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 and singleton numeric types
29 (values (type-singleton-p (lvar-type thing
))))))
31 ;;; Return the constant value for an LVAR whose only use is a constant
33 (declaim (ftype (function (lvar) t
) lvar-value
))
34 (defun lvar-value (lvar)
35 (let ((use (principal-lvar-use lvar
))
36 (type (lvar-type lvar
))
39 (constant-p (setf leaf
(ref-leaf use
))))
41 (multiple-value-bind (constantp value
) (type-singleton-p type
)
43 (error "~S used on non-constant LVAR ~S" 'lvar-value lvar
))
46 ;;;; interface for obtaining results of type inference
48 ;;; Our best guess for the type of this lvar's value. Note that this
49 ;;; may be VALUES or FUNCTION type, which cannot be passed as an
50 ;;; argument to the normal type operations. See LVAR-TYPE.
52 ;;; The result value is cached in the LVAR-%DERIVED-TYPE slot. If the
53 ;;; slot is true, just return that value, otherwise recompute and
54 ;;; stash the value there.
55 (eval-when (:compile-toplevel
:execute
)
56 (#+sb-xc-host cl
:defmacro
57 #-sb-xc-host sb
!xc
:defmacro
58 lvar-type-using
(lvar accessor
)
59 `(let ((uses (lvar-uses ,lvar
)))
60 (cond ((null uses
) *empty-type
*)
62 (do ((res (,accessor
(first uses
))
63 (values-type-union (,accessor
(first current
))
65 (current (rest uses
) (rest current
)))
66 ((or (null current
) (eq res
*wild-type
*))
71 #!-sb-fluid
(declaim (inline lvar-derived-type
))
72 (defun lvar-derived-type (lvar)
73 (declare (type lvar lvar
))
74 (or (lvar-%derived-type lvar
)
75 (setf (lvar-%derived-type lvar
)
76 (%lvar-derived-type lvar
))))
77 (defun %lvar-derived-type
(lvar)
78 (lvar-type-using lvar node-derived-type
))
80 ;;; Return the derived type for LVAR's first value. This is guaranteed
81 ;;; not to be a VALUES or FUNCTION type.
82 (declaim (ftype (sfunction (lvar) ctype
) lvar-type
))
83 (defun lvar-type (lvar)
84 (single-value-type (lvar-derived-type lvar
)))
86 ;;; LVAR-CONSERVATIVE-TYPE
88 ;;; Certain types refer to the contents of an object, which can
89 ;;; change without type derivation noticing: CONS types and ARRAY
90 ;;; types suffer from this:
92 ;;; (let ((x (the (cons fixnum fixnum) (cons a b))))
94 ;;; (+ (car x) (cdr x)))
96 ;;; Python doesn't realize that the SETF CAR can change the type of X -- so we
97 ;;; cannot use LVAR-TYPE which gets the derived results. Worse, still, instead
98 ;;; of (SETF CAR) we might have a call to a user-defined function FOO which
99 ;;; does the same -- so there is no way to use the derived information in
102 ;;; So, the conservative option is to use the derived type if the leaf has
103 ;;; only a single ref -- in which case there cannot be a prior call that
104 ;;; mutates it. Otherwise we use the declared type or punt to the most general
105 ;;; type we know to be correct for sure.
106 (defun lvar-conservative-type (lvar)
107 (let ((derived-type (lvar-type lvar
))
108 (t-type *universal-type
*))
109 ;; Recompute using NODE-CONSERVATIVE-TYPE instead of derived type if
110 ;; necessary -- picking off some easy cases up front.
111 (cond ((or (eq derived-type t-type
)
112 ;; Can't use CSUBTYPEP!
113 (type= derived-type
(specifier-type 'list
))
114 (type= derived-type
(specifier-type 'null
)))
116 ((and (cons-type-p derived-type
)
117 (eq t-type
(cons-type-car-type derived-type
))
118 (eq t-type
(cons-type-cdr-type derived-type
)))
120 ((and (array-type-p derived-type
)
121 (or (not (array-type-complexp derived-type
))
122 (let ((dimensions (array-type-dimensions derived-type
)))
123 (or (eq '* dimensions
)
124 (every (lambda (dim) (eq '* dim
)) dimensions
)))))
126 ((type-needs-conservation-p derived-type
)
127 (single-value-type (lvar-type-using lvar node-conservative-type
)))
131 (defun node-conservative-type (node)
132 (let* ((derived-values-type (node-derived-type node
))
133 (derived-type (single-value-type derived-values-type
)))
135 (let ((leaf (ref-leaf node
)))
136 (if (and (basic-var-p leaf
)
137 (cdr (leaf-refs leaf
)))
139 (if (eq :declared
(leaf-where-from leaf
))
141 (conservative-type derived-type
)))
142 derived-values-type
))
143 derived-values-type
)))
145 (defun conservative-type (type)
146 (cond ((or (eq type
*universal-type
*)
147 (eq type
(specifier-type 'list
))
148 (eq type
(specifier-type 'null
)))
151 (specifier-type 'cons
))
153 (if (array-type-complexp type
)
155 ;; ADJUST-ARRAY may change dimensions, but rank stays same.
156 (let ((old (array-type-dimensions type
)))
159 (mapcar (constantly '*) old
)))
160 ;; Complexity cannot change.
161 :complexp
(array-type-complexp type
)
162 ;; Element type cannot change.
163 :element-type
(array-type-element-type type
)
164 :specialized-element-type
(array-type-specialized-element-type type
))
165 ;; Simple arrays cannot change at all.
168 ;; Conservative union type is an union of conservative types.
169 (let ((res *empty-type
*))
170 (dolist (part (union-type-types type
) res
)
171 (setf res
(type-union res
(conservative-type part
))))))
175 ;; If the type contains some CONS types, the conservative type contains all
177 (when (types-equal-or-intersect type
(specifier-type 'cons
))
178 (setf type
(type-union type
(specifier-type 'cons
))))
179 ;; Similarly for non-simple arrays -- it should be possible to preserve
180 ;; more information here, but really...
181 (let ((non-simple-arrays (specifier-type '(and array
(not simple-array
)))))
182 (when (types-equal-or-intersect type non-simple-arrays
)
183 (setf type
(type-union type non-simple-arrays
))))
186 (defun type-needs-conservation-p (type)
187 (cond ((eq type
*universal-type
*)
188 ;; Excluding T is necessary, because we do want type derivation to
189 ;; be able to narrow it down in case someone (most like a macro-expansion...)
190 ;; actually declares something as having type T.
192 ((or (cons-type-p type
) (and (array-type-p type
) (array-type-complexp type
)))
193 ;; Covered by the next case as well, but this is a quick test.
195 ((types-equal-or-intersect type
(specifier-type '(or cons
(and array
(not simple-array
)))))
198 ;;; If LVAR is an argument of a function, return a type which the
199 ;;; function checks LVAR for.
200 #!-sb-fluid
(declaim (inline lvar-externally-checkable-type
))
201 (defun lvar-externally-checkable-type (lvar)
202 (or (lvar-%externally-checkable-type lvar
)
203 (%lvar-%externally-checkable-type lvar
)))
204 (defun %lvar-%externally-checkable-type
(lvar)
205 (declare (type lvar lvar
))
206 (let ((dest (lvar-dest lvar
)))
207 (if (not (and dest
(combination-p dest
)))
208 ;; TODO: MV-COMBINATION
209 (setf (lvar-%externally-checkable-type lvar
) *wild-type
*)
210 (let* ((fun (combination-fun dest
))
211 (args (combination-args dest
))
212 (fun-type (lvar-type fun
)))
213 (setf (lvar-%externally-checkable-type fun
) *wild-type
*)
214 (if (or (not (call-full-like-p dest
))
215 (not (fun-type-p fun-type
))
216 ;; FUN-TYPE might be (AND FUNCTION (SATISFIES ...)).
217 (fun-type-wild-args fun-type
))
220 (setf (lvar-%externally-checkable-type arg
)
222 (map-combination-args-and-types
224 (setf (lvar-%externally-checkable-type arg
)
225 (acond ((lvar-%externally-checkable-type arg
)
226 (values-type-intersection
227 it
(coerce-to-values type
)))
228 (t (coerce-to-values type
)))))
230 (or (lvar-%externally-checkable-type lvar
) *wild-type
*))
231 #!-sb-fluid
(declaim (inline flush-lvar-externally-checkable-type
))
232 (defun flush-lvar-externally-checkable-type (lvar)
233 (declare (type lvar lvar
))
234 (setf (lvar-%externally-checkable-type lvar
) nil
))
236 ;;;; interface routines used by optimizers
238 (declaim (inline reoptimize-component
))
239 (defun reoptimize-component (component kind
)
240 (declare (type component component
)
241 (type (member nil
:maybe t
) kind
))
243 (unless (eq (component-reoptimize component
) t
)
244 (setf (component-reoptimize component
) kind
)))
246 ;;; This function is called by optimizers to indicate that something
247 ;;; interesting has happened to the value of LVAR. Optimizers must
248 ;;; make sure that they don't call for reoptimization when nothing has
249 ;;; happened, since optimization will fail to terminate.
251 ;;; We clear any cached type for the lvar and set the reoptimize flags
252 ;;; on everything in sight.
253 (defun reoptimize-lvar (lvar)
254 (declare (type (or lvar null
) lvar
))
256 (setf (lvar-%derived-type lvar
) nil
)
257 (let ((dest (lvar-dest lvar
)))
259 (setf (lvar-reoptimize lvar
) t
)
260 (setf (node-reoptimize dest
) t
)
261 (binding* (;; Since this may be called during IR1 conversion,
262 ;; PREV may be missing.
263 (prev (node-prev dest
) :exit-if-null
)
264 (block (ctran-block prev
))
265 (component (block-component block
)))
266 (when (typep dest
'cif
)
267 (setf (block-test-modified block
) t
))
268 (setf (block-reoptimize block
) t
)
269 (reoptimize-component component
:maybe
))))
271 (setf (block-type-check (node-block node
)) t
)))
274 (defun reoptimize-lvar-uses (lvar)
275 (declare (type lvar lvar
))
277 (setf (node-reoptimize use
) t
)
278 (setf (block-reoptimize (node-block use
)) t
)
279 (reoptimize-component (node-component use
) :maybe
)))
281 ;;; Annotate NODE to indicate that its result has been proven to be
282 ;;; TYPEP to RTYPE. After IR1 conversion has happened, this is the
283 ;;; only correct way to supply information discovered about a node's
284 ;;; type. If you screw with the NODE-DERIVED-TYPE directly, then
285 ;;; information may be lost and reoptimization may not happen.
287 ;;; What we do is intersect RTYPE with NODE's DERIVED-TYPE. If the
288 ;;; intersection is different from the old type, then we do a
289 ;;; REOPTIMIZE-LVAR on the NODE-LVAR.
290 (defun derive-node-type (node rtype
&key from-scratch
)
291 (declare (type valued-node node
) (type ctype rtype
))
292 (let* ((initial-type (node-derived-type node
))
293 (node-type (if from-scratch
296 (unless (eq initial-type rtype
)
297 (let ((int (values-type-intersection node-type rtype
))
298 (lvar (node-lvar node
)))
299 (when (type/= initial-type int
)
300 (when (and *check-consistency
*
301 (eq int
*empty-type
*)
302 (not (eq rtype
*empty-type
*)))
303 (aver (not from-scratch
))
304 (let ((*compiler-error-context
* node
))
306 "New inferred type ~S conflicts with old type:~
307 ~% ~S~%*** possible internal error? Please report this."
308 (type-specifier rtype
) (type-specifier node-type
))))
309 (setf (node-derived-type node
) int
)
310 ;; If the new type consists of only one object, replace the
311 ;; node with a constant reference.
312 (when (and (ref-p node
)
313 (lambda-var-p (ref-leaf node
)))
314 (let ((type (single-value-type int
)))
315 (when (and (member-type-p type
)
316 (eql 1 (member-type-size type
)))
317 (change-ref-leaf node
(find-constant
318 (first (member-type-members type
)))))))
319 (reoptimize-lvar lvar
)))))
322 ;;; This is similar to DERIVE-NODE-TYPE, but asserts that it is an
323 ;;; error for LVAR's value not to be TYPEP to TYPE. We implement it
324 ;;; splitting off DEST a new CAST node; old LVAR will deliver values
325 ;;; to CAST. If we improve the assertion, we set TYPE-CHECK and
326 ;;; TYPE-ASSERTED to guarantee that the new assertion will be checked.
327 (defun assert-lvar-type (lvar type policy
)
328 (declare (type lvar lvar
) (type ctype type
))
329 (unless (values-subtypep (lvar-derived-type lvar
) type
)
330 (let ((internal-lvar (make-lvar))
331 (dest (lvar-dest lvar
)))
332 (substitute-lvar internal-lvar lvar
)
333 (let ((cast (insert-cast-before dest lvar type policy
)))
334 (use-lvar cast internal-lvar
)
340 ;;; Do one forward pass over COMPONENT, deleting unreachable blocks
341 ;;; and doing IR1 optimizations. We can ignore all blocks that don't
342 ;;; have the REOPTIMIZE flag set. If COMPONENT-REOPTIMIZE is true when
343 ;;; we are done, then another iteration would be beneficial.
344 (defun ir1-optimize (component fastp
)
345 (declare (type component component
))
346 (setf (component-reoptimize component
) nil
)
347 (loop with block
= (block-next (component-head component
))
348 with tail
= (component-tail component
)
349 for last-block
= block
350 until
(eq block tail
)
352 ;; We delete blocks when there is either no predecessor or the
353 ;; block is in a lambda that has been deleted. These blocks
354 ;; would eventually be deleted by DFO recomputation, but doing
355 ;; it here immediately makes the effect available to IR1
357 ((or (block-delete-p block
)
358 (null (block-pred block
)))
359 (delete-block-lazily block
)
360 (setq block
(clean-component component block
)))
361 ((eq (functional-kind (block-home-lambda block
)) :deleted
)
362 ;; Preserve the BLOCK-SUCC invariant that almost every block has
363 ;; one successor (and a block with DELETE-P set is an acceptable
365 (mark-for-deletion block
)
366 (setq block
(clean-component component block
)))
369 (let ((succ (block-succ block
)))
370 (unless (singleton-p succ
)
373 (let ((last (block-last block
)))
376 (flush-dest (if-test last
))
377 (when (unlink-node last
)
380 (when (maybe-delete-exit last
)
383 (unless (join-successor-if-possible block
)
386 (when (and (not fastp
) (block-reoptimize block
) (block-component block
))
387 (aver (not (block-delete-p block
)))
388 (ir1-optimize-block block
))
390 (cond ((and (block-delete-p block
) (block-component block
))
391 (setq block
(clean-component component block
)))
392 ((and (block-flush-p block
) (block-component block
))
393 (flush-dead-code block
)))))
394 do
(when (eq block last-block
)
395 (setq block
(block-next block
))))
399 ;;; Loop over the nodes in BLOCK, acting on (and clearing) REOPTIMIZE
402 ;;; Note that although they are cleared here, REOPTIMIZE flags might
403 ;;; still be set upon return from this function, meaning that further
404 ;;; optimization is wanted (as a consequence of optimizations we did).
405 (defun ir1-optimize-block (block)
406 (declare (type cblock block
))
407 ;; We clear the node and block REOPTIMIZE flags before doing the
408 ;; optimization, not after. This ensures that the node or block will
409 ;; be reoptimized if necessary.
410 (setf (block-reoptimize block
) nil
)
411 (do-nodes (node nil block
:restart-p t
)
412 (when (node-reoptimize node
)
413 ;; As above, we clear the node REOPTIMIZE flag before optimizing.
414 (setf (node-reoptimize node
) nil
)
418 ;; With a COMBINATION, we call PROPAGATE-FUN-CHANGE whenever
419 ;; the function changes, and call IR1-OPTIMIZE-COMBINATION if
420 ;; any argument changes.
421 (ir1-optimize-combination node
))
423 (ir1-optimize-if node
))
425 ;; KLUDGE: We leave the NODE-OPTIMIZE flag set going into
426 ;; IR1-OPTIMIZE-RETURN, since IR1-OPTIMIZE-RETURN wants to
427 ;; clear the flag itself. -- WHN 2002-02-02, quoting original
429 (setf (node-reoptimize node
) t
)
430 (ir1-optimize-return node
))
432 (ir1-optimize-mv-combination node
))
434 ;; With an EXIT, we derive the node's type from the VALUE's
436 (let ((value (exit-value node
)))
438 (derive-node-type node
(lvar-derived-type value
)))))
440 ;; PROPAGATE-FROM-SETS can do a better job if NODE-REOPTIMIZE
441 ;; is accurate till the node actually has been reoptimized.
442 (setf (node-reoptimize node
) t
)
443 (ir1-optimize-set node
))
445 (ir1-optimize-cast node
)))))
449 ;;; Try to join with a successor block. If we succeed, we return true,
451 (defun join-successor-if-possible (block)
452 (declare (type cblock block
))
453 (let ((next (first (block-succ block
))))
454 (when (block-start next
) ; NEXT is not an END-OF-COMPONENT marker
455 (cond ( ;; We cannot combine with a successor block if:
457 ;; the successor has more than one predecessor;
458 (rest (block-pred next
))
459 ;; the successor is the current block (infinite loop);
461 ;; the next block has a different cleanup, and thus
462 ;; we may want to insert cleanup code between the
463 ;; two blocks at some point;
464 (not (eq (block-end-cleanup block
)
465 (block-start-cleanup next
)))
466 ;; the next block has a different home lambda, and
467 ;; thus the control transfer is a non-local exit.
468 (not (eq (block-home-lambda block
)
469 (block-home-lambda next
)))
470 ;; Stack analysis phase wants ENTRY to start a block...
471 (entry-p (block-start-node next
))
472 (let ((last (block-last block
)))
473 (and (valued-node-p last
)
474 (awhen (node-lvar last
)
476 ;; ... and a DX-allocator to end a block.
477 (lvar-dynamic-extent it
)
478 ;; FIXME: This is a partial workaround for bug 303.
479 (consp (lvar-uses it
)))))))
482 (join-blocks block next
)
485 ;;; Join together two blocks. The code in BLOCK2 is moved into BLOCK1
486 ;;; and BLOCK2 is deleted from the DFO. We combine the optimize flags
487 ;;; for the two blocks so that any indicated optimization gets done.
488 (defun join-blocks (block1 block2
)
489 (declare (type cblock block1 block2
))
490 (let* ((last1 (block-last block1
))
491 (last2 (block-last block2
))
492 (succ (block-succ block2
))
493 (start2 (block-start block2
)))
494 (do ((ctran start2
(node-next (ctran-next ctran
))))
496 (setf (ctran-block ctran
) block1
))
498 (unlink-blocks block1 block2
)
500 (unlink-blocks block2 block
)
501 (link-blocks block1 block
))
503 (setf (ctran-kind start2
) :inside-block
)
504 (setf (node-next last1
) start2
)
505 (setf (ctran-use start2
) last1
)
506 (setf (block-last block1
) last2
))
508 (setf (block-flags block1
)
509 (attributes-union (block-flags block1
)
511 (block-attributes type-asserted test-modified
)))
513 (let ((next (block-next block2
))
514 (prev (block-prev block2
)))
515 (setf (block-next prev
) next
)
516 (setf (block-prev next
) prev
))
520 ;;; Delete any nodes in BLOCK whose value is unused and which have no
521 ;;; side effects. We can delete sets of lexical variables when the set
522 ;;; variable has no references.
523 (defun flush-dead-code (block &aux victim
)
524 (declare (type cblock block
))
525 (setf (block-flush-p block
) nil
)
526 (do-nodes-backwards (node lvar block
:restart-p t
)
534 (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
))
545 (flush-dest (first (basic-combination-args node
)))
548 (let ((value (exit-value node
)))
552 (setf (exit-value node
) nil
))))
554 (let ((var (set-var node
)))
555 (when (and (lambda-var-p var
)
556 (null (leaf-refs var
)))
558 (flush-dest (set-value node
))
559 (setf (basic-var-sets var
)
560 (delq node
(basic-var-sets var
)))
561 (unlink-node node
))))
563 (unless (cast-type-check node
)
565 (flush-dest (cast-value node
))
566 (unlink-node node
))))))
570 ;;;; local call return type propagation
572 ;;; This function is called on RETURN nodes that have their REOPTIMIZE
573 ;;; flag set. It iterates over the uses of the RESULT, looking for
574 ;;; interesting stuff to update the TAIL-SET. If a use isn't a local
575 ;;; call, then we union its type together with the types of other such
576 ;;; uses. We assign to the RETURN-RESULT-TYPE the intersection of this
577 ;;; type with the RESULT's asserted type. We can make this
578 ;;; intersection now (potentially before type checking) because this
579 ;;; assertion on the result will eventually be checked (if
582 ;;; We call MAYBE-CONVERT-TAIL-LOCAL-CALL on each local non-MV
583 ;;; combination, which may change the successor of the call to be the
584 ;;; called function, and if so, checks if the call can become an
585 ;;; assignment. If we convert to an assignment, we abort, since the
586 ;;; RETURN has been deleted.
587 (defun find-result-type (node)
588 (declare (type creturn node
))
589 (let ((result (return-result node
)))
590 (collect ((use-union *empty-type
* values-type-union
))
591 (do-uses (use result
)
592 (let ((use-home (node-home-lambda use
)))
593 (cond ((or (eq (functional-kind use-home
) :deleted
)
594 (block-delete-p (node-block use
))))
595 ((and (basic-combination-p use
)
596 (eq (basic-combination-kind use
) :local
))
597 (aver (eq (lambda-tail-set use-home
)
598 (lambda-tail-set (combination-lambda use
))))
599 (when (combination-p use
)
600 (when (nth-value 1 (maybe-convert-tail-local-call use
))
601 (return-from find-result-type t
))))
603 (use-union (node-derived-type use
))))))
605 ;; (values-type-intersection
606 ;; (continuation-asserted-type result) ; FIXME -- APD, 2002-01-26
610 (setf (return-result-type node
) int
))))
613 ;;; Do stuff to realize that something has changed about the value
614 ;;; delivered to a return node. Since we consider the return values of
615 ;;; all functions in the tail set to be equivalent, this amounts to
616 ;;; bringing the entire tail set up to date. We iterate over the
617 ;;; returns for all the functions in the tail set, reanalyzing them
618 ;;; all (not treating NODE specially.)
620 ;;; When we are done, we check whether the new type is different from
621 ;;; the old TAIL-SET-TYPE. If so, we set the type and also reoptimize
622 ;;; all the lvars for references to functions in the tail set. This
623 ;;; will cause IR1-OPTIMIZE-COMBINATION to derive the new type as the
624 ;;; results of the calls.
625 (defun ir1-optimize-return (node)
626 (declare (type creturn node
))
629 (let* ((tails (lambda-tail-set (return-lambda node
)))
630 (funs (tail-set-funs tails
)))
631 (collect ((res *empty-type
* values-type-union
))
633 (let ((return (lambda-return fun
)))
635 (when (node-reoptimize return
)
636 (setf (node-reoptimize return
) nil
)
637 (when (find-result-type return
)
639 (res (return-result-type return
)))))
641 (when (type/= (res) (tail-set-type tails
))
642 (setf (tail-set-type tails
) (res))
643 (dolist (fun (tail-set-funs tails
))
644 (dolist (ref (leaf-refs fun
))
645 (reoptimize-lvar (node-lvar ref
))))))))
651 ;;; Utility: return T if both argument cblocks are equivalent. For now,
652 ;;; detect only blocks that read the same leaf into the same lvar, and
653 ;;; continue to the same block.
654 (defun cblocks-equivalent-p (x y
)
655 (declare (type cblock x y
))
656 (and (ref-p (block-start-node x
))
657 (eq (block-last x
) (block-start-node x
))
659 (ref-p (block-start-node y
))
660 (eq (block-last y
) (block-start-node y
))
662 (equal (block-succ x
) (block-succ y
))
663 (eql (ref-lvar (block-start-node x
)) (ref-lvar (block-start-node y
)))
664 (eql (ref-leaf (block-start-node x
)) (ref-leaf (block-start-node y
)))))
666 ;;; Check whether the predicate is known to be true or false,
667 ;;; deleting the IF node in favor of the appropriate branch when this
669 ;;; Similarly, when both branches are equivalent, branch directly to either
671 ;;; Also, if the test has multiple uses, replicate the node when possible...
672 ;;; in fact, splice in direct jumps to the right branch if possible.
673 (defun ir1-optimize-if (node)
674 (declare (type cif node
))
675 (let ((test (if-test node
))
676 (block (node-block node
)))
677 (let* ((type (lvar-type test
))
678 (consequent (if-consequent node
))
679 (alternative (if-alternative node
))
681 (cond ((constant-lvar-p test
)
682 (if (lvar-value test
) alternative consequent
))
683 ((not (types-equal-or-intersect type
(specifier-type 'null
)))
685 ((type= type
(specifier-type 'null
))
687 ((or (eq consequent alternative
) ; Can this happen?
688 (cblocks-equivalent-p alternative consequent
))
691 (kill-if-branch-1 node test block victim
)
692 (return-from ir1-optimize-if
(values))))
693 (tension-if-if-1 node test block
)
694 (duplicate-if-if-1 node test block
)
697 ;; When we know that we only have a single successor, kill the victim
698 ;; ... unless the victim and the remaining successor are the same.
699 (defun kill-if-branch-1 (node test block victim
)
700 (declare (type cif node
))
702 (when (rest (block-succ block
))
703 (unlink-blocks block victim
))
704 (setf (component-reanalyze (node-component node
)) t
)
707 ;; When if/if conversion would leave (if ... (if nil ...)) or
708 ;; (if ... (if not-nil ...)), splice the correct successor right
710 (defun tension-if-if-1 (node test block
)
711 (when (and (eq (block-start-node block
) node
)
712 (listp (lvar-uses test
)))
714 (when (immediately-used-p test use
)
715 (let* ((type (single-value-type (node-derived-type use
)))
716 (target (if (type= type
(specifier-type 'null
))
717 (if-alternative node
)
718 (multiple-value-bind (typep surep
)
720 (and (not typep
) surep
721 (if-consequent node
))))))
723 (let ((pred (node-block use
)))
724 (cond ((listp (lvar-uses test
))
725 (change-block-successor pred block target
)
726 (delete-lvar-use use
))
728 ;; only one use left. Just kill the now-useless
729 ;; branch to avoid spurious code deletion notes.
730 (aver (rest (block-succ block
)))
733 (if (eql target
(if-alternative node
))
735 (if-alternative node
)))
736 (return-from tension-if-if-1
))))))))))
738 ;; Finally, duplicate EQ-nil tests
739 (defun duplicate-if-if-1 (node test block
)
740 (when (and (eq (block-start-node block
) node
)
741 (listp (lvar-uses test
)))
743 (when (immediately-used-p test use
)
744 (convert-if-if use node
)
745 ;; leave the last use as is, instead of replacing
746 ;; the (singly-referenced) CIF node with a duplicate.
747 (when (not (listp (lvar-uses test
))) (return))))))
749 ;;; Create a new copy of an IF node that tests the value of the node
750 ;;; USE. The test must have >1 use, and must be immediately used by
751 ;;; USE. NODE must be the only node in its block (implying that
752 ;;; block-start = if-test).
754 ;;; This optimization has an effect semantically similar to the
755 ;;; source-to-source transformation:
756 ;;; (IF (IF A B C) D E) ==>
757 ;;; (IF A (IF B D E) (IF C D E))
759 ;;; We clobber the NODE-SOURCE-PATH of both the original and the new
760 ;;; node so that dead code deletion notes will definitely not consider
761 ;;; either node to be part of the original source. One node might
762 ;;; become unreachable, resulting in a spurious note.
763 (defun convert-if-if (use node
)
764 (declare (type node use
) (type cif node
))
765 (with-ir1-environment-from-node node
766 (let* ((block (node-block node
))
767 (test (if-test node
))
768 (cblock (if-consequent node
))
769 (ablock (if-alternative node
))
770 (use-block (node-block use
))
771 (new-ctran (make-ctran))
772 (new-lvar (make-lvar))
773 (new-node (make-if :test new-lvar
775 :alternative ablock
))
776 (new-block (ctran-starts-block new-ctran
)))
777 (link-node-to-previous-ctran new-node new-ctran
)
778 (setf (lvar-dest new-lvar
) new-node
)
779 (setf (block-last new-block
) new-node
)
781 (unlink-blocks use-block block
)
782 (%delete-lvar-use use
)
783 (add-lvar-use use new-lvar
)
784 (link-blocks use-block new-block
)
786 (link-blocks new-block cblock
)
787 (link-blocks new-block ablock
)
789 (push "<IF Duplication>" (node-source-path node
))
790 (push "<IF Duplication>" (node-source-path new-node
))
792 (reoptimize-lvar test
)
793 (reoptimize-lvar new-lvar
)
794 (setf (component-reanalyze *current-component
*) t
)))
797 ;;;; exit IR1 optimization
799 ;;; This function attempts to delete an exit node, returning true if
800 ;;; it deletes the block as a consequence:
801 ;;; -- If the exit is degenerate (has no ENTRY), then we don't do
802 ;;; anything, since there is nothing to be done.
803 ;;; -- If the exit node and its ENTRY have the same home lambda then
804 ;;; we know the exit is local, and can delete the exit. We change
805 ;;; uses of the Exit-Value to be uses of the original lvar,
806 ;;; then unlink the node. If the exit is to a TR context, then we
807 ;;; must do MERGE-TAIL-SETS on any local calls which delivered
808 ;;; their value to this exit.
809 ;;; -- If there is no value (as in a GO), then we skip the value
812 ;;; This function is also called by environment analysis, since it
813 ;;; wants all exits to be optimized even if normal optimization was
815 (defun maybe-delete-exit (node)
816 (declare (type exit node
))
817 (let ((value (exit-value node
))
818 (entry (exit-entry node
)))
820 (eq (node-home-lambda node
) (node-home-lambda entry
)))
821 (setf (entry-exits entry
) (delq node
(entry-exits entry
)))
823 (with-ir1-environment-from-node entry
824 ;; We can't simply use DELETE-FILTER to unlink the node
825 ;; and substitute some LVAR magic, as this can confuse the
826 ;; stack analysis if there's another EXIT to the same
827 ;; continuation. Instead, we fabricate a new block (in
828 ;; the same lexenv as the ENTRY, so it can't be merged
829 ;; backwards), insert a gimmicked CAST node to link up the
830 ;; LVAR holding the value being returned to the LVAR which
831 ;; is expecting to accept the value, thus placing the
832 ;; return value where it needs to be while still providing
833 ;; the hook required for stack analysis.
834 ;; -- AJB, 2014-Mar-03
835 (let* ((exit-block (node-block node
))
836 (new-ctran (make-ctran))
837 (new-block (ctran-starts-block new-ctran
))
840 :asserted-type
*wild-type
*
841 :type-to-check
*wild-type
*
843 :vestigial-exit-lexenv
(node-lexenv node
)
844 :vestigial-exit-entry-lexenv
(node-lexenv entry
)
846 ;; We only expect a single successor to EXIT-BLOCK,
847 ;; because it contains an EXIT node (which must end its
848 ;; block) and the only blocks that have more than once
849 ;; successor are those with IF nodes (which also must
850 ;; end their blocks). Still, just to be sure, we use a
851 ;; construct that guarantees an error if this
852 ;; expectation is violated.
855 (block-succ exit-block
)
857 ;; Finish creating the new block.
858 (link-node-to-previous-ctran cast-node new-ctran
)
859 (setf (block-last new-block
) cast-node
)
861 ;; Link the new block into the control sequence.
862 (unlink-blocks exit-block entry-block
)
863 (link-blocks exit-block new-block
)
864 (link-blocks new-block entry-block
)
866 ;; Finish re-pointing the value-holding LVAR to the
868 (setf (lvar-dest value
) cast-node
)
869 (setf (exit-value node
) nil
)
870 (reoptimize-lvar value
)
872 ;; Register the CAST node as providing a value to the
873 ;; LVAR for the continuation.
874 (add-lvar-use cast-node
(node-lvar node
))
875 (reoptimize-lvar (node-lvar node
))
877 ;; Remove the EXIT node.
880 ;; And, because we created a new block, we need to
881 ;; force component reanalysis (to assign a DFO number
882 ;; to the block if nothing else).
883 (setf (component-reanalyze *current-component
*) t
))))
884 (unlink-node node
)))))
887 ;;;; combination IR1 optimization
889 ;;; Report as we try each transform?
891 (defvar *show-transforms-p
* nil
)
893 (defun check-important-result (node info
)
894 (when (and (null (node-lvar node
))
895 (ir1-attributep (fun-info-attributes info
) important-result
))
896 (let ((*compiler-error-context
* node
))
898 "The return value of ~A should not be discarded."
899 (lvar-fun-name (basic-combination-fun node
))))))
901 ;;; Do IR1 optimizations on a COMBINATION node.
902 (declaim (ftype (function (combination) (values)) ir1-optimize-combination
))
903 (defun ir1-optimize-combination (node)
904 (when (lvar-reoptimize (basic-combination-fun node
))
905 (propagate-fun-change node
)
906 (maybe-terminate-block node nil
))
907 (let ((args (basic-combination-args node
))
908 (kind (basic-combination-kind node
))
909 (info (basic-combination-fun-info node
)))
912 (let ((fun (combination-lambda node
)))
913 (if (eq (functional-kind fun
) :let
)
914 (propagate-let-args node fun
)
915 (propagate-local-call-args node fun
))))
919 (setf (lvar-reoptimize arg
) nil
))))
923 (setf (lvar-reoptimize arg
) nil
)))
925 (check-important-result node info
)
926 (let ((fun (fun-info-destroyed-constant-args info
)))
928 (let ((destroyed-constant-args (funcall fun args
)))
929 (when destroyed-constant-args
930 (let ((*compiler-error-context
* node
))
931 (warn 'constant-modified
932 :fun-name
(lvar-fun-name
933 (basic-combination-fun node
)))
934 (setf (basic-combination-kind node
) :error
)
935 (return-from ir1-optimize-combination
))))))
936 (let ((fun (fun-info-derive-type info
)))
938 (let ((res (funcall fun node
)))
940 (derive-node-type node
(coerce-to-values res
))
941 (maybe-terminate-block node nil
))))))
943 ;; Check against the DEFINED-TYPE unless TYPE is already good.
944 (let* ((fun (basic-combination-fun node
))
945 (uses (lvar-uses fun
))
946 (leaf (when (ref-p uses
) (ref-leaf uses
))))
947 (multiple-value-bind (type defined-type
)
948 (if (global-var-p leaf
)
949 (values (leaf-type leaf
) (leaf-defined-type leaf
))
951 (when (and (not (fun-type-p type
)) (fun-type-p defined-type
))
952 (validate-call-type node type leaf
)))))))
957 (setf (lvar-reoptimize arg
) nil
)))
958 (check-important-result node info
)
959 (let ((fun (fun-info-destroyed-constant-args info
)))
961 ;; If somebody is really sure that they want to modify
962 ;; constants, let them.
963 (policy node
(> check-constant-modification
0)))
964 (let ((destroyed-constant-args (funcall fun args
)))
965 (when destroyed-constant-args
966 (let ((*compiler-error-context
* node
))
967 (warn 'constant-modified
968 :fun-name
(lvar-fun-name
969 (basic-combination-fun node
)))
970 (setf (basic-combination-kind node
) :error
)
971 (return-from ir1-optimize-combination
))))))
973 (let ((attr (fun-info-attributes info
)))
974 (when (and (ir1-attributep attr foldable
)
975 ;; KLUDGE: The next test could be made more sensitive,
976 ;; only suppressing constant-folding of functions with
977 ;; CALL attributes when they're actually passed
978 ;; function arguments. -- WHN 19990918
979 (not (ir1-attributep attr call
))
980 (every #'constant-lvar-p args
)
982 (constant-fold-call node
)
983 (return-from ir1-optimize-combination
))
984 (when (and (ir1-attributep attr commutative
)
986 (constant-lvar-p (first args
))
987 (not (constant-lvar-p (second args
))))
988 (setf (basic-combination-args node
) (nreverse args
))))
989 (let ((fun (fun-info-derive-type info
)))
991 (let ((res (funcall fun node
)))
993 (derive-node-type node
(coerce-to-values res
))
994 (maybe-terminate-block node nil
)))))
996 (let ((fun (fun-info-optimizer info
)))
997 (unless (and fun
(funcall fun node
))
998 ;; First give the VM a peek at the call
999 (multiple-value-bind (style transform
)
1000 (combination-implementation-style node
)
1003 ;; The VM knows how to handle this.
1006 ;; The VM mostly knows how to handle this. We need
1007 ;; to massage the call slightly, though.
1008 (transform-call node transform
(combination-fun-source-name node
)))
1010 ;; Let transforms have a crack at it.
1011 (dolist (x (fun-info-transforms info
))
1013 (when *show-transforms-p
*
1014 (let* ((lvar (basic-combination-fun node
))
1015 (fname (lvar-fun-name lvar t
)))
1016 (/show
"trying transform" x
(transform-function x
) "for" fname
)))
1017 (unless (ir1-transform node x
)
1019 (when *show-transforms-p
*
1020 (/show
"quitting because IR1-TRANSFORM result was NIL"))
1025 (defun xep-tail-combination-p (node)
1026 (and (combination-p node
)
1027 (let* ((lvar (combination-lvar node
))
1028 (dest (when (lvar-p lvar
) (lvar-dest lvar
)))
1029 (lambda (when (return-p dest
) (return-lambda dest
))))
1030 (and (lambda-p lambda
)
1031 (eq :external
(lambda-kind lambda
))))))
1033 ;;; If NODE doesn't return (i.e. return type is NIL), then terminate
1034 ;;; the block there, and link it to the component tail.
1036 ;;; Except when called during IR1 convertion, we delete the
1037 ;;; continuation if it has no other uses. (If it does have other uses,
1040 ;;; Termination on the basis of a continuation type is
1042 ;;; -- The continuation is deleted (hence the assertion is spurious), or
1043 ;;; -- We are in IR1 conversion (where THE assertions are subject to
1044 ;;; weakening.) FIXME: Now THE assertions are not weakened, but new
1045 ;;; uses can(?) be added later. -- APD, 2003-07-17
1047 ;;; Why do we need to consider LVAR type? -- APD, 2003-07-30
1048 (defun maybe-terminate-block (node ir1-converting-not-optimizing-p
)
1049 (declare (type (or basic-combination cast ref
) node
))
1050 (let* ((block (node-block node
))
1051 (lvar (node-lvar node
))
1052 (ctran (node-next node
))
1053 (tail (component-tail (block-component block
)))
1054 (succ (first (block-succ block
))))
1055 (declare (ignore lvar
))
1056 (unless (or (and (eq node
(block-last block
)) (eq succ tail
))
1057 (block-delete-p block
))
1058 ;; Even if the combination will never return, don't terminate if this
1059 ;; is the tail call of a XEP: doing that would inhibit TCO.
1060 (when (and (eq (node-derived-type node
) *empty-type
*)
1061 (not (xep-tail-combination-p node
)))
1062 (cond (ir1-converting-not-optimizing-p
1065 (aver (eq (block-last block
) node
)))
1067 (setf (block-last block
) node
)
1068 (setf (ctran-use ctran
) nil
)
1069 (setf (ctran-kind ctran
) :unused
)
1070 (setf (ctran-block ctran
) nil
)
1071 (setf (node-next node
) nil
)
1072 (link-blocks block
(ctran-starts-block ctran
)))))
1074 (node-ends-block node
)))
1076 (let ((succ (first (block-succ block
))))
1077 (unlink-blocks block succ
)
1078 (setf (component-reanalyze (block-component block
)) t
)
1079 (aver (not (block-succ block
)))
1080 (link-blocks block tail
)
1081 (cond (ir1-converting-not-optimizing-p
1082 (%delete-lvar-use node
))
1083 (t (delete-lvar-use node
)
1084 (when (null (block-pred succ
))
1085 (mark-for-deletion succ
)))))
1088 ;;; This is called both by IR1 conversion and IR1 optimization when
1089 ;;; they have verified the type signature for the call, and are
1090 ;;; wondering if something should be done to special-case the call. If
1091 ;;; CALL is a call to a global function, then see whether it defined
1093 ;;; -- If a DEFINED-FUN should be inline expanded, then convert
1094 ;;; the expansion and change the call to call it. Expansion is
1095 ;;; enabled if :INLINE or if SPACE=0. If the FUNCTIONAL slot is
1096 ;;; true, we never expand, since this function has already been
1097 ;;; converted. Local call analysis will duplicate the definition
1098 ;;; if necessary. We claim that the parent form is LABELS for
1099 ;;; context declarations, since we don't want it to be considered
1100 ;;; a real global function.
1101 ;;; -- If it is a known function, mark it as such by setting the KIND.
1103 ;;; We return the leaf referenced (NIL if not a leaf) and the
1104 ;;; FUN-INFO assigned.
1105 (defun recognize-known-call (call ir1-converting-not-optimizing-p
)
1106 (declare (type combination call
))
1107 (let* ((ref (lvar-uses (basic-combination-fun call
)))
1108 (leaf (when (ref-p ref
) (ref-leaf ref
)))
1109 (inlinep (if (defined-fun-p leaf
)
1110 (defined-fun-inlinep leaf
)
1113 ((eq inlinep
:notinline
)
1114 (let ((info (info :function
:info
(leaf-source-name leaf
))))
1116 (setf (basic-combination-fun-info call
) info
))
1118 ((not (and (global-var-p leaf
)
1119 (eq (global-var-kind leaf
) :global-function
)))
1121 ((and (ecase inlinep
1124 ((nil :maybe-inline
) (policy call
(zerop space
))))
1125 (defined-fun-p leaf
)
1126 (defined-fun-inline-expansion leaf
)
1127 (inline-expansion-ok call
))
1128 ;; Inline: if the function has already been converted at another call
1129 ;; site in this component, we point this REF to the functional. If not,
1130 ;; we convert the expansion.
1132 ;; For :INLINE case local call analysis will copy the expansion later,
1133 ;; but for :MAYBE-INLINE and NIL cases we only get one copy of the
1134 ;; expansion per component.
1136 ;; FIXME: We also convert in :INLINE & FUNCTIONAL-KIND case below. What
1139 (let* ((name (leaf-source-name leaf
))
1140 (res (ir1-convert-inline-expansion
1142 (defined-fun-inline-expansion leaf
)
1145 (info :function
:info name
))))
1146 ;; Allow backward references to this function from following
1147 ;; forms. (Reused only if policy matches.)
1148 (push res
(defined-fun-functionals leaf
))
1149 (change-ref-leaf ref res
))))
1150 (let ((fun (defined-fun-functional leaf
)))
1152 (and (eq inlinep
:inline
) (functional-kind fun
)))
1154 (if ir1-converting-not-optimizing-p
1156 (with-ir1-environment-from-node call
1158 (locall-analyze-component *current-component
*)))
1159 ;; If we've already converted, change ref to the converted
1161 (change-ref-leaf ref fun
))))
1162 (values (ref-leaf ref
) nil
))
1164 (let ((info (info :function
:info
(leaf-source-name leaf
))))
1168 (setf (basic-combination-kind call
) :known
)
1169 (setf (basic-combination-fun-info call
) info
)))
1170 (values leaf nil
)))))))
1172 ;;; Check whether CALL satisfies TYPE. If so, apply the type to the
1173 ;;; call, and do MAYBE-TERMINATE-BLOCK and return the values of
1174 ;;; RECOGNIZE-KNOWN-CALL. If an error, set the combination kind and
1175 ;;; return NIL, NIL. If the type is just FUNCTION, then skip the
1176 ;;; syntax check, arg/result type processing, but still call
1177 ;;; RECOGNIZE-KNOWN-CALL, since the call might be to a known lambda,
1178 ;;; and that checking is done by local call analysis.
1179 (defun validate-call-type (call type fun
&optional ir1-converting-not-optimizing-p
)
1180 (declare (type combination call
) (type ctype type
))
1181 (let* ((where (when fun
(leaf-where-from fun
)))
1182 (same-file-p (eq :defined-here where
)))
1183 (cond ((not (fun-type-p type
))
1184 (aver (multiple-value-bind (val win
)
1185 (csubtypep type
(specifier-type 'function
))
1186 (or val
(not win
))))
1187 ;; Using the defined-type too early is a bit of a waste: during
1188 ;; conversion we cannot use the untrusted ASSERT-CALL-TYPE, etc.
1189 (when (and fun
(not ir1-converting-not-optimizing-p
))
1190 (let ((defined-type (leaf-defined-type fun
)))
1191 (when (and (fun-type-p defined-type
)
1192 (neq fun
(combination-type-validated-for-leaf call
)))
1193 ;; Don't validate multiple times against the same leaf --
1194 ;; it doesn't add any information, but may generate the same warning
1196 (setf (combination-type-validated-for-leaf call
) fun
)
1197 (when (and (valid-fun-use call defined-type
1198 :argument-test
#'always-subtypep
1200 :lossage-fun
(if same-file-p
1202 #'compiler-style-warn
)
1203 :unwinnage-fun
#'compiler-notify
)
1205 (assert-call-type call defined-type nil
)
1206 (maybe-terminate-block call ir1-converting-not-optimizing-p
)))))
1207 (recognize-known-call call ir1-converting-not-optimizing-p
))
1208 ((valid-fun-use call type
1209 :argument-test
#'always-subtypep
1211 :lossage-fun
#'compiler-warn
1212 :unwinnage-fun
#'compiler-notify
)
1213 (assert-call-type call type
)
1214 (maybe-terminate-block call ir1-converting-not-optimizing-p
)
1215 (recognize-known-call call ir1-converting-not-optimizing-p
))
1217 (setf (combination-kind call
) :error
)
1218 (values nil nil
)))))
1220 ;;; This is called by IR1-OPTIMIZE when the function for a call has
1221 ;;; changed. If the call is local, we try to LET-convert it, and
1222 ;;; derive the result type. If it is a :FULL call, we validate it
1223 ;;; against the type, which recognizes known calls, does inline
1224 ;;; expansion, etc. If a call to a predicate in a non-conditional
1225 ;;; position or to a function with a source transform, then we
1226 ;;; reconvert the form to give IR1 another chance.
1227 (defun propagate-fun-change (call)
1228 (declare (type combination call
))
1229 (let ((*compiler-error-context
* call
)
1230 (fun-lvar (basic-combination-fun call
)))
1231 (setf (lvar-reoptimize fun-lvar
) nil
)
1232 (case (combination-kind call
)
1234 (let ((fun (combination-lambda call
)))
1235 (maybe-let-convert fun
)
1236 (unless (member (functional-kind fun
) '(:let
:assignment
:deleted
))
1237 (derive-node-type call
(tail-set-type (lambda-tail-set fun
))))))
1239 (multiple-value-bind (leaf info
)
1240 (let* ((uses (lvar-uses fun-lvar
))
1241 (leaf (when (ref-p uses
) (ref-leaf uses
))))
1242 (validate-call-type call
(lvar-type fun-lvar
) leaf
))
1243 (cond ((functional-p leaf
)
1244 (convert-call-if-possible
1245 (lvar-uses (basic-combination-fun call
))
1248 ((and (global-var-p leaf
)
1249 (eq (global-var-kind leaf
) :global-function
)
1250 (leaf-has-source-name-p leaf
)
1251 (or (info :function
:source-transform
(leaf-source-name leaf
))
1253 (ir1-attributep (fun-info-attributes info
)
1255 (let ((lvar (node-lvar call
)))
1256 (and lvar
(not (if-p (lvar-dest lvar
))))))))
1257 (let ((name (leaf-source-name leaf
))
1258 (dummies (make-gensym-list
1259 (length (combination-args call
)))))
1260 (transform-call call
1262 (,@(if (symbolp name
)
1266 (leaf-source-name leaf
)))))))))
1269 ;;;; known function optimization
1271 ;;; Add a failed optimization note to FAILED-OPTIMZATIONS for NODE,
1272 ;;; FUN and ARGS. If there is already a note for NODE and TRANSFORM,
1273 ;;; replace it, otherwise add a new one.
1274 (defun record-optimization-failure (node transform args
)
1275 (declare (type combination node
) (type transform transform
)
1276 (type (or fun-type list
) args
))
1277 (let* ((table (component-failed-optimizations *component-being-compiled
*))
1278 (found (assoc transform
(gethash node table
))))
1280 (setf (cdr found
) args
)
1281 (push (cons transform args
) (gethash node table
))))
1284 ;;; Attempt to transform NODE using TRANSFORM-FUNCTION, subject to the
1285 ;;; call type constraint TRANSFORM-TYPE. If we are inhibited from
1286 ;;; doing the transform for some reason and FLAME is true, then we
1287 ;;; make a note of the message in FAILED-OPTIMIZATIONS for IR1
1288 ;;; finalize to pick up. We return true if the transform failed, and
1289 ;;; thus further transformation should be attempted. We return false
1290 ;;; if either the transform succeeded or was aborted.
1291 (defun ir1-transform (node transform
)
1292 (declare (type combination node
) (type transform transform
))
1293 (let* ((type (transform-type transform
))
1294 (fun (transform-function transform
))
1295 (constrained (fun-type-p type
))
1296 (table (component-failed-optimizations *component-being-compiled
*))
1297 (flame (case (transform-important transform
)
1298 ((t) (policy node
(>= speed inhibit-warnings
)))
1299 (:slightly
(policy node
(> speed inhibit-warnings
)))))
1300 (*compiler-error-context
* node
))
1301 (cond ((or (not constrained
)
1302 (valid-fun-use node type
))
1303 (multiple-value-bind (severity args
)
1304 (catch 'give-up-ir1-transform
1305 (transform-call node
1307 (combination-fun-source-name node
))
1311 (remhash node table
)
1314 (setf (combination-kind node
) :error
)
1316 (apply #'warn args
))
1317 (remhash node table
)
1322 (record-optimization-failure node transform args
))
1323 (setf (gethash node table
)
1324 (remove transform
(gethash node table
) :key
#'car
)))
1327 (remhash node table
)
1332 :argument-test
#'types-equal-or-intersect
1333 :result-test
#'values-types-equal-or-intersect
))
1334 (record-optimization-failure node transform type
)
1339 ;;; When we don't like an IR1 transform, we throw the severity/reason
1342 ;;; GIVE-UP-IR1-TRANSFORM is used to throw out of an IR1 transform,
1343 ;;; aborting this attempt to transform the call, but admitting the
1344 ;;; possibility that this or some other transform will later succeed.
1345 ;;; If arguments are supplied, they are format arguments for an
1346 ;;; efficiency note.
1348 ;;; ABORT-IR1-TRANSFORM is used to throw out of an IR1 transform and
1349 ;;; force a normal call to the function at run time. No further
1350 ;;; optimizations will be attempted.
1352 ;;; DELAY-IR1-TRANSFORM is used to throw out of an IR1 transform, and
1353 ;;; delay the transform on the node until later. REASONS specifies
1354 ;;; when the transform will be later retried. The :OPTIMIZE reason
1355 ;;; causes the transform to be delayed until after the current IR1
1356 ;;; optimization pass. The :CONSTRAINT reason causes the transform to
1357 ;;; be delayed until after constraint propagation.
1359 ;;; FIXME: Now (0.6.11.44) that there are 4 variants of this (GIVE-UP,
1360 ;;; ABORT, DELAY/:OPTIMIZE, DELAY/:CONSTRAINT) and we're starting to
1361 ;;; do CASE operations on the various REASON values, it might be a
1362 ;;; good idea to go OO, representing the reasons by objects, using
1363 ;;; CLOS methods on the objects instead of CASE, and (possibly) using
1364 ;;; SIGNAL instead of THROW.
1365 (declaim (ftype (function (&rest t
) nil
) give-up-ir1-transform
))
1366 (defun give-up-ir1-transform (&rest args
)
1367 (throw 'give-up-ir1-transform
(values :failure args
)))
1368 (defun abort-ir1-transform (&rest args
)
1369 (throw 'give-up-ir1-transform
(values :aborted args
)))
1370 (defun delay-ir1-transform (node &rest reasons
)
1371 (let ((assoc (assoc node
*delayed-ir1-transforms
*)))
1373 (setf *delayed-ir1-transforms
*
1374 (acons node reasons
*delayed-ir1-transforms
*))
1375 (throw 'give-up-ir1-transform
:delayed
))
1377 (dolist (reason reasons
)
1378 (pushnew reason
(cdr assoc
)))
1379 (throw 'give-up-ir1-transform
:delayed
)))))
1381 ;;; Poor man's catching and resignalling
1382 ;;; Implicit GIVE-UP macrolet will resignal the give-up "condition"
1383 (defmacro catch-give-up-ir1-transform
(form &body gave-up-body
)
1384 (let ((block (gensym "BLOCK"))
1385 (kind (gensym "KIND"))
1386 (args (gensym "ARGS")))
1388 (multiple-value-bind (,kind
,args
)
1389 (catch 'give-up-ir1-transform
1390 (return-from ,block
,form
))
1393 (throw 'give-up-ir1-transform
:delayed
))
1394 ((:failure
:aborted
)
1395 (macrolet ((give-up ()
1396 `(throw 'give-up-ir1-transform
(values ,',kind
1398 ,@gave-up-body
)))))))
1400 ;;; Clear any delayed transform with no reasons - these should have
1401 ;;; been tried in the last pass. Then remove the reason from the
1402 ;;; delayed transform reasons, and if any become empty then set
1403 ;;; reoptimize flags for the node. Return true if any transforms are
1405 (defun retry-delayed-ir1-transforms (reason)
1406 (setf *delayed-ir1-transforms
*
1407 (remove-if-not #'cdr
*delayed-ir1-transforms
*))
1408 (let ((reoptimize nil
))
1409 (dolist (assoc *delayed-ir1-transforms
*)
1410 (let ((reasons (remove reason
(cdr assoc
))))
1411 (setf (cdr assoc
) reasons
)
1413 (let ((node (car assoc
)))
1414 (unless (node-deleted node
)
1416 (setf (node-reoptimize node
) t
)
1417 (let ((block (node-block node
)))
1418 (setf (block-reoptimize block
) t
)
1419 (reoptimize-component (block-component block
) :maybe
)))))))
1422 ;;; Take the lambda-expression RES, IR1 convert it in the proper
1423 ;;; environment, and then install it as the function for the call
1424 ;;; NODE. We do local call analysis so that the new function is
1425 ;;; integrated into the control flow.
1427 ;;; We require the original function source name in order to generate
1428 ;;; a meaningful debug name for the lambda we set up. (It'd be
1429 ;;; possible to do this starting from debug names as well as source
1430 ;;; names, but as of sbcl-0.7.1.5, there was no need for this
1431 ;;; generality, since source names are always known to our callers.)
1432 (defun transform-call (call res source-name
)
1433 (declare (type combination call
) (list res
))
1434 (aver (and (legal-fun-name-p source-name
)
1435 (not (eql source-name
'.anonymous.
))))
1436 (node-ends-block call
)
1437 ;; The internal variables of a transform are not going to be
1438 ;; interesting to the debugger, so there's no sense in
1439 ;; suppressing the substitution of variables with only one use
1440 ;; (the extra variables can slow down constraint propagation).
1442 ;; This needs to be done before the WITH-IR1-ENVIRONMENT-FROM-NODE,
1443 ;; so that it will bind *LEXENV* to the right environment.
1444 (setf (combination-lexenv call
)
1445 (make-lexenv :default
(combination-lexenv call
)
1446 :policy
(process-optimize-decl
1448 (preserve-single-use-debug-variables 0))
1450 (combination-lexenv call
)))))
1451 (with-ir1-environment-from-node call
1452 (with-component-last-block (*current-component
*
1453 (block-next (node-block call
)))
1455 (let ((new-fun (ir1-convert-inline-lambda
1457 :debug-name
(debug-name 'lambda-inlined source-name
)
1459 (ref (lvar-use (combination-fun call
))))
1460 (change-ref-leaf ref new-fun
)
1461 (setf (combination-kind call
) :full
)
1462 (locall-analyze-component *current-component
*))))
1465 ;;; Replace a call to a foldable function of constant arguments with
1466 ;;; the result of evaluating the form. If there is an error during the
1467 ;;; evaluation, we give a warning and leave the call alone, making the
1468 ;;; call a :ERROR call.
1470 ;;; If there is more than one value, then we transform the call into a
1472 (defun constant-fold-call (call)
1473 (let ((args (mapcar #'lvar-value
(combination-args call
)))
1474 (fun-name (combination-fun-source-name call
)))
1475 (multiple-value-bind (values win
)
1476 (careful-call fun-name
1479 ;; Note: CMU CL had COMPILER-WARN here, and that
1480 ;; seems more natural, but it's probably not.
1482 ;; It's especially not while bug 173 exists:
1485 ;; (UNLESS (OR UNSAFE? (<= END SIZE)))
1487 ;; can cause constant-folding TYPE-ERRORs (in
1488 ;; #'<=) when END can be proved to be NIL, even
1489 ;; though the code is perfectly legal and safe
1490 ;; because a NIL value of END means that the
1491 ;; #'<= will never be executed.
1493 ;; Moreover, even without bug 173,
1494 ;; quite-possibly-valid code like
1495 ;; (COND ((NONINLINED-PREDICATE END)
1496 ;; (UNLESS (<= END SIZE))
1498 ;; (where NONINLINED-PREDICATE is something the
1499 ;; compiler can't do at compile time, but which
1500 ;; turns out to make the #'<= expression
1501 ;; unreachable when END=NIL) could cause errors
1502 ;; when the compiler tries to constant-fold (<=
1505 ;; So, with or without bug 173, it'd be
1506 ;; unnecessarily evil to do a full
1507 ;; COMPILER-WARNING (and thus return FAILURE-P=T
1508 ;; from COMPILE-FILE) for legal code, so we we
1509 ;; use a wimpier COMPILE-STYLE-WARNING instead.
1510 #-sb-xc-host
#'compiler-style-warn
1511 ;; On the other hand, for code we control, we
1512 ;; should be able to work around any bug
1513 ;; 173-related problems, and in particular we
1514 ;; want to be alerted to calls to our own
1515 ;; functions which aren't being folded away; a
1516 ;; COMPILER-WARNING is butch enough to stop the
1517 ;; SBCL build itself in its tracks.
1518 #+sb-xc-host
#'compiler-warn
1521 (setf (combination-kind call
) :error
))
1522 ((and (proper-list-of-length-p values
1))
1523 (with-ir1-environment-from-node call
1524 (let* ((lvar (node-lvar call
))
1525 (prev (node-prev call
))
1526 (intermediate-ctran (make-ctran)))
1527 (%delete-lvar-use call
)
1528 (setf (ctran-next prev
) nil
)
1529 (setf (node-prev call
) nil
)
1530 (reference-constant prev intermediate-ctran lvar
1532 (link-node-to-previous-ctran call intermediate-ctran
)
1533 (reoptimize-lvar lvar
)
1534 (flush-combination call
))))
1535 (t (let ((dummies (make-gensym-list (length args
))))
1539 (declare (ignore ,@dummies
))
1540 (values ,@(mapcar (lambda (x) `',x
) values
)))
1544 ;;;; local call optimization
1546 ;;; Propagate TYPE to LEAF and its REFS, marking things changed.
1548 ;;; If the leaf type is a function type, then just leave it alone, since TYPE
1549 ;;; is never going to be more specific than that (and TYPE-INTERSECTION would
1552 ;;; Also, if the type is one requiring special care don't touch it if the leaf
1553 ;;; has multiple references -- otherwise LVAR-CONSERVATIVE-TYPE is screwed.
1554 (defun propagate-to-refs (leaf type
)
1555 (declare (type leaf leaf
) (type ctype type
))
1556 (let ((var-type (leaf-type leaf
))
1557 (refs (leaf-refs leaf
)))
1558 (unless (or (fun-type-p var-type
)
1560 (eq :declared
(leaf-where-from leaf
))
1561 (type-needs-conservation-p var-type
)))
1562 (let ((int (type-approx-intersection2 var-type type
)))
1563 (when (type/= int var-type
)
1564 (setf (leaf-type leaf
) int
)
1565 (let ((s-int (make-single-value-type int
)))
1567 (derive-node-type ref s-int
)
1568 ;; KLUDGE: LET var substitution
1569 (let* ((lvar (node-lvar ref
)))
1570 (when (and lvar
(combination-p (lvar-dest lvar
)))
1571 (reoptimize-lvar lvar
)))))))
1574 ;;; Iteration variable: exactly one SETQ of the form:
1576 ;;; (let ((var initial))
1578 ;;; (setq var (+ var step))
1580 (defun maybe-infer-iteration-var-type (var initial-type
)
1581 (binding* ((sets (lambda-var-sets var
) :exit-if-null
)
1583 (() (null (rest sets
)) :exit-if-null
)
1584 (set-use (principal-lvar-use (set-value set
)))
1585 (() (and (combination-p set-use
)
1586 (eq (combination-kind set-use
) :known
)
1587 (fun-info-p (combination-fun-info set-use
))
1588 (not (node-to-be-deleted-p set-use
))
1589 (or (eq (combination-fun-source-name set-use
) '+)
1590 (eq (combination-fun-source-name set-use
) '-
)))
1592 (minusp (eq (combination-fun-source-name set-use
) '-
))
1593 (+-args
(basic-combination-args set-use
))
1594 (() (and (proper-list-of-length-p +-args
2 2)
1595 (let ((first (principal-lvar-use
1598 (eq (ref-leaf first
) var
))))
1600 (step-type (lvar-type (second +-args
)))
1601 (set-type (lvar-type (set-value set
))))
1602 (when (and (numeric-type-p initial-type
)
1603 (numeric-type-p step-type
)
1604 (or (numeric-type-equal initial-type step-type
)
1605 ;; Detect cases like (LOOP FOR 1.0 to 5.0 ...), where
1606 ;; the initial and the step are of different types,
1607 ;; and the step is less contagious.
1608 (numeric-type-equal initial-type
1609 (numeric-contagion initial-type
1611 (labels ((leftmost (x y cmp cmp
=)
1612 (cond ((eq x nil
) nil
)
1615 (let ((x1 (first x
)))
1617 (let ((y1 (first y
)))
1618 (if (funcall cmp x1 y1
) x y
)))
1620 (if (funcall cmp x1 y
) x y
)))))
1622 (let ((y1 (first y
)))
1623 (if (funcall cmp
= x y1
) x y
)))
1624 (t (if (funcall cmp x y
) x y
))))
1625 (max* (x y
) (leftmost x y
#'> #'>=))
1626 (min* (x y
) (leftmost x y
#'< #'<=)))
1627 (multiple-value-bind (low high
)
1628 (let ((step-type-non-negative (csubtypep step-type
(specifier-type
1630 (step-type-non-positive (csubtypep step-type
(specifier-type
1632 (cond ((or (and step-type-non-negative
(not minusp
))
1633 (and step-type-non-positive minusp
))
1634 (values (numeric-type-low initial-type
)
1635 (when (and (numeric-type-p set-type
)
1636 (numeric-type-equal set-type initial-type
))
1637 (max* (numeric-type-high initial-type
)
1638 (numeric-type-high set-type
)))))
1639 ((or (and step-type-non-positive
(not minusp
))
1640 (and step-type-non-negative minusp
))
1641 (values (when (and (numeric-type-p set-type
)
1642 (numeric-type-equal set-type initial-type
))
1643 (min* (numeric-type-low initial-type
)
1644 (numeric-type-low set-type
)))
1645 (numeric-type-high initial-type
)))
1648 (modified-numeric-type initial-type
1651 :enumerable nil
))))))
1652 (deftransform + ((x y
) * * :result result
)
1653 "check for iteration variable reoptimization"
1654 (let ((dest (principal-lvar-end result
))
1655 (use (principal-lvar-use x
)))
1656 (when (and (ref-p use
)
1660 (reoptimize-lvar (set-value dest
))))
1661 (give-up-ir1-transform))
1663 ;;; Figure out the type of a LET variable that has sets. We compute
1664 ;;; the union of the INITIAL-TYPE and the types of all the set
1665 ;;; values and to a PROPAGATE-TO-REFS with this type.
1666 (defun propagate-from-sets (var initial-type
)
1667 (let ((changes (not (csubtypep (lambda-var-last-initial-type var
) initial-type
)))
1669 (dolist (set (lambda-var-sets var
))
1670 (let ((type (lvar-type (set-value set
))))
1672 (when (node-reoptimize set
)
1673 (let ((old-type (node-derived-type set
)))
1674 (unless (values-subtypep old-type type
)
1675 (derive-node-type set
(make-single-value-type type
))
1677 (setf (node-reoptimize set
) nil
))))
1679 (setf (lambda-var-last-initial-type var
) initial-type
)
1680 (let ((res-type (or (maybe-infer-iteration-var-type var initial-type
)
1681 (apply #'type-union initial-type types
))))
1682 (propagate-to-refs var res-type
))))
1685 ;;; If a LET variable, find the initial value's type and do
1686 ;;; PROPAGATE-FROM-SETS. We also derive the VALUE's type as the node's
1688 (defun ir1-optimize-set (node)
1689 (declare (type cset node
))
1690 (let ((var (set-var node
)))
1691 (when (and (lambda-var-p var
) (leaf-refs var
))
1692 (let ((home (lambda-var-home var
)))
1693 (when (eq (functional-kind home
) :let
)
1694 (let* ((initial-value (let-var-initial-value var
))
1695 (initial-type (lvar-type initial-value
)))
1696 (setf (lvar-reoptimize initial-value
) nil
)
1697 (propagate-from-sets var initial-type
))))))
1698 (derive-node-type node
(make-single-value-type
1699 (lvar-type (set-value node
))))
1700 (setf (node-reoptimize node
) nil
)
1703 ;;; Return true if the value of REF will always be the same (and is
1704 ;;; thus legal to substitute.)
1705 (defun constant-reference-p (ref)
1706 (declare (type ref ref
))
1707 (let ((leaf (ref-leaf ref
)))
1709 ((or constant functional
) t
)
1711 (null (lambda-var-sets leaf
)))
1713 (not (eq (defined-fun-inlinep leaf
) :notinline
)))
1715 (case (global-var-kind leaf
)
1717 (let ((name (leaf-source-name leaf
)))
1719 (eq (symbol-package (fun-name-block-name name
))
1721 (info :function
:info name
)))))))))
1723 ;;; If we have a non-set LET var with a single use, then (if possible)
1724 ;;; replace the variable reference's LVAR with the arg lvar.
1726 ;;; We change the REF to be a reference to NIL with unused value, and
1727 ;;; let it be flushed as dead code. A side effect of this substitution
1728 ;;; is to delete the variable.
1729 (defun substitute-single-use-lvar (arg var
)
1730 (declare (type lvar arg
) (type lambda-var var
))
1731 (binding* ((ref (first (leaf-refs var
)))
1732 (lvar (node-lvar ref
) :exit-if-null
)
1733 (dest (lvar-dest lvar
))
1734 (dest-lvar (when (valued-node-p dest
) (node-lvar dest
))))
1736 ;; Think about (LET ((A ...)) (IF ... A ...)): two
1737 ;; LVAR-USEs should not be met on one path. Another problem
1738 ;; is with dynamic-extent.
1739 (eq (lvar-uses lvar
) ref
)
1740 (not (block-delete-p (node-block ref
)))
1741 ;; If the destinatation is dynamic extent, don't substitute unless
1742 ;; the source is as well.
1744 (not (lvar-dynamic-extent dest-lvar
))
1745 (lvar-dynamic-extent lvar
))
1747 ;; we should not change lifetime of unknown values lvars
1749 (and (type-single-value-p (lvar-derived-type arg
))
1750 (multiple-value-bind (pdest pprev
)
1751 (principal-lvar-end lvar
)
1752 (declare (ignore pdest
))
1753 (lvar-single-value-p pprev
))))
1755 (or (eq (basic-combination-fun dest
) lvar
)
1756 (and (eq (basic-combination-kind dest
) :local
)
1757 (type-single-value-p (lvar-derived-type arg
)))))
1759 ;; While CRETURN and EXIT nodes may be known-values,
1760 ;; they have their own complications, such as
1761 ;; substitution into CRETURN may create new tail calls.
1764 (aver (lvar-single-value-p lvar
))
1766 (eq (node-home-lambda ref
)
1767 (lambda-home (lambda-var-home var
))))
1768 (let ((ref-type (single-value-type (node-derived-type ref
))))
1769 (cond ((csubtypep (single-value-type (lvar-type arg
)) ref-type
)
1770 (substitute-lvar-uses lvar arg
1771 ;; Really it is (EQ (LVAR-USES LVAR) REF):
1773 (delete-lvar-use ref
))
1775 (let* ((value (make-lvar))
1776 (cast (insert-cast-before ref value ref-type
1777 ;; KLUDGE: it should be (TYPE-CHECK 0)
1779 (setf (cast-type-to-check cast
) *wild-type
*)
1780 (substitute-lvar-uses value arg
1783 (%delete-lvar-use ref
)
1784 (add-lvar-use cast lvar
)))))
1785 (setf (node-derived-type ref
) *wild-type
*)
1786 (change-ref-leaf ref
(find-constant nil
))
1789 (reoptimize-lvar lvar
)
1792 ;;; Delete a LET, removing the call and bind nodes, and warning about
1793 ;;; any unreferenced variables. Note that FLUSH-DEAD-CODE will come
1794 ;;; along right away and delete the REF and then the lambda, since we
1795 ;;; flush the FUN lvar.
1796 (defun delete-let (clambda)
1797 (declare (type clambda clambda
))
1798 (aver (functional-letlike-p clambda
))
1799 (note-unreferenced-fun-vars clambda
)
1800 (let ((call (let-combination clambda
)))
1801 (flush-dest (basic-combination-fun call
))
1803 (unlink-node (lambda-bind clambda
))
1804 (setf (lambda-bind clambda
) nil
))
1805 (setf (functional-kind clambda
) :zombie
)
1806 (let ((home (lambda-home clambda
)))
1807 (setf (lambda-lets home
) (delete clambda
(lambda-lets home
))))
1810 ;;; This function is called when one of the arguments to a LET
1811 ;;; changes. We look at each changed argument. If the corresponding
1812 ;;; variable is set, then we call PROPAGATE-FROM-SETS. Otherwise, we
1813 ;;; consider substituting for the variable, and also propagate
1814 ;;; derived-type information for the arg to all the VAR's refs.
1816 ;;; Substitution is inhibited when the arg leaf's derived type isn't a
1817 ;;; subtype of the argument's leaf type. This prevents type checking
1818 ;;; from being defeated, and also ensures that the best representation
1819 ;;; for the variable can be used.
1821 ;;; Substitution of individual references is inhibited if the
1822 ;;; reference is in a different component from the home. This can only
1823 ;;; happen with closures over top level lambda vars. In such cases,
1824 ;;; the references may have already been compiled, and thus can't be
1825 ;;; retroactively modified.
1827 ;;; If all of the variables are deleted (have no references) when we
1828 ;;; are done, then we delete the LET.
1830 ;;; Note that we are responsible for clearing the LVAR-REOPTIMIZE
1832 (defun propagate-let-args (call fun
)
1833 (declare (type combination call
) (type clambda fun
))
1834 (loop for arg in
(combination-args call
)
1835 and var in
(lambda-vars fun
) do
1836 (when (and arg
(lvar-reoptimize arg
))
1837 (setf (lvar-reoptimize arg
) nil
)
1839 ((lambda-var-sets var
)
1840 (propagate-from-sets var
(lvar-type arg
)))
1841 ((let ((use (lvar-uses arg
)))
1843 (let ((leaf (ref-leaf use
)))
1844 (when (and (constant-reference-p use
)
1845 (csubtypep (leaf-type leaf
)
1846 ;; (NODE-DERIVED-TYPE USE) would
1847 ;; be better -- APD, 2003-05-15
1849 (propagate-to-refs var
(lvar-type arg
))
1850 (let ((use-component (node-component use
)))
1851 (prog1 (substitute-leaf-if
1853 (cond ((eq (node-component ref
) use-component
)
1856 (aver (lambda-toplevelish-p (lambda-home fun
)))
1860 ((and (null (rest (leaf-refs var
)))
1861 (not (preserve-single-use-debug-var-p call var
))
1862 (substitute-single-use-lvar arg var
)))
1864 (propagate-to-refs var
(lvar-type arg
))))))
1866 (when (every #'not
(combination-args call
))
1871 ;;; This function is called when one of the args to a non-LET local
1872 ;;; call changes. For each changed argument corresponding to an unset
1873 ;;; variable, we compute the union of the types across all calls and
1874 ;;; propagate this type information to the var's refs.
1876 ;;; If the function has an entry-fun, then we don't do anything: since
1877 ;;; it has a XEP we would not discover anything.
1879 ;;; If the function is an optional-entry-point, we will just make sure
1880 ;;; &REST lists are known to be lists. Doing the regular rigamarole
1881 ;;; can erronously propagate too strict types into refs: see
1882 ;;; BUG-655203-REGRESSION in tests/compiler.pure.lisp.
1884 ;;; We can clear the LVAR-REOPTIMIZE flags for arguments in all calls
1885 ;;; corresponding to changed arguments in CALL, since the only use in
1886 ;;; IR1 optimization of the REOPTIMIZE flag for local call args is
1888 (defun propagate-local-call-args (call fun
)
1889 (declare (type combination call
) (type clambda fun
))
1890 (unless (functional-entry-fun fun
)
1891 (if (lambda-optional-dispatch fun
)
1892 ;; We can still make sure &REST is known to be a list.
1893 (loop for var in
(lambda-vars fun
)
1894 do
(let ((info (lambda-var-arg-info var
)))
1895 (when (and info
(eq :rest
(arg-info-kind info
)))
1896 (propagate-from-sets var
(specifier-type 'list
)))))
1898 (let* ((vars (lambda-vars fun
))
1899 (union (mapcar (lambda (arg var
)
1901 (lvar-reoptimize arg
)
1902 (null (basic-var-sets var
)))
1904 (basic-combination-args call
)
1906 (this-ref (lvar-use (basic-combination-fun call
))))
1908 (dolist (arg (basic-combination-args call
))
1910 (setf (lvar-reoptimize arg
) nil
)))
1912 (dolist (ref (leaf-refs fun
))
1913 (let ((dest (node-dest ref
)))
1914 (unless (or (eq ref this-ref
) (not dest
))
1916 (mapcar (lambda (this-arg old
)
1918 (setf (lvar-reoptimize this-arg
) nil
)
1919 (type-union (lvar-type this-arg
) old
)))
1920 (basic-combination-args dest
)
1923 (loop for var in vars
1925 when type do
(propagate-to-refs var type
)))))
1929 ;;;; multiple values optimization
1931 ;;; Do stuff to notice a change to a MV combination node. There are
1932 ;;; two main branches here:
1933 ;;; -- If the call is local, then it is already a MV let, or should
1934 ;;; become one. Note that although all :LOCAL MV calls must eventually
1935 ;;; be converted to :MV-LETs, there can be a window when the call
1936 ;;; is local, but has not been LET converted yet. This is because
1937 ;;; the entry-point lambdas may have stray references (in other
1938 ;;; entry points) that have not been deleted yet.
1939 ;;; -- The call is full. This case is somewhat similar to the non-MV
1940 ;;; combination optimization: we propagate return type information and
1941 ;;; notice non-returning calls. We also have an optimization
1942 ;;; which tries to convert MV-CALLs into MV-binds.
1943 (defun ir1-optimize-mv-combination (node)
1944 (let ((fun (basic-combination-fun node
)))
1945 (unless (and (node-p (lvar-uses fun
))
1946 (node-to-be-deleted-p (lvar-uses fun
)))
1947 (ecase (basic-combination-kind node
)
1949 (when (lvar-reoptimize fun
)
1950 (setf (lvar-reoptimize fun
) nil
)
1951 (maybe-let-convert (combination-lambda node
)))
1952 (setf (lvar-reoptimize (first (basic-combination-args node
))) nil
)
1953 (when (eq (functional-kind (combination-lambda node
)) :mv-let
)
1954 (unless (convert-mv-bind-to-let node
)
1955 (ir1-optimize-mv-bind node
))))
1957 (let* ((fun-changed (lvar-reoptimize fun
))
1958 (args (basic-combination-args node
)))
1960 (setf (lvar-reoptimize fun
) nil
)
1961 (let ((type (lvar-type fun
)))
1962 (when (fun-type-p type
)
1963 (derive-node-type node
(fun-type-returns type
))))
1964 (maybe-terminate-block node nil
)
1965 (let ((use (lvar-uses fun
)))
1966 (when (and (ref-p use
) (functional-p (ref-leaf use
)))
1967 (convert-call-if-possible use node
)
1968 (when (eq (basic-combination-kind node
) :local
)
1969 (maybe-let-convert (ref-leaf use
))))))
1970 (unless (or (eq (basic-combination-kind node
) :local
)
1971 (eq (lvar-fun-name fun
) '%throw
))
1972 (ir1-optimize-mv-call node
))
1974 (setf (lvar-reoptimize arg
) nil
))))
1978 ;;; Propagate derived type info from the values lvar to the vars.
1979 (defun ir1-optimize-mv-bind (node)
1980 (declare (type mv-combination node
))
1981 (let* ((arg (first (basic-combination-args node
)))
1982 (vars (lambda-vars (combination-lambda node
)))
1983 (n-vars (length vars
))
1984 (types (values-type-in (lvar-derived-type arg
)
1986 (loop for var in vars
1988 do
(if (basic-var-sets var
)
1989 (propagate-from-sets var type
)
1990 (propagate-to-refs var type
)))
1991 (setf (lvar-reoptimize arg
) nil
))
1994 ;;; If possible, convert a general MV call to an MV-BIND. We can do
1996 ;;; -- The call has only one argument, and
1997 ;;; -- The function has a known fixed number of arguments, or
1998 ;;; -- The argument yields a known fixed number of values.
2000 ;;; What we do is change the function in the MV-CALL to be a lambda
2001 ;;; that "looks like an MV bind", which allows
2002 ;;; IR1-OPTIMIZE-MV-COMBINATION to notice that this call can be
2003 ;;; converted (the next time around.) This new lambda just calls the
2004 ;;; actual function with the MV-BIND variables as arguments. Note that
2005 ;;; this new MV bind is not let-converted immediately, as there are
2006 ;;; going to be stray references from the entry-point functions until
2007 ;;; they get deleted.
2009 ;;; In order to avoid loss of argument count checking, we only do the
2010 ;;; transformation according to a known number of expected argument if
2011 ;;; safety is unimportant. We can always convert if we know the number
2012 ;;; of actual values, since the normal call that we build will still
2013 ;;; do any appropriate argument count checking.
2015 ;;; We only attempt the transformation if the called function is a
2016 ;;; constant reference. This allows us to just splice the leaf into
2017 ;;; the new function, instead of trying to somehow bind the function
2018 ;;; expression. The leaf must be constant because we are evaluating it
2019 ;;; again in a different place. This also has the effect of squelching
2020 ;;; multiple warnings when there is an argument count error.
2021 (defun ir1-optimize-mv-call (node)
2022 (let ((fun (basic-combination-fun node
))
2023 (*compiler-error-context
* node
)
2024 (ref (lvar-uses (basic-combination-fun node
)))
2025 (args (basic-combination-args node
)))
2027 (unless (and (ref-p ref
) (constant-reference-p ref
)
2029 (return-from ir1-optimize-mv-call
))
2031 (multiple-value-bind (min max
)
2032 (fun-type-nargs (lvar-type fun
))
2034 (multiple-value-bind (types nvals
)
2035 (values-types (lvar-derived-type (first args
)))
2036 (declare (ignore types
))
2037 (if (eq nvals
:unknown
) nil nvals
))))
2040 (when (and min
(< total-nvals min
))
2042 "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
2045 (setf (basic-combination-kind node
) :error
)
2046 (return-from ir1-optimize-mv-call
))
2047 (when (and max
(> total-nvals max
))
2049 "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
2052 (setf (basic-combination-kind node
) :error
)
2053 (return-from ir1-optimize-mv-call
)))
2055 (let ((count (cond (total-nvals)
2056 ((and (policy node
(zerop verify-arg-count
))
2061 (with-ir1-environment-from-node node
2062 (let* ((dums (make-gensym-list count
))
2064 (leaf (ref-leaf ref
))
2065 (fun (ir1-convert-lambda
2066 `(lambda (&optional
,@dums
&rest
,ignore
)
2067 (declare (ignore ,ignore
))
2068 (%funcall
,leaf
,@dums
))
2069 :source-name
(leaf-%source-name leaf
)
2070 :debug-name
(leaf-%debug-name leaf
))))
2071 (change-ref-leaf ref fun
)
2072 (aver (eq (basic-combination-kind node
) :full
))
2073 (locall-analyze-component *current-component
*)
2074 (aver (eq (basic-combination-kind node
) :local
)))))))))
2078 ;;; (multiple-value-bind
2087 ;;; What we actually do is convert the VALUES combination into a
2088 ;;; normal LET combination calling the original :MV-LET lambda. If
2089 ;;; there are extra args to VALUES, discard the corresponding
2090 ;;; lvars. If there are insufficient args, insert references to NIL.
2091 (defun convert-mv-bind-to-let (call)
2092 (declare (type mv-combination call
))
2093 (let* ((arg (first (basic-combination-args call
)))
2094 (use (lvar-uses arg
)))
2095 (when (and (combination-p use
)
2096 (eq (lvar-fun-name (combination-fun use
))
2098 (let* ((fun (combination-lambda call
))
2099 (vars (lambda-vars fun
))
2100 (vals (combination-args use
))
2101 (nvars (length vars
))
2102 (nvals (length vals
)))
2103 (cond ((> nvals nvars
)
2104 (mapc #'flush-dest
(subseq vals nvars
))
2105 (setq vals
(subseq vals
0 nvars
)))
2107 (with-ir1-environment-from-node use
2108 (let ((node-prev (node-prev use
)))
2109 (setf (node-prev use
) nil
)
2110 (setf (ctran-next node-prev
) nil
)
2111 (collect ((res vals
))
2112 (loop for count below
(- nvars nvals
)
2113 for prev
= node-prev then ctran
2114 for ctran
= (make-ctran)
2115 and lvar
= (make-lvar use
)
2116 do
(reference-constant prev ctran lvar nil
)
2118 finally
(link-node-to-previous-ctran
2120 (setq vals
(res)))))))
2121 (setf (combination-args use
) vals
)
2122 (flush-dest (combination-fun use
))
2123 (let ((fun-lvar (basic-combination-fun call
)))
2124 (setf (lvar-dest fun-lvar
) use
)
2125 (setf (combination-fun use
) fun-lvar
)
2126 (flush-lvar-externally-checkable-type fun-lvar
))
2127 (setf (combination-kind use
) :local
)
2128 (setf (functional-kind fun
) :let
)
2129 (flush-dest (first (basic-combination-args call
)))
2132 (reoptimize-lvar (first vals
)))
2133 ;; Propagate derived types from the VALUES call to its args:
2134 ;; transforms can leave the VALUES call with a better type
2135 ;; than its args have, so make sure not to throw that away.
2136 (let ((types (values-type-types (node-derived-type use
))))
2139 (let ((type (pop types
)))
2140 (assert-lvar-type val type
**zero-typecheck-policy
**)))))
2141 ;; Propagate declared types of MV-BIND variables.
2142 (propagate-to-args use fun
)
2143 (reoptimize-call use
))
2147 ;;; (values-list (list x y z))
2152 ;;; In implementation, this is somewhat similar to
2153 ;;; CONVERT-MV-BIND-TO-LET. We grab the args of LIST and make them
2154 ;;; args of the VALUES-LIST call, flushing the old argument lvar
2155 ;;; (allowing the LIST to be flushed.)
2157 ;;; FIXME: Thus we lose possible type assertions on (LIST ...).
2158 (defoptimizer (values-list optimizer
) ((list) node
)
2159 (let ((use (lvar-uses list
)))
2160 (when (and (combination-p use
)
2161 (eq (lvar-fun-name (combination-fun use
))
2164 ;; FIXME: VALUES might not satisfy an assertion on NODE-LVAR.
2165 (change-ref-leaf (lvar-uses (combination-fun node
))
2166 (find-free-fun 'values
"in a strange place"))
2167 (setf (combination-kind node
) :full
)
2168 (let ((args (combination-args use
)))
2170 (setf (lvar-dest arg
) node
)
2171 (flush-lvar-externally-checkable-type arg
))
2172 (setf (combination-args use
) nil
)
2174 (flush-combination use
)
2175 (setf (combination-args node
) args
))
2178 ;;; If VALUES appears in a non-MV context, then effectively convert it
2179 ;;; to a PROG1. This allows the computation of the additional values
2180 ;;; to become dead code.
2181 (deftransform values
((&rest vals
) * * :node node
)
2182 (unless (lvar-single-value-p (node-lvar node
))
2183 (give-up-ir1-transform))
2184 (setf (node-derived-type node
)
2185 (make-short-values-type (list (single-value-type
2186 (node-derived-type node
)))))
2187 (principal-lvar-single-valuify (node-lvar node
))
2189 (let ((dummies (make-gensym-list (length (cdr vals
)))))
2190 `(lambda (val ,@dummies
)
2191 (declare (ignore ,@dummies
))
2197 (defun delete-cast (cast)
2198 (declare (type cast cast
))
2199 (let ((value (cast-value cast
))
2200 (lvar (node-lvar cast
)))
2201 (delete-filter cast lvar value
)
2203 (reoptimize-lvar lvar
)
2204 (when (lvar-single-value-p lvar
)
2205 (note-single-valuified-lvar lvar
)))
2208 (defun may-delete-vestigial-exit (cast)
2209 (let ((exit-lexenv (cast-vestigial-exit-lexenv cast
)))
2211 ;; Vestigial exits are only introduced when eliminating a local
2212 ;; RETURN-FROM. We may delete them only when we can show that
2213 ;; there are no other code paths that use the entry LVAR that
2214 ;; are live from within the block that contained the deleted
2215 ;; EXIT (our predecessor block). The conservative version of
2216 ;; this is that there are no EXITs for any ENTRY introduced
2217 ;; between the LEXENV of the deleted EXIT and the LEXENV of the
2219 (let* ((entry-lexenv (cast-vestigial-exit-entry-lexenv cast
))
2220 (entry-blocks (lexenv-blocks entry-lexenv
))
2221 (entry-tags (lexenv-tags entry-lexenv
)))
2222 (do ((current-block (lexenv-blocks exit-lexenv
) (cdr current-block
)))
2223 ((eq current-block entry-blocks
))
2224 (when (entry-exits (cadar current-block
))
2225 (return-from may-delete-vestigial-exit nil
)))
2226 (do ((current-tag (lexenv-tags exit-lexenv
) (cdr current-tag
)))
2227 ((eq current-tag entry-tags
))
2228 (when (entry-exits (cadar current-tag
))
2229 (return-from may-delete-vestigial-exit nil
))))))
2232 (defun compile-time-type-error-context (context)
2233 #+sb-xc-host context
2234 #-sb-xc-host
(source-to-string context
))
2236 (defun ir1-optimize-cast (cast &optional do-not-optimize
)
2237 (declare (type cast cast
))
2238 (let ((value (cast-value cast
))
2239 (atype (cast-asserted-type cast
)))
2240 (unless (or do-not-optimize
2241 (not (may-delete-vestigial-exit cast
)))
2242 (let ((lvar (node-lvar cast
)))
2243 (when (values-subtypep (lvar-derived-type value
)
2244 (cast-asserted-type cast
))
2246 (return-from ir1-optimize-cast t
))
2248 (when (and (listp (lvar-uses value
))
2250 ;; Pathwise removing of CAST
2251 (let ((ctran (node-next cast
))
2252 (dest (lvar-dest lvar
))
2255 (do-uses (use value
)
2256 (when (and (values-subtypep (node-derived-type use
) atype
)
2257 (immediately-used-p value use
))
2259 (when ctran
(ensure-block-start ctran
))
2260 (setq next-block
(first (block-succ (node-block cast
))))
2261 (ensure-block-start (node-prev cast
))
2262 (reoptimize-lvar lvar
)
2263 (setf (lvar-%derived-type value
) nil
))
2264 (%delete-lvar-use use
)
2265 (add-lvar-use use lvar
)
2266 (unlink-blocks (node-block use
) (node-block cast
))
2267 (link-blocks (node-block use
) next-block
)
2268 (when (and (return-p dest
)
2269 (basic-combination-p use
)
2270 (eq (basic-combination-kind use
) :local
))
2272 (dolist (use (merges))
2273 (merge-tail-sets use
)))))))
2275 (let* ((value-type (lvar-derived-type value
))
2276 (int (values-type-intersection value-type atype
)))
2277 (derive-node-type cast int
)
2278 (when (eq int
*empty-type
*)
2279 (unless (eq value-type
*empty-type
*)
2281 ;; FIXME: Do it in one step.
2282 (let ((context (node-source-form cast
))
2283 (detail (lvar-all-sources (cast-value cast
))))
2286 (if (cast-single-value-p cast
)
2288 `(multiple-value-call #'list
'dummy
)))
2291 ;; FIXME: Derived type.
2292 `(%compile-time-type-error
'dummy
2293 ',(type-specifier atype
)
2294 ',(type-specifier value-type
)
2296 ',(compile-time-type-error-context context
))))
2297 ;; KLUDGE: FILTER-LVAR does not work for non-returning
2298 ;; functions, so we declare the return type of
2299 ;; %COMPILE-TIME-TYPE-ERROR to be * and derive the real type
2301 (setq value
(cast-value cast
))
2302 (derive-node-type (lvar-uses value
) *empty-type
*)
2303 (maybe-terminate-block (lvar-uses value
) nil
)
2304 ;; FIXME: Is it necessary?
2305 (aver (null (block-pred (node-block cast
))))
2306 (delete-block-lazily (node-block cast
))
2307 (return-from ir1-optimize-cast
)))
2308 (when (eq (node-derived-type cast
) *empty-type
*)
2309 (maybe-terminate-block cast nil
))
2311 (when (and (cast-%type-check cast
)
2312 (values-subtypep value-type
2313 (cast-type-to-check cast
)))
2314 (setf (cast-%type-check cast
) nil
))))
2316 (unless do-not-optimize
2317 (setf (node-reoptimize cast
) nil
)))
2319 (deftransform make-symbol
((string) (simple-string))
2320 `(%make-symbol string
))