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 (defun note-local-functional (fun)
1019 (declare (type functional fun))
1020 (when (and (leaf-has-source-name-p fun)
1021 (eq (leaf-source-name fun) (functional-debug-name fun)))
1022 (let ((name (leaf-source-name fun)))
1023 (let ((defined-fun (gethash name *free-funs*)))
1024 (when (and defined-fun
1025 (defined-fun-p defined-fun)
1026 (eq (defined-fun-functional defined-fun) fun))
1027 (remhash name *free-funs*))))))
1029 ;;; Do stuff to delete the semantic attachments of a REF node. When
1030 ;;; this leaves zero or one reference, we do a type dispatch off of
1031 ;;; the leaf to determine if a special action is appropriate.
1032 (defun delete-ref (ref)
1033 (declare (type ref ref))
1034 (let* ((leaf (ref-leaf ref))
1035 (refs (delq ref (leaf-refs leaf))))
1036 (setf (leaf-refs leaf) refs)
1041 (delete-lambda-var leaf))
1043 (ecase (functional-kind leaf)
1044 ((nil :let :mv-let :assignment :escape :cleanup)
1045 (aver (null (functional-entry-fun leaf)))
1046 (delete-lambda leaf))
1048 (delete-lambda leaf))
1049 ((:deleted :zombie :optional))))
1051 (unless (eq (functional-kind leaf) :deleted)
1052 (delete-optional-dispatch leaf)))))
1055 (clambda (or (maybe-let-convert leaf)
1056 (maybe-convert-to-assignment leaf)))
1057 (lambda-var (reoptimize-lambda-var leaf))))
1060 (clambda (maybe-convert-to-assignment leaf))))))
1064 ;;; This function is called by people who delete nodes; it provides a
1065 ;;; way to indicate that the value of a lvar is no longer used. We
1066 ;;; null out the LVAR-DEST, set FLUSH-P in the blocks containing uses
1067 ;;; of LVAR and set COMPONENT-REOPTIMIZE.
1068 (defun flush-dest (lvar)
1069 (declare (type (or lvar null) lvar))
1071 (setf (lvar-dest lvar) nil)
1072 (flush-lvar-externally-checkable-type lvar)
1074 (let ((prev (node-prev use)))
1075 (let ((block (ctran-block prev)))
1076 (reoptimize-component (block-component block) t)
1077 (setf (block-attributep (block-flags block)
1078 flush-p type-asserted type-check)
1080 (setf (node-lvar use) nil))
1081 (setf (lvar-uses lvar) nil))
1084 (defun delete-dest (lvar)
1086 (let* ((dest (lvar-dest lvar))
1087 (prev (node-prev dest)))
1088 (let ((block (ctran-block prev)))
1089 (unless (block-delete-p block)
1090 (mark-for-deletion block))))))
1092 ;;; Queue the block for deletion
1093 (defun delete-block-lazily (block)
1094 (declare (type cblock block))
1095 (unless (block-delete-p block)
1096 (setf (block-delete-p block) t)
1097 (push block (component-delete-blocks (block-component block)))))
1099 ;;; Do a graph walk backward from BLOCK, marking all predecessor
1100 ;;; blocks with the DELETE-P flag.
1101 (defun mark-for-deletion (block)
1102 (declare (type cblock block))
1103 (let* ((component (block-component block))
1104 (head (component-head component)))
1105 (labels ((helper (block)
1106 (delete-block-lazily block)
1107 (dolist (pred (block-pred block))
1108 (unless (or (block-delete-p pred)
1111 (unless (block-delete-p block)
1113 (setf (component-reanalyze component) t))))
1116 ;;; This function does what is necessary to eliminate the code in it
1117 ;;; from the IR1 representation. This involves unlinking it from its
1118 ;;; predecessors and successors and deleting various node-specific
1119 ;;; semantic information. BLOCK must be already removed from
1120 ;;; COMPONENT-DELETE-BLOCKS.
1121 (defun delete-block (block &optional silent)
1122 (declare (type cblock block))
1123 (aver (block-component block)) ; else block is already deleted!
1124 #!+high-security (aver (not (memq block (component-delete-blocks (block-component block)))))
1126 (note-block-deletion block))
1127 (setf (block-delete-p block) t)
1129 (dolist (b (block-pred block))
1130 (unlink-blocks b block)
1131 ;; In bug 147 the almost-all-blocks-have-a-successor invariant was
1132 ;; broken when successors were deleted without setting the
1133 ;; BLOCK-DELETE-P flags of their predececessors. Make sure that
1134 ;; doesn't happen again.
1135 (aver (not (and (null (block-succ b))
1136 (not (block-delete-p b))
1137 (not (eq b (component-head (block-component b))))))))
1138 (dolist (b (block-succ block))
1139 (unlink-blocks block b))
1141 (do-nodes-carefully (node block)
1142 (when (valued-node-p node)
1143 (delete-lvar-use node))
1145 (ref (delete-ref node))
1146 (cif (flush-dest (if-test node)))
1147 ;; The next two cases serve to maintain the invariant that a LET
1148 ;; always has a well-formed COMBINATION, REF and BIND. We delete
1149 ;; the lambda whenever we delete any of these, but we must be
1150 ;; careful that this LET has not already been partially deleted.
1152 (when (and (eq (basic-combination-kind node) :local)
1153 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
1154 (lvar-uses (basic-combination-fun node)))
1155 (let ((fun (combination-lambda node)))
1156 ;; If our REF was the second-to-last ref, and has been
1157 ;; deleted, then FUN may be a LET for some other
1159 (when (and (functional-letlike-p fun)
1160 (eq (let-combination fun) node))
1161 (delete-lambda fun))))
1162 (flush-dest (basic-combination-fun node))
1163 (dolist (arg (basic-combination-args node))
1164 (when arg (flush-dest arg))))
1166 (let ((lambda (bind-lambda node)))
1167 (unless (eq (functional-kind lambda) :deleted)
1168 (delete-lambda lambda))))
1170 (let ((value (exit-value node))
1171 (entry (exit-entry node)))
1175 (setf (entry-exits entry)
1176 (delq node (entry-exits entry))))))
1178 (dolist (exit (entry-exits node))
1179 (mark-for-deletion (node-block exit)))
1180 (let ((home (node-home-lambda node)))
1181 (setf (lambda-entries home) (delq node (lambda-entries home)))))
1183 (flush-dest (return-result node))
1184 (delete-return node))
1186 (flush-dest (set-value node))
1187 (let ((var (set-var node)))
1188 (setf (basic-var-sets var)
1189 (delete node (basic-var-sets var)))))
1191 (flush-dest (cast-value node)))))
1193 (remove-from-dfo block)
1196 ;;; Do stuff to indicate that the return node NODE is being deleted.
1197 (defun delete-return (node)
1198 (declare (type creturn node))
1199 (let* ((fun (return-lambda node))
1200 (tail-set (lambda-tail-set fun)))
1201 (aver (lambda-return fun))
1202 (setf (lambda-return fun) nil)
1203 (when (and tail-set (not (find-if #'lambda-return
1204 (tail-set-funs tail-set))))
1205 (setf (tail-set-type tail-set) *empty-type*)))
1208 ;;; If any of the VARS in FUN was never referenced and was not
1209 ;;; declared IGNORE, then complain.
1210 (defun note-unreferenced-vars (fun)
1211 (declare (type clambda fun))
1212 (dolist (var (lambda-vars fun))
1213 (unless (or (leaf-ever-used var)
1214 (lambda-var-ignorep var))
1215 (let ((*compiler-error-context* (lambda-bind fun)))
1216 (unless (policy *compiler-error-context* (= inhibit-warnings 3))
1217 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
1218 ;; requires this to be no more than a STYLE-WARNING.
1220 (compiler-style-warn "The variable ~S is defined but never used."
1221 (leaf-debug-name var))
1222 ;; There's no reason to accept this kind of equivocation
1223 ;; when compiling our own code, though.
1225 (warn "The variable ~S is defined but never used."
1226 (leaf-debug-name var)))
1227 (setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
1230 (defvar *deletion-ignored-objects* '(t nil))
1232 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
1233 ;;; our recursion so that we don't get lost in circular structures. We
1234 ;;; ignore the car of forms if they are a symbol (to prevent confusing
1235 ;;; function referencess with variables), and we also ignore anything
1237 (defun present-in-form (obj form depth)
1238 (declare (type (integer 0 20) depth))
1239 (cond ((= depth 20) nil)
1243 (let ((first (car form))
1245 (if (member first '(quote function))
1247 (or (and (not (symbolp first))
1248 (present-in-form obj first depth))
1249 (do ((l (cdr form) (cdr l))
1251 ((or (atom l) (> n 100))
1253 (declare (fixnum n))
1254 (when (present-in-form obj (car l) depth)
1257 ;;; This function is called on a block immediately before we delete
1258 ;;; it. We check to see whether any of the code about to die appeared
1259 ;;; in the original source, and emit a note if so.
1261 ;;; If the block was in a lambda is now deleted, then we ignore the
1262 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
1263 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
1264 ;;; reasonable for a function to not return, and there is a different
1265 ;;; note for that case anyway.
1267 ;;; If the actual source is an atom, then we use a bunch of heuristics
1268 ;;; to guess whether this reference really appeared in the original
1270 ;;; -- If a symbol, it must be interned and not a keyword.
1271 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
1272 ;;; or a character.)
1273 ;;; -- The atom must be "present" in the original source form, and
1274 ;;; present in all intervening actual source forms.
1275 (defun note-block-deletion (block)
1276 (let ((home (block-home-lambda block)))
1277 (unless (eq (functional-kind home) :deleted)
1278 (do-nodes (node nil block)
1279 (let* ((path (node-source-path node))
1280 (first (first path)))
1281 (when (or (eq first 'original-source-start)
1283 (or (not (symbolp first))
1284 (let ((pkg (symbol-package first)))
1286 (not (eq pkg (symbol-package :end))))))
1287 (not (member first *deletion-ignored-objects*))
1288 (not (typep first '(or fixnum character)))
1290 (present-in-form first x 0))
1291 (source-path-forms path))
1292 (present-in-form first (find-original-source path)
1294 (unless (return-p node)
1295 (let ((*compiler-error-context* node))
1296 (compiler-notify 'code-deletion-note
1297 :format-control "deleting unreachable code"
1298 :format-arguments nil)))
1302 ;;; Delete a node from a block, deleting the block if there are no
1303 ;;; nodes left. We remove the node from the uses of its LVAR.
1305 ;;; If the node is the last node, there must be exactly one successor.
1306 ;;; We link all of our precedessors to the successor and unlink the
1307 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1308 ;;; left, and the block is a successor of itself, then we replace the
1309 ;;; only node with a degenerate exit node. This provides a way to
1310 ;;; represent the bodyless infinite loop, given the prohibition on
1311 ;;; empty blocks in IR1.
1312 (defun unlink-node (node)
1313 (declare (type node node))
1314 (when (valued-node-p node)
1315 (delete-lvar-use node))
1317 (let* ((ctran (node-next node))
1318 (next (and ctran (ctran-next ctran)))
1319 (prev (node-prev node))
1320 (block (ctran-block prev))
1321 (prev-kind (ctran-kind prev))
1322 (last (block-last block)))
1324 (setf (block-type-asserted block) t)
1325 (setf (block-test-modified block) t)
1327 (cond ((or (eq prev-kind :inside-block)
1328 (and (eq prev-kind :block-start)
1329 (not (eq node last))))
1330 (cond ((eq node last)
1331 (setf (block-last block) (ctran-use prev))
1332 (setf (node-next (ctran-use prev)) nil))
1334 (setf (ctran-next prev) next)
1335 (setf (node-prev next) prev)
1336 (when (if-p next) ; AOP wanted
1337 (reoptimize-lvar (if-test next)))))
1338 (setf (node-prev node) nil)
1341 (aver (eq prev-kind :block-start))
1342 (aver (eq node last))
1343 (let* ((succ (block-succ block))
1344 (next (first succ)))
1345 (aver (singleton-p succ))
1347 ((eq block (first succ))
1348 (with-ir1-environment-from-node node
1349 (let ((exit (make-exit)))
1350 (setf (ctran-next prev) nil)
1351 (link-node-to-previous-ctran exit prev)
1352 (setf (block-last block) exit)))
1353 (setf (node-prev node) nil)
1356 (aver (eq (block-start-cleanup block)
1357 (block-end-cleanup block)))
1358 (unlink-blocks block next)
1359 (dolist (pred (block-pred block))
1360 (change-block-successor pred block next))
1361 (when (block-delete-p block)
1362 (let ((component (block-component block)))
1363 (setf (component-delete-blocks component)
1364 (delq block (component-delete-blocks component)))))
1365 (remove-from-dfo block)
1366 (setf (block-delete-p block) t)
1367 (setf (node-prev node) nil)
1370 ;;; Return true if CTRAN has been deleted, false if it is still a valid
1372 (defun ctran-deleted-p (ctran)
1373 (declare (type ctran ctran))
1374 (let ((block (ctran-block ctran)))
1375 (or (not (block-component block))
1376 (block-delete-p block))))
1378 ;;; Return true if NODE has been deleted, false if it is still a valid
1380 (defun node-deleted (node)
1381 (declare (type node node))
1382 (let ((prev (node-prev node)))
1384 (ctran-deleted-p prev))))
1386 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1387 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1388 ;;; triggered by deletion.
1389 (defun delete-component (component)
1390 (declare (type component component))
1391 (aver (null (component-new-functionals component)))
1392 (setf (component-kind component) :deleted)
1393 (do-blocks (block component)
1394 (delete-block-lazily block))
1395 (dolist (fun (component-lambdas component))
1396 (unless (eq (functional-kind fun) :deleted)
1397 (setf (functional-kind fun) nil)
1398 (setf (functional-entry-fun fun) nil)
1399 (setf (leaf-refs fun) nil)
1400 (delete-functional fun)))
1401 (clean-component component)
1404 ;;; Remove all pending blocks to be deleted. Return the nearest live
1405 ;;; block after or equal to BLOCK.
1406 (defun clean-component (component &optional block)
1407 (loop while (component-delete-blocks component)
1408 ;; actual deletion of a block may queue new blocks
1409 do (let ((current (pop (component-delete-blocks component))))
1410 (when (eq block current)
1411 (setq block (block-next block)))
1412 (delete-block current)))
1415 ;;; Convert code of the form
1416 ;;; (FOO ... (FUN ...) ...)
1418 ;;; (FOO ... ... ...).
1419 ;;; In other words, replace the function combination FUN by its
1420 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1421 ;;; to blow out of whatever transform called this. Note, as the number
1422 ;;; of arguments changes, the transform must be prepared to return a
1423 ;;; lambda with a new lambda-list with the correct number of
1425 (defun extract-fun-args (lvar fun num-args)
1427 "If LVAR is a call to FUN with NUM-ARGS args, change those arguments
1428 to feed directly to the LVAR-DEST of LVAR, which must be a
1430 (declare (type lvar lvar)
1432 (type index num-args))
1433 (let ((outside (lvar-dest lvar))
1434 (inside (lvar-uses lvar)))
1435 (aver (combination-p outside))
1436 (unless (combination-p inside)
1437 (give-up-ir1-transform))
1438 (let ((inside-fun (combination-fun inside)))
1439 (unless (eq (lvar-fun-name inside-fun) fun)
1440 (give-up-ir1-transform))
1441 (let ((inside-args (combination-args inside)))
1442 (unless (= (length inside-args) num-args)
1443 (give-up-ir1-transform))
1444 (let* ((outside-args (combination-args outside))
1445 (arg-position (position lvar outside-args))
1446 (before-args (subseq outside-args 0 arg-position))
1447 (after-args (subseq outside-args (1+ arg-position))))
1448 (dolist (arg inside-args)
1449 (setf (lvar-dest arg) outside)
1450 (flush-lvar-externally-checkable-type arg))
1451 (setf (combination-args inside) nil)
1452 (setf (combination-args outside)
1453 (append before-args inside-args after-args))
1454 (change-ref-leaf (lvar-uses inside-fun)
1455 (find-free-fun 'list "???"))
1456 (setf (combination-fun-info inside) (info :function :info 'list)
1457 (combination-kind inside) :known)
1458 (setf (node-derived-type inside) *wild-type*)
1462 (defun flush-combination (combination)
1463 (declare (type combination combination))
1464 (flush-dest (combination-fun combination))
1465 (dolist (arg (combination-args combination))
1467 (unlink-node combination)
1473 ;;; Change the LEAF that a REF refers to.
1474 (defun change-ref-leaf (ref leaf)
1475 (declare (type ref ref) (type leaf leaf))
1476 (unless (eq (ref-leaf ref) leaf)
1477 (push ref (leaf-refs leaf))
1479 (setf (ref-leaf ref) leaf)
1480 (setf (leaf-ever-used leaf) t)
1481 (let* ((ltype (leaf-type leaf))
1482 (vltype (make-single-value-type ltype)))
1483 (if (let* ((lvar (node-lvar ref))
1484 (dest (and lvar (lvar-dest lvar))))
1485 (and (basic-combination-p dest)
1486 (eq lvar (basic-combination-fun dest))
1487 (csubtypep ltype (specifier-type 'function))))
1488 (setf (node-derived-type ref) vltype)
1489 (derive-node-type ref vltype)))
1490 (reoptimize-lvar (node-lvar ref)))
1493 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1494 (defun substitute-leaf (new-leaf old-leaf)
1495 (declare (type leaf new-leaf old-leaf))
1496 (dolist (ref (leaf-refs old-leaf))
1497 (change-ref-leaf ref new-leaf))
1500 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1501 ;;; whether to substitute
1502 (defun substitute-leaf-if (test new-leaf old-leaf)
1503 (declare (type leaf new-leaf old-leaf) (type function test))
1504 (dolist (ref (leaf-refs old-leaf))
1505 (when (funcall test ref)
1506 (change-ref-leaf ref new-leaf)))
1509 ;;; Return a LEAF which represents the specified constant object. If
1510 ;;; the object is not in *CONSTANTS*, then we create a new constant
1511 ;;; LEAF and enter it.
1512 (defun find-constant (object)
1514 ;; FIXME: What is the significance of this test? ("things
1515 ;; that are worth uniquifying"?)
1516 '(or symbol number character instance))
1517 (or (gethash object *constants*)
1518 (setf (gethash object *constants*)
1519 (make-constant :value object
1520 :%source-name '.anonymous.
1521 :type (ctype-of object)
1522 :where-from :defined)))
1523 (make-constant :value object
1524 :%source-name '.anonymous.
1525 :type (ctype-of object)
1526 :where-from :defined)))
1528 ;;; Return true if VAR would have to be closed over if environment
1529 ;;; analysis ran now (i.e. if there are any uses that have a different
1530 ;;; home lambda than VAR's home.)
1531 (defun closure-var-p (var)
1532 (declare (type lambda-var var))
1533 (let ((home (lambda-var-home var)))
1534 (cond ((eq (functional-kind home) :deleted)
1536 (t (let ((home (lambda-home home)))
1539 :key #'node-home-lambda
1541 (or (frob (leaf-refs var))
1542 (frob (basic-var-sets var)))))))))
1544 ;;; If there is a non-local exit noted in ENTRY's environment that
1545 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1546 (defun find-nlx-info (exit)
1547 (declare (type exit exit))
1548 (let* ((entry (exit-entry exit))
1549 (cleanup (entry-cleanup entry))
1550 (block (first (block-succ (node-block exit)))))
1551 (dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
1552 (when (and (eq (nlx-info-block nlx) block)
1553 (eq (nlx-info-cleanup nlx) cleanup))
1556 (defun nlx-info-lvar (nlx)
1557 (declare (type nlx-info nlx))
1558 (node-lvar (block-last (nlx-info-target nlx))))
1560 ;;;; functional hackery
1562 (declaim (ftype (sfunction (functional) clambda) main-entry))
1563 (defun main-entry (functional)
1564 (etypecase functional
1565 (clambda functional)
1567 (optional-dispatch-main-entry functional))))
1569 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1570 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1571 ;;; optional with null default and no SUPPLIED-P. There must be a
1572 ;;; &REST arg with no references.
1573 (declaim (ftype (sfunction (functional) boolean) looks-like-an-mv-bind))
1574 (defun looks-like-an-mv-bind (functional)
1575 (and (optional-dispatch-p functional)
1576 (do ((arg (optional-dispatch-arglist functional) (cdr arg)))
1578 (let ((info (lambda-var-arg-info (car arg))))
1579 (unless info (return nil))
1580 (case (arg-info-kind info)
1582 (when (or (arg-info-supplied-p info) (arg-info-default info))
1585 (return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
1589 ;;; Return true if function is an external entry point. This is true
1590 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1591 ;;; (:TOPLEVEL kind.)
1593 (declare (type functional fun))
1594 (not (null (member (functional-kind fun) '(:external :toplevel)))))
1596 ;;; If LVAR's only use is a non-notinline global function reference,
1597 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1598 ;;; is true, then we don't care if the leaf is NOTINLINE.
1599 (defun lvar-fun-name (lvar &optional notinline-ok)
1600 (declare (type lvar lvar))
1601 (let ((use (lvar-uses lvar)))
1603 (let ((leaf (ref-leaf use)))
1604 (if (and (global-var-p leaf)
1605 (eq (global-var-kind leaf) :global-function)
1606 (or (not (defined-fun-p leaf))
1607 (not (eq (defined-fun-inlinep leaf) :notinline))
1609 (leaf-source-name leaf)
1613 ;;; Return the source name of a combination. (This is an idiom
1614 ;;; which was used in CMU CL. I gather it always works. -- WHN)
1615 (defun combination-fun-source-name (combination)
1616 (let ((ref (lvar-uses (combination-fun combination))))
1617 (leaf-source-name (ref-leaf ref))))
1619 ;;; Return the COMBINATION node that is the call to the LET FUN.
1620 (defun let-combination (fun)
1621 (declare (type clambda fun))
1622 (aver (functional-letlike-p fun))
1623 (lvar-dest (node-lvar (first (leaf-refs fun)))))
1625 ;;; Return the initial value lvar for a LET variable, or NIL if there
1627 (defun let-var-initial-value (var)
1628 (declare (type lambda-var var))
1629 (let ((fun (lambda-var-home var)))
1630 (elt (combination-args (let-combination fun))
1631 (position-or-lose var (lambda-vars fun)))))
1633 ;;; Return the LAMBDA that is called by the local CALL.
1634 (defun combination-lambda (call)
1635 (declare (type basic-combination call))
1636 (aver (eq (basic-combination-kind call) :local))
1637 (ref-leaf (lvar-uses (basic-combination-fun call))))
1639 (defvar *inline-expansion-limit* 200
1641 "an upper limit on the number of inline function calls that will be expanded
1642 in any given code object (single function or block compilation)")
1644 ;;; Check whether NODE's component has exceeded its inline expansion
1645 ;;; limit, and warn if so, returning NIL.
1646 (defun inline-expansion-ok (node)
1647 (let ((expanded (incf (component-inline-expansions
1649 (node-block node))))))
1650 (cond ((> expanded *inline-expansion-limit*) nil)
1651 ((= expanded *inline-expansion-limit*)
1652 ;; FIXME: If the objective is to stop the recursive
1653 ;; expansion of inline functions, wouldn't it be more
1654 ;; correct to look back through surrounding expansions
1655 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1656 ;; possibly stored elsewhere too) and suppress expansion
1657 ;; and print this warning when the function being proposed
1658 ;; for inline expansion is found there? (I don't like the
1659 ;; arbitrary numerical limit in principle, and I think
1660 ;; it'll be a nuisance in practice if we ever want the
1661 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1662 ;; arbitrarily huge blocks of code. -- WHN)
1663 (let ((*compiler-error-context* node))
1664 (compiler-notify "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1665 probably trying to~% ~
1666 inline a recursive function."
1667 *inline-expansion-limit*))
1671 ;;; Make sure that FUNCTIONAL is not let-converted or deleted.
1672 (defun assure-functional-live-p (functional)
1673 (declare (type functional functional))
1675 ;; looks LET-converted
1676 (functional-somewhat-letlike-p functional)
1677 ;; It's possible for a LET-converted function to end up
1678 ;; deleted later. In that case, for the purposes of this
1679 ;; analysis, it is LET-converted: LET-converted functionals
1680 ;; are too badly trashed to expand them inline, and deleted
1681 ;; LET-converted functionals are even worse.
1682 (memq (functional-kind functional) '(:deleted :zombie))))
1683 (throw 'locall-already-let-converted functional)))
1685 (defun call-full-like-p (call)
1686 (declare (type combination call))
1687 (let ((kind (basic-combination-kind call)))
1689 (and (eq kind :known)
1690 (let ((info (basic-combination-fun-info call)))
1692 (not (fun-info-ir2-convert info))
1693 (dolist (template (fun-info-templates info) t)
1694 (when (eq (template-ltn-policy template) :fast-safe)
1695 (multiple-value-bind (val win)
1696 (valid-fun-use call (template-type template))
1697 (when (or val (not win)) (return nil)))))))))))
1701 ;;; Apply a function to some arguments, returning a list of the values
1702 ;;; resulting of the evaluation. If an error is signalled during the
1703 ;;; application, then we produce a warning message using WARN-FUN and
1704 ;;; return NIL as our second value to indicate this. NODE is used as
1705 ;;; the error context for any error message, and CONTEXT is a string
1706 ;;; that is spliced into the warning.
1707 (declaim (ftype (sfunction ((or symbol function) list node function string)
1708 (values list boolean))
1710 (defun careful-call (function args node warn-fun context)
1712 (multiple-value-list
1713 (handler-case (apply function args)
1715 (let ((*compiler-error-context* node))
1716 (funcall warn-fun "Lisp error during ~A:~%~A" context condition)
1717 (return-from careful-call (values nil nil))))))
1720 ;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
1723 ((deffrob (basic careful compiler transform)
1725 (defun ,careful (specifier)
1726 (handler-case (,basic specifier)
1727 (sb!kernel::arg-count-error (condition)
1728 (values nil (list (format nil "~A" condition))))
1729 (simple-error (condition)
1730 (values nil (list* (simple-condition-format-control condition)
1731 (simple-condition-format-arguments condition))))))
1732 (defun ,compiler (specifier)
1733 (multiple-value-bind (type error-args) (,careful specifier)
1735 (apply #'compiler-error error-args))))
1736 (defun ,transform (specifier)
1737 (multiple-value-bind (type error-args) (,careful specifier)
1739 (apply #'give-up-ir1-transform
1741 (deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type)
1742 (deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type))
1745 ;;;; utilities used at run-time for parsing &KEY args in IR1
1747 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1748 ;;; the lvar for the value of the &KEY argument KEY in the list of
1749 ;;; lvars ARGS. It returns the lvar if the keyword is present, or NIL
1750 ;;; otherwise. The legality and constantness of the keywords should
1751 ;;; already have been checked.
1752 (declaim (ftype (sfunction (list keyword) (or lvar null))
1754 (defun find-keyword-lvar (args key)
1755 (do ((arg args (cddr arg)))
1757 (when (eq (lvar-value (first arg)) key)
1758 (return (second arg)))))
1760 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1761 ;;; verify that alternating lvars in ARGS are constant and that there
1762 ;;; is an even number of args.
1763 (declaim (ftype (sfunction (list) boolean) check-key-args-constant))
1764 (defun check-key-args-constant (args)
1765 (do ((arg args (cddr arg)))
1767 (unless (and (rest arg)
1768 (constant-lvar-p (first arg)))
1771 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1772 ;;; verify that the list of lvars ARGS is a well-formed &KEY arglist
1773 ;;; and that only keywords present in the list KEYS are supplied.
1774 (declaim (ftype (sfunction (list list) boolean) check-transform-keys))
1775 (defun check-transform-keys (args keys)
1776 (and (check-key-args-constant args)
1777 (do ((arg args (cddr arg)))
1779 (unless (member (lvar-value (first arg)) keys)
1784 ;;; Called by the expansion of the EVENT macro.
1785 (declaim (ftype (sfunction (event-info (or node null)) *) %event))
1786 (defun %event (info node)
1787 (incf (event-info-count info))
1788 (when (and (>= (event-info-level info) *event-note-threshold*)
1789 (policy (or node *lexenv*)
1790 (= inhibit-warnings 0)))
1791 (let ((*compiler-error-context* node))
1792 (compiler-notify (event-info-description info))))
1794 (let ((action (event-info-action info)))
1795 (when action (funcall action node))))
1798 (defun make-cast (value type policy)
1799 (declare (type lvar value)
1801 (type policy policy))
1802 (%make-cast :asserted-type type
1803 :type-to-check (maybe-weaken-check type policy)
1805 :derived-type (coerce-to-values type)))
1807 (defun cast-type-check (cast)
1808 (declare (type cast cast))
1809 (when (cast-reoptimize cast)
1810 (ir1-optimize-cast cast t))
1811 (cast-%type-check cast))
1813 (defun note-single-valuified-lvar (lvar)
1814 (declare (type (or lvar null) lvar))
1816 (let ((use (lvar-uses lvar)))
1818 (let ((leaf (ref-leaf use)))
1819 (when (and (lambda-var-p leaf)
1820 (null (rest (leaf-refs leaf))))
1821 (reoptimize-lambda-var leaf))))
1822 ((or (listp use) (combination-p use))
1823 (do-uses (node lvar)
1824 (setf (node-reoptimize node) t)
1825 (setf (block-reoptimize (node-block node)) t)
1826 (reoptimize-component (node-component node) :maybe)))))))