1 ;;;; structures for the first intermediate representation in the
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
15 ;;; The front-end data structure (IR1) is composed of nodes and
16 ;;; continuations. The general idea is that continuations contain
17 ;;; top-down information and nodes contain bottom-up, derived
18 ;;; information. A continuation represents a place in the code, while
19 ;;; a node represents code that does something.
21 ;;; This representation is more of a flow-graph than an augmented
22 ;;; syntax tree. The evaluation order is explicitly represented in the
23 ;;; linkage by continuations, rather than being implicit in the nodes
24 ;;; which receive the the results of evaluation. This allows us to
25 ;;; decouple the flow of results from the flow of control. A
26 ;;; continuation represents both, but the continuation can represent
27 ;;; the case of a discarded result by having no DEST.
29 (def!struct
(continuation
30 (:make-load-form-fun ignore-it
)
31 (:constructor make-continuation
(&optional dest
)))
32 ;; an indication of the way that this continuation is currently used
35 ;; A continuation for which all control-related slots have the
36 ;; default values. A continuation is unused during IR1 conversion
37 ;; until it is assigned a block, and may be also be temporarily
38 ;; unused during later manipulations of IR1. In a consistent
39 ;; state there should never be any mention of :UNUSED
40 ;; continuations. NEXT can have a non-null value if the next node
41 ;; has already been determined.
44 ;; A continuation that has been deleted from IR1. Any pointers into
45 ;; IR1 are cleared. There are two conditions under which a deleted
46 ;; continuation may appear in code:
47 ;; -- The CONT of the LAST node in a block may be a deleted
48 ;; continuation when the original receiver of the continuation's
49 ;; value was deleted. Note that DEST in a deleted continuation is
50 ;; null, so it is easy to know not to attempt delivering any
51 ;; values to the continuation.
52 ;; -- Unreachable code that hasn't been deleted yet may receive
53 ;; deleted continuations. All such code will be in blocks that
54 ;; have DELETE-P set. All unreachable code is deleted by control
55 ;; optimization, so the backend doesn't have to worry about this.
58 ;; The continuation that is the START of BLOCK. This is the only kind
59 ;; of continuation that can have more than one use. The BLOCK's
60 ;; START-USES is a list of all the uses.
62 ;; :DELETED-BLOCK-START
63 ;; Like :BLOCK-START, but BLOCK has been deleted. A block
64 ;; starting continuation is made into a deleted block start when
65 ;; the block is deleted, but the continuation still may have
66 ;; value semantics. Since there isn't any code left, next is
70 ;; A continuation that is the CONT of some node in BLOCK.
71 (kind :unused
:type
(member :unused
:deleted
:inside-block
:block-start
72 :deleted-block-start
))
73 ;; The node which receives this value, if any. In a deleted
74 ;; continuation, this is null even though the node that receives
75 ;; this continuation may not yet be deleted.
76 (dest nil
:type
(or node null
))
77 ;; If this is a NODE, then it is the node which is to be evaluated
78 ;; next. This is always null in :DELETED and :UNUSED continuations,
79 ;; and will be null in a :INSIDE-BLOCK continuation when this is the
81 (next nil
:type
(or node null
))
82 ;; an assertion on the type of this continuation's value
83 (asserted-type *wild-type
* :type ctype
)
84 ;; cached type of this continuation's value. If NIL, then this must
85 ;; be recomputed: see CONTINUATION-DERIVED-TYPE.
86 (%derived-type nil
:type
(or ctype null
))
87 ;; the node where this continuation is used, if unique. This is always
88 ;; null in :DELETED and :UNUSED continuations, and is never null in
89 ;; :INSIDE-BLOCK continuations. In a :BLOCK-START continuation, the
90 ;; BLOCK's START-USES indicate whether NIL means no uses or more
92 (use nil
:type
(or node null
))
93 ;; the basic block this continuation is in. This is null only in
94 ;; :DELETED and :UNUSED continuations. Note that blocks that are
95 ;; unreachable but still in the DFO may receive deleted
96 ;; continuations, so it isn't o.k. to assume that any continuation
97 ;; that you pick up out of its DEST node has a BLOCK.
98 (block nil
:type
(or cblock null
))
99 ;; set to true when something about this continuation's value has
100 ;; changed. See REOPTIMIZE-CONTINUATION. This provides a way for IR1
101 ;; optimize to determine which operands to a node have changed. If
102 ;; the optimizer for this node type doesn't care, it can elect not
103 ;; to clear this flag.
104 (reoptimize t
:type boolean
)
105 ;; an indication of what we have proven about how this contination's
106 ;; type assertion is satisfied:
109 ;; No type check is necessary (proven type is a subtype of the assertion.)
112 ;; A type check is needed.
115 ;; Don't do a type check, but believe (intersect) the assertion.
116 ;; A T check can be changed to :DELETED if we somehow prove the
117 ;; check is unnecessary, or if we eliminate it through a policy
121 ;; Type check generation sets the slot to this if a check is
122 ;; called for, but it believes it has proven that the check won't
123 ;; be done for policy reasons or because a safe implementation
124 ;; will be used. In the latter case, LTN must ensure that a safe
125 ;; implementation *is* used.
127 ;; This is computed lazily by CONTINUATION-DERIVED-TYPE, so use
128 ;; CONTINUATION-TYPE-CHECK instead of the %'ed slot accessor.
129 (%type-check t
:type
(member t nil
:deleted
:no-check
))
130 ;; Asserted type, weakend according to policies
131 (type-to-check *wild-type
* :type ctype
)
132 ;; Cached type which is checked by DEST. If NIL, then this must be
133 ;; recomputed: see CONTINUATION-EXTERNALLY-CHECKABLE-TYPE.
134 (%externally-checkable-type nil
:type
(or null ctype
))
135 ;; something or other that the back end annotates this continuation with
137 ;; uses of this continuation in the lexical environment. They are
138 ;; recorded so that when one continuation is substituted for another
139 ;; the environment may be updated properly.
140 (lexenv-uses nil
:type list
))
142 (def!method print-object
((x continuation
) stream
)
143 (print-unreadable-object (x stream
:type t
:identity t
)))
145 (defstruct (node (:constructor nil
)
147 ;; unique ID for debugging
148 #!+sb-show
(id (new-object-id) :read-only t
)
149 ;; the bottom-up derived type for this node. This does not take into
150 ;; consideration output type assertions on this node (actually on its CONT).
151 (derived-type *wild-type
* :type ctype
)
152 ;; True if this node needs to be optimized. This is set to true
153 ;; whenever something changes about the value of a continuation
154 ;; whose DEST is this node.
155 (reoptimize t
:type boolean
)
156 ;; the continuation which receives the value of this node. This also
157 ;; indicates what we do controlwise after evaluating this node. This
158 ;; may be null during IR1 conversion.
159 (cont nil
:type
(or continuation null
))
160 ;; the continuation that this node is the next of. This is null
161 ;; during IR1 conversion when we haven't linked the node in yet or
162 ;; in nodes that have been deleted from the IR1 by UNLINK-NODE.
163 (prev nil
:type
(or continuation null
))
164 ;; the lexical environment this node was converted in
165 (lexenv *lexenv
* :type lexenv
)
166 ;; a representation of the source code responsible for generating
169 ;; For a form introduced by compilation (does not appear in the
170 ;; original source), the path begins with a list of all the
171 ;; enclosing introduced forms. This list is from the inside out,
172 ;; with the form immediately responsible for this node at the head
175 ;; Following the introduced forms is a representation of the
176 ;; location of the enclosing original source form. This transition
177 ;; is indicated by the magic ORIGINAL-SOURCE-START marker. The first
178 ;; element of the original source is the "form number", which is the
179 ;; ordinal number of this form in a depth-first, left-to-right walk
180 ;; of the truly-top-level form in which this appears.
182 ;; Following is a list of integers describing the path taken through
183 ;; the source to get to this point:
184 ;; (K L M ...) => (NTH K (NTH L (NTH M ...)))
186 ;; The last element in the list is the top level form number, which
187 ;; is the ordinal number (in this call to the compiler) of the truly
188 ;; top level form containing the original source.
189 (source-path *current-path
* :type list
)
190 ;; If this node is in a tail-recursive position, then this is set to
191 ;; T. At the end of IR1 (in physical environment analysis) this is
192 ;; computed for all nodes (after cleanup code has been emitted).
193 ;; Before then, a non-null value indicates that IR1 optimization has
194 ;; converted a tail local call to a direct transfer.
196 ;; If the back-end breaks tail-recursion for some reason, then it
197 ;; can null out this slot.
198 (tail-p nil
:type boolean
))
200 ;;; Flags that are used to indicate various things about a block, such
201 ;;; as what optimizations need to be done on it:
202 ;;; -- REOPTIMIZE is set when something interesting happens the uses of a
203 ;;; continuation whose DEST is in this block. This indicates that the
204 ;;; value-driven (forward) IR1 optimizations should be done on this block.
205 ;;; -- FLUSH-P is set when code in this block becomes potentially flushable,
206 ;;; usually due to a continuation's DEST becoming null.
207 ;;; -- TYPE-CHECK is true when the type check phase should be run on this
208 ;;; block. IR1 optimize can introduce new blocks after type check has
209 ;;; already run. We need to check these blocks, but there is no point in
210 ;;; checking blocks we have already checked.
211 ;;; -- DELETE-P is true when this block is used to indicate that this block
212 ;;; has been determined to be unreachable and should be deleted. IR1
213 ;;; phases should not attempt to examine or modify blocks with DELETE-P
214 ;;; set, since they may:
215 ;;; - be in the process of being deleted, or
216 ;;; - have no successors, or
217 ;;; - receive :DELETED continuations.
218 ;;; -- TYPE-ASSERTED, TEST-MODIFIED
219 ;;; These flags are used to indicate that something in this block
220 ;;; might be of interest to constraint propagation. TYPE-ASSERTED
221 ;;; is set when a continuation type assertion is strengthened.
222 ;;; TEST-MODIFIED is set whenever the test for the ending IF has
223 ;;; changed (may be true when there is no IF.)
224 (!def-boolean-attribute block
225 reoptimize flush-p type-check delete-p type-asserted test-modified
)
227 ;;; FIXME: Tweak so that definitions of e.g. BLOCK-DELETE-P is
228 ;;; findable by grep for 'def.*block-delete-p'.
229 (macrolet ((frob (slot)
230 `(defmacro ,(symbolicate "BLOCK-" slot
) (block)
231 `(block-attributep (block-flags ,block
) ,',slot
))))
237 (frob test-modified
))
239 ;;; The CBLOCK structure represents a basic block. We include
240 ;;; SSET-ELEMENT so that we can have sets of blocks. Initially the
241 ;;; SSET-ELEMENT-NUMBER is null, DFO analysis numbers in reverse DFO.
242 ;;; During IR2 conversion, IR1 blocks are re-numbered in forward emit
243 ;;; order. This latter numbering also forms the basis of the block
244 ;;; numbering in the debug-info (though that is relative to the start
245 ;;; of the function.)
246 (defstruct (cblock (:include sset-element
)
247 (:constructor make-block
(start))
248 (:constructor make-block-key
)
251 (:copier copy-block
))
252 ;; a list of all the blocks that are predecessors/successors of this
253 ;; block. In well-formed IR1, most blocks will have one successor.
254 ;; The only exceptions are:
255 ;; 1. component head blocks (any number)
256 ;; 2. blocks ending in an IF (1 or 2)
257 ;; 3. blocks with DELETE-P set (zero)
258 (pred nil
:type list
)
259 (succ nil
:type list
)
260 ;; the continuation which heads this block (either a :BLOCK-START or
261 ;; :DELETED-BLOCK-START), or NIL when we haven't made the start
262 ;; continuation yet (and in the dummy component head and tail
264 (start nil
:type
(or continuation null
))
265 ;; a list of all the nodes that have START as their CONT
266 (start-uses nil
:type list
)
267 ;; the last node in this block. This is NIL when we are in the
268 ;; process of building a block (and in the dummy component head and
270 (last nil
:type
(or node null
))
271 ;; the forward and backward links in the depth-first ordering of the
272 ;; blocks. These slots are NIL at beginning/end.
273 (next nil
:type
(or null cblock
))
274 (prev nil
:type
(or null cblock
))
275 ;; This block's attributes: see above.
276 (flags (block-attributes reoptimize flush-p type-check type-asserted
279 ;; in constraint propagation: list of LAMBDA-VARs killed in this block
280 ;; in copy propagation: list of killed TNs
282 ;; other sets used in constraint propagation and/or copy propagation
286 ;; the component this block is in, or NIL temporarily during IR1
287 ;; conversion and in deleted blocks
289 (aver-live-component *current-component
*)
291 :type
(or component null
))
292 ;; a flag used by various graph-walking code to determine whether
293 ;; this block has been processed already or what. We make this
294 ;; initially NIL so that FIND-INITIAL-DFO doesn't have to scan the
295 ;; entire initial component just to clear the flags.
297 ;; some kind of info used by the back end
299 ;; constraints that hold in this block and its successors by merit
300 ;; of being tested by its IF predecessors.
301 (test-constraint nil
:type
(or sset null
)))
302 (def!method print-object
((cblock cblock
) stream
)
303 (print-unreadable-object (cblock stream
:type t
:identity t
)
304 (format stream
"~W :START c~W"
305 (block-number cblock
)
306 (cont-num (block-start cblock
)))))
308 ;;; The BLOCK-ANNOTATION class is inherited (via :INCLUDE) by
309 ;;; different BLOCK-INFO annotation structures so that code
310 ;;; (specifically control analysis) can be shared.
311 (defstruct (block-annotation (:constructor nil
)
313 ;; The IR1 block that this block is in the INFO for.
314 (block (missing-arg) :type cblock
)
315 ;; the next and previous block in emission order (not DFO). This
316 ;; determines which block we drop though to, and is also used to
317 ;; chain together overflow blocks that result from splitting of IR2
318 ;; blocks in lifetime analysis.
319 (next nil
:type
(or block-annotation null
))
320 (prev nil
:type
(or block-annotation null
)))
322 ;;; A COMPONENT structure provides a handle on a connected piece of
323 ;;; the flow graph. Most of the passes in the compiler operate on
324 ;;; COMPONENTs rather than on the entire flow graph.
326 ;;; According to the CMU CL internals/front.tex, the reason for
327 ;;; separating compilation into COMPONENTs is
328 ;;; to increase the efficiency of large block compilations. In
329 ;;; addition to improving locality of reference and reducing the
330 ;;; size of flow analysis problems, this allows back-end data
331 ;;; structures to be reclaimed after the compilation of each
333 (defstruct (component (:copier nil
))
334 ;; unique ID for debugging
335 #!+sb-show
(id (new-object-id) :read-only t
)
336 ;; the kind of component
338 ;; (The terminology here is left over from before
339 ;; sbcl-0.pre7.34.flaky5.2, when there was no such thing as
340 ;; FUNCTIONAL-HAS-EXTERNAL-REFERENCES-P, so that Python was
341 ;; incapable of building standalone :EXTERNAL functions, but instead
342 ;; had to implement things like #'CL:COMPILE as FUNCALL of a little
343 ;; toplevel stub whose sole purpose was to return an :EXTERNAL
346 ;; The possibilities are:
348 ;; an ordinary component, containing non-top-level code
350 ;; a component containing only load-time code
352 ;; In the old system, before FUNCTIONAL-HAS-EXTERNAL-REFERENCES-P
353 ;; was defined, this was necessarily a component containing both
354 ;; top level and run-time code. Now this state is also used for
355 ;; a component with HAS-EXTERNAL-REFERENCES-P functionals in it.
357 ;; the result of initial IR1 conversion, on which component
358 ;; analysis has not been done
360 ;; debris left over from component analysis
362 ;; See also COMPONENT-TOPLEVELISH-P.
363 (kind nil
:type
(member nil
:toplevel
:complex-toplevel
:initial
:deleted
))
364 ;; the blocks that are the dummy head and tail of the DFO
366 ;; Entry/exit points have these blocks as their
367 ;; predecessors/successors. Null temporarily. The start and return
368 ;; from each non-deleted function is linked to the component head
369 ;; and tail. Until physical environment analysis links NLX entry
370 ;; stubs to the component head, every successor of the head is a
371 ;; function start (i.e. begins with a BIND node.)
372 (head nil
:type
(or null cblock
))
373 (tail nil
:type
(or null cblock
))
374 ;; This becomes a list of the CLAMBDA structures for all functions
375 ;; in this component. OPTIONAL-DISPATCHes are represented only by
376 ;; their XEP and other associated lambdas. This doesn't contain any
377 ;; deleted or LET lambdas.
379 ;; Note that logical associations between CLAMBDAs and COMPONENTs
380 ;; seem to exist for a while before this is initialized. See e.g.
381 ;; the NEW-FUNCTIONALS slot. In particular, I got burned by writing
382 ;; some code to use this value to decide which components need
383 ;; LOCALL-ANALYZE-COMPONENT, when it turns out that
384 ;; LOCALL-ANALYZE-COMPONENT had a role in initializing this value
385 ;; (and DFO stuff does too, maybe). Also, even after it's
386 ;; initialized, it might change as CLAMBDAs are deleted or merged.
388 (lambdas () :type list
)
389 ;; a list of FUNCTIONALs for functions that are newly converted, and
390 ;; haven't been local-call analyzed yet. Initially functions are not
391 ;; in the LAMBDAS list. Local call analysis moves them there
392 ;; (possibly as LETs, or implicitly as XEPs if an OPTIONAL-DISPATCH.)
393 ;; Between runs of local call analysis there may be some debris of
394 ;; converted or even deleted functions in this list.
395 (new-functionals () :type list
)
396 ;; If this is true, then there is stuff in this component that could
397 ;; benefit from further IR1 optimization.
398 (reoptimize t
:type boolean
)
399 ;; If this is true, then the control flow in this component was
400 ;; messed up by IR1 optimizations, so the DFO should be recomputed.
401 (reanalyze nil
:type boolean
)
402 ;; some sort of name for the code in this component
403 (name "<unknown>" :type simple-string
)
404 ;; When I am a child, this is :NO-IR2-YET.
405 ;; In my adulthood, IR2 stores notes to itself here.
406 ;; After I have left the great wheel and am staring into the GC, this
407 ;; is set to :DEAD to indicate that it's a gruesome error to operate
408 ;; on me (e.g. by using me as *CURRENT-COMPONENT*, or by pushing
409 ;; LAMBDAs onto my NEW-FUNCTIONALS, as in sbcl-0.pre7.115).
410 (info :no-ir2-yet
:type
(or ir2-component
(member :no-ir2-yet
:dead
)))
411 ;; the SOURCE-INFO structure describing where this component was
413 (source-info *source-info
* :type source-info
)
414 ;; count of the number of inline expansions we have done while
415 ;; compiling this component, to detect infinite or exponential
417 (inline-expansions 0 :type index
)
418 ;; a map from combination nodes to things describing how an
419 ;; optimization of the node failed. The description is an alist
420 ;; (TRANSFORM . ARGS), where TRANSFORM is the structure describing
421 ;; the transform that failed, and ARGS is either a list of format
422 ;; arguments for the note, or the FUN-TYPE that would have
423 ;; enabled the transformation but failed to match.
424 (failed-optimizations (make-hash-table :test
'eq
) :type hash-table
)
425 ;; This is similar to NEW-FUNCTIONALS, but is used when a function
426 ;; has already been analyzed, but new references have been added by
427 ;; inline expansion. Unlike NEW-FUNCTIONALS, this is not disjoint
428 ;; from COMPONENT-LAMBDAS.
429 (reanalyze-functionals nil
:type list
))
430 (defprinter (component :identity t
)
433 (reanalyze :test reanalyze
))
435 ;;; Check that COMPONENT is suitable for roles which involve adding
436 ;;; new code. (gotta love imperative programming with lotso in-place
438 (defun aver-live-component (component)
439 ;; FIXME: As of sbcl-0.pre7.115, we're asserting that
440 ;; COMPILE-COMPONENT hasn't happened yet. Might it be even better
441 ;; (certainly stricter, possibly also correct...) to assert that
442 ;; IR1-FINALIZE hasn't happened yet?
443 (aver (not (eql (component-info component
) :dead
))))
445 ;;; Before sbcl-0.7.0, there were :TOPLEVEL things which were magical
446 ;;; in multiple ways. That's since been refactored into the orthogonal
447 ;;; properties "optimized for locall with no arguments" and "externally
448 ;;; visible/referenced (so don't delete it)". The code <0.7.0 did a lot
449 ;;; of tests a la (EQ KIND :TOP_LEVEL) in the "don't delete it?" sense;
450 ;;; this function is a sort of literal translation of those tests into
453 ;;; FIXME: After things settle down, bare :TOPLEVEL might go away, at
454 ;;; which time it might be possible to replace the COMPONENT-KIND
455 ;;; :TOPLEVEL mess with a flag COMPONENT-HAS-EXTERNAL-REFERENCES-P
456 ;;; along the lines of FUNCTIONAL-HAS-EXTERNAL-REFERENCES-P.
457 (defun lambda-toplevelish-p (clambda)
458 (or (eql (lambda-kind clambda
) :toplevel
)
459 (lambda-has-external-references-p clambda
)))
460 (defun component-toplevelish-p (component)
461 (member (component-kind component
)
462 '(:toplevel
:complex-toplevel
)))
464 ;;; A CLEANUP structure represents some dynamic binding action. Blocks
465 ;;; are annotated with the current CLEANUP so that dynamic bindings
466 ;;; can be removed when control is transferred out of the binding
467 ;;; environment. We arrange for changes in dynamic bindings to happen
468 ;;; at block boundaries, so that cleanup code may easily be inserted.
469 ;;; The "mess-up" action is explicitly represented by a funny function
470 ;;; call or ENTRY node.
472 ;;; We guarantee that CLEANUPs only need to be done at block boundaries
473 ;;; by requiring that the exit continuations initially head their
474 ;;; blocks, and then by not merging blocks when there is a cleanup
476 (defstruct (cleanup (:copier nil
))
477 ;; the kind of thing that has to be cleaned up
479 :type
(member :special-bind
:catch
:unwind-protect
:block
:tagbody
))
480 ;; the node that messes things up. This is the last node in the
481 ;; non-messed-up environment. Null only temporarily. This could be
482 ;; deleted due to unreachability.
483 (mess-up nil
:type
(or node null
))
484 ;; a list of all the NLX-INFO structures whose NLX-INFO-CLEANUP is
485 ;; this cleanup. This is filled in by physical environment analysis.
486 (nlx-info nil
:type list
))
487 (defprinter (cleanup :identity t
)
490 (nlx-info :test nlx-info
))
492 ;;; A PHYSENV represents the result of physical environment analysis.
494 ;;; As far as I can tell from reverse engineering, this IR1 structure
495 ;;; represents the physical environment (which is probably not the
496 ;;; standard Lispy term for this concept, but I dunno what is the
497 ;;; standard term): those things in the lexical environment which a
498 ;;; LAMBDA actually interacts with. Thus in
499 ;;; (DEFUN FROB-THINGS (THINGS)
500 ;;; (DOLIST (THING THINGS)
501 ;;; (BLOCK FROBBING-ONE-THING
502 ;;; (MAPCAR (LAMBDA (PATTERN)
503 ;;; (WHEN (FITS-P THING PATTERN)
504 ;;; (RETURN-FROM FROB-THINGS (LIST :FIT THING PATTERN))))
506 ;;; the variables THINGS, THING, and PATTERN and the block names
507 ;;; FROB-THINGS and FROBBING-ONE-THING are all in the inner LAMBDA's
508 ;;; lexical environment, but of those only THING, PATTERN, and
509 ;;; FROB-THINGS are in its physical environment. In IR1, we largely
510 ;;; just collect the names of these things; in IR2 an IR2-PHYSENV
511 ;;; structure is attached to INFO and used to keep track of
512 ;;; associations between these names and less-abstract things (like
513 ;;; TNs, or eventually stack slots and registers). -- WHN 2001-09-29
514 (defstruct (physenv (:copier nil
))
515 ;; the function that allocates this physical environment
516 (lambda (missing-arg) :type clambda
:read-only t
)
517 #|
; seems not to be used as of sbcl-0.pre7.51
518 ;; a list of all the lambdas that allocate variables in this
519 ;; physical environment
520 (lambdas nil
:type list
)
522 ;; This ultimately converges to a list of all the LAMBDA-VARs and
523 ;; NLX-INFOs needed from enclosing environments by code in this
524 ;; physical environment. In the meantime, it may be
525 ;; * NIL at object creation time
526 ;; * a superset of the correct result, generated somewhat later
527 ;; * smaller and smaller sets converging to the correct result as
528 ;; we notice and delete unused elements in the superset
529 (closure nil
:type list
)
530 ;; a list of NLX-INFO structures describing all the non-local exits
531 ;; into this physical environment
532 (nlx-info nil
:type list
)
533 ;; some kind of info used by the back end
535 (defprinter (physenv :identity t
)
537 (closure :test closure
)
538 (nlx-info :test nlx-info
))
540 ;;; An TAIL-SET structure is used to accumulate information about
541 ;;; tail-recursive local calls. The "tail set" is effectively the
542 ;;; transitive closure of the "is called tail-recursively by"
545 ;;; All functions in the same tail set share the same TAIL-SET
546 ;;; structure. Initially each function has its own TAIL-SET, but when
547 ;;; IR1-OPTIMIZE-RETURN notices a tail local call, it joins the tail
548 ;;; sets of the called function and the calling function.
550 ;;; The tail set is somewhat approximate, because it is too early to
551 ;;; be sure which calls will be tail-recursive. Any call that *might*
552 ;;; end up tail-recursive causes TAIL-SET merging.
553 (defstruct (tail-set)
554 ;; a list of all the LAMBDAs in this tail set
555 (funs nil
:type list
)
556 ;; our current best guess of the type returned by these functions.
557 ;; This is the union across all the functions of the return node's
558 ;; RESULT-TYPE, excluding local calls.
559 (type *wild-type
* :type ctype
)
560 ;; some info used by the back end
562 (defprinter (tail-set :identity t
)
567 ;;; An NLX-INFO structure is used to collect various information about
568 ;;; non-local exits. This is effectively an annotation on the
569 ;;; CONTINUATION, although it is accessed by searching in the
570 ;;; PHYSENV-NLX-INFO.
571 (def!struct
(nlx-info (:make-load-form-fun ignore-it
))
572 ;; the cleanup associated with this exit. In a catch or
573 ;; unwind-protect, this is the :CATCH or :UNWIND-PROTECT cleanup,
574 ;; and not the cleanup for the escape block. The CLEANUP-KIND of
575 ;; this thus provides a good indication of what kind of exit is
577 (cleanup (missing-arg) :type cleanup
)
578 ;; the continuation exited to (the CONT of the EXIT nodes). If this
579 ;; exit is from an escape function (CATCH or UNWIND-PROTECT), then
580 ;; physical environment analysis deletes the escape function and
581 ;; instead has the %NLX-ENTRY use this continuation.
583 ;; This slot is primarily an indication of where this exit delivers
584 ;; its values to (if any), but it is also used as a sort of name to
585 ;; allow us to find the NLX-INFO that corresponds to a given exit.
586 ;; For this purpose, the ENTRY must also be used to disambiguate,
587 ;; since exits to different places may deliver their result to the
588 ;; same continuation.
589 (continuation (missing-arg) :type continuation
)
590 ;; the entry stub inserted by physical environment analysis. This is
591 ;; a block containing a call to the %NLX-ENTRY funny function that
592 ;; has the original exit destination as its successor. Null only
594 (target nil
:type
(or cblock null
))
595 ;; some kind of info used by the back end
597 (defprinter (nlx-info :identity t
)
604 ;;; Variables, constants and functions are all represented by LEAF
605 ;;; structures. A reference to a LEAF is indicated by a REF node. This
606 ;;; allows us to easily substitute one for the other without actually
607 ;;; hacking the flow graph.
608 (def!struct
(leaf (:make-load-form-fun ignore-it
)
610 ;; unique ID for debugging
611 #!+sb-show
(id (new-object-id) :read-only t
)
612 ;; (For public access to this slot, use LEAF-SOURCE-NAME.)
614 ;; the name of LEAF as it appears in the source, e.g. 'FOO or '(SETF
615 ;; FOO) or 'N or '*Z*, or the special .ANONYMOUS. value if there's
616 ;; no name for this thing in the source (as can happen for
617 ;; FUNCTIONALs, e.g. for anonymous LAMBDAs or for functions for
618 ;; top-level forms; and can also happen for anonymous constants) or
619 ;; perhaps also if the match between the name and the thing is
620 ;; skewed enough (e.g. for macro functions or method functions) that
621 ;; we don't want to have that name affect compilation
623 ;; (We use .ANONYMOUS. here more or less the way we'd ordinarily use
624 ;; NIL, but we're afraid to use NIL because it's a symbol which could
625 ;; be the name of a leaf, if only the constant named NIL.)
627 ;; The value of this slot in can affect ordinary runtime behavior,
628 ;; e.g. of special variables and known functions, not just debugging.
630 ;; See also the LEAF-DEBUG-NAME function and the
631 ;; FUNCTIONAL-%DEBUG-NAME slot.
632 (%source-name
(missing-arg)
633 :type
(or symbol
(and cons
(satisfies legal-fun-name-p
)))
635 ;; the type which values of this leaf must have
636 (type *universal-type
* :type ctype
)
637 ;; where the TYPE information came from:
638 ;; :DECLARED, from a declaration.
639 ;; :ASSUMED, from uses of the object.
640 ;; :DEFINED, from examination of the definition.
641 ;; FIXME: This should be a named type. (LEAF-WHERE-FROM? Or
642 ;; perhaps just WHERE-FROM, since it's not just used in LEAF,
643 ;; but also in various DEFINE-INFO-TYPEs in globaldb.lisp,
644 ;; and very likely elsewhere too.)
645 (where-from :assumed
:type
(member :declared
:assumed
:defined
))
646 ;; list of the REF nodes for this leaf
648 ;; true if there was ever a REF or SET node for this leaf. This may
649 ;; be true when REFS and SETS are null, since code can be deleted.
650 (ever-used nil
:type boolean
)
651 ;; some kind of info used by the back end
654 ;;; LEAF name operations
656 ;;; KLUDGE: wants CLOS..
657 (defun leaf-has-source-name-p (leaf)
658 (not (eq (leaf-%source-name leaf
)
660 (defun leaf-source-name (leaf)
661 (aver (leaf-has-source-name-p leaf
))
662 (leaf-%source-name leaf
))
663 (defun leaf-debug-name (leaf)
664 (if (functional-p leaf
)
665 ;; FUNCTIONALs have additional %DEBUG-NAME behavior.
666 (functional-debug-name leaf
)
667 ;; Other objects just use their source name.
669 ;; (As of sbcl-0.pre7.85, there are a few non-FUNCTIONAL
670 ;; anonymous objects, (anonymous constants..) and those would
671 ;; fail here if we ever tried to get debug names from them, but
672 ;; it looks as though it's never interesting to get debug names
673 ;; from them, so it's moot. -- WHN)
674 (leaf-source-name leaf
)))
676 ;;; The CONSTANT structure is used to represent known constant values.
677 ;;; If NAME is not null, then it is the name of the named constant
678 ;;; which this leaf corresponds to, otherwise this is an anonymous
680 (def!struct
(constant (:include leaf
))
681 ;; the value of the constant
683 (defprinter (constant :identity t
)
684 (%source-name
:test %source-name
)
687 ;;; The BASIC-VAR structure represents information common to all
688 ;;; variables which don't correspond to known local functions.
689 (def!struct
(basic-var (:include leaf
)
691 ;; Lists of the set nodes for this variable.
692 (sets () :type list
))
694 ;;; The GLOBAL-VAR structure represents a value hung off of the symbol
696 (def!struct
(global-var (:include basic-var
))
697 ;; kind of variable described
699 :type
(member :special
:global-function
:global
)))
700 (defprinter (global-var :identity t
)
703 (type :test
(not (eq type
*universal-type
*)))
704 (where-from :test
(not (eq where-from
:assumed
)))
707 ;;; A DEFINED-FUN represents a function that is defined in the same
708 ;;; compilation block, or that has an inline expansion, or that has a
709 ;;; non-NIL INLINEP value. Whenever we change the INLINEP state (i.e.
710 ;;; an inline proclamation) we copy the structure so that former
711 ;;; INLINEP values are preserved.
712 (def!struct
(defined-fun (:include global-var
713 (where-from :defined
)
714 (kind :global-function
)))
715 ;; The values of INLINEP and INLINE-EXPANSION initialized from the
716 ;; global environment.
717 (inlinep nil
:type inlinep
)
718 (inline-expansion nil
:type
(or cons null
))
719 ;; the block-local definition of this function (either because it
720 ;; was semi-inline, or because it was defined in this block). If
721 ;; this function is not an entry point, then this may be deleted or
722 ;; LET-converted. Null if we haven't converted the expansion yet.
723 (functional nil
:type
(or functional null
)))
724 (defprinter (defined-fun :identity t
)
728 (functional :test functional
))
732 ;;; We default the WHERE-FROM and TYPE slots to :DEFINED and FUNCTION.
733 ;;; We don't normally manipulate function types for defined functions,
734 ;;; but if someone wants to know, an approximation is there.
735 (def!struct
(functional (:include leaf
736 (%source-name
'.anonymous.
)
737 (where-from :defined
)
738 (type (specifier-type 'function
))))
739 ;; (For public access to this slot, use LEAF-DEBUG-NAME.)
741 ;; the name of FUNCTIONAL for debugging purposes, or NIL if we
742 ;; should just let the SOURCE-NAME fall through
744 ;; Unlike the SOURCE-NAME slot, this slot's value should never
745 ;; affect ordinary code behavior, only debugging/diagnostic behavior.
747 ;; Ha. Ah, the starry-eyed idealism of the writer of the above
748 ;; paragraph. FUNCTION-LAMBDA-EXPRESSION's behaviour, as of
749 ;; sbcl-0.7.11.x, differs if the name of the a function is a string
750 ;; or not, as if it is a valid function name then it can look for an
753 ;; The value of this slot can be anything, except that it shouldn't
754 ;; be a legal function name, since otherwise debugging gets
755 ;; confusing. (If a legal function name is a good name for the
756 ;; function, it should be in %SOURCE-NAME, and then we shouldn't
757 ;; need a %DEBUG-NAME.) In SBCL as of 0.pre7.87, it's always a
758 ;; string unless it's NIL, since that's how CMU CL represented debug
759 ;; names. However, eventually I (WHN) think it we should start using
760 ;; list values instead, since they have much nicer print properties
761 ;; (abbreviation, skipping package prefixes when unneeded, and
762 ;; renaming package prefixes when we do things like renaming SB!EXT
765 ;; E.g. for the function which implements (DEFUN FOO ...), we could
769 ;; for the function which implements the top level form
770 ;; (IN-PACKAGE :FOO) we could have
772 ;; %DEBUG-NAME="top level form (IN-PACKAGE :FOO)"
773 ;; for the function which implements FOO in
774 ;; (DEFUN BAR (...) (FLET ((FOO (...) ...)) ...))
777 ;; %DEBUG-NAME="FLET FOO in BAR"
778 ;; and for the function which implements FOO in
779 ;; (DEFMACRO FOO (...) ...)
781 ;; %SOURCE-NAME=FOO (or maybe .ANONYMOUS.?)
782 ;; %DEBUG-NAME="DEFMACRO FOO"
784 :type
(or null
(not (satisfies legal-fun-name-p
)))
786 ;; some information about how this function is used. These values
790 ;; an ordinary function, callable using local call
793 ;; a lambda that is used in only one local call, and has in
794 ;; effect been substituted directly inline. The return node is
795 ;; deleted, and the result is computed with the actual result
796 ;; continuation for the call.
799 ;; Similar to :LET (as per FUNCTIONAL-LETLIKE-P), but the call
803 ;; similar to a LET (as per FUNCTIONAL-SOMEWHAT-LETLIKE-P), but
804 ;; can have other than one call as long as there is at most
805 ;; one non-tail call.
808 ;; a lambda that is an entry point for an OPTIONAL-DISPATCH.
809 ;; Similar to NIL, but requires greater caution, since local call
810 ;; analysis may create new references to this function. Also, the
811 ;; function cannot be deleted even if it has *no* references. The
812 ;; OPTIONAL-DISPATCH is in the LAMDBA-OPTIONAL-DISPATCH.
815 ;; an external entry point lambda. The function it is an entry
816 ;; for is in the ENTRY-FUN slot.
819 ;; a top level lambda, holding a compiled top level form.
820 ;; Compiled very much like NIL, but provides an indication of
821 ;; top level context. A :TOPLEVEL lambda should have *no*
822 ;; references. Its ENTRY-FUN is a self-pointer.
825 ;; After a component is compiled, we clobber any top level code
826 ;; references to its non-closure XEPs with dummy FUNCTIONAL
827 ;; structures having this kind. This prevents the retained
828 ;; top level code from holding onto the IR for the code it
833 ;; special functions used internally by CATCH and UNWIND-PROTECT.
834 ;; These are pretty much like a normal function (NIL), but are
835 ;; treated specially by local call analysis and stuff. Neither
836 ;; kind should ever be given an XEP even though they appear as
837 ;; args to funny functions. An :ESCAPE function is never actually
838 ;; called, and thus doesn't need to have code generated for it.
841 ;; This function has been found to be uncallable, and has been
842 ;; marked for deletion.
843 (kind nil
:type
(member nil
:optional
:deleted
:external
:toplevel
844 :escape
:cleanup
:let
:mv-let
:assignment
846 ;; Is this a function that some external entity (e.g. the fasl dumper)
847 ;; refers to, so that even when it appears to have no references, it
848 ;; shouldn't be deleted? In the old days (before
849 ;; sbcl-0.pre7.37.flaky5.2) this was sort of implicitly true when
850 ;; KIND was :TOPLEVEL. Now it must be set explicitly, both for
851 ;; :TOPLEVEL functions and for any other kind of functions that we
852 ;; want to dump or return from #'CL:COMPILE or whatever.
853 (has-external-references-p nil
)
854 ;; In a normal function, this is the external entry point (XEP)
855 ;; lambda for this function, if any. Each function that is used
856 ;; other than in a local call has an XEP, and all of the
857 ;; non-local-call references are replaced with references to the
860 ;; In an XEP lambda (indicated by the :EXTERNAL kind), this is the
861 ;; function that the XEP is an entry-point for. The body contains
862 ;; local calls to all the actual entry points in the function. In a
863 ;; :TOPLEVEL lambda (which is its own XEP) this is a self-pointer.
865 ;; With all other kinds, this is null.
866 (entry-fun nil
:type
(or functional null
))
867 ;; the value of any inline/notinline declaration for a local
868 ;; function (or NIL in any case if no inline expansion is available)
869 (inlinep nil
:type inlinep
)
870 ;; If we have a lambda that can be used as in inline expansion for
871 ;; this function, then this is it. If there is no source-level
872 ;; lambda corresponding to this function then this is null (but then
873 ;; INLINEP will always be NIL as well.)
874 (inline-expansion nil
:type list
)
875 ;; the lexical environment that the INLINE-EXPANSION should be converted in
876 (lexenv *lexenv
* :type lexenv
)
877 ;; the original function or macro lambda list, or :UNSPECIFIED if
878 ;; this is a compiler created function
879 (arg-documentation nil
:type
(or list
(member :unspecified
)))
880 ;; various rare miscellaneous info that drives code generation & stuff
881 (plist () :type list
))
882 (defprinter (functional :identity t
)
887 ;;; Is FUNCTIONAL LET-converted? (where we're indifferent to whether
888 ;;; it returns one value or multiple values)
889 (defun functional-letlike-p (functional)
890 (member (functional-kind functional
)
893 ;;; Is FUNCTIONAL sorta LET-converted? (where even an :ASSIGNMENT counts)
895 ;;; FIXME: I (WHN) don't understand this one well enough to give a good
896 ;;; definition or even a good function name, it's just a literal copy
897 ;;; of a CMU CL idiom. Does anyone have a better name or explanation?
898 (defun functional-somewhat-letlike-p (functional)
899 (or (functional-letlike-p functional
)
900 (eql (functional-kind functional
) :assignment
)))
902 ;;; FUNCTIONAL name operations
903 (defun functional-debug-name (functional)
904 ;; FUNCTIONAL-%DEBUG-NAME takes precedence over FUNCTIONAL-SOURCE-NAME
905 ;; here because we want different debug names for the functions in
906 ;; DEFUN FOO and FLET FOO even though they have the same source name.
907 (or (functional-%debug-name functional
)
908 ;; Note that this will cause an error if the function is
909 ;; anonymous. In SBCL (as opposed to CMU CL) we make all
910 ;; FUNCTIONALs have debug names. The CMU CL code didn't bother
911 ;; in many FUNCTIONALs, especially those which were likely to be
912 ;; optimized away before the user saw them. However, getting
913 ;; that right requires a global understanding of the code,
914 ;; which seems bad, so we just require names for everything.
915 (leaf-source-name functional
)))
917 ;;; The CLAMBDA only deals with required lexical arguments. Special,
918 ;;; optional, keyword and rest arguments are handled by transforming
919 ;;; into simpler stuff.
920 (def!struct
(clambda (:include functional
)
922 (:predicate lambda-p
)
923 (:constructor make-lambda
)
924 (:copier copy-lambda
))
925 ;; list of LAMBDA-VAR descriptors for arguments
926 (vars nil
:type list
:read-only t
)
927 ;; If this function was ever a :OPTIONAL function (an entry-point
928 ;; for an OPTIONAL-DISPATCH), then this is that OPTIONAL-DISPATCH.
929 ;; The optional dispatch will be :DELETED if this function is no
931 (optional-dispatch nil
:type
(or optional-dispatch null
))
932 ;; the BIND node for this LAMBDA. This node marks the beginning of
933 ;; the lambda, and serves to explicitly represent the lambda binding
934 ;; semantics within the flow graph representation. This is null in
935 ;; deleted functions, and also in LETs where we deleted the call and
936 ;; bind (because there are no variables left), but have not yet
937 ;; actually deleted the LAMBDA yet.
938 (bind nil
:type
(or bind null
))
939 ;; the RETURN node for this LAMBDA, or NIL if it has been deleted.
940 ;; This marks the end of the lambda, receiving the result of the
941 ;; body. In a LET, the return node is deleted, and the body delivers
942 ;; the value to the actual continuation. The return may also be
943 ;; deleted if it is unreachable.
944 (return nil
:type
(or creturn null
))
945 ;; If this CLAMBDA is a LET, then this slot holds the LAMBDA whose
946 ;; LETS list we are in, otherwise it is a self-pointer.
947 (home nil
:type
(or clambda null
))
948 ;; all the lambdas that have been LET-substituted in this lambda.
949 ;; This is only non-null in lambdas that aren't LETs.
950 (lets nil
:type list
)
951 ;; all the ENTRY nodes in this function and its LETs, or null in a LET
952 (entries nil
:type list
)
953 ;; CLAMBDAs which are locally called by this lambda, and other
954 ;; objects (closed-over LAMBDA-VARs and XEPs) which this lambda
955 ;; depends on in such a way that DFO shouldn't put them in separate
957 (calls-or-closes nil
:type list
)
958 ;; the TAIL-SET that this LAMBDA is in. This is null during creation.
960 ;; In CMU CL, and old SBCL, this was also NILed out when LET
961 ;; conversion happened. That caused some problems, so as of
962 ;; sbcl-0.pre7.37.flaky5.2 when I was trying to get the compiler to
963 ;; emit :EXTERNAL functions directly, and so now the value
964 ;; is no longer NILed out in LET conversion, but instead copied
965 ;; (so that any further optimizations on the rest of the tail
966 ;; set won't modify the value) if necessary.
967 (tail-set nil
:type
(or tail-set null
))
968 ;; the structure which represents the phsical environment that this
969 ;; function's variables are allocated in. This is filled in by
970 ;; physical environment analysis. In a LET, this is EQ to our home's
971 ;; physical environment.
972 (physenv nil
:type
(or physenv null
))
973 ;; In a LET, this is the NODE-LEXENV of the combination node. We
974 ;; retain it so that if the LET is deleted (due to a lack of vars),
975 ;; we will still have caller's lexenv to figure out which cleanup is
977 (call-lexenv nil
:type
(or lexenv null
)))
978 (defprinter (clambda :conc-name lambda-
:identity t
)
982 (type :test
(not (eq type
*universal-type
*)))
983 (where-from :test
(not (eq where-from
:assumed
)))
984 (vars :prin1
(mapcar #'leaf-source-name vars
)))
986 ;;; The OPTIONAL-DISPATCH leaf is used to represent hairy lambdas. It
987 ;;; is a FUNCTIONAL, like LAMBDA. Each legal number of arguments has a
988 ;;; function which is called when that number of arguments is passed.
989 ;;; The function is called with all the arguments actually passed. If
990 ;;; additional arguments are legal, then the LEXPR style MORE-ENTRY
991 ;;; handles them. The value returned by the function is the value
992 ;;; which results from calling the OPTIONAL-DISPATCH.
994 ;;; The theory is that each entry-point function calls the next entry
995 ;;; point tail-recursively, passing all the arguments passed in and
996 ;;; the default for the argument the entry point is for. The last
997 ;;; entry point calls the real body of the function. In the presence
998 ;;; of SUPPLIED-P args and other hair, things are more complicated. In
999 ;;; general, there is a distinct internal function that takes the
1000 ;;; SUPPLIED-P args as parameters. The preceding entry point calls
1001 ;;; this function with NIL filled in for the SUPPLIED-P args, while
1002 ;;; the current entry point calls it with T in the SUPPLIED-P
1005 ;;; Note that it is easy to turn a call with a known number of
1006 ;;; arguments into a direct call to the appropriate entry-point
1007 ;;; function, so functions that are compiled together can avoid doing
1009 (def!struct
(optional-dispatch (:include functional
))
1010 ;; the original parsed argument list, for anyone who cares
1011 (arglist nil
:type list
)
1012 ;; true if &ALLOW-OTHER-KEYS was supplied
1013 (allowp nil
:type boolean
)
1014 ;; true if &KEY was specified (which doesn't necessarily mean that
1015 ;; there are any &KEY arguments..)
1016 (keyp nil
:type boolean
)
1017 ;; the number of required arguments. This is the smallest legal
1018 ;; number of arguments.
1019 (min-args 0 :type unsigned-byte
)
1020 ;; the total number of required and optional arguments. Args at
1021 ;; positions >= to this are &REST, &KEY or illegal args.
1022 (max-args 0 :type unsigned-byte
)
1023 ;; list of the LAMBDAs which are the entry points for non-rest,
1024 ;; non-key calls. The entry for MIN-ARGS is first, MIN-ARGS+1
1025 ;; second, ... MAX-ARGS last. The last entry-point always calls the
1026 ;; main entry; in simple cases it may be the main entry.
1027 (entry-points nil
:type list
)
1028 ;; an entry point which takes MAX-ARGS fixed arguments followed by
1029 ;; an argument context pointer and an argument count. This entry
1030 ;; point deals with listifying rest args and parsing keywords. This
1031 ;; is null when extra arguments aren't legal.
1032 (more-entry nil
:type
(or clambda null
))
1033 ;; the main entry-point into the function, which takes all arguments
1034 ;; including keywords as fixed arguments. The format of the
1035 ;; arguments must be determined by examining the arglist. This may
1036 ;; be used by callers that supply at least MAX-ARGS arguments and
1037 ;; know what they are doing.
1038 (main-entry nil
:type
(or clambda null
)))
1039 (defprinter (optional-dispatch :identity t
)
1043 (type :test
(not (eq type
*universal-type
*)))
1044 (where-from :test
(not (eq where-from
:assumed
)))
1050 (entry-points :test entry-points
)
1051 (more-entry :test more-entry
)
1054 ;;; The ARG-INFO structure allows us to tack various information onto
1055 ;;; LAMBDA-VARs during IR1 conversion. If we use one of these things,
1056 ;;; then the var will have to be massaged a bit before it is simple
1058 (def!struct arg-info
1059 ;; true if this arg is to be specially bound
1060 (specialp nil
:type boolean
)
1061 ;; the kind of argument being described. Required args only have arg
1062 ;; info structures if they are special.
1064 :type
(member :required
:optional
:keyword
:rest
1065 :more-context
:more-count
))
1066 ;; If true, this is the VAR for SUPPLIED-P variable of a keyword or
1067 ;; optional arg. This is true for keywords with non-constant
1068 ;; defaults even when there is no user-specified supplied-p var.
1069 (supplied-p nil
:type
(or lambda-var null
))
1070 ;; the default for a keyword or optional, represented as the
1071 ;; original Lisp code. This is set to NIL in &KEY arguments that are
1072 ;; defaulted using the SUPPLIED-P arg.
1073 (default nil
:type t
)
1074 ;; the actual key for a &KEY argument. Note that in ANSI CL this is
1075 ;; not necessarily a keyword: (DEFUN FOO (&KEY ((BAR BAR))) ...).
1076 (key nil
:type symbol
))
1077 (defprinter (arg-info :identity t
)
1078 (specialp :test specialp
)
1080 (supplied-p :test supplied-p
)
1081 (default :test default
)
1084 ;;; The LAMBDA-VAR structure represents a lexical lambda variable.
1085 ;;; This structure is also used during IR1 conversion to describe
1086 ;;; lambda arguments which may ultimately turn out not to be simple
1089 ;;; LAMBDA-VARs with no REFs are considered to be deleted; physical
1090 ;;; environment analysis isn't done on these variables, so the back
1091 ;;; end must check for and ignore unreferenced variables. Note that a
1092 ;;; deleted LAMBDA-VAR may have sets; in this case the back end is
1093 ;;; still responsible for propagating the SET-VALUE to the set's CONT.
1094 (def!struct
(lambda-var (:include basic-var
))
1095 ;; true if this variable has been declared IGNORE
1096 (ignorep nil
:type boolean
)
1097 ;; the CLAMBDA that this var belongs to. This may be null when we are
1098 ;; building a lambda during IR1 conversion.
1099 (home nil
:type
(or null clambda
))
1100 ;; This is set by physical environment analysis if it chooses an
1101 ;; indirect (value cell) representation for this variable because it
1102 ;; is both set and closed over.
1103 (indirect nil
:type boolean
)
1104 ;; The following two slots are only meaningful during IR1 conversion
1105 ;; of hairy lambda vars:
1107 ;; The ARG-INFO structure which holds information obtained from
1108 ;; &keyword parsing.
1109 (arg-info nil
:type
(or arg-info null
))
1110 ;; if true, the GLOBAL-VAR structure for the special variable which
1111 ;; is to be bound to the value of this argument
1112 (specvar nil
:type
(or global-var null
))
1113 ;; Set of the CONSTRAINTs on this variable. Used by constraint
1114 ;; propagation. This is left null by the lambda pre-pass if it
1115 ;; determine that this is a set closure variable, and is thus not a
1116 ;; good subject for flow analysis.
1117 (constraints nil
:type
(or sset null
)))
1118 (defprinter (lambda-var :identity t
)
1121 (type :test
(not (eq type
*universal-type
*)))
1122 (where-from :test
(not (eq where-from
:assumed
)))
1123 (ignorep :test ignorep
)
1124 (arg-info :test arg-info
)
1125 (specvar :test specvar
))
1127 ;;;; basic node types
1129 ;;; A REF represents a reference to a LEAF. REF-REOPTIMIZE is
1130 ;;; initially (and forever) NIL, since REFs don't receive any values
1131 ;;; and don't have any IR1 optimizer.
1132 (defstruct (ref (:include node
(reoptimize nil
))
1133 (:constructor make-ref
(derived-type leaf
))
1135 ;; The leaf referenced.
1136 (leaf nil
:type leaf
))
1137 (defprinter (ref :identity t
)
1141 ;;; Naturally, the IF node always appears at the end of a block.
1142 ;;; NODE-CONT is a dummy continuation, and is there only to keep
1144 (defstruct (cif (:include node
)
1147 (:constructor make-if
)
1149 ;; CONTINUATION for the predicate
1150 (test (missing-arg) :type continuation
)
1151 ;; the blocks that we execute next in true and false case,
1152 ;; respectively (may be the same)
1153 (consequent (missing-arg) :type cblock
)
1154 (alternative (missing-arg) :type cblock
))
1155 (defprinter (cif :conc-name if-
:identity t
)
1156 (test :prin1
(continuation-use test
))
1160 (defstruct (cset (:include node
1161 (derived-type *universal-type
*))
1164 (:constructor make-set
)
1166 ;; descriptor for the variable set
1167 (var (missing-arg) :type basic-var
)
1168 ;; continuation for the value form
1169 (value (missing-arg) :type continuation
))
1170 (defprinter (cset :conc-name set-
:identity t
)
1172 (value :prin1
(continuation-use value
)))
1174 ;;; The BASIC-COMBINATION structure is used to represent both normal
1175 ;;; and multiple value combinations. In a local function call, this
1176 ;;; node appears at the end of its block and the body of the called
1177 ;;; function appears as the successor. The NODE-CONT remains the
1178 ;;; continuation which receives the value of the call.
1179 (defstruct (basic-combination (:include node
)
1182 ;; continuation for the function
1183 (fun (missing-arg) :type continuation
)
1184 ;; list of CONTINUATIONs for the args. In a local call, an argument
1185 ;; continuation may be replaced with NIL to indicate that the
1186 ;; corresponding variable is unreferenced, and thus no argument
1187 ;; value need be passed.
1188 (args nil
:type list
)
1189 ;; the kind of function call being made. :LOCAL means that this is a
1190 ;; local call to a function in the same component, and that argument
1191 ;; syntax checking has been done, etc. Calls to known global
1192 ;; functions are represented by storing the FUN-INFO for the
1193 ;; function in this slot. :FULL is a call to an (as yet) unknown
1194 ;; function. :ERROR is like :FULL, but means that we have discovered
1195 ;; that the call contains an error, and should not be reconsidered
1196 ;; for optimization.
1197 (kind :full
:type
(or (member :local
:full
:error
) fun-info
))
1198 ;; some kind of information attached to this node by the back end
1201 ;;; The COMBINATION node represents all normal function calls,
1202 ;;; including FUNCALL. This is distinct from BASIC-COMBINATION so that
1203 ;;; an MV-COMBINATION isn't COMBINATION-P.
1204 (defstruct (combination (:include basic-combination
)
1205 (:constructor make-combination
(fun))
1207 (defprinter (combination :identity t
)
1209 (fun :prin1
(continuation-use fun
))
1210 (args :prin1
(mapcar (lambda (x)
1212 (continuation-use x
)
1216 ;;; An MV-COMBINATION is to MULTIPLE-VALUE-CALL as a COMBINATION is to
1217 ;;; FUNCALL. This is used to implement all the multiple-value
1218 ;;; receiving forms.
1219 (defstruct (mv-combination (:include basic-combination
)
1220 (:constructor make-mv-combination
(fun))
1222 (defprinter (mv-combination)
1223 (fun :prin1
(continuation-use fun
))
1224 (args :prin1
(mapcar #'continuation-use args
)))
1226 ;;; The BIND node marks the beginning of a lambda body and represents
1227 ;;; the creation and initialization of the variables.
1228 (defstruct (bind (:include node
)
1230 ;; the lambda we are binding variables for. Null when we are
1231 ;; creating the LAMBDA during IR1 translation.
1232 (lambda nil
:type
(or clambda null
)))
1236 ;;; The RETURN node marks the end of a lambda body. It collects the
1237 ;;; return values and represents the control transfer on return. This
1238 ;;; is also where we stick information used for TAIL-SET type
1240 (defstruct (creturn (:include node
)
1241 (:conc-name return-
)
1242 (:predicate return-p
)
1243 (:constructor make-return
)
1244 (:copier copy-return
))
1245 ;; the lambda we are returning from. Null temporarily during
1247 (lambda nil
:type
(or clambda null
))
1248 ;; the continuation which yields the value of the lambda
1249 (result (missing-arg) :type continuation
)
1250 ;; the union of the node-derived-type of all uses of the result
1251 ;; other than by a local call, intersected with the result's
1252 ;; asserted-type. If there are no non-call uses, this is
1254 (result-type *wild-type
* :type ctype
))
1255 (defprinter (creturn :conc-name return-
:identity t
)
1259 ;;;; non-local exit support
1261 ;;;; In IR1, we insert special nodes to mark potentially non-local
1264 ;;; The ENTRY node serves to mark the start of the dynamic extent of a
1265 ;;; lexical exit. It is the mess-up node for the corresponding :ENTRY
1267 (defstruct (entry (:include node
)
1269 ;; All of the EXIT nodes for potential non-local exits to this point.
1270 (exits nil
:type list
)
1271 ;; The cleanup for this entry. NULL only temporarily.
1272 (cleanup nil
:type
(or cleanup null
)))
1273 (defprinter (entry :identity t
)
1276 ;;; The EXIT node marks the place at which exit code would be emitted,
1277 ;;; if necessary. This is interposed between the uses of the exit
1278 ;;; continuation and the exit continuation's DEST. Instead of using
1279 ;;; the returned value being delivered directly to the exit
1280 ;;; continuation, it is delivered to our VALUE continuation. The
1281 ;;; original exit continuation is the exit node's CONT.
1282 (defstruct (exit (:include node
)
1284 ;; the ENTRY node that this is an exit for. If null, this is a
1285 ;; degenerate exit. A degenerate exit is used to "fill" an empty
1286 ;; block (which isn't allowed in IR1.) In a degenerate exit, Value
1287 ;; is always also null.
1288 (entry nil
:type
(or entry null
))
1289 ;; the continuation yielding the value we are to exit with. If NIL,
1290 ;; then no value is desired (as in GO).
1291 (value nil
:type
(or continuation null
)))
1292 (defprinter (exit :identity t
)
1295 (value :test value
))
1297 ;;;; miscellaneous IR1 structures
1299 (defstruct (undefined-warning
1300 #-no-ansi-print-object
1301 (:print-object
(lambda (x s
)
1302 (print-unreadable-object (x s
:type t
)
1303 (prin1 (undefined-warning-name x
) s
))))
1305 ;; the name of the unknown thing
1306 (name nil
:type
(or symbol list
))
1307 ;; the kind of reference to NAME
1308 (kind (missing-arg) :type
(member :function
:type
:variable
))
1309 ;; the number of times this thing was used
1310 (count 0 :type unsigned-byte
)
1311 ;; a list of COMPILER-ERROR-CONTEXT structures describing places
1312 ;; where this thing was used. Note that we only record the first
1313 ;; *UNDEFINED-WARNING-LIMIT* calls.
1314 (warnings () :type list
))
1316 ;;; a helper for the POLICY macro, defined late here so that the
1317 ;;; various type tests can be inlined
1318 (declaim (ftype (function ((or list lexenv node functional
)) list
)
1320 (defun %coerce-to-policy
(thing)
1321 (let ((result (etypecase thing
1323 (lexenv (lexenv-policy thing
))
1324 (node (lexenv-policy (node-lexenv thing
)))
1325 (functional (lexenv-policy (functional-lexenv thing
))))))
1326 ;; Test the first element of the list as a rudimentary sanity
1327 ;; that it really does look like a valid policy.
1328 (aver (or (null result
) (policy-quality-name-p (caar result
))))
1332 ;;;; Freeze some structure types to speed type testing.
1335 (declaim (freeze-type node leaf lexenv continuation cblock component cleanup
1336 physenv tail-set nlx-info
))