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)
67 (declare (type lvar lvar
))
68 (let ((use (lvar-uses lvar
)))
70 (plu (cast-value use
))
74 ;;; Update lvar use information so that NODE is no longer a use of its
77 ;;; Note: if you call this function, you may have to do a
78 ;;; REOPTIMIZE-LVAR to inform IR1 optimization that something has
80 (declaim (ftype (sfunction (node) (values))
83 ;;; Just delete NODE from its LVAR uses; LVAR is preserved so it may
84 ;;; be given a new use.
85 (defun %delete-lvar-use
(node)
86 (let ((lvar (node-lvar node
)))
88 (if (listp (lvar-uses lvar
))
89 (let ((new-uses (delq node
(lvar-uses lvar
))))
90 (setf (lvar-uses lvar
)
91 (if (singleton-p new-uses
)
94 (setf (lvar-uses lvar
) nil
))
95 (setf (node-lvar node
) nil
)))
97 ;;; Delete NODE from its LVAR uses; if LVAR has no other uses, delete
98 ;;; its DEST's block, which must be unreachable.
99 (defun delete-lvar-use (node)
100 (let ((lvar (node-lvar node
)))
102 (%delete-lvar-use node
)
103 (if (null (lvar-uses lvar
))
104 (binding* ((dest (lvar-dest lvar
) :exit-if-null
)
105 (() (not (node-deleted dest
)) :exit-if-null
)
106 (block (node-block dest
)))
107 (mark-for-deletion block
))
108 (reoptimize-lvar lvar
))))
111 ;;; Update lvar use information so that NODE uses LVAR.
113 ;;; Note: if you call this function, you may have to do a
114 ;;; REOPTIMIZE-LVAR to inform IR1 optimization that something has
116 (declaim (ftype (sfunction (node (or lvar null
)) (values)) add-lvar-use
))
117 (defun add-lvar-use (node lvar
)
118 (aver (not (node-lvar node
)))
120 (let ((uses (lvar-uses lvar
)))
121 (setf (lvar-uses lvar
)
128 (setf (node-lvar node
) lvar
)))
132 ;;; Return true if LVAR destination is executed immediately after
133 ;;; NODE. Cleanups are ignored.
134 (defun immediately-used-p (lvar node
)
135 (declare (type lvar lvar
) (type node node
))
136 (aver (eq (node-lvar node
) lvar
))
137 (let ((dest (lvar-dest lvar
)))
138 (acond ((node-next node
)
139 (eq (ctran-next it
) dest
))
140 (t (eq (block-start (first (block-succ (node-block node
))))
141 (node-prev dest
))))))
143 ;;;; lvar substitution
145 ;;; In OLD's DEST, replace OLD with NEW. NEW's DEST must initially be
146 ;;; NIL. We do not flush OLD's DEST.
147 (defun substitute-lvar (new old
)
148 (declare (type lvar old new
))
149 (aver (not (lvar-dest new
)))
150 (let ((dest (lvar-dest old
)))
153 (cif (setf (if-test dest
) new
))
154 (cset (setf (set-value dest
) new
))
155 (creturn (setf (return-result dest
) new
))
156 (exit (setf (exit-value dest
) new
))
158 (if (eq old
(basic-combination-fun dest
))
159 (setf (basic-combination-fun dest
) new
)
160 (setf (basic-combination-args dest
)
161 (nsubst new old
(basic-combination-args dest
)))))
162 (cast (setf (cast-value dest
) new
)))
164 (setf (lvar-dest old
) nil
)
165 (setf (lvar-dest new
) dest
)
166 (flush-lvar-externally-checkable-type new
))
169 ;;; Replace all uses of OLD with uses of NEW, where NEW has an
170 ;;; arbitary number of uses. NEW is supposed to be "later" than OLD.
171 (defun substitute-lvar-uses (new old propagate-dx
)
172 (declare (type lvar old
)
173 (type (or lvar null
) new
)
174 (type boolean propagate-dx
))
178 (%delete-lvar-use node
)
179 (add-lvar-use node new
))
180 (reoptimize-lvar new
)
181 (awhen (and propagate-dx
(lvar-dynamic-extent old
))
182 (setf (lvar-dynamic-extent old
) nil
)
183 (unless (lvar-dynamic-extent new
)
184 (setf (lvar-dynamic-extent new
) it
)
185 (setf (cleanup-info it
) (substitute new old
(cleanup-info it
)))))
186 (when (lvar-dynamic-extent new
)
188 (node-ends-block node
))))
189 (t (flush-dest old
)))
193 ;;;; block starting/creation
195 ;;; Return the block that CTRAN is the start of, making a block if
196 ;;; necessary. This function is called by IR1 translators which may
197 ;;; cause a CTRAN to be used more than once. Every CTRAN which may be
198 ;;; used more than once must start a block by the time that anyone
199 ;;; does a USE-CTRAN on it.
201 ;;; We also throw the block into the next/prev list for the
202 ;;; *CURRENT-COMPONENT* so that we keep track of which blocks we have
204 (defun ctran-starts-block (ctran)
205 (declare (type ctran ctran
))
206 (ecase (ctran-kind ctran
)
208 (aver (not (ctran-block ctran
)))
209 (let* ((next (component-last-block *current-component
*))
210 (prev (block-prev next
))
211 (new-block (make-block ctran
)))
212 (setf (block-next new-block
) next
213 (block-prev new-block
) prev
214 (block-prev next
) new-block
215 (block-next prev
) new-block
216 (ctran-block ctran
) new-block
217 (ctran-kind ctran
) :block-start
)
218 (aver (not (ctran-use ctran
)))
221 (ctran-block ctran
))))
223 ;;; Ensure that CTRAN is the start of a block so that the use set can
224 ;;; be freely manipulated.
225 (defun ensure-block-start (ctran)
226 (declare (type ctran ctran
))
227 (let ((kind (ctran-kind ctran
)))
231 (setf (ctran-block ctran
)
232 (make-block-key :start ctran
))
233 (setf (ctran-kind ctran
) :block-start
))
235 (node-ends-block (ctran-use ctran
)))))
238 ;;; CTRAN must be the last ctran in an incomplete block; finish the
239 ;;; block and start a new one if necessary.
240 (defun start-block (ctran)
241 (declare (type ctran ctran
))
242 (aver (not (ctran-next ctran
)))
243 (ecase (ctran-kind ctran
)
245 (let ((block (ctran-block ctran
))
246 (node (ctran-use ctran
)))
247 (aver (not (block-last block
)))
249 (setf (block-last block
) node
)
250 (setf (node-next node
) nil
)
251 (setf (ctran-use ctran
) nil
)
252 (setf (ctran-kind ctran
) :unused
)
253 (setf (ctran-block ctran
) nil
)
254 (link-blocks block
(ctran-starts-block ctran
))))
259 ;;; Filter values of LVAR through FORM, which must be an ordinary/mv
260 ;;; call. First argument must be 'DUMMY, which will be replaced with
261 ;;; LVAR. In case of an ordinary call the function should not have
262 ;;; return type NIL. We create a new "filtered" lvar.
264 ;;; TODO: remove preconditions.
265 (defun filter-lvar (lvar form
)
266 (declare (type lvar lvar
) (type list form
))
267 (let* ((dest (lvar-dest lvar
))
268 (ctran (node-prev dest
)))
269 (with-ir1-environment-from-node dest
271 (ensure-block-start ctran
)
272 (let* ((old-block (ctran-block ctran
))
273 (new-start (make-ctran))
274 (filtered-lvar (make-lvar))
275 (new-block (ctran-starts-block new-start
)))
277 ;; Splice in the new block before DEST, giving the new block
278 ;; all of DEST's predecessors.
279 (dolist (block (block-pred old-block
))
280 (change-block-successor block old-block new-block
))
282 (ir1-convert new-start ctran filtered-lvar form
)
284 ;; KLUDGE: Comments at the head of this function in CMU CL
285 ;; said that somewhere in here we
286 ;; Set the new block's start and end cleanups to the *start*
287 ;; cleanup of PREV's block. This overrides the incorrect
288 ;; default from WITH-IR1-ENVIRONMENT-FROM-NODE.
289 ;; Unfortunately I can't find any code which corresponds to this.
290 ;; Perhaps it was a stale comment? Or perhaps I just don't
291 ;; understand.. -- WHN 19990521
293 ;; Replace 'DUMMY with the LVAR. (We can find 'DUMMY because
294 ;; no LET conversion has been done yet.) The [mv-]combination
295 ;; code from the call in the form will be the use of the new
296 ;; check lvar. We substitute for the first argument of
298 (let* ((node (lvar-use filtered-lvar
))
299 (args (basic-combination-args node
))
300 (victim (first args
)))
301 (aver (eq (constant-value (ref-leaf (lvar-use victim
)))
304 (substitute-lvar filtered-lvar lvar
)
305 (substitute-lvar lvar victim
)
308 ;; Invoking local call analysis converts this call to a LET.
309 (locall-analyze-component *current-component
*))))
312 ;;; Delete NODE and VALUE. It may result in some calls becoming tail.
313 (defun delete-filter (node lvar value
)
314 (aver (eq (lvar-dest value
) node
))
315 (aver (eq (node-lvar node
) lvar
))
316 (cond (lvar (collect ((merges))
317 (when (return-p (lvar-dest lvar
))
319 (when (and (basic-combination-p use
)
320 (eq (basic-combination-kind use
) :local
))
322 (substitute-lvar-uses lvar value
323 (and lvar
(eq (lvar-uses lvar
) node
)))
324 (%delete-lvar-use node
)
327 (dolist (merge (merges))
328 (merge-tail-sets merge
)))))
329 (t (flush-dest value
)
330 (unlink-node node
))))
332 ;;; Make a CAST and insert it into IR1 before node NEXT.
333 (defun insert-cast-before (next lvar type policy
)
334 (declare (type node next
) (type lvar lvar
) (type ctype type
))
335 (with-ir1-environment-from-node next
336 (let* ((ctran (node-prev next
))
337 (cast (make-cast lvar type policy
))
338 (internal-ctran (make-ctran)))
339 (setf (ctran-next ctran
) cast
340 (node-prev cast
) ctran
)
341 (use-ctran cast internal-ctran
)
342 (link-node-to-previous-ctran next internal-ctran
)
343 (setf (lvar-dest lvar
) cast
)
344 (reoptimize-lvar lvar
)
345 (when (return-p next
)
346 (node-ends-block cast
))
347 (setf (block-attributep (block-flags (node-block cast
))
348 type-check type-asserted
)
352 ;;;; miscellaneous shorthand functions
354 ;;; Return the home (i.e. enclosing non-LET) CLAMBDA for NODE. Since
355 ;;; the LEXENV-LAMBDA may be deleted, we must chain up the
356 ;;; LAMBDA-CALL-LEXENV thread until we find a CLAMBDA that isn't
357 ;;; deleted, and then return its home.
358 (defun node-home-lambda (node)
359 (declare (type node node
))
360 (do ((fun (lexenv-lambda (node-lexenv node
))
361 (lexenv-lambda (lambda-call-lexenv fun
))))
362 ((not (memq (functional-kind fun
) '(:deleted
:zombie
)))
364 (when (eq (lambda-home fun
) fun
)
367 #!-sb-fluid
(declaim (inline node-block
))
368 (defun node-block (node)
369 (ctran-block (node-prev node
)))
370 (declaim (ftype (sfunction (node) component
) node-component
))
371 (defun node-component (node)
372 (block-component (node-block node
)))
373 (declaim (ftype (sfunction (node) physenv
) node-physenv
))
374 (defun node-physenv (node)
375 (lambda-physenv (node-home-lambda node
)))
376 #!-sb-fluid
(declaim (inline node-dest
))
377 (defun node-dest (node)
378 (awhen (node-lvar node
) (lvar-dest it
)))
380 #!-sb-fluid
(declaim (inline node-stack-allocate-p
))
381 (defun node-stack-allocate-p (node)
382 (awhen (node-lvar node
)
383 (lvar-dynamic-extent it
)))
385 (declaim (inline block-to-be-deleted-p
))
386 (defun block-to-be-deleted-p (block)
387 (or (block-delete-p block
)
388 (eq (functional-kind (block-home-lambda block
)) :deleted
)))
390 ;;; Checks whether NODE is in a block to be deleted
391 (declaim (inline node-to-be-deleted-p
))
392 (defun node-to-be-deleted-p (node)
393 (block-to-be-deleted-p (node-block node
)))
395 (declaim (ftype (sfunction (clambda) cblock
) lambda-block
))
396 (defun lambda-block (clambda)
397 (node-block (lambda-bind clambda
)))
398 (declaim (ftype (sfunction (clambda) component
) lambda-component
))
399 (defun lambda-component (clambda)
400 (block-component (lambda-block clambda
)))
402 (declaim (ftype (sfunction (cblock) node
) block-start-node
))
403 (defun block-start-node (block)
404 (ctran-next (block-start block
)))
406 ;;; Return the enclosing cleanup for environment of the first or last
408 (defun block-start-cleanup (block)
409 (node-enclosing-cleanup (block-start-node block
)))
410 (defun block-end-cleanup (block)
411 (node-enclosing-cleanup (block-last block
)))
413 ;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
414 ;;; if there is none.
416 ;;; There can legitimately be no home lambda in dead code early in the
417 ;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
418 ;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
419 ;;; where the block is just a placeholder during parsing and doesn't
420 ;;; actually correspond to code which will be written anywhere.
421 (declaim (ftype (sfunction (cblock) (or clambda null
)) block-home-lambda-or-null
))
422 (defun block-home-lambda-or-null (block)
423 (if (node-p (block-last block
))
424 ;; This is the old CMU CL way of doing it.
425 (node-home-lambda (block-last block
))
426 ;; Now that SBCL uses this operation more aggressively than CMU
427 ;; CL did, the old CMU CL way of doing it can fail in two ways.
428 ;; 1. It can fail in a few cases even when a meaningful home
429 ;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
431 ;; 2. It can fail when converting a form which is born orphaned
432 ;; so that it never had a meaningful home lambda, e.g. a form
433 ;; which follows a RETURN-FROM or GO form.
434 (let ((pred-list (block-pred block
)))
435 ;; To deal with case 1, we reason that
436 ;; previous-in-target-execution-order blocks should be in the
437 ;; same lambda, and that they seem in practice to be
438 ;; previous-in-compilation-order blocks too, so we look back
439 ;; to find one which is sufficiently initialized to tell us
440 ;; what the home lambda is.
442 ;; We could get fancy about this, flooding through the
443 ;; graph of all the previous blocks, but in practice it
444 ;; seems to work just to grab the first previous block and
446 (node-home-lambda (block-last (first pred-list
)))
447 ;; In case 2, we end up with an empty PRED-LIST and
448 ;; have to punt: There's no home lambda.
451 ;;; Return the non-LET LAMBDA that holds BLOCK's code.
452 (declaim (ftype (sfunction (cblock) clambda
) block-home-lambda
))
453 (defun block-home-lambda (block)
454 (block-home-lambda-or-null block
))
456 ;;; Return the IR1 physical environment for BLOCK.
457 (declaim (ftype (sfunction (cblock) physenv
) block-physenv
))
458 (defun block-physenv (block)
459 (lambda-physenv (block-home-lambda block
)))
461 ;;; Return the Top Level Form number of PATH, i.e. the ordinal number
462 ;;; of its original source's top level form in its compilation unit.
463 (defun source-path-tlf-number (path)
464 (declare (list path
))
467 ;;; Return the (reversed) list for the PATH in the original source
468 ;;; (with the Top Level Form number last).
469 (defun source-path-original-source (path)
470 (declare (list path
) (inline member
))
471 (cddr (member 'original-source-start path
:test
#'eq
)))
473 ;;; Return the Form Number of PATH's original source inside the Top
474 ;;; Level Form that contains it. This is determined by the order that
475 ;;; we walk the subforms of the top level source form.
476 (defun source-path-form-number (path)
477 (declare (list path
) (inline member
))
478 (cadr (member 'original-source-start path
:test
#'eq
)))
480 ;;; Return a list of all the enclosing forms not in the original
481 ;;; source that converted to get to this form, with the immediate
482 ;;; source for node at the start of the list.
483 (defun source-path-forms (path)
484 (subseq path
0 (position 'original-source-start path
)))
486 ;;; Return the innermost source form for NODE.
487 (defun node-source-form (node)
488 (declare (type node node
))
489 (let* ((path (node-source-path node
))
490 (forms (source-path-forms path
)))
493 (values (find-original-source path
)))))
495 ;;; Return NODE-SOURCE-FORM, T if lvar has a single use, otherwise
497 (defun lvar-source (lvar)
498 (let ((use (lvar-uses lvar
)))
501 (values (node-source-form use
) t
))))
503 ;;; Return the unique node, delivering a value to LVAR.
504 #!-sb-fluid
(declaim (inline lvar-use
))
505 (defun lvar-use (lvar)
506 (the (not list
) (lvar-uses lvar
)))
508 #!-sb-fluid
(declaim (inline lvar-has-single-use-p
))
509 (defun lvar-has-single-use-p (lvar)
510 (typep (lvar-uses lvar
) '(not list
)))
512 ;;; Return the LAMBDA that is CTRAN's home, or NIL if there is none.
513 (declaim (ftype (sfunction (ctran) (or clambda null
))
514 ctran-home-lambda-or-null
))
515 (defun ctran-home-lambda-or-null (ctran)
516 ;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
517 ;; implementation might not be quite right, or might be uglier than
518 ;; necessary. It appears that the original Python never found a need
519 ;; to do this operation. The obvious things based on
520 ;; NODE-HOME-LAMBDA of CTRAN-USE usually work; then if that fails,
521 ;; BLOCK-HOME-LAMBDA of CTRAN-BLOCK works, given that we
522 ;; generalize it enough to grovel harder when the simple CMU CL
523 ;; approach fails, and furthermore realize that in some exceptional
524 ;; cases it might return NIL. -- WHN 2001-12-04
525 (cond ((ctran-use ctran
)
526 (node-home-lambda (ctran-use ctran
)))
528 (block-home-lambda-or-null (ctran-block ctran
)))
530 (bug "confused about home lambda for ~S" ctran
))))
532 ;;; Return the LAMBDA that is CTRAN's home.
533 (declaim (ftype (sfunction (ctran) clambda
) ctran-home-lambda
))
534 (defun ctran-home-lambda (ctran)
535 (ctran-home-lambda-or-null ctran
))
537 (declaim (inline cast-single-value-p
))
538 (defun cast-single-value-p (cast)
539 (not (values-type-p (cast-asserted-type cast
))))
541 #!-sb-fluid
(declaim (inline lvar-single-value-p
))
542 (defun lvar-single-value-p (lvar)
544 (let ((dest (lvar-dest lvar
)))
549 (eq (basic-combination-fun dest
) lvar
))
552 (declare (notinline lvar-single-value-p
))
553 (and (cast-single-value-p dest
)
554 (lvar-single-value-p (node-lvar dest
)))))
558 (defun principal-lvar-end (lvar)
559 (loop for prev
= lvar then
(node-lvar dest
)
560 for dest
= (and prev
(lvar-dest prev
))
562 finally
(return (values dest prev
))))
564 (defun principal-lvar-single-valuify (lvar)
565 (loop for prev
= lvar then
(node-lvar dest
)
566 for dest
= (and prev
(lvar-dest prev
))
568 do
(setf (node-derived-type dest
)
569 (make-short-values-type (list (single-value-type
570 (node-derived-type dest
)))))
571 (reoptimize-lvar prev
)))
573 ;;; Return a new LEXENV just like DEFAULT except for the specified
574 ;;; slot values. Values for the alist slots are NCONCed to the
575 ;;; beginning of the current value, rather than replacing it entirely.
576 (defun make-lexenv (&key
(default *lexenv
*)
577 funs vars blocks tags
579 (lambda (lexenv-lambda default
))
580 (cleanup (lexenv-cleanup default
))
581 (handled-conditions (lexenv-handled-conditions default
))
582 (disabled-package-locks
583 (lexenv-disabled-package-locks default
))
584 (policy (lexenv-policy default
)))
585 (macrolet ((frob (var slot
)
586 `(let ((old (,slot default
)))
590 (internal-make-lexenv
591 (frob funs lexenv-funs
)
592 (frob vars lexenv-vars
)
593 (frob blocks lexenv-blocks
)
594 (frob tags lexenv-tags
)
595 (frob type-restrictions lexenv-type-restrictions
)
596 lambda cleanup handled-conditions
597 disabled-package-locks policy
)))
599 ;;; Makes a LEXENV, suitable for using in a MACROLET introduced
601 (defun make-restricted-lexenv (lexenv)
602 (flet ((fun-good-p (fun)
603 (destructuring-bind (name . thing
) fun
604 (declare (ignore name
))
608 (cons (aver (eq (car thing
) 'macro
))
611 (destructuring-bind (name . thing
) var
612 (declare (ignore name
))
615 (cons (aver (eq (car thing
) 'macro
))
617 (heap-alien-info nil
)))))
618 (internal-make-lexenv
619 (remove-if-not #'fun-good-p
(lexenv-funs lexenv
))
620 (remove-if-not #'var-good-p
(lexenv-vars lexenv
))
623 (lexenv-type-restrictions lexenv
) ; XXX
626 (lexenv-handled-conditions lexenv
)
627 (lexenv-disabled-package-locks lexenv
)
628 (lexenv-policy lexenv
))))
630 ;;;; flow/DFO/component hackery
632 ;;; Join BLOCK1 and BLOCK2.
633 (defun link-blocks (block1 block2
)
634 (declare (type cblock block1 block2
))
635 (setf (block-succ block1
)
636 (if (block-succ block1
)
637 (%link-blocks block1 block2
)
639 (push block1
(block-pred block2
))
641 (defun %link-blocks
(block1 block2
)
642 (declare (type cblock block1 block2
))
643 (let ((succ1 (block-succ block1
)))
644 (aver (not (memq block2 succ1
)))
645 (cons block2 succ1
)))
647 ;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
648 ;;; this leaves a successor with a single predecessor that ends in an
649 ;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
650 ;;; now be able to be propagated to the successor.
651 (defun unlink-blocks (block1 block2
)
652 (declare (type cblock block1 block2
))
653 (let ((succ1 (block-succ block1
)))
654 (if (eq block2
(car succ1
))
655 (setf (block-succ block1
) (cdr succ1
))
656 (do ((succ (cdr succ1
) (cdr succ
))
658 ((eq (car succ
) block2
)
659 (setf (cdr prev
) (cdr succ
)))
662 (let ((new-pred (delq block1
(block-pred block2
))))
663 (setf (block-pred block2
) new-pred
)
664 (when (singleton-p new-pred
)
665 (let ((pred-block (first new-pred
)))
666 (when (if-p (block-last pred-block
))
667 (setf (block-test-modified pred-block
) t
)))))
670 ;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
671 ;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
672 ;;; consequent/alternative blocks to point to NEW. We also set
673 ;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
674 ;;; the new successor.
675 (defun change-block-successor (block old new
)
676 (declare (type cblock new old block
))
677 (unlink-blocks block old
)
678 (let ((last (block-last block
))
679 (comp (block-component block
)))
680 (setf (component-reanalyze comp
) t
)
683 (setf (block-test-modified block
) t
)
684 (let* ((succ-left (block-succ block
))
685 (new (if (and (eq new
(component-tail comp
))
689 (unless (memq new succ-left
)
690 (link-blocks block new
))
691 (macrolet ((frob (slot)
692 `(when (eq (,slot last
) old
)
693 (setf (,slot last
) new
))))
695 (frob if-alternative
)
696 (when (eq (if-consequent last
)
697 (if-alternative last
))
698 (reoptimize-component (block-component block
) :maybe
)))))
700 (unless (memq new
(block-succ block
))
701 (link-blocks block new
)))))
705 ;;; Unlink a block from the next/prev chain. We also null out the
707 (declaim (ftype (sfunction (cblock) (values)) remove-from-dfo
))
708 (defun remove-from-dfo (block)
709 (let ((next (block-next block
))
710 (prev (block-prev block
)))
711 (setf (block-component block
) nil
)
712 (setf (block-next prev
) next
)
713 (setf (block-prev next
) prev
))
716 ;;; Add BLOCK to the next/prev chain following AFTER. We also set the
717 ;;; COMPONENT to be the same as for AFTER.
718 (defun add-to-dfo (block after
)
719 (declare (type cblock block after
))
720 (let ((next (block-next after
))
721 (comp (block-component after
)))
722 (aver (not (eq (component-kind comp
) :deleted
)))
723 (setf (block-component block
) comp
)
724 (setf (block-next after
) block
)
725 (setf (block-prev block
) after
)
726 (setf (block-next block
) next
)
727 (setf (block-prev next
) block
))
730 ;;; List all NLX-INFOs which BLOCK can exit to.
732 ;;; We hope that no cleanup actions are performed in the middle of
733 ;;; BLOCK, so it is enough to look only at cleanups in the block
734 ;;; end. The tricky thing is a special cleanup block; all its nodes
735 ;;; have the same cleanup info, corresponding to the start, so the
736 ;;; same approach returns safe result.
737 (defun map-block-nlxes (fun block
&optional dx-cleanup-fun
)
738 (loop for cleanup
= (block-end-cleanup block
)
739 then
(node-enclosing-cleanup (cleanup-mess-up cleanup
))
741 do
(let ((mess-up (cleanup-mess-up cleanup
)))
742 (case (cleanup-kind cleanup
)
744 (aver (entry-p mess-up
))
745 (loop for exit in
(entry-exits mess-up
)
746 for nlx-info
= (exit-nlx-info exit
)
747 do
(funcall fun nlx-info
)))
748 ((:catch
:unwind-protect
)
749 (aver (combination-p mess-up
))
750 (let* ((arg-lvar (first (basic-combination-args mess-up
)))
751 (nlx-info (constant-value (ref-leaf (lvar-use arg-lvar
)))))
752 (funcall fun nlx-info
)))
755 (funcall dx-cleanup-fun cleanup
)))))))
757 ;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
758 ;;; the head and tail which are set to T.
759 (declaim (ftype (sfunction (component) (values)) clear-flags
))
760 (defun clear-flags (component)
761 (let ((head (component-head component
))
762 (tail (component-tail component
)))
763 (setf (block-flag head
) t
)
764 (setf (block-flag tail
) t
)
765 (do-blocks (block component
)
766 (setf (block-flag block
) nil
)))
769 ;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
770 ;;; true in the head and tail blocks.
771 (declaim (ftype (sfunction () component
) make-empty-component
))
772 (defun make-empty-component ()
773 (let* ((head (make-block-key :start nil
:component nil
))
774 (tail (make-block-key :start nil
:component nil
))
775 (res (make-component head tail
)))
776 (setf (block-flag head
) t
)
777 (setf (block-flag tail
) t
)
778 (setf (block-component head
) res
)
779 (setf (block-component tail
) res
)
780 (setf (block-next head
) tail
)
781 (setf (block-prev tail
) head
)
784 ;;; Make NODE the LAST node in its block, splitting the block if necessary.
785 ;;; The new block is added to the DFO immediately following NODE's block.
786 (defun node-ends-block (node)
787 (declare (type node node
))
788 (let* ((block (node-block node
))
789 (start (node-next node
))
790 (last (block-last block
)))
791 (unless (eq last node
)
792 (aver (and (eq (ctran-kind start
) :inside-block
)
793 (not (block-delete-p block
))))
794 (let* ((succ (block-succ block
))
796 (make-block-key :start start
797 :component
(block-component block
)
798 :succ succ
:last last
)))
799 (setf (ctran-kind start
) :block-start
)
800 (setf (ctran-use start
) nil
)
801 (setf (block-last block
) node
)
802 (setf (node-next node
) nil
)
805 (cons new-block
(remove block
(block-pred b
)))))
806 (setf (block-succ block
) ())
807 (link-blocks block new-block
)
808 (add-to-dfo new-block block
)
809 (setf (component-reanalyze (block-component block
)) t
)
811 (do ((ctran start
(node-next (ctran-next ctran
))))
813 (setf (ctran-block ctran
) new-block
))
815 (setf (block-type-asserted block
) t
)
816 (setf (block-test-modified block
) t
))))
821 ;;; Deal with deleting the last (read) reference to a LAMBDA-VAR.
822 (defun delete-lambda-var (leaf)
823 (declare (type lambda-var leaf
))
825 ;; Iterate over all local calls flushing the corresponding argument,
826 ;; allowing the computation of the argument to be deleted. We also
827 ;; mark the LET for reoptimization, since it may be that we have
828 ;; deleted its last variable.
829 (let* ((fun (lambda-var-home leaf
))
830 (n (position leaf
(lambda-vars fun
))))
831 (dolist (ref (leaf-refs fun
))
832 (let* ((lvar (node-lvar ref
))
833 (dest (and lvar
(lvar-dest lvar
))))
834 (when (and (combination-p dest
)
835 (eq (basic-combination-fun dest
) lvar
)
836 (eq (basic-combination-kind dest
) :local
))
837 (let* ((args (basic-combination-args dest
))
839 (reoptimize-lvar arg
)
841 (setf (elt args n
) nil
))))))
843 ;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
844 ;; too much difficulty, since we can efficiently implement
845 ;; write-only variables. We iterate over the SETs, marking their
846 ;; blocks for dead code flushing, since we can delete SETs whose
848 (dolist (set (lambda-var-sets leaf
))
849 (setf (block-flush-p (node-block set
)) t
))
853 ;;; Note that something interesting has happened to VAR.
854 (defun reoptimize-lambda-var (var)
855 (declare (type lambda-var var
))
856 (let ((fun (lambda-var-home var
)))
857 ;; We only deal with LET variables, marking the corresponding
858 ;; initial value arg as needing to be reoptimized.
859 (when (and (eq (functional-kind fun
) :let
)
861 (do ((args (basic-combination-args
862 (lvar-dest (node-lvar (first (leaf-refs fun
)))))
864 (vars (lambda-vars fun
) (cdr vars
)))
866 (reoptimize-lvar (car args
))))))
869 ;;; Delete a function that has no references. This need only be called
870 ;;; on functions that never had any references, since otherwise
871 ;;; DELETE-REF will handle the deletion.
872 (defun delete-functional (fun)
873 (aver (and (null (leaf-refs fun
))
874 (not (functional-entry-fun fun
))))
876 (optional-dispatch (delete-optional-dispatch fun
))
877 (clambda (delete-lambda fun
)))
880 ;;; Deal with deleting the last reference to a CLAMBDA, which means
881 ;;; that the lambda is unreachable, so that its body may be
882 ;;; deleted. We set FUNCTIONAL-KIND to :DELETED and rely on
883 ;;; IR1-OPTIMIZE to delete its blocks.
884 (defun delete-lambda (clambda)
885 (declare (type clambda clambda
))
886 (let ((original-kind (functional-kind clambda
))
887 (bind (lambda-bind clambda
)))
888 (aver (not (member original-kind
'(:deleted
:toplevel
))))
889 (aver (not (functional-has-external-references-p clambda
)))
890 (aver (or (eq original-kind
:zombie
) bind
))
891 (setf (functional-kind clambda
) :deleted
)
892 (setf (lambda-bind clambda
) nil
)
894 (labels ((delete-children (lambda)
895 (dolist (child (lambda-children lambda
))
896 (cond ((eq (functional-kind child
) :deleted
)
897 (delete-children child
))
899 (delete-lambda child
))))
900 (setf (lambda-children lambda
) nil
)
901 (setf (lambda-parent lambda
) nil
)))
902 (delete-children clambda
))
904 ;; (The IF test is (FUNCTIONAL-SOMEWHAT-LETLIKE-P CLAMBDA), except
905 ;; that we're using the old value of the KIND slot, not the
906 ;; current slot value, which has now been set to :DELETED.)
909 ((:let
:mv-let
:assignment
)
910 (let ((bind-block (node-block bind
)))
911 (mark-for-deletion bind-block
))
912 (let ((home (lambda-home clambda
)))
913 (setf (lambda-lets home
) (delete clambda
(lambda-lets home
))))
914 ;; KLUDGE: In presence of NLEs we cannot always understand that
915 ;; LET's BIND dominates its body [for a LET "its" body is not
916 ;; quite its]; let's delete too dangerous for IR2 stuff. --
918 (dolist (var (lambda-vars clambda
))
919 (flet ((delete-node (node)
920 (mark-for-deletion (node-block node
))))
921 (mapc #'delete-node
(leaf-refs var
))
922 (mapc #'delete-node
(lambda-var-sets var
)))))
924 ;; Function has no reachable references.
925 (dolist (ref (lambda-refs clambda
))
926 (mark-for-deletion (node-block ref
)))
927 ;; If the function isn't a LET, we unlink the function head
928 ;; and tail from the component head and tail to indicate that
929 ;; the code is unreachable. We also delete the function from
930 ;; COMPONENT-LAMBDAS (it won't be there before local call
931 ;; analysis, but no matter.) If the lambda was never
932 ;; referenced, we give a note.
933 (let* ((bind-block (node-block bind
))
934 (component (block-component bind-block
))
935 (return (lambda-return clambda
))
936 (return-block (and return
(node-block return
))))
937 (unless (leaf-ever-used clambda
)
938 (let ((*compiler-error-context
* bind
))
939 (compiler-notify 'code-deletion-note
940 :format-control
"deleting unused function~:[.~;~:*~% ~S~]"
941 :format-arguments
(list (leaf-debug-name clambda
)))))
942 (unless (block-delete-p bind-block
)
943 (unlink-blocks (component-head component
) bind-block
))
944 (when (and return-block
(not (block-delete-p return-block
)))
945 (mark-for-deletion return-block
)
946 (unlink-blocks return-block
(component-tail component
)))
947 (setf (component-reanalyze component
) t
)
948 (let ((tails (lambda-tail-set clambda
)))
949 (setf (tail-set-funs tails
)
950 (delete clambda
(tail-set-funs tails
)))
951 (setf (lambda-tail-set clambda
) nil
))
952 (setf (component-lambdas component
)
953 (delq clambda
(component-lambdas component
))))))
955 ;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
956 ;; ENTRY-FUN so that people will know that it is not an entry
958 (when (eq original-kind
:external
)
959 (let ((fun (functional-entry-fun clambda
)))
960 (setf (functional-entry-fun fun
) nil
)
961 (when (optional-dispatch-p fun
)
962 (delete-optional-dispatch fun
)))))
966 ;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
967 ;;; have to be a bit more careful than with lambdas, since DELETE-REF
968 ;;; is used both before and after local call analysis. Afterward, all
969 ;;; references to still-existing OPTIONAL-DISPATCHes have been moved
970 ;;; to the XEP, leaving it with no references at all. So we look at
971 ;;; the XEP to see whether an optional-dispatch is still really being
972 ;;; used. But before local call analysis, there are no XEPs, and all
973 ;;; references are direct.
975 ;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
976 ;;; entry-points, making them be normal lambdas, and then deleting the
977 ;;; ones with no references. This deletes any e-p lambdas that were
978 ;;; either never referenced, or couldn't be deleted when the last
979 ;;; reference was deleted (due to their :OPTIONAL kind.)
981 ;;; Note that the last optional entry point may alias the main entry,
982 ;;; so when we process the main entry, its KIND may have been changed
983 ;;; to NIL or even converted to a LETlike value.
984 (defun delete-optional-dispatch (leaf)
985 (declare (type optional-dispatch leaf
))
986 (let ((entry (functional-entry-fun leaf
)))
987 (unless (and entry
(leaf-refs entry
))
988 (aver (or (not entry
) (eq (functional-kind entry
) :deleted
)))
989 (setf (functional-kind leaf
) :deleted
)
992 (unless (eq (functional-kind fun
) :deleted
)
993 (aver (eq (functional-kind fun
) :optional
))
994 (setf (functional-kind fun
) nil
)
995 (let ((refs (leaf-refs fun
)))
999 (or (maybe-let-convert fun
)
1000 (maybe-convert-to-assignment fun
)))
1002 (maybe-convert-to-assignment fun
)))))))
1004 (dolist (ep (optional-dispatch-entry-points leaf
))
1005 (when (promise-ready-p ep
)
1007 (when (optional-dispatch-more-entry leaf
)
1008 (frob (optional-dispatch-more-entry leaf
)))
1009 (let ((main (optional-dispatch-main-entry leaf
)))
1011 (setf (functional-entry-fun entry
) main
)
1012 (setf (functional-entry-fun main
) entry
))
1013 (when (eq (functional-kind main
) :optional
)
1018 ;;; Do stuff to delete the semantic attachments of a REF node. When
1019 ;;; this leaves zero or one reference, we do a type dispatch off of
1020 ;;; the leaf to determine if a special action is appropriate.
1021 (defun delete-ref (ref)
1022 (declare (type ref ref
))
1023 (let* ((leaf (ref-leaf ref
))
1024 (refs (delq ref
(leaf-refs leaf
))))
1025 (setf (leaf-refs leaf
) refs
)
1030 (delete-lambda-var leaf
))
1032 (ecase (functional-kind leaf
)
1033 ((nil :let
:mv-let
:assignment
:escape
:cleanup
)
1034 (aver (null (functional-entry-fun leaf
)))
1035 (delete-lambda leaf
))
1037 (delete-lambda leaf
))
1038 ((:deleted
:zombie
:optional
))))
1040 (unless (eq (functional-kind leaf
) :deleted
)
1041 (delete-optional-dispatch leaf
)))))
1044 (clambda (or (maybe-let-convert leaf
)
1045 (maybe-convert-to-assignment leaf
)))
1046 (lambda-var (reoptimize-lambda-var leaf
))))
1049 (clambda (maybe-convert-to-assignment leaf
))))))
1053 ;;; This function is called by people who delete nodes; it provides a
1054 ;;; way to indicate that the value of a lvar is no longer used. We
1055 ;;; null out the LVAR-DEST, set FLUSH-P in the blocks containing uses
1056 ;;; of LVAR and set COMPONENT-REOPTIMIZE.
1057 (defun flush-dest (lvar)
1058 (declare (type (or lvar null
) lvar
))
1060 (setf (lvar-dest lvar
) nil
)
1061 (flush-lvar-externally-checkable-type lvar
)
1063 (let ((prev (node-prev use
)))
1064 (let ((block (ctran-block prev
)))
1065 (reoptimize-component (block-component block
) t
)
1066 (setf (block-attributep (block-flags block
)
1067 flush-p type-asserted type-check
)
1069 (setf (node-lvar use
) nil
))
1070 (setf (lvar-uses lvar
) nil
))
1073 (defun delete-dest (lvar)
1075 (let* ((dest (lvar-dest lvar
))
1076 (prev (node-prev dest
)))
1077 (let ((block (ctran-block prev
)))
1078 (unless (block-delete-p block
)
1079 (mark-for-deletion block
))))))
1081 ;;; Queue the block for deletion
1082 (defun delete-block-lazily (block)
1083 (declare (type cblock block
))
1084 (unless (block-delete-p block
)
1085 (setf (block-delete-p block
) t
)
1086 (push block
(component-delete-blocks (block-component block
)))))
1088 ;;; Do a graph walk backward from BLOCK, marking all predecessor
1089 ;;; blocks with the DELETE-P flag.
1090 (defun mark-for-deletion (block)
1091 (declare (type cblock block
))
1092 (let* ((component (block-component block
))
1093 (head (component-head component
)))
1094 (labels ((helper (block)
1095 (delete-block-lazily block
)
1096 (dolist (pred (block-pred block
))
1097 (unless (or (block-delete-p pred
)
1100 (unless (block-delete-p block
)
1102 (setf (component-reanalyze component
) t
))))
1105 ;;; This function does what is necessary to eliminate the code in it
1106 ;;; from the IR1 representation. This involves unlinking it from its
1107 ;;; predecessors and successors and deleting various node-specific
1108 ;;; semantic information. BLOCK must be already removed from
1109 ;;; COMPONENT-DELETE-BLOCKS.
1110 (defun delete-block (block &optional silent
)
1111 (declare (type cblock block
))
1112 (aver (block-component block
)) ; else block is already deleted!
1113 #!+high-security
(aver (not (memq block
(component-delete-blocks (block-component block
)))))
1115 (note-block-deletion block
))
1116 (setf (block-delete-p block
) t
)
1118 (dolist (b (block-pred block
))
1119 (unlink-blocks b block
)
1120 ;; In bug 147 the almost-all-blocks-have-a-successor invariant was
1121 ;; broken when successors were deleted without setting the
1122 ;; BLOCK-DELETE-P flags of their predececessors. Make sure that
1123 ;; doesn't happen again.
1124 (aver (not (and (null (block-succ b
))
1125 (not (block-delete-p b
))
1126 (not (eq b
(component-head (block-component b
))))))))
1127 (dolist (b (block-succ block
))
1128 (unlink-blocks block b
))
1130 (do-nodes-carefully (node block
)
1131 (when (valued-node-p node
)
1132 (delete-lvar-use node
))
1134 (ref (delete-ref node
))
1135 (cif (flush-dest (if-test node
)))
1136 ;; The next two cases serve to maintain the invariant that a LET
1137 ;; always has a well-formed COMBINATION, REF and BIND. We delete
1138 ;; the lambda whenever we delete any of these, but we must be
1139 ;; careful that this LET has not already been partially deleted.
1141 (when (and (eq (basic-combination-kind node
) :local
)
1142 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
1143 (lvar-uses (basic-combination-fun node
)))
1144 (let ((fun (combination-lambda node
)))
1145 ;; If our REF was the second-to-last ref, and has been
1146 ;; deleted, then FUN may be a LET for some other
1148 (when (and (functional-letlike-p fun
)
1149 (eq (let-combination fun
) node
))
1150 (delete-lambda fun
))))
1151 (flush-dest (basic-combination-fun node
))
1152 (dolist (arg (basic-combination-args node
))
1153 (when arg
(flush-dest arg
))))
1155 (let ((lambda (bind-lambda node
)))
1156 (unless (eq (functional-kind lambda
) :deleted
)
1157 (delete-lambda lambda
))))
1159 (let ((value (exit-value node
))
1160 (entry (exit-entry node
)))
1164 (setf (entry-exits entry
)
1165 (delq node
(entry-exits entry
))))))
1167 (dolist (exit (entry-exits node
))
1168 (mark-for-deletion (node-block exit
)))
1169 (let ((home (node-home-lambda node
)))
1170 (setf (lambda-entries home
) (delq node
(lambda-entries home
)))))
1172 (flush-dest (return-result node
))
1173 (delete-return node
))
1175 (flush-dest (set-value node
))
1176 (let ((var (set-var node
)))
1177 (setf (basic-var-sets var
)
1178 (delete node
(basic-var-sets var
)))))
1180 (flush-dest (cast-value node
)))))
1182 (remove-from-dfo block
)
1185 ;;; Do stuff to indicate that the return node NODE is being deleted.
1186 (defun delete-return (node)
1187 (declare (type creturn node
))
1188 (let* ((fun (return-lambda node
))
1189 (tail-set (lambda-tail-set fun
)))
1190 (aver (lambda-return fun
))
1191 (setf (lambda-return fun
) nil
)
1192 (when (and tail-set
(not (find-if #'lambda-return
1193 (tail-set-funs tail-set
))))
1194 (setf (tail-set-type tail-set
) *empty-type
*)))
1197 ;;; If any of the VARS in FUN was never referenced and was not
1198 ;;; declared IGNORE, then complain.
1199 (defun note-unreferenced-vars (fun)
1200 (declare (type clambda fun
))
1201 (dolist (var (lambda-vars fun
))
1202 (unless (or (leaf-ever-used var
)
1203 (lambda-var-ignorep var
))
1204 (let ((*compiler-error-context
* (lambda-bind fun
)))
1205 (unless (policy *compiler-error-context
* (= inhibit-warnings
3))
1206 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
1207 ;; requires this to be no more than a STYLE-WARNING.
1209 (compiler-style-warn "The variable ~S is defined but never used."
1210 (leaf-debug-name var
))
1211 ;; There's no reason to accept this kind of equivocation
1212 ;; when compiling our own code, though.
1214 (warn "The variable ~S is defined but never used."
1215 (leaf-debug-name var
)))
1216 (setf (leaf-ever-used var
) t
)))) ; to avoid repeated warnings? -- WHN
1219 (defvar *deletion-ignored-objects
* '(t nil
))
1221 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
1222 ;;; our recursion so that we don't get lost in circular structures. We
1223 ;;; ignore the car of forms if they are a symbol (to prevent confusing
1224 ;;; function referencess with variables), and we also ignore anything
1226 (defun present-in-form (obj form depth
)
1227 (declare (type (integer 0 20) depth
))
1228 (cond ((= depth
20) nil
)
1232 (let ((first (car form
))
1234 (if (member first
'(quote function
))
1236 (or (and (not (symbolp first
))
1237 (present-in-form obj first depth
))
1238 (do ((l (cdr form
) (cdr l
))
1240 ((or (atom l
) (> n
100))
1242 (declare (fixnum n
))
1243 (when (present-in-form obj
(car l
) depth
)
1246 ;;; This function is called on a block immediately before we delete
1247 ;;; it. We check to see whether any of the code about to die appeared
1248 ;;; in the original source, and emit a note if so.
1250 ;;; If the block was in a lambda is now deleted, then we ignore the
1251 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
1252 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
1253 ;;; reasonable for a function to not return, and there is a different
1254 ;;; note for that case anyway.
1256 ;;; If the actual source is an atom, then we use a bunch of heuristics
1257 ;;; to guess whether this reference really appeared in the original
1259 ;;; -- If a symbol, it must be interned and not a keyword.
1260 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
1261 ;;; or a character.)
1262 ;;; -- The atom must be "present" in the original source form, and
1263 ;;; present in all intervening actual source forms.
1264 (defun note-block-deletion (block)
1265 (let ((home (block-home-lambda block
)))
1266 (unless (eq (functional-kind home
) :deleted
)
1267 (do-nodes (node nil block
)
1268 (let* ((path (node-source-path node
))
1269 (first (first path
)))
1270 (when (or (eq first
'original-source-start
)
1272 (or (not (symbolp first
))
1273 (let ((pkg (symbol-package first
)))
1275 (not (eq pkg
(symbol-package :end
))))))
1276 (not (member first
*deletion-ignored-objects
*))
1277 (not (typep first
'(or fixnum character
)))
1279 (present-in-form first x
0))
1280 (source-path-forms path
))
1281 (present-in-form first
(find-original-source path
)
1283 (unless (return-p node
)
1284 (let ((*compiler-error-context
* node
))
1285 (compiler-notify 'code-deletion-note
1286 :format-control
"deleting unreachable code"
1287 :format-arguments nil
)))
1291 ;;; Delete a node from a block, deleting the block if there are no
1292 ;;; nodes left. We remove the node from the uses of its LVAR.
1294 ;;; If the node is the last node, there must be exactly one successor.
1295 ;;; We link all of our precedessors to the successor and unlink the
1296 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1297 ;;; left, and the block is a successor of itself, then we replace the
1298 ;;; only node with a degenerate exit node. This provides a way to
1299 ;;; represent the bodyless infinite loop, given the prohibition on
1300 ;;; empty blocks in IR1.
1301 (defun unlink-node (node)
1302 (declare (type node node
))
1303 (when (valued-node-p node
)
1304 (delete-lvar-use node
))
1306 (let* ((ctran (node-next node
))
1307 (next (and ctran
(ctran-next ctran
)))
1308 (prev (node-prev node
))
1309 (block (ctran-block prev
))
1310 (prev-kind (ctran-kind prev
))
1311 (last (block-last block
)))
1313 (setf (block-type-asserted block
) t
)
1314 (setf (block-test-modified block
) t
)
1316 (cond ((or (eq prev-kind
:inside-block
)
1317 (and (eq prev-kind
:block-start
)
1318 (not (eq node last
))))
1319 (cond ((eq node last
)
1320 (setf (block-last block
) (ctran-use prev
))
1321 (setf (node-next (ctran-use prev
)) nil
))
1323 (setf (ctran-next prev
) next
)
1324 (setf (node-prev next
) prev
)
1325 (when (if-p next
) ; AOP wanted
1326 (reoptimize-lvar (if-test next
)))))
1327 (setf (node-prev node
) nil
)
1330 (aver (eq prev-kind
:block-start
))
1331 (aver (eq node last
))
1332 (let* ((succ (block-succ block
))
1333 (next (first succ
)))
1334 (aver (singleton-p succ
))
1336 ((eq block
(first succ
))
1337 (with-ir1-environment-from-node node
1338 (let ((exit (make-exit)))
1339 (setf (ctran-next prev
) nil
)
1340 (link-node-to-previous-ctran exit prev
)
1341 (setf (block-last block
) exit
)))
1342 (setf (node-prev node
) nil
)
1345 (aver (eq (block-start-cleanup block
)
1346 (block-end-cleanup block
)))
1347 (unlink-blocks block next
)
1348 (dolist (pred (block-pred block
))
1349 (change-block-successor pred block next
))
1350 (when (block-delete-p block
)
1351 (let ((component (block-component block
)))
1352 (setf (component-delete-blocks component
)
1353 (delq block
(component-delete-blocks component
)))))
1354 (remove-from-dfo block
)
1355 (setf (block-delete-p block
) t
)
1356 (setf (node-prev node
) nil
)
1359 ;;; Return true if CTRAN has been deleted, false if it is still a valid
1361 (defun ctran-deleted-p (ctran)
1362 (declare (type ctran ctran
))
1363 (let ((block (ctran-block ctran
)))
1364 (or (not (block-component block
))
1365 (block-delete-p block
))))
1367 ;;; Return true if NODE has been deleted, false if it is still a valid
1369 (defun node-deleted (node)
1370 (declare (type node node
))
1371 (let ((prev (node-prev node
)))
1373 (ctran-deleted-p prev
))))
1375 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1376 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1377 ;;; triggered by deletion.
1378 (defun delete-component (component)
1379 (declare (type component component
))
1380 (aver (null (component-new-functionals component
)))
1381 (setf (component-kind component
) :deleted
)
1382 (do-blocks (block component
)
1383 (delete-block-lazily block
))
1384 (dolist (fun (component-lambdas component
))
1385 (unless (eq (functional-kind fun
) :deleted
)
1386 (setf (functional-kind fun
) nil
)
1387 (setf (functional-entry-fun fun
) nil
)
1388 (setf (leaf-refs fun
) nil
)
1389 (delete-functional fun
)))
1390 (clean-component component
)
1393 ;;; Remove all pending blocks to be deleted. Return the nearest live
1394 ;;; block after or equal to BLOCK.
1395 (defun clean-component (component &optional block
)
1396 (loop while
(component-delete-blocks component
)
1397 ;; actual deletion of a block may queue new blocks
1398 do
(let ((current (pop (component-delete-blocks component
))))
1399 (when (eq block current
)
1400 (setq block
(block-next block
)))
1401 (delete-block current
)))
1404 ;;; Convert code of the form
1405 ;;; (FOO ... (FUN ...) ...)
1407 ;;; (FOO ... ... ...).
1408 ;;; In other words, replace the function combination FUN by its
1409 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1410 ;;; to blow out of whatever transform called this. Note, as the number
1411 ;;; of arguments changes, the transform must be prepared to return a
1412 ;;; lambda with a new lambda-list with the correct number of
1414 (defun extract-fun-args (lvar fun num-args
)
1416 "If LVAR is a call to FUN with NUM-ARGS args, change those arguments
1417 to feed directly to the LVAR-DEST of LVAR, which must be a
1419 (declare (type lvar lvar
)
1421 (type index num-args
))
1422 (let ((outside (lvar-dest lvar
))
1423 (inside (lvar-uses lvar
)))
1424 (aver (combination-p outside
))
1425 (unless (combination-p inside
)
1426 (give-up-ir1-transform))
1427 (let ((inside-fun (combination-fun inside
)))
1428 (unless (eq (lvar-fun-name inside-fun
) fun
)
1429 (give-up-ir1-transform))
1430 (let ((inside-args (combination-args inside
)))
1431 (unless (= (length inside-args
) num-args
)
1432 (give-up-ir1-transform))
1433 (let* ((outside-args (combination-args outside
))
1434 (arg-position (position lvar outside-args
))
1435 (before-args (subseq outside-args
0 arg-position
))
1436 (after-args (subseq outside-args
(1+ arg-position
))))
1437 (dolist (arg inside-args
)
1438 (setf (lvar-dest arg
) outside
)
1439 (flush-lvar-externally-checkable-type arg
))
1440 (setf (combination-args inside
) nil
)
1441 (setf (combination-args outside
)
1442 (append before-args inside-args after-args
))
1443 (change-ref-leaf (lvar-uses inside-fun
)
1444 (find-free-fun 'list
"???"))
1445 (setf (combination-fun-info inside
) (info :function
:info
'list
)
1446 (combination-kind inside
) :known
)
1447 (setf (node-derived-type inside
) *wild-type
*)
1451 (defun flush-combination (combination)
1452 (declare (type combination combination
))
1453 (flush-dest (combination-fun combination
))
1454 (dolist (arg (combination-args combination
))
1456 (unlink-node combination
)
1462 ;;; Change the LEAF that a REF refers to.
1463 (defun change-ref-leaf (ref leaf
)
1464 (declare (type ref ref
) (type leaf leaf
))
1465 (unless (eq (ref-leaf ref
) leaf
)
1466 (push ref
(leaf-refs leaf
))
1468 (setf (ref-leaf ref
) leaf
)
1469 (setf (leaf-ever-used leaf
) t
)
1470 (let* ((ltype (leaf-type leaf
))
1471 (vltype (make-single-value-type ltype
)))
1472 (if (let* ((lvar (node-lvar ref
))
1473 (dest (and lvar
(lvar-dest lvar
))))
1474 (and (basic-combination-p dest
)
1475 (eq lvar
(basic-combination-fun dest
))
1476 (csubtypep ltype
(specifier-type 'function
))))
1477 (setf (node-derived-type ref
) vltype
)
1478 (derive-node-type ref vltype
)))
1479 (reoptimize-lvar (node-lvar ref
)))
1482 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1483 (defun substitute-leaf (new-leaf old-leaf
)
1484 (declare (type leaf new-leaf old-leaf
))
1485 (dolist (ref (leaf-refs old-leaf
))
1486 (change-ref-leaf ref new-leaf
))
1489 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1490 ;;; whether to substitute
1491 (defun substitute-leaf-if (test new-leaf old-leaf
)
1492 (declare (type leaf new-leaf old-leaf
) (type function test
))
1493 (dolist (ref (leaf-refs old-leaf
))
1494 (when (funcall test ref
)
1495 (change-ref-leaf ref new-leaf
)))
1498 ;;; Return a LEAF which represents the specified constant object. If
1499 ;;; the object is not in *CONSTANTS*, then we create a new constant
1500 ;;; LEAF and enter it.
1501 (defun find-constant (object)
1503 ;; FIXME: What is the significance of this test? ("things
1504 ;; that are worth uniquifying"?)
1505 '(or symbol number character instance
))
1506 (or (gethash object
*constants
*)
1507 (setf (gethash object
*constants
*)
1508 (make-constant :value object
1509 :%source-name
'.anonymous.
1510 :type
(ctype-of object
)
1511 :where-from
:defined
)))
1512 (make-constant :value object
1513 :%source-name
'.anonymous.
1514 :type
(ctype-of object
)
1515 :where-from
:defined
)))
1517 ;;; Return true if VAR would have to be closed over if environment
1518 ;;; analysis ran now (i.e. if there are any uses that have a different
1519 ;;; home lambda than VAR's home.)
1520 (defun closure-var-p (var)
1521 (declare (type lambda-var var
))
1522 (let ((home (lambda-var-home var
)))
1523 (cond ((eq (functional-kind home
) :deleted
)
1525 (t (let ((home (lambda-home home
)))
1528 :key
#'node-home-lambda
1530 (or (frob (leaf-refs var
))
1531 (frob (basic-var-sets var
)))))))))
1533 ;;; If there is a non-local exit noted in ENTRY's environment that
1534 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1535 (defun find-nlx-info (exit)
1536 (declare (type exit exit
))
1537 (let* ((entry (exit-entry exit
))
1538 (cleanup (entry-cleanup entry
))
1539 (block (first (block-succ (node-block exit
)))))
1540 (dolist (nlx (physenv-nlx-info (node-physenv entry
)) nil
)
1541 (when (and (eq (nlx-info-block nlx
) block
)
1542 (eq (nlx-info-cleanup nlx
) cleanup
))
1545 (defun nlx-info-lvar (nlx)
1546 (declare (type nlx-info nlx
))
1547 (node-lvar (block-last (nlx-info-target nlx
))))
1549 ;;;; functional hackery
1551 (declaim (ftype (sfunction (functional) clambda
) main-entry
))
1552 (defun main-entry (functional)
1553 (etypecase functional
1554 (clambda functional
)
1556 (optional-dispatch-main-entry functional
))))
1558 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1559 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1560 ;;; optional with null default and no SUPPLIED-P. There must be a
1561 ;;; &REST arg with no references.
1562 (declaim (ftype (sfunction (functional) boolean
) looks-like-an-mv-bind
))
1563 (defun looks-like-an-mv-bind (functional)
1564 (and (optional-dispatch-p functional
)
1565 (do ((arg (optional-dispatch-arglist functional
) (cdr arg
)))
1567 (let ((info (lambda-var-arg-info (car arg
))))
1568 (unless info
(return nil
))
1569 (case (arg-info-kind info
)
1571 (when (or (arg-info-supplied-p info
) (arg-info-default info
))
1574 (return (and (null (cdr arg
)) (null (leaf-refs (car arg
))))))
1578 ;;; Return true if function is an external entry point. This is true
1579 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1580 ;;; (:TOPLEVEL kind.)
1582 (declare (type functional fun
))
1583 (not (null (member (functional-kind fun
) '(:external
:toplevel
)))))
1585 ;;; If LVAR's only use is a non-notinline global function reference,
1586 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1587 ;;; is true, then we don't care if the leaf is NOTINLINE.
1588 (defun lvar-fun-name (lvar &optional notinline-ok
)
1589 (declare (type lvar lvar
))
1590 (let ((use (lvar-uses lvar
)))
1592 (let ((leaf (ref-leaf use
)))
1593 (if (and (global-var-p leaf
)
1594 (eq (global-var-kind leaf
) :global-function
)
1595 (or (not (defined-fun-p leaf
))
1596 (not (eq (defined-fun-inlinep leaf
) :notinline
))
1598 (leaf-source-name leaf
)
1602 ;;; Return the source name of a combination. (This is an idiom
1603 ;;; which was used in CMU CL. I gather it always works. -- WHN)
1604 (defun combination-fun-source-name (combination)
1605 (let ((ref (lvar-uses (combination-fun combination
))))
1606 (leaf-source-name (ref-leaf ref
))))
1608 ;;; Return the COMBINATION node that is the call to the LET FUN.
1609 (defun let-combination (fun)
1610 (declare (type clambda fun
))
1611 (aver (functional-letlike-p fun
))
1612 (lvar-dest (node-lvar (first (leaf-refs fun
)))))
1614 ;;; Return the initial value lvar for a LET variable, or NIL if there
1616 (defun let-var-initial-value (var)
1617 (declare (type lambda-var var
))
1618 (let ((fun (lambda-var-home var
)))
1619 (elt (combination-args (let-combination fun
))
1620 (position-or-lose var
(lambda-vars fun
)))))
1622 ;;; Return the LAMBDA that is called by the local CALL.
1623 (defun combination-lambda (call)
1624 (declare (type basic-combination call
))
1625 (aver (eq (basic-combination-kind call
) :local
))
1626 (ref-leaf (lvar-uses (basic-combination-fun call
))))
1628 (defvar *inline-expansion-limit
* 200
1630 "an upper limit on the number of inline function calls that will be expanded
1631 in any given code object (single function or block compilation)")
1633 ;;; Check whether NODE's component has exceeded its inline expansion
1634 ;;; limit, and warn if so, returning NIL.
1635 (defun inline-expansion-ok (node)
1636 (let ((expanded (incf (component-inline-expansions
1638 (node-block node
))))))
1639 (cond ((> expanded
*inline-expansion-limit
*) nil
)
1640 ((= expanded
*inline-expansion-limit
*)
1641 ;; FIXME: If the objective is to stop the recursive
1642 ;; expansion of inline functions, wouldn't it be more
1643 ;; correct to look back through surrounding expansions
1644 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1645 ;; possibly stored elsewhere too) and suppress expansion
1646 ;; and print this warning when the function being proposed
1647 ;; for inline expansion is found there? (I don't like the
1648 ;; arbitrary numerical limit in principle, and I think
1649 ;; it'll be a nuisance in practice if we ever want the
1650 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1651 ;; arbitrarily huge blocks of code. -- WHN)
1652 (let ((*compiler-error-context
* node
))
1653 (compiler-notify "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1654 probably trying to~% ~
1655 inline a recursive function."
1656 *inline-expansion-limit
*))
1660 ;;; Make sure that FUNCTIONAL is not let-converted or deleted.
1661 (defun assure-functional-live-p (functional)
1662 (declare (type functional functional
))
1664 ;; looks LET-converted
1665 (functional-somewhat-letlike-p functional
)
1666 ;; It's possible for a LET-converted function to end up
1667 ;; deleted later. In that case, for the purposes of this
1668 ;; analysis, it is LET-converted: LET-converted functionals
1669 ;; are too badly trashed to expand them inline, and deleted
1670 ;; LET-converted functionals are even worse.
1671 (memq (functional-kind functional
) '(:deleted
:zombie
))))
1672 (throw 'locall-already-let-converted functional
)))
1674 (defun call-full-like-p (call)
1675 (declare (type combination call
))
1676 (let ((kind (basic-combination-kind call
)))
1678 (and (eq kind
:known
)
1679 (let ((info (basic-combination-fun-info call
)))
1681 (not (fun-info-ir2-convert info
))
1682 (dolist (template (fun-info-templates info
) t
)
1683 (when (eq (template-ltn-policy template
) :fast-safe
)
1684 (multiple-value-bind (val win
)
1685 (valid-fun-use call
(template-type template
))
1686 (when (or val
(not win
)) (return nil
)))))))))))
1690 ;;; Apply a function to some arguments, returning a list of the values
1691 ;;; resulting of the evaluation. If an error is signalled during the
1692 ;;; application, then we produce a warning message using WARN-FUN and
1693 ;;; return NIL as our second value to indicate this. NODE is used as
1694 ;;; the error context for any error message, and CONTEXT is a string
1695 ;;; that is spliced into the warning.
1696 (declaim (ftype (sfunction ((or symbol function
) list node function string
)
1697 (values list boolean
))
1699 (defun careful-call (function args node warn-fun context
)
1701 (multiple-value-list
1702 (handler-case (apply function args
)
1704 (let ((*compiler-error-context
* node
))
1705 (funcall warn-fun
"Lisp error during ~A:~%~A" context condition
)
1706 (return-from careful-call
(values nil nil
))))))
1709 ;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
1712 ((deffrob (basic careful compiler transform
)
1714 (defun ,careful
(specifier)
1715 (handler-case (,basic specifier
)
1716 (sb!kernel
::arg-count-error
(condition)
1717 (values nil
(list (format nil
"~A" condition
))))
1718 (simple-error (condition)
1719 (values nil
(list* (simple-condition-format-control condition
)
1720 (simple-condition-format-arguments condition
))))))
1721 (defun ,compiler
(specifier)
1722 (multiple-value-bind (type error-args
) (,careful specifier
)
1724 (apply #'compiler-error error-args
))))
1725 (defun ,transform
(specifier)
1726 (multiple-value-bind (type error-args
) (,careful specifier
)
1728 (apply #'give-up-ir1-transform
1730 (deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type
)
1731 (deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type
))
1734 ;;;; utilities used at run-time for parsing &KEY args in IR1
1736 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1737 ;;; the lvar for the value of the &KEY argument KEY in the list of
1738 ;;; lvars ARGS. It returns the lvar if the keyword is present, or NIL
1739 ;;; otherwise. The legality and constantness of the keywords should
1740 ;;; already have been checked.
1741 (declaim (ftype (sfunction (list keyword
) (or lvar null
))
1743 (defun find-keyword-lvar (args key
)
1744 (do ((arg args
(cddr arg
)))
1746 (when (eq (lvar-value (first arg
)) key
)
1747 (return (second arg
)))))
1749 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1750 ;;; verify that alternating lvars in ARGS are constant and that there
1751 ;;; is an even number of args.
1752 (declaim (ftype (sfunction (list) boolean
) check-key-args-constant
))
1753 (defun check-key-args-constant (args)
1754 (do ((arg args
(cddr arg
)))
1756 (unless (and (rest arg
)
1757 (constant-lvar-p (first arg
)))
1760 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1761 ;;; verify that the list of lvars ARGS is a well-formed &KEY arglist
1762 ;;; and that only keywords present in the list KEYS are supplied.
1763 (declaim (ftype (sfunction (list list
) boolean
) check-transform-keys
))
1764 (defun check-transform-keys (args keys
)
1765 (and (check-key-args-constant args
)
1766 (do ((arg args
(cddr arg
)))
1768 (unless (member (lvar-value (first arg
)) keys
)
1773 ;;; Called by the expansion of the EVENT macro.
1774 (declaim (ftype (sfunction (event-info (or node null
)) *) %event
))
1775 (defun %event
(info node
)
1776 (incf (event-info-count info
))
1777 (when (and (>= (event-info-level info
) *event-note-threshold
*)
1778 (policy (or node
*lexenv
*)
1779 (= inhibit-warnings
0)))
1780 (let ((*compiler-error-context
* node
))
1781 (compiler-notify (event-info-description info
))))
1783 (let ((action (event-info-action info
)))
1784 (when action
(funcall action node
))))
1787 (defun make-cast (value type policy
)
1788 (declare (type lvar value
)
1790 (type policy policy
))
1791 (%make-cast
:asserted-type type
1792 :type-to-check
(maybe-weaken-check type policy
)
1794 :derived-type
(coerce-to-values type
)))
1796 (defun cast-type-check (cast)
1797 (declare (type cast cast
))
1798 (when (cast-reoptimize cast
)
1799 (ir1-optimize-cast cast t
))
1800 (cast-%type-check cast
))
1802 (defun note-single-valuified-lvar (lvar)
1803 (declare (type (or lvar null
) lvar
))
1805 (let ((use (lvar-uses lvar
)))
1807 (let ((leaf (ref-leaf use
)))
1808 (when (and (lambda-var-p leaf
)
1809 (null (rest (leaf-refs leaf
))))
1810 (reoptimize-lambda-var leaf
))))
1811 ((or (listp use
) (combination-p use
))
1812 (do-uses (node lvar
)
1813 (setf (node-reoptimize node
) t
)
1814 (setf (block-reoptimize (node-block node
)) t
)
1815 (reoptimize-component (node-component node
) :maybe
)))))))
