;;; return type NIL. We create a new "filtered" lvar.
236 ;;; TODO: remove preconditions.
237 (defun filter-lvar (lvar form)
238 (declare (type lvar lvar) (type list form))
239 (let* ((dest (lvar-dest lvar))
240 (ctran (node-prev dest)))
241 (with-ir1-environment-from-node dest
243 (ensure-block-start ctran)
244 (let* ((old-block (ctran-block ctran))
245 (new-start (make-ctran))
246 (filtered-lvar (make-lvar))
247 (new-block (ctran-starts-block new-start)))
249 ;; Splice in the new block before DEST, giving the new block
250 ;; all of DEST's predecessors.
251 (dolist (block (block-pred old-block))
252 (change-block-successor block old-block new-block))
254 (ir1-convert new-start ctran filtered-lvar form)
256 ;; KLUDGE: Comments at the head of this function in CMU CL
257 ;; said that somewhere in here we
258 ;; Set the new block's start and end cleanups to the *start*
259 ;; cleanup of PREV's block. This overrides the incorrect
260 ;; default from WITH-IR1-ENVIRONMENT-FROM-NODE.
261 ;; Unfortunately I can't find any code which corresponds to this.
262 ;; Perhaps it was a stale comment? Or perhaps I just don't
263 ;; understand.. -- WHN 19990521
265 ;; Replace 'DUMMY with the LVAR. (We can find 'DUMMY because
266 ;; no LET conversion has been done yet.) The [mv-]combination
267 ;; code from the call in the form will be the use of the new
268 ;; check lvar. We substitute for the first argument of
270 (let* ((node (lvar-use filtered-lvar))
271 (args (basic-combination-args node))
272 (victim (first args)))
273 (aver (eq (constant-value (ref-leaf (lvar-use victim)))
276 (substitute-lvar filtered-lvar lvar)
277 (substitute-lvar lvar victim)
280 ;; Invoking local call analysis converts this call to a LET.
281 (locall-analyze-component *current-component*))))
284 ;;; Delete NODE and VALUE. It may result in some calls becoming tail.
285 (defun delete-filter (node lvar value)
286 (aver (eq (lvar-dest value) node))
287 (aver (eq (node-lvar node) lvar))
288 (cond (lvar (collect ((merges))
289 (when (return-p (lvar-dest lvar))
291 (when (and (basic-combination-p use)
292 (eq (basic-combination-kind use) :local))
294 (%delete-lvar-use node)
295 (substitute-lvar-uses lvar value)
298 (dolist (merge (merges))
299 (merge-tail-sets merge)))))
300 (t (flush-dest value)
301 (unlink-node node))))
303 ;;;; miscellaneous shorthand functions
305 ;;; Return the home (i.e. enclosing non-LET) CLAMBDA for NODE. Since
306 ;;; the LEXENV-LAMBDA may be deleted, we must chain up the
307 ;;; LAMBDA-CALL-LEXENV thread until we find a CLAMBDA that isn't
308 ;;; deleted, and then return its home.
309 (defun node-home-lambda (node)
310 (declare (type node node))
311 (do ((fun (lexenv-lambda (node-lexenv node))
312 (lexenv-lambda (lambda-call-lexenv fun))))
313 ((not (eq (functional-kind fun) :deleted))
315 (when (eq (lambda-home fun) fun)
318 #!-sb-fluid (declaim (inline node-block))
319 (defun node-block (node)
320 (ctran-block (node-prev node)))
321 (declaim (ftype (sfunction (node) component) node-component))
322 (defun node-component (node)
323 (block-component (node-block node)))
324 (declaim (ftype (sfunction (node) physenv) node-physenv))
325 (defun node-physenv (node)
326 (lambda-physenv (node-home-lambda node)))
327 #!-sb-fluid (declaim (inline node-dest))
328 (defun node-dest (node)
329 (awhen (node-lvar node) (lvar-dest it)))
331 (declaim (ftype (sfunction (clambda) cblock) lambda-block))
332 (defun lambda-block (clambda)
333 (node-block (lambda-bind clambda)))
334 (declaim (ftype (sfunction (clambda) component) lambda-component))
335 (defun lambda-component (clambda)
336 (block-component (lambda-block clambda)))
338 (declaim (ftype (sfunction (cblock) node) block-start-node))
339 (defun block-start-node (block)
340 (ctran-next (block-start block)))
342 ;;; Return the enclosing cleanup for environment of the first or last
344 (defun block-start-cleanup (block)
345 (node-enclosing-cleanup (block-start-node block)))
346 (defun block-end-cleanup (block)
347 (node-enclosing-cleanup (block-last block)))
349 ;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
350 ;;; if there is none.
352 ;;; There can legitimately be no home lambda in dead code early in the
353 ;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
354 ;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
355 ;;; where the block is just a placeholder during parsing and doesn't
356 ;;; actually correspond to code which will be written anywhere.
357 (declaim (ftype (sfunction (cblock) (or clambda null)) block-home-lambda-or-null))
358 (defun block-home-lambda-or-null (block)
359 (if (node-p (block-last block))
360 ;; This is the old CMU CL way of doing it.
361 (node-home-lambda (block-last block))
362 ;; Now that SBCL uses this operation more aggressively than CMU
363 ;; CL did, the old CMU CL way of doing it can fail in two ways.
364 ;; 1. It can fail in a few cases even when a meaningful home
365 ;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
367 ;; 2. It can fail when converting a form which is born orphaned
368 ;; so that it never had a meaningful home lambda, e.g. a form
369 ;; which follows a RETURN-FROM or GO form.
370 (let ((pred-list (block-pred block)))
371 ;; To deal with case 1, we reason that
372 ;; previous-in-target-execution-order blocks should be in the
373 ;; same lambda, and that they seem in practice to be
374 ;; previous-in-compilation-order blocks too, so we look back
375 ;; to find one which is sufficiently initialized to tell us
376 ;; what the home lambda is.
378 ;; We could get fancy about this, flooding through the
379 ;; graph of all the previous blocks, but in practice it
380 ;; seems to work just to grab the first previous block and
382 (node-home-lambda (block-last (first pred-list)))
383 ;; In case 2, we end up with an empty PRED-LIST and
384 ;; have to punt: There's no home lambda.
387 ;;; Return the non-LET LAMBDA that holds BLOCK's code.
388 (declaim (ftype (sfunction (cblock) clambda) block-home-lambda))
389 (defun block-home-lambda (block)
390 (block-home-lambda-or-null block))
392 ;;; Return the IR1 physical environment for BLOCK.
393 (declaim (ftype (sfunction (cblock) physenv) block-physenv))
394 (defun block-physenv (block)
395 (lambda-physenv (block-home-lambda block)))
397 ;;; Return the Top Level Form number of PATH, i.e. the ordinal number
398 ;;; of its original source's top level form in its compilation unit.
399 (defun source-path-tlf-number (path)
400 (declare (list path))
403 ;;; Return the (reversed) list for the PATH in the original source
404 ;;; (with the Top Level Form number last).
405 (defun source-path-original-source (path)
406 (declare (list path) (inline member))
407 (cddr (member 'original-source-start path :test #'eq)))
409 ;;; Return the Form Number of PATH's original source inside the Top
410 ;;; Level Form that contains it. This is determined by the order that
411 ;;; we walk the subforms of the top level source form.
412 (defun source-path-form-number (path)
413 (declare (list path) (inline member))
414 (cadr (member 'original-source-start path :test #'eq)))
416 ;;; Return a list of all the enclosing forms not in the original
417 ;;; source that converted to get to this form, with the immediate
418 ;;; source for node at the start of the list.
419 (defun source-path-forms (path)
420 (subseq path 0 (position 'original-source-start path)))
422 ;;; Return the innermost source form for NODE.
423 (defun node-source-form (node)
424 (declare (type node node))
425 (let* ((path (node-source-path node))
426 (forms (source-path-forms path)))
429 (values (find-original-source path)))))
431 ;;; Return NODE-SOURCE-FORM, T if continuation has a single use,
432 ;;; otherwise NIL, NIL.
433 (defun lvar-source (lvar)
434 (let ((use (lvar-uses lvar)))
437 (values (node-source-form use) t))))
439 ;;; Return the unique node, delivering a value to LVAR.
440 #!-sb-fluid (declaim (inline lvar-use))
441 (defun lvar-use (lvar)
442 (the (not list) (lvar-uses lvar)))
444 #!-sb-fluid (declaim (inline lvar-has-single-use-p))
445 (defun lvar-has-single-use-p (lvar)
446 (typep (lvar-uses lvar) '(not list)))
448 ;;; Return the LAMBDA that is CTRAN's home, or NIL if there is none.
449 (declaim (ftype (sfunction (ctran) (or clambda null))
450 ctran-home-lambda-or-null))
451 (defun ctran-home-lambda-or-null (ctran)
452 ;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
453 ;; implementation might not be quite right, or might be uglier than
454 ;; necessary. It appears that the original Python never found a need
455 ;; to do this operation. The obvious things based on
456 ;; NODE-HOME-LAMBDA of CTRAN-USE usually work; then if that fails,
457 ;; BLOCK-HOME-LAMBDA of CTRAN-BLOCK works, given that we
458 ;; generalize it enough to grovel harder when the simple CMU CL
459 ;; approach fails, and furthermore realize that in some exceptional
460 ;; cases it might return NIL. -- WHN 2001-12-04
461 (cond ((ctran-use ctran)
462 (node-home-lambda (ctran-use ctran)))
464 (block-home-lambda-or-null (ctran-block ctran)))
466 (bug "confused about home lambda for ~S" ctran))))
468 ;;; Return the LAMBDA that is CTRAN's home.
469 (declaim (ftype (sfunction (ctran) clambda) ctran-home-lambda))
470 (defun ctran-home-lambda (ctran)
471 (ctran-home-lambda-or-null ctran))
473 #!-sb-fluid (declaim (inline lvar-single-value-p))
474 (defun lvar-single-value-p (lvar)
476 (let ((dest (lvar-dest lvar)))
481 (eq (basic-combination-fun dest) lvar))
484 (declare (notinline lvar-single-value-p))
485 (and (not (values-type-p (cast-asserted-type dest)))
486 (lvar-single-value-p (node-lvar dest)))))
490 (defun principal-lvar-end (lvar)
491 (loop for prev = lvar then (node-lvar dest)
492 for dest = (and prev (lvar-dest prev))
494 finally (return (values dest prev))))
496 (defun principal-lvar-single-valuify (lvar)
497 (loop for prev = lvar then (node-lvar dest)
498 for dest = (and prev (lvar-dest prev))
500 do (setf (node-derived-type dest)
501 (make-short-values-type (list (single-value-type
502 (node-derived-type dest)))))
503 (reoptimize-lvar prev)))
505 ;;; Return a new LEXENV just like DEFAULT except for the specified
506 ;;; slot values. Values for the alist slots are NCONCed to the
507 ;;; beginning of the current value, rather than replacing it entirely.
508 (defun make-lexenv (&key (default *lexenv*)
509 funs vars blocks tags
511 (lambda (lexenv-lambda default))
512 (cleanup (lexenv-cleanup default))
513 (policy (lexenv-policy default)))
514 (macrolet ((frob (var slot)
515 `(let ((old (,slot default)))
519 (internal-make-lexenv
520 (frob funs lexenv-funs)
521 (frob vars lexenv-vars)
522 (frob blocks lexenv-blocks)
523 (frob tags lexenv-tags)
524 (frob type-restrictions lexenv-type-restrictions)
525 lambda cleanup policy)))
527 ;;; Makes a LEXENV, suitable for using in a MACROLET introduced
529 (defun make-restricted-lexenv (lexenv)
530 (flet ((fun-good-p (fun)
531 (destructuring-bind (name . thing) fun
532 (declare (ignore name))
536 (cons (aver (eq (car thing) 'macro))
539 (destructuring-bind (name . thing) var
540 (declare (ignore name))
543 (cons (aver (eq (car thing) 'macro))
545 (heap-alien-info nil)))))
546 (internal-make-lexenv
547 (remove-if-not #'fun-good-p (lexenv-funs lexenv))
548 (remove-if-not #'var-good-p (lexenv-vars lexenv))
551 (lexenv-type-restrictions lexenv) ; XXX
554 (lexenv-policy lexenv))))
556 ;;;; flow/DFO/component hackery
558 ;;; Join BLOCK1 and BLOCK2.
559 (defun link-blocks (block1 block2)
560 (declare (type cblock block1 block2))
561 (setf (block-succ block1)
562 (if (block-succ block1)
563 (%link-blocks block1 block2)
565 (push block1 (block-pred block2))
567 (defun %link-blocks (block1 block2)
568 (declare (type cblock block1 block2))
569 (let ((succ1 (block-succ block1)))
570 (aver (not (memq block2 succ1)))
571 (cons block2 succ1)))
573 ;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
574 ;;; this leaves a successor with a single predecessor that ends in an
575 ;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
576 ;;; now be able to be propagated to the successor.
577 (defun unlink-blocks (block1 block2)
578 (declare (type cblock block1 block2))
579 (let ((succ1 (block-succ block1)))
580 (if (eq block2 (car succ1))
581 (setf (block-succ block1) (cdr succ1))
582 (do ((succ (cdr succ1) (cdr succ))
584 ((eq (car succ) block2)
585 (setf (cdr prev) (cdr succ)))
588 (let ((new-pred (delq block1 (block-pred block2))))
589 (setf (block-pred block2) new-pred)
590 (when (singleton-p new-pred)
591 (let ((pred-block (first new-pred)))
592 (when (if-p (block-last pred-block))
593 (setf (block-test-modified pred-block) t)))))
596 ;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
597 ;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
598 ;;; consequent/alternative blocks to point to NEW. We also set
599 ;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
600 ;;; the new successor.
601 (defun change-block-successor (block old new)
602 (declare (type cblock new old block))
603 (unlink-blocks block old)
604 (let ((last (block-last block))
605 (comp (block-component block)))
606 (setf (component-reanalyze comp) t)
609 (setf (block-test-modified block) t)
610 (let* ((succ-left (block-succ block))
611 (new (if (and (eq new (component-tail comp))
615 (unless (memq new succ-left)
616 (link-blocks block new))
617 (macrolet ((frob (slot)
618 `(when (eq (,slot last) old)
619 (setf (,slot last) new))))
621 (frob if-alternative)
622 (when (eq (if-consequent last)
623 (if-alternative last))
624 (setf (component-reoptimize (block-component block)) t)))))
626 (unless (memq new (block-succ block))
627 (link-blocks block new)))))
631 ;;; Unlink a block from the next/prev chain. We also null out the
633 (declaim (ftype (sfunction (cblock) (values)) remove-from-dfo))
634 (defun remove-from-dfo (block)
635 (let ((next (block-next block))
636 (prev (block-prev block)))
637 (setf (block-component block) nil)
638 (setf (block-next prev) next)
639 (setf (block-prev next) prev))
642 ;;; Add BLOCK to the next/prev chain following AFTER. We also set the
643 ;;; COMPONENT to be the same as for AFTER.
644 (defun add-to-dfo (block after)
645 (declare (type cblock block after))
646 (let ((next (block-next after))
647 (comp (block-component after)))
648 (aver (not (eq (component-kind comp) :deleted)))
649 (setf (block-component block) comp)
650 (setf (block-next after) block)
651 (setf (block-prev block) after)
652 (setf (block-next block) next)
653 (setf (block-prev next) block))
656 ;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
657 ;;; the head and tail which are set to T.
658 (declaim (ftype (sfunction (component) (values)) clear-flags))
659 (defun clear-flags (component)
660 (let ((head (component-head component))
661 (tail (component-tail component)))
662 (setf (block-flag head) t)
663 (setf (block-flag tail) t)
664 (do-blocks (block component)
665 (setf (block-flag block) nil)))
668 ;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
669 ;;; true in the head and tail blocks.
670 (declaim (ftype (sfunction () component) make-empty-component))
671 (defun make-empty-component ()
672 (let* ((head (make-block-key :start nil :component nil))
673 (tail (make-block-key :start nil :component nil))
674 (res (make-component head tail)))
675 (setf (block-flag head) t)
676 (setf (block-flag tail) t)
677 (setf (block-component head) res)
678 (setf (block-component tail) res)
679 (setf (block-next head) tail)
680 (setf (block-prev tail) head)
683 ;;; Make NODE the LAST node in its block, splitting the block if necessary.
684 ;;; The new block is added to the DFO immediately following NODE's block.
685 (defun node-ends-block (node)
686 (declare (type node node))
687 (let* ((block (node-block node))
688 (start (node-next node))
689 (last (block-last block)))
690 (unless (eq last node)
691 (aver (and (eq (ctran-kind start) :inside-block)
692 (not (block-delete-p block))))
693 (let* ((succ (block-succ block))
695 (make-block-key :start start
696 :component (block-component block)
697 :succ succ :last last)))
698 (setf (ctran-kind start) :block-start)
699 (setf (ctran-use start) nil)
700 (setf (block-last block) node)
701 (setf (node-next node) nil)
704 (cons new-block (remove block (block-pred b)))))
705 (setf (block-succ block) ())
706 (link-blocks block new-block)
707 (add-to-dfo new-block block)
708 (setf (component-reanalyze (block-component block)) t)
710 (do ((ctran start (node-next (ctran-next ctran))))
712 (setf (ctran-block ctran) new-block))
714 (setf (block-type-asserted block) t)
715 (setf (block-test-modified block) t))))
720 ;;; Deal with deleting the last (read) reference to a LAMBDA-VAR.
721 (defun delete-lambda-var (leaf)
722 (declare (type lambda-var leaf))
724 ;; Iterate over all local calls flushing the corresponding argument,
725 ;; allowing the computation of the argument to be deleted. We also
726 ;; mark the LET for reoptimization, since it may be that we have
727 ;; deleted its last variable.
728 (let* ((fun (lambda-var-home leaf))
729 (n (position leaf (lambda-vars fun))))
730 (dolist (ref (leaf-refs fun))
731 (let* ((lvar (node-lvar ref))
732 (dest (and lvar (lvar-dest lvar))))
733 (when (and (combination-p dest)
734 (eq (basic-combination-fun dest) lvar)
735 (eq (basic-combination-kind dest) :local))
736 (let* ((args (basic-combination-args dest))
738 (reoptimize-lvar arg)
740 (setf (elt args n) nil))))))
742 ;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
743 ;; too much difficulty, since we can efficiently implement
744 ;; write-only variables. We iterate over the SETs, marking their
745 ;; blocks for dead code flushing, since we can delete SETs whose
747 (dolist (set (lambda-var-sets leaf))
748 (setf (block-flush-p (node-block set)) t))
752 ;;; Note that something interesting has happened to VAR.
753 (defun reoptimize-lambda-var (var)
754 (declare (type lambda-var var))
755 (let ((fun (lambda-var-home var)))
756 ;; We only deal with LET variables, marking the corresponding
757 ;; initial value arg as needing to be reoptimized.
758 (when (and (eq (functional-kind fun) :let)
760 (do ((args (basic-combination-args
761 (lvar-dest (node-lvar (first (leaf-refs fun)))))
763 (vars (lambda-vars fun) (cdr vars)))
765 (reoptimize-lvar (car args))))))
768 ;;; Delete a function that has no references. This need only be called
769 ;;; on functions that never had any references, since otherwise
770 ;;; DELETE-REF will handle the deletion.
771 (defun delete-functional (fun)
772 (aver (and (null (leaf-refs fun))
773 (not (functional-entry-fun fun))))
775 (optional-dispatch (delete-optional-dispatch fun))
776 (clambda (delete-lambda fun)))
779 ;;; Deal with deleting the last reference to a CLAMBDA. Since there is
780 ;;; only one way into a CLAMBDA, deleting the last reference to a
781 ;;; CLAMBDA ensures that there is no way to reach any of the code in
782 ;;; it. So we just set the FUNCTIONAL-KIND for FUN and its LETs to
783 ;;; :DELETED, causing IR1 optimization to delete blocks in that
785 (defun delete-lambda (clambda)
786 (declare (type clambda clambda))
787 (let ((original-kind (functional-kind clambda))
788 (bind (lambda-bind clambda)))
789 (aver (not (member original-kind '(:deleted :optional :toplevel))))
790 (aver (not (functional-has-external-references-p clambda)))
791 (setf (functional-kind clambda) :deleted)
792 (setf (lambda-bind clambda) nil)
793 (dolist (let (lambda-lets clambda))
794 (setf (lambda-bind let) nil)
795 (setf (functional-kind let) :deleted))
797 ;; LET may be deleted if its BIND is unreachable. Autonomous
798 ;; function may be deleted if it has no reachable references.
799 (unless (member original-kind '(:let :mv-let :assignment))
800 (dolist (ref (lambda-refs clambda))
801 (mark-for-deletion (node-block ref))))
803 ;; (The IF test is (FUNCTIONAL-SOMEWHAT-LETLIKE-P CLAMBDA), except
804 ;; that we're using the old value of the KIND slot, not the
805 ;; current slot value, which has now been set to :DELETED.)
806 (if (member original-kind '(:let :mv-let :assignment))
807 (let ((home (lambda-home clambda)))
808 (setf (lambda-lets home) (delete clambda (lambda-lets home))))
809 ;; If the function isn't a LET, we unlink the function head
810 ;; and tail from the component head and tail to indicate that
811 ;; the code is unreachable. We also delete the function from
812 ;; COMPONENT-LAMBDAS (it won't be there before local call
813 ;; analysis, but no matter.) If the lambda was never
814 ;; referenced, we give a note.
815 (let* ((bind-block (node-block bind))
816 (component (block-component bind-block))
817 (return (lambda-return clambda))
818 (return-block (and return (node-block return))))
819 (unless (leaf-ever-used clambda)
820 (let ((*compiler-error-context* bind))
821 (compiler-notify 'code-deletion-note
822 :format-control "deleting unused function~:[.~;~:*~% ~S~]"
823 :format-arguments (list (leaf-debug-name clambda)))))
824 (unless (block-delete-p bind-block)
825 (unlink-blocks (component-head component) bind-block))
826 (when (and return-block (not (block-delete-p return-block)))
827 (mark-for-deletion return-block)
828 (unlink-blocks return-block (component-tail component)))
829 (setf (component-reanalyze component) t)
830 (let ((tails (lambda-tail-set clambda)))
831 (setf (tail-set-funs tails)
832 (delete clambda (tail-set-funs tails)))
833 (setf (lambda-tail-set clambda) nil))
834 (setf (component-lambdas component)
835 (delete clambda (component-lambdas component)))))
837 ;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
838 ;; ENTRY-FUN so that people will know that it is not an entry
840 (when (eq original-kind :external)
841 (let ((fun (functional-entry-fun clambda)))
842 (setf (functional-entry-fun fun) nil)
843 (when (optional-dispatch-p fun)
844 (delete-optional-dispatch fun)))))
848 ;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
849 ;;; have to be a bit more careful than with lambdas, since DELETE-REF
850 ;;; is used both before and after local call analysis. Afterward, all
851 ;;; references to still-existing OPTIONAL-DISPATCHes have been moved
852 ;;; to the XEP, leaving it with no references at all. So we look at
853 ;;; the XEP to see whether an optional-dispatch is still really being
854 ;;; used. But before local call analysis, there are no XEPs, and all
855 ;;; references are direct.
857 ;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
858 ;;; entry-points, making them be normal lambdas, and then deleting the
859 ;;; ones with no references. This deletes any e-p lambdas that were
860 ;;; either never referenced, or couldn't be deleted when the last
861 ;;; reference was deleted (due to their :OPTIONAL kind.)
863 ;;; Note that the last optional entry point may alias the main entry,
864 ;;; so when we process the main entry, its KIND may have been changed
865 ;;; to NIL or even converted to a LETlike value.
866 (defun delete-optional-dispatch (leaf)
867 (declare (type optional-dispatch leaf))
868 (let ((entry (functional-entry-fun leaf)))
869 (unless (and entry (leaf-refs entry))
870 (aver (or (not entry) (eq (functional-kind entry) :deleted)))
871 (setf (functional-kind leaf) :deleted)
874 (unless (eq (functional-kind fun) :deleted)
875 (aver (eq (functional-kind fun) :optional))
876 (setf (functional-kind fun) nil)
877 (let ((refs (leaf-refs fun)))
881 (or (maybe-let-convert fun)
882 (maybe-convert-to-assignment fun)))
884 (maybe-convert-to-assignment fun)))))))
886 (dolist (ep (optional-dispatch-entry-points leaf))
887 (when (promise-ready-p ep)
889 (when (optional-dispatch-more-entry leaf)
890 (frob (optional-dispatch-more-entry leaf)))
891 (let ((main (optional-dispatch-main-entry leaf)))
892 (when (eq (functional-kind main) :optional)
897 ;;; Do stuff to delete the semantic attachments of a REF node. When
898 ;;; this leaves zero or one reference, we do a type dispatch off of
899 ;;; the leaf to determine if a special action is appropriate.
900 (defun delete-ref (ref)
901 (declare (type ref ref))
902 (let* ((leaf (ref-leaf ref))
903 (refs (delq ref (leaf-refs leaf))))
904 (setf (leaf-refs leaf) refs)
909 (delete-lambda-var leaf))
911 (ecase (functional-kind leaf)
912 ((nil :let :mv-let :assignment :escape :cleanup)
913 (aver (null (functional-entry-fun leaf)))
914 (delete-lambda leaf))
916 (delete-lambda leaf))
917 ((:deleted :optional))))
919 (unless (eq (functional-kind leaf) :deleted)
920 (delete-optional-dispatch leaf)))))
923 (clambda (or (maybe-let-convert leaf)
924 (maybe-convert-to-assignment leaf)))
925 (lambda-var (reoptimize-lambda-var leaf))))
928 (clambda (maybe-convert-to-assignment leaf))))))
932 ;;; This function is called by people who delete nodes; it provides a
933 ;;; way to indicate that the value of a lvar is no longer used. We
934 ;;; null out the LVAR-DEST, set FLUSH-P in the blocks containing uses
935 ;;; of LVAR and set COMPONENT-REOPTIMIZE.
936 (defun flush-dest (lvar)
937 (declare (type (or lvar null) lvar))
939 (setf (lvar-dest lvar) nil)
940 (flush-lvar-externally-checkable-type lvar)
942 (let ((prev (node-prev use)))
943 (let ((block (ctran-block prev)))
944 (setf (component-reoptimize (block-component block)) t)
945 (setf (block-attributep (block-flags block) flush-p type-asserted)
947 (setf (node-lvar use) nil))
948 (setf (lvar-uses lvar) nil))
951 (defun delete-dest (lvar)
953 (let* ((dest (lvar-dest lvar))
954 (prev (node-prev dest)))
955 (let ((block (ctran-block prev)))
956 (unless (block-delete-p block)
957 (mark-for-deletion block))))))
959 ;;; Do a graph walk backward from BLOCK, marking all predecessor
960 ;;; blocks with the DELETE-P flag.
961 (defun mark-for-deletion (block)
962 (declare (type cblock block))
963 (let* ((component (block-component block))
964 (head (component-head component)))
965 (labels ((helper (block)
966 (setf (block-delete-p block) t)
967 (dolist (pred (block-pred block))
968 (unless (or (block-delete-p pred)
971 (unless (block-delete-p block)
973 (setf (component-reanalyze component) t))))
976 ;;; This function does what is necessary to eliminate the code in it
977 ;;; from the IR1 representation. This involves unlinking it from its
978 ;;; predecessors and successors and deleting various node-specific
979 ;;; semantic information.
980 (defun delete-block (block &optional silent)
981 (declare (type cblock block))
982 (aver (block-component block)) ; else block is already deleted!
984 (note-block-deletion block))
985 (setf (block-delete-p block) t)
987 (dolist (b (block-pred block))
988 (unlink-blocks b block)
989 ;; In bug 147 the almost-all-blocks-have-a-successor invariant was
990 ;; broken when successors were deleted without setting the
991 ;; BLOCK-DELETE-P flags of their predececessors. Make sure that
992 ;; doesn't happen again.
993 (aver (not (and (null (block-succ b))
994 (not (block-delete-p b))
995 (not (eq b (component-head (block-component b))))))))
996 (dolist (b (block-succ block))
997 (unlink-blocks block b))
999 (do-nodes-carefully (node block)
1000 (when (valued-node-p node)
1001 (delete-lvar-use node))
1003 (ref (delete-ref node))
1004 (cif (flush-dest (if-test node)))
1005 ;; The next two cases serve to maintain the invariant that a LET
1006 ;; always has a well-formed COMBINATION, REF and BIND. We delete
1007 ;; the lambda whenever we delete any of these, but we must be
1008 ;; careful that this LET has not already been partially deleted.
1010 (when (and (eq (basic-combination-kind node) :local)
1011 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
1012 (lvar-uses (basic-combination-fun node)))
1013 (let ((fun (combination-lambda node)))
1014 ;; If our REF was the second-to-last ref, and has been
1015 ;; deleted, then FUN may be a LET for some other
1017 (when (and (functional-letlike-p fun)
1018 (eq (let-combination fun) node))
1019 (delete-lambda fun))))
1020 (flush-dest (basic-combination-fun node))
1021 (dolist (arg (basic-combination-args node))
1022 (when arg (flush-dest arg))))
1024 (let ((lambda (bind-lambda node)))
1025 (unless (eq (functional-kind lambda) :deleted)
1026 (delete-lambda lambda))))
1028 (let ((value (exit-value node))
1029 (entry (exit-entry node)))
1033 (setf (entry-exits entry)
1034 (delq node (entry-exits entry))))))
1036 (flush-dest (return-result node))
1037 (delete-return node))
1039 (flush-dest (set-value node))
1040 (let ((var (set-var node)))
1041 (setf (basic-var-sets var)
1042 (delete node (basic-var-sets var)))))
1044 (flush-dest (cast-value node)))))
1046 (remove-from-dfo block)
1049 ;;; Do stuff to indicate that the return node NODE is being deleted.
1050 (defun delete-return (node)
1051 (declare (type creturn node))
1052 (let* ((fun (return-lambda node))
1053 (tail-set (lambda-tail-set fun)))
1054 (aver (lambda-return fun))
1055 (setf (lambda-return fun) nil)
1056 (when (and tail-set (not (find-if #'lambda-return
1057 (tail-set-funs tail-set))))
1058 (setf (tail-set-type tail-set) *empty-type*)))
1061 ;;; If any of the VARS in FUN was never referenced and was not
1062 ;;; declared IGNORE, then complain.
1063 (defun note-unreferenced-vars (fun)
1064 (declare (type clambda fun))
1065 (dolist (var (lambda-vars fun))
1066 (unless (or (leaf-ever-used var)
1067 (lambda-var-ignorep var))
1068 (let ((*compiler-error-context* (lambda-bind fun)))
1069 (unless (policy *compiler-error-context* (= inhibit-warnings 3))
1070 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
1071 ;; requires this to be no more than a STYLE-WARNING.
1072 (compiler-style-warn "The variable ~S is defined but never used."
1073 (leaf-debug-name var)))
1074 (setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
1077 (defvar *deletion-ignored-objects* '(t nil))
1079 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
1080 ;;; our recursion so that we don't get lost in circular structures. We
1081 ;;; ignore the car of forms if they are a symbol (to prevent confusing
1082 ;;; function referencess with variables), and we also ignore anything
1084 (defun present-in-form (obj form depth)
1085 (declare (type (integer 0 20) depth))
1086 (cond ((= depth 20) nil)
1090 (let ((first (car form))
1092 (if (member first '(quote function))
1094 (or (and (not (symbolp first))
1095 (present-in-form obj first depth))
1096 (do ((l (cdr form) (cdr l))
1098 ((or (atom l) (> n 100))
1100 (declare (fixnum n))
1101 (when (present-in-form obj (car l) depth)
1104 ;;; This function is called on a block immediately before we delete
1105 ;;; it. We check to see whether any of the code about to die appeared
1106 ;;; in the original source, and emit a note if so.
1108 ;;; If the block was in a lambda is now deleted, then we ignore the
1109 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
1110 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
1111 ;;; reasonable for a function to not return, and there is a different
1112 ;;; note for that case anyway.
1114 ;;; If the actual source is an atom, then we use a bunch of heuristics
1115 ;;; to guess whether this reference really appeared in the original
1117 ;;; -- If a symbol, it must be interned and not a keyword.
1118 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
1119 ;;; or a character.)
1120 ;;; -- The atom must be "present" in the original source form, and
1121 ;;; present in all intervening actual source forms.
1122 (defun note-block-deletion (block)
1123 (let ((home (block-home-lambda block)))
1124 (unless (eq (functional-kind home) :deleted)
1125 (do-nodes (node nil block)
1126 (let* ((path (node-source-path node))
1127 (first (first path)))
1128 (when (or (eq first 'original-source-start)
1130 (or (not (symbolp first))
1131 (let ((pkg (symbol-package first)))
1133 (not (eq pkg (symbol-package :end))))))
1134 (not (member first *deletion-ignored-objects*))
1135 (not (typep first '(or fixnum character)))
1137 (present-in-form first x 0))
1138 (source-path-forms path))
1139 (present-in-form first (find-original-source path)
1141 (unless (return-p node)
1142 (let ((*compiler-error-context* node))
1143 (compiler-notify 'code-deletion-note
1144 :format-control "deleting unreachable code"
1145 :format-arguments nil)))
1149 ;;; Delete a node from a block, deleting the block if there are no
1150 ;;; nodes left. We remove the node from the uses of its LVAR.
1152 ;;; If the node is the last node, there must be exactly one successor.
1153 ;;; We link all of our precedessors to the successor and unlink the
1154 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1155 ;;; left, and the block is a successor of itself, then we replace the
1156 ;;; only node with a degenerate exit node. This provides a way to
1157 ;;; represent the bodyless infinite loop, given the prohibition on
1158 ;;; empty blocks in IR1.
1159 (defun unlink-node (node)
1160 (declare (type node node))
1161 (when (valued-node-p node)
1162 (delete-lvar-use node))
1164 (let* ((ctran (node-next node))
1165 (next (and ctran (ctran-next ctran)))
1166 (prev (node-prev node))
1167 (block (ctran-block prev))
1168 (prev-kind (ctran-kind prev))
1169 (last (block-last block)))
1171 (setf (block-type-asserted block) t)
1172 (setf (block-test-modified block) t)
1174 (cond ((or (eq prev-kind :inside-block)
1175 (and (eq prev-kind :block-start)
1176 (not (eq node last))))
1177 (cond ((eq node last)
1178 (setf (block-last block) (ctran-use prev))
1179 (setf (node-next (ctran-use prev)) nil))
1181 (setf (ctran-next prev) next)
1182 (setf (node-prev next) prev)
1183 (when (if-p next) ; AOP wanted
1184 (reoptimize-lvar (if-test next)))))
1185 (setf (node-prev node) nil)
1188 (aver (eq prev-kind :block-start))
1189 (aver (eq node last))
1190 (let* ((succ (block-succ block))
1191 (next (first succ)))
1192 (aver (singleton-p succ))
1194 ((eq block (first succ))
1195 (with-ir1-environment-from-node node
1196 (let ((exit (make-exit)))
1197 (setf (ctran-next prev) nil)
1198 (link-node-to-previous-ctran exit prev)
1199 (setf (block-last block) exit)))
1200 (setf (node-prev node) nil)
1203 (aver (eq (block-start-cleanup block)
1204 (block-end-cleanup block)))
1205 (unlink-blocks block next)
1206 (dolist (pred (block-pred block))
1207 (change-block-successor pred block next))
1208 (remove-from-dfo block)
1209 (setf (block-delete-p block) t)
1210 (setf (node-prev node) nil)
1213 ;;; Return true if NODE has been deleted, false if it is still a valid
1215 (defun node-deleted (node)
1216 (declare (type node node))
1217 (let ((prev (node-prev node)))
1219 (let ((block (ctran-block prev)))
1220 (and (block-component block)
1221 (not (block-delete-p block))))))))
1223 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1224 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1225 ;;; triggered by deletion.
1226 (defun delete-component (component)
1227 (declare (type component component))
1228 (aver (null (component-new-functionals component)))
1229 (setf (component-kind component) :deleted)
1230 (do-blocks (block component)
1231 (setf (block-delete-p block) t))
1232 (dolist (fun (component-lambdas component))
1233 (setf (functional-kind fun) nil)
1234 (setf (functional-entry-fun fun) nil)
1235 (setf (leaf-refs fun) nil)
1236 (delete-functional fun))
1237 (do-blocks (block component)
1238 (delete-block block))
1241 ;;; Convert code of the form
1242 ;;; (FOO ... (FUN ...) ...)
1244 ;;; (FOO ... ... ...).
1245 ;;; In other words, replace the function combination FUN by its
1246 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1247 ;;; to blow out of whatever transform called this. Note, as the number
1248 ;;; of arguments changes, the transform must be prepared to return a
1249 ;;; lambda with a new lambda-list with the correct number of
1251 (defun extract-fun-args (lvar fun num-args)
1253 "If CONT is a call to FUN with NUM-ARGS args, change those arguments
1254 to feed directly to the LVAR-DEST of LVAR, which must be a
1256 (declare (type lvar lvar)
1258 (type index num-args))
1259 (let ((outside (lvar-dest lvar))
1260 (inside (lvar-uses lvar)))
1261 (aver (combination-p outside))
1262 (unless (combination-p inside)
1263 (give-up-ir1-transform))
1264 (let ((inside-fun (combination-fun inside)))
1265 (unless (eq (lvar-fun-name inside-fun) fun)
1266 (give-up-ir1-transform))
1267 (let ((inside-args (combination-args inside)))
1268 (unless (= (length inside-args) num-args)
1269 (give-up-ir1-transform))
1270 (let* ((outside-args (combination-args outside))
1271 (arg-position (position lvar outside-args))
1272 (before-args (subseq outside-args 0 arg-position))
1273 (after-args (subseq outside-args (1+ arg-position))))
1274 (dolist (arg inside-args)
1275 (setf (lvar-dest arg) outside)
1276 (flush-lvar-externally-checkable-type arg))
1277 (setf (combination-args inside) nil)
1278 (setf (combination-args outside)
1279 (append before-args inside-args after-args))
1280 (change-ref-leaf (lvar-uses inside-fun)
1281 (find-free-fun 'list "???"))
1282 (setf (combination-kind inside)
1283 (info :function :info 'list))
1284 (setf (node-derived-type inside) *wild-type*)
1288 (defun flush-combination (combination)
1289 (declare (type combination combination))
1290 (flush-dest (combination-fun combination))
1291 (dolist (arg (combination-args combination))
1293 (unlink-node combination)
1299 ;;; Change the LEAF that a REF refers to.
1300 (defun change-ref-leaf (ref leaf)
1301 (declare (type ref ref) (type leaf leaf))
1302 (unless (eq (ref-leaf ref) leaf)
1303 (push ref (leaf-refs leaf))
1305 (setf (ref-leaf ref) leaf)
1306 (setf (leaf-ever-used leaf) t)
1307 (let* ((ltype (leaf-type leaf))
1308 (vltype (make-single-value-type ltype)))
1309 (if (let* ((lvar (node-lvar ref))
1310 (dest (and lvar (lvar-dest lvar))))
1311 (and (basic-combination-p dest)
1312 (eq lvar (basic-combination-fun dest))
1313 (csubtypep ltype (specifier-type 'function))))
1314 (setf (node-derived-type ref) vltype)
1315 (derive-node-type ref vltype)))
1316 (reoptimize-lvar (node-lvar ref)))
1319 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1320 (defun substitute-leaf (new-leaf old-leaf)
1321 (declare (type leaf new-leaf old-leaf))
1322 (dolist (ref (leaf-refs old-leaf))
1323 (change-ref-leaf ref new-leaf))
1326 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1327 ;;; whether to substitute
1328 (defun substitute-leaf-if (test new-leaf old-leaf)
1329 (declare (type leaf new-leaf old-leaf) (type function test))
1330 (dolist (ref (leaf-refs old-leaf))
1331 (when (funcall test ref)
1332 (change-ref-leaf ref new-leaf)))
1335 ;;; Return a LEAF which represents the specified constant object. If
1336 ;;; the object is not in *CONSTANTS*, then we create a new constant
1337 ;;; LEAF and enter it.
1338 (defun find-constant (object)
1340 ;; FIXME: What is the significance of this test? ("things
1341 ;; that are worth uniquifying"?)
1342 '(or symbol number character instance))
1343 (or (gethash object *constants*)
1344 (setf (gethash object *constants*)
1345 (make-constant :value object
1346 :%source-name '.anonymous.
1347 :type (ctype-of object)
1348 :where-from :defined)))
1349 (make-constant :value object
1350 :%source-name '.anonymous.
1351 :type (ctype-of object)
1352 :where-from :defined)))
1354 ;;; Return true if VAR would have to be closed over if environment
1355 ;;; analysis ran now (i.e. if there are any uses that have a different
1356 ;;; home lambda than VAR's home.)
1357 (defun closure-var-p (var)
1358 (declare (type lambda-var var))
1359 (let ((home (lambda-var-home var)))
1360 (cond ((eq (functional-kind home) :deleted)
1362 (t (let ((home (lambda-home home)))
1365 :key #'node-home-lambda
1367 (or (frob (leaf-refs var))
1368 (frob (basic-var-sets var)))))))))
1370 ;;; If there is a non-local exit noted in ENTRY's environment that
1371 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1372 (defun find-nlx-info (exit)
1373 (declare (type exit exit))
1374 (let* ((entry (exit-entry exit))
1375 (entry-cleanup (entry-cleanup entry)))
1376 (dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
1377 (when (eq (nlx-info-exit nlx) exit)
1380 ;;;; functional hackery
1382 (declaim (ftype (sfunction (functional) clambda) main-entry))
1383 (defun main-entry (functional)
1384 (etypecase functional
1385 (clambda functional)
1387 (optional-dispatch-main-entry functional))))
1389 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1390 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1391 ;;; optional with null default and no SUPPLIED-P. There must be a
1392 ;;; &REST arg with no references.
1393 (declaim (ftype (sfunction (functional) boolean) looks-like-an-mv-bind))
1394 (defun looks-like-an-mv-bind (functional)
1395 (and (optional-dispatch-p functional)
1396 (do ((arg (optional-dispatch-arglist functional) (cdr arg)))
1398 (let ((info (lambda-var-arg-info (car arg))))
1399 (unless info (return nil))
1400 (case (arg-info-kind info)
1402 (when (or (arg-info-supplied-p info) (arg-info-default info))
1405 (return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
1409 ;;; Return true if function is an external entry point. This is true
1410 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1411 ;;; (:TOPLEVEL kind.)
1413 (declare (type functional fun))
1414 (not (null (member (functional-kind fun) '(:external :toplevel)))))
1416 ;;; If LVAR's only use is a non-notinline global function reference,
1417 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1418 ;;; is true, then we don't care if the leaf is NOTINLINE.
1419 (defun lvar-fun-name (lvar &optional notinline-ok)
1420 (declare (type lvar lvar))
1421 (let ((use (lvar-uses lvar)))
1423 (let ((leaf (ref-leaf use)))
1424 (if (and (global-var-p leaf)
1425 (eq (global-var-kind leaf) :global-function)
1426 (or (not (defined-fun-p leaf))
1427 (not (eq (defined-fun-inlinep leaf) :notinline))
1429 (leaf-source-name leaf)
1433 ;;; Return the source name of a combination. (This is an idiom
1434 ;;; which was used in CMU CL. I gather it always works. -- WHN)
1435 (defun combination-fun-source-name (combination)
1436 (let ((ref (lvar-uses (combination-fun combination))))
1437 (leaf-source-name (ref-leaf ref))))
1439 ;;; Return the COMBINATION node that is the call to the LET FUN.
1440 (defun let-combination (fun)
1441 (declare (type clambda fun))
1442 (aver (functional-letlike-p fun))
1443 (lvar-dest (node-lvar (first (leaf-refs fun)))))
1445 ;;; Return the initial value continuation for a LET variable, or NIL
1446 ;;; if there is none.
1447 (defun let-var-initial-value (var)
1448 (declare (type lambda-var var))
1449 (let ((fun (lambda-var-home var)))
1450 (elt (combination-args (let-combination fun))
1451 (position-or-lose var (lambda-vars fun)))))
1453 ;;; Return the LAMBDA that is called by the local CALL.
1454 (defun combination-lambda (call)
1455 (declare (type basic-combination call))
1456 (aver (eq (basic-combination-kind call) :local))
1457 (ref-leaf (lvar-uses (basic-combination-fun call))))
1459 (defvar *inline-expansion-limit* 200
1461 "an upper limit on the number of inline function calls that will be expanded
1462 in any given code object (single function or block compilation)")
1464 ;;; Check whether NODE's component has exceeded its inline expansion
1465 ;;; limit, and warn if so, returning NIL.
1466 (defun inline-expansion-ok (node)
1467 (let ((expanded (incf (component-inline-expansions
1469 (node-block node))))))
1470 (cond ((> expanded *inline-expansion-limit*) nil)
1471 ((= expanded *inline-expansion-limit*)
1472 ;; FIXME: If the objective is to stop the recursive
1473 ;; expansion of inline functions, wouldn't it be more
1474 ;; correct to look back through surrounding expansions
1475 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1476 ;; possibly stored elsewhere too) and suppress expansion
1477 ;; and print this warning when the function being proposed
1478 ;; for inline expansion is found there? (I don't like the
1479 ;; arbitrary numerical limit in principle, and I think
1480 ;; it'll be a nuisance in practice if we ever want the
1481 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1482 ;; arbitrarily huge blocks of code. -- WHN)
1483 (let ((*compiler-error-context* node))
1484 (compiler-notify "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1485 probably trying to~% ~
1486 inline a recursive function."
1487 *inline-expansion-limit*))
1491 ;;; Make sure that FUNCTIONAL is not let-converted or deleted.
1492 (defun assure-functional-live-p (functional)
1493 (declare (type functional functional))
1495 ;; looks LET-converted
1496 (functional-somewhat-letlike-p functional)
1497 ;; It's possible for a LET-converted function to end up
1498 ;; deleted later. In that case, for the purposes of this
1499 ;; analysis, it is LET-converted: LET-converted functionals
1500 ;; are too badly trashed to expand them inline, and deleted
1501 ;; LET-converted functionals are even worse.
1502 (eql (functional-kind functional) :deleted)))
1503 (throw 'locall-already-let-converted functional)))
1507 ;;; Apply a function to some arguments, returning a list of the values
1508 ;;; resulting of the evaluation. If an error is signalled during the
1509 ;;; application, then we produce a warning message using WARN-FUN and
1510 ;;; return NIL as our second value to indicate this. NODE is used as
1511 ;;; the error context for any error message, and CONTEXT is a string
1512 ;;; that is spliced into the warning.
1513 (declaim (ftype (sfunction ((or symbol function) list node function string)
1514 (values list boolean))
1516 (defun careful-call (function args node warn-fun context)
1518 (multiple-value-list
1519 (handler-case (apply function args)
1521 (let ((*compiler-error-context* node))
1522 (funcall warn-fun "Lisp error during ~A:~%~A" context condition)
1523 (return-from careful-call (values nil nil))))))
1526 ;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
1529 ((deffrob (basic careful compiler transform)
1531 (defun ,careful (specifier)
1532 (handler-case (,basic specifier)
1533 (sb!kernel::arg-count-error (condition)
1534 (values nil (list (format nil "~A" condition))))
1535 (simple-error (condition)
1536 (values nil (list* (simple-condition-format-control condition)
1537 (simple-condition-format-arguments condition))))))
1538 (defun ,compiler (specifier)
1539 (multiple-value-bind (type error-args) (,careful specifier)
1541 (apply #'compiler-error error-args))))
1542 (defun ,transform (specifier)
1543 (multiple-value-bind (type error-args) (,careful specifier)
1545 (apply #'give-up-ir1-transform
1547 (deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type)
1548 (deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type))
1551 ;;;; utilities used at run-time for parsing &KEY args in IR1
1553 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1554 ;;; the lvar for the value of the &KEY argument KEY in the list of
1555 ;;; lvars ARGS. It returns the lvar if the keyword is present, or NIL
1556 ;;; otherwise. The legality and constantness of the keywords should
1557 ;;; already have been checked.
1558 (declaim (ftype (sfunction (list keyword) (or lvar null))
1560 (defun find-keyword-lvar (args key)
1561 (do ((arg args (cddr arg)))
1563 (when (eq (lvar-value (first arg)) key)
1564 (return (second arg)))))
1566 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1567 ;;; verify that alternating lvars in ARGS are constant and that there
1568 ;;; is an even number of args.
1569 (declaim (ftype (sfunction (list) boolean) check-key-args-constant))
1570 (defun check-key-args-constant (args)
1571 (do ((arg args (cddr arg)))
1573 (unless (and (rest arg)
1574 (constant-lvar-p (first arg)))
1577 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1578 ;;; verify that the list of lvars ARGS is a well-formed &KEY arglist
1579 ;;; and that only keywords present in the list KEYS are supplied.
1580 (declaim (ftype (sfunction (list list) boolean) check-transform-keys))
1581 (defun check-transform-keys (args keys)
1582 (and (check-key-args-constant args)
1583 (do ((arg args (cddr arg)))
1585 (unless (member (lvar-value (first arg)) keys)
1590 ;;; Called by the expansion of the EVENT macro.
1591 (declaim (ftype (sfunction (event-info (or node null)) *) %event))
1592 (defun %event (info node)
1593 (incf (event-info-count info))
1594 (when (and (>= (event-info-level info) *event-note-threshold*)
1595 (policy (or node *lexenv*)
1596 (= inhibit-warnings 0)))
1597 (let ((*compiler-error-context* node))
1598 (compiler-notify (event-info-description info))))
1600 (let ((action (event-info-action info)))
1601 (when action (funcall action node))))
1604 (defun make-cast (value type policy)
1605 (declare (type lvar value)
1607 (type policy policy))
1608 (%make-cast :asserted-type type
1609 :type-to-check (maybe-weaken-check type policy)
1611 :derived-type (coerce-to-values type)))
1613 (defun cast-type-check (cast)
1614 (declare (type cast cast))
1615 (when (cast-reoptimize cast)
1616 (ir1-optimize-cast cast t))
1617 (cast-%type-check cast))
1619 (defun note-single-valuified-lvar (lvar)
1620 (declare (type (or lvar null) lvar))
1622 (let ((use (lvar-uses lvar)))
1624 (let ((leaf (ref-leaf use)))
1625 (when (and (lambda-var-p leaf)
1626 (null (rest (leaf-refs leaf))))
1627 (reoptimize-lambda-var leaf))))
1628 ((or (listp use) (combination-p use))
1629 (do-uses (node lvar)
1630 (setf (node-reoptimize node) t)
1631 (setf (block-reoptimize (node-block node)) t)
1632 (setf (component-reoptimize (node-component node)) t)))))))