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))
173 (%delete-lvar-use node)
175 (add-lvar-use node new)))
177 (when new (reoptimize-lvar new))
180 ;;;; block starting/creation
182 ;;; Return the block that CTRAN is the start of, making a block if
183 ;;; necessary. This function is called by IR1 translators which may
184 ;;; cause a CTRAN to be used more than once. Every CTRAN which may be
185 ;;; used more than once must start a block by the time that anyone
186 ;;; does a USE-CTRAN on it.
188 ;;; We also throw the block into the next/prev list for the
189 ;;; *CURRENT-COMPONENT* so that we keep track of which blocks we have
191 (defun ctran-starts-block (ctran)
192 (declare (type ctran ctran))
193 (ecase (ctran-kind ctran)
195 (aver (not (ctran-block ctran)))
196 (let* ((next (component-last-block *current-component*))
197 (prev (block-prev next))
198 (new-block (make-block ctran)))
199 (setf (block-next new-block) next
200 (block-prev new-block) prev
201 (block-prev next) new-block
202 (block-next prev) new-block
203 (ctran-block ctran) new-block
204 (ctran-kind ctran) :block-start)
205 (aver (not (ctran-use ctran)))
208 (ctran-block ctran))))
210 ;;; Ensure that CTRAN is the start of a block so that the use set can
211 ;;; be freely manipulated.
212 (defun ensure-block-start (ctran)
213 (declare (type ctran ctran))
214 (let ((kind (ctran-kind ctran)))
218 (setf (ctran-block ctran)
219 (make-block-key :start ctran))
220 (setf (ctran-kind ctran) :block-start))
222 (node-ends-block (ctran-use ctran)))))
227 ;;; Filter values of LVAR through FORM, which must be an ordinary/mv
228 ;;; call. First argument must be 'DUMMY, which will be replaced with
229 ;;; LVAR. In case of an ordinary call the function should not have
230 ;;; return type NIL. We create a new "filtered" lvar.
232 ;;; TODO: remove preconditions.
233 (defun filter-lvar (lvar form)
234 (declare (type lvar lvar) (type list form))
235 (let* ((dest (lvar-dest lvar))
236 (ctran (node-prev dest)))
237 (with-ir1-environment-from-node dest
239 (ensure-block-start ctran)
240 (let* ((old-block (ctran-block ctran))
241 (new-start (make-ctran))
242 (filtered-lvar (make-lvar))
243 (new-block (ctran-starts-block new-start)))
245 ;; Splice in the new block before DEST, giving the new block
246 ;; all of DEST's predecessors.
247 (dolist (block (block-pred old-block))
248 (change-block-successor block old-block new-block))
250 (ir1-convert new-start ctran filtered-lvar form)
252 ;; KLUDGE: Comments at the head of this function in CMU CL
253 ;; said that somewhere in here we
254 ;; Set the new block's start and end cleanups to the *start*
255 ;; cleanup of PREV's block. This overrides the incorrect
256 ;; default from WITH-IR1-ENVIRONMENT-FROM-NODE.
257 ;; Unfortunately I can't find any code which corresponds to this.
258 ;; Perhaps it was a stale comment? Or perhaps I just don't
259 ;; understand.. -- WHN 19990521
261 ;; Replace 'DUMMY with the LVAR. (We can find 'DUMMY because
262 ;; no LET conversion has been done yet.) The [mv-]combination
263 ;; code from the call in the form will be the use of the new
264 ;; check lvar. We substitute for the first argument of
266 (let* ((node (lvar-use filtered-lvar))
267 (args (basic-combination-args node))
268 (victim (first args)))
269 (aver (eq (constant-value (ref-leaf (lvar-use victim)))
272 (substitute-lvar filtered-lvar lvar)
273 (substitute-lvar lvar victim)
276 ;; Invoking local call analysis converts this call to a LET.
277 (locall-analyze-component *current-component*))))
280 ;;; Delete NODE and VALUE. It may result in some calls becoming tail.
281 (defun delete-filter (node lvar value)
282 (aver (eq (lvar-dest value) node))
283 (aver (eq (node-lvar node) lvar))
284 (cond (lvar (collect ((merges))
285 (when (return-p (lvar-dest lvar))
287 (when (and (basic-combination-p use)
288 (eq (basic-combination-kind use) :local))
290 (%delete-lvar-use node)
291 (substitute-lvar-uses lvar value)
294 (dolist (merge (merges))
295 (merge-tail-sets merge)))))
296 (t (flush-dest value)
297 (unlink-node node))))
299 ;;;; miscellaneous shorthand functions
301 ;;; Return the home (i.e. enclosing non-LET) CLAMBDA for NODE. Since
302 ;;; the LEXENV-LAMBDA may be deleted, we must chain up the
303 ;;; LAMBDA-CALL-LEXENV thread until we find a CLAMBDA that isn't
304 ;;; deleted, and then return its home.
305 (defun node-home-lambda (node)
306 (declare (type node node))
307 (do ((fun (lexenv-lambda (node-lexenv node))
308 (lexenv-lambda (lambda-call-lexenv fun))))
309 ((not (eq (functional-kind fun) :deleted))
311 (when (eq (lambda-home fun) fun)
314 #!-sb-fluid (declaim (inline node-block))
315 (defun node-block (node)
316 (ctran-block (node-prev node)))
317 (declaim (ftype (sfunction (node) component) node-component))
318 (defun node-component (node)
319 (block-component (node-block node)))
320 (declaim (ftype (sfunction (node) physenv) node-physenv))
321 (defun node-physenv (node)
322 (lambda-physenv (node-home-lambda node)))
323 #!-sb-fluid (declaim (inline node-dest))
324 (defun node-dest (node)
325 (awhen (node-lvar node) (lvar-dest it)))
327 ;;; Checks whether NODE is in a block to be deleted
328 (declaim (inline node-to-be-deleted-p))
329 (defun node-to-be-deleted-p (node)
330 (let ((block (node-block node)))
331 (or (block-delete-p block)
332 (eq (functional-kind (block-home-lambda block)) :deleted))))
334 (declaim (ftype (sfunction (clambda) cblock) lambda-block))
335 (defun lambda-block (clambda)
336 (node-block (lambda-bind clambda)))
337 (declaim (ftype (sfunction (clambda) component) lambda-component))
338 (defun lambda-component (clambda)
339 (block-component (lambda-block clambda)))
341 (declaim (ftype (sfunction (cblock) node) block-start-node))
342 (defun block-start-node (block)
343 (ctran-next (block-start block)))
345 ;;; Return the enclosing cleanup for environment of the first or last
347 (defun block-start-cleanup (block)
348 (node-enclosing-cleanup (block-start-node block)))
349 (defun block-end-cleanup (block)
350 (node-enclosing-cleanup (block-last block)))
352 ;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
353 ;;; if there is none.
355 ;;; There can legitimately be no home lambda in dead code early in the
356 ;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
357 ;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
358 ;;; where the block is just a placeholder during parsing and doesn't
359 ;;; actually correspond to code which will be written anywhere.
360 (declaim (ftype (sfunction (cblock) (or clambda null)) block-home-lambda-or-null))
361 (defun block-home-lambda-or-null (block)
362 (if (node-p (block-last block))
363 ;; This is the old CMU CL way of doing it.
364 (node-home-lambda (block-last block))
365 ;; Now that SBCL uses this operation more aggressively than CMU
366 ;; CL did, the old CMU CL way of doing it can fail in two ways.
367 ;; 1. It can fail in a few cases even when a meaningful home
368 ;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
370 ;; 2. It can fail when converting a form which is born orphaned
371 ;; so that it never had a meaningful home lambda, e.g. a form
372 ;; which follows a RETURN-FROM or GO form.
373 (let ((pred-list (block-pred block)))
374 ;; To deal with case 1, we reason that
375 ;; previous-in-target-execution-order blocks should be in the
376 ;; same lambda, and that they seem in practice to be
377 ;; previous-in-compilation-order blocks too, so we look back
378 ;; to find one which is sufficiently initialized to tell us
379 ;; what the home lambda is.
381 ;; We could get fancy about this, flooding through the
382 ;; graph of all the previous blocks, but in practice it
383 ;; seems to work just to grab the first previous block and
385 (node-home-lambda (block-last (first pred-list)))
386 ;; In case 2, we end up with an empty PRED-LIST and
387 ;; have to punt: There's no home lambda.
390 ;;; Return the non-LET LAMBDA that holds BLOCK's code.
391 (declaim (ftype (sfunction (cblock) clambda) block-home-lambda))
392 (defun block-home-lambda (block)
393 (block-home-lambda-or-null block))
395 ;;; Return the IR1 physical environment for BLOCK.
396 (declaim (ftype (sfunction (cblock) physenv) block-physenv))
397 (defun block-physenv (block)
398 (lambda-physenv (block-home-lambda block)))
400 ;;; Return the Top Level Form number of PATH, i.e. the ordinal number
401 ;;; of its original source's top level form in its compilation unit.
402 (defun source-path-tlf-number (path)
403 (declare (list path))
406 ;;; Return the (reversed) list for the PATH in the original source
407 ;;; (with the Top Level Form number last).
408 (defun source-path-original-source (path)
409 (declare (list path) (inline member))
410 (cddr (member 'original-source-start path :test #'eq)))
412 ;;; Return the Form Number of PATH's original source inside the Top
413 ;;; Level Form that contains it. This is determined by the order that
414 ;;; we walk the subforms of the top level source form.
415 (defun source-path-form-number (path)
416 (declare (list path) (inline member))
417 (cadr (member 'original-source-start path :test #'eq)))
419 ;;; Return a list of all the enclosing forms not in the original
420 ;;; source that converted to get to this form, with the immediate
421 ;;; source for node at the start of the list.
422 (defun source-path-forms (path)
423 (subseq path 0 (position 'original-source-start path)))
425 ;;; Return the innermost source form for NODE.
426 (defun node-source-form (node)
427 (declare (type node node))
428 (let* ((path (node-source-path node))
429 (forms (source-path-forms path)))
432 (values (find-original-source path)))))
434 ;;; Return NODE-SOURCE-FORM, T if lvar has a single use, otherwise
436 (defun lvar-source (lvar)
437 (let ((use (lvar-uses lvar)))
440 (values (node-source-form use) t))))
442 ;;; Return the unique node, delivering a value to LVAR.
443 #!-sb-fluid (declaim (inline lvar-use))
444 (defun lvar-use (lvar)
445 (the (not list) (lvar-uses lvar)))
447 #!-sb-fluid (declaim (inline lvar-has-single-use-p))
448 (defun lvar-has-single-use-p (lvar)
449 (typep (lvar-uses lvar) '(not list)))
451 ;;; Return the LAMBDA that is CTRAN's home, or NIL if there is none.
452 (declaim (ftype (sfunction (ctran) (or clambda null))
453 ctran-home-lambda-or-null))
454 (defun ctran-home-lambda-or-null (ctran)
455 ;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
456 ;; implementation might not be quite right, or might be uglier than
457 ;; necessary. It appears that the original Python never found a need
458 ;; to do this operation. The obvious things based on
459 ;; NODE-HOME-LAMBDA of CTRAN-USE usually work; then if that fails,
460 ;; BLOCK-HOME-LAMBDA of CTRAN-BLOCK works, given that we
461 ;; generalize it enough to grovel harder when the simple CMU CL
462 ;; approach fails, and furthermore realize that in some exceptional
463 ;; cases it might return NIL. -- WHN 2001-12-04
464 (cond ((ctran-use ctran)
465 (node-home-lambda (ctran-use ctran)))
467 (block-home-lambda-or-null (ctran-block ctran)))
469 (bug "confused about home lambda for ~S" ctran))))
471 ;;; Return the LAMBDA that is CTRAN's home.
472 (declaim (ftype (sfunction (ctran) clambda) ctran-home-lambda))
473 (defun ctran-home-lambda (ctran)
474 (ctran-home-lambda-or-null ctran))
476 #!-sb-fluid (declaim (inline lvar-single-value-p))
477 (defun lvar-single-value-p (lvar)
479 (let ((dest (lvar-dest lvar)))
484 (eq (basic-combination-fun dest) lvar))
487 (declare (notinline lvar-single-value-p))
488 (and (not (values-type-p (cast-asserted-type dest)))
489 (lvar-single-value-p (node-lvar dest)))))
493 (defun principal-lvar-end (lvar)
494 (loop for prev = lvar then (node-lvar dest)
495 for dest = (and prev (lvar-dest prev))
497 finally (return (values dest prev))))
499 (defun principal-lvar-single-valuify (lvar)
500 (loop for prev = lvar then (node-lvar dest)
501 for dest = (and prev (lvar-dest prev))
503 do (setf (node-derived-type dest)
504 (make-short-values-type (list (single-value-type
505 (node-derived-type dest)))))
506 (reoptimize-lvar prev)))
508 ;;; Return a new LEXENV just like DEFAULT except for the specified
509 ;;; slot values. Values for the alist slots are NCONCed to the
510 ;;; beginning of the current value, rather than replacing it entirely.
511 (defun make-lexenv (&key (default *lexenv*)
512 funs vars blocks tags
514 (lambda (lexenv-lambda default))
515 (cleanup (lexenv-cleanup default))
516 (policy (lexenv-policy default)))
517 (macrolet ((frob (var slot)
518 `(let ((old (,slot default)))
522 (internal-make-lexenv
523 (frob funs lexenv-funs)
524 (frob vars lexenv-vars)
525 (frob blocks lexenv-blocks)
526 (frob tags lexenv-tags)
527 (frob type-restrictions lexenv-type-restrictions)
528 lambda cleanup policy)))
530 ;;; Makes a LEXENV, suitable for using in a MACROLET introduced
532 (defun make-restricted-lexenv (lexenv)
533 (flet ((fun-good-p (fun)
534 (destructuring-bind (name . thing) fun
535 (declare (ignore name))
539 (cons (aver (eq (car thing) 'macro))
542 (destructuring-bind (name . thing) var
543 (declare (ignore name))
546 (cons (aver (eq (car thing) 'macro))
548 (heap-alien-info nil)))))
549 (internal-make-lexenv
550 (remove-if-not #'fun-good-p (lexenv-funs lexenv))
551 (remove-if-not #'var-good-p (lexenv-vars lexenv))
554 (lexenv-type-restrictions lexenv) ; XXX
557 (lexenv-policy lexenv))))
559 ;;;; flow/DFO/component hackery
561 ;;; Join BLOCK1 and BLOCK2.
562 (defun link-blocks (block1 block2)
563 (declare (type cblock block1 block2))
564 (setf (block-succ block1)
565 (if (block-succ block1)
566 (%link-blocks block1 block2)
568 (push block1 (block-pred block2))
570 (defun %link-blocks (block1 block2)
571 (declare (type cblock block1 block2))
572 (let ((succ1 (block-succ block1)))
573 (aver (not (memq block2 succ1)))
574 (cons block2 succ1)))
576 ;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
577 ;;; this leaves a successor with a single predecessor that ends in an
578 ;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
579 ;;; now be able to be propagated to the successor.
580 (defun unlink-blocks (block1 block2)
581 (declare (type cblock block1 block2))
582 (let ((succ1 (block-succ block1)))
583 (if (eq block2 (car succ1))
584 (setf (block-succ block1) (cdr succ1))
585 (do ((succ (cdr succ1) (cdr succ))
587 ((eq (car succ) block2)
588 (setf (cdr prev) (cdr succ)))
591 (let ((new-pred (delq block1 (block-pred block2))))
592 (setf (block-pred block2) new-pred)
593 (when (singleton-p new-pred)
594 (let ((pred-block (first new-pred)))
595 (when (if-p (block-last pred-block))
596 (setf (block-test-modified pred-block) t)))))
599 ;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
600 ;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
601 ;;; consequent/alternative blocks to point to NEW. We also set
602 ;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
603 ;;; the new successor.
604 (defun change-block-successor (block old new)
605 (declare (type cblock new old block))
606 (unlink-blocks block old)
607 (let ((last (block-last block))
608 (comp (block-component block)))
609 (setf (component-reanalyze comp) t)
612 (setf (block-test-modified block) t)
613 (let* ((succ-left (block-succ block))
614 (new (if (and (eq new (component-tail comp))
618 (unless (memq new succ-left)
619 (link-blocks block new))
620 (macrolet ((frob (slot)
621 `(when (eq (,slot last) old)
622 (setf (,slot last) new))))
624 (frob if-alternative)
625 (when (eq (if-consequent last)
626 (if-alternative last))
627 (setf (component-reoptimize (block-component block)) t)))))
629 (unless (memq new (block-succ block))
630 (link-blocks block new)))))
634 ;;; Unlink a block from the next/prev chain. We also null out the
636 (declaim (ftype (sfunction (cblock) (values)) remove-from-dfo))
637 (defun remove-from-dfo (block)
638 (let ((next (block-next block))
639 (prev (block-prev block)))
640 (setf (block-component block) nil)
641 (setf (block-next prev) next)
642 (setf (block-prev next) prev))
645 ;;; Add BLOCK to the next/prev chain following AFTER. We also set the
646 ;;; COMPONENT to be the same as for AFTER.
647 (defun add-to-dfo (block after)
648 (declare (type cblock block after))
649 (let ((next (block-next after))
650 (comp (block-component after)))
651 (aver (not (eq (component-kind comp) :deleted)))
652 (setf (block-component block) comp)
653 (setf (block-next after) block)
654 (setf (block-prev block) after)
655 (setf (block-next block) next)
656 (setf (block-prev next) block))
659 ;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
660 ;;; the head and tail which are set to T.
661 (declaim (ftype (sfunction (component) (values)) clear-flags))
662 (defun clear-flags (component)
663 (let ((head (component-head component))
664 (tail (component-tail component)))
665 (setf (block-flag head) t)
666 (setf (block-flag tail) t)
667 (do-blocks (block component)
668 (setf (block-flag block) nil)))
671 ;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
672 ;;; true in the head and tail blocks.
673 (declaim (ftype (sfunction () component) make-empty-component))
674 (defun make-empty-component ()
675 (let* ((head (make-block-key :start nil :component nil))
676 (tail (make-block-key :start nil :component nil))
677 (res (make-component head tail)))
678 (setf (block-flag head) t)
679 (setf (block-flag tail) t)
680 (setf (block-component head) res)
681 (setf (block-component tail) res)
682 (setf (block-next head) tail)
683 (setf (block-prev tail) head)
686 ;;; Make NODE the LAST node in its block, splitting the block if necessary.
687 ;;; The new block is added to the DFO immediately following NODE's block.
688 (defun node-ends-block (node)
689 (declare (type node node))
690 (let* ((block (node-block node))
691 (start (node-next node))
692 (last (block-last block)))
693 (unless (eq last node)
694 (aver (and (eq (ctran-kind start) :inside-block)
695 (not (block-delete-p block))))
696 (let* ((succ (block-succ block))
698 (make-block-key :start start
699 :component (block-component block)
700 :succ succ :last last)))
701 (setf (ctran-kind start) :block-start)
702 (setf (ctran-use start) nil)
703 (setf (block-last block) node)
704 (setf (node-next node) nil)
707 (cons new-block (remove block (block-pred b)))))
708 (setf (block-succ block) ())
709 (link-blocks block new-block)
710 (add-to-dfo new-block block)
711 (setf (component-reanalyze (block-component block)) t)
713 (do ((ctran start (node-next (ctran-next ctran))))
715 (setf (ctran-block ctran) new-block))
717 (setf (block-type-asserted block) t)
718 (setf (block-test-modified block) t))))
723 ;;; Deal with deleting the last (read) reference to a LAMBDA-VAR.
724 (defun delete-lambda-var (leaf)
725 (declare (type lambda-var leaf))
727 ;; Iterate over all local calls flushing the corresponding argument,
728 ;; allowing the computation of the argument to be deleted. We also
729 ;; mark the LET for reoptimization, since it may be that we have
730 ;; deleted its last variable.
731 (let* ((fun (lambda-var-home leaf))
732 (n (position leaf (lambda-vars fun))))
733 (dolist (ref (leaf-refs fun))
734 (let* ((lvar (node-lvar ref))
735 (dest (and lvar (lvar-dest lvar))))
736 (when (and (combination-p dest)
737 (eq (basic-combination-fun dest) lvar)
738 (eq (basic-combination-kind dest) :local))
739 (let* ((args (basic-combination-args dest))
741 (reoptimize-lvar arg)
743 (setf (elt args n) nil))))))
745 ;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
746 ;; too much difficulty, since we can efficiently implement
747 ;; write-only variables. We iterate over the SETs, marking their
748 ;; blocks for dead code flushing, since we can delete SETs whose
750 (dolist (set (lambda-var-sets leaf))
751 (setf (block-flush-p (node-block set)) t))
755 ;;; Note that something interesting has happened to VAR.
756 (defun reoptimize-lambda-var (var)
757 (declare (type lambda-var var))
758 (let ((fun (lambda-var-home var)))
759 ;; We only deal with LET variables, marking the corresponding
760 ;; initial value arg as needing to be reoptimized.
761 (when (and (eq (functional-kind fun) :let)
763 (do ((args (basic-combination-args
764 (lvar-dest (node-lvar (first (leaf-refs fun)))))
766 (vars (lambda-vars fun) (cdr vars)))
768 (reoptimize-lvar (car args))))))
771 ;;; Delete a function that has no references. This need only be called
772 ;;; on functions that never had any references, since otherwise
773 ;;; DELETE-REF will handle the deletion.
774 (defun delete-functional (fun)
775 (aver (and (null (leaf-refs fun))
776 (not (functional-entry-fun fun))))
778 (optional-dispatch (delete-optional-dispatch fun))
779 (clambda (delete-lambda fun)))
782 ;;; Deal with deleting the last reference to a CLAMBDA. It is called
783 ;;; in two situations: when the lambda is unreachable (so that its
784 ;;; body may be deleted), and when it is an effectless LET (in this
785 ;;; case its body is reachable and is not completely "its"). We set
786 ;;; FUNCTIONAL-KIND to :DELETED and rely on IR1-OPTIMIZE to delete its
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 (setf (functional-kind clambda) :deleted)
795 (setf (lambda-bind clambda) nil)
797 (when bind ; CLAMBDA is deleted due to unreachability
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)))
807 (dolist (let (lambda-lets clambda))
808 (setf (lambda-bind let) nil)
809 (setf (functional-kind let) :deleted))
811 ;; LET may be deleted if its BIND is unreachable. Autonomous
812 ;; function may be deleted if it has no reachable references.
813 (unless (member original-kind '(:let :mv-let :assignment))
814 (dolist (ref (lambda-refs clambda))
815 (mark-for-deletion (node-block ref))))
817 ;; (The IF test is (FUNCTIONAL-SOMEWHAT-LETLIKE-P CLAMBDA), except
818 ;; that we're using the old value of the KIND slot, not the
819 ;; current slot value, which has now been set to :DELETED.)
820 (if (member original-kind '(:let :mv-let :assignment))
821 (let ((home (lambda-home clambda)))
822 (setf (lambda-lets home) (delete clambda (lambda-lets home))))
823 ;; If the function isn't a LET, we unlink the function head
824 ;; and tail from the component head and tail to indicate that
825 ;; the code is unreachable. We also delete the function from
826 ;; COMPONENT-LAMBDAS (it won't be there before local call
827 ;; analysis, but no matter.) If the lambda was never
828 ;; referenced, we give a note.
829 (let* ((bind-block (node-block bind))
830 (component (block-component bind-block))
831 (return (lambda-return clambda))
832 (return-block (and return (node-block return))))
833 (unless (leaf-ever-used clambda)
834 (let ((*compiler-error-context* bind))
835 (compiler-notify 'code-deletion-note
836 :format-control "deleting unused function~:[.~;~:*~% ~S~]"
837 :format-arguments (list (leaf-debug-name clambda)))))
838 (unless (block-delete-p bind-block)
839 (unlink-blocks (component-head component) bind-block))
840 (when (and return-block (not (block-delete-p return-block)))
841 (mark-for-deletion return-block)
842 (unlink-blocks return-block (component-tail component)))
843 (setf (component-reanalyze component) t)
844 (let ((tails (lambda-tail-set clambda)))
845 (setf (tail-set-funs tails)
846 (delete clambda (tail-set-funs tails)))
847 (setf (lambda-tail-set clambda) nil))
848 (setf (component-lambdas component)
849 (delq clambda (component-lambdas component)))))
851 ;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
852 ;; ENTRY-FUN so that people will know that it is not an entry
854 (when (eq original-kind :external)
855 (let ((fun (functional-entry-fun clambda)))
856 (setf (functional-entry-fun fun) nil)
857 (when (optional-dispatch-p fun)
858 (delete-optional-dispatch fun)))))
862 ;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
863 ;;; have to be a bit more careful than with lambdas, since DELETE-REF
864 ;;; is used both before and after local call analysis. Afterward, all
865 ;;; references to still-existing OPTIONAL-DISPATCHes have been moved
866 ;;; to the XEP, leaving it with no references at all. So we look at
867 ;;; the XEP to see whether an optional-dispatch is still really being
868 ;;; used. But before local call analysis, there are no XEPs, and all
869 ;;; references are direct.
871 ;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
872 ;;; entry-points, making them be normal lambdas, and then deleting the
873 ;;; ones with no references. This deletes any e-p lambdas that were
874 ;;; either never referenced, or couldn't be deleted when the last
875 ;;; reference was deleted (due to their :OPTIONAL kind.)
877 ;;; Note that the last optional entry point may alias the main entry,
878 ;;; so when we process the main entry, its KIND may have been changed
879 ;;; to NIL or even converted to a LETlike value.
880 (defun delete-optional-dispatch (leaf)
881 (declare (type optional-dispatch leaf))
882 (let ((entry (functional-entry-fun leaf)))
883 (unless (and entry (leaf-refs entry))
884 (aver (or (not entry) (eq (functional-kind entry) :deleted)))
885 (setf (functional-kind leaf) :deleted)
888 (unless (eq (functional-kind fun) :deleted)
889 (aver (eq (functional-kind fun) :optional))
890 (setf (functional-kind fun) nil)
891 (let ((refs (leaf-refs fun)))
895 (or (maybe-let-convert fun)
896 (maybe-convert-to-assignment fun)))
898 (maybe-convert-to-assignment fun)))))))
900 (dolist (ep (optional-dispatch-entry-points leaf))
901 (when (promise-ready-p ep)
903 (when (optional-dispatch-more-entry leaf)
904 (frob (optional-dispatch-more-entry leaf)))
905 (let ((main (optional-dispatch-main-entry leaf)))
906 (when (eq (functional-kind main) :optional)
911 ;;; Do stuff to delete the semantic attachments of a REF node. When
912 ;;; this leaves zero or one reference, we do a type dispatch off of
913 ;;; the leaf to determine if a special action is appropriate.
914 (defun delete-ref (ref)
915 (declare (type ref ref))
916 (let* ((leaf (ref-leaf ref))
917 (refs (delq ref (leaf-refs leaf))))
918 (setf (leaf-refs leaf) refs)
923 (delete-lambda-var leaf))
925 (ecase (functional-kind leaf)
926 ((nil :let :mv-let :assignment :escape :cleanup)
927 (aver (null (functional-entry-fun leaf)))
928 (delete-lambda leaf))
930 (delete-lambda leaf))
931 ((:deleted :optional))))
933 (unless (eq (functional-kind leaf) :deleted)
934 (delete-optional-dispatch leaf)))))
937 (clambda (or (maybe-let-convert leaf)
938 (maybe-convert-to-assignment leaf)))
939 (lambda-var (reoptimize-lambda-var leaf))))
942 (clambda (maybe-convert-to-assignment leaf))))))
946 ;;; This function is called by people who delete nodes; it provides a
947 ;;; way to indicate that the value of a lvar is no longer used. We
948 ;;; null out the LVAR-DEST, set FLUSH-P in the blocks containing uses
949 ;;; of LVAR and set COMPONENT-REOPTIMIZE.
950 (defun flush-dest (lvar)
951 (declare (type (or lvar null) lvar))
953 (setf (lvar-dest lvar) nil)
954 (flush-lvar-externally-checkable-type lvar)
956 (let ((prev (node-prev use)))
957 (let ((block (ctran-block prev)))
958 (setf (component-reoptimize (block-component block)) t)
959 (setf (block-attributep (block-flags block)
960 flush-p type-asserted type-check)
962 (setf (node-lvar use) nil))
963 (setf (lvar-uses lvar) nil))
966 (defun delete-dest (lvar)
968 (let* ((dest (lvar-dest lvar))
969 (prev (node-prev dest)))
970 (let ((block (ctran-block prev)))
971 (unless (block-delete-p block)
972 (mark-for-deletion block))))))
974 ;;; Do a graph walk backward from BLOCK, marking all predecessor
975 ;;; blocks with the DELETE-P flag.
976 (defun mark-for-deletion (block)
977 (declare (type cblock block))
978 (let* ((component (block-component block))
979 (head (component-head component)))
980 (labels ((helper (block)
981 (setf (block-delete-p block) t)
982 (dolist (pred (block-pred block))
983 (unless (or (block-delete-p pred)
986 (unless (block-delete-p block)
988 (setf (component-reanalyze component) t))))
991 ;;; This function does what is necessary to eliminate the code in it
992 ;;; from the IR1 representation. This involves unlinking it from its
993 ;;; predecessors and successors and deleting various node-specific
994 ;;; semantic information.
995 (defun delete-block (block &optional silent)
996 (declare (type cblock block))
997 (aver (block-component block)) ; else block is already deleted!
999 (note-block-deletion block))
1000 (setf (block-delete-p block) t)
1002 (dolist (b (block-pred block))
1003 (unlink-blocks b block)
1004 ;; In bug 147 the almost-all-blocks-have-a-successor invariant was
1005 ;; broken when successors were deleted without setting the
1006 ;; BLOCK-DELETE-P flags of their predececessors. Make sure that
1007 ;; doesn't happen again.
1008 (aver (not (and (null (block-succ b))
1009 (not (block-delete-p b))
1010 (not (eq b (component-head (block-component b))))))))
1011 (dolist (b (block-succ block))
1012 (unlink-blocks block b))
1014 (do-nodes-carefully (node block)
1015 (when (valued-node-p node)
1016 (delete-lvar-use node))
1018 (ref (delete-ref node))
1019 (cif (flush-dest (if-test node)))
1020 ;; The next two cases serve to maintain the invariant that a LET
1021 ;; always has a well-formed COMBINATION, REF and BIND. We delete
1022 ;; the lambda whenever we delete any of these, but we must be
1023 ;; careful that this LET has not already been partially deleted.
1025 (when (and (eq (basic-combination-kind node) :local)
1026 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
1027 (lvar-uses (basic-combination-fun node)))
1028 (let ((fun (combination-lambda node)))
1029 ;; If our REF was the second-to-last ref, and has been
1030 ;; deleted, then FUN may be a LET for some other
1032 (when (and (functional-letlike-p fun)
1033 (eq (let-combination fun) node))
1034 (delete-lambda fun))))
1035 (flush-dest (basic-combination-fun node))
1036 (dolist (arg (basic-combination-args node))
1037 (when arg (flush-dest arg))))
1039 (let ((lambda (bind-lambda node)))
1040 (unless (eq (functional-kind lambda) :deleted)
1041 (delete-lambda lambda))))
1043 (let ((value (exit-value node))
1044 (entry (exit-entry node)))
1048 (setf (entry-exits entry)
1049 (delq node (entry-exits entry))))))
1051 (dolist (exit (entry-exits node))
1052 (mark-for-deletion (node-block exit)))
1053 (let ((home (node-home-lambda node)))
1054 (setf (lambda-entries home) (delq node (lambda-entries home)))))
1056 (flush-dest (return-result node))
1057 (delete-return node))
1059 (flush-dest (set-value node))
1060 (let ((var (set-var node)))
1061 (setf (basic-var-sets var)
1062 (delete node (basic-var-sets var)))))
1064 (flush-dest (cast-value node)))))
1066 (remove-from-dfo block)
1069 ;;; Do stuff to indicate that the return node NODE is being deleted.
1070 (defun delete-return (node)
1071 (declare (type creturn node))
1072 (let* ((fun (return-lambda node))
1073 (tail-set (lambda-tail-set fun)))
1074 (aver (lambda-return fun))
1075 (setf (lambda-return fun) nil)
1076 (when (and tail-set (not (find-if #'lambda-return
1077 (tail-set-funs tail-set))))
1078 (setf (tail-set-type tail-set) *empty-type*)))
1081 ;;; If any of the VARS in FUN was never referenced and was not
1082 ;;; declared IGNORE, then complain.
1083 (defun note-unreferenced-vars (fun)
1084 (declare (type clambda fun))
1085 (dolist (var (lambda-vars fun))
1086 (unless (or (leaf-ever-used var)
1087 (lambda-var-ignorep var))
1088 (let ((*compiler-error-context* (lambda-bind fun)))
1089 (unless (policy *compiler-error-context* (= inhibit-warnings 3))
1090 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
1091 ;; requires this to be no more than a STYLE-WARNING.
1092 (compiler-style-warn "The variable ~S is defined but never used."
1093 (leaf-debug-name var)))
1094 (setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
1097 (defvar *deletion-ignored-objects* '(t nil))
1099 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
1100 ;;; our recursion so that we don't get lost in circular structures. We
1101 ;;; ignore the car of forms if they are a symbol (to prevent confusing
1102 ;;; function referencess with variables), and we also ignore anything
1104 (defun present-in-form (obj form depth)
1105 (declare (type (integer 0 20) depth))
1106 (cond ((= depth 20) nil)
1110 (let ((first (car form))
1112 (if (member first '(quote function))
1114 (or (and (not (symbolp first))
1115 (present-in-form obj first depth))
1116 (do ((l (cdr form) (cdr l))
1118 ((or (atom l) (> n 100))
1120 (declare (fixnum n))
1121 (when (present-in-form obj (car l) depth)
1124 ;;; This function is called on a block immediately before we delete
1125 ;;; it. We check to see whether any of the code about to die appeared
1126 ;;; in the original source, and emit a note if so.
1128 ;;; If the block was in a lambda is now deleted, then we ignore the
1129 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
1130 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
1131 ;;; reasonable for a function to not return, and there is a different
1132 ;;; note for that case anyway.
1134 ;;; If the actual source is an atom, then we use a bunch of heuristics
1135 ;;; to guess whether this reference really appeared in the original
1137 ;;; -- If a symbol, it must be interned and not a keyword.
1138 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
1139 ;;; or a character.)
1140 ;;; -- The atom must be "present" in the original source form, and
1141 ;;; present in all intervening actual source forms.
1142 (defun note-block-deletion (block)
1143 (let ((home (block-home-lambda block)))
1144 (unless (eq (functional-kind home) :deleted)
1145 (do-nodes (node nil block)
1146 (let* ((path (node-source-path node))
1147 (first (first path)))
1148 (when (or (eq first 'original-source-start)
1150 (or (not (symbolp first))
1151 (let ((pkg (symbol-package first)))
1153 (not (eq pkg (symbol-package :end))))))
1154 (not (member first *deletion-ignored-objects*))
1155 (not (typep first '(or fixnum character)))
1157 (present-in-form first x 0))
1158 (source-path-forms path))
1159 (present-in-form first (find-original-source path)
1161 (unless (return-p node)
1162 (let ((*compiler-error-context* node))
1163 (compiler-notify 'code-deletion-note
1164 :format-control "deleting unreachable code"
1165 :format-arguments nil)))
1169 ;;; Delete a node from a block, deleting the block if there are no
1170 ;;; nodes left. We remove the node from the uses of its LVAR.
1172 ;;; If the node is the last node, there must be exactly one successor.
1173 ;;; We link all of our precedessors to the successor and unlink the
1174 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1175 ;;; left, and the block is a successor of itself, then we replace the
1176 ;;; only node with a degenerate exit node. This provides a way to
1177 ;;; represent the bodyless infinite loop, given the prohibition on
1178 ;;; empty blocks in IR1.
1179 (defun unlink-node (node)
1180 (declare (type node node))
1181 (when (valued-node-p node)
1182 (delete-lvar-use node))
1184 (let* ((ctran (node-next node))
1185 (next (and ctran (ctran-next ctran)))
1186 (prev (node-prev node))
1187 (block (ctran-block prev))
1188 (prev-kind (ctran-kind prev))
1189 (last (block-last block)))
1191 (setf (block-type-asserted block) t)
1192 (setf (block-test-modified block) t)
1194 (cond ((or (eq prev-kind :inside-block)
1195 (and (eq prev-kind :block-start)
1196 (not (eq node last))))
1197 (cond ((eq node last)
1198 (setf (block-last block) (ctran-use prev))
1199 (setf (node-next (ctran-use prev)) nil))
1201 (setf (ctran-next prev) next)
1202 (setf (node-prev next) prev)
1203 (when (if-p next) ; AOP wanted
1204 (reoptimize-lvar (if-test next)))))
1205 (setf (node-prev node) nil)
1208 (aver (eq prev-kind :block-start))
1209 (aver (eq node last))
1210 (let* ((succ (block-succ block))
1211 (next (first succ)))
1212 (aver (singleton-p succ))
1214 ((eq block (first succ))
1215 (with-ir1-environment-from-node node
1216 (let ((exit (make-exit)))
1217 (setf (ctran-next prev) nil)
1218 (link-node-to-previous-ctran exit prev)
1219 (setf (block-last block) exit)))
1220 (setf (node-prev node) nil)
1223 (aver (eq (block-start-cleanup block)
1224 (block-end-cleanup block)))
1225 (unlink-blocks block next)
1226 (dolist (pred (block-pred block))
1227 (change-block-successor pred block next))
1228 (remove-from-dfo block)
1229 (setf (block-delete-p block) t)
1230 (setf (node-prev node) nil)
1233 ;;; Return true if NODE has been deleted, false if it is still a valid
1235 (defun node-deleted (node)
1236 (declare (type node node))
1237 (let ((prev (node-prev node)))
1239 (let ((block (ctran-block prev)))
1240 (and (block-component block)
1241 (not (block-delete-p block))))))))
1243 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1244 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1245 ;;; triggered by deletion.
1246 (defun delete-component (component)
1247 (declare (type component component))
1248 (aver (null (component-new-functionals component)))
1249 (setf (component-kind component) :deleted)
1250 (do-blocks (block component)
1251 (setf (block-delete-p block) t))
1252 (dolist (fun (component-lambdas component))
1253 (unless (eq (functional-kind fun) :deleted)
1254 (setf (functional-kind fun) nil)
1255 (setf (functional-entry-fun fun) nil)
1256 (setf (leaf-refs fun) nil)
1257 (delete-functional fun)))
1258 (do-blocks (block component)
1259 (delete-block block))
1262 ;;; Convert code of the form
1263 ;;; (FOO ... (FUN ...) ...)
1265 ;;; (FOO ... ... ...).
1266 ;;; In other words, replace the function combination FUN by its
1267 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1268 ;;; to blow out of whatever transform called this. Note, as the number
1269 ;;; of arguments changes, the transform must be prepared to return a
1270 ;;; lambda with a new lambda-list with the correct number of
1272 (defun extract-fun-args (lvar fun num-args)
1274 "If LVAR is a call to FUN with NUM-ARGS args, change those arguments
1275 to feed directly to the LVAR-DEST of LVAR, which must be a
1277 (declare (type lvar lvar)
1279 (type index num-args))
1280 (let ((outside (lvar-dest lvar))
1281 (inside (lvar-uses lvar)))
1282 (aver (combination-p outside))
1283 (unless (combination-p inside)
1284 (give-up-ir1-transform))
1285 (let ((inside-fun (combination-fun inside)))
1286 (unless (eq (lvar-fun-name inside-fun) fun)
1287 (give-up-ir1-transform))
1288 (let ((inside-args (combination-args inside)))
1289 (unless (= (length inside-args) num-args)
1290 (give-up-ir1-transform))
1291 (let* ((outside-args (combination-args outside))
1292 (arg-position (position lvar outside-args))
1293 (before-args (subseq outside-args 0 arg-position))
1294 (after-args (subseq outside-args (1+ arg-position))))
1295 (dolist (arg inside-args)
1296 (setf (lvar-dest arg) outside)
1297 (flush-lvar-externally-checkable-type arg))
1298 (setf (combination-args inside) nil)
1299 (setf (combination-args outside)
1300 (append before-args inside-args after-args))
1301 (change-ref-leaf (lvar-uses inside-fun)
1302 (find-free-fun 'list "???"))
1303 (setf (combination-kind inside)
1304 (info :function :info 'list))
1305 (setf (node-derived-type inside) *wild-type*)
1309 (defun flush-combination (combination)
1310 (declare (type combination combination))
1311 (flush-dest (combination-fun combination))
1312 (dolist (arg (combination-args combination))
1314 (unlink-node combination)
1320 ;;; Change the LEAF that a REF refers to.
1321 (defun change-ref-leaf (ref leaf)
1322 (declare (type ref ref) (type leaf leaf))
1323 (unless (eq (ref-leaf ref) leaf)
1324 (push ref (leaf-refs leaf))
1326 (setf (ref-leaf ref) leaf)
1327 (setf (leaf-ever-used leaf) t)
1328 (let* ((ltype (leaf-type leaf))
1329 (vltype (make-single-value-type ltype)))
1330 (if (let* ((lvar (node-lvar ref))
1331 (dest (and lvar (lvar-dest lvar))))
1332 (and (basic-combination-p dest)
1333 (eq lvar (basic-combination-fun dest))
1334 (csubtypep ltype (specifier-type 'function))))
1335 (setf (node-derived-type ref) vltype)
1336 (derive-node-type ref vltype)))
1337 (reoptimize-lvar (node-lvar ref)))
1340 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1341 (defun substitute-leaf (new-leaf old-leaf)
1342 (declare (type leaf new-leaf old-leaf))
1343 (dolist (ref (leaf-refs old-leaf))
1344 (change-ref-leaf ref new-leaf))
1347 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1348 ;;; whether to substitute
1349 (defun substitute-leaf-if (test new-leaf old-leaf)
1350 (declare (type leaf new-leaf old-leaf) (type function test))
1351 (dolist (ref (leaf-refs old-leaf))
1352 (when (funcall test ref)
1353 (change-ref-leaf ref new-leaf)))
1356 ;;; Return a LEAF which represents the specified constant object. If
1357 ;;; the object is not in *CONSTANTS*, then we create a new constant
1358 ;;; LEAF and enter it.
1359 (defun find-constant (object)
1361 ;; FIXME: What is the significance of this test? ("things
1362 ;; that are worth uniquifying"?)
1363 '(or symbol number character instance))
1364 (or (gethash object *constants*)
1365 (setf (gethash object *constants*)
1366 (make-constant :value object
1367 :%source-name '.anonymous.
1368 :type (ctype-of object)
1369 :where-from :defined)))
1370 (make-constant :value object
1371 :%source-name '.anonymous.
1372 :type (ctype-of object)
1373 :where-from :defined)))
1375 ;;; Return true if VAR would have to be closed over if environment
1376 ;;; analysis ran now (i.e. if there are any uses that have a different
1377 ;;; home lambda than VAR's home.)
1378 (defun closure-var-p (var)
1379 (declare (type lambda-var var))
1380 (let ((home (lambda-var-home var)))
1381 (cond ((eq (functional-kind home) :deleted)
1383 (t (let ((home (lambda-home home)))
1386 :key #'node-home-lambda
1388 (or (frob (leaf-refs var))
1389 (frob (basic-var-sets var)))))))))
1391 ;;; If there is a non-local exit noted in ENTRY's environment that
1392 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1393 (defun find-nlx-info (exit)
1394 (declare (type exit exit))
1395 (let* ((entry (exit-entry exit))
1396 (entry-cleanup (entry-cleanup entry)))
1397 (dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
1398 (when (eq (nlx-info-exit nlx) exit)
1401 ;;;; functional hackery
1403 (declaim (ftype (sfunction (functional) clambda) main-entry))
1404 (defun main-entry (functional)
1405 (etypecase functional
1406 (clambda functional)
1408 (optional-dispatch-main-entry functional))))
1410 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1411 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1412 ;;; optional with null default and no SUPPLIED-P. There must be a
1413 ;;; &REST arg with no references.
1414 (declaim (ftype (sfunction (functional) boolean) looks-like-an-mv-bind))
1415 (defun looks-like-an-mv-bind (functional)
1416 (and (optional-dispatch-p functional)
1417 (do ((arg (optional-dispatch-arglist functional) (cdr arg)))
1419 (let ((info (lambda-var-arg-info (car arg))))
1420 (unless info (return nil))
1421 (case (arg-info-kind info)
1423 (when (or (arg-info-supplied-p info) (arg-info-default info))
1426 (return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
1430 ;;; Return true if function is an external entry point. This is true
1431 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1432 ;;; (:TOPLEVEL kind.)
1434 (declare (type functional fun))
1435 (not (null (member (functional-kind fun) '(:external :toplevel)))))
1437 ;;; If LVAR's only use is a non-notinline global function reference,
1438 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1439 ;;; is true, then we don't care if the leaf is NOTINLINE.
1440 (defun lvar-fun-name (lvar &optional notinline-ok)
1441 (declare (type lvar lvar))
1442 (let ((use (lvar-uses lvar)))
1444 (let ((leaf (ref-leaf use)))
1445 (if (and (global-var-p leaf)
1446 (eq (global-var-kind leaf) :global-function)
1447 (or (not (defined-fun-p leaf))
1448 (not (eq (defined-fun-inlinep leaf) :notinline))
1450 (leaf-source-name leaf)
1454 ;;; Return the source name of a combination. (This is an idiom
1455 ;;; which was used in CMU CL. I gather it always works. -- WHN)
1456 (defun combination-fun-source-name (combination)
1457 (let ((ref (lvar-uses (combination-fun combination))))
1458 (leaf-source-name (ref-leaf ref))))
1460 ;;; Return the COMBINATION node that is the call to the LET FUN.
1461 (defun let-combination (fun)
1462 (declare (type clambda fun))
1463 (aver (functional-letlike-p fun))
1464 (lvar-dest (node-lvar (first (leaf-refs fun)))))
1466 ;;; Return the initial value lvar for a LET variable, or NIL if there
1468 (defun let-var-initial-value (var)
1469 (declare (type lambda-var var))
1470 (let ((fun (lambda-var-home var)))
1471 (elt (combination-args (let-combination fun))
1472 (position-or-lose var (lambda-vars fun)))))
1474 ;;; Return the LAMBDA that is called by the local CALL.
1475 (defun combination-lambda (call)
1476 (declare (type basic-combination call))
1477 (aver (eq (basic-combination-kind call) :local))
1478 (ref-leaf (lvar-uses (basic-combination-fun call))))
1480 (defvar *inline-expansion-limit* 200
1482 "an upper limit on the number of inline function calls that will be expanded
1483 in any given code object (single function or block compilation)")
1485 ;;; Check whether NODE's component has exceeded its inline expansion
1486 ;;; limit, and warn if so, returning NIL.
1487 (defun inline-expansion-ok (node)
1488 (let ((expanded (incf (component-inline-expansions
1490 (node-block node))))))
1491 (cond ((> expanded *inline-expansion-limit*) nil)
1492 ((= expanded *inline-expansion-limit*)
1493 ;; FIXME: If the objective is to stop the recursive
1494 ;; expansion of inline functions, wouldn't it be more
1495 ;; correct to look back through surrounding expansions
1496 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1497 ;; possibly stored elsewhere too) and suppress expansion
1498 ;; and print this warning when the function being proposed
1499 ;; for inline expansion is found there? (I don't like the
1500 ;; arbitrary numerical limit in principle, and I think
1501 ;; it'll be a nuisance in practice if we ever want the
1502 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1503 ;; arbitrarily huge blocks of code. -- WHN)
1504 (let ((*compiler-error-context* node))
1505 (compiler-notify "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1506 probably trying to~% ~
1507 inline a recursive function."
1508 *inline-expansion-limit*))
1512 ;;; Make sure that FUNCTIONAL is not let-converted or deleted.
1513 (defun assure-functional-live-p (functional)
1514 (declare (type functional functional))
1516 ;; looks LET-converted
1517 (functional-somewhat-letlike-p functional)
1518 ;; It's possible for a LET-converted function to end up
1519 ;; deleted later. In that case, for the purposes of this
1520 ;; analysis, it is LET-converted: LET-converted functionals
1521 ;; are too badly trashed to expand them inline, and deleted
1522 ;; LET-converted functionals are even worse.
1523 (eql (functional-kind functional) :deleted)))
1524 (throw 'locall-already-let-converted functional)))
1526 (defun call-full-like-p (call)
1527 (declare (type combination call))
1528 (let ((kind (basic-combination-kind call)))
1530 (and (fun-info-p kind)
1531 (not (fun-info-ir2-convert kind))
1532 (dolist (template (fun-info-templates kind) t)
1533 (when (eq (template-ltn-policy template) :fast-safe)
1534 (multiple-value-bind (val win)
1535 (valid-fun-use call (template-type template))
1536 (when (or val (not win)) (return nil)))))))))
1540 ;;; Apply a function to some arguments, returning a list of the values
1541 ;;; resulting of the evaluation. If an error is signalled during the
1542 ;;; application, then we produce a warning message using WARN-FUN and
1543 ;;; return NIL as our second value to indicate this. NODE is used as
1544 ;;; the error context for any error message, and CONTEXT is a string
1545 ;;; that is spliced into the warning.
1546 (declaim (ftype (sfunction ((or symbol function) list node function string)
1547 (values list boolean))
1549 (defun careful-call (function args node warn-fun context)
1551 (multiple-value-list
1552 (handler-case (apply function args)
1554 (let ((*compiler-error-context* node))
1555 (funcall warn-fun "Lisp error during ~A:~%~A" context condition)
1556 (return-from careful-call (values nil nil))))))
1559 ;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
1562 ((deffrob (basic careful compiler transform)
1564 (defun ,careful (specifier)
1565 (handler-case (,basic specifier)
1566 (sb!kernel::arg-count-error (condition)
1567 (values nil (list (format nil "~A" condition))))
1568 (simple-error (condition)
1569 (values nil (list* (simple-condition-format-control condition)
1570 (simple-condition-format-arguments condition))))))
1571 (defun ,compiler (specifier)
1572 (multiple-value-bind (type error-args) (,careful specifier)
1574 (apply #'compiler-error error-args))))
1575 (defun ,transform (specifier)
1576 (multiple-value-bind (type error-args) (,careful specifier)
1578 (apply #'give-up-ir1-transform
1580 (deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type)
1581 (deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type))
1584 ;;;; utilities used at run-time for parsing &KEY args in IR1
1586 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1587 ;;; the lvar for the value of the &KEY argument KEY in the list of
1588 ;;; lvars ARGS. It returns the lvar if the keyword is present, or NIL
1589 ;;; otherwise. The legality and constantness of the keywords should
1590 ;;; already have been checked.
1591 (declaim (ftype (sfunction (list keyword) (or lvar null))
1593 (defun find-keyword-lvar (args key)
1594 (do ((arg args (cddr arg)))
1596 (when (eq (lvar-value (first arg)) key)
1597 (return (second arg)))))
1599 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1600 ;;; verify that alternating lvars in ARGS are constant and that there
1601 ;;; is an even number of args.
1602 (declaim (ftype (sfunction (list) boolean) check-key-args-constant))
1603 (defun check-key-args-constant (args)
1604 (do ((arg args (cddr arg)))
1606 (unless (and (rest arg)
1607 (constant-lvar-p (first arg)))
1610 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1611 ;;; verify that the list of lvars ARGS is a well-formed &KEY arglist
1612 ;;; and that only keywords present in the list KEYS are supplied.
1613 (declaim (ftype (sfunction (list list) boolean) check-transform-keys))
1614 (defun check-transform-keys (args keys)
1615 (and (check-key-args-constant args)
1616 (do ((arg args (cddr arg)))
1618 (unless (member (lvar-value (first arg)) keys)
1623 ;;; Called by the expansion of the EVENT macro.
1624 (declaim (ftype (sfunction (event-info (or node null)) *) %event))
1625 (defun %event (info node)
1626 (incf (event-info-count info))
1627 (when (and (>= (event-info-level info) *event-note-threshold*)
1628 (policy (or node *lexenv*)
1629 (= inhibit-warnings 0)))
1630 (let ((*compiler-error-context* node))
1631 (compiler-notify (event-info-description info))))
1633 (let ((action (event-info-action info)))
1634 (when action (funcall action node))))
1637 (defun make-cast (value type policy)
1638 (declare (type lvar value)
1640 (type policy policy))
1641 (%make-cast :asserted-type type
1642 :type-to-check (maybe-weaken-check type policy)
1644 :derived-type (coerce-to-values type)))
1646 (defun cast-type-check (cast)
1647 (declare (type cast cast))
1648 (when (cast-reoptimize cast)
1649 (ir1-optimize-cast cast t))
1650 (cast-%type-check cast))
1652 (defun note-single-valuified-lvar (lvar)
1653 (declare (type (or lvar null) lvar))
1655 (let ((use (lvar-uses lvar)))
1657 (let ((leaf (ref-leaf use)))
1658 (when (and (lambda-var-p leaf)
1659 (null (rest (leaf-refs leaf))))
1660 (reoptimize-lambda-var leaf))))
1661 ((or (listp use) (combination-p use))
1662 (do-uses (node lvar)
1663 (setf (node-reoptimize node) t)
1664 (setf (block-reoptimize (node-block node)) t)
1665 (setf (component-reoptimize (node-component node)) t)))))))