1 ;;;; This file contains miscellaneous utilities used for manipulating
2 ;;;; the IR1 representation.
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
17 ;;; Return the innermost cleanup enclosing NODE, or NIL if there is
18 ;;; none in its function. If NODE has no cleanup, but is in a LET,
19 ;;; then we must still check the environment that the call is in.
20 (defun node-enclosing-cleanup (node)
21 (declare (type node node))
22 (do ((lexenv (node-lexenv node)
23 (lambda-call-lexenv (lexenv-lambda lexenv))))
25 (let ((cup (lexenv-cleanup lexenv)))
26 (when cup (return cup)))))
28 ;;; Convert the FORM in a block inserted between BLOCK1 and BLOCK2 as
29 ;;; an implicit MV-PROG1. The inserted block is returned. NODE is used
30 ;;; for IR1 context when converting the form. Note that the block is
31 ;;; not assigned a number, and is linked into the DFO at the
32 ;;; beginning. We indicate that we have trashed the DFO by setting
33 ;;; COMPONENT-REANALYZE. If CLEANUP is supplied, then convert with
35 (defun insert-cleanup-code (block1 block2 node form &optional cleanup)
36 (declare (type cblock block1 block2) (type node node)
37 (type (or cleanup null) cleanup))
38 (setf (component-reanalyze (block-component block1)) t)
39 (with-ir1-environment-from-node node
40 (with-component-last-block (*current-component*
41 (block-next (component-head *current-component*)))
42 (let* ((start (make-ctran))
43 (block (ctran-starts-block start))
46 (make-lexenv :cleanup cleanup)
48 (change-block-successor block1 block2 block)
49 (link-blocks block block2)
50 (ir1-convert start next nil form)
51 (setf (block-last block) (ctran-use next))
52 (setf (node-next (block-last block)) nil)
57 ;;; Return a list of all the nodes which use LVAR.
58 (declaim (ftype (sfunction (lvar) list) find-uses))
59 (defun find-uses (lvar)
60 (let ((uses (lvar-uses lvar)))
65 (defun principal-lvar-use (lvar)
66 (let ((use (lvar-uses lvar)))
68 (principal-lvar-use (cast-value use))
71 ;;; Update lvar use information so that NODE is no longer a use of its
74 ;;; Note: if you call this function, you may have to do a
75 ;;; REOPTIMIZE-LVAR to inform IR1 optimization that something has
77 (declaim (ftype (sfunction (node) (values))
80 ;;; Just delete NODE from its LVAR uses; LVAR is preserved so it may
81 ;;; be given a new use.
82 (defun %delete-lvar-use (node)
83 (let ((lvar (node-lvar node)))
85 (if (listp (lvar-uses lvar))
86 (let ((new-uses (delq node (lvar-uses lvar))))
87 (setf (lvar-uses lvar)
88 (if (singleton-p new-uses)
91 (setf (lvar-uses lvar) nil))
92 (setf (node-lvar node) nil)))
94 ;;; Delete NODE from its LVAR uses; if LVAR has no other uses, delete
95 ;;; its DEST's block, which must be unreachable.
96 (defun delete-lvar-use (node)
97 (let ((lvar (node-lvar node)))
99 (%delete-lvar-use node)
100 (if (null (lvar-uses lvar))
101 (binding* ((dest (lvar-dest lvar) :exit-if-null)
102 (() (not (node-deleted dest)) :exit-if-null)
103 (block (node-block dest)))
104 (mark-for-deletion block))
105 (reoptimize-lvar lvar))))
108 ;;; Update lvar use information so that NODE uses LVAR.
110 ;;; Note: if you call this function, you may have to do a
111 ;;; REOPTIMIZE-LVAR to inform IR1 optimization that something has
113 (declaim (ftype (sfunction (node (or lvar null)) (values)) add-lvar-use))
114 (defun add-lvar-use (node lvar)
115 (aver (not (node-lvar node)))
117 (let ((uses (lvar-uses lvar)))
118 (setf (lvar-uses lvar)
125 (setf (node-lvar node) lvar)))
129 ;;; Return true if LVAR destination is executed immediately after
130 ;;; NODE. Cleanups are ignored.
131 (defun immediately-used-p (lvar node)
132 (declare (type lvar lvar) (type node node))
133 (aver (eq (node-lvar node) lvar))
134 (let ((dest (lvar-dest lvar)))
135 (acond ((node-next node)
136 (eq (ctran-next it) dest))
137 (t (eq (block-start (first (block-succ (node-block node))))
138 (node-prev dest))))))
140 ;;;; lvar substitution
142 ;;; In OLD's DEST, replace OLD with NEW. NEW's DEST must initially be
143 ;;; NIL. We do not flush OLD's DEST.
144 (defun substitute-lvar (new old)
145 (declare (type lvar old new))
146 (aver (not (lvar-dest new)))
147 (let ((dest (lvar-dest old)))
150 (cif (setf (if-test dest) new))
151 (cset (setf (set-value dest) new))
152 (creturn (setf (return-result dest) new))
153 (exit (setf (exit-value dest) new))
155 (if (eq old (basic-combination-fun dest))
156 (setf (basic-combination-fun dest) new)
157 (setf (basic-combination-args dest)
158 (nsubst new old (basic-combination-args dest)))))
159 (cast (setf (cast-value dest) new)))
161 (setf (lvar-dest old) nil)
162 (setf (lvar-dest new) dest)
163 (flush-lvar-externally-checkable-type new))
166 ;;; Replace all uses of OLD with uses of NEW, where NEW has an
167 ;;; arbitary number of uses.
168 (defun substitute-lvar-uses (new old)
169 (declare (type lvar old)
170 (type (or lvar null) new))
172 (cond (new (do-uses (node old)
173 (%delete-lvar-use node)
174 (add-lvar-use node new))
175 (reoptimize-lvar new))
176 (t (flush-dest old)))
179 ;;;; block starting/creation
181 ;;; Return the block that CTRAN is the start of, making a block if
182 ;;; necessary. This function is called by IR1 translators which may
183 ;;; cause a CTRAN to be used more than once. Every CTRAN which may be
184 ;;; used more than once must start a block by the time that anyone
185 ;;; does a USE-CTRAN on it.
187 ;;; We also throw the block into the next/prev list for the
188 ;;; *CURRENT-COMPONENT* so that we keep track of which blocks we have
190 (defun ctran-starts-block (ctran)
191 (declare (type ctran ctran))
192 (ecase (ctran-kind ctran)
194 (aver (not (ctran-block ctran)))
195 (let* ((next (component-last-block *current-component*))
196 (prev (block-prev next))
197 (new-block (make-block ctran)))
198 (setf (block-next new-block) next
199 (block-prev new-block) prev
200 (block-prev next) new-block
201 (block-next prev) new-block
202 (ctran-block ctran) new-block
203 (ctran-kind ctran) :block-start)
204 (aver (not (ctran-use ctran)))
207 (ctran-block ctran))))
209 ;;; Ensure that CTRAN is the start of a block so that the use set can
210 ;;; be freely manipulated.
211 (defun ensure-block-start (ctran)
212 (declare (type ctran ctran))
213 (let ((kind (ctran-kind ctran)))
217 (setf (ctran-block ctran)
218 (make-block-key :start ctran))
219 (setf (ctran-kind ctran) :block-start))
221 (node-ends-block (ctran-use ctran)))))
224 ;;; CTRAN must be the last ctran in an incomplete block; finish the
225 ;;; block and start a new one if necessary.
226 (defun start-block (ctran)
227 (declare (type ctran ctran))
228 (aver (not (ctran-next ctran)))
229 (ecase (ctran-kind ctran)
231 (let ((block (ctran-block ctran))
232 (node (ctran-use ctran)))
233 (aver (not (block-last block)))
235 (setf (block-last block) node)
236 (setf (node-next node) nil)
237 (setf (ctran-use ctran) nil)
238 (setf (ctran-kind ctran) :unused)
239 (setf (ctran-block ctran) nil)
240 (link-blocks block (ctran-starts-block ctran))))
245 ;;; Filter values of LVAR through FORM, which must be an ordinary/mv
246 ;;; call. First argument must be 'DUMMY, which will be replaced with
247 ;;; LVAR. In case of an ordinary call the function should not have
248 ;;; return type NIL. We create a new "filtered" lvar.
250 ;;; TODO: remove preconditions.
251 (defun filter-lvar (lvar form)
252 (declare (type lvar lvar) (type list form))
253 (let* ((dest (lvar-dest lvar))
254 (ctran (node-prev dest)))
255 (with-ir1-environment-from-node dest
257 (ensure-block-start ctran)
258 (let* ((old-block (ctran-block ctran))
259 (new-start (make-ctran))
260 (filtered-lvar (make-lvar))
261 (new-block (ctran-starts-block new-start)))
263 ;; Splice in the new block before DEST, giving the new block
264 ;; all of DEST's predecessors.
265 (dolist (block (block-pred old-block))
266 (change-block-successor block old-block new-block))
268 (ir1-convert new-start ctran filtered-lvar form)
270 ;; KLUDGE: Comments at the head of this function in CMU CL
271 ;; said that somewhere in here we
272 ;; Set the new block's start and end cleanups to the *start*
273 ;; cleanup of PREV's block. This overrides the incorrect
274 ;; default from WITH-IR1-ENVIRONMENT-FROM-NODE.
275 ;; Unfortunately I can't find any code which corresponds to this.
276 ;; Perhaps it was a stale comment? Or perhaps I just don't
277 ;; understand.. -- WHN 19990521
279 ;; Replace 'DUMMY with the LVAR. (We can find 'DUMMY because
280 ;; no LET conversion has been done yet.) The [mv-]combination
281 ;; code from the call in the form will be the use of the new
282 ;; check lvar. We substitute for the first argument of
284 (let* ((node (lvar-use filtered-lvar))
285 (args (basic-combination-args node))
286 (victim (first args)))
287 (aver (eq (constant-value (ref-leaf (lvar-use victim)))
290 (substitute-lvar filtered-lvar lvar)
291 (substitute-lvar lvar victim)
294 ;; Invoking local call analysis converts this call to a LET.
295 (locall-analyze-component *current-component*))))
298 ;;; Delete NODE and VALUE. It may result in some calls becoming tail.
299 (defun delete-filter (node lvar value)
300 (aver (eq (lvar-dest value) node))
301 (aver (eq (node-lvar node) lvar))
302 (cond (lvar (collect ((merges))
303 (when (return-p (lvar-dest lvar))
305 (when (and (basic-combination-p use)
306 (eq (basic-combination-kind use) :local))
308 (%delete-lvar-use node)
309 (substitute-lvar-uses lvar value)
312 (dolist (merge (merges))
313 (merge-tail-sets merge)))))
314 (t (flush-dest value)
315 (unlink-node node))))
317 ;;;; miscellaneous shorthand functions
319 ;;; Return the home (i.e. enclosing non-LET) CLAMBDA for NODE. Since
320 ;;; the LEXENV-LAMBDA may be deleted, we must chain up the
321 ;;; LAMBDA-CALL-LEXENV thread until we find a CLAMBDA that isn't
322 ;;; deleted, and then return its home.
323 (defun node-home-lambda (node)
324 (declare (type node node))
325 (do ((fun (lexenv-lambda (node-lexenv node))
326 (lexenv-lambda (lambda-call-lexenv fun))))
327 ((not (memq (functional-kind fun) '(:deleted :zombie)))
329 (when (eq (lambda-home fun) fun)
332 #!-sb-fluid (declaim (inline node-block))
333 (defun node-block (node)
334 (ctran-block (node-prev node)))
335 (declaim (ftype (sfunction (node) component) node-component))
336 (defun node-component (node)
337 (block-component (node-block node)))
338 (declaim (ftype (sfunction (node) physenv) node-physenv))
339 (defun node-physenv (node)
340 (lambda-physenv (node-home-lambda node)))
341 #!-sb-fluid (declaim (inline node-dest))
342 (defun node-dest (node)
343 (awhen (node-lvar node) (lvar-dest it)))
345 (declaim (inline block-to-be-deleted-p))
346 (defun block-to-be-deleted-p (block)
347 (or (block-delete-p block)
348 (eq (functional-kind (block-home-lambda block)) :deleted)))
350 ;;; Checks whether NODE is in a block to be deleted
351 (declaim (inline node-to-be-deleted-p))
352 (defun node-to-be-deleted-p (node)
353 (block-to-be-deleted-p (node-block node)))
355 (declaim (ftype (sfunction (clambda) cblock) lambda-block))
356 (defun lambda-block (clambda)
357 (node-block (lambda-bind clambda)))
358 (declaim (ftype (sfunction (clambda) component) lambda-component))
359 (defun lambda-component (clambda)
360 (block-component (lambda-block clambda)))
362 (declaim (ftype (sfunction (cblock) node) block-start-node))
363 (defun block-start-node (block)
364 (ctran-next (block-start block)))
366 ;;; Return the enclosing cleanup for environment of the first or last
368 (defun block-start-cleanup (block)
369 (node-enclosing-cleanup (block-start-node block)))
370 (defun block-end-cleanup (block)
371 (node-enclosing-cleanup (block-last block)))
373 ;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
374 ;;; if there is none.
376 ;;; There can legitimately be no home lambda in dead code early in the
377 ;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
378 ;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
379 ;;; where the block is just a placeholder during parsing and doesn't
380 ;;; actually correspond to code which will be written anywhere.
381 (declaim (ftype (sfunction (cblock) (or clambda null)) block-home-lambda-or-null))
382 (defun block-home-lambda-or-null (block)
383 (if (node-p (block-last block))
384 ;; This is the old CMU CL way of doing it.
385 (node-home-lambda (block-last block))
386 ;; Now that SBCL uses this operation more aggressively than CMU
387 ;; CL did, the old CMU CL way of doing it can fail in two ways.
388 ;; 1. It can fail in a few cases even when a meaningful home
389 ;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
391 ;; 2. It can fail when converting a form which is born orphaned
392 ;; so that it never had a meaningful home lambda, e.g. a form
393 ;; which follows a RETURN-FROM or GO form.
394 (let ((pred-list (block-pred block)))
395 ;; To deal with case 1, we reason that
396 ;; previous-in-target-execution-order blocks should be in the
397 ;; same lambda, and that they seem in practice to be
398 ;; previous-in-compilation-order blocks too, so we look back
399 ;; to find one which is sufficiently initialized to tell us
400 ;; what the home lambda is.
402 ;; We could get fancy about this, flooding through the
403 ;; graph of all the previous blocks, but in practice it
404 ;; seems to work just to grab the first previous block and
406 (node-home-lambda (block-last (first pred-list)))
407 ;; In case 2, we end up with an empty PRED-LIST and
408 ;; have to punt: There's no home lambda.
411 ;;; Return the non-LET LAMBDA that holds BLOCK's code.
412 (declaim (ftype (sfunction (cblock) clambda) block-home-lambda))
413 (defun block-home-lambda (block)
414 (block-home-lambda-or-null block))
416 ;;; Return the IR1 physical environment for BLOCK.
417 (declaim (ftype (sfunction (cblock) physenv) block-physenv))
418 (defun block-physenv (block)
419 (lambda-physenv (block-home-lambda block)))
421 ;;; Return the Top Level Form number of PATH, i.e. the ordinal number
422 ;;; of its original source's top level form in its compilation unit.
423 (defun source-path-tlf-number (path)
424 (declare (list path))
427 ;;; Return the (reversed) list for the PATH in the original source
428 ;;; (with the Top Level Form number last).
429 (defun source-path-original-source (path)
430 (declare (list path) (inline member))
431 (cddr (member 'original-source-start path :test #'eq)))
433 ;;; Return the Form Number of PATH's original source inside the Top
434 ;;; Level Form that contains it. This is determined by the order that
435 ;;; we walk the subforms of the top level source form.
436 (defun source-path-form-number (path)
437 (declare (list path) (inline member))
438 (cadr (member 'original-source-start path :test #'eq)))
440 ;;; Return a list of all the enclosing forms not in the original
441 ;;; source that converted to get to this form, with the immediate
442 ;;; source for node at the start of the list.
443 (defun source-path-forms (path)
444 (subseq path 0 (position 'original-source-start path)))
446 ;;; Return the innermost source form for NODE.
447 (defun node-source-form (node)
448 (declare (type node node))
449 (let* ((path (node-source-path node))
450 (forms (source-path-forms path)))
453 (values (find-original-source path)))))
455 ;;; Return NODE-SOURCE-FORM, T if lvar has a single use, otherwise
457 (defun lvar-source (lvar)
458 (let ((use (lvar-uses lvar)))
461 (values (node-source-form use) t))))
463 ;;; Return the unique node, delivering a value to LVAR.
464 #!-sb-fluid (declaim (inline lvar-use))
465 (defun lvar-use (lvar)
466 (the (not list) (lvar-uses lvar)))
468 #!-sb-fluid (declaim (inline lvar-has-single-use-p))
469 (defun lvar-has-single-use-p (lvar)
470 (typep (lvar-uses lvar) '(not list)))
472 ;;; Return the LAMBDA that is CTRAN's home, or NIL if there is none.
473 (declaim (ftype (sfunction (ctran) (or clambda null))
474 ctran-home-lambda-or-null))
475 (defun ctran-home-lambda-or-null (ctran)
476 ;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
477 ;; implementation might not be quite right, or might be uglier than
478 ;; necessary. It appears that the original Python never found a need
479 ;; to do this operation. The obvious things based on
480 ;; NODE-HOME-LAMBDA of CTRAN-USE usually work; then if that fails,
481 ;; BLOCK-HOME-LAMBDA of CTRAN-BLOCK works, given that we
482 ;; generalize it enough to grovel harder when the simple CMU CL
483 ;; approach fails, and furthermore realize that in some exceptional
484 ;; cases it might return NIL. -- WHN 2001-12-04
485 (cond ((ctran-use ctran)
486 (node-home-lambda (ctran-use ctran)))
488 (block-home-lambda-or-null (ctran-block ctran)))
490 (bug "confused about home lambda for ~S" ctran))))
492 ;;; Return the LAMBDA that is CTRAN's home.
493 (declaim (ftype (sfunction (ctran) clambda) ctran-home-lambda))
494 (defun ctran-home-lambda (ctran)
495 (ctran-home-lambda-or-null ctran))
497 (declaim (inline cast-single-value-p))
498 (defun cast-single-value-p (cast)
499 (not (values-type-p (cast-asserted-type cast))))
501 #!-sb-fluid (declaim (inline lvar-single-value-p))
502 (defun lvar-single-value-p (lvar)
504 (let ((dest (lvar-dest lvar)))
509 (eq (basic-combination-fun dest) lvar))
512 (declare (notinline lvar-single-value-p))
513 (and (cast-single-value-p dest)
514 (lvar-single-value-p (node-lvar dest)))))
518 (defun principal-lvar-end (lvar)
519 (loop for prev = lvar then (node-lvar dest)
520 for dest = (and prev (lvar-dest prev))
522 finally (return (values dest prev))))
524 (defun principal-lvar-single-valuify (lvar)
525 (loop for prev = lvar then (node-lvar dest)
526 for dest = (and prev (lvar-dest prev))
528 do (setf (node-derived-type dest)
529 (make-short-values-type (list (single-value-type
530 (node-derived-type dest)))))
531 (reoptimize-lvar prev)))
533 ;;; Return a new LEXENV just like DEFAULT except for the specified
534 ;;; slot values. Values for the alist slots are NCONCed to the
535 ;;; beginning of the current value, rather than replacing it entirely.
536 (defun make-lexenv (&key (default *lexenv*)
537 funs vars blocks tags
539 (lambda (lexenv-lambda default))
540 (cleanup (lexenv-cleanup default))
541 (handled-conditions (lexenv-handled-conditions default))
542 (disabled-package-locks
543 (lexenv-disabled-package-locks default))
544 (policy (lexenv-policy default)))
545 (macrolet ((frob (var slot)
546 `(let ((old (,slot default)))
550 (internal-make-lexenv
551 (frob funs lexenv-funs)
552 (frob vars lexenv-vars)
553 (frob blocks lexenv-blocks)
554 (frob tags lexenv-tags)
555 (frob type-restrictions lexenv-type-restrictions)
556 lambda cleanup handled-conditions
557 disabled-package-locks policy)))
559 ;;; Makes a LEXENV, suitable for using in a MACROLET introduced
561 (defun make-restricted-lexenv (lexenv)
562 (flet ((fun-good-p (fun)
563 (destructuring-bind (name . thing) fun
564 (declare (ignore name))
568 (cons (aver (eq (car thing) 'macro))
571 (destructuring-bind (name . thing) var
572 (declare (ignore name))
575 (cons (aver (eq (car thing) 'macro))
577 (heap-alien-info nil)))))
578 (internal-make-lexenv
579 (remove-if-not #'fun-good-p (lexenv-funs lexenv))
580 (remove-if-not #'var-good-p (lexenv-vars lexenv))
583 (lexenv-type-restrictions lexenv) ; XXX
586 (lexenv-handled-conditions lexenv)
587 (lexenv-disabled-package-locks lexenv)
588 (lexenv-policy lexenv))))
590 ;;;; flow/DFO/component hackery
592 ;;; Join BLOCK1 and BLOCK2.
593 (defun link-blocks (block1 block2)
594 (declare (type cblock block1 block2))
595 (setf (block-succ block1)
596 (if (block-succ block1)
597 (%link-blocks block1 block2)
599 (push block1 (block-pred block2))
601 (defun %link-blocks (block1 block2)
602 (declare (type cblock block1 block2))
603 (let ((succ1 (block-succ block1)))
604 (aver (not (memq block2 succ1)))
605 (cons block2 succ1)))
607 ;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
608 ;;; this leaves a successor with a single predecessor that ends in an
609 ;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
610 ;;; now be able to be propagated to the successor.
611 (defun unlink-blocks (block1 block2)
612 (declare (type cblock block1 block2))
613 (let ((succ1 (block-succ block1)))
614 (if (eq block2 (car succ1))
615 (setf (block-succ block1) (cdr succ1))
616 (do ((succ (cdr succ1) (cdr succ))
618 ((eq (car succ) block2)
619 (setf (cdr prev) (cdr succ)))
622 (let ((new-pred (delq block1 (block-pred block2))))
623 (setf (block-pred block2) new-pred)
624 (when (singleton-p new-pred)
625 (let ((pred-block (first new-pred)))
626 (when (if-p (block-last pred-block))
627 (setf (block-test-modified pred-block) t)))))
630 ;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
631 ;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
632 ;;; consequent/alternative blocks to point to NEW. We also set
633 ;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
634 ;;; the new successor.
635 (defun change-block-successor (block old new)
636 (declare (type cblock new old block))
637 (unlink-blocks block old)
638 (let ((last (block-last block))
639 (comp (block-component block)))
640 (setf (component-reanalyze comp) t)
643 (setf (block-test-modified block) t)
644 (let* ((succ-left (block-succ block))
645 (new (if (and (eq new (component-tail comp))
649 (unless (memq new succ-left)
650 (link-blocks block new))
651 (macrolet ((frob (slot)
652 `(when (eq (,slot last) old)
653 (setf (,slot last) new))))
655 (frob if-alternative)
656 (when (eq (if-consequent last)
657 (if-alternative last))
658 (setf (component-reoptimize (block-component block)) t)))))
660 (unless (memq new (block-succ block))
661 (link-blocks block new)))))
665 ;;; Unlink a block from the next/prev chain. We also null out the
667 (declaim (ftype (sfunction (cblock) (values)) remove-from-dfo))
668 (defun remove-from-dfo (block)
669 (let ((next (block-next block))
670 (prev (block-prev block)))
671 (setf (block-component block) nil)
672 (setf (block-next prev) next)
673 (setf (block-prev next) prev))
676 ;;; Add BLOCK to the next/prev chain following AFTER. We also set the
677 ;;; COMPONENT to be the same as for AFTER.
678 (defun add-to-dfo (block after)
679 (declare (type cblock block after))
680 (let ((next (block-next after))
681 (comp (block-component after)))
682 (aver (not (eq (component-kind comp) :deleted)))
683 (setf (block-component block) comp)
684 (setf (block-next after) block)
685 (setf (block-prev block) after)
686 (setf (block-next block) next)
687 (setf (block-prev next) block))
690 ;;; List all NLX-INFOs which BLOCK can exit to.
692 ;;; We hope that no cleanup actions are performed in the middle of
693 ;;; BLOCK, so it is enough to look only at cleanups in the block
694 ;;; end. The tricky thing is a special cleanup block; all its nodes
695 ;;; have the same cleanup info, corresponding to the start, so the
696 ;;; same approach returns safe result.
697 (defun map-block-nlxes (fun block)
698 (loop for cleanup = (block-end-cleanup block)
699 then (node-enclosing-cleanup (cleanup-mess-up cleanup))
701 do (let ((mess-up (cleanup-mess-up cleanup)))
702 (case (cleanup-kind cleanup)
704 (aver (entry-p mess-up))
705 (loop for exit in (entry-exits mess-up)
706 for nlx-info = (find-nlx-info exit)
707 do (funcall fun nlx-info)))
708 ((:catch :unwind-protect)
709 (aver (combination-p mess-up))
710 (let* ((arg-lvar (first (basic-combination-args mess-up)))
711 (nlx-info (constant-value (ref-leaf (lvar-use arg-lvar)))))
712 (funcall fun nlx-info)))))))
714 ;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
715 ;;; the head and tail which are set to T.
716 (declaim (ftype (sfunction (component) (values)) clear-flags))
717 (defun clear-flags (component)
718 (let ((head (component-head component))
719 (tail (component-tail component)))
720 (setf (block-flag head) t)
721 (setf (block-flag tail) t)
722 (do-blocks (block component)
723 (setf (block-flag block) nil)))
726 ;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
727 ;;; true in the head and tail blocks.
728 (declaim (ftype (sfunction () component) make-empty-component))
729 (defun make-empty-component ()
730 (let* ((head (make-block-key :start nil :component nil))
731 (tail (make-block-key :start nil :component nil))
732 (res (make-component head tail)))
733 (setf (block-flag head) t)
734 (setf (block-flag tail) t)
735 (setf (block-component head) res)
736 (setf (block-component tail) res)
737 (setf (block-next head) tail)
738 (setf (block-prev tail) head)
741 ;;; Make NODE the LAST node in its block, splitting the block if necessary.
742 ;;; The new block is added to the DFO immediately following NODE's block.
743 (defun node-ends-block (node)
744 (declare (type node node))
745 (let* ((block (node-block node))
746 (start (node-next node))
747 (last (block-last block)))
748 (unless (eq last node)
749 (aver (and (eq (ctran-kind start) :inside-block)
750 (not (block-delete-p block))))
751 (let* ((succ (block-succ block))
753 (make-block-key :start start
754 :component (block-component block)
755 :succ succ :last last)))
756 (setf (ctran-kind start) :block-start)
757 (setf (ctran-use start) nil)
758 (setf (block-last block) node)
759 (setf (node-next node) nil)
762 (cons new-block (remove block (block-pred b)))))
763 (setf (block-succ block) ())
764 (link-blocks block new-block)
765 (add-to-dfo new-block block)
766 (setf (component-reanalyze (block-component block)) t)
768 (do ((ctran start (node-next (ctran-next ctran))))
770 (setf (ctran-block ctran) new-block))
772 (setf (block-type-asserted block) t)
773 (setf (block-test-modified block) t))))
778 ;;; Deal with deleting the last (read) reference to a LAMBDA-VAR.
779 (defun delete-lambda-var (leaf)
780 (declare (type lambda-var leaf))
782 ;; Iterate over all local calls flushing the corresponding argument,
783 ;; allowing the computation of the argument to be deleted. We also
784 ;; mark the LET for reoptimization, since it may be that we have
785 ;; deleted its last variable.
786 (let* ((fun (lambda-var-home leaf))
787 (n (position leaf (lambda-vars fun))))
788 (dolist (ref (leaf-refs fun))
789 (let* ((lvar (node-lvar ref))
790 (dest (and lvar (lvar-dest lvar))))
791 (when (and (combination-p dest)
792 (eq (basic-combination-fun dest) lvar)
793 (eq (basic-combination-kind dest) :local))
794 (let* ((args (basic-combination-args dest))
796 (reoptimize-lvar arg)
798 (setf (elt args n) nil))))))
800 ;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
801 ;; too much difficulty, since we can efficiently implement
802 ;; write-only variables. We iterate over the SETs, marking their
803 ;; blocks for dead code flushing, since we can delete SETs whose
805 (dolist (set (lambda-var-sets leaf))
806 (setf (block-flush-p (node-block set)) t))
810 ;;; Note that something interesting has happened to VAR.
811 (defun reoptimize-lambda-var (var)
812 (declare (type lambda-var var))
813 (let ((fun (lambda-var-home var)))
814 ;; We only deal with LET variables, marking the corresponding
815 ;; initial value arg as needing to be reoptimized.
816 (when (and (eq (functional-kind fun) :let)
818 (do ((args (basic-combination-args
819 (lvar-dest (node-lvar (first (leaf-refs fun)))))
821 (vars (lambda-vars fun) (cdr vars)))
823 (reoptimize-lvar (car args))))))
826 ;;; Delete a function that has no references. This need only be called
827 ;;; on functions that never had any references, since otherwise
828 ;;; DELETE-REF will handle the deletion.
829 (defun delete-functional (fun)
830 (aver (and (null (leaf-refs fun))
831 (not (functional-entry-fun fun))))
833 (optional-dispatch (delete-optional-dispatch fun))
834 (clambda (delete-lambda fun)))
837 ;;; Deal with deleting the last reference to a CLAMBDA, which means
838 ;;; that the lambda is unreachable, so that its body may be
839 ;;; deleted. We set FUNCTIONAL-KIND to :DELETED and rely on
840 ;;; IR1-OPTIMIZE to delete its blocks.
841 (defun delete-lambda (clambda)
842 (declare (type clambda clambda))
843 (let ((original-kind (functional-kind clambda))
844 (bind (lambda-bind clambda)))
845 (aver (not (member original-kind '(:deleted :toplevel))))
846 (aver (not (functional-has-external-references-p clambda)))
847 (aver (or (eq original-kind :zombie) bind))
848 (setf (functional-kind clambda) :deleted)
849 (setf (lambda-bind clambda) nil)
851 (labels ((delete-children (lambda)
852 (dolist (child (lambda-children lambda))
853 (cond ((eq (functional-kind child) :deleted)
854 (delete-children child))
856 (delete-lambda child))))
857 (setf (lambda-children lambda) nil)
858 (setf (lambda-parent lambda) nil)))
859 (delete-children clambda))
861 ;; (The IF test is (FUNCTIONAL-SOMEWHAT-LETLIKE-P CLAMBDA), except
862 ;; that we're using the old value of the KIND slot, not the
863 ;; current slot value, which has now been set to :DELETED.)
866 ((:let :mv-let :assignment)
867 (let ((bind-block (node-block bind)))
868 (mark-for-deletion bind-block))
869 (let ((home (lambda-home clambda)))
870 (setf (lambda-lets home) (delete clambda (lambda-lets home))))
871 ;; KLUDGE: In presence of NLEs we cannot always understand that
872 ;; LET's BIND dominates its body [for a LET "its" body is not
873 ;; quite its]; let's delete too dangerous for IR2 stuff. --
875 (dolist (var (lambda-vars clambda))
876 (flet ((delete-node (node)
877 (mark-for-deletion (node-block node))))
878 (mapc #'delete-node (leaf-refs var))
879 (mapc #'delete-node (lambda-var-sets var)))))
881 ;; Function has no reachable references.
882 (dolist (ref (lambda-refs clambda))
883 (mark-for-deletion (node-block ref)))
884 ;; If the function isn't a LET, we unlink the function head
885 ;; and tail from the component head and tail to indicate that
886 ;; the code is unreachable. We also delete the function from
887 ;; COMPONENT-LAMBDAS (it won't be there before local call
888 ;; analysis, but no matter.) If the lambda was never
889 ;; referenced, we give a note.
890 (let* ((bind-block (node-block bind))
891 (component (block-component bind-block))
892 (return (lambda-return clambda))
893 (return-block (and return (node-block return))))
894 (unless (leaf-ever-used clambda)
895 (let ((*compiler-error-context* bind))
896 (compiler-notify 'code-deletion-note
897 :format-control "deleting unused function~:[.~;~:*~% ~S~]"
898 :format-arguments (list (leaf-debug-name clambda)))))
899 (unless (block-delete-p bind-block)
900 (unlink-blocks (component-head component) bind-block))
901 (when (and return-block (not (block-delete-p return-block)))
902 (mark-for-deletion return-block)
903 (unlink-blocks return-block (component-tail component)))
904 (setf (component-reanalyze component) t)
905 (let ((tails (lambda-tail-set clambda)))
906 (setf (tail-set-funs tails)
907 (delete clambda (tail-set-funs tails)))
908 (setf (lambda-tail-set clambda) nil))
909 (setf (component-lambdas component)
910 (delq clambda (component-lambdas component))))))
912 ;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
913 ;; ENTRY-FUN so that people will know that it is not an entry
915 (when (eq original-kind :external)
916 (let ((fun (functional-entry-fun clambda)))
917 (setf (functional-entry-fun fun) nil)
918 (when (optional-dispatch-p fun)
919 (delete-optional-dispatch fun)))))
923 ;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
924 ;;; have to be a bit more careful than with lambdas, since DELETE-REF
925 ;;; is used both before and after local call analysis. Afterward, all
926 ;;; references to still-existing OPTIONAL-DISPATCHes have been moved
927 ;;; to the XEP, leaving it with no references at all. So we look at
928 ;;; the XEP to see whether an optional-dispatch is still really being
929 ;;; used. But before local call analysis, there are no XEPs, and all
930 ;;; references are direct.
932 ;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
933 ;;; entry-points, making them be normal lambdas, and then deleting the
934 ;;; ones with no references. This deletes any e-p lambdas that were
935 ;;; either never referenced, or couldn't be deleted when the last
936 ;;; reference was deleted (due to their :OPTIONAL kind.)
938 ;;; Note that the last optional entry point may alias the main entry,
939 ;;; so when we process the main entry, its KIND may have been changed
940 ;;; to NIL or even converted to a LETlike value.
941 (defun delete-optional-dispatch (leaf)
942 (declare (type optional-dispatch leaf))
943 (let ((entry (functional-entry-fun leaf)))
944 (unless (and entry (leaf-refs entry))
945 (aver (or (not entry) (eq (functional-kind entry) :deleted)))
946 (setf (functional-kind leaf) :deleted)
949 (unless (eq (functional-kind fun) :deleted)
950 (aver (eq (functional-kind fun) :optional))
951 (setf (functional-kind fun) nil)
952 (let ((refs (leaf-refs fun)))
956 (or (maybe-let-convert fun)
957 (maybe-convert-to-assignment fun)))
959 (maybe-convert-to-assignment fun)))))))
961 (dolist (ep (optional-dispatch-entry-points leaf))
962 (when (promise-ready-p ep)
964 (when (optional-dispatch-more-entry leaf)
965 (frob (optional-dispatch-more-entry leaf)))
966 (let ((main (optional-dispatch-main-entry leaf)))
967 (when (eq (functional-kind main) :optional)
972 ;;; Do stuff to delete the semantic attachments of a REF node. When
973 ;;; this leaves zero or one reference, we do a type dispatch off of
974 ;;; the leaf to determine if a special action is appropriate.
975 (defun delete-ref (ref)
976 (declare (type ref ref))
977 (let* ((leaf (ref-leaf ref))
978 (refs (delq ref (leaf-refs leaf))))
979 (setf (leaf-refs leaf) refs)
984 (delete-lambda-var leaf))
986 (ecase (functional-kind leaf)
987 ((nil :let :mv-let :assignment :escape :cleanup)
988 (aver (null (functional-entry-fun leaf)))
989 (delete-lambda leaf))
991 (delete-lambda leaf))
992 ((:deleted :zombie :optional))))
994 (unless (eq (functional-kind leaf) :deleted)
995 (delete-optional-dispatch leaf)))))
998 (clambda (or (maybe-let-convert leaf)
999 (maybe-convert-to-assignment leaf)))
1000 (lambda-var (reoptimize-lambda-var leaf))))
1003 (clambda (maybe-convert-to-assignment leaf))))))
1007 ;;; This function is called by people who delete nodes; it provides a
1008 ;;; way to indicate that the value of a lvar is no longer used. We
1009 ;;; null out the LVAR-DEST, set FLUSH-P in the blocks containing uses
1010 ;;; of LVAR and set COMPONENT-REOPTIMIZE.
1011 (defun flush-dest (lvar)
1012 (declare (type (or lvar null) lvar))
1014 (setf (lvar-dest lvar) nil)
1015 (flush-lvar-externally-checkable-type lvar)
1017 (let ((prev (node-prev use)))
1018 (let ((block (ctran-block prev)))
1019 (setf (component-reoptimize (block-component block)) t)
1020 (setf (block-attributep (block-flags block)
1021 flush-p type-asserted type-check)
1023 (setf (node-lvar use) nil))
1024 (setf (lvar-uses lvar) nil))
1027 (defun delete-dest (lvar)
1029 (let* ((dest (lvar-dest lvar))
1030 (prev (node-prev dest)))
1031 (let ((block (ctran-block prev)))
1032 (unless (block-delete-p block)
1033 (mark-for-deletion block))))))
1035 ;;; Queue the block for deletion
1036 (defun delete-block-lazily (block)
1037 (declare (type cblock block))
1038 (unless (block-delete-p block)
1039 (setf (block-delete-p block) t)
1040 (push block (component-delete-blocks (block-component block)))))
1042 ;;; Do a graph walk backward from BLOCK, marking all predecessor
1043 ;;; blocks with the DELETE-P flag.
1044 (defun mark-for-deletion (block)
1045 (declare (type cblock block))
1046 (let* ((component (block-component block))
1047 (head (component-head component)))
1048 (labels ((helper (block)
1049 (delete-block-lazily block)
1050 (dolist (pred (block-pred block))
1051 (unless (or (block-delete-p pred)
1054 (unless (block-delete-p block)
1056 (setf (component-reanalyze component) t))))
1059 ;;; This function does what is necessary to eliminate the code in it
1060 ;;; from the IR1 representation. This involves unlinking it from its
1061 ;;; predecessors and successors and deleting various node-specific
1062 ;;; semantic information. BLOCK must be already removed from
1063 ;;; COMPONENT-DELETE-BLOCKS.
1064 (defun delete-block (block &optional silent)
1065 (declare (type cblock block))
1066 (aver (block-component block)) ; else block is already deleted!
1067 #!+high-security (aver (not (memq block (component-delete-blocks (block-component block)))))
1069 (note-block-deletion block))
1070 (setf (block-delete-p block) t)
1072 (dolist (b (block-pred block))
1073 (unlink-blocks b block)
1074 ;; In bug 147 the almost-all-blocks-have-a-successor invariant was
1075 ;; broken when successors were deleted without setting the
1076 ;; BLOCK-DELETE-P flags of their predececessors. Make sure that
1077 ;; doesn't happen again.
1078 (aver (not (and (null (block-succ b))
1079 (not (block-delete-p b))
1080 (not (eq b (component-head (block-component b))))))))
1081 (dolist (b (block-succ block))
1082 (unlink-blocks block b))
1084 (do-nodes-carefully (node block)
1085 (when (valued-node-p node)
1086 (delete-lvar-use node))
1088 (ref (delete-ref node))
1089 (cif (flush-dest (if-test node)))
1090 ;; The next two cases serve to maintain the invariant that a LET
1091 ;; always has a well-formed COMBINATION, REF and BIND. We delete
1092 ;; the lambda whenever we delete any of these, but we must be
1093 ;; careful that this LET has not already been partially deleted.
1095 (when (and (eq (basic-combination-kind node) :local)
1096 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
1097 (lvar-uses (basic-combination-fun node)))
1098 (let ((fun (combination-lambda node)))
1099 ;; If our REF was the second-to-last ref, and has been
1100 ;; deleted, then FUN may be a LET for some other
1102 (when (and (functional-letlike-p fun)
1103 (eq (let-combination fun) node))
1104 (delete-lambda fun))))
1105 (flush-dest (basic-combination-fun node))
1106 (dolist (arg (basic-combination-args node))
1107 (when arg (flush-dest arg))))
1109 (let ((lambda (bind-lambda node)))
1110 (unless (eq (functional-kind lambda) :deleted)
1111 (delete-lambda lambda))))
1113 (let ((value (exit-value node))
1114 (entry (exit-entry node)))
1118 (setf (entry-exits entry)
1119 (delq node (entry-exits entry))))))
1121 (dolist (exit (entry-exits node))
1122 (mark-for-deletion (node-block exit)))
1123 (let ((home (node-home-lambda node)))
1124 (setf (lambda-entries home) (delq node (lambda-entries home)))))
1126 (flush-dest (return-result node))
1127 (delete-return node))
1129 (flush-dest (set-value node))
1130 (let ((var (set-var node)))
1131 (setf (basic-var-sets var)
1132 (delete node (basic-var-sets var)))))
1134 (flush-dest (cast-value node)))))
1136 (remove-from-dfo block)
1139 ;;; Do stuff to indicate that the return node NODE is being deleted.
1140 (defun delete-return (node)
1141 (declare (type creturn node))
1142 (let* ((fun (return-lambda node))
1143 (tail-set (lambda-tail-set fun)))
1144 (aver (lambda-return fun))
1145 (setf (lambda-return fun) nil)
1146 (when (and tail-set (not (find-if #'lambda-return
1147 (tail-set-funs tail-set))))
1148 (setf (tail-set-type tail-set) *empty-type*)))
1151 ;;; If any of the VARS in FUN was never referenced and was not
1152 ;;; declared IGNORE, then complain.
1153 (defun note-unreferenced-vars (fun)
1154 (declare (type clambda fun))
1155 (dolist (var (lambda-vars fun))
1156 (unless (or (leaf-ever-used var)
1157 (lambda-var-ignorep var))
1158 (let ((*compiler-error-context* (lambda-bind fun)))
1159 (unless (policy *compiler-error-context* (= inhibit-warnings 3))
1160 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
1161 ;; requires this to be no more than a STYLE-WARNING.
1163 (compiler-style-warn "The variable ~S is defined but never used."
1164 (leaf-debug-name var))
1165 ;; There's no reason to accept this kind of equivocation
1166 ;; when compiling our own code, though.
1168 (warn "The variable ~S is defined but never used."
1169 (leaf-debug-name var)))
1170 (setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
1173 (defvar *deletion-ignored-objects* '(t nil))
1175 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
1176 ;;; our recursion so that we don't get lost in circular structures. We
1177 ;;; ignore the car of forms if they are a symbol (to prevent confusing
1178 ;;; function referencess with variables), and we also ignore anything
1180 (defun present-in-form (obj form depth)
1181 (declare (type (integer 0 20) depth))
1182 (cond ((= depth 20) nil)
1186 (let ((first (car form))
1188 (if (member first '(quote function))
1190 (or (and (not (symbolp first))
1191 (present-in-form obj first depth))
1192 (do ((l (cdr form) (cdr l))
1194 ((or (atom l) (> n 100))
1196 (declare (fixnum n))
1197 (when (present-in-form obj (car l) depth)
1200 ;;; This function is called on a block immediately before we delete
1201 ;;; it. We check to see whether any of the code about to die appeared
1202 ;;; in the original source, and emit a note if so.
1204 ;;; If the block was in a lambda is now deleted, then we ignore the
1205 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
1206 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
1207 ;;; reasonable for a function to not return, and there is a different
1208 ;;; note for that case anyway.
1210 ;;; If the actual source is an atom, then we use a bunch of heuristics
1211 ;;; to guess whether this reference really appeared in the original
1213 ;;; -- If a symbol, it must be interned and not a keyword.
1214 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
1215 ;;; or a character.)
1216 ;;; -- The atom must be "present" in the original source form, and
1217 ;;; present in all intervening actual source forms.
1218 (defun note-block-deletion (block)
1219 (let ((home (block-home-lambda block)))
1220 (unless (eq (functional-kind home) :deleted)
1221 (do-nodes (node nil block)
1222 (let* ((path (node-source-path node))
1223 (first (first path)))
1224 (when (or (eq first 'original-source-start)
1226 (or (not (symbolp first))
1227 (let ((pkg (symbol-package first)))
1229 (not (eq pkg (symbol-package :end))))))
1230 (not (member first *deletion-ignored-objects*))
1231 (not (typep first '(or fixnum character)))
1233 (present-in-form first x 0))
1234 (source-path-forms path))
1235 (present-in-form first (find-original-source path)
1237 (unless (return-p node)
1238 (let ((*compiler-error-context* node))
1239 (compiler-notify 'code-deletion-note
1240 :format-control "deleting unreachable code"
1241 :format-arguments nil)))
1245 ;;; Delete a node from a block, deleting the block if there are no
1246 ;;; nodes left. We remove the node from the uses of its LVAR.
1248 ;;; If the node is the last node, there must be exactly one successor.
1249 ;;; We link all of our precedessors to the successor and unlink the
1250 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1251 ;;; left, and the block is a successor of itself, then we replace the
1252 ;;; only node with a degenerate exit node. This provides a way to
1253 ;;; represent the bodyless infinite loop, given the prohibition on
1254 ;;; empty blocks in IR1.
1255 (defun unlink-node (node)
1256 (declare (type node node))
1257 (when (valued-node-p node)
1258 (delete-lvar-use node))
1260 (let* ((ctran (node-next node))
1261 (next (and ctran (ctran-next ctran)))
1262 (prev (node-prev node))
1263 (block (ctran-block prev))
1264 (prev-kind (ctran-kind prev))
1265 (last (block-last block)))
1267 (setf (block-type-asserted block) t)
1268 (setf (block-test-modified block) t)
1270 (cond ((or (eq prev-kind :inside-block)
1271 (and (eq prev-kind :block-start)
1272 (not (eq node last))))
1273 (cond ((eq node last)
1274 (setf (block-last block) (ctran-use prev))
1275 (setf (node-next (ctran-use prev)) nil))
1277 (setf (ctran-next prev) next)
1278 (setf (node-prev next) prev)
1279 (when (if-p next) ; AOP wanted
1280 (reoptimize-lvar (if-test next)))))
1281 (setf (node-prev node) nil)
1284 (aver (eq prev-kind :block-start))
1285 (aver (eq node last))
1286 (let* ((succ (block-succ block))
1287 (next (first succ)))
1288 (aver (singleton-p succ))
1290 ((eq block (first succ))
1291 (with-ir1-environment-from-node node
1292 (let ((exit (make-exit)))
1293 (setf (ctran-next prev) nil)
1294 (link-node-to-previous-ctran exit prev)
1295 (setf (block-last block) exit)))
1296 (setf (node-prev node) nil)
1299 (aver (eq (block-start-cleanup block)
1300 (block-end-cleanup block)))
1301 (unlink-blocks block next)
1302 (dolist (pred (block-pred block))
1303 (change-block-successor pred block next))
1304 (when (block-delete-p block)
1305 (let ((component (block-component block)))
1306 (setf (component-delete-blocks component)
1307 (delq block (component-delete-blocks component)))))
1308 (remove-from-dfo block)
1309 (setf (block-delete-p block) t)
1310 (setf (node-prev node) nil)
1313 ;;; Return true if NODE has been deleted, false if it is still a valid
1315 (defun node-deleted (node)
1316 (declare (type node node))
1317 (let ((prev (node-prev node)))
1319 (let ((block (ctran-block prev)))
1320 (and (block-component block)
1321 (not (block-delete-p block))))))))
1323 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1324 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1325 ;;; triggered by deletion.
1326 (defun delete-component (component)
1327 (declare (type component component))
1328 (aver (null (component-new-functionals component)))
1329 (setf (component-kind component) :deleted)
1330 (do-blocks (block component)
1331 (delete-block-lazily block))
1332 (dolist (fun (component-lambdas component))
1333 (unless (eq (functional-kind fun) :deleted)
1334 (setf (functional-kind fun) nil)
1335 (setf (functional-entry-fun fun) nil)
1336 (setf (leaf-refs fun) nil)
1337 (delete-functional fun)))
1338 (clean-component component)
1341 ;;; Remove all pending blocks to be deleted. Return the nearest live
1342 ;;; block after or equal to BLOCK.
1343 (defun clean-component (component &optional block)
1344 (loop while (component-delete-blocks component)
1345 ;; actual deletion of a block may queue new blocks
1346 do (let ((current (pop (component-delete-blocks component))))
1347 (when (eq block current)
1348 (setq block (block-next block)))
1349 (delete-block current)))
1352 ;;; Convert code of the form
1353 ;;; (FOO ... (FUN ...) ...)
1355 ;;; (FOO ... ... ...).
1356 ;;; In other words, replace the function combination FUN by its
1357 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1358 ;;; to blow out of whatever transform called this. Note, as the number
1359 ;;; of arguments changes, the transform must be prepared to return a
1360 ;;; lambda with a new lambda-list with the correct number of
1362 (defun extract-fun-args (lvar fun num-args)
1364 "If LVAR is a call to FUN with NUM-ARGS args, change those arguments
1365 to feed directly to the LVAR-DEST of LVAR, which must be a
1367 (declare (type lvar lvar)
1369 (type index num-args))
1370 (let ((outside (lvar-dest lvar))
1371 (inside (lvar-uses lvar)))
1372 (aver (combination-p outside))
1373 (unless (combination-p inside)
1374 (give-up-ir1-transform))
1375 (let ((inside-fun (combination-fun inside)))
1376 (unless (eq (lvar-fun-name inside-fun) fun)
1377 (give-up-ir1-transform))
1378 (let ((inside-args (combination-args inside)))
1379 (unless (= (length inside-args) num-args)
1380 (give-up-ir1-transform))
1381 (let* ((outside-args (combination-args outside))
1382 (arg-position (position lvar outside-args))
1383 (before-args (subseq outside-args 0 arg-position))
1384 (after-args (subseq outside-args (1+ arg-position))))
1385 (dolist (arg inside-args)
1386 (setf (lvar-dest arg) outside)
1387 (flush-lvar-externally-checkable-type arg))
1388 (setf (combination-args inside) nil)
1389 (setf (combination-args outside)
1390 (append before-args inside-args after-args))
1391 (change-ref-leaf (lvar-uses inside-fun)
1392 (find-free-fun 'list "???"))
1393 (setf (combination-fun-info inside) (info :function :info 'list)
1394 (combination-kind inside) :known)
1395 (setf (node-derived-type inside) *wild-type*)
1399 (defun flush-combination (combination)
1400 (declare (type combination combination))
1401 (flush-dest (combination-fun combination))
1402 (dolist (arg (combination-args combination))
1404 (unlink-node combination)
1410 ;;; Change the LEAF that a REF refers to.
1411 (defun change-ref-leaf (ref leaf)
1412 (declare (type ref ref) (type leaf leaf))
1413 (unless (eq (ref-leaf ref) leaf)
1414 (push ref (leaf-refs leaf))
1416 (setf (ref-leaf ref) leaf)
1417 (setf (leaf-ever-used leaf) t)
1418 (let* ((ltype (leaf-type leaf))
1419 (vltype (make-single-value-type ltype)))
1420 (if (let* ((lvar (node-lvar ref))
1421 (dest (and lvar (lvar-dest lvar))))
1422 (and (basic-combination-p dest)
1423 (eq lvar (basic-combination-fun dest))
1424 (csubtypep ltype (specifier-type 'function))))
1425 (setf (node-derived-type ref) vltype)
1426 (derive-node-type ref vltype)))
1427 (reoptimize-lvar (node-lvar ref)))
1430 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1431 (defun substitute-leaf (new-leaf old-leaf)
1432 (declare (type leaf new-leaf old-leaf))
1433 (dolist (ref (leaf-refs old-leaf))
1434 (change-ref-leaf ref new-leaf))
1437 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1438 ;;; whether to substitute
1439 (defun substitute-leaf-if (test new-leaf old-leaf)
1440 (declare (type leaf new-leaf old-leaf) (type function test))
1441 (dolist (ref (leaf-refs old-leaf))
1442 (when (funcall test ref)
1443 (change-ref-leaf ref new-leaf)))
1446 ;;; Return a LEAF which represents the specified constant object. If
1447 ;;; the object is not in *CONSTANTS*, then we create a new constant
1448 ;;; LEAF and enter it.
1449 (defun find-constant (object)
1451 ;; FIXME: What is the significance of this test? ("things
1452 ;; that are worth uniquifying"?)
1453 '(or symbol number character instance))
1454 (or (gethash object *constants*)
1455 (setf (gethash object *constants*)
1456 (make-constant :value object
1457 :%source-name '.anonymous.
1458 :type (ctype-of object)
1459 :where-from :defined)))
1460 (make-constant :value object
1461 :%source-name '.anonymous.
1462 :type (ctype-of object)
1463 :where-from :defined)))
1465 ;;; Return true if VAR would have to be closed over if environment
1466 ;;; analysis ran now (i.e. if there are any uses that have a different
1467 ;;; home lambda than VAR's home.)
1468 (defun closure-var-p (var)
1469 (declare (type lambda-var var))
1470 (let ((home (lambda-var-home var)))
1471 (cond ((eq (functional-kind home) :deleted)
1473 (t (let ((home (lambda-home home)))
1476 :key #'node-home-lambda
1478 (or (frob (leaf-refs var))
1479 (frob (basic-var-sets var)))))))))
1481 ;;; If there is a non-local exit noted in ENTRY's environment that
1482 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1483 (defun find-nlx-info (exit)
1484 (declare (type exit exit))
1485 (let ((entry (exit-entry exit)))
1486 (dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
1487 (when (eq (nlx-info-exit nlx) exit)
1490 ;;;; functional hackery
1492 (declaim (ftype (sfunction (functional) clambda) main-entry))
1493 (defun main-entry (functional)
1494 (etypecase functional
1495 (clambda functional)
1497 (optional-dispatch-main-entry functional))))
1499 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1500 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1501 ;;; optional with null default and no SUPPLIED-P. There must be a
1502 ;;; &REST arg with no references.
1503 (declaim (ftype (sfunction (functional) boolean) looks-like-an-mv-bind))
1504 (defun looks-like-an-mv-bind (functional)
1505 (and (optional-dispatch-p functional)
1506 (do ((arg (optional-dispatch-arglist functional) (cdr arg)))
1508 (let ((info (lambda-var-arg-info (car arg))))
1509 (unless info (return nil))
1510 (case (arg-info-kind info)
1512 (when (or (arg-info-supplied-p info) (arg-info-default info))
1515 (return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
1519 ;;; Return true if function is an external entry point. This is true
1520 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1521 ;;; (:TOPLEVEL kind.)
1523 (declare (type functional fun))
1524 (not (null (member (functional-kind fun) '(:external :toplevel)))))
1526 ;;; If LVAR's only use is a non-notinline global function reference,
1527 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1528 ;;; is true, then we don't care if the leaf is NOTINLINE.
1529 (defun lvar-fun-name (lvar &optional notinline-ok)
1530 (declare (type lvar lvar))
1531 (let ((use (lvar-uses lvar)))
1533 (let ((leaf (ref-leaf use)))
1534 (if (and (global-var-p leaf)
1535 (eq (global-var-kind leaf) :global-function)
1536 (or (not (defined-fun-p leaf))
1537 (not (eq (defined-fun-inlinep leaf) :notinline))
1539 (leaf-source-name leaf)
1543 ;;; Return the source name of a combination. (This is an idiom
1544 ;;; which was used in CMU CL. I gather it always works. -- WHN)
1545 (defun combination-fun-source-name (combination)
1546 (let ((ref (lvar-uses (combination-fun combination))))
1547 (leaf-source-name (ref-leaf ref))))
1549 ;;; Return the COMBINATION node that is the call to the LET FUN.
1550 (defun let-combination (fun)
1551 (declare (type clambda fun))
1552 (aver (functional-letlike-p fun))
1553 (lvar-dest (node-lvar (first (leaf-refs fun)))))
1555 ;;; Return the initial value lvar for a LET variable, or NIL if there
1557 (defun let-var-initial-value (var)
1558 (declare (type lambda-var var))
1559 (let ((fun (lambda-var-home var)))
1560 (elt (combination-args (let-combination fun))
1561 (position-or-lose var (lambda-vars fun)))))
1563 ;;; Return the LAMBDA that is called by the local CALL.
1564 (defun combination-lambda (call)
1565 (declare (type basic-combination call))
1566 (aver (eq (basic-combination-kind call) :local))
1567 (ref-leaf (lvar-uses (basic-combination-fun call))))
1569 (defvar *inline-expansion-limit* 200
1571 "an upper limit on the number of inline function calls that will be expanded
1572 in any given code object (single function or block compilation)")
1574 ;;; Check whether NODE's component has exceeded its inline expansion
1575 ;;; limit, and warn if so, returning NIL.
1576 (defun inline-expansion-ok (node)
1577 (let ((expanded (incf (component-inline-expansions
1579 (node-block node))))))
1580 (cond ((> expanded *inline-expansion-limit*) nil)
1581 ((= expanded *inline-expansion-limit*)
1582 ;; FIXME: If the objective is to stop the recursive
1583 ;; expansion of inline functions, wouldn't it be more
1584 ;; correct to look back through surrounding expansions
1585 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1586 ;; possibly stored elsewhere too) and suppress expansion
1587 ;; and print this warning when the function being proposed
1588 ;; for inline expansion is found there? (I don't like the
1589 ;; arbitrary numerical limit in principle, and I think
1590 ;; it'll be a nuisance in practice if we ever want the
1591 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1592 ;; arbitrarily huge blocks of code. -- WHN)
1593 (let ((*compiler-error-context* node))
1594 (compiler-notify "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1595 probably trying to~% ~
1596 inline a recursive function."
1597 *inline-expansion-limit*))
1601 ;;; Make sure that FUNCTIONAL is not let-converted or deleted.
1602 (defun assure-functional-live-p (functional)
1603 (declare (type functional functional))
1605 ;; looks LET-converted
1606 (functional-somewhat-letlike-p functional)
1607 ;; It's possible for a LET-converted function to end up
1608 ;; deleted later. In that case, for the purposes of this
1609 ;; analysis, it is LET-converted: LET-converted functionals
1610 ;; are too badly trashed to expand them inline, and deleted
1611 ;; LET-converted functionals are even worse.
1612 (memq (functional-kind functional) '(:deleted :zombie))))
1613 (throw 'locall-already-let-converted functional)))
1615 (defun call-full-like-p (call)
1616 (declare (type combination call))
1617 (let ((kind (basic-combination-kind call)))
1619 (and (eq kind :known)
1620 (let ((info (basic-combination-fun-info call)))
1622 (not (fun-info-ir2-convert info))
1623 (dolist (template (fun-info-templates info) t)
1624 (when (eq (template-ltn-policy template) :fast-safe)
1625 (multiple-value-bind (val win)
1626 (valid-fun-use call (template-type template))
1627 (when (or val (not win)) (return nil)))))))))))
1631 ;;; Apply a function to some arguments, returning a list of the values
1632 ;;; resulting of the evaluation. If an error is signalled during the
1633 ;;; application, then we produce a warning message using WARN-FUN and
1634 ;;; return NIL as our second value to indicate this. NODE is used as
1635 ;;; the error context for any error message, and CONTEXT is a string
1636 ;;; that is spliced into the warning.
1637 (declaim (ftype (sfunction ((or symbol function) list node function string)
1638 (values list boolean))
1640 (defun careful-call (function args node warn-fun context)
1642 (multiple-value-list
1643 (handler-case (apply function args)
1645 (let ((*compiler-error-context* node))
1646 (funcall warn-fun "Lisp error during ~A:~%~A" context condition)
1647 (return-from careful-call (values nil nil))))))
1650 ;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
1653 ((deffrob (basic careful compiler transform)
1655 (defun ,careful (specifier)
1656 (handler-case (,basic specifier)
1657 (sb!kernel::arg-count-error (condition)
1658 (values nil (list (format nil "~A" condition))))
1659 (simple-error (condition)
1660 (values nil (list* (simple-condition-format-control condition)
1661 (simple-condition-format-arguments condition))))))
1662 (defun ,compiler (specifier)
1663 (multiple-value-bind (type error-args) (,careful specifier)
1665 (apply #'compiler-error error-args))))
1666 (defun ,transform (specifier)
1667 (multiple-value-bind (type error-args) (,careful specifier)
1669 (apply #'give-up-ir1-transform
1671 (deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type)
1672 (deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type))
1675 ;;;; utilities used at run-time for parsing &KEY args in IR1
1677 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1678 ;;; the lvar for the value of the &KEY argument KEY in the list of
1679 ;;; lvars ARGS. It returns the lvar if the keyword is present, or NIL
1680 ;;; otherwise. The legality and constantness of the keywords should
1681 ;;; already have been checked.
1682 (declaim (ftype (sfunction (list keyword) (or lvar null))
1684 (defun find-keyword-lvar (args key)
1685 (do ((arg args (cddr arg)))
1687 (when (eq (lvar-value (first arg)) key)
1688 (return (second arg)))))
1690 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1691 ;;; verify that alternating lvars in ARGS are constant and that there
1692 ;;; is an even number of args.
1693 (declaim (ftype (sfunction (list) boolean) check-key-args-constant))
1694 (defun check-key-args-constant (args)
1695 (do ((arg args (cddr arg)))
1697 (unless (and (rest arg)
1698 (constant-lvar-p (first arg)))
1701 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1702 ;;; verify that the list of lvars ARGS is a well-formed &KEY arglist
1703 ;;; and that only keywords present in the list KEYS are supplied.
1704 (declaim (ftype (sfunction (list list) boolean) check-transform-keys))
1705 (defun check-transform-keys (args keys)
1706 (and (check-key-args-constant args)
1707 (do ((arg args (cddr arg)))
1709 (unless (member (lvar-value (first arg)) keys)
1714 ;;; Called by the expansion of the EVENT macro.
1715 (declaim (ftype (sfunction (event-info (or node null)) *) %event))
1716 (defun %event (info node)
1717 (incf (event-info-count info))
1718 (when (and (>= (event-info-level info) *event-note-threshold*)
1719 (policy (or node *lexenv*)
1720 (= inhibit-warnings 0)))
1721 (let ((*compiler-error-context* node))
1722 (compiler-notify (event-info-description info))))
1724 (let ((action (event-info-action info)))
1725 (when action (funcall action node))))
1728 (defun make-cast (value type policy)
1729 (declare (type lvar value)
1731 (type policy policy))
1732 (%make-cast :asserted-type type
1733 :type-to-check (maybe-weaken-check type policy)
1735 :derived-type (coerce-to-values type)))
1737 (defun cast-type-check (cast)
1738 (declare (type cast cast))
1739 (when (cast-reoptimize cast)
1740 (ir1-optimize-cast cast t))
1741 (cast-%type-check cast))
1743 (defun note-single-valuified-lvar (lvar)
1744 (declare (type (or lvar null) lvar))
1746 (let ((use (lvar-uses lvar)))
1748 (let ((leaf (ref-leaf use)))
1749 (when (and (lambda-var-p leaf)
1750 (null (rest (leaf-refs leaf))))
1751 (reoptimize-lambda-var leaf))))
1752 ((or (listp use) (combination-p use))
1753 (do-uses (node lvar)
1754 (setf (node-reoptimize node) t)
1755 (setf (block-reoptimize (node-block node)) t)
1756 (setf (component-reoptimize (node-component node)) t)))))))