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 (or (let ((use (principal-lvar-use thing)))
27 (and (ref-p use) (constant-p (ref-leaf use))))
28 ;; check for EQL types (but not singleton numeric types)
29 (let ((type (lvar-type thing)))
30 (values (type-singleton-p type))))))
32 ;;; Return the constant value for an LVAR whose only use is a constant
34 (declaim (ftype (function (lvar) t) lvar-value))
35 (defun lvar-value (lvar)
36 (let ((use (principal-lvar-use lvar))
37 (type (lvar-type lvar))
40 (constant-p (setf leaf (ref-leaf use))))
42 (multiple-value-bind (constantp value) (type-singleton-p type)
44 (error "~S used on non-constant LVAR ~S" 'lvar-value lvar))
47 ;;;; interface for obtaining results of type inference
49 ;;; Our best guess for the type of this lvar's value. Note that this
50 ;;; may be VALUES or FUNCTION type, which cannot be passed as an
51 ;;; argument to the normal type operations. See LVAR-TYPE.
53 ;;; The result value is cached in the LVAR-%DERIVED-TYPE slot. If the
54 ;;; slot is true, just return that value, otherwise recompute and
55 ;;; stash the value there.
56 (eval-when (:compile-toplevel :execute)
57 (#+sb-xc-host cl:defmacro
58 #-sb-xc-host sb!xc:defmacro
59 lvar-type-using (lvar accessor)
60 `(let ((uses (lvar-uses ,lvar)))
61 (cond ((null uses) *empty-type*)
63 (do ((res (,accessor (first uses))
64 (values-type-union (,accessor (first current))
66 (current (rest uses) (rest current)))
67 ((or (null current) (eq res *wild-type*))
72 #!-sb-fluid (declaim (inline lvar-derived-type))
73 (defun lvar-derived-type (lvar)
74 (declare (type lvar lvar))
75 (or (lvar-%derived-type lvar)
76 (setf (lvar-%derived-type lvar)
77 (%lvar-derived-type lvar))))
78 (defun %lvar-derived-type (lvar)
79 (lvar-type-using lvar node-derived-type))
81 ;;; Return the derived type for LVAR's first value. This is guaranteed
82 ;;; not to be a VALUES or FUNCTION type.
83 (declaim (ftype (sfunction (lvar) ctype) lvar-type))
84 (defun lvar-type (lvar)
85 (single-value-type (lvar-derived-type lvar)))
87 ;;; LVAR-CONSERVATIVE-TYPE
89 ;;; Certain types refer to the contents of an object, which can
90 ;;; change without type derivation noticing: CONS types and ARRAY
91 ;;; types suffer from this:
93 ;;; (let ((x (the (cons fixnum fixnum) (cons a b))))
95 ;;; (+ (car x) (cdr x)))
97 ;;; Python doesn't realize that the SETF CAR can change the type of X -- so we
98 ;;; cannot use LVAR-TYPE which gets the derived results. Worse, still, instead
99 ;;; of (SETF CAR) we might have a call to a user-defined function FOO which
100 ;;; does the same -- so there is no way to use the derived information in
103 ;;; So, the conservative option is to use the derived type if the leaf has
104 ;;; only a single ref -- in which case there cannot be a prior call that
105 ;;; mutates it. Otherwise we use the declared type or punt to the most general
106 ;;; type we know to be correct for sure.
107 (defun lvar-conservative-type (lvar)
108 (let ((derived-type (lvar-type lvar))
109 (t-type *universal-type*))
110 ;; Recompute using NODE-CONSERVATIVE-TYPE instead of derived type if
111 ;; necessary -- picking off some easy cases up front.
112 (cond ((or (eq derived-type t-type)
113 ;; Can't use CSUBTYPEP!
114 (type= derived-type (specifier-type 'list))
115 (type= derived-type (specifier-type 'null)))
117 ((and (cons-type-p derived-type)
118 (eq t-type (cons-type-car-type derived-type))
119 (eq t-type (cons-type-cdr-type derived-type)))
121 ((and (array-type-p derived-type)
122 (or (not (array-type-complexp derived-type))
123 (let ((dimensions (array-type-dimensions derived-type)))
124 (or (eq '* dimensions)
125 (every (lambda (dim) (eq '* dim)) dimensions)))))
127 ((type-needs-conservation-p derived-type)
128 (single-value-type (lvar-type-using lvar node-conservative-type)))
132 (defun node-conservative-type (node)
133 (let* ((derived-values-type (node-derived-type node))
134 (derived-type (single-value-type derived-values-type)))
136 (let ((leaf (ref-leaf node)))
137 (if (and (basic-var-p leaf)
138 (cdr (leaf-refs leaf)))
140 (if (eq :declared (leaf-where-from leaf))
142 (conservative-type derived-type)))
143 derived-values-type))
144 derived-values-type)))
146 (defun conservative-type (type)
147 (cond ((or (eq type *universal-type*)
148 (eq type (specifier-type 'list))
149 (eq type (specifier-type 'null)))
152 (specifier-type 'cons))
154 (if (array-type-complexp type)
156 ;; ADJUST-ARRAY may change dimensions, but rank stays same.
158 (let ((old (array-type-dimensions type)))
161 (mapcar (constantly '*) old)))
162 ;; Complexity cannot change.
163 :complexp (array-type-complexp type)
164 ;; Element type cannot change.
165 :element-type (array-type-element-type type)
166 :specialized-element-type (array-type-specialized-element-type type))
167 ;; Simple arrays cannot change at all.
170 ;; Conservative union type is an union of conservative types.
171 (let ((res *empty-type*))
172 (dolist (part (union-type-types type) res)
173 (setf res (type-union res (conservative-type part))))))
177 ;; If the type contains some CONS types, the conservative type contains all
179 (when (types-equal-or-intersect type (specifier-type 'cons))
180 (setf type (type-union type (specifier-type 'cons))))
181 ;; Similarly for non-simple arrays -- it should be possible to preserve
182 ;; more information here, but really...
183 (let ((non-simple-arrays (specifier-type '(and array (not simple-array)))))
184 (when (types-equal-or-intersect type non-simple-arrays)
185 (setf type (type-union type non-simple-arrays))))
188 (defun type-needs-conservation-p (type)
189 (cond ((eq type *universal-type*)
190 ;; Excluding T is necessary, because we do want type derivation to
191 ;; be able to narrow it down in case someone (most like a macro-expansion...)
192 ;; actually declares something as having type T.
194 ((or (cons-type-p type) (and (array-type-p type) (array-type-complexp type)))
195 ;; Covered by the next case as well, but this is a quick test.
197 ((types-equal-or-intersect type (specifier-type '(or cons (and array (not simple-array)))))
200 ;;; If LVAR is an argument of a function, return a type which the
201 ;;; function checks LVAR for.
202 #!-sb-fluid (declaim (inline lvar-externally-checkable-type))
203 (defun lvar-externally-checkable-type (lvar)
204 (or (lvar-%externally-checkable-type lvar)
205 (%lvar-%externally-checkable-type lvar)))
206 (defun %lvar-%externally-checkable-type (lvar)
207 (declare (type lvar lvar))
208 (let ((dest (lvar-dest lvar)))
209 (if (not (and dest (combination-p dest)))
210 ;; TODO: MV-COMBINATION
211 (setf (lvar-%externally-checkable-type lvar) *wild-type*)
212 (let* ((fun (combination-fun dest))
213 (args (combination-args dest))
214 (fun-type (lvar-type fun)))
215 (setf (lvar-%externally-checkable-type fun) *wild-type*)
216 (if (or (not (call-full-like-p dest))
217 (not (fun-type-p fun-type))
218 ;; FUN-TYPE might be (AND FUNCTION (SATISFIES ...)).
219 (fun-type-wild-args fun-type))
222 (setf (lvar-%externally-checkable-type arg)
224 (map-combination-args-and-types
226 (setf (lvar-%externally-checkable-type arg)
227 (acond ((lvar-%externally-checkable-type arg)
228 (values-type-intersection
229 it (coerce-to-values type)))
230 (t (coerce-to-values type)))))
232 (or (lvar-%externally-checkable-type lvar) *wild-type*))
233 #!-sb-fluid(declaim (inline flush-lvar-externally-checkable-type))
234 (defun flush-lvar-externally-checkable-type (lvar)
235 (declare (type lvar lvar))
236 (setf (lvar-%externally-checkable-type lvar) nil))
238 ;;;; interface routines used by optimizers
240 (declaim (inline reoptimize-component))
241 (defun reoptimize-component (component kind)
242 (declare (type component component)
243 (type (member nil :maybe t) kind))
245 (unless (eq (component-reoptimize component) t)
246 (setf (component-reoptimize component) kind)))
248 ;;; This function is called by optimizers to indicate that something
249 ;;; interesting has happened to the value of LVAR. Optimizers must
250 ;;; make sure that they don't call for reoptimization when nothing has
251 ;;; happened, since optimization will fail to terminate.
253 ;;; We clear any cached type for the lvar and set the reoptimize flags
254 ;;; on everything in sight.
255 (defun reoptimize-lvar (lvar)
256 (declare (type (or lvar null) lvar))
258 (setf (lvar-%derived-type lvar) nil)
259 (let ((dest (lvar-dest lvar)))
261 (setf (lvar-reoptimize lvar) t)
262 (setf (node-reoptimize dest) t)
263 (binding* (;; Since this may be called during IR1 conversion,
264 ;; PREV may be missing.
265 (prev (node-prev dest) :exit-if-null)
266 (block (ctran-block prev))
267 (component (block-component block)))
268 (when (typep dest 'cif)
269 (setf (block-test-modified block) t))
270 (setf (block-reoptimize block) t)
271 (reoptimize-component component :maybe))))
273 (setf (block-type-check (node-block node)) t)))
276 (defun reoptimize-lvar-uses (lvar)
277 (declare (type lvar lvar))
279 (setf (node-reoptimize use) t)
280 (setf (block-reoptimize (node-block use)) t)
281 (reoptimize-component (node-component use) :maybe)))
283 ;;; Annotate NODE to indicate that its result has been proven to be
284 ;;; TYPEP to RTYPE. After IR1 conversion has happened, this is the
285 ;;; only correct way to supply information discovered about a node's
286 ;;; type. If you screw with the NODE-DERIVED-TYPE directly, then
287 ;;; information may be lost and reoptimization may not happen.
289 ;;; What we do is intersect RTYPE with NODE's DERIVED-TYPE. If the
290 ;;; intersection is different from the old type, then we do a
291 ;;; REOPTIMIZE-LVAR on the NODE-LVAR.
292 (defun derive-node-type (node rtype &key from-scratch)
293 (declare (type valued-node node) (type ctype rtype))
294 (let* ((initial-type (node-derived-type node))
295 (node-type (if from-scratch
298 (unless (eq initial-type rtype)
299 (let ((int (values-type-intersection node-type rtype))
300 (lvar (node-lvar node)))
301 (when (type/= initial-type int)
302 (when (and *check-consistency*
303 (eq int *empty-type*)
304 (not (eq rtype *empty-type*)))
305 (aver (not from-scratch))
306 (let ((*compiler-error-context* node))
308 "New inferred type ~S conflicts with old type:~
309 ~% ~S~%*** possible internal error? Please report this."
310 (type-specifier rtype) (type-specifier node-type))))
311 (setf (node-derived-type node) int)
312 ;; If the new type consists of only one object, replace the
313 ;; node with a constant reference.
314 (when (and (ref-p node)
315 (lambda-var-p (ref-leaf node)))
316 (let ((type (single-value-type int)))
317 (when (and (member-type-p type)
318 (eql 1 (member-type-size type)))
319 (change-ref-leaf node (find-constant
320 (first (member-type-members type)))))))
321 (reoptimize-lvar lvar)))))
324 ;;; This is similar to DERIVE-NODE-TYPE, but asserts that it is an
325 ;;; error for LVAR's value not to be TYPEP to TYPE. We implement it
326 ;;; splitting off DEST a new CAST node; old LVAR will deliver values
327 ;;; to CAST. If we improve the assertion, we set TYPE-CHECK and
328 ;;; TYPE-ASSERTED to guarantee that the new assertion will be checked.
329 (defun assert-lvar-type (lvar type policy)
330 (declare (type lvar lvar) (type ctype type))
331 (unless (values-subtypep (lvar-derived-type lvar) type)
332 (let ((internal-lvar (make-lvar))
333 (dest (lvar-dest lvar)))
334 (substitute-lvar internal-lvar lvar)
335 (let ((cast (insert-cast-before dest lvar type policy)))
336 (use-lvar cast internal-lvar)
342 ;;; Do one forward pass over COMPONENT, deleting unreachable blocks
343 ;;; and doing IR1 optimizations. We can ignore all blocks that don't
344 ;;; have the REOPTIMIZE flag set. If COMPONENT-REOPTIMIZE is true when
345 ;;; we are done, then another iteration would be beneficial.
346 (defun ir1-optimize (component fastp)
347 (declare (type component component))
348 (setf (component-reoptimize component) nil)
349 (loop with block = (block-next (component-head component))
350 with tail = (component-tail component)
351 for last-block = block
352 until (eq block tail)
354 ;; We delete blocks when there is either no predecessor or the
355 ;; block is in a lambda that has been deleted. These blocks
356 ;; would eventually be deleted by DFO recomputation, but doing
357 ;; it here immediately makes the effect available to IR1
359 ((or (block-delete-p block)
360 (null (block-pred block)))
361 (delete-block-lazily block)
362 (setq block (clean-component component block)))
363 ((eq (functional-kind (block-home-lambda block)) :deleted)
364 ;; Preserve the BLOCK-SUCC invariant that almost every block has
365 ;; one successor (and a block with DELETE-P set is an acceptable
367 (mark-for-deletion block)
368 (setq block (clean-component component block)))
371 (let ((succ (block-succ block)))
372 (unless (singleton-p succ)
375 (let ((last (block-last block)))
378 (flush-dest (if-test last))
379 (when (unlink-node last)
382 (when (maybe-delete-exit last)
385 (unless (join-successor-if-possible block)
388 (when (and (not fastp) (block-reoptimize block) (block-component block))
389 (aver (not (block-delete-p block)))
390 (ir1-optimize-block block))
392 (cond ((and (block-delete-p block) (block-component block))
393 (setq block (clean-component component block)))
394 ((and (block-flush-p block) (block-component block))
395 (flush-dead-code block)))))
396 do (when (eq block last-block)
397 (setq block (block-next block))))
401 ;;; Loop over the nodes in BLOCK, acting on (and clearing) REOPTIMIZE
404 ;;; Note that although they are cleared here, REOPTIMIZE flags might
405 ;;; still be set upon return from this function, meaning that further
406 ;;; optimization is wanted (as a consequence of optimizations we did).
407 (defun ir1-optimize-block (block)
408 (declare (type cblock block))
409 ;; We clear the node and block REOPTIMIZE flags before doing the
410 ;; optimization, not after. This ensures that the node or block will
411 ;; be reoptimized if necessary.
412 (setf (block-reoptimize block) nil)
413 (do-nodes (node nil block :restart-p t)
414 (when (node-reoptimize node)
415 ;; As above, we clear the node REOPTIMIZE flag before optimizing.
416 (setf (node-reoptimize node) nil)
420 ;; With a COMBINATION, we call PROPAGATE-FUN-CHANGE whenever
421 ;; the function changes, and call IR1-OPTIMIZE-COMBINATION if
422 ;; any argument changes.
423 (ir1-optimize-combination node))
425 (ir1-optimize-if node))
427 ;; KLUDGE: We leave the NODE-OPTIMIZE flag set going into
428 ;; IR1-OPTIMIZE-RETURN, since IR1-OPTIMIZE-RETURN wants to
429 ;; clear the flag itself. -- WHN 2002-02-02, quoting original
431 (setf (node-reoptimize node) t)
432 (ir1-optimize-return node))
434 (ir1-optimize-mv-combination node))
436 ;; With an EXIT, we derive the node's type from the VALUE's
438 (let ((value (exit-value node)))
440 (derive-node-type node (lvar-derived-type value)))))
442 ;; PROPAGATE-FROM-SETS can do a better job if NODE-REOPTIMIZE
443 ;; is accurate till the node actually has been reoptimized.
444 (setf (node-reoptimize node) t)
445 (ir1-optimize-set node))
447 (ir1-optimize-cast node)))))
451 ;;; Try to join with a successor block. If we succeed, we return true,
453 (defun join-successor-if-possible (block)
454 (declare (type cblock block))
455 (let ((next (first (block-succ block))))
456 (when (block-start next) ; NEXT is not an END-OF-COMPONENT marker
457 (cond ( ;; We cannot combine with a successor block if:
459 ;; the successor has more than one predecessor;
460 (rest (block-pred next))
461 ;; the successor is the current block (infinite loop);
463 ;; the next block has a different cleanup, and thus
464 ;; we may want to insert cleanup code between the
465 ;; two blocks at some point;
466 (not (eq (block-end-cleanup block)
467 (block-start-cleanup next)))
468 ;; the next block has a different home lambda, and
469 ;; thus the control transfer is a non-local exit.
470 (not (eq (block-home-lambda block)
471 (block-home-lambda next)))
472 ;; Stack analysis phase wants ENTRY to start a block...
473 (entry-p (block-start-node next))
474 (let ((last (block-last block)))
475 (and (valued-node-p last)
476 (awhen (node-lvar last)
478 ;; ... and a DX-allocator to end a block.
479 (lvar-dynamic-extent it)
480 ;; FIXME: This is a partial workaround for bug 303.
481 (consp (lvar-uses it)))))))
484 (join-blocks block next)
487 ;;; Join together two blocks. The code in BLOCK2 is moved into BLOCK1
488 ;;; and BLOCK2 is deleted from the DFO. We combine the optimize flags
489 ;;; for the two blocks so that any indicated optimization gets done.
490 (defun join-blocks (block1 block2)
491 (declare (type cblock block1 block2))
492 (let* ((last1 (block-last block1))
493 (last2 (block-last block2))
494 (succ (block-succ block2))
495 (start2 (block-start block2)))
496 (do ((ctran start2 (node-next (ctran-next ctran))))
498 (setf (ctran-block ctran) block1))
500 (unlink-blocks block1 block2)
502 (unlink-blocks block2 block)
503 (link-blocks block1 block))
505 (setf (ctran-kind start2) :inside-block)
506 (setf (node-next last1) start2)
507 (setf (ctran-use start2) last1)
508 (setf (block-last block1) last2))
510 (setf (block-flags block1)
511 (attributes-union (block-flags block1)
513 (block-attributes type-asserted test-modified)))
515 (let ((next (block-next block2))
516 (prev (block-prev block2)))
517 (setf (block-next prev) next)
518 (setf (block-prev next) prev))
522 ;;; Delete any nodes in BLOCK whose value is unused and which have no
523 ;;; side effects. We can delete sets of lexical variables when the set
524 ;;; variable has no references.
525 (defun flush-dead-code (block)
526 (declare (type cblock block))
527 (setf (block-flush-p block) nil)
528 (do-nodes-backwards (node lvar block :restart-p t)
535 (when (flushable-combination-p node)
536 (flush-combination node)))
538 (when (eq (basic-combination-kind node) :local)
539 (let ((fun (combination-lambda node)))
540 (when (dolist (var (lambda-vars fun) t)
541 (when (or (leaf-refs var)
542 (lambda-var-sets var))
544 (flush-dest (first (basic-combination-args node)))
547 (let ((value (exit-value node)))
550 (setf (exit-value node) nil))))
552 (let ((var (set-var node)))
553 (when (and (lambda-var-p var)
554 (null (leaf-refs var)))
555 (flush-dest (set-value node))
556 (setf (basic-var-sets var)
557 (delq node (basic-var-sets var)))
558 (unlink-node node))))
560 (unless (cast-type-check node)
561 (flush-dest (cast-value node))
562 (unlink-node node))))))
566 ;;;; local call return type propagation
568 ;;; This function is called on RETURN nodes that have their REOPTIMIZE
569 ;;; flag set. It iterates over the uses of the RESULT, looking for
570 ;;; interesting stuff to update the TAIL-SET. If a use isn't a local
571 ;;; call, then we union its type together with the types of other such
572 ;;; uses. We assign to the RETURN-RESULT-TYPE the intersection of this
573 ;;; type with the RESULT's asserted type. We can make this
574 ;;; intersection now (potentially before type checking) because this
575 ;;; assertion on the result will eventually be checked (if
578 ;;; We call MAYBE-CONVERT-TAIL-LOCAL-CALL on each local non-MV
579 ;;; combination, which may change the successor of the call to be the
580 ;;; called function, and if so, checks if the call can become an
581 ;;; assignment. If we convert to an assignment, we abort, since the
582 ;;; RETURN has been deleted.
583 (defun find-result-type (node)
584 (declare (type creturn node))
585 (let ((result (return-result node)))
586 (collect ((use-union *empty-type* values-type-union))
587 (do-uses (use result)
588 (let ((use-home (node-home-lambda use)))
589 (cond ((or (eq (functional-kind use-home) :deleted)
590 (block-delete-p (node-block use))))
591 ((and (basic-combination-p use)
592 (eq (basic-combination-kind use) :local))
593 (aver (eq (lambda-tail-set use-home)
594 (lambda-tail-set (combination-lambda use))))
595 (when (combination-p use)
596 (when (nth-value 1 (maybe-convert-tail-local-call use))
597 (return-from find-result-type t))))
599 (use-union (node-derived-type use))))))
601 ;; (values-type-intersection
602 ;; (continuation-asserted-type result) ; FIXME -- APD, 2002-01-26
606 (setf (return-result-type node) int))))
609 ;;; Do stuff to realize that something has changed about the value
610 ;;; delivered to a return node. Since we consider the return values of
611 ;;; all functions in the tail set to be equivalent, this amounts to
612 ;;; bringing the entire tail set up to date. We iterate over the
613 ;;; returns for all the functions in the tail set, reanalyzing them
614 ;;; all (not treating NODE specially.)
616 ;;; When we are done, we check whether the new type is different from
617 ;;; the old TAIL-SET-TYPE. If so, we set the type and also reoptimize
618 ;;; all the lvars for references to functions in the tail set. This
619 ;;; will cause IR1-OPTIMIZE-COMBINATION to derive the new type as the
620 ;;; results of the calls.
621 (defun ir1-optimize-return (node)
622 (declare (type creturn node))
625 (let* ((tails (lambda-tail-set (return-lambda node)))
626 (funs (tail-set-funs tails)))
627 (collect ((res *empty-type* values-type-union))
629 (let ((return (lambda-return fun)))
631 (when (node-reoptimize return)
632 (setf (node-reoptimize return) nil)
633 (when (find-result-type return)
635 (res (return-result-type return)))))
637 (when (type/= (res) (tail-set-type tails))
638 (setf (tail-set-type tails) (res))
639 (dolist (fun (tail-set-funs tails))
640 (dolist (ref (leaf-refs fun))
641 (reoptimize-lvar (node-lvar ref))))))))
647 ;;; Utility: return T if both argument cblocks are equivalent. For now,
648 ;;; detect only blocks that read the same leaf into the same lvar, and
649 ;;; continue to the same block.
650 (defun cblocks-equivalent-p (x y)
651 (declare (type cblock x y))
652 (and (ref-p (block-start-node x))
653 (eq (block-last x) (block-start-node x))
655 (ref-p (block-start-node y))
656 (eq (block-last y) (block-start-node y))
658 (equal (block-succ x) (block-succ y))
659 (eql (ref-lvar (block-start-node x)) (ref-lvar (block-start-node y)))
660 (eql (ref-leaf (block-start-node x)) (ref-leaf (block-start-node y)))))
662 ;;; Check whether the predicate is known to be true or false,
663 ;;; deleting the IF node in favor of the appropriate branch when this
665 ;;; Similarly, when both branches are equivalent, branch directly to either
667 ;;; Also, if the test has multiple uses, replicate the node when possible...
668 ;;; in fact, splice in direct jumps to the right branch if possible.
669 (defun ir1-optimize-if (node)
670 (declare (type cif node))
671 (let ((test (if-test node))
672 (block (node-block node)))
673 (let* ((type (lvar-type test))
674 (consequent (if-consequent node))
675 (alternative (if-alternative node))
677 (cond ((constant-lvar-p test)
678 (if (lvar-value test) alternative consequent))
679 ((not (types-equal-or-intersect type (specifier-type 'null)))
681 ((type= type (specifier-type 'null))
683 ((or (eq consequent alternative) ; Can this happen?
684 (cblocks-equivalent-p alternative consequent))
687 (kill-if-branch-1 node test block victim)
688 (return-from ir1-optimize-if (values))))
689 (tension-if-if-1 node test block)
690 (duplicate-if-if-1 node test block)
693 ;; When we know that we only have a single successor, kill the victim
694 ;; ... unless the victim and the remaining successor are the same.
695 (defun kill-if-branch-1 (node test block victim)
696 (declare (type cif node))
698 (when (rest (block-succ block))
699 (unlink-blocks block victim))
700 (setf (component-reanalyze (node-component node)) t)
703 ;; When if/if conversion would leave (if ... (if nil ...)) or
704 ;; (if ... (if not-nil ...)), splice the correct successor right
706 (defun tension-if-if-1 (node test block)
707 (when (and (eq (block-start-node block) node)
708 (listp (lvar-uses test)))
710 (when (immediately-used-p test use)
711 (let* ((type (single-value-type (node-derived-type use)))
712 (target (if (type= type (specifier-type 'null))
713 (if-alternative node)
714 (multiple-value-bind (typep surep)
716 (and (not typep) surep
717 (if-consequent node))))))
719 (let ((pred (node-block use)))
720 (cond ((listp (lvar-uses test))
721 (change-block-successor pred block target)
722 (delete-lvar-use use))
724 ;; only one use left. Just kill the now-useless
725 ;; branch to avoid spurious code deletion notes.
726 (aver (rest (block-succ block)))
729 (if (eql target (if-alternative node))
731 (if-alternative node)))
732 (return-from tension-if-if-1))))))))))
734 ;; Finally, duplicate EQ-nil tests
735 (defun duplicate-if-if-1 (node test block)
736 (when (and (eq (block-start-node block) node)
737 (listp (lvar-uses test)))
739 (when (immediately-used-p test use)
740 (convert-if-if use node)
741 ;; leave the last use as is, instead of replacing
742 ;; the (singly-referenced) CIF node with a duplicate.
743 (when (not (listp (lvar-uses test))) (return))))))
745 ;;; Create a new copy of an IF node that tests the value of the node
746 ;;; USE. The test must have >1 use, and must be immediately used by
747 ;;; USE. NODE must be the only node in its block (implying that
748 ;;; block-start = if-test).
750 ;;; This optimization has an effect semantically similar to the
751 ;;; source-to-source transformation:
752 ;;; (IF (IF A B C) D E) ==>
753 ;;; (IF A (IF B D E) (IF C D E))
755 ;;; We clobber the NODE-SOURCE-PATH of both the original and the new
756 ;;; node so that dead code deletion notes will definitely not consider
757 ;;; either node to be part of the original source. One node might
758 ;;; become unreachable, resulting in a spurious note.
759 (defun convert-if-if (use node)
760 (declare (type node use) (type cif node))
761 (with-ir1-environment-from-node node
762 (let* ((block (node-block node))
763 (test (if-test node))
764 (cblock (if-consequent node))
765 (ablock (if-alternative node))
766 (use-block (node-block use))
767 (new-ctran (make-ctran))
768 (new-lvar (make-lvar))
769 (new-node (make-if :test new-lvar
771 :alternative ablock))
772 (new-block (ctran-starts-block new-ctran)))
773 (link-node-to-previous-ctran new-node new-ctran)
774 (setf (lvar-dest new-lvar) new-node)
775 (setf (block-last new-block) new-node)
777 (unlink-blocks use-block block)
778 (%delete-lvar-use use)
779 (add-lvar-use use new-lvar)
780 (link-blocks use-block new-block)
782 (link-blocks new-block cblock)
783 (link-blocks new-block ablock)
785 (push "<IF Duplication>" (node-source-path node))
786 (push "<IF Duplication>" (node-source-path new-node))
788 (reoptimize-lvar test)
789 (reoptimize-lvar new-lvar)
790 (setf (component-reanalyze *current-component*) t)))
793 ;;;; exit IR1 optimization
795 ;;; This function attempts to delete an exit node, returning true if
796 ;;; it deletes the block as a consequence:
797 ;;; -- If the exit is degenerate (has no ENTRY), then we don't do
798 ;;; anything, since there is nothing to be done.
799 ;;; -- If the exit node and its ENTRY have the same home lambda then
800 ;;; we know the exit is local, and can delete the exit. We change
801 ;;; uses of the Exit-Value to be uses of the original lvar,
802 ;;; then unlink the node. If the exit is to a TR context, then we
803 ;;; must do MERGE-TAIL-SETS on any local calls which delivered
804 ;;; their value to this exit.
805 ;;; -- If there is no value (as in a GO), then we skip the value
808 ;;; This function is also called by environment analysis, since it
809 ;;; wants all exits to be optimized even if normal optimization was
811 (defun maybe-delete-exit (node)
812 (declare (type exit node))
813 (let ((value (exit-value node))
814 (entry (exit-entry node)))
816 (eq (node-home-lambda node) (node-home-lambda entry)))
817 (setf (entry-exits entry) (delq node (entry-exits entry)))
819 (delete-filter node (node-lvar node) value)
820 (unlink-node node)))))
823 ;;;; combination IR1 optimization
825 ;;; Report as we try each transform?
827 (defvar *show-transforms-p* nil)
829 (defun check-important-result (node info)
830 (when (and (null (node-lvar node))
831 (ir1-attributep (fun-info-attributes info) important-result))
832 (let ((*compiler-error-context* node))
834 "The return value of ~A should not be discarded."
835 (lvar-fun-name (basic-combination-fun node))))))
837 ;;; Do IR1 optimizations on a COMBINATION node.
838 (declaim (ftype (function (combination) (values)) ir1-optimize-combination))
839 (defun ir1-optimize-combination (node)
840 (when (lvar-reoptimize (basic-combination-fun node))
841 (propagate-fun-change node)
842 (maybe-terminate-block node nil))
843 (let ((args (basic-combination-args node))
844 (kind (basic-combination-kind node))
845 (info (basic-combination-fun-info node)))
848 (let ((fun (combination-lambda node)))
849 (if (eq (functional-kind fun) :let)
850 (propagate-let-args node fun)
851 (propagate-local-call-args node fun))))
855 (setf (lvar-reoptimize arg) nil))))
859 (setf (lvar-reoptimize arg) nil)))
861 (check-important-result node info)
862 (let ((fun (fun-info-destroyed-constant-args info)))
864 (let ((destroyed-constant-args (funcall fun args)))
865 (when destroyed-constant-args
866 (let ((*compiler-error-context* node))
867 (warn 'constant-modified
868 :fun-name (lvar-fun-name
869 (basic-combination-fun node)))
870 (setf (basic-combination-kind node) :error)
871 (return-from ir1-optimize-combination))))))
872 (let ((fun (fun-info-derive-type info)))
874 (let ((res (funcall fun node)))
876 (derive-node-type node (coerce-to-values res))
877 (maybe-terminate-block node nil))))))
879 ;; Check against the DEFINED-TYPE unless TYPE is already good.
880 (let* ((fun (basic-combination-fun node))
881 (uses (lvar-uses fun))
882 (leaf (when (ref-p uses) (ref-leaf uses))))
883 (multiple-value-bind (type defined-type)
884 (if (global-var-p leaf)
885 (values (leaf-type leaf) (leaf-defined-type leaf))
887 (when (and (not (fun-type-p type)) (fun-type-p defined-type))
888 (validate-call-type node type leaf)))))))
893 (setf (lvar-reoptimize arg) nil)))
894 (check-important-result node info)
895 (let ((fun (fun-info-destroyed-constant-args info)))
897 ;; If somebody is really sure that they want to modify
898 ;; constants, let them.
899 (policy node (> check-constant-modification 0)))
900 (let ((destroyed-constant-args (funcall fun args)))
901 (when destroyed-constant-args
902 (let ((*compiler-error-context* node))
903 (warn 'constant-modified
904 :fun-name (lvar-fun-name
905 (basic-combination-fun node)))
906 (setf (basic-combination-kind node) :error)
907 (return-from ir1-optimize-combination))))))
909 (let ((attr (fun-info-attributes info)))
910 (when (and (ir1-attributep attr foldable)
911 ;; KLUDGE: The next test could be made more sensitive,
912 ;; only suppressing constant-folding of functions with
913 ;; CALL attributes when they're actually passed
914 ;; function arguments. -- WHN 19990918
915 (not (ir1-attributep attr call))
916 (every #'constant-lvar-p args)
918 (constant-fold-call node)
919 (return-from ir1-optimize-combination)))
921 (let ((fun (fun-info-derive-type info)))
923 (let ((res (funcall fun node)))
925 (derive-node-type node (coerce-to-values res))
926 (maybe-terminate-block node nil)))))
928 (let ((fun (fun-info-optimizer info)))
929 (unless (and fun (funcall fun node))
930 ;; First give the VM a peek at the call
931 (multiple-value-bind (style transform)
932 (combination-implementation-style node)
935 ;; The VM knows how to handle this.
938 ;; The VM mostly knows how to handle this. We need
939 ;; to massage the call slightly, though.
940 (transform-call node transform (combination-fun-source-name node)))
942 ;; Let transforms have a crack at it.
943 (dolist (x (fun-info-transforms info))
945 (when *show-transforms-p*
946 (let* ((lvar (basic-combination-fun node))
947 (fname (lvar-fun-name lvar t)))
948 (/show "trying transform" x (transform-function x) "for" fname)))
949 (unless (ir1-transform node x)
951 (when *show-transforms-p*
952 (/show "quitting because IR1-TRANSFORM result was NIL"))
957 (defun xep-tail-combination-p (node)
958 (and (combination-p node)
959 (let* ((lvar (combination-lvar node))
960 (dest (when (lvar-p lvar) (lvar-dest lvar)))
961 (lambda (when (return-p dest) (return-lambda dest))))
962 (and (lambda-p lambda)
963 (eq :external (lambda-kind lambda))))))
965 ;;; If NODE doesn't return (i.e. return type is NIL), then terminate
966 ;;; the block there, and link it to the component tail.
968 ;;; Except when called during IR1 convertion, we delete the
969 ;;; continuation if it has no other uses. (If it does have other uses,
972 ;;; Termination on the basis of a continuation type is
974 ;;; -- The continuation is deleted (hence the assertion is spurious), or
975 ;;; -- We are in IR1 conversion (where THE assertions are subject to
976 ;;; weakening.) FIXME: Now THE assertions are not weakened, but new
977 ;;; uses can(?) be added later. -- APD, 2003-07-17
979 ;;; Why do we need to consider LVAR type? -- APD, 2003-07-30
980 (defun maybe-terminate-block (node ir1-converting-not-optimizing-p)
981 (declare (type (or basic-combination cast ref) node))
982 (let* ((block (node-block node))
983 (lvar (node-lvar node))
984 (ctran (node-next node))
985 (tail (component-tail (block-component block)))
986 (succ (first (block-succ block))))
987 (declare (ignore lvar))
988 (unless (or (and (eq node (block-last block)) (eq succ tail))
989 (block-delete-p block))
990 ;; Even if the combination will never return, don't terminate if this
991 ;; is the tail call of a XEP: doing that would inhibit TCO.
992 (when (and (eq (node-derived-type node) *empty-type*)
993 (not (xep-tail-combination-p node)))
994 (cond (ir1-converting-not-optimizing-p
997 (aver (eq (block-last block) node)))
999 (setf (block-last block) node)
1000 (setf (ctran-use ctran) nil)
1001 (setf (ctran-kind ctran) :unused)
1002 (setf (ctran-block ctran) nil)
1003 (setf (node-next node) nil)
1004 (link-blocks block (ctran-starts-block ctran)))))
1006 (node-ends-block node)))
1008 (let ((succ (first (block-succ block))))
1009 (unlink-blocks block succ)
1010 (setf (component-reanalyze (block-component block)) t)
1011 (aver (not (block-succ block)))
1012 (link-blocks block tail)
1013 (cond (ir1-converting-not-optimizing-p
1014 (%delete-lvar-use node))
1015 (t (delete-lvar-use node)
1016 (when (null (block-pred succ))
1017 (mark-for-deletion succ)))))
1020 ;;; This is called both by IR1 conversion and IR1 optimization when
1021 ;;; they have verified the type signature for the call, and are
1022 ;;; wondering if something should be done to special-case the call. If
1023 ;;; CALL is a call to a global function, then see whether it defined
1025 ;;; -- If a DEFINED-FUN should be inline expanded, then convert
1026 ;;; the expansion and change the call to call it. Expansion is
1027 ;;; enabled if :INLINE or if SPACE=0. If the FUNCTIONAL slot is
1028 ;;; true, we never expand, since this function has already been
1029 ;;; converted. Local call analysis will duplicate the definition
1030 ;;; if necessary. We claim that the parent form is LABELS for
1031 ;;; context declarations, since we don't want it to be considered
1032 ;;; a real global function.
1033 ;;; -- If it is a known function, mark it as such by setting the KIND.
1035 ;;; We return the leaf referenced (NIL if not a leaf) and the
1036 ;;; FUN-INFO assigned.
1037 (defun recognize-known-call (call ir1-converting-not-optimizing-p)
1038 (declare (type combination call))
1039 (let* ((ref (lvar-uses (basic-combination-fun call)))
1040 (leaf (when (ref-p ref) (ref-leaf ref)))
1041 (inlinep (if (defined-fun-p leaf)
1042 (defined-fun-inlinep leaf)
1045 ((eq inlinep :notinline)
1046 (let ((info (info :function :info (leaf-source-name leaf))))
1048 (setf (basic-combination-fun-info call) info))
1050 ((not (and (global-var-p leaf)
1051 (eq (global-var-kind leaf) :global-function)))
1053 ((and (ecase inlinep
1056 ((nil :maybe-inline) (policy call (zerop space))))
1057 (defined-fun-p leaf)
1058 (defined-fun-inline-expansion leaf)
1059 (inline-expansion-ok call))
1060 ;; Inline: if the function has already been converted at another call
1061 ;; site in this component, we point this REF to the functional. If not,
1062 ;; we convert the expansion.
1064 ;; For :INLINE case local call analysis will copy the expansion later,
1065 ;; but for :MAYBE-INLINE and NIL cases we only get one copy of the
1066 ;; expansion per component.
1068 ;; FIXME: We also convert in :INLINE & FUNCTIONAL-KIND case below. What
1071 (let* ((name (leaf-source-name leaf))
1072 (res (ir1-convert-inline-expansion
1074 (defined-fun-inline-expansion leaf)
1077 (info :function :info name))))
1078 ;; Allow backward references to this function from following
1079 ;; forms. (Reused only if policy matches.)
1080 (push res (defined-fun-functionals leaf))
1081 (change-ref-leaf ref res))))
1082 (let ((fun (defined-fun-functional leaf)))
1084 (and (eq inlinep :inline) (functional-kind fun)))
1086 (if ir1-converting-not-optimizing-p
1088 (with-ir1-environment-from-node call
1090 (locall-analyze-component *current-component*)))
1091 ;; If we've already converted, change ref to the converted
1093 (change-ref-leaf ref fun))))
1094 (values (ref-leaf ref) nil))
1096 (let ((info (info :function :info (leaf-source-name leaf))))
1100 (setf (basic-combination-kind call) :known)
1101 (setf (basic-combination-fun-info call) info)))
1102 (values leaf nil)))))))
1104 ;;; Check whether CALL satisfies TYPE. If so, apply the type to the
1105 ;;; call, and do MAYBE-TERMINATE-BLOCK and return the values of
1106 ;;; RECOGNIZE-KNOWN-CALL. If an error, set the combination kind and
1107 ;;; return NIL, NIL. If the type is just FUNCTION, then skip the
1108 ;;; syntax check, arg/result type processing, but still call
1109 ;;; RECOGNIZE-KNOWN-CALL, since the call might be to a known lambda,
1110 ;;; and that checking is done by local call analysis.
1111 (defun validate-call-type (call type fun &optional ir1-converting-not-optimizing-p)
1112 (declare (type combination call) (type ctype type))
1113 (let* ((where (when fun (leaf-where-from fun)))
1114 (same-file-p (eq :defined-here where)))
1115 (cond ((not (fun-type-p type))
1116 (aver (multiple-value-bind (val win)
1117 (csubtypep type (specifier-type 'function))
1118 (or val (not win))))
1119 ;; Using the defined-type too early is a bit of a waste: during
1120 ;; conversion we cannot use the untrusted ASSERT-CALL-TYPE, etc.
1121 (when (and fun (not ir1-converting-not-optimizing-p))
1122 (let ((defined-type (leaf-defined-type fun)))
1123 (when (and (fun-type-p defined-type)
1124 (neq fun (combination-type-validated-for-leaf call)))
1125 ;; Don't validate multiple times against the same leaf --
1126 ;; it doesn't add any information, but may generate the same warning
1128 (setf (combination-type-validated-for-leaf call) fun)
1129 (when (and (valid-fun-use call defined-type
1130 :argument-test #'always-subtypep
1132 :lossage-fun (if same-file-p
1134 #'compiler-style-warn)
1135 :unwinnage-fun #'compiler-notify)
1137 (assert-call-type call defined-type nil)
1138 (maybe-terminate-block call ir1-converting-not-optimizing-p)))))
1139 (recognize-known-call call ir1-converting-not-optimizing-p))
1140 ((valid-fun-use call type
1141 :argument-test #'always-subtypep
1143 :lossage-fun #'compiler-warn
1144 :unwinnage-fun #'compiler-notify)
1145 (assert-call-type call type)
1146 (maybe-terminate-block call ir1-converting-not-optimizing-p)
1147 (recognize-known-call call ir1-converting-not-optimizing-p))
1149 (setf (combination-kind call) :error)
1150 (values nil nil)))))
1152 ;;; This is called by IR1-OPTIMIZE when the function for a call has
1153 ;;; changed. If the call is local, we try to LET-convert it, and
1154 ;;; derive the result type. If it is a :FULL call, we validate it
1155 ;;; against the type, which recognizes known calls, does inline
1156 ;;; expansion, etc. If a call to a predicate in a non-conditional
1157 ;;; position or to a function with a source transform, then we
1158 ;;; reconvert the form to give IR1 another chance.
1159 (defun propagate-fun-change (call)
1160 (declare (type combination call))
1161 (let ((*compiler-error-context* call)
1162 (fun-lvar (basic-combination-fun call)))
1163 (setf (lvar-reoptimize fun-lvar) nil)
1164 (case (combination-kind call)
1166 (let ((fun (combination-lambda call)))
1167 (maybe-let-convert fun)
1168 (unless (member (functional-kind fun) '(:let :assignment :deleted))
1169 (derive-node-type call (tail-set-type (lambda-tail-set fun))))))
1171 (multiple-value-bind (leaf info)
1172 (let* ((uses (lvar-uses fun-lvar))
1173 (leaf (when (ref-p uses) (ref-leaf uses))))
1174 (validate-call-type call (lvar-type fun-lvar) leaf))
1175 (cond ((functional-p leaf)
1176 (convert-call-if-possible
1177 (lvar-uses (basic-combination-fun call))
1180 ((and (global-var-p leaf)
1181 (eq (global-var-kind leaf) :global-function)
1182 (leaf-has-source-name-p leaf)
1183 (or (info :function :source-transform (leaf-source-name leaf))
1185 (ir1-attributep (fun-info-attributes info)
1187 (let ((lvar (node-lvar call)))
1188 (and lvar (not (if-p (lvar-dest lvar))))))))
1189 (let ((name (leaf-source-name leaf))
1190 (dummies (make-gensym-list
1191 (length (combination-args call)))))
1192 (transform-call call
1194 (,@(if (symbolp name)
1198 (leaf-source-name leaf)))))))))
1201 ;;;; known function optimization
1203 ;;; Add a failed optimization note to FAILED-OPTIMZATIONS for NODE,
1204 ;;; FUN and ARGS. If there is already a note for NODE and TRANSFORM,
1205 ;;; replace it, otherwise add a new one.
1206 (defun record-optimization-failure (node transform args)
1207 (declare (type combination node) (type transform transform)
1208 (type (or fun-type list) args))
1209 (let* ((table (component-failed-optimizations *component-being-compiled*))
1210 (found (assoc transform (gethash node table))))
1212 (setf (cdr found) args)
1213 (push (cons transform args) (gethash node table))))
1216 ;;; Attempt to transform NODE using TRANSFORM-FUNCTION, subject to the
1217 ;;; call type constraint TRANSFORM-TYPE. If we are inhibited from
1218 ;;; doing the transform for some reason and FLAME is true, then we
1219 ;;; make a note of the message in FAILED-OPTIMIZATIONS for IR1
1220 ;;; finalize to pick up. We return true if the transform failed, and
1221 ;;; thus further transformation should be attempted. We return false
1222 ;;; if either the transform succeeded or was aborted.
1223 (defun ir1-transform (node transform)
1224 (declare (type combination node) (type transform transform))
1225 (let* ((type (transform-type transform))
1226 (fun (transform-function transform))
1227 (constrained (fun-type-p type))
1228 (table (component-failed-optimizations *component-being-compiled*))
1229 (flame (if (transform-important transform)
1230 (policy node (>= speed inhibit-warnings))
1231 (policy node (> speed inhibit-warnings))))
1232 (*compiler-error-context* node))
1233 (cond ((or (not constrained)
1234 (valid-fun-use node type))
1235 (multiple-value-bind (severity args)
1236 (catch 'give-up-ir1-transform
1237 (transform-call node
1239 (combination-fun-source-name node))
1243 (remhash node table)
1246 (setf (combination-kind node) :error)
1248 (apply #'warn args))
1249 (remhash node table)
1254 (record-optimization-failure node transform args))
1255 (setf (gethash node table)
1256 (remove transform (gethash node table) :key #'car)))
1259 (remhash node table)
1264 :argument-test #'types-equal-or-intersect
1265 :result-test #'values-types-equal-or-intersect))
1266 (record-optimization-failure node transform type)
1271 ;;; When we don't like an IR1 transform, we throw the severity/reason
1274 ;;; GIVE-UP-IR1-TRANSFORM is used to throw out of an IR1 transform,
1275 ;;; aborting this attempt to transform the call, but admitting the
1276 ;;; possibility that this or some other transform will later succeed.
1277 ;;; If arguments are supplied, they are format arguments for an
1278 ;;; efficiency note.
1280 ;;; ABORT-IR1-TRANSFORM is used to throw out of an IR1 transform and
1281 ;;; force a normal call to the function at run time. No further
1282 ;;; optimizations will be attempted.
1284 ;;; DELAY-IR1-TRANSFORM is used to throw out of an IR1 transform, and
1285 ;;; delay the transform on the node until later. REASONS specifies
1286 ;;; when the transform will be later retried. The :OPTIMIZE reason
1287 ;;; causes the transform to be delayed until after the current IR1
1288 ;;; optimization pass. The :CONSTRAINT reason causes the transform to
1289 ;;; be delayed until after constraint propagation.
1291 ;;; FIXME: Now (0.6.11.44) that there are 4 variants of this (GIVE-UP,
1292 ;;; ABORT, DELAY/:OPTIMIZE, DELAY/:CONSTRAINT) and we're starting to
1293 ;;; do CASE operations on the various REASON values, it might be a
1294 ;;; good idea to go OO, representing the reasons by objects, using
1295 ;;; CLOS methods on the objects instead of CASE, and (possibly) using
1296 ;;; SIGNAL instead of THROW.
1297 (declaim (ftype (function (&rest t) nil) give-up-ir1-transform))
1298 (defun give-up-ir1-transform (&rest args)
1299 (throw 'give-up-ir1-transform (values :failure args)))
1300 (defun abort-ir1-transform (&rest args)
1301 (throw 'give-up-ir1-transform (values :aborted args)))
1302 (defun delay-ir1-transform (node &rest reasons)
1303 (let ((assoc (assoc node *delayed-ir1-transforms*)))
1305 (setf *delayed-ir1-transforms*
1306 (acons node reasons *delayed-ir1-transforms*))
1307 (throw 'give-up-ir1-transform :delayed))
1309 (dolist (reason reasons)
1310 (pushnew reason (cdr assoc)))
1311 (throw 'give-up-ir1-transform :delayed)))))
1313 ;;; Clear any delayed transform with no reasons - these should have
1314 ;;; been tried in the last pass. Then remove the reason from the
1315 ;;; delayed transform reasons, and if any become empty then set
1316 ;;; reoptimize flags for the node. Return true if any transforms are
1318 (defun retry-delayed-ir1-transforms (reason)
1319 (setf *delayed-ir1-transforms*
1320 (remove-if-not #'cdr *delayed-ir1-transforms*))
1321 (let ((reoptimize nil))
1322 (dolist (assoc *delayed-ir1-transforms*)
1323 (let ((reasons (remove reason (cdr assoc))))
1324 (setf (cdr assoc) reasons)
1326 (let ((node (car assoc)))
1327 (unless (node-deleted node)
1329 (setf (node-reoptimize node) t)
1330 (let ((block (node-block node)))
1331 (setf (block-reoptimize block) t)
1332 (reoptimize-component (block-component block) :maybe)))))))
1335 ;;; Take the lambda-expression RES, IR1 convert it in the proper
1336 ;;; environment, and then install it as the function for the call
1337 ;;; NODE. We do local call analysis so that the new function is
1338 ;;; integrated into the control flow.
1340 ;;; We require the original function source name in order to generate
1341 ;;; a meaningful debug name for the lambda we set up. (It'd be
1342 ;;; possible to do this starting from debug names as well as source
1343 ;;; names, but as of sbcl-0.7.1.5, there was no need for this
1344 ;;; generality, since source names are always known to our callers.)
1345 (defun transform-call (call res source-name)
1346 (declare (type combination call) (list res))
1347 (aver (and (legal-fun-name-p source-name)
1348 (not (eql source-name '.anonymous.))))
1349 (node-ends-block call)
1350 ;; The internal variables of a transform are not going to be
1351 ;; interesting to the debugger, so there's no sense in
1352 ;; suppressing the substitution of variables with only one use
1353 ;; (the extra variables can slow down constraint propagation).
1355 ;; This needs to be done before the WITH-IR1-ENVIRONMENT-FROM-NODE,
1356 ;; so that it will bind *LEXENV* to the right environment.
1357 (setf (combination-lexenv call)
1358 (make-lexenv :default (combination-lexenv call)
1359 :policy (process-optimize-decl
1361 (preserve-single-use-debug-variables 0))
1363 (combination-lexenv call)))))
1364 (with-ir1-environment-from-node call
1365 (with-component-last-block (*current-component*
1366 (block-next (node-block call)))
1368 (let ((new-fun (ir1-convert-inline-lambda
1370 :debug-name (debug-name 'lambda-inlined source-name)
1372 (ref (lvar-use (combination-fun call))))
1373 (change-ref-leaf ref new-fun)
1374 (setf (combination-kind call) :full)
1375 (locall-analyze-component *current-component*))))
1378 ;;; Replace a call to a foldable function of constant arguments with
1379 ;;; the result of evaluating the form. If there is an error during the
1380 ;;; evaluation, we give a warning and leave the call alone, making the
1381 ;;; call a :ERROR call.
1383 ;;; If there is more than one value, then we transform the call into a
1385 (defun constant-fold-call (call)
1386 (let ((args (mapcar #'lvar-value (combination-args call)))
1387 (fun-name (combination-fun-source-name call)))
1388 (multiple-value-bind (values win)
1389 (careful-call fun-name
1392 ;; Note: CMU CL had COMPILER-WARN here, and that
1393 ;; seems more natural, but it's probably not.
1395 ;; It's especially not while bug 173 exists:
1398 ;; (UNLESS (OR UNSAFE? (<= END SIZE)))
1400 ;; can cause constant-folding TYPE-ERRORs (in
1401 ;; #'<=) when END can be proved to be NIL, even
1402 ;; though the code is perfectly legal and safe
1403 ;; because a NIL value of END means that the
1404 ;; #'<= will never be executed.
1406 ;; Moreover, even without bug 173,
1407 ;; quite-possibly-valid code like
1408 ;; (COND ((NONINLINED-PREDICATE END)
1409 ;; (UNLESS (<= END SIZE))
1411 ;; (where NONINLINED-PREDICATE is something the
1412 ;; compiler can't do at compile time, but which
1413 ;; turns out to make the #'<= expression
1414 ;; unreachable when END=NIL) could cause errors
1415 ;; when the compiler tries to constant-fold (<=
1418 ;; So, with or without bug 173, it'd be
1419 ;; unnecessarily evil to do a full
1420 ;; COMPILER-WARNING (and thus return FAILURE-P=T
1421 ;; from COMPILE-FILE) for legal code, so we we
1422 ;; use a wimpier COMPILE-STYLE-WARNING instead.
1423 #-sb-xc-host #'compiler-style-warn
1424 ;; On the other hand, for code we control, we
1425 ;; should be able to work around any bug
1426 ;; 173-related problems, and in particular we
1427 ;; want to be alerted to calls to our own
1428 ;; functions which aren't being folded away; a
1429 ;; COMPILER-WARNING is butch enough to stop the
1430 ;; SBCL build itself in its tracks.
1431 #+sb-xc-host #'compiler-warn
1434 (setf (combination-kind call) :error))
1435 ((and (proper-list-of-length-p values 1))
1436 (with-ir1-environment-from-node call
1437 (let* ((lvar (node-lvar call))
1438 (prev (node-prev call))
1439 (intermediate-ctran (make-ctran)))
1440 (%delete-lvar-use call)
1441 (setf (ctran-next prev) nil)
1442 (setf (node-prev call) nil)
1443 (reference-constant prev intermediate-ctran lvar
1445 (link-node-to-previous-ctran call intermediate-ctran)
1446 (reoptimize-lvar lvar)
1447 (flush-combination call))))
1448 (t (let ((dummies (make-gensym-list (length args))))
1452 (declare (ignore ,@dummies))
1453 (values ,@(mapcar (lambda (x) `',x) values)))
1457 ;;;; local call optimization
1459 ;;; Propagate TYPE to LEAF and its REFS, marking things changed.
1461 ;;; If the leaf type is a function type, then just leave it alone, since TYPE
1462 ;;; is never going to be more specific than that (and TYPE-INTERSECTION would
1465 ;;; Also, if the type is one requiring special care don't touch it if the leaf
1466 ;;; has multiple references -- otherwise LVAR-CONSERVATIVE-TYPE is screwed.
1467 (defun propagate-to-refs (leaf type)
1468 (declare (type leaf leaf) (type ctype type))
1469 (let ((var-type (leaf-type leaf))
1470 (refs (leaf-refs leaf)))
1471 (unless (or (fun-type-p var-type)
1473 (eq :declared (leaf-where-from leaf))
1474 (type-needs-conservation-p var-type)))
1475 (let ((int (type-approx-intersection2 var-type type)))
1476 (when (type/= int var-type)
1477 (setf (leaf-type leaf) int)
1478 (let ((s-int (make-single-value-type int)))
1480 (derive-node-type ref s-int)
1481 ;; KLUDGE: LET var substitution
1482 (let* ((lvar (node-lvar ref)))
1483 (when (and lvar (combination-p (lvar-dest lvar)))
1484 (reoptimize-lvar lvar)))))))
1487 ;;; Iteration variable: exactly one SETQ of the form:
1489 ;;; (let ((var initial))
1491 ;;; (setq var (+ var step))
1493 (defun maybe-infer-iteration-var-type (var initial-type)
1494 (binding* ((sets (lambda-var-sets var) :exit-if-null)
1496 (() (null (rest sets)) :exit-if-null)
1497 (set-use (principal-lvar-use (set-value set)))
1498 (() (and (combination-p set-use)
1499 (eq (combination-kind set-use) :known)
1500 (fun-info-p (combination-fun-info set-use))
1501 (not (node-to-be-deleted-p set-use))
1502 (or (eq (combination-fun-source-name set-use) '+)
1503 (eq (combination-fun-source-name set-use) '-)))
1505 (minusp (eq (combination-fun-source-name set-use) '-))
1506 (+-args (basic-combination-args set-use))
1507 (() (and (proper-list-of-length-p +-args 2 2)
1508 (let ((first (principal-lvar-use
1511 (eq (ref-leaf first) var))))
1513 (step-type (lvar-type (second +-args)))
1514 (set-type (lvar-type (set-value set))))
1515 (when (and (numeric-type-p initial-type)
1516 (numeric-type-p step-type)
1517 (or (numeric-type-equal initial-type step-type)
1518 ;; Detect cases like (LOOP FOR 1.0 to 5.0 ...), where
1519 ;; the initial and the step are of different types,
1520 ;; and the step is less contagious.
1521 (numeric-type-equal initial-type
1522 (numeric-contagion initial-type
1524 (labels ((leftmost (x y cmp cmp=)
1525 (cond ((eq x nil) nil)
1528 (let ((x1 (first x)))
1530 (let ((y1 (first y)))
1531 (if (funcall cmp x1 y1) x y)))
1533 (if (funcall cmp x1 y) x y)))))
1535 (let ((y1 (first y)))
1536 (if (funcall cmp= x y1) x y)))
1537 (t (if (funcall cmp x y) x y))))
1538 (max* (x y) (leftmost x y #'> #'>=))
1539 (min* (x y) (leftmost x y #'< #'<=)))
1540 (multiple-value-bind (low high)
1541 (let ((step-type-non-negative (csubtypep step-type (specifier-type
1543 (step-type-non-positive (csubtypep step-type (specifier-type
1545 (cond ((or (and step-type-non-negative (not minusp))
1546 (and step-type-non-positive minusp))
1547 (values (numeric-type-low initial-type)
1548 (when (and (numeric-type-p set-type)
1549 (numeric-type-equal set-type initial-type))
1550 (max* (numeric-type-high initial-type)
1551 (numeric-type-high set-type)))))
1552 ((or (and step-type-non-positive (not minusp))
1553 (and step-type-non-negative minusp))
1554 (values (when (and (numeric-type-p set-type)
1555 (numeric-type-equal set-type initial-type))
1556 (min* (numeric-type-low initial-type)
1557 (numeric-type-low set-type)))
1558 (numeric-type-high initial-type)))
1561 (modified-numeric-type initial-type
1564 :enumerable nil))))))
1565 (deftransform + ((x y) * * :result result)
1566 "check for iteration variable reoptimization"
1567 (let ((dest (principal-lvar-end result))
1568 (use (principal-lvar-use x)))
1569 (when (and (ref-p use)
1573 (reoptimize-lvar (set-value dest))))
1574 (give-up-ir1-transform))
1576 ;;; Figure out the type of a LET variable that has sets. We compute
1577 ;;; the union of the INITIAL-TYPE and the types of all the set
1578 ;;; values and to a PROPAGATE-TO-REFS with this type.
1579 (defun propagate-from-sets (var initial-type)
1580 (let ((changes (not (csubtypep (lambda-var-last-initial-type var) initial-type)))
1582 (dolist (set (lambda-var-sets var))
1583 (let ((type (lvar-type (set-value set))))
1585 (when (node-reoptimize set)
1586 (let ((old-type (node-derived-type set)))
1587 (unless (values-subtypep old-type type)
1588 (derive-node-type set (make-single-value-type type))
1590 (setf (node-reoptimize set) nil))))
1592 (setf (lambda-var-last-initial-type var) initial-type)
1593 (let ((res-type (or (maybe-infer-iteration-var-type var initial-type)
1594 (apply #'type-union initial-type types))))
1595 (propagate-to-refs var res-type))))
1598 ;;; If a LET variable, find the initial value's type and do
1599 ;;; PROPAGATE-FROM-SETS. We also derive the VALUE's type as the node's
1601 (defun ir1-optimize-set (node)
1602 (declare (type cset node))
1603 (let ((var (set-var node)))
1604 (when (and (lambda-var-p var) (leaf-refs var))
1605 (let ((home (lambda-var-home var)))
1606 (when (eq (functional-kind home) :let)
1607 (let* ((initial-value (let-var-initial-value var))
1608 (initial-type (lvar-type initial-value)))
1609 (setf (lvar-reoptimize initial-value) nil)
1610 (propagate-from-sets var initial-type))))))
1611 (derive-node-type node (make-single-value-type
1612 (lvar-type (set-value node))))
1613 (setf (node-reoptimize node) nil)
1616 ;;; Return true if the value of REF will always be the same (and is
1617 ;;; thus legal to substitute.)
1618 (defun constant-reference-p (ref)
1619 (declare (type ref ref))
1620 (let ((leaf (ref-leaf ref)))
1622 ((or constant functional) t)
1624 (null (lambda-var-sets leaf)))
1626 (not (eq (defined-fun-inlinep leaf) :notinline)))
1628 (case (global-var-kind leaf)
1630 (let ((name (leaf-source-name leaf)))
1632 (eq (symbol-package (fun-name-block-name name))
1634 (info :function :info name)))))))))
1636 ;;; If we have a non-set LET var with a single use, then (if possible)
1637 ;;; replace the variable reference's LVAR with the arg lvar.
1639 ;;; We change the REF to be a reference to NIL with unused value, and
1640 ;;; let it be flushed as dead code. A side effect of this substitution
1641 ;;; is to delete the variable.
1642 (defun substitute-single-use-lvar (arg var)
1643 (declare (type lvar arg) (type lambda-var var))
1644 (binding* ((ref (first (leaf-refs var)))
1645 (lvar (node-lvar ref) :exit-if-null)
1646 (dest (lvar-dest lvar))
1647 (dest-lvar (when (valued-node-p dest) (node-lvar dest))))
1649 ;; Think about (LET ((A ...)) (IF ... A ...)): two
1650 ;; LVAR-USEs should not be met on one path. Another problem
1651 ;; is with dynamic-extent.
1652 (eq (lvar-uses lvar) ref)
1653 (not (block-delete-p (node-block ref)))
1654 ;; If the destinatation is dynamic extent, don't substitute unless
1655 ;; the source is as well.
1657 (not (lvar-dynamic-extent dest-lvar))
1658 (lvar-dynamic-extent lvar))
1660 ;; we should not change lifetime of unknown values lvars
1662 (and (type-single-value-p (lvar-derived-type arg))
1663 (multiple-value-bind (pdest pprev)
1664 (principal-lvar-end lvar)
1665 (declare (ignore pdest))
1666 (lvar-single-value-p pprev))))
1668 (or (eq (basic-combination-fun dest) lvar)
1669 (and (eq (basic-combination-kind dest) :local)
1670 (type-single-value-p (lvar-derived-type arg)))))
1672 ;; While CRETURN and EXIT nodes may be known-values,
1673 ;; they have their own complications, such as
1674 ;; substitution into CRETURN may create new tail calls.
1677 (aver (lvar-single-value-p lvar))
1679 (eq (node-home-lambda ref)
1680 (lambda-home (lambda-var-home var))))
1681 (let ((ref-type (single-value-type (node-derived-type ref))))
1682 (cond ((csubtypep (single-value-type (lvar-type arg)) ref-type)
1683 (substitute-lvar-uses lvar arg
1684 ;; Really it is (EQ (LVAR-USES LVAR) REF):
1686 (delete-lvar-use ref))
1688 (let* ((value (make-lvar))
1689 (cast (insert-cast-before ref value ref-type
1690 ;; KLUDGE: it should be (TYPE-CHECK 0)
1692 (setf (cast-type-to-check cast) *wild-type*)
1693 (substitute-lvar-uses value arg
1696 (%delete-lvar-use ref)
1697 (add-lvar-use cast lvar)))))
1698 (setf (node-derived-type ref) *wild-type*)
1699 (change-ref-leaf ref (find-constant nil))
1702 (reoptimize-lvar lvar)
1705 ;;; Delete a LET, removing the call and bind nodes, and warning about
1706 ;;; any unreferenced variables. Note that FLUSH-DEAD-CODE will come
1707 ;;; along right away and delete the REF and then the lambda, since we
1708 ;;; flush the FUN lvar.
1709 (defun delete-let (clambda)
1710 (declare (type clambda clambda))
1711 (aver (functional-letlike-p clambda))
1712 (note-unreferenced-vars clambda)
1713 (let ((call (let-combination clambda)))
1714 (flush-dest (basic-combination-fun call))
1716 (unlink-node (lambda-bind clambda))
1717 (setf (lambda-bind clambda) nil))
1718 (setf (functional-kind clambda) :zombie)
1719 (let ((home (lambda-home clambda)))
1720 (setf (lambda-lets home) (delete clambda (lambda-lets home))))
1723 ;;; This function is called when one of the arguments to a LET
1724 ;;; changes. We look at each changed argument. If the corresponding
1725 ;;; variable is set, then we call PROPAGATE-FROM-SETS. Otherwise, we
1726 ;;; consider substituting for the variable, and also propagate
1727 ;;; derived-type information for the arg to all the VAR's refs.
1729 ;;; Substitution is inhibited when the arg leaf's derived type isn't a
1730 ;;; subtype of the argument's leaf type. This prevents type checking
1731 ;;; from being defeated, and also ensures that the best representation
1732 ;;; for the variable can be used.
1734 ;;; Substitution of individual references is inhibited if the
1735 ;;; reference is in a different component from the home. This can only
1736 ;;; happen with closures over top level lambda vars. In such cases,
1737 ;;; the references may have already been compiled, and thus can't be
1738 ;;; retroactively modified.
1740 ;;; If all of the variables are deleted (have no references) when we
1741 ;;; are done, then we delete the LET.
1743 ;;; Note that we are responsible for clearing the LVAR-REOPTIMIZE
1745 (defun propagate-let-args (call fun)
1746 (declare (type combination call) (type clambda fun))
1747 (loop for arg in (combination-args call)
1748 and var in (lambda-vars fun) do
1749 (when (and arg (lvar-reoptimize arg))
1750 (setf (lvar-reoptimize arg) nil)
1752 ((lambda-var-sets var)
1753 (propagate-from-sets var (lvar-type arg)))
1754 ((let ((use (lvar-uses arg)))
1756 (let ((leaf (ref-leaf use)))
1757 (when (and (constant-reference-p use)
1758 (csubtypep (leaf-type leaf)
1759 ;; (NODE-DERIVED-TYPE USE) would
1760 ;; be better -- APD, 2003-05-15
1762 (propagate-to-refs var (lvar-type arg))
1763 (let ((use-component (node-component use)))
1764 (prog1 (substitute-leaf-if
1766 (cond ((eq (node-component ref) use-component)
1769 (aver (lambda-toplevelish-p (lambda-home fun)))
1773 ((and (null (rest (leaf-refs var)))
1774 (not (preserve-single-use-debug-var-p call var))
1775 (substitute-single-use-lvar arg var)))
1777 (propagate-to-refs var (lvar-type arg))))))
1779 (when (every #'not (combination-args call))
1784 ;;; This function is called when one of the args to a non-LET local
1785 ;;; call changes. For each changed argument corresponding to an unset
1786 ;;; variable, we compute the union of the types across all calls and
1787 ;;; propagate this type information to the var's refs.
1789 ;;; If the function has an entry-fun, then we don't do anything: since
1790 ;;; it has a XEP we would not discover anything.
1792 ;;; If the function is an optional-entry-point, we will just make sure
1793 ;;; &REST lists are known to be lists. Doing the regular rigamarole
1794 ;;; can erronously propagate too strict types into refs: see
1795 ;;; BUG-655203-REGRESSION in tests/compiler.pure.lisp.
1797 ;;; We can clear the LVAR-REOPTIMIZE flags for arguments in all calls
1798 ;;; corresponding to changed arguments in CALL, since the only use in
1799 ;;; IR1 optimization of the REOPTIMIZE flag for local call args is
1801 (defun propagate-local-call-args (call fun)
1802 (declare (type combination call) (type clambda fun))
1803 (unless (functional-entry-fun fun)
1804 (if (lambda-optional-dispatch fun)
1805 ;; We can still make sure &REST is known to be a list.
1806 (loop for var in (lambda-vars fun)
1807 do (let ((info (lambda-var-arg-info var)))
1808 (when (and info (eq :rest (arg-info-kind info)))
1809 (propagate-from-sets var (specifier-type 'list)))))
1811 (let* ((vars (lambda-vars fun))
1812 (union (mapcar (lambda (arg var)
1814 (lvar-reoptimize arg)
1815 (null (basic-var-sets var)))
1817 (basic-combination-args call)
1819 (this-ref (lvar-use (basic-combination-fun call))))
1821 (dolist (arg (basic-combination-args call))
1823 (setf (lvar-reoptimize arg) nil)))
1825 (dolist (ref (leaf-refs fun))
1826 (let ((dest (node-dest ref)))
1827 (unless (or (eq ref this-ref) (not dest))
1829 (mapcar (lambda (this-arg old)
1831 (setf (lvar-reoptimize this-arg) nil)
1832 (type-union (lvar-type this-arg) old)))
1833 (basic-combination-args dest)
1836 (loop for var in vars
1838 when type do (propagate-to-refs var type)))))
1842 ;;;; multiple values optimization
1844 ;;; Do stuff to notice a change to a MV combination node. There are
1845 ;;; two main branches here:
1846 ;;; -- If the call is local, then it is already a MV let, or should
1847 ;;; become one. Note that although all :LOCAL MV calls must eventually
1848 ;;; be converted to :MV-LETs, there can be a window when the call
1849 ;;; is local, but has not been LET converted yet. This is because
1850 ;;; the entry-point lambdas may have stray references (in other
1851 ;;; entry points) that have not been deleted yet.
1852 ;;; -- The call is full. This case is somewhat similar to the non-MV
1853 ;;; combination optimization: we propagate return type information and
1854 ;;; notice non-returning calls. We also have an optimization
1855 ;;; which tries to convert MV-CALLs into MV-binds.
1856 (defun ir1-optimize-mv-combination (node)
1857 (ecase (basic-combination-kind node)
1859 (let ((fun-lvar (basic-combination-fun node)))
1860 (when (lvar-reoptimize fun-lvar)
1861 (setf (lvar-reoptimize fun-lvar) nil)
1862 (maybe-let-convert (combination-lambda node))))
1863 (setf (lvar-reoptimize (first (basic-combination-args node))) nil)
1864 (when (eq (functional-kind (combination-lambda node)) :mv-let)
1865 (unless (convert-mv-bind-to-let node)
1866 (ir1-optimize-mv-bind node))))
1868 (let* ((fun (basic-combination-fun node))
1869 (fun-changed (lvar-reoptimize fun))
1870 (args (basic-combination-args node)))
1872 (setf (lvar-reoptimize fun) nil)
1873 (let ((type (lvar-type fun)))
1874 (when (fun-type-p type)
1875 (derive-node-type node (fun-type-returns type))))
1876 (maybe-terminate-block node nil)
1877 (let ((use (lvar-uses fun)))
1878 (when (and (ref-p use) (functional-p (ref-leaf use)))
1879 (convert-call-if-possible use node)
1880 (when (eq (basic-combination-kind node) :local)
1881 (maybe-let-convert (ref-leaf use))))))
1882 (unless (or (eq (basic-combination-kind node) :local)
1883 (eq (lvar-fun-name fun) '%throw))
1884 (ir1-optimize-mv-call node))
1886 (setf (lvar-reoptimize arg) nil))))
1890 ;;; Propagate derived type info from the values lvar to the vars.
1891 (defun ir1-optimize-mv-bind (node)
1892 (declare (type mv-combination node))
1893 (let* ((arg (first (basic-combination-args node)))
1894 (vars (lambda-vars (combination-lambda node)))
1895 (n-vars (length vars))
1896 (types (values-type-in (lvar-derived-type arg)
1898 (loop for var in vars
1900 do (if (basic-var-sets var)
1901 (propagate-from-sets var type)
1902 (propagate-to-refs var type)))
1903 (setf (lvar-reoptimize arg) nil))
1906 ;;; If possible, convert a general MV call to an MV-BIND. We can do
1908 ;;; -- The call has only one argument, and
1909 ;;; -- The function has a known fixed number of arguments, or
1910 ;;; -- The argument yields a known fixed number of values.
1912 ;;; What we do is change the function in the MV-CALL to be a lambda
1913 ;;; that "looks like an MV bind", which allows
1914 ;;; IR1-OPTIMIZE-MV-COMBINATION to notice that this call can be
1915 ;;; converted (the next time around.) This new lambda just calls the
1916 ;;; actual function with the MV-BIND variables as arguments. Note that
1917 ;;; this new MV bind is not let-converted immediately, as there are
1918 ;;; going to be stray references from the entry-point functions until
1919 ;;; they get deleted.
1921 ;;; In order to avoid loss of argument count checking, we only do the
1922 ;;; transformation according to a known number of expected argument if
1923 ;;; safety is unimportant. We can always convert if we know the number
1924 ;;; of actual values, since the normal call that we build will still
1925 ;;; do any appropriate argument count checking.
1927 ;;; We only attempt the transformation if the called function is a
1928 ;;; constant reference. This allows us to just splice the leaf into
1929 ;;; the new function, instead of trying to somehow bind the function
1930 ;;; expression. The leaf must be constant because we are evaluating it
1931 ;;; again in a different place. This also has the effect of squelching
1932 ;;; multiple warnings when there is an argument count error.
1933 (defun ir1-optimize-mv-call (node)
1934 (let ((fun (basic-combination-fun node))
1935 (*compiler-error-context* node)
1936 (ref (lvar-uses (basic-combination-fun node)))
1937 (args (basic-combination-args node)))
1939 (unless (and (ref-p ref) (constant-reference-p ref)
1941 (return-from ir1-optimize-mv-call))
1943 (multiple-value-bind (min max)
1944 (fun-type-nargs (lvar-type fun))
1946 (multiple-value-bind (types nvals)
1947 (values-types (lvar-derived-type (first args)))
1948 (declare (ignore types))
1949 (if (eq nvals :unknown) nil nvals))))
1952 (when (and min (< total-nvals min))
1954 "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
1957 (setf (basic-combination-kind node) :error)
1958 (return-from ir1-optimize-mv-call))
1959 (when (and max (> total-nvals max))
1961 "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
1964 (setf (basic-combination-kind node) :error)
1965 (return-from ir1-optimize-mv-call)))
1967 (let ((count (cond (total-nvals)
1968 ((and (policy node (zerop verify-arg-count))
1973 (with-ir1-environment-from-node node
1974 (let* ((dums (make-gensym-list count))
1976 (leaf (ref-leaf ref))
1977 (fun (ir1-convert-lambda
1978 `(lambda (&optional ,@dums &rest ,ignore)
1979 (declare (ignore ,ignore))
1980 (%funcall ,leaf ,@dums))
1981 :source-name (leaf-%source-name leaf)
1982 :debug-name (leaf-%debug-name leaf))))
1983 (change-ref-leaf ref fun)
1984 (aver (eq (basic-combination-kind node) :full))
1985 (locall-analyze-component *current-component*)
1986 (aver (eq (basic-combination-kind node) :local)))))))))
1990 ;;; (multiple-value-bind
1999 ;;; What we actually do is convert the VALUES combination into a
2000 ;;; normal LET combination calling the original :MV-LET lambda. If
2001 ;;; there are extra args to VALUES, discard the corresponding
2002 ;;; lvars. If there are insufficient args, insert references to NIL.
2003 (defun convert-mv-bind-to-let (call)
2004 (declare (type mv-combination call))
2005 (let* ((arg (first (basic-combination-args call)))
2006 (use (lvar-uses arg)))
2007 (when (and (combination-p use)
2008 (eq (lvar-fun-name (combination-fun use))
2010 (let* ((fun (combination-lambda call))
2011 (vars (lambda-vars fun))
2012 (vals (combination-args use))
2013 (nvars (length vars))
2014 (nvals (length vals)))
2015 (cond ((> nvals nvars)
2016 (mapc #'flush-dest (subseq vals nvars))
2017 (setq vals (subseq vals 0 nvars)))
2019 (with-ir1-environment-from-node use
2020 (let ((node-prev (node-prev use)))
2021 (setf (node-prev use) nil)
2022 (setf (ctran-next node-prev) nil)
2023 (collect ((res vals))
2024 (loop for count below (- nvars nvals)
2025 for prev = node-prev then ctran
2026 for ctran = (make-ctran)
2027 and lvar = (make-lvar use)
2028 do (reference-constant prev ctran lvar nil)
2030 finally (link-node-to-previous-ctran
2032 (setq vals (res)))))))
2033 (setf (combination-args use) vals)
2034 (flush-dest (combination-fun use))
2035 (let ((fun-lvar (basic-combination-fun call)))
2036 (setf (lvar-dest fun-lvar) use)
2037 (setf (combination-fun use) fun-lvar)
2038 (flush-lvar-externally-checkable-type fun-lvar))
2039 (setf (combination-kind use) :local)
2040 (setf (functional-kind fun) :let)
2041 (flush-dest (first (basic-combination-args call)))
2044 (reoptimize-lvar (first vals)))
2045 ;; Propagate derived types from the VALUES call to its args:
2046 ;; transforms can leave the VALUES call with a better type
2047 ;; than its args have, so make sure not to throw that away.
2048 (let ((types (values-type-types (node-derived-type use))))
2051 (let ((type (pop types)))
2052 (assert-lvar-type val type '((type-check . 0)))))))
2053 ;; Propagate declared types of MV-BIND variables.
2054 (propagate-to-args use fun)
2055 (reoptimize-call use))
2059 ;;; (values-list (list x y z))
2064 ;;; In implementation, this is somewhat similar to
2065 ;;; CONVERT-MV-BIND-TO-LET. We grab the args of LIST and make them
2066 ;;; args of the VALUES-LIST call, flushing the old argument lvar
2067 ;;; (allowing the LIST to be flushed.)
2069 ;;; FIXME: Thus we lose possible type assertions on (LIST ...).
2070 (defoptimizer (values-list optimizer) ((list) node)
2071 (let ((use (lvar-uses list)))
2072 (when (and (combination-p use)
2073 (eq (lvar-fun-name (combination-fun use))
2076 ;; FIXME: VALUES might not satisfy an assertion on NODE-LVAR.
2077 (change-ref-leaf (lvar-uses (combination-fun node))
2078 (find-free-fun 'values "in a strange place"))
2079 (setf (combination-kind node) :full)
2080 (let ((args (combination-args use)))
2082 (setf (lvar-dest arg) node)
2083 (flush-lvar-externally-checkable-type arg))
2084 (setf (combination-args use) nil)
2086 (flush-combination use)
2087 (setf (combination-args node) args))
2090 ;;; If VALUES appears in a non-MV context, then effectively convert it
2091 ;;; to a PROG1. This allows the computation of the additional values
2092 ;;; to become dead code.
2093 (deftransform values ((&rest vals) * * :node node)
2094 (unless (lvar-single-value-p (node-lvar node))
2095 (give-up-ir1-transform))
2096 (setf (node-derived-type node)
2097 (make-short-values-type (list (single-value-type
2098 (node-derived-type node)))))
2099 (principal-lvar-single-valuify (node-lvar node))
2101 (let ((dummies (make-gensym-list (length (cdr vals)))))
2102 `(lambda (val ,@dummies)
2103 (declare (ignore ,@dummies))
2109 (defun delete-cast (cast)
2110 (declare (type cast cast))
2111 (let ((value (cast-value cast))
2112 (lvar (node-lvar cast)))
2113 (delete-filter cast lvar value)
2115 (reoptimize-lvar lvar)
2116 (when (lvar-single-value-p lvar)
2117 (note-single-valuified-lvar lvar)))
2120 (defun ir1-optimize-cast (cast &optional do-not-optimize)
2121 (declare (type cast cast))
2122 (let ((value (cast-value cast))
2123 (atype (cast-asserted-type cast)))
2124 (when (not do-not-optimize)
2125 (let ((lvar (node-lvar cast)))
2126 (when (values-subtypep (lvar-derived-type value)
2127 (cast-asserted-type cast))
2129 (return-from ir1-optimize-cast t))
2131 (when (and (listp (lvar-uses value))
2133 ;; Pathwise removing of CAST
2134 (let ((ctran (node-next cast))
2135 (dest (lvar-dest lvar))
2138 (do-uses (use value)
2139 (when (and (values-subtypep (node-derived-type use) atype)
2140 (immediately-used-p value use))
2142 (when ctran (ensure-block-start ctran))
2143 (setq next-block (first (block-succ (node-block cast))))
2144 (ensure-block-start (node-prev cast))
2145 (reoptimize-lvar lvar)
2146 (setf (lvar-%derived-type value) nil))
2147 (%delete-lvar-use use)
2148 (add-lvar-use use lvar)
2149 (unlink-blocks (node-block use) (node-block cast))
2150 (link-blocks (node-block use) next-block)
2151 (when (and (return-p dest)
2152 (basic-combination-p use)
2153 (eq (basic-combination-kind use) :local))
2155 (dolist (use (merges))
2156 (merge-tail-sets use)))))))
2158 (let* ((value-type (lvar-derived-type value))
2159 (int (values-type-intersection value-type atype)))
2160 (derive-node-type cast int)
2161 (when (eq int *empty-type*)
2162 (unless (eq value-type *empty-type*)
2164 ;; FIXME: Do it in one step.
2165 (let ((context (cons (node-source-form cast)
2166 (lvar-all-sources (cast-value cast)))))
2169 (if (cast-single-value-p cast)
2171 `(multiple-value-call #'list 'dummy)))
2174 ;; FIXME: Derived type.
2175 `(%compile-time-type-error 'dummy
2176 ',(type-specifier atype)
2177 ',(type-specifier value-type)
2179 ;; KLUDGE: FILTER-LVAR does not work for non-returning
2180 ;; functions, so we declare the return type of
2181 ;; %COMPILE-TIME-TYPE-ERROR to be * and derive the real type
2183 (setq value (cast-value cast))
2184 (derive-node-type (lvar-uses value) *empty-type*)
2185 (maybe-terminate-block (lvar-uses value) nil)
2186 ;; FIXME: Is it necessary?
2187 (aver (null (block-pred (node-block cast))))
2188 (delete-block-lazily (node-block cast))
2189 (return-from ir1-optimize-cast)))
2190 (when (eq (node-derived-type cast) *empty-type*)
2191 (maybe-terminate-block cast nil))
2193 (when (and (cast-%type-check cast)
2194 (values-subtypep value-type
2195 (cast-type-to-check cast)))
2196 (setf (cast-%type-check cast) nil))))
2198 (unless do-not-optimize
2199 (setf (node-reoptimize cast) nil)))
2201 (deftransform make-symbol ((string) (simple-string))
2202 `(%make-symbol string))