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 (declaim (ftype (sfunction (clambda) cblock) lambda-block))
328 (defun lambda-block (clambda)
329 (node-block (lambda-bind clambda)))
330 (declaim (ftype (sfunction (clambda) component) lambda-component))
331 (defun lambda-component (clambda)
332 (block-component (lambda-block clambda)))
334 (declaim (ftype (sfunction (cblock) node) block-start-node))
335 (defun block-start-node (block)
336 (ctran-next (block-start block)))
338 ;;; Return the enclosing cleanup for environment of the first or last
340 (defun block-start-cleanup (block)
341 (node-enclosing-cleanup (block-start-node block)))
342 (defun block-end-cleanup (block)
343 (node-enclosing-cleanup (block-last block)))
345 ;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
346 ;;; if there is none.
348 ;;; There can legitimately be no home lambda in dead code early in the
349 ;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
350 ;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
351 ;;; where the block is just a placeholder during parsing and doesn't
352 ;;; actually correspond to code which will be written anywhere.
353 (declaim (ftype (sfunction (cblock) (or clambda null)) block-home-lambda-or-null))
354 (defun block-home-lambda-or-null (block)
355 (if (node-p (block-last block))
356 ;; This is the old CMU CL way of doing it.
357 (node-home-lambda (block-last block))
358 ;; Now that SBCL uses this operation more aggressively than CMU
359 ;; CL did, the old CMU CL way of doing it can fail in two ways.
360 ;; 1. It can fail in a few cases even when a meaningful home
361 ;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
363 ;; 2. It can fail when converting a form which is born orphaned
364 ;; so that it never had a meaningful home lambda, e.g. a form
365 ;; which follows a RETURN-FROM or GO form.
366 (let ((pred-list (block-pred block)))
367 ;; To deal with case 1, we reason that
368 ;; previous-in-target-execution-order blocks should be in the
369 ;; same lambda, and that they seem in practice to be
370 ;; previous-in-compilation-order blocks too, so we look back
371 ;; to find one which is sufficiently initialized to tell us
372 ;; what the home lambda is.
374 ;; We could get fancy about this, flooding through the
375 ;; graph of all the previous blocks, but in practice it
376 ;; seems to work just to grab the first previous block and
378 (node-home-lambda (block-last (first pred-list)))
379 ;; In case 2, we end up with an empty PRED-LIST and
380 ;; have to punt: There's no home lambda.
383 ;;; Return the non-LET LAMBDA that holds BLOCK's code.
384 (declaim (ftype (sfunction (cblock) clambda) block-home-lambda))
385 (defun block-home-lambda (block)
386 (block-home-lambda-or-null block))
388 ;;; Return the IR1 physical environment for BLOCK.
389 (declaim (ftype (sfunction (cblock) physenv) block-physenv))
390 (defun block-physenv (block)
391 (lambda-physenv (block-home-lambda block)))
393 ;;; Return the Top Level Form number of PATH, i.e. the ordinal number
394 ;;; of its original source's top level form in its compilation unit.
395 (defun source-path-tlf-number (path)
396 (declare (list path))
399 ;;; Return the (reversed) list for the PATH in the original source
400 ;;; (with the Top Level Form number last).
401 (defun source-path-original-source (path)
402 (declare (list path) (inline member))
403 (cddr (member 'original-source-start path :test #'eq)))
405 ;;; Return the Form Number of PATH's original source inside the Top
406 ;;; Level Form that contains it. This is determined by the order that
407 ;;; we walk the subforms of the top level source form.
408 (defun source-path-form-number (path)
409 (declare (list path) (inline member))
410 (cadr (member 'original-source-start path :test #'eq)))
412 ;;; Return a list of all the enclosing forms not in the original
413 ;;; source that converted to get to this form, with the immediate
414 ;;; source for node at the start of the list.
415 (defun source-path-forms (path)
416 (subseq path 0 (position 'original-source-start path)))
418 ;;; Return the innermost source form for NODE.
419 (defun node-source-form (node)
420 (declare (type node node))
421 (let* ((path (node-source-path node))
422 (forms (source-path-forms path)))
425 (values (find-original-source path)))))
427 ;;; Return NODE-SOURCE-FORM, T if lvar has a single use, otherwise
429 (defun lvar-source (lvar)
430 (let ((use (lvar-uses lvar)))
433 (values (node-source-form use) t))))
435 ;;; Return the unique node, delivering a value to LVAR.
436 #!-sb-fluid (declaim (inline lvar-use))
437 (defun lvar-use (lvar)
438 (the (not list) (lvar-uses lvar)))
440 #!-sb-fluid (declaim (inline lvar-has-single-use-p))
441 (defun lvar-has-single-use-p (lvar)
442 (typep (lvar-uses lvar) '(not list)))
444 ;;; Return the LAMBDA that is CTRAN's home, or NIL if there is none.
445 (declaim (ftype (sfunction (ctran) (or clambda null))
446 ctran-home-lambda-or-null))
447 (defun ctran-home-lambda-or-null (ctran)
448 ;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
449 ;; implementation might not be quite right, or might be uglier than
450 ;; necessary. It appears that the original Python never found a need
451 ;; to do this operation. The obvious things based on
452 ;; NODE-HOME-LAMBDA of CTRAN-USE usually work; then if that fails,
453 ;; BLOCK-HOME-LAMBDA of CTRAN-BLOCK works, given that we
454 ;; generalize it enough to grovel harder when the simple CMU CL
455 ;; approach fails, and furthermore realize that in some exceptional
456 ;; cases it might return NIL. -- WHN 2001-12-04
457 (cond ((ctran-use ctran)
458 (node-home-lambda (ctran-use ctran)))
460 (block-home-lambda-or-null (ctran-block ctran)))
462 (bug "confused about home lambda for ~S" ctran))))
464 ;;; Return the LAMBDA that is CTRAN's home.
465 (declaim (ftype (sfunction (ctran) clambda) ctran-home-lambda))
466 (defun ctran-home-lambda (ctran)
467 (ctran-home-lambda-or-null ctran))
469 #!-sb-fluid (declaim (inline lvar-single-value-p))
470 (defun lvar-single-value-p (lvar)
472 (let ((dest (lvar-dest lvar)))
477 (eq (basic-combination-fun dest) lvar))
480 (declare (notinline lvar-single-value-p))
481 (and (not (values-type-p (cast-asserted-type dest)))
482 (lvar-single-value-p (node-lvar dest)))))
486 (defun principal-lvar-end (lvar)
487 (loop for prev = lvar then (node-lvar dest)
488 for dest = (and prev (lvar-dest prev))
490 finally (return (values dest prev))))
492 (defun principal-lvar-single-valuify (lvar)
493 (loop for prev = lvar then (node-lvar dest)
494 for dest = (and prev (lvar-dest prev))
496 do (setf (node-derived-type dest)
497 (make-short-values-type (list (single-value-type
498 (node-derived-type dest)))))
499 (reoptimize-lvar prev)))
501 ;;; Return a new LEXENV just like DEFAULT except for the specified
502 ;;; slot values. Values for the alist slots are NCONCed to the
503 ;;; beginning of the current value, rather than replacing it entirely.
504 (defun make-lexenv (&key (default *lexenv*)
505 funs vars blocks tags
507 (lambda (lexenv-lambda default))
508 (cleanup (lexenv-cleanup default))
509 (policy (lexenv-policy default)))
510 (macrolet ((frob (var slot)
511 `(let ((old (,slot default)))
515 (internal-make-lexenv
516 (frob funs lexenv-funs)
517 (frob vars lexenv-vars)
518 (frob blocks lexenv-blocks)
519 (frob tags lexenv-tags)
520 (frob type-restrictions lexenv-type-restrictions)
521 lambda cleanup policy)))
523 ;;; Makes a LEXENV, suitable for using in a MACROLET introduced
525 (defun make-restricted-lexenv (lexenv)
526 (flet ((fun-good-p (fun)
527 (destructuring-bind (name . thing) fun
528 (declare (ignore name))
532 (cons (aver (eq (car thing) 'macro))
535 (destructuring-bind (name . thing) var
536 (declare (ignore name))
539 (cons (aver (eq (car thing) 'macro))
541 (heap-alien-info nil)))))
542 (internal-make-lexenv
543 (remove-if-not #'fun-good-p (lexenv-funs lexenv))
544 (remove-if-not #'var-good-p (lexenv-vars lexenv))
547 (lexenv-type-restrictions lexenv) ; XXX
550 (lexenv-policy lexenv))))
552 ;;;; flow/DFO/component hackery
554 ;;; Join BLOCK1 and BLOCK2.
555 (defun link-blocks (block1 block2)
556 (declare (type cblock block1 block2))
557 (setf (block-succ block1)
558 (if (block-succ block1)
559 (%link-blocks block1 block2)
561 (push block1 (block-pred block2))
563 (defun %link-blocks (block1 block2)
564 (declare (type cblock block1 block2))
565 (let ((succ1 (block-succ block1)))
566 (aver (not (memq block2 succ1)))
567 (cons block2 succ1)))
569 ;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
570 ;;; this leaves a successor with a single predecessor that ends in an
571 ;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
572 ;;; now be able to be propagated to the successor.
573 (defun unlink-blocks (block1 block2)
574 (declare (type cblock block1 block2))
575 (let ((succ1 (block-succ block1)))
576 (if (eq block2 (car succ1))
577 (setf (block-succ block1) (cdr succ1))
578 (do ((succ (cdr succ1) (cdr succ))
580 ((eq (car succ) block2)
581 (setf (cdr prev) (cdr succ)))
584 (let ((new-pred (delq block1 (block-pred block2))))
585 (setf (block-pred block2) new-pred)
586 (when (singleton-p new-pred)
587 (let ((pred-block (first new-pred)))
588 (when (if-p (block-last pred-block))
589 (setf (block-test-modified pred-block) t)))))
592 ;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
593 ;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
594 ;;; consequent/alternative blocks to point to NEW. We also set
595 ;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
596 ;;; the new successor.
597 (defun change-block-successor (block old new)
598 (declare (type cblock new old block))
599 (unlink-blocks block old)
600 (let ((last (block-last block))
601 (comp (block-component block)))
602 (setf (component-reanalyze comp) t)
605 (setf (block-test-modified block) t)
606 (let* ((succ-left (block-succ block))
607 (new (if (and (eq new (component-tail comp))
611 (unless (memq new succ-left)
612 (link-blocks block new))
613 (macrolet ((frob (slot)
614 `(when (eq (,slot last) old)
615 (setf (,slot last) new))))
617 (frob if-alternative)
618 (when (eq (if-consequent last)
619 (if-alternative last))
620 (setf (component-reoptimize (block-component block)) t)))))
622 (unless (memq new (block-succ block))
623 (link-blocks block new)))))
627 ;;; Unlink a block from the next/prev chain. We also null out the
629 (declaim (ftype (sfunction (cblock) (values)) remove-from-dfo))
630 (defun remove-from-dfo (block)
631 (let ((next (block-next block))
632 (prev (block-prev block)))
633 (setf (block-component block) nil)
634 (setf (block-next prev) next)
635 (setf (block-prev next) prev))
638 ;;; Add BLOCK to the next/prev chain following AFTER. We also set the
639 ;;; COMPONENT to be the same as for AFTER.
640 (defun add-to-dfo (block after)
641 (declare (type cblock block after))
642 (let ((next (block-next after))
643 (comp (block-component after)))
644 (aver (not (eq (component-kind comp) :deleted)))
645 (setf (block-component block) comp)
646 (setf (block-next after) block)
647 (setf (block-prev block) after)
648 (setf (block-next block) next)
649 (setf (block-prev next) block))
652 ;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
653 ;;; the head and tail which are set to T.
654 (declaim (ftype (sfunction (component) (values)) clear-flags))
655 (defun clear-flags (component)
656 (let ((head (component-head component))
657 (tail (component-tail component)))
658 (setf (block-flag head) t)
659 (setf (block-flag tail) t)
660 (do-blocks (block component)
661 (setf (block-flag block) nil)))
664 ;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
665 ;;; true in the head and tail blocks.
666 (declaim (ftype (sfunction () component) make-empty-component))
667 (defun make-empty-component ()
668 (let* ((head (make-block-key :start nil :component nil))
669 (tail (make-block-key :start nil :component nil))
670 (res (make-component head tail)))
671 (setf (block-flag head) t)
672 (setf (block-flag tail) t)
673 (setf (block-component head) res)
674 (setf (block-component tail) res)
675 (setf (block-next head) tail)
676 (setf (block-prev tail) head)
679 ;;; Make NODE the LAST node in its block, splitting the block if necessary.
680 ;;; The new block is added to the DFO immediately following NODE's block.
681 (defun node-ends-block (node)
682 (declare (type node node))
683 (let* ((block (node-block node))
684 (start (node-next node))
685 (last (block-last block)))
686 (unless (eq last node)
687 (aver (and (eq (ctran-kind start) :inside-block)
688 (not (block-delete-p block))))
689 (let* ((succ (block-succ block))
691 (make-block-key :start start
692 :component (block-component block)
693 :succ succ :last last)))
694 (setf (ctran-kind start) :block-start)
695 (setf (ctran-use start) nil)
696 (setf (block-last block) node)
697 (setf (node-next node) nil)
700 (cons new-block (remove block (block-pred b)))))
701 (setf (block-succ block) ())
702 (link-blocks block new-block)
703 (add-to-dfo new-block block)
704 (setf (component-reanalyze (block-component block)) t)
706 (do ((ctran start (node-next (ctran-next ctran))))
708 (setf (ctran-block ctran) new-block))
710 (setf (block-type-asserted block) t)
711 (setf (block-test-modified block) t))))
716 ;;; Deal with deleting the last (read) reference to a LAMBDA-VAR.
717 (defun delete-lambda-var (leaf)
718 (declare (type lambda-var leaf))
720 ;; Iterate over all local calls flushing the corresponding argument,
721 ;; allowing the computation of the argument to be deleted. We also
722 ;; mark the LET for reoptimization, since it may be that we have
723 ;; deleted its last variable.
724 (let* ((fun (lambda-var-home leaf))
725 (n (position leaf (lambda-vars fun))))
726 (dolist (ref (leaf-refs fun))
727 (let* ((lvar (node-lvar ref))
728 (dest (and lvar (lvar-dest lvar))))
729 (when (and (combination-p dest)
730 (eq (basic-combination-fun dest) lvar)
731 (eq (basic-combination-kind dest) :local))
732 (let* ((args (basic-combination-args dest))
734 (reoptimize-lvar arg)
736 (setf (elt args n) nil))))))
738 ;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
739 ;; too much difficulty, since we can efficiently implement
740 ;; write-only variables. We iterate over the SETs, marking their
741 ;; blocks for dead code flushing, since we can delete SETs whose
743 (dolist (set (lambda-var-sets leaf))
744 (setf (block-flush-p (node-block set)) t))
748 ;;; Note that something interesting has happened to VAR.
749 (defun reoptimize-lambda-var (var)
750 (declare (type lambda-var var))
751 (let ((fun (lambda-var-home var)))
752 ;; We only deal with LET variables, marking the corresponding
753 ;; initial value arg as needing to be reoptimized.
754 (when (and (eq (functional-kind fun) :let)
756 (do ((args (basic-combination-args
757 (lvar-dest (node-lvar (first (leaf-refs fun)))))
759 (vars (lambda-vars fun) (cdr vars)))
761 (reoptimize-lvar (car args))))))
764 ;;; Delete a function that has no references. This need only be called
765 ;;; on functions that never had any references, since otherwise
766 ;;; DELETE-REF will handle the deletion.
767 (defun delete-functional (fun)
768 (aver (and (null (leaf-refs fun))
769 (not (functional-entry-fun fun))))
771 (optional-dispatch (delete-optional-dispatch fun))
772 (clambda (delete-lambda fun)))
775 ;;; Deal with deleting the last reference to a CLAMBDA. It is called
776 ;;; in two situations: when the lambda is unreachable (so that its
777 ;;; body mey be deleted), and when it is an effectless LET (in this
778 ;;; case its body is reachable and is not completely "its"). We set
779 ;;; FUNCTIONAL-KIND to :DELETED and rely on IR1-OPTIMIZE to delete its
781 (defun delete-lambda (clambda)
782 (declare (type clambda clambda))
783 (let ((original-kind (functional-kind clambda))
784 (bind (lambda-bind clambda)))
785 (aver (not (member original-kind '(:deleted :optional :toplevel))))
786 (aver (not (functional-has-external-references-p clambda)))
787 (setf (functional-kind clambda) :deleted)
788 (setf (lambda-bind clambda) nil)
790 (when bind ; CLAMBDA is deleted due to unreachability
791 (labels ((delete-children (lambda)
792 (dolist (child (lambda-children lambda))
793 (if (eq (functional-kind child) :deleted)
794 (delete-children child)
795 (delete-lambda child)))
796 (setf (lambda-children lambda) nil)
797 (setf (lambda-parent lambda) nil)))
798 (delete-children clambda)))
799 (dolist (let (lambda-lets clambda))
800 (setf (lambda-bind let) nil)
801 (setf (functional-kind let) :deleted))
803 ;; LET may be deleted if its BIND is unreachable. Autonomous
804 ;; function may be deleted if it has no reachable references.
805 (unless (member original-kind '(:let :mv-let :assignment))
806 (dolist (ref (lambda-refs clambda))
807 (mark-for-deletion (node-block ref))))
809 ;; (The IF test is (FUNCTIONAL-SOMEWHAT-LETLIKE-P CLAMBDA), except
810 ;; that we're using the old value of the KIND slot, not the
811 ;; current slot value, which has now been set to :DELETED.)
812 (if (member original-kind '(:let :mv-let :assignment))
813 (let ((home (lambda-home clambda)))
814 (setf (lambda-lets home) (delete clambda (lambda-lets home))))
815 ;; If the function isn't a LET, we unlink the function head
816 ;; and tail from the component head and tail to indicate that
817 ;; the code is unreachable. We also delete the function from
818 ;; COMPONENT-LAMBDAS (it won't be there before local call
819 ;; analysis, but no matter.) If the lambda was never
820 ;; referenced, we give a note.
821 (let* ((bind-block (node-block bind))
822 (component (block-component bind-block))
823 (return (lambda-return clambda))
824 (return-block (and return (node-block return))))
825 (unless (leaf-ever-used clambda)
826 (let ((*compiler-error-context* bind))
827 (compiler-notify 'code-deletion-note
828 :format-control "deleting unused function~:[.~;~:*~% ~S~]"
829 :format-arguments (list (leaf-debug-name clambda)))))
830 (unless (block-delete-p bind-block)
831 (unlink-blocks (component-head component) bind-block))
832 (when (and return-block (not (block-delete-p return-block)))
833 (mark-for-deletion return-block)
834 (unlink-blocks return-block (component-tail component)))
835 (setf (component-reanalyze component) t)
836 (let ((tails (lambda-tail-set clambda)))
837 (setf (tail-set-funs tails)
838 (delete clambda (tail-set-funs tails)))
839 (setf (lambda-tail-set clambda) nil))
840 (setf (component-lambdas component)
841 (delq clambda (component-lambdas component)))))
843 ;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
844 ;; ENTRY-FUN so that people will know that it is not an entry
846 (when (eq original-kind :external)
847 (let ((fun (functional-entry-fun clambda)))
848 (setf (functional-entry-fun fun) nil)
849 (when (optional-dispatch-p fun)
850 (delete-optional-dispatch fun)))))
854 ;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
855 ;;; have to be a bit more careful than with lambdas, since DELETE-REF
856 ;;; is used both before and after local call analysis. Afterward, all
857 ;;; references to still-existing OPTIONAL-DISPATCHes have been moved
858 ;;; to the XEP, leaving it with no references at all. So we look at
859 ;;; the XEP to see whether an optional-dispatch is still really being
860 ;;; used. But before local call analysis, there are no XEPs, and all
861 ;;; references are direct.
863 ;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
864 ;;; entry-points, making them be normal lambdas, and then deleting the
865 ;;; ones with no references. This deletes any e-p lambdas that were
866 ;;; either never referenced, or couldn't be deleted when the last
867 ;;; reference was deleted (due to their :OPTIONAL kind.)
869 ;;; Note that the last optional entry point may alias the main entry,
870 ;;; so when we process the main entry, its KIND may have been changed
871 ;;; to NIL or even converted to a LETlike value.
872 (defun delete-optional-dispatch (leaf)
873 (declare (type optional-dispatch leaf))
874 (let ((entry (functional-entry-fun leaf)))
875 (unless (and entry (leaf-refs entry))
876 (aver (or (not entry) (eq (functional-kind entry) :deleted)))
877 (setf (functional-kind leaf) :deleted)
880 (unless (eq (functional-kind fun) :deleted)
881 (aver (eq (functional-kind fun) :optional))
882 (setf (functional-kind fun) nil)
883 (let ((refs (leaf-refs fun)))
887 (or (maybe-let-convert fun)
888 (maybe-convert-to-assignment fun)))
890 (maybe-convert-to-assignment fun)))))))
892 (dolist (ep (optional-dispatch-entry-points leaf))
893 (when (promise-ready-p ep)
895 (when (optional-dispatch-more-entry leaf)
896 (frob (optional-dispatch-more-entry leaf)))
897 (let ((main (optional-dispatch-main-entry leaf)))
898 (when (eq (functional-kind main) :optional)
903 ;;; Do stuff to delete the semantic attachments of a REF node. When
904 ;;; this leaves zero or one reference, we do a type dispatch off of
905 ;;; the leaf to determine if a special action is appropriate.
906 (defun delete-ref (ref)
907 (declare (type ref ref))
908 (let* ((leaf (ref-leaf ref))
909 (refs (delq ref (leaf-refs leaf))))
910 (setf (leaf-refs leaf) refs)
915 (delete-lambda-var leaf))
917 (ecase (functional-kind leaf)
918 ((nil :let :mv-let :assignment :escape :cleanup)
919 (aver (null (functional-entry-fun leaf)))
920 (delete-lambda leaf))
922 (delete-lambda leaf))
923 ((:deleted :optional))))
925 (unless (eq (functional-kind leaf) :deleted)
926 (delete-optional-dispatch leaf)))))
929 (clambda (or (maybe-let-convert leaf)
930 (maybe-convert-to-assignment leaf)))
931 (lambda-var (reoptimize-lambda-var leaf))))
934 (clambda (maybe-convert-to-assignment leaf))))))
938 ;;; This function is called by people who delete nodes; it provides a
939 ;;; way to indicate that the value of a lvar is no longer used. We
940 ;;; null out the LVAR-DEST, set FLUSH-P in the blocks containing uses
941 ;;; of LVAR and set COMPONENT-REOPTIMIZE.
942 (defun flush-dest (lvar)
943 (declare (type (or lvar null) lvar))
945 (setf (lvar-dest lvar) nil)
946 (flush-lvar-externally-checkable-type lvar)
948 (let ((prev (node-prev use)))
949 (let ((block (ctran-block prev)))
950 (setf (component-reoptimize (block-component block)) t)
951 (setf (block-attributep (block-flags block) flush-p type-asserted)
953 (setf (node-lvar use) nil))
954 (setf (lvar-uses lvar) nil))
957 (defun delete-dest (lvar)
959 (let* ((dest (lvar-dest lvar))
960 (prev (node-prev dest)))
961 (let ((block (ctran-block prev)))
962 (unless (block-delete-p block)
963 (mark-for-deletion block))))))
965 ;;; Do a graph walk backward from BLOCK, marking all predecessor
966 ;;; blocks with the DELETE-P flag.
967 (defun mark-for-deletion (block)
968 (declare (type cblock block))
969 (let* ((component (block-component block))
970 (head (component-head component)))
971 (labels ((helper (block)
972 (setf (block-delete-p block) t)
973 (dolist (pred (block-pred block))
974 (unless (or (block-delete-p pred)
977 (unless (block-delete-p block)
979 (setf (component-reanalyze component) t))))
982 ;;; This function does what is necessary to eliminate the code in it
983 ;;; from the IR1 representation. This involves unlinking it from its
984 ;;; predecessors and successors and deleting various node-specific
985 ;;; semantic information.
986 (defun delete-block (block &optional silent)
987 (declare (type cblock block))
988 (aver (block-component block)) ; else block is already deleted!
990 (note-block-deletion block))
991 (setf (block-delete-p block) t)
993 (dolist (b (block-pred block))
994 (unlink-blocks b block)
995 ;; In bug 147 the almost-all-blocks-have-a-successor invariant was
996 ;; broken when successors were deleted without setting the
997 ;; BLOCK-DELETE-P flags of their predececessors. Make sure that
998 ;; doesn't happen again.
999 (aver (not (and (null (block-succ b))
1000 (not (block-delete-p b))
1001 (not (eq b (component-head (block-component b))))))))
1002 (dolist (b (block-succ block))
1003 (unlink-blocks block b))
1005 (do-nodes-carefully (node block)
1006 (when (valued-node-p node)
1007 (delete-lvar-use node))
1009 (ref (delete-ref node))
1010 (cif (flush-dest (if-test node)))
1011 ;; The next two cases serve to maintain the invariant that a LET
1012 ;; always has a well-formed COMBINATION, REF and BIND. We delete
1013 ;; the lambda whenever we delete any of these, but we must be
1014 ;; careful that this LET has not already been partially deleted.
1016 (when (and (eq (basic-combination-kind node) :local)
1017 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
1018 (lvar-uses (basic-combination-fun node)))
1019 (let ((fun (combination-lambda node)))
1020 ;; If our REF was the second-to-last ref, and has been
1021 ;; deleted, then FUN may be a LET for some other
1023 (when (and (functional-letlike-p fun)
1024 (eq (let-combination fun) node))
1025 (delete-lambda fun))))
1026 (flush-dest (basic-combination-fun node))
1027 (dolist (arg (basic-combination-args node))
1028 (when arg (flush-dest arg))))
1030 (let ((lambda (bind-lambda node)))
1031 (unless (eq (functional-kind lambda) :deleted)
1032 (delete-lambda lambda))))
1034 (let ((value (exit-value node))
1035 (entry (exit-entry node)))
1039 (setf (entry-exits entry)
1040 (delq node (entry-exits entry))))))
1042 (flush-dest (return-result node))
1043 (delete-return node))
1045 (flush-dest (set-value node))
1046 (let ((var (set-var node)))
1047 (setf (basic-var-sets var)
1048 (delete node (basic-var-sets var)))))
1050 (flush-dest (cast-value node)))))
1052 (remove-from-dfo block)
1055 ;;; Do stuff to indicate that the return node NODE is being deleted.
1056 (defun delete-return (node)
1057 (declare (type creturn node))
1058 (let* ((fun (return-lambda node))
1059 (tail-set (lambda-tail-set fun)))
1060 (aver (lambda-return fun))
1061 (setf (lambda-return fun) nil)
1062 (when (and tail-set (not (find-if #'lambda-return
1063 (tail-set-funs tail-set))))
1064 (setf (tail-set-type tail-set) *empty-type*)))
1067 ;;; If any of the VARS in FUN was never referenced and was not
1068 ;;; declared IGNORE, then complain.
1069 (defun note-unreferenced-vars (fun)
1070 (declare (type clambda fun))
1071 (dolist (var (lambda-vars fun))
1072 (unless (or (leaf-ever-used var)
1073 (lambda-var-ignorep var))
1074 (let ((*compiler-error-context* (lambda-bind fun)))
1075 (unless (policy *compiler-error-context* (= inhibit-warnings 3))
1076 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
1077 ;; requires this to be no more than a STYLE-WARNING.
1078 (compiler-style-warn "The variable ~S is defined but never used."
1079 (leaf-debug-name var)))
1080 (setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
1083 (defvar *deletion-ignored-objects* '(t nil))
1085 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
1086 ;;; our recursion so that we don't get lost in circular structures. We
1087 ;;; ignore the car of forms if they are a symbol (to prevent confusing
1088 ;;; function referencess with variables), and we also ignore anything
1090 (defun present-in-form (obj form depth)
1091 (declare (type (integer 0 20) depth))
1092 (cond ((= depth 20) nil)
1096 (let ((first (car form))
1098 (if (member first '(quote function))
1100 (or (and (not (symbolp first))
1101 (present-in-form obj first depth))
1102 (do ((l (cdr form) (cdr l))
1104 ((or (atom l) (> n 100))
1106 (declare (fixnum n))
1107 (when (present-in-form obj (car l) depth)
1110 ;;; This function is called on a block immediately before we delete
1111 ;;; it. We check to see whether any of the code about to die appeared
1112 ;;; in the original source, and emit a note if so.
1114 ;;; If the block was in a lambda is now deleted, then we ignore the
1115 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
1116 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
1117 ;;; reasonable for a function to not return, and there is a different
1118 ;;; note for that case anyway.
1120 ;;; If the actual source is an atom, then we use a bunch of heuristics
1121 ;;; to guess whether this reference really appeared in the original
1123 ;;; -- If a symbol, it must be interned and not a keyword.
1124 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
1125 ;;; or a character.)
1126 ;;; -- The atom must be "present" in the original source form, and
1127 ;;; present in all intervening actual source forms.
1128 (defun note-block-deletion (block)
1129 (let ((home (block-home-lambda block)))
1130 (unless (eq (functional-kind home) :deleted)
1131 (do-nodes (node nil block)
1132 (let* ((path (node-source-path node))
1133 (first (first path)))
1134 (when (or (eq first 'original-source-start)
1136 (or (not (symbolp first))
1137 (let ((pkg (symbol-package first)))
1139 (not (eq pkg (symbol-package :end))))))
1140 (not (member first *deletion-ignored-objects*))
1141 (not (typep first '(or fixnum character)))
1143 (present-in-form first x 0))
1144 (source-path-forms path))
1145 (present-in-form first (find-original-source path)
1147 (unless (return-p node)
1148 (let ((*compiler-error-context* node))
1149 (compiler-notify 'code-deletion-note
1150 :format-control "deleting unreachable code"
1151 :format-arguments nil)))
1155 ;;; Delete a node from a block, deleting the block if there are no
1156 ;;; nodes left. We remove the node from the uses of its LVAR.
1158 ;;; If the node is the last node, there must be exactly one successor.
1159 ;;; We link all of our precedessors to the successor and unlink the
1160 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1161 ;;; left, and the block is a successor of itself, then we replace the
1162 ;;; only node with a degenerate exit node. This provides a way to
1163 ;;; represent the bodyless infinite loop, given the prohibition on
1164 ;;; empty blocks in IR1.
1165 (defun unlink-node (node)
1166 (declare (type node node))
1167 (when (valued-node-p node)
1168 (delete-lvar-use node))
1170 (let* ((ctran (node-next node))
1171 (next (and ctran (ctran-next ctran)))
1172 (prev (node-prev node))
1173 (block (ctran-block prev))
1174 (prev-kind (ctran-kind prev))
1175 (last (block-last block)))
1177 (setf (block-type-asserted block) t)
1178 (setf (block-test-modified block) t)
1180 (cond ((or (eq prev-kind :inside-block)
1181 (and (eq prev-kind :block-start)
1182 (not (eq node last))))
1183 (cond ((eq node last)
1184 (setf (block-last block) (ctran-use prev))
1185 (setf (node-next (ctran-use prev)) nil))
1187 (setf (ctran-next prev) next)
1188 (setf (node-prev next) prev)
1189 (when (if-p next) ; AOP wanted
1190 (reoptimize-lvar (if-test next)))))
1191 (setf (node-prev node) nil)
1194 (aver (eq prev-kind :block-start))
1195 (aver (eq node last))
1196 (let* ((succ (block-succ block))
1197 (next (first succ)))
1198 (aver (singleton-p succ))
1200 ((eq block (first succ))
1201 (with-ir1-environment-from-node node
1202 (let ((exit (make-exit)))
1203 (setf (ctran-next prev) nil)
1204 (link-node-to-previous-ctran exit prev)
1205 (setf (block-last block) exit)))
1206 (setf (node-prev node) nil)
1209 (aver (eq (block-start-cleanup block)
1210 (block-end-cleanup block)))
1211 (unlink-blocks block next)
1212 (dolist (pred (block-pred block))
1213 (change-block-successor pred block next))
1214 (remove-from-dfo block)
1215 (setf (block-delete-p block) t)
1216 (setf (node-prev node) nil)
1219 ;;; Return true if NODE has been deleted, false if it is still a valid
1221 (defun node-deleted (node)
1222 (declare (type node node))
1223 (let ((prev (node-prev node)))
1225 (let ((block (ctran-block prev)))
1226 (and (block-component block)
1227 (not (block-delete-p block))))))))
1229 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1230 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1231 ;;; triggered by deletion.
1232 (defun delete-component (component)
1233 (declare (type component component))
1234 (aver (null (component-new-functionals component)))
1235 (setf (component-kind component) :deleted)
1236 (do-blocks (block component)
1237 (setf (block-delete-p block) t))
1238 (dolist (fun (component-lambdas component))
1239 (unless (eq (functional-kind fun) :deleted)
1240 (setf (functional-kind fun) nil)
1241 (setf (functional-entry-fun fun) nil)
1242 (setf (leaf-refs fun) nil)
1243 (delete-functional fun)))
1244 (do-blocks (block component)
1245 (delete-block block))
1248 ;;; Convert code of the form
1249 ;;; (FOO ... (FUN ...) ...)
1251 ;;; (FOO ... ... ...).
1252 ;;; In other words, replace the function combination FUN by its
1253 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1254 ;;; to blow out of whatever transform called this. Note, as the number
1255 ;;; of arguments changes, the transform must be prepared to return a
1256 ;;; lambda with a new lambda-list with the correct number of
1258 (defun extract-fun-args (lvar fun num-args)
1260 "If LVAR is a call to FUN with NUM-ARGS args, change those arguments
1261 to feed directly to the LVAR-DEST of LVAR, which must be a
1263 (declare (type lvar lvar)
1265 (type index num-args))
1266 (let ((outside (lvar-dest lvar))
1267 (inside (lvar-uses lvar)))
1268 (aver (combination-p outside))
1269 (unless (combination-p inside)
1270 (give-up-ir1-transform))
1271 (let ((inside-fun (combination-fun inside)))
1272 (unless (eq (lvar-fun-name inside-fun) fun)
1273 (give-up-ir1-transform))
1274 (let ((inside-args (combination-args inside)))
1275 (unless (= (length inside-args) num-args)
1276 (give-up-ir1-transform))
1277 (let* ((outside-args (combination-args outside))
1278 (arg-position (position lvar outside-args))
1279 (before-args (subseq outside-args 0 arg-position))
1280 (after-args (subseq outside-args (1+ arg-position))))
1281 (dolist (arg inside-args)
1282 (setf (lvar-dest arg) outside)
1283 (flush-lvar-externally-checkable-type arg))
1284 (setf (combination-args inside) nil)
1285 (setf (combination-args outside)
1286 (append before-args inside-args after-args))
1287 (change-ref-leaf (lvar-uses inside-fun)
1288 (find-free-fun 'list "???"))
1289 (setf (combination-kind inside)
1290 (info :function :info 'list))
1291 (setf (node-derived-type inside) *wild-type*)
1295 (defun flush-combination (combination)
1296 (declare (type combination combination))
1297 (flush-dest (combination-fun combination))
1298 (dolist (arg (combination-args combination))
1300 (unlink-node combination)
1306 ;;; Change the LEAF that a REF refers to.
1307 (defun change-ref-leaf (ref leaf)
1308 (declare (type ref ref) (type leaf leaf))
1309 (unless (eq (ref-leaf ref) leaf)
1310 (push ref (leaf-refs leaf))
1312 (setf (ref-leaf ref) leaf)
1313 (setf (leaf-ever-used leaf) t)
1314 (let* ((ltype (leaf-type leaf))
1315 (vltype (make-single-value-type ltype)))
1316 (if (let* ((lvar (node-lvar ref))
1317 (dest (and lvar (lvar-dest lvar))))
1318 (and (basic-combination-p dest)
1319 (eq lvar (basic-combination-fun dest))
1320 (csubtypep ltype (specifier-type 'function))))
1321 (setf (node-derived-type ref) vltype)
1322 (derive-node-type ref vltype)))
1323 (reoptimize-lvar (node-lvar ref)))
1326 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1327 (defun substitute-leaf (new-leaf old-leaf)
1328 (declare (type leaf new-leaf old-leaf))
1329 (dolist (ref (leaf-refs old-leaf))
1330 (change-ref-leaf ref new-leaf))
1333 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1334 ;;; whether to substitute
1335 (defun substitute-leaf-if (test new-leaf old-leaf)
1336 (declare (type leaf new-leaf old-leaf) (type function test))
1337 (dolist (ref (leaf-refs old-leaf))
1338 (when (funcall test ref)
1339 (change-ref-leaf ref new-leaf)))
1342 ;;; Return a LEAF which represents the specified constant object. If
1343 ;;; the object is not in *CONSTANTS*, then we create a new constant
1344 ;;; LEAF and enter it.
1345 (defun find-constant (object)
1347 ;; FIXME: What is the significance of this test? ("things
1348 ;; that are worth uniquifying"?)
1349 '(or symbol number character instance))
1350 (or (gethash object *constants*)
1351 (setf (gethash object *constants*)
1352 (make-constant :value object
1353 :%source-name '.anonymous.
1354 :type (ctype-of object)
1355 :where-from :defined)))
1356 (make-constant :value object
1357 :%source-name '.anonymous.
1358 :type (ctype-of object)
1359 :where-from :defined)))
1361 ;;; Return true if VAR would have to be closed over if environment
1362 ;;; analysis ran now (i.e. if there are any uses that have a different
1363 ;;; home lambda than VAR's home.)
1364 (defun closure-var-p (var)
1365 (declare (type lambda-var var))
1366 (let ((home (lambda-var-home var)))
1367 (cond ((eq (functional-kind home) :deleted)
1369 (t (let ((home (lambda-home home)))
1372 :key #'node-home-lambda
1374 (or (frob (leaf-refs var))
1375 (frob (basic-var-sets var)))))))))
1377 ;;; If there is a non-local exit noted in ENTRY's environment that
1378 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1379 (defun find-nlx-info (exit)
1380 (declare (type exit exit))
1381 (let* ((entry (exit-entry exit))
1382 (entry-cleanup (entry-cleanup entry)))
1383 (dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
1384 (when (eq (nlx-info-exit nlx) exit)
1387 ;;;; functional hackery
1389 (declaim (ftype (sfunction (functional) clambda) main-entry))
1390 (defun main-entry (functional)
1391 (etypecase functional
1392 (clambda functional)
1394 (optional-dispatch-main-entry functional))))
1396 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1397 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1398 ;;; optional with null default and no SUPPLIED-P. There must be a
1399 ;;; &REST arg with no references.
1400 (declaim (ftype (sfunction (functional) boolean) looks-like-an-mv-bind))
1401 (defun looks-like-an-mv-bind (functional)
1402 (and (optional-dispatch-p functional)
1403 (do ((arg (optional-dispatch-arglist functional) (cdr arg)))
1405 (let ((info (lambda-var-arg-info (car arg))))
1406 (unless info (return nil))
1407 (case (arg-info-kind info)
1409 (when (or (arg-info-supplied-p info) (arg-info-default info))
1412 (return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
1416 ;;; Return true if function is an external entry point. This is true
1417 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1418 ;;; (:TOPLEVEL kind.)
1420 (declare (type functional fun))
1421 (not (null (member (functional-kind fun) '(:external :toplevel)))))
1423 ;;; If LVAR's only use is a non-notinline global function reference,
1424 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1425 ;;; is true, then we don't care if the leaf is NOTINLINE.
1426 (defun lvar-fun-name (lvar &optional notinline-ok)
1427 (declare (type lvar lvar))
1428 (let ((use (lvar-uses lvar)))
1430 (let ((leaf (ref-leaf use)))
1431 (if (and (global-var-p leaf)
1432 (eq (global-var-kind leaf) :global-function)
1433 (or (not (defined-fun-p leaf))
1434 (not (eq (defined-fun-inlinep leaf) :notinline))
1436 (leaf-source-name leaf)
1440 ;;; Return the source name of a combination. (This is an idiom
1441 ;;; which was used in CMU CL. I gather it always works. -- WHN)
1442 (defun combination-fun-source-name (combination)
1443 (let ((ref (lvar-uses (combination-fun combination))))
1444 (leaf-source-name (ref-leaf ref))))
1446 ;;; Return the COMBINATION node that is the call to the LET FUN.
1447 (defun let-combination (fun)
1448 (declare (type clambda fun))
1449 (aver (functional-letlike-p fun))
1450 (lvar-dest (node-lvar (first (leaf-refs fun)))))
1452 ;;; Return the initial value lvar for a LET variable, or NIL if there
1454 (defun let-var-initial-value (var)
1455 (declare (type lambda-var var))
1456 (let ((fun (lambda-var-home var)))
1457 (elt (combination-args (let-combination fun))
1458 (position-or-lose var (lambda-vars fun)))))
1460 ;;; Return the LAMBDA that is called by the local CALL.
1461 (defun combination-lambda (call)
1462 (declare (type basic-combination call))
1463 (aver (eq (basic-combination-kind call) :local))
1464 (ref-leaf (lvar-uses (basic-combination-fun call))))
1466 (defvar *inline-expansion-limit* 200
1468 "an upper limit on the number of inline function calls that will be expanded
1469 in any given code object (single function or block compilation)")
1471 ;;; Check whether NODE's component has exceeded its inline expansion
1472 ;;; limit, and warn if so, returning NIL.
1473 (defun inline-expansion-ok (node)
1474 (let ((expanded (incf (component-inline-expansions
1476 (node-block node))))))
1477 (cond ((> expanded *inline-expansion-limit*) nil)
1478 ((= expanded *inline-expansion-limit*)
1479 ;; FIXME: If the objective is to stop the recursive
1480 ;; expansion of inline functions, wouldn't it be more
1481 ;; correct to look back through surrounding expansions
1482 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1483 ;; possibly stored elsewhere too) and suppress expansion
1484 ;; and print this warning when the function being proposed
1485 ;; for inline expansion is found there? (I don't like the
1486 ;; arbitrary numerical limit in principle, and I think
1487 ;; it'll be a nuisance in practice if we ever want the
1488 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1489 ;; arbitrarily huge blocks of code. -- WHN)
1490 (let ((*compiler-error-context* node))
1491 (compiler-notify "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1492 probably trying to~% ~
1493 inline a recursive function."
1494 *inline-expansion-limit*))
1498 ;;; Make sure that FUNCTIONAL is not let-converted or deleted.
1499 (defun assure-functional-live-p (functional)
1500 (declare (type functional functional))
1502 ;; looks LET-converted
1503 (functional-somewhat-letlike-p functional)
1504 ;; It's possible for a LET-converted function to end up
1505 ;; deleted later. In that case, for the purposes of this
1506 ;; analysis, it is LET-converted: LET-converted functionals
1507 ;; are too badly trashed to expand them inline, and deleted
1508 ;; LET-converted functionals are even worse.
1509 (eql (functional-kind functional) :deleted)))
1510 (throw 'locall-already-let-converted functional)))
1514 ;;; Apply a function to some arguments, returning a list of the values
1515 ;;; resulting of the evaluation. If an error is signalled during the
1516 ;;; application, then we produce a warning message using WARN-FUN and
1517 ;;; return NIL as our second value to indicate this. NODE is used as
1518 ;;; the error context for any error message, and CONTEXT is a string
1519 ;;; that is spliced into the warning.
1520 (declaim (ftype (sfunction ((or symbol function) list node function string)
1521 (values list boolean))
1523 (defun careful-call (function args node warn-fun context)
1525 (multiple-value-list
1526 (handler-case (apply function args)
1528 (let ((*compiler-error-context* node))
1529 (funcall warn-fun "Lisp error during ~A:~%~A" context condition)
1530 (return-from careful-call (values nil nil))))))
1533 ;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
1536 ((deffrob (basic careful compiler transform)
1538 (defun ,careful (specifier)
1539 (handler-case (,basic specifier)
1540 (sb!kernel::arg-count-error (condition)
1541 (values nil (list (format nil "~A" condition))))
1542 (simple-error (condition)
1543 (values nil (list* (simple-condition-format-control condition)
1544 (simple-condition-format-arguments condition))))))
1545 (defun ,compiler (specifier)
1546 (multiple-value-bind (type error-args) (,careful specifier)
1548 (apply #'compiler-error error-args))))
1549 (defun ,transform (specifier)
1550 (multiple-value-bind (type error-args) (,careful specifier)
1552 (apply #'give-up-ir1-transform
1554 (deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type)
1555 (deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type))
1558 ;;;; utilities used at run-time for parsing &KEY args in IR1
1560 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1561 ;;; the lvar for the value of the &KEY argument KEY in the list of
1562 ;;; lvars ARGS. It returns the lvar if the keyword is present, or NIL
1563 ;;; otherwise. The legality and constantness of the keywords should
1564 ;;; already have been checked.
1565 (declaim (ftype (sfunction (list keyword) (or lvar null))
1567 (defun find-keyword-lvar (args key)
1568 (do ((arg args (cddr arg)))
1570 (when (eq (lvar-value (first arg)) key)
1571 (return (second arg)))))
1573 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1574 ;;; verify that alternating lvars in ARGS are constant and that there
1575 ;;; is an even number of args.
1576 (declaim (ftype (sfunction (list) boolean) check-key-args-constant))
1577 (defun check-key-args-constant (args)
1578 (do ((arg args (cddr arg)))
1580 (unless (and (rest arg)
1581 (constant-lvar-p (first arg)))
1584 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1585 ;;; verify that the list of lvars ARGS is a well-formed &KEY arglist
1586 ;;; and that only keywords present in the list KEYS are supplied.
1587 (declaim (ftype (sfunction (list list) boolean) check-transform-keys))
1588 (defun check-transform-keys (args keys)
1589 (and (check-key-args-constant args)
1590 (do ((arg args (cddr arg)))
1592 (unless (member (lvar-value (first arg)) keys)
1597 ;;; Called by the expansion of the EVENT macro.
1598 (declaim (ftype (sfunction (event-info (or node null)) *) %event))
1599 (defun %event (info node)
1600 (incf (event-info-count info))
1601 (when (and (>= (event-info-level info) *event-note-threshold*)
1602 (policy (or node *lexenv*)
1603 (= inhibit-warnings 0)))
1604 (let ((*compiler-error-context* node))
1605 (compiler-notify (event-info-description info))))
1607 (let ((action (event-info-action info)))
1608 (when action (funcall action node))))
1611 (defun make-cast (value type policy)
1612 (declare (type lvar value)
1614 (type policy policy))
1615 (%make-cast :asserted-type type
1616 :type-to-check (maybe-weaken-check type policy)
1618 :derived-type (coerce-to-values type)))
1620 (defun cast-type-check (cast)
1621 (declare (type cast cast))
1622 (when (cast-reoptimize cast)
1623 (ir1-optimize-cast cast t))
1624 (cast-%type-check cast))
1626 (defun note-single-valuified-lvar (lvar)
1627 (declare (type (or lvar null) lvar))
1629 (let ((use (lvar-uses lvar)))
1631 (let ((leaf (ref-leaf use)))
1632 (when (and (lambda-var-p leaf)
1633 (null (rest (leaf-refs leaf))))
1634 (reoptimize-lambda-var leaf))))
1635 ((or (listp use) (combination-p use))
1636 (do-uses (node lvar)
1637 (setf (node-reoptimize node) t)
1638 (setf (block-reoptimize (node-block node)) t)
1639 (setf (component-reoptimize (node-component node)) t)))))))