1 ;;;; This file implements the IR1 optimization phase of the compiler.
2 ;;;; IR1 optimization is a grab-bag of optimizations that don't make
3 ;;;; major changes to the block-level control flow and don't use flow
4 ;;;; analysis. These optimizations can mostly be classified as
5 ;;;; "meta-evaluation", but there is a sizable top-down component as
8 ;;;; This software is part of the SBCL system. See the README file for
11 ;;;; This software is derived from the CMU CL system, which was
12 ;;;; written at Carnegie Mellon University and released into the
13 ;;;; public domain. The software is in the public domain and is
14 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
15 ;;;; files for more information.
19 ;;;; interface for obtaining results of constant folding
21 ;;; Return true for an LVAR whose sole use is a reference to a
23 (defun constant-lvar-p (thing)
24 (declare (type (or lvar null
) thing
))
26 (let ((use (principal-lvar-use thing
)))
27 (and (ref-p use
) (constant-p (ref-leaf use
))))))
29 ;;; Return the constant value for an LVAR whose only use is a constant
31 (declaim (ftype (function (lvar) t
) lvar-value
))
32 (defun lvar-value (lvar)
33 (let ((use (principal-lvar-use lvar
)))
34 (constant-value (ref-leaf use
))))
36 ;;;; interface for obtaining results of type inference
38 ;;; Our best guess for the type of this lvar's value. Note that this
39 ;;; may be VALUES or FUNCTION type, which cannot be passed as an
40 ;;; argument to the normal type operations. See LVAR-TYPE.
42 ;;; The result value is cached in the LVAR-%DERIVED-TYPE slot. If the
43 ;;; slot is true, just return that value, otherwise recompute and
44 ;;; stash the value there.
45 #!-sb-fluid
(declaim (inline lvar-derived-type
))
46 (defun lvar-derived-type (lvar)
47 (declare (type lvar lvar
))
48 (or (lvar-%derived-type lvar
)
49 (setf (lvar-%derived-type lvar
)
50 (%lvar-derived-type lvar
))))
51 (defun %lvar-derived-type
(lvar)
52 (declare (type lvar lvar
))
53 (let ((uses (lvar-uses lvar
)))
54 (cond ((null uses
) *empty-type
*)
56 (do ((res (node-derived-type (first uses
))
57 (values-type-union (node-derived-type (first current
))
59 (current (rest uses
) (rest current
)))
60 ((or (null current
) (eq res
*wild-type
*))
63 (node-derived-type uses
)))))
65 ;;; Return the derived type for LVAR's first value. This is guaranteed
66 ;;; not to be a VALUES or FUNCTION type.
67 (declaim (ftype (sfunction (lvar) ctype
) lvar-type
))
68 (defun lvar-type (lvar)
69 (single-value-type (lvar-derived-type lvar
)))
71 ;;; If LVAR is an argument of a function, return a type which the
72 ;;; function checks LVAR for.
73 #!-sb-fluid
(declaim (inline lvar-externally-checkable-type
))
74 (defun lvar-externally-checkable-type (lvar)
75 (or (lvar-%externally-checkable-type lvar
)
76 (%lvar-%externally-checkable-type lvar
)))
77 (defun %lvar-%externally-checkable-type
(lvar)
78 (declare (type lvar lvar
))
79 (let ((dest (lvar-dest lvar
)))
80 (if (not (and dest
(combination-p dest
)))
81 ;; TODO: MV-COMBINATION
82 (setf (lvar-%externally-checkable-type lvar
) *wild-type
*)
83 (let* ((fun (combination-fun dest
))
84 (args (combination-args dest
))
85 (fun-type (lvar-type fun
)))
86 (setf (lvar-%externally-checkable-type fun
) *wild-type
*)
87 (if (or (not (call-full-like-p dest
))
88 (not (fun-type-p fun-type
))
89 ;; FUN-TYPE might be (AND FUNCTION (SATISFIES ...)).
90 (fun-type-wild-args fun-type
))
93 (setf (lvar-%externally-checkable-type arg
)
95 (map-combination-args-and-types
97 (setf (lvar-%externally-checkable-type arg
)
98 (acond ((lvar-%externally-checkable-type arg
)
99 (values-type-intersection
100 it
(coerce-to-values type
)))
101 (t (coerce-to-values type
)))))
103 (lvar-%externally-checkable-type lvar
))
104 #!-sb-fluid
(declaim (inline flush-lvar-externally-checkable-type
))
105 (defun flush-lvar-externally-checkable-type (lvar)
106 (declare (type lvar lvar
))
107 (setf (lvar-%externally-checkable-type lvar
) nil
))
109 ;;;; interface routines used by optimizers
111 (declaim (inline reoptimize-component
))
112 (defun reoptimize-component (component kind
)
113 (declare (type component component
)
114 (type (member nil
:maybe t
) kind
))
116 (unless (eq (component-reoptimize component
) t
)
117 (setf (component-reoptimize component
) kind
)))
119 ;;; This function is called by optimizers to indicate that something
120 ;;; interesting has happened to the value of LVAR. Optimizers must
121 ;;; make sure that they don't call for reoptimization when nothing has
122 ;;; happened, since optimization will fail to terminate.
124 ;;; We clear any cached type for the lvar and set the reoptimize flags
125 ;;; on everything in sight.
126 (defun reoptimize-lvar (lvar)
127 (declare (type (or lvar null
) lvar
))
129 (setf (lvar-%derived-type lvar
) nil
)
130 (let ((dest (lvar-dest lvar
)))
132 (setf (lvar-reoptimize lvar
) t
)
133 (setf (node-reoptimize dest
) t
)
134 (binding* (;; Since this may be called during IR1 conversion,
135 ;; PREV may be missing.
136 (prev (node-prev dest
) :exit-if-null
)
137 (block (ctran-block prev
))
138 (component (block-component block
)))
139 (when (typep dest
'cif
)
140 (setf (block-test-modified block
) t
))
141 (setf (block-reoptimize block
) t
)
142 (reoptimize-component component
:maybe
))))
144 (setf (block-type-check (node-block node
)) t
)))
147 (defun reoptimize-lvar-uses (lvar)
148 (declare (type lvar lvar
))
150 (setf (node-reoptimize use
) t
)
151 (setf (block-reoptimize (node-block use
)) t
)
152 (reoptimize-component (node-component use
) :maybe
)))
154 ;;; Annotate NODE to indicate that its result has been proven to be
155 ;;; TYPEP to RTYPE. After IR1 conversion has happened, this is the
156 ;;; only correct way to supply information discovered about a node's
157 ;;; type. If you screw with the NODE-DERIVED-TYPE directly, then
158 ;;; information may be lost and reoptimization may not happen.
160 ;;; What we do is intersect RTYPE with NODE's DERIVED-TYPE. If the
161 ;;; intersection is different from the old type, then we do a
162 ;;; REOPTIMIZE-LVAR on the NODE-LVAR.
163 (defun derive-node-type (node rtype
)
164 (declare (type valued-node node
) (type ctype rtype
))
165 (let ((node-type (node-derived-type node
)))
166 (unless (eq node-type rtype
)
167 (let ((int (values-type-intersection node-type rtype
))
168 (lvar (node-lvar node
)))
169 (when (type/= node-type int
)
170 (when (and *check-consistency
*
171 (eq int
*empty-type
*)
172 (not (eq rtype
*empty-type
*)))
173 (let ((*compiler-error-context
* node
))
175 "New inferred type ~S conflicts with old type:~
176 ~% ~S~%*** possible internal error? Please report this."
177 (type-specifier rtype
) (type-specifier node-type
))))
178 (setf (node-derived-type node
) int
)
179 ;; If the new type consists of only one object, replace the
180 ;; node with a constant reference.
181 (when (and (ref-p node
)
182 (lambda-var-p (ref-leaf node
)))
183 (let ((type (single-value-type int
)))
184 (when (and (member-type-p type
)
185 (eql 1 (member-type-size type
)))
186 (change-ref-leaf node
(find-constant
187 (first (member-type-members type
)))))))
188 (reoptimize-lvar lvar
)))))
191 ;;; This is similar to DERIVE-NODE-TYPE, but asserts that it is an
192 ;;; error for LVAR's value not to be TYPEP to TYPE. We implement it
193 ;;; splitting off DEST a new CAST node; old LVAR will deliver values
194 ;;; to CAST. If we improve the assertion, we set TYPE-CHECK and
195 ;;; TYPE-ASSERTED to guarantee that the new assertion will be checked.
196 (defun assert-lvar-type (lvar type policy
)
197 (declare (type lvar lvar
) (type ctype type
))
198 (unless (values-subtypep (lvar-derived-type lvar
) type
)
199 (let ((internal-lvar (make-lvar))
200 (dest (lvar-dest lvar
)))
201 (substitute-lvar internal-lvar lvar
)
202 (let ((cast (insert-cast-before dest lvar type policy
)))
203 (use-lvar cast internal-lvar
))))
209 ;;; Do one forward pass over COMPONENT, deleting unreachable blocks
210 ;;; and doing IR1 optimizations. We can ignore all blocks that don't
211 ;;; have the REOPTIMIZE flag set. If COMPONENT-REOPTIMIZE is true when
212 ;;; we are done, then another iteration would be beneficial.
213 (defun ir1-optimize (component fastp
)
214 (declare (type component component
))
215 (setf (component-reoptimize component
) nil
)
216 (loop with block
= (block-next (component-head component
))
217 with tail
= (component-tail component
)
218 for last-block
= block
219 until
(eq block tail
)
221 ;; We delete blocks when there is either no predecessor or the
222 ;; block is in a lambda that has been deleted. These blocks
223 ;; would eventually be deleted by DFO recomputation, but doing
224 ;; it here immediately makes the effect available to IR1
226 ((or (block-delete-p block
)
227 (null (block-pred block
)))
228 (delete-block-lazily block
)
229 (setq block
(clean-component component block
)))
230 ((eq (functional-kind (block-home-lambda block
)) :deleted
)
231 ;; Preserve the BLOCK-SUCC invariant that almost every block has
232 ;; one successor (and a block with DELETE-P set is an acceptable
234 (mark-for-deletion block
)
235 (setq block
(clean-component component block
)))
238 (let ((succ (block-succ block
)))
239 (unless (singleton-p succ
)
242 (let ((last (block-last block
)))
245 (flush-dest (if-test last
))
246 (when (unlink-node last
)
249 (when (maybe-delete-exit last
)
252 (unless (join-successor-if-possible block
)
255 (when (and (not fastp
) (block-reoptimize block
) (block-component block
))
256 (aver (not (block-delete-p block
)))
257 (ir1-optimize-block block
))
259 (cond ((and (block-delete-p block
) (block-component block
))
260 (setq block
(clean-component component block
)))
261 ((and (block-flush-p block
) (block-component block
))
262 (flush-dead-code block
)))))
263 do
(when (eq block last-block
)
264 (setq block
(block-next block
))))
268 ;;; Loop over the nodes in BLOCK, acting on (and clearing) REOPTIMIZE
271 ;;; Note that although they are cleared here, REOPTIMIZE flags might
272 ;;; still be set upon return from this function, meaning that further
273 ;;; optimization is wanted (as a consequence of optimizations we did).
274 (defun ir1-optimize-block (block)
275 (declare (type cblock block
))
276 ;; We clear the node and block REOPTIMIZE flags before doing the
277 ;; optimization, not after. This ensures that the node or block will
278 ;; be reoptimized if necessary.
279 (setf (block-reoptimize block
) nil
)
280 (do-nodes (node nil block
:restart-p t
)
281 (when (node-reoptimize node
)
282 ;; As above, we clear the node REOPTIMIZE flag before optimizing.
283 (setf (node-reoptimize node
) nil
)
287 ;; With a COMBINATION, we call PROPAGATE-FUN-CHANGE whenever
288 ;; the function changes, and call IR1-OPTIMIZE-COMBINATION if
289 ;; any argument changes.
290 (ir1-optimize-combination node
))
292 (ir1-optimize-if node
))
294 ;; KLUDGE: We leave the NODE-OPTIMIZE flag set going into
295 ;; IR1-OPTIMIZE-RETURN, since IR1-OPTIMIZE-RETURN wants to
296 ;; clear the flag itself. -- WHN 2002-02-02, quoting original
298 (setf (node-reoptimize node
) t
)
299 (ir1-optimize-return node
))
301 (ir1-optimize-mv-combination node
))
303 ;; With an EXIT, we derive the node's type from the VALUE's
305 (let ((value (exit-value node
)))
307 (derive-node-type node
(lvar-derived-type value
)))))
309 (ir1-optimize-set node
))
311 (ir1-optimize-cast node
)))))
315 ;;; Try to join with a successor block. If we succeed, we return true,
317 (defun join-successor-if-possible (block)
318 (declare (type cblock block
))
319 (let ((next (first (block-succ block
))))
320 (when (block-start next
) ; NEXT is not an END-OF-COMPONENT marker
321 (cond ( ;; We cannot combine with a successor block if:
323 ;; the successor has more than one predecessor;
324 (rest (block-pred next
))
325 ;; the successor is the current block (infinite loop);
327 ;; the next block has a different cleanup, and thus
328 ;; we may want to insert cleanup code between the
329 ;; two blocks at some point;
330 (not (eq (block-end-cleanup block
)
331 (block-start-cleanup next
)))
332 ;; the next block has a different home lambda, and
333 ;; thus the control transfer is a non-local exit.
334 (not (eq (block-home-lambda block
)
335 (block-home-lambda next
)))
336 ;; Stack analysis phase wants ENTRY to start a block...
337 (entry-p (block-start-node next
))
338 (let ((last (block-last block
)))
339 (and (valued-node-p last
)
340 (awhen (node-lvar last
)
342 ;; ... and a DX-allocator to end a block.
343 (lvar-dynamic-extent it
)
344 ;; FIXME: This is a partial workaround for bug 303.
345 (consp (lvar-uses it
)))))))
348 (join-blocks block next
)
351 ;;; Join together two blocks. The code in BLOCK2 is moved into BLOCK1
352 ;;; and BLOCK2 is deleted from the DFO. We combine the optimize flags
353 ;;; for the two blocks so that any indicated optimization gets done.
354 (defun join-blocks (block1 block2
)
355 (declare (type cblock block1 block2
))
356 (let* ((last1 (block-last block1
))
357 (last2 (block-last block2
))
358 (succ (block-succ block2
))
359 (start2 (block-start block2
)))
360 (do ((ctran start2
(node-next (ctran-next ctran
))))
362 (setf (ctran-block ctran
) block1
))
364 (unlink-blocks block1 block2
)
366 (unlink-blocks block2 block
)
367 (link-blocks block1 block
))
369 (setf (ctran-kind start2
) :inside-block
)
370 (setf (node-next last1
) start2
)
371 (setf (ctran-use start2
) last1
)
372 (setf (block-last block1
) last2
))
374 (setf (block-flags block1
)
375 (attributes-union (block-flags block1
)
377 (block-attributes type-asserted test-modified
)))
379 (let ((next (block-next block2
))
380 (prev (block-prev block2
)))
381 (setf (block-next prev
) next
)
382 (setf (block-prev next
) prev
))
386 ;;; Delete any nodes in BLOCK whose value is unused and which have no
387 ;;; side effects. We can delete sets of lexical variables when the set
388 ;;; variable has no references.
389 (defun flush-dead-code (block)
390 (declare (type cblock block
))
391 (setf (block-flush-p block
) nil
)
392 (do-nodes-backwards (node lvar block
:restart-p t
)
399 (let ((kind (combination-kind node
))
400 (info (combination-fun-info node
)))
401 (when (and (eq kind
:known
) (fun-info-p info
))
402 (let ((attr (fun-info-attributes info
)))
403 (when (and (not (ir1-attributep attr call
))
404 ;; ### For now, don't delete potentially
405 ;; flushable calls when they have the CALL
406 ;; attribute. Someday we should look at the
407 ;; functional args to determine if they have
409 (if (policy node
(= safety
3))
410 (ir1-attributep attr flushable
)
411 (ir1-attributep attr unsafely-flushable
)))
412 (flush-combination node
))))))
414 (when (eq (basic-combination-kind node
) :local
)
415 (let ((fun (combination-lambda node
)))
416 (when (dolist (var (lambda-vars fun
) t
)
417 (when (or (leaf-refs var
)
418 (lambda-var-sets var
))
420 (flush-dest (first (basic-combination-args node
)))
423 (let ((value (exit-value node
)))
426 (setf (exit-value node
) nil
))))
428 (let ((var (set-var node
)))
429 (when (and (lambda-var-p var
)
430 (null (leaf-refs var
)))
431 (flush-dest (set-value node
))
432 (setf (basic-var-sets var
)
433 (delq node
(basic-var-sets var
)))
434 (unlink-node node
))))
436 (unless (cast-type-check node
)
437 (flush-dest (cast-value node
))
438 (unlink-node node
))))))
442 ;;;; local call return type propagation
444 ;;; This function is called on RETURN nodes that have their REOPTIMIZE
445 ;;; flag set. It iterates over the uses of the RESULT, looking for
446 ;;; interesting stuff to update the TAIL-SET. If a use isn't a local
447 ;;; call, then we union its type together with the types of other such
448 ;;; uses. We assign to the RETURN-RESULT-TYPE the intersection of this
449 ;;; type with the RESULT's asserted type. We can make this
450 ;;; intersection now (potentially before type checking) because this
451 ;;; assertion on the result will eventually be checked (if
454 ;;; We call MAYBE-CONVERT-TAIL-LOCAL-CALL on each local non-MV
455 ;;; combination, which may change the successor of the call to be the
456 ;;; called function, and if so, checks if the call can become an
457 ;;; assignment. If we convert to an assignment, we abort, since the
458 ;;; RETURN has been deleted.
459 (defun find-result-type (node)
460 (declare (type creturn node
))
461 (let ((result (return-result node
)))
462 (collect ((use-union *empty-type
* values-type-union
))
463 (do-uses (use result
)
464 (let ((use-home (node-home-lambda use
)))
465 (cond ((or (eq (functional-kind use-home
) :deleted
)
466 (block-delete-p (node-block use
))))
467 ((and (basic-combination-p use
)
468 (eq (basic-combination-kind use
) :local
))
469 (aver (eq (lambda-tail-set use-home
)
470 (lambda-tail-set (combination-lambda use
))))
471 (when (combination-p use
)
472 (when (nth-value 1 (maybe-convert-tail-local-call use
))
473 (return-from find-result-type t
))))
475 (use-union (node-derived-type use
))))))
477 ;; (values-type-intersection
478 ;; (continuation-asserted-type result) ; FIXME -- APD, 2002-01-26
482 (setf (return-result-type node
) int
))))
485 ;;; Do stuff to realize that something has changed about the value
486 ;;; delivered to a return node. Since we consider the return values of
487 ;;; all functions in the tail set to be equivalent, this amounts to
488 ;;; bringing the entire tail set up to date. We iterate over the
489 ;;; returns for all the functions in the tail set, reanalyzing them
490 ;;; all (not treating NODE specially.)
492 ;;; When we are done, we check whether the new type is different from
493 ;;; the old TAIL-SET-TYPE. If so, we set the type and also reoptimize
494 ;;; all the lvars for references to functions in the tail set. This
495 ;;; will cause IR1-OPTIMIZE-COMBINATION to derive the new type as the
496 ;;; results of the calls.
497 (defun ir1-optimize-return (node)
498 (declare (type creturn node
))
501 (let* ((tails (lambda-tail-set (return-lambda node
)))
502 (funs (tail-set-funs tails
)))
503 (collect ((res *empty-type
* values-type-union
))
505 (let ((return (lambda-return fun
)))
507 (when (node-reoptimize return
)
508 (setf (node-reoptimize return
) nil
)
509 (when (find-result-type return
)
511 (res (return-result-type return
)))))
513 (when (type/= (res) (tail-set-type tails
))
514 (setf (tail-set-type tails
) (res))
515 (dolist (fun (tail-set-funs tails
))
516 (dolist (ref (leaf-refs fun
))
517 (reoptimize-lvar (node-lvar ref
))))))))
523 ;;; If the test has multiple uses, replicate the node when possible.
524 ;;; Also check whether the predicate is known to be true or false,
525 ;;; deleting the IF node in favor of the appropriate branch when this
527 (defun ir1-optimize-if (node)
528 (declare (type cif node
))
529 (let ((test (if-test node
))
530 (block (node-block node
)))
532 (when (and (eq (block-start-node block
) node
)
533 (listp (lvar-uses test
)))
535 (when (immediately-used-p test use
)
536 (convert-if-if use node
)
537 (when (not (listp (lvar-uses test
))) (return)))))
539 (let* ((type (lvar-type test
))
541 (cond ((constant-lvar-p test
)
542 (if (lvar-value test
)
543 (if-alternative node
)
544 (if-consequent node
)))
545 ((not (types-equal-or-intersect type
(specifier-type 'null
)))
546 (if-alternative node
))
547 ((type= type
(specifier-type 'null
))
548 (if-consequent node
)))))
551 (when (rest (block-succ block
))
552 (unlink-blocks block victim
))
553 (setf (component-reanalyze (node-component node
)) t
)
554 (unlink-node node
))))
557 ;;; Create a new copy of an IF node that tests the value of the node
558 ;;; USE. The test must have >1 use, and must be immediately used by
559 ;;; USE. NODE must be the only node in its block (implying that
560 ;;; block-start = if-test).
562 ;;; This optimization has an effect semantically similar to the
563 ;;; source-to-source transformation:
564 ;;; (IF (IF A B C) D E) ==>
565 ;;; (IF A (IF B D E) (IF C D E))
567 ;;; We clobber the NODE-SOURCE-PATH of both the original and the new
568 ;;; node so that dead code deletion notes will definitely not consider
569 ;;; either node to be part of the original source. One node might
570 ;;; become unreachable, resulting in a spurious note.
571 (defun convert-if-if (use node
)
572 (declare (type node use
) (type cif node
))
573 (with-ir1-environment-from-node node
574 (let* ((block (node-block node
))
575 (test (if-test node
))
576 (cblock (if-consequent node
))
577 (ablock (if-alternative node
))
578 (use-block (node-block use
))
579 (new-ctran (make-ctran))
580 (new-lvar (make-lvar))
581 (new-node (make-if :test new-lvar
583 :alternative ablock
))
584 (new-block (ctran-starts-block new-ctran
)))
585 (link-node-to-previous-ctran new-node new-ctran
)
586 (setf (lvar-dest new-lvar
) new-node
)
587 (setf (block-last new-block
) new-node
)
589 (unlink-blocks use-block block
)
590 (%delete-lvar-use use
)
591 (add-lvar-use use new-lvar
)
592 (link-blocks use-block new-block
)
594 (link-blocks new-block cblock
)
595 (link-blocks new-block ablock
)
597 (push "<IF Duplication>" (node-source-path node
))
598 (push "<IF Duplication>" (node-source-path new-node
))
600 (reoptimize-lvar test
)
601 (reoptimize-lvar new-lvar
)
602 (setf (component-reanalyze *current-component
*) t
)))
605 ;;;; exit IR1 optimization
607 ;;; This function attempts to delete an exit node, returning true if
608 ;;; it deletes the block as a consequence:
609 ;;; -- If the exit is degenerate (has no ENTRY), then we don't do
610 ;;; anything, since there is nothing to be done.
611 ;;; -- If the exit node and its ENTRY have the same home lambda then
612 ;;; we know the exit is local, and can delete the exit. We change
613 ;;; uses of the Exit-Value to be uses of the original lvar,
614 ;;; then unlink the node. If the exit is to a TR context, then we
615 ;;; must do MERGE-TAIL-SETS on any local calls which delivered
616 ;;; their value to this exit.
617 ;;; -- If there is no value (as in a GO), then we skip the value
620 ;;; This function is also called by environment analysis, since it
621 ;;; wants all exits to be optimized even if normal optimization was
623 (defun maybe-delete-exit (node)
624 (declare (type exit node
))
625 (let ((value (exit-value node
))
626 (entry (exit-entry node
)))
628 (eq (node-home-lambda node
) (node-home-lambda entry
)))
629 (setf (entry-exits entry
) (delq node
(entry-exits entry
)))
631 (delete-filter node
(node-lvar node
) value
)
632 (unlink-node node
)))))
635 ;;;; combination IR1 optimization
637 ;;; Report as we try each transform?
639 (defvar *show-transforms-p
* nil
)
641 (defun check-important-result (node info
)
642 (when (and (null (node-lvar node
))
643 (ir1-attributep (fun-info-attributes info
) important-result
))
644 (let ((*compiler-error-context
* node
))
646 "The return value of ~A should not be discarded."
647 (lvar-fun-name (basic-combination-fun node
))))))
649 ;;; Do IR1 optimizations on a COMBINATION node.
650 (declaim (ftype (function (combination) (values)) ir1-optimize-combination
))
651 (defun ir1-optimize-combination (node)
652 (when (lvar-reoptimize (basic-combination-fun node
))
653 (propagate-fun-change node
)
654 (maybe-terminate-block node nil
))
655 (let ((args (basic-combination-args node
))
656 (kind (basic-combination-kind node
))
657 (info (basic-combination-fun-info node
)))
660 (let ((fun (combination-lambda node
)))
661 (if (eq (functional-kind fun
) :let
)
662 (propagate-let-args node fun
)
663 (propagate-local-call-args node fun
))))
667 (setf (lvar-reoptimize arg
) nil
))))
671 (setf (lvar-reoptimize arg
) nil
)))
673 (check-important-result node info
)
674 (let ((fun (fun-info-destroyed-constant-args info
)))
676 (let ((destroyed-constant-args (funcall fun args
)))
677 (when destroyed-constant-args
678 (let ((*compiler-error-context
* node
))
679 (warn 'constant-modified
680 :fun-name
(lvar-fun-name
681 (basic-combination-fun node
)))
682 (setf (basic-combination-kind node
) :error
)
683 (return-from ir1-optimize-combination
))))))
684 (let ((fun (fun-info-derive-type info
)))
686 (let ((res (funcall fun node
)))
688 (derive-node-type node
(coerce-to-values res
))
689 (maybe-terminate-block node nil
)))))))
694 (setf (lvar-reoptimize arg
) nil
)))
695 (check-important-result node info
)
696 (let ((fun (fun-info-destroyed-constant-args info
)))
698 ;; If somebody is really sure that they want to modify
699 ;; constants, let them.
700 (policy node
(> safety
0)))
701 (let ((destroyed-constant-args (funcall fun args
)))
702 (when destroyed-constant-args
703 (let ((*compiler-error-context
* node
))
704 (warn 'constant-modified
705 :fun-name
(lvar-fun-name
706 (basic-combination-fun node
)))
707 (setf (basic-combination-kind node
) :error
)
708 (return-from ir1-optimize-combination
))))))
710 (let ((attr (fun-info-attributes info
)))
711 (when (and (ir1-attributep attr foldable
)
712 ;; KLUDGE: The next test could be made more sensitive,
713 ;; only suppressing constant-folding of functions with
714 ;; CALL attributes when they're actually passed
715 ;; function arguments. -- WHN 19990918
716 (not (ir1-attributep attr call
))
717 (every #'constant-lvar-p args
)
719 (constant-fold-call node
)
720 (return-from ir1-optimize-combination
)))
722 (let ((fun (fun-info-derive-type info
)))
724 (let ((res (funcall fun node
)))
726 (derive-node-type node
(coerce-to-values res
))
727 (maybe-terminate-block node nil
)))))
729 (let ((fun (fun-info-optimizer info
)))
730 (unless (and fun
(funcall fun node
))
731 ;; First give the VM a peek at the call
732 (multiple-value-bind (style transform
)
733 (combination-implementation-style node
)
736 ;; The VM knows how to handle this.
739 ;; The VM mostly knows how to handle this. We need
740 ;; to massage the call slightly, though.
741 (transform-call node transform
(combination-fun-source-name node
)))
743 ;; Let transforms have a crack at it.
744 (dolist (x (fun-info-transforms info
))
746 (when *show-transforms-p
*
747 (let* ((lvar (basic-combination-fun node
))
748 (fname (lvar-fun-name lvar t
)))
749 (/show
"trying transform" x
(transform-function x
) "for" fname
)))
750 (unless (ir1-transform node x
)
752 (when *show-transforms-p
*
753 (/show
"quitting because IR1-TRANSFORM result was NIL"))
758 ;;; If NODE doesn't return (i.e. return type is NIL), then terminate
759 ;;; the block there, and link it to the component tail.
761 ;;; Except when called during IR1 convertion, we delete the
762 ;;; continuation if it has no other uses. (If it does have other uses,
765 ;;; Termination on the basis of a continuation type is
767 ;;; -- The continuation is deleted (hence the assertion is spurious), or
768 ;;; -- We are in IR1 conversion (where THE assertions are subject to
769 ;;; weakening.) FIXME: Now THE assertions are not weakened, but new
770 ;;; uses can(?) be added later. -- APD, 2003-07-17
772 ;;; Why do we need to consider LVAR type? -- APD, 2003-07-30
773 (defun maybe-terminate-block (node ir1-converting-not-optimizing-p
)
774 (declare (type (or basic-combination cast ref
) node
))
775 (let* ((block (node-block node
))
776 (lvar (node-lvar node
))
777 (ctran (node-next node
))
778 (tail (component-tail (block-component block
)))
779 (succ (first (block-succ block
))))
780 (declare (ignore lvar
))
781 (unless (or (and (eq node
(block-last block
)) (eq succ tail
))
782 (block-delete-p block
))
783 (when (eq (node-derived-type node
) *empty-type
*)
784 (cond (ir1-converting-not-optimizing-p
787 (aver (eq (block-last block
) node
)))
789 (setf (block-last block
) node
)
790 (setf (ctran-use ctran
) nil
)
791 (setf (ctran-kind ctran
) :unused
)
792 (setf (ctran-block ctran
) nil
)
793 (setf (node-next node
) nil
)
794 (link-blocks block
(ctran-starts-block ctran
)))))
796 (node-ends-block node
)))
798 (let ((succ (first (block-succ block
))))
799 (unlink-blocks block succ
)
800 (setf (component-reanalyze (block-component block
)) t
)
801 (aver (not (block-succ block
)))
802 (link-blocks block tail
)
803 (cond (ir1-converting-not-optimizing-p
804 (%delete-lvar-use node
))
805 (t (delete-lvar-use node
)
806 (when (null (block-pred succ
))
807 (mark-for-deletion succ
)))))
810 ;;; This is called both by IR1 conversion and IR1 optimization when
811 ;;; they have verified the type signature for the call, and are
812 ;;; wondering if something should be done to special-case the call. If
813 ;;; CALL is a call to a global function, then see whether it defined
815 ;;; -- If a DEFINED-FUN should be inline expanded, then convert
816 ;;; the expansion and change the call to call it. Expansion is
817 ;;; enabled if :INLINE or if SPACE=0. If the FUNCTIONAL slot is
818 ;;; true, we never expand, since this function has already been
819 ;;; converted. Local call analysis will duplicate the definition
820 ;;; if necessary. We claim that the parent form is LABELS for
821 ;;; context declarations, since we don't want it to be considered
822 ;;; a real global function.
823 ;;; -- If it is a known function, mark it as such by setting the KIND.
825 ;;; We return the leaf referenced (NIL if not a leaf) and the
826 ;;; FUN-INFO assigned.
827 (defun recognize-known-call (call ir1-converting-not-optimizing-p
)
828 (declare (type combination call
))
829 (let* ((ref (lvar-uses (basic-combination-fun call
)))
830 (leaf (when (ref-p ref
) (ref-leaf ref
)))
831 (inlinep (if (defined-fun-p leaf
)
832 (defined-fun-inlinep leaf
)
835 ((eq inlinep
:notinline
)
836 (let ((info (info :function
:info
(leaf-source-name leaf
))))
838 (setf (basic-combination-fun-info call
) info
))
840 ((not (and (global-var-p leaf
)
841 (eq (global-var-kind leaf
) :global-function
)))
846 ((nil :maybe-inline
) (policy call
(zerop space
))))
848 (defined-fun-inline-expansion leaf
)
849 (let ((fun (defined-fun-functional leaf
)))
851 (and (eq inlinep
:inline
) (functional-kind fun
))))
852 (inline-expansion-ok call
))
853 (flet (;; FIXME: Is this what the old CMU CL internal documentation
854 ;; called semi-inlining? A more descriptive name would
855 ;; be nice. -- WHN 2002-01-07
857 (let* ((name (leaf-source-name leaf
))
858 (res (ir1-convert-inline-expansion
860 (defined-fun-inline-expansion leaf
)
863 (info :function
:info name
))))
864 ;; allow backward references to this function from
865 ;; following top level forms
866 (setf (defined-fun-functional leaf
) res
)
867 (change-ref-leaf ref res
))))
868 (if ir1-converting-not-optimizing-p
870 (with-ir1-environment-from-node call
872 (locall-analyze-component *current-component
*))))
874 (values (ref-leaf (lvar-uses (basic-combination-fun call
)))
877 (let ((info (info :function
:info
(leaf-source-name leaf
))))
881 (setf (basic-combination-kind call
) :known
)
882 (setf (basic-combination-fun-info call
) info
)))
883 (values leaf nil
)))))))
885 ;;; Check whether CALL satisfies TYPE. If so, apply the type to the
886 ;;; call, and do MAYBE-TERMINATE-BLOCK and return the values of
887 ;;; RECOGNIZE-KNOWN-CALL. If an error, set the combination kind and
888 ;;; return NIL, NIL. If the type is just FUNCTION, then skip the
889 ;;; syntax check, arg/result type processing, but still call
890 ;;; RECOGNIZE-KNOWN-CALL, since the call might be to a known lambda,
891 ;;; and that checking is done by local call analysis.
892 (defun validate-call-type (call type ir1-converting-not-optimizing-p
)
893 (declare (type combination call
) (type ctype type
))
894 (cond ((not (fun-type-p type
))
895 (aver (multiple-value-bind (val win
)
896 (csubtypep type
(specifier-type 'function
))
898 (recognize-known-call call ir1-converting-not-optimizing-p
))
899 ((valid-fun-use call type
900 :argument-test
#'always-subtypep
902 ;; KLUDGE: Common Lisp is such a dynamic
903 ;; language that all we can do here in
904 ;; general is issue a STYLE-WARNING. It
905 ;; would be nice to issue a full WARNING
906 ;; in the special case of of type
907 ;; mismatches within a compilation unit
908 ;; (as in section 3.2.2.3 of the spec)
909 ;; but at least as of sbcl-0.6.11, we
910 ;; don't keep track of whether the
911 ;; mismatched data came from the same
912 ;; compilation unit, so we can't do that.
915 ;; FIXME: Actually, I think we could
916 ;; issue a full WARNING if the call
917 ;; violates a DECLAIM FTYPE.
918 :lossage-fun
#'compiler-style-warn
919 :unwinnage-fun
#'compiler-notify
)
920 (assert-call-type call type
)
921 (maybe-terminate-block call ir1-converting-not-optimizing-p
)
922 (recognize-known-call call ir1-converting-not-optimizing-p
))
924 (setf (combination-kind call
) :error
)
927 ;;; This is called by IR1-OPTIMIZE when the function for a call has
928 ;;; changed. If the call is local, we try to LET-convert it, and
929 ;;; derive the result type. If it is a :FULL call, we validate it
930 ;;; against the type, which recognizes known calls, does inline
931 ;;; expansion, etc. If a call to a predicate in a non-conditional
932 ;;; position or to a function with a source transform, then we
933 ;;; reconvert the form to give IR1 another chance.
934 (defun propagate-fun-change (call)
935 (declare (type combination call
))
936 (let ((*compiler-error-context
* call
)
937 (fun-lvar (basic-combination-fun call
)))
938 (setf (lvar-reoptimize fun-lvar
) nil
)
939 (case (combination-kind call
)
941 (let ((fun (combination-lambda call
)))
942 (maybe-let-convert fun
)
943 (unless (member (functional-kind fun
) '(:let
:assignment
:deleted
))
944 (derive-node-type call
(tail-set-type (lambda-tail-set fun
))))))
946 (multiple-value-bind (leaf info
)
947 (validate-call-type call
(lvar-type fun-lvar
) nil
)
948 (cond ((functional-p leaf
)
949 (convert-call-if-possible
950 (lvar-uses (basic-combination-fun call
))
953 ((and (global-var-p leaf
)
954 (eq (global-var-kind leaf
) :global-function
)
955 (leaf-has-source-name-p leaf
)
956 (or (info :function
:source-transform
(leaf-source-name leaf
))
958 (ir1-attributep (fun-info-attributes info
)
960 (let ((lvar (node-lvar call
)))
961 (and lvar
(not (if-p (lvar-dest lvar
))))))))
962 (let ((name (leaf-source-name leaf
))
963 (dummies (make-gensym-list
964 (length (combination-args call
)))))
967 (,@(if (symbolp name
)
971 (leaf-source-name leaf
)))))))))
974 ;;;; known function optimization
976 ;;; Add a failed optimization note to FAILED-OPTIMZATIONS for NODE,
977 ;;; FUN and ARGS. If there is already a note for NODE and TRANSFORM,
978 ;;; replace it, otherwise add a new one.
979 (defun record-optimization-failure (node transform args
)
980 (declare (type combination node
) (type transform transform
)
981 (type (or fun-type list
) args
))
982 (let* ((table (component-failed-optimizations *component-being-compiled
*))
983 (found (assoc transform
(gethash node table
))))
985 (setf (cdr found
) args
)
986 (push (cons transform args
) (gethash node table
))))
989 ;;; Attempt to transform NODE using TRANSFORM-FUNCTION, subject to the
990 ;;; call type constraint TRANSFORM-TYPE. If we are inhibited from
991 ;;; doing the transform for some reason and FLAME is true, then we
992 ;;; make a note of the message in FAILED-OPTIMIZATIONS for IR1
993 ;;; finalize to pick up. We return true if the transform failed, and
994 ;;; thus further transformation should be attempted. We return false
995 ;;; if either the transform succeeded or was aborted.
996 (defun ir1-transform (node transform
)
997 (declare (type combination node
) (type transform transform
))
998 (let* ((type (transform-type transform
))
999 (fun (transform-function transform
))
1000 (constrained (fun-type-p type
))
1001 (table (component-failed-optimizations *component-being-compiled
*))
1002 (flame (if (transform-important transform
)
1003 (policy node
(>= speed inhibit-warnings
))
1004 (policy node
(> speed inhibit-warnings
))))
1005 (*compiler-error-context
* node
))
1006 (cond ((or (not constrained
)
1007 (valid-fun-use node type
))
1008 (multiple-value-bind (severity args
)
1009 (catch 'give-up-ir1-transform
1010 (transform-call node
1012 (combination-fun-source-name node
))
1016 (remhash node table
)
1019 (setf (combination-kind node
) :error
)
1021 (apply #'warn args
))
1022 (remhash node table
)
1027 (record-optimization-failure node transform args
))
1028 (setf (gethash node table
)
1029 (remove transform
(gethash node table
) :key
#'car
)))
1032 (remhash node table
)
1037 :argument-test
#'types-equal-or-intersect
1038 :result-test
#'values-types-equal-or-intersect
))
1039 (record-optimization-failure node transform type
)
1044 ;;; When we don't like an IR1 transform, we throw the severity/reason
1047 ;;; GIVE-UP-IR1-TRANSFORM is used to throw out of an IR1 transform,
1048 ;;; aborting this attempt to transform the call, but admitting the
1049 ;;; possibility that this or some other transform will later succeed.
1050 ;;; If arguments are supplied, they are format arguments for an
1051 ;;; efficiency note.
1053 ;;; ABORT-IR1-TRANSFORM is used to throw out of an IR1 transform and
1054 ;;; force a normal call to the function at run time. No further
1055 ;;; optimizations will be attempted.
1057 ;;; DELAY-IR1-TRANSFORM is used to throw out of an IR1 transform, and
1058 ;;; delay the transform on the node until later. REASONS specifies
1059 ;;; when the transform will be later retried. The :OPTIMIZE reason
1060 ;;; causes the transform to be delayed until after the current IR1
1061 ;;; optimization pass. The :CONSTRAINT reason causes the transform to
1062 ;;; be delayed until after constraint propagation.
1064 ;;; FIXME: Now (0.6.11.44) that there are 4 variants of this (GIVE-UP,
1065 ;;; ABORT, DELAY/:OPTIMIZE, DELAY/:CONSTRAINT) and we're starting to
1066 ;;; do CASE operations on the various REASON values, it might be a
1067 ;;; good idea to go OO, representing the reasons by objects, using
1068 ;;; CLOS methods on the objects instead of CASE, and (possibly) using
1069 ;;; SIGNAL instead of THROW.
1070 (declaim (ftype (function (&rest t
) nil
) give-up-ir1-transform
))
1071 (defun give-up-ir1-transform (&rest args
)
1072 (throw 'give-up-ir1-transform
(values :failure args
)))
1073 (defun abort-ir1-transform (&rest args
)
1074 (throw 'give-up-ir1-transform
(values :aborted args
)))
1075 (defun delay-ir1-transform (node &rest reasons
)
1076 (let ((assoc (assoc node
*delayed-ir1-transforms
*)))
1078 (setf *delayed-ir1-transforms
*
1079 (acons node reasons
*delayed-ir1-transforms
*))
1080 (throw 'give-up-ir1-transform
:delayed
))
1082 (dolist (reason reasons
)
1083 (pushnew reason
(cdr assoc
)))
1084 (throw 'give-up-ir1-transform
:delayed
)))))
1086 ;;; Clear any delayed transform with no reasons - these should have
1087 ;;; been tried in the last pass. Then remove the reason from the
1088 ;;; delayed transform reasons, and if any become empty then set
1089 ;;; reoptimize flags for the node. Return true if any transforms are
1091 (defun retry-delayed-ir1-transforms (reason)
1092 (setf *delayed-ir1-transforms
*
1093 (remove-if-not #'cdr
*delayed-ir1-transforms
*))
1094 (let ((reoptimize nil
))
1095 (dolist (assoc *delayed-ir1-transforms
*)
1096 (let ((reasons (remove reason
(cdr assoc
))))
1097 (setf (cdr assoc
) reasons
)
1099 (let ((node (car assoc
)))
1100 (unless (node-deleted node
)
1102 (setf (node-reoptimize node
) t
)
1103 (let ((block (node-block node
)))
1104 (setf (block-reoptimize block
) t
)
1105 (reoptimize-component (block-component block
) :maybe
)))))))
1108 ;;; Take the lambda-expression RES, IR1 convert it in the proper
1109 ;;; environment, and then install it as the function for the call
1110 ;;; NODE. We do local call analysis so that the new function is
1111 ;;; integrated into the control flow.
1113 ;;; We require the original function source name in order to generate
1114 ;;; a meaningful debug name for the lambda we set up. (It'd be
1115 ;;; possible to do this starting from debug names as well as source
1116 ;;; names, but as of sbcl-0.7.1.5, there was no need for this
1117 ;;; generality, since source names are always known to our callers.)
1118 (defun transform-call (call res source-name
)
1119 (declare (type combination call
) (list res
))
1120 (aver (and (legal-fun-name-p source-name
)
1121 (not (eql source-name
'.anonymous.
))))
1122 (node-ends-block call
)
1123 ;; The internal variables of a transform are not going to be
1124 ;; interesting to the debugger, so there's no sense in
1125 ;; suppressing the substitution of variables with only one use
1126 ;; (the extra variables can slow down constraint propagation).
1128 ;; This needs to be done before the WITH-IR1-ENVIRONMENT-FROM-NODE,
1129 ;; so that it will bind *LEXENV* to the right environment.
1130 (setf (combination-lexenv call
)
1131 (make-lexenv :default
(combination-lexenv call
)
1132 :policy
(process-optimize-decl
1134 (preserve-single-use-debug-variables 0))
1136 (combination-lexenv call
)))))
1137 (with-ir1-environment-from-node call
1138 (with-component-last-block (*current-component
*
1139 (block-next (node-block call
)))
1141 (let ((new-fun (ir1-convert-inline-lambda
1143 :debug-name
(debug-name 'lambda-inlined source-name
)
1145 (ref (lvar-use (combination-fun call
))))
1146 (change-ref-leaf ref new-fun
)
1147 (setf (combination-kind call
) :full
)
1148 (locall-analyze-component *current-component
*))))
1151 ;;; Replace a call to a foldable function of constant arguments with
1152 ;;; the result of evaluating the form. If there is an error during the
1153 ;;; evaluation, we give a warning and leave the call alone, making the
1154 ;;; call a :ERROR call.
1156 ;;; If there is more than one value, then we transform the call into a
1158 (defun constant-fold-call (call)
1159 (let ((args (mapcar #'lvar-value
(combination-args call
)))
1160 (fun-name (combination-fun-source-name call
)))
1161 (multiple-value-bind (values win
)
1162 (careful-call fun-name
1165 ;; Note: CMU CL had COMPILER-WARN here, and that
1166 ;; seems more natural, but it's probably not.
1168 ;; It's especially not while bug 173 exists:
1171 ;; (UNLESS (OR UNSAFE? (<= END SIZE)))
1173 ;; can cause constant-folding TYPE-ERRORs (in
1174 ;; #'<=) when END can be proved to be NIL, even
1175 ;; though the code is perfectly legal and safe
1176 ;; because a NIL value of END means that the
1177 ;; #'<= will never be executed.
1179 ;; Moreover, even without bug 173,
1180 ;; quite-possibly-valid code like
1181 ;; (COND ((NONINLINED-PREDICATE END)
1182 ;; (UNLESS (<= END SIZE))
1184 ;; (where NONINLINED-PREDICATE is something the
1185 ;; compiler can't do at compile time, but which
1186 ;; turns out to make the #'<= expression
1187 ;; unreachable when END=NIL) could cause errors
1188 ;; when the compiler tries to constant-fold (<=
1191 ;; So, with or without bug 173, it'd be
1192 ;; unnecessarily evil to do a full
1193 ;; COMPILER-WARNING (and thus return FAILURE-P=T
1194 ;; from COMPILE-FILE) for legal code, so we we
1195 ;; use a wimpier COMPILE-STYLE-WARNING instead.
1196 #-sb-xc-host
#'compiler-style-warn
1197 ;; On the other hand, for code we control, we
1198 ;; should be able to work around any bug
1199 ;; 173-related problems, and in particular we
1200 ;; want to be alerted to calls to our own
1201 ;; functions which aren't being folded away; a
1202 ;; COMPILER-WARNING is butch enough to stop the
1203 ;; SBCL build itself in its tracks.
1204 #+sb-xc-host
#'compiler-warn
1207 (setf (combination-kind call
) :error
))
1208 ((and (proper-list-of-length-p values
1))
1209 (with-ir1-environment-from-node call
1210 (let* ((lvar (node-lvar call
))
1211 (prev (node-prev call
))
1212 (intermediate-ctran (make-ctran)))
1213 (%delete-lvar-use call
)
1214 (setf (ctran-next prev
) nil
)
1215 (setf (node-prev call
) nil
)
1216 (reference-constant prev intermediate-ctran lvar
1218 (link-node-to-previous-ctran call intermediate-ctran
)
1219 (reoptimize-lvar lvar
)
1220 (flush-combination call
))))
1221 (t (let ((dummies (make-gensym-list (length args
))))
1225 (declare (ignore ,@dummies
))
1226 (values ,@(mapcar (lambda (x) `',x
) values
)))
1230 ;;;; local call optimization
1232 ;;; Propagate TYPE to LEAF and its REFS, marking things changed. If
1233 ;;; the leaf type is a function type, then just leave it alone, since
1234 ;;; TYPE is never going to be more specific than that (and
1235 ;;; TYPE-INTERSECTION would choke.)
1236 (defun propagate-to-refs (leaf type
)
1237 (declare (type leaf leaf
) (type ctype type
))
1238 (let ((var-type (leaf-type leaf
)))
1239 (unless (fun-type-p var-type
)
1240 (let ((int (type-approx-intersection2 var-type type
)))
1241 (when (type/= int var-type
)
1242 (setf (leaf-type leaf
) int
)
1243 (dolist (ref (leaf-refs leaf
))
1244 (derive-node-type ref
(make-single-value-type int
))
1245 ;; KLUDGE: LET var substitution
1246 (let* ((lvar (node-lvar ref
)))
1247 (when (and lvar
(combination-p (lvar-dest lvar
)))
1248 (reoptimize-lvar lvar
))))))
1251 ;;; Iteration variable: exactly one SETQ of the form:
1253 ;;; (let ((var initial))
1255 ;;; (setq var (+ var step))
1257 (defun maybe-infer-iteration-var-type (var initial-type
)
1258 (binding* ((sets (lambda-var-sets var
) :exit-if-null
)
1260 (() (null (rest sets
)) :exit-if-null
)
1261 (set-use (principal-lvar-use (set-value set
)))
1262 (() (and (combination-p set-use
)
1263 (eq (combination-kind set-use
) :known
)
1264 (fun-info-p (combination-fun-info set-use
))
1265 (not (node-to-be-deleted-p set-use
))
1266 (or (eq (combination-fun-source-name set-use
) '+)
1267 (eq (combination-fun-source-name set-use
) '-
)))
1269 (minusp (eq (combination-fun-source-name set-use
) '-
))
1270 (+-args
(basic-combination-args set-use
))
1271 (() (and (proper-list-of-length-p +-args
2 2)
1272 (let ((first (principal-lvar-use
1275 (eq (ref-leaf first
) var
))))
1277 (step-type (lvar-type (second +-args
)))
1278 (set-type (lvar-type (set-value set
))))
1279 (when (and (numeric-type-p initial-type
)
1280 (numeric-type-p step-type
)
1281 (or (numeric-type-equal initial-type step-type
)
1282 ;; Detect cases like (LOOP FOR 1.0 to 5.0 ...), where
1283 ;; the initial and the step are of different types,
1284 ;; and the step is less contagious.
1285 (numeric-type-equal initial-type
1286 (numeric-contagion initial-type
1288 (labels ((leftmost (x y cmp cmp
=)
1289 (cond ((eq x nil
) nil
)
1292 (let ((x1 (first x
)))
1294 (let ((y1 (first y
)))
1295 (if (funcall cmp x1 y1
) x y
)))
1297 (if (funcall cmp x1 y
) x y
)))))
1299 (let ((y1 (first y
)))
1300 (if (funcall cmp
= x y1
) x y
)))
1301 (t (if (funcall cmp x y
) x y
))))
1302 (max* (x y
) (leftmost x y
#'> #'>=))
1303 (min* (x y
) (leftmost x y
#'< #'<=)))
1304 (multiple-value-bind (low high
)
1305 (let ((step-type-non-negative (csubtypep step-type
(specifier-type
1307 (step-type-non-positive (csubtypep step-type
(specifier-type
1309 (cond ((or (and step-type-non-negative
(not minusp
))
1310 (and step-type-non-positive minusp
))
1311 (values (numeric-type-low initial-type
)
1312 (when (and (numeric-type-p set-type
)
1313 (numeric-type-equal set-type initial-type
))
1314 (max* (numeric-type-high initial-type
)
1315 (numeric-type-high set-type
)))))
1316 ((or (and step-type-non-positive
(not minusp
))
1317 (and step-type-non-negative minusp
))
1318 (values (when (and (numeric-type-p set-type
)
1319 (numeric-type-equal set-type initial-type
))
1320 (min* (numeric-type-low initial-type
)
1321 (numeric-type-low set-type
)))
1322 (numeric-type-high initial-type
)))
1325 (modified-numeric-type initial-type
1328 :enumerable nil
))))))
1329 (deftransform + ((x y
) * * :result result
)
1330 "check for iteration variable reoptimization"
1331 (let ((dest (principal-lvar-end result
))
1332 (use (principal-lvar-use x
)))
1333 (when (and (ref-p use
)
1337 (reoptimize-lvar (set-value dest
))))
1338 (give-up-ir1-transform))
1340 ;;; Figure out the type of a LET variable that has sets. We compute
1341 ;;; the union of the INITIAL-TYPE and the types of all the set
1342 ;;; values and to a PROPAGATE-TO-REFS with this type.
1343 (defun propagate-from-sets (var initial-type
)
1344 (collect ((res initial-type type-union
))
1345 (dolist (set (basic-var-sets var
))
1346 (let ((type (lvar-type (set-value set
))))
1348 (when (node-reoptimize set
)
1349 (derive-node-type set
(make-single-value-type type
))
1350 (setf (node-reoptimize set
) nil
))))
1352 (awhen (maybe-infer-iteration-var-type var initial-type
)
1354 (propagate-to-refs var res
)))
1357 ;;; If a LET variable, find the initial value's type and do
1358 ;;; PROPAGATE-FROM-SETS. We also derive the VALUE's type as the node's
1360 (defun ir1-optimize-set (node)
1361 (declare (type cset node
))
1362 (let ((var (set-var node
)))
1363 (when (and (lambda-var-p var
) (leaf-refs var
))
1364 (let ((home (lambda-var-home var
)))
1365 (when (eq (functional-kind home
) :let
)
1366 (let* ((initial-value (let-var-initial-value var
))
1367 (initial-type (lvar-type initial-value
)))
1368 (setf (lvar-reoptimize initial-value
) nil
)
1369 (propagate-from-sets var initial-type
))))))
1371 (derive-node-type node
(make-single-value-type
1372 (lvar-type (set-value node
))))
1375 ;;; Return true if the value of REF will always be the same (and is
1376 ;;; thus legal to substitute.)
1377 (defun constant-reference-p (ref)
1378 (declare (type ref ref
))
1379 (let ((leaf (ref-leaf ref
)))
1381 ((or constant functional
) t
)
1383 (null (lambda-var-sets leaf
)))
1385 (not (eq (defined-fun-inlinep leaf
) :notinline
)))
1387 (case (global-var-kind leaf
)
1389 (let ((name (leaf-source-name leaf
)))
1391 (eq (symbol-package (fun-name-block-name name
))
1393 (info :function
:info name
)))))))))
1395 ;;; If we have a non-set LET var with a single use, then (if possible)
1396 ;;; replace the variable reference's LVAR with the arg lvar.
1398 ;;; We change the REF to be a reference to NIL with unused value, and
1399 ;;; let it be flushed as dead code. A side effect of this substitution
1400 ;;; is to delete the variable.
1401 (defun substitute-single-use-lvar (arg var
)
1402 (declare (type lvar arg
) (type lambda-var var
))
1403 (binding* ((ref (first (leaf-refs var
)))
1404 (lvar (node-lvar ref
) :exit-if-null
)
1405 (dest (lvar-dest lvar
)))
1407 ;; Think about (LET ((A ...)) (IF ... A ...)): two
1408 ;; LVAR-USEs should not be met on one path. Another problem
1409 ;; is with dynamic-extent.
1410 (eq (lvar-uses lvar
) ref
)
1411 (not (block-delete-p (node-block ref
)))
1413 ;; we should not change lifetime of unknown values lvars
1415 (and (type-single-value-p (lvar-derived-type arg
))
1416 (multiple-value-bind (pdest pprev
)
1417 (principal-lvar-end lvar
)
1418 (declare (ignore pdest
))
1419 (lvar-single-value-p pprev
))))
1421 (or (eq (basic-combination-fun dest
) lvar
)
1422 (and (eq (basic-combination-kind dest
) :local
)
1423 (type-single-value-p (lvar-derived-type arg
)))))
1425 ;; While CRETURN and EXIT nodes may be known-values,
1426 ;; they have their own complications, such as
1427 ;; substitution into CRETURN may create new tail calls.
1430 (aver (lvar-single-value-p lvar
))
1432 (eq (node-home-lambda ref
)
1433 (lambda-home (lambda-var-home var
))))
1434 (let ((ref-type (single-value-type (node-derived-type ref
))))
1435 (cond ((csubtypep (single-value-type (lvar-type arg
)) ref-type
)
1436 (substitute-lvar-uses lvar arg
1437 ;; Really it is (EQ (LVAR-USES LVAR) REF):
1439 (delete-lvar-use ref
))
1441 (let* ((value (make-lvar))
1442 (cast (insert-cast-before ref value ref-type
1443 ;; KLUDGE: it should be (TYPE-CHECK 0)
1445 (setf (cast-type-to-check cast
) *wild-type
*)
1446 (substitute-lvar-uses value arg
1449 (%delete-lvar-use ref
)
1450 (add-lvar-use cast lvar
)))))
1451 (setf (node-derived-type ref
) *wild-type
*)
1452 (change-ref-leaf ref
(find-constant nil
))
1455 (reoptimize-lvar lvar
)
1458 ;;; Delete a LET, removing the call and bind nodes, and warning about
1459 ;;; any unreferenced variables. Note that FLUSH-DEAD-CODE will come
1460 ;;; along right away and delete the REF and then the lambda, since we
1461 ;;; flush the FUN lvar.
1462 (defun delete-let (clambda)
1463 (declare (type clambda clambda
))
1464 (aver (functional-letlike-p clambda
))
1465 (note-unreferenced-vars clambda
)
1466 (let ((call (let-combination clambda
)))
1467 (flush-dest (basic-combination-fun call
))
1469 (unlink-node (lambda-bind clambda
))
1470 (setf (lambda-bind clambda
) nil
))
1471 (setf (functional-kind clambda
) :zombie
)
1472 (let ((home (lambda-home clambda
)))
1473 (setf (lambda-lets home
) (delete clambda
(lambda-lets home
))))
1476 ;;; This function is called when one of the arguments to a LET
1477 ;;; changes. We look at each changed argument. If the corresponding
1478 ;;; variable is set, then we call PROPAGATE-FROM-SETS. Otherwise, we
1479 ;;; consider substituting for the variable, and also propagate
1480 ;;; derived-type information for the arg to all the VAR's refs.
1482 ;;; Substitution is inhibited when the arg leaf's derived type isn't a
1483 ;;; subtype of the argument's leaf type. This prevents type checking
1484 ;;; from being defeated, and also ensures that the best representation
1485 ;;; for the variable can be used.
1487 ;;; Substitution of individual references is inhibited if the
1488 ;;; reference is in a different component from the home. This can only
1489 ;;; happen with closures over top level lambda vars. In such cases,
1490 ;;; the references may have already been compiled, and thus can't be
1491 ;;; retroactively modified.
1493 ;;; If all of the variables are deleted (have no references) when we
1494 ;;; are done, then we delete the LET.
1496 ;;; Note that we are responsible for clearing the LVAR-REOPTIMIZE
1498 (defun propagate-let-args (call fun
)
1499 (declare (type combination call
) (type clambda fun
))
1500 (loop for arg in
(combination-args call
)
1501 and var in
(lambda-vars fun
) do
1502 (when (and arg
(lvar-reoptimize arg
))
1503 (setf (lvar-reoptimize arg
) nil
)
1505 ((lambda-var-sets var
)
1506 (propagate-from-sets var
(lvar-type arg
)))
1507 ((let ((use (lvar-uses arg
)))
1509 (let ((leaf (ref-leaf use
)))
1510 (when (and (constant-reference-p use
)
1511 (csubtypep (leaf-type leaf
)
1512 ;; (NODE-DERIVED-TYPE USE) would
1513 ;; be better -- APD, 2003-05-15
1515 (propagate-to-refs var
(lvar-type arg
))
1516 (let ((use-component (node-component use
)))
1517 (prog1 (substitute-leaf-if
1519 (cond ((eq (node-component ref
) use-component
)
1522 (aver (lambda-toplevelish-p (lambda-home fun
)))
1526 ((and (null (rest (leaf-refs var
)))
1527 ;; Don't substitute single-ref variables on high-debug /
1528 ;; low speed, to improve the debugging experience.
1529 (policy call
(< preserve-single-use-debug-variables
3))
1530 (substitute-single-use-lvar arg var
)))
1532 (propagate-to-refs var
(lvar-type arg
))))))
1534 (when (every #'not
(combination-args call
))
1539 ;;; This function is called when one of the args to a non-LET local
1540 ;;; call changes. For each changed argument corresponding to an unset
1541 ;;; variable, we compute the union of the types across all calls and
1542 ;;; propagate this type information to the var's refs.
1544 ;;; If the function has an XEP, then we don't do anything, since we
1545 ;;; won't discover anything.
1547 ;;; We can clear the LVAR-REOPTIMIZE flags for arguments in all calls
1548 ;;; corresponding to changed arguments in CALL, since the only use in
1549 ;;; IR1 optimization of the REOPTIMIZE flag for local call args is
1551 (defun propagate-local-call-args (call fun
)
1552 (declare (type combination call
) (type clambda fun
))
1553 (unless (or (functional-entry-fun fun
)
1554 (lambda-optional-dispatch fun
))
1555 (let* ((vars (lambda-vars fun
))
1556 (union (mapcar (lambda (arg var
)
1558 (lvar-reoptimize arg
)
1559 (null (basic-var-sets var
)))
1561 (basic-combination-args call
)
1563 (this-ref (lvar-use (basic-combination-fun call
))))
1565 (dolist (arg (basic-combination-args call
))
1567 (setf (lvar-reoptimize arg
) nil
)))
1569 (dolist (ref (leaf-refs fun
))
1570 (let ((dest (node-dest ref
)))
1571 (unless (or (eq ref this-ref
) (not dest
))
1573 (mapcar (lambda (this-arg old
)
1575 (setf (lvar-reoptimize this-arg
) nil
)
1576 (type-union (lvar-type this-arg
) old
)))
1577 (basic-combination-args dest
)
1580 (loop for var in vars
1582 when type do
(propagate-to-refs var type
))))
1586 ;;;; multiple values optimization
1588 ;;; Do stuff to notice a change to a MV combination node. There are
1589 ;;; two main branches here:
1590 ;;; -- If the call is local, then it is already a MV let, or should
1591 ;;; become one. Note that although all :LOCAL MV calls must eventually
1592 ;;; be converted to :MV-LETs, there can be a window when the call
1593 ;;; is local, but has not been LET converted yet. This is because
1594 ;;; the entry-point lambdas may have stray references (in other
1595 ;;; entry points) that have not been deleted yet.
1596 ;;; -- The call is full. This case is somewhat similar to the non-MV
1597 ;;; combination optimization: we propagate return type information and
1598 ;;; notice non-returning calls. We also have an optimization
1599 ;;; which tries to convert MV-CALLs into MV-binds.
1600 (defun ir1-optimize-mv-combination (node)
1601 (ecase (basic-combination-kind node
)
1603 (let ((fun-lvar (basic-combination-fun node
)))
1604 (when (lvar-reoptimize fun-lvar
)
1605 (setf (lvar-reoptimize fun-lvar
) nil
)
1606 (maybe-let-convert (combination-lambda node
))))
1607 (setf (lvar-reoptimize (first (basic-combination-args node
))) nil
)
1608 (when (eq (functional-kind (combination-lambda node
)) :mv-let
)
1609 (unless (convert-mv-bind-to-let node
)
1610 (ir1-optimize-mv-bind node
))))
1612 (let* ((fun (basic-combination-fun node
))
1613 (fun-changed (lvar-reoptimize fun
))
1614 (args (basic-combination-args node
)))
1616 (setf (lvar-reoptimize fun
) nil
)
1617 (let ((type (lvar-type fun
)))
1618 (when (fun-type-p type
)
1619 (derive-node-type node
(fun-type-returns type
))))
1620 (maybe-terminate-block node nil
)
1621 (let ((use (lvar-uses fun
)))
1622 (when (and (ref-p use
) (functional-p (ref-leaf use
)))
1623 (convert-call-if-possible use node
)
1624 (when (eq (basic-combination-kind node
) :local
)
1625 (maybe-let-convert (ref-leaf use
))))))
1626 (unless (or (eq (basic-combination-kind node
) :local
)
1627 (eq (lvar-fun-name fun
) '%throw
))
1628 (ir1-optimize-mv-call node
))
1630 (setf (lvar-reoptimize arg
) nil
))))
1634 ;;; Propagate derived type info from the values lvar to the vars.
1635 (defun ir1-optimize-mv-bind (node)
1636 (declare (type mv-combination node
))
1637 (let* ((arg (first (basic-combination-args node
)))
1638 (vars (lambda-vars (combination-lambda node
)))
1639 (n-vars (length vars
))
1640 (types (values-type-in (lvar-derived-type arg
)
1642 (loop for var in vars
1644 do
(if (basic-var-sets var
)
1645 (propagate-from-sets var type
)
1646 (propagate-to-refs var type
)))
1647 (setf (lvar-reoptimize arg
) nil
))
1650 ;;; If possible, convert a general MV call to an MV-BIND. We can do
1652 ;;; -- The call has only one argument, and
1653 ;;; -- The function has a known fixed number of arguments, or
1654 ;;; -- The argument yields a known fixed number of values.
1656 ;;; What we do is change the function in the MV-CALL to be a lambda
1657 ;;; that "looks like an MV bind", which allows
1658 ;;; IR1-OPTIMIZE-MV-COMBINATION to notice that this call can be
1659 ;;; converted (the next time around.) This new lambda just calls the
1660 ;;; actual function with the MV-BIND variables as arguments. Note that
1661 ;;; this new MV bind is not let-converted immediately, as there are
1662 ;;; going to be stray references from the entry-point functions until
1663 ;;; they get deleted.
1665 ;;; In order to avoid loss of argument count checking, we only do the
1666 ;;; transformation according to a known number of expected argument if
1667 ;;; safety is unimportant. We can always convert if we know the number
1668 ;;; of actual values, since the normal call that we build will still
1669 ;;; do any appropriate argument count checking.
1671 ;;; We only attempt the transformation if the called function is a
1672 ;;; constant reference. This allows us to just splice the leaf into
1673 ;;; the new function, instead of trying to somehow bind the function
1674 ;;; expression. The leaf must be constant because we are evaluating it
1675 ;;; again in a different place. This also has the effect of squelching
1676 ;;; multiple warnings when there is an argument count error.
1677 (defun ir1-optimize-mv-call (node)
1678 (let ((fun (basic-combination-fun node
))
1679 (*compiler-error-context
* node
)
1680 (ref (lvar-uses (basic-combination-fun node
)))
1681 (args (basic-combination-args node
)))
1683 (unless (and (ref-p ref
) (constant-reference-p ref
)
1685 (return-from ir1-optimize-mv-call
))
1687 (multiple-value-bind (min max
)
1688 (fun-type-nargs (lvar-type fun
))
1690 (multiple-value-bind (types nvals
)
1691 (values-types (lvar-derived-type (first args
)))
1692 (declare (ignore types
))
1693 (if (eq nvals
:unknown
) nil nvals
))))
1696 (when (and min
(< total-nvals min
))
1698 "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
1701 (setf (basic-combination-kind node
) :error
)
1702 (return-from ir1-optimize-mv-call
))
1703 (when (and max
(> total-nvals max
))
1705 "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
1708 (setf (basic-combination-kind node
) :error
)
1709 (return-from ir1-optimize-mv-call
)))
1711 (let ((count (cond (total-nvals)
1712 ((and (policy node
(zerop verify-arg-count
))
1717 (with-ir1-environment-from-node node
1718 (let* ((dums (make-gensym-list count
))
1720 (leaf (ref-leaf ref
))
1721 (fun (ir1-convert-lambda
1722 `(lambda (&optional
,@dums
&rest
,ignore
)
1723 (declare (ignore ,ignore
))
1724 (%funcall
,leaf
,@dums
))
1725 :source-name
(leaf-%source-name leaf
)
1726 :debug-name
(leaf-%debug-name leaf
))))
1727 (change-ref-leaf ref fun
)
1728 (aver (eq (basic-combination-kind node
) :full
))
1729 (locall-analyze-component *current-component
*)
1730 (aver (eq (basic-combination-kind node
) :local
)))))))))
1734 ;;; (multiple-value-bind
1743 ;;; What we actually do is convert the VALUES combination into a
1744 ;;; normal LET combination calling the original :MV-LET lambda. If
1745 ;;; there are extra args to VALUES, discard the corresponding
1746 ;;; lvars. If there are insufficient args, insert references to NIL.
1747 (defun convert-mv-bind-to-let (call)
1748 (declare (type mv-combination call
))
1749 (let* ((arg (first (basic-combination-args call
)))
1750 (use (lvar-uses arg
)))
1751 (when (and (combination-p use
)
1752 (eq (lvar-fun-name (combination-fun use
))
1754 (let* ((fun (combination-lambda call
))
1755 (vars (lambda-vars fun
))
1756 (vals (combination-args use
))
1757 (nvars (length vars
))
1758 (nvals (length vals
)))
1759 (cond ((> nvals nvars
)
1760 (mapc #'flush-dest
(subseq vals nvars
))
1761 (setq vals
(subseq vals
0 nvars
)))
1763 (with-ir1-environment-from-node use
1764 (let ((node-prev (node-prev use
)))
1765 (setf (node-prev use
) nil
)
1766 (setf (ctran-next node-prev
) nil
)
1767 (collect ((res vals
))
1768 (loop for count below
(- nvars nvals
)
1769 for prev
= node-prev then ctran
1770 for ctran
= (make-ctran)
1771 and lvar
= (make-lvar use
)
1772 do
(reference-constant prev ctran lvar nil
)
1774 finally
(link-node-to-previous-ctran
1776 (setq vals
(res)))))))
1777 (setf (combination-args use
) vals
)
1778 (flush-dest (combination-fun use
))
1779 (let ((fun-lvar (basic-combination-fun call
)))
1780 (setf (lvar-dest fun-lvar
) use
)
1781 (setf (combination-fun use
) fun-lvar
)
1782 (flush-lvar-externally-checkable-type fun-lvar
))
1783 (setf (combination-kind use
) :local
)
1784 (setf (functional-kind fun
) :let
)
1785 (flush-dest (first (basic-combination-args call
)))
1788 (reoptimize-lvar (first vals
)))
1789 (propagate-to-args use fun
)
1790 (reoptimize-call use
))
1794 ;;; (values-list (list x y z))
1799 ;;; In implementation, this is somewhat similar to
1800 ;;; CONVERT-MV-BIND-TO-LET. We grab the args of LIST and make them
1801 ;;; args of the VALUES-LIST call, flushing the old argument lvar
1802 ;;; (allowing the LIST to be flushed.)
1804 ;;; FIXME: Thus we lose possible type assertions on (LIST ...).
1805 (defoptimizer (values-list optimizer
) ((list) node
)
1806 (let ((use (lvar-uses list
)))
1807 (when (and (combination-p use
)
1808 (eq (lvar-fun-name (combination-fun use
))
1811 ;; FIXME: VALUES might not satisfy an assertion on NODE-LVAR.
1812 (change-ref-leaf (lvar-uses (combination-fun node
))
1813 (find-free-fun 'values
"in a strange place"))
1814 (setf (combination-kind node
) :full
)
1815 (let ((args (combination-args use
)))
1817 (setf (lvar-dest arg
) node
)
1818 (flush-lvar-externally-checkable-type arg
))
1819 (setf (combination-args use
) nil
)
1821 (setf (combination-args node
) args
))
1824 ;;; If VALUES appears in a non-MV context, then effectively convert it
1825 ;;; to a PROG1. This allows the computation of the additional values
1826 ;;; to become dead code.
1827 (deftransform values
((&rest vals
) * * :node node
)
1828 (unless (lvar-single-value-p (node-lvar node
))
1829 (give-up-ir1-transform))
1830 (setf (node-derived-type node
)
1831 (make-short-values-type (list (single-value-type
1832 (node-derived-type node
)))))
1833 (principal-lvar-single-valuify (node-lvar node
))
1835 (let ((dummies (make-gensym-list (length (cdr vals
)))))
1836 `(lambda (val ,@dummies
)
1837 (declare (ignore ,@dummies
))
1843 (defun delete-cast (cast)
1844 (declare (type cast cast
))
1845 (let ((value (cast-value cast
))
1846 (lvar (node-lvar cast
)))
1847 (delete-filter cast lvar value
)
1849 (reoptimize-lvar lvar
)
1850 (when (lvar-single-value-p lvar
)
1851 (note-single-valuified-lvar lvar
)))
1854 (defun ir1-optimize-cast (cast &optional do-not-optimize
)
1855 (declare (type cast cast
))
1856 (let ((value (cast-value cast
))
1857 (atype (cast-asserted-type cast
)))
1858 (when (not do-not-optimize
)
1859 (let ((lvar (node-lvar cast
)))
1860 (when (values-subtypep (lvar-derived-type value
)
1861 (cast-asserted-type cast
))
1863 (return-from ir1-optimize-cast t
))
1865 (when (and (listp (lvar-uses value
))
1867 ;; Pathwise removing of CAST
1868 (let ((ctran (node-next cast
))
1869 (dest (lvar-dest lvar
))
1872 (do-uses (use value
)
1873 (when (and (values-subtypep (node-derived-type use
) atype
)
1874 (immediately-used-p value use
))
1876 (when ctran
(ensure-block-start ctran
))
1877 (setq next-block
(first (block-succ (node-block cast
))))
1878 (ensure-block-start (node-prev cast
))
1879 (reoptimize-lvar lvar
)
1880 (setf (lvar-%derived-type value
) nil
))
1881 (%delete-lvar-use use
)
1882 (add-lvar-use use lvar
)
1883 (unlink-blocks (node-block use
) (node-block cast
))
1884 (link-blocks (node-block use
) next-block
)
1885 (when (and (return-p dest
)
1886 (basic-combination-p use
)
1887 (eq (basic-combination-kind use
) :local
))
1889 (dolist (use (merges))
1890 (merge-tail-sets use
)))))))
1892 (let* ((value-type (lvar-derived-type value
))
1893 (int (values-type-intersection value-type atype
)))
1894 (derive-node-type cast int
)
1895 (when (eq int
*empty-type
*)
1896 (unless (eq value-type
*empty-type
*)
1898 ;; FIXME: Do it in one step.
1901 (if (cast-single-value-p cast
)
1903 `(multiple-value-call #'list
'dummy
)))
1906 ;; FIXME: Derived type.
1907 `(%compile-time-type-error
'dummy
1908 ',(type-specifier atype
)
1909 ',(type-specifier value-type
)))
1910 ;; KLUDGE: FILTER-LVAR does not work for non-returning
1911 ;; functions, so we declare the return type of
1912 ;; %COMPILE-TIME-TYPE-ERROR to be * and derive the real type
1914 (setq value
(cast-value cast
))
1915 (derive-node-type (lvar-uses value
) *empty-type
*)
1916 (maybe-terminate-block (lvar-uses value
) nil
)
1917 ;; FIXME: Is it necessary?
1918 (aver (null (block-pred (node-block cast
))))
1919 (delete-block-lazily (node-block cast
))
1920 (return-from ir1-optimize-cast
)))
1921 (when (eq (node-derived-type cast
) *empty-type
*)
1922 (maybe-terminate-block cast nil
))
1924 (when (and (cast-%type-check cast
)
1925 (values-subtypep value-type
1926 (cast-type-to-check cast
)))
1927 (setf (cast-%type-check cast
) nil
))))
1929 (unless do-not-optimize
1930 (setf (node-reoptimize cast
) nil
)))
1932 (deftransform make-symbol
((string) (simple-string))
1933 `(%make-symbol string
))