1 ;;;; structures for the second (virtual machine) intermediate
2 ;;;; representation in the compiler, IR2
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 largest number of TNs whose liveness changes that we can have
17 (defconstant local-tn-limit 64)
19 (deftype local-tn-number () `(integer 0 (,local-tn-limit)))
20 (deftype local-tn-count () `(integer 0 ,local-tn-limit))
21 (deftype local-tn-vector () `(simple-vector ,local-tn-limit))
22 (deftype local-tn-bit-vector () `(simple-bit-vector ,local-tn-limit))
24 ;;; Type of an SC number.
25 (deftype sc-number () `(integer 0 (,sc-number-limit)))
27 ;;; Types for vectors indexed by SC numbers.
28 (deftype sc-vector () `(simple-vector ,sc-number-limit))
29 (deftype sc-bit-vector () `(simple-bit-vector ,sc-number-limit))
31 ;;; The different policies we can use to determine the coding strategy.
33 '(member :safe :small :fast :fast-safe))
37 ;;; The primitive type is used to represent the aspects of type interesting
38 ;;; to the VM. Selection of IR2 translation templates is done on the basis of
39 ;;; the primitive types of the operands, and the primitive type of a value
40 ;;; is used to constrain the possible representations of that value.
41 (defstruct primitive-type
42 ;; The name of this primitive-type.
43 (name nil :type symbol)
44 ;; A list the SC numbers for all the SCs that a TN of this type can be
47 ;; The Lisp type equivalent to this type. If this type could never be
48 ;; returned by Primitive-Type, then this is the NIL (or empty) type.
49 (type (required-argument) :type ctype)
50 ;; The template used to check that an object is of this type. This is a
51 ;; template of one argument and one result, both of primitive-type T. If
52 ;; the argument is of the correct type, then it is delivered into the
53 ;; result. If the type is incorrect, then an error is signalled.
54 (check nil :type (or template null)))
56 (defprinter (primitive-type)
59 ;;;; IR1 annotations used for IR2 conversion
62 ;;; Holds the IR2-Block structure. If there are overflow blocks, then this
63 ;;; points to the first IR2-Block. The Block-Info of the dummy component
64 ;;; head and tail are dummy IR2 blocks that begin and end the emission order
68 ;;; Holds the IR2-Component structure.
71 ;;; Holds the IR2-Continuation structure. Continuations whose values aren't
72 ;;; used won't have any.
75 ;;; If non-null, then a TN in which the affected dynamic environment pointer
76 ;;; should be saved after the binding is instantiated.
79 ;;; Holds the IR2-Environment structure.
82 ;;; Holds the Return-Info structure.
85 ;;; Holds the IR2-NLX-Info structure.
88 ;;; If a non-set lexical variable, the TN that holds the value in the home
89 ;;; environment. If a constant, then the corresponding constant TN.
90 ;;; If an XEP lambda, then the corresponding Entry-Info structure.
92 ;;; Basic-Combination-Info
93 ;;; The template chosen by LTN, or
94 ;;; :FULL if this is definitely a full call.
95 ;;; :FUNNY if this is an oddball thing with IR2-convert.
96 ;;; :LOCAL if this is a local call.
99 ;;; After LTN analysis, this is true only in combination nodes that are
100 ;;; truly tail recursive.
102 ;;; The IR2-Block structure holds information about a block that is used during
103 ;;; and after IR2 conversion. It is stored in the Block-Info slot for the
104 ;;; associated block.
105 (defstruct (ir2-block (:include block-annotation)
106 (:constructor make-ir2-block (block)))
107 ;; The IR2-Block's number, which differs from Block's Block-Number if any
108 ;; blocks are split. This is assigned by lifetime analysis.
109 (number nil :type (or index null))
110 ;; Information about unknown-values continuations that is used by stack
111 ;; analysis to do stack simulation. A unknown-values continuation is Pushed
112 ;; if its Dest is in another block. Similarly, a continuation is Popped if
113 ;; its Dest is in this block but has its uses elsewhere. The continuations
114 ;; are in the order that are pushed/popped in the block. Note that the args
115 ;; to a single MV-Combination appear reversed in Popped, since we must
116 ;; effectively pop the last argument first. All pops must come before all
117 ;; pushes (although internal MV uses may be interleaved.) Popped is computed
118 ;; by LTN, and Pushed is computed by stack analysis.
119 (pushed () :type list)
120 (popped () :type list)
121 ;; The result of stack analysis: lists of all the unknown-values
122 ;; continuations on the stack at the block start and end, topmost
123 ;; continuation first.
124 (start-stack () :type list)
125 (end-stack () :type list)
126 ;; The first and last VOP in this block. If there are none, both slots are
128 (start-vop nil :type (or vop null))
129 (last-vop nil :type (or vop null))
130 ;; Number of local TNs actually allocated.
131 (local-tn-count 0 :type local-tn-count)
132 ;; A vector that maps local TN numbers to TNs. Some entries may be NIL,
133 ;; indicating that that number is unused. (This allows us to delete local
134 ;; conflict information without compressing the LTN numbers.)
136 ;; If an entry is :More, then this block contains only a single VOP. This
137 ;; VOP has so many more arguments and/or results that they cannot all be
138 ;; assigned distinct LTN numbers. In this case, we assign all the more args
139 ;; one LTN number, and all the more results another LTN number. We can do
140 ;; this, since more operands are referenced simultaneously as far as conflict
141 ;; analysis is concerned. Note that all these :More TNs will be global TNs.
142 (local-tns (make-array local-tn-limit) :type local-tn-vector)
143 ;; Bit-vectors used during lifetime analysis to keep track of references to
144 ;; local TNs. When indexed by the LTN number, the index for a TN is non-zero
145 ;; in Written if it is ever written in the block, and in Live-Out if
146 ;; the first reference is a read.
147 (written (make-array local-tn-limit :element-type 'bit
149 :type local-tn-bit-vector)
150 (live-out (make-array local-tn-limit :element-type 'bit)
151 :type local-tn-bit-vector)
152 ;; Similar to the above, but is updated by lifetime flow analysis to have a 1
153 ;; for LTN numbers of TNs live at the end of the block. This takes into
154 ;; account all TNs that aren't :Live.
155 (live-in (make-array local-tn-limit :element-type 'bit
157 :type local-tn-bit-vector)
158 ;; A thread running through the global-conflicts structures for this block,
159 ;; sorted by TN number.
160 (global-tns nil :type (or global-conflicts null))
161 ;; The assembler label that points to the beginning of the code for this
162 ;; block. Null when we haven't assigned a label yet.
164 ;; List of Location-Info structures describing all the interesting (to the
165 ;; debugger) locations in this block.
166 (locations nil :type list))
168 (defprinter (ir2-block)
169 (pushed :test pushed)
170 (popped :test popped)
171 (start-vop :test start-vop)
172 (last-vop :test last-vop)
173 (local-tn-count :test (not (zerop local-tn-count)))
174 (%label :test %label))
176 ;;; The IR2-Continuation structure is used to annotate continuations that are
177 ;;; used as a function result continuation or that receive MVs.
178 (defstruct (ir2-continuation
179 (:constructor make-ir2-continuation (primitive-type)))
180 ;; If this is :Delayed, then this is a single value continuation for which
181 ;; the evaluation of the use is to be postponed until the evaluation of
182 ;; destination. This can be done for ref nodes or predicates whose
183 ;; destination is an IF.
185 ;; If this is :Fixed, then this continuation has a fixed number of values,
186 ;; with the TNs in Locs.
188 ;; If this is :Unknown, then this is an unknown-values continuation, using
189 ;; the passing locations in Locs.
191 ;; If this is :Unused, then this continuation should never actually be used
192 ;; as the destination of a value: it is only used tail-recursively.
193 (kind :fixed :type (member :delayed :fixed :unknown :unused))
194 ;; The primitive-type of the first value of this continuation. This is
195 ;; primarily for internal use during LTN, but it also records the type
196 ;; restriction on delayed references. In multiple-value contexts, this is
197 ;; null to indicate that it is meaningless. This is always (primitive-type
198 ;; (continuation-type cont)), which may be more restrictive than the
199 ;; tn-primitive-type of the value TN. This is becase the value TN must hold
200 ;; any possible type that could be computed (before type checking.)
201 (primitive-type nil :type (or primitive-type null))
202 ;; Locations used to hold the values of the continuation. If the number
203 ;; of values if fixed, then there is one TN per value. If the number of
204 ;; values is unknown, then this is a two-list of TNs holding the start of the
205 ;; values glob and the number of values. Note that since type checking is
206 ;; the responsibility of the values receiver, these TNs primitive type is
207 ;; only based on the proven type information.
208 (locs nil :type list))
210 (defprinter (ir2-continuation)
215 ;;; The IR2-Component serves mostly to accumulate non-code information about
216 ;;; the component being compiled.
217 (defstruct ir2-component
218 ;; The counter used to allocate global TN numbers.
219 (global-tn-counter 0 :type index)
220 ;; Normal-TNs is the head of the list of all the normal TNs that need to be
221 ;; packed, linked through the Next slot. We place TNs on this list when we
222 ;; allocate them so that Pack can find them.
224 ;; Restricted-TNs are TNs that must be packed within a finite SC. We pack
225 ;; these TNs first to ensure that the restrictions will be satisfied (if
228 ;; Wired-TNs are TNs that must be packed at a specific location. The SC
229 ;; and Offset are already filled in.
231 ;; Constant-TNs are non-packed TNs that represent constants. :Constant TNs
232 ;; may eventually be converted to :Cached-Constant normal TNs.
233 (normal-tns nil :type (or tn null))
234 (restricted-tns nil :type (or tn null))
235 (wired-tns nil :type (or tn null))
236 (constant-tns nil :type (or tn null))
237 ;; A list of all the :COMPONENT TNs (live throughout the component.) These
238 ;; TNs will also appear in the {NORMAL,RESTRICTED,WIRED} TNs as appropriate
239 ;; to their location.
240 (component-tns () :type list)
241 ;; If this component has a NFP, then this is it.
242 (nfp nil :type (or tn null))
243 ;; A list of the explicitly specified save TNs (kind :SPECIFIED-SAVE). These
244 ;; TNs will also appear in the {NORMAL,RESTRICTED,WIRED} TNs as appropriate
245 ;; to their location.
246 (specified-save-tns () :type list)
247 ;; Values-Receivers is a list of all the blocks whose ir2-block has a
248 ;; non-null value for Popped. This slot is initialized by LTN-Analyze as an
249 ;; input to Stack-Analyze.
250 (values-receivers nil :type list)
251 ;; An adjustable vector that records all the constants in the constant pool.
252 ;; A non-immediate :Constant TN with offset 0 refers to the constant in
253 ;; element 0, etc. Normal constants are represented by the placing the
254 ;; Constant leaf in this vector. A load-time constant is distinguished by
255 ;; being a cons (Kind . What). Kind is a keyword indicating how the constant
256 ;; is computed, and What is some context.
258 ;; These load-time constants are recognized:
260 ;; (:entry . <function>)
261 ;; Is replaced by the code pointer for the specified function. This is
262 ;; how compiled code (including DEFUN) gets its hands on a function.
263 ;; <function> is the XEP lambda for the called function; its Leaf-Info
264 ;; should be an Entry-Info structure.
266 ;; (:label . <label>)
267 ;; Is replaced with the byte offset of that label from the start of the
268 ;; code vector (including the header length.)
270 ;; A null entry in this vector is a placeholder for implementation overhead
271 ;; that is eventually stuffed in somehow.
272 (constants (make-array 10 :fill-pointer 0 :adjustable t) :type vector)
273 ;; Some kind of info about the component's run-time representation. This is
274 ;; filled in by the VM supplied Select-Component-Format function.
276 ;; A list of the Entry-Info structures describing all of the entries into
277 ;; this component. Filled in by entry analysis.
278 (entries nil :type list)
279 ;; Head of the list of :ALIAS TNs in this component, threaded by TN-NEXT.
280 (alias-tns nil :type (or tn null))
281 ;; Spilled-VOPs is a hashtable translating from "interesting" VOPs to a list
282 ;; of the TNs spilled at that VOP. This is used when computing debug info so
283 ;; that we don't consider the TN's value to be valid when it is in fact
284 ;; somewhere else. Spilled-TNs has T for every "interesting" TN that is ever
285 ;; spilled, providing a representation that is more convenient some places.
286 (spilled-vops (make-hash-table :test 'eq) :type hash-table)
287 (spilled-tns (make-hash-table :test 'eq) :type hash-table)
288 ;; Dynamic vop count info. This is needed by both ir2-convert and
289 ;; setup-dynamic-count-info. (But only if we are generating code to
290 ;; collect dynamic statistics.)
292 (dyncount-info nil :type (or null dyncount-info)))
294 ;;; The Entry-Info structure condenses all the information that the dumper
295 ;;; needs to create each XEP's function entry data structure. The Entry-Info
296 ;;; structures are somtimes created before they are initialized, since ir2
297 ;;; conversion may need to compile a forward reference. In this case
298 ;;; the slots aren't actually initialized until entry analysis runs.
299 (defstruct entry-info
300 ;; True if this function has a non-null closure environment.
301 (closure-p nil :type boolean)
302 ;; A label pointing to the entry vector for this function. Null until
303 ;; ENTRY-ANALYZE runs.
304 (offset nil :type (or label null))
305 ;; If this function was defined using DEFUN, then this is the name of the
306 ;; function, a symbol or (SETF <symbol>). Otherwise, this is some string
307 ;; that is intended to be informative.
308 (name "<not computed>" :type (or simple-string list symbol))
309 ;; A string representing the argument list that the function was defined
311 (arguments nil :type (or simple-string null))
312 ;; A function type specifier representing the arguments and results of this
314 (type 'function :type (or list (member function))))
316 ;;; An IR2-ENVIRONMENT is used to annotate non-LET lambdas with their passing
317 ;;; locations. It is stored in the Environment-Info.
318 (defstruct ir2-environment
319 ;; The TNs that hold the passed environment within the function. This is an
320 ;; alist translating from the NLX-Info or lambda-var to the TN that holds
321 ;; the corresponding value within this function. This list is in the same
322 ;; order as the ENVIRONMENT-CLOSURE.
323 (environment nil :type list)
324 ;; The TNs that hold the Old-Fp and Return-PC within the function. We
325 ;; always save these so that the debugger can do a backtrace, even if the
326 ;; function has no return (and thus never uses them). Null only temporarily.
327 (old-fp nil :type (or tn null))
328 (return-pc nil :type (or tn null))
329 ;; The passing location for the Return-PC. The return PC is treated
330 ;; differently from the other arguments, since in some implementations we may
331 ;; use a call instruction that requires the return PC to be passed in a
333 (return-pc-pass (required-argument) :type tn)
334 ;; True if this function has a frame on the number stack. This is set by
335 ;; representation selection whenever it is possible that some function in
336 ;; our tail set will make use of the number stack.
337 (number-stack-p nil :type boolean)
338 ;; A list of all the :Environment TNs live in this environment.
339 (live-tns nil :type list)
340 ;; A list of all the :Debug-Environment TNs live in this environment.
341 (debug-live-tns nil :type list)
342 ;; A label that marks the start of elsewhere code for this function. Null
343 ;; until this label is assigned by codegen. Used for maintaining the debug
345 (elsewhere-start nil :type (or label null))
346 ;; A label that marks the first location in this function at which the
347 ;; environment is properly initialized, i.e. arguments moved from their
348 ;; passing locations, etc. This is the start of the function as far as the
349 ;; debugger is concerned.
350 (environment-start nil :type (or label null)))
351 (defprinter (ir2-environment)
357 ;;; The RETURN-INFO structure is used by GTN to represent the return
358 ;;; strategy and locations for all the functions in a given TAIL-SET.
359 ;;; It is stored in the TAIL-SET-INFO.
360 (defstruct return-info
361 ;; The return convention used:
362 ;; -- If :Unknown, we use the standard return convention.
363 ;; -- If :Fixed, we use the known-values convention.
364 (kind (required-argument) :type (member :fixed :unknown))
365 ;; The number of values returned, or :Unknown if we don't know. Count may be
366 ;; known when Kind is :Unknown, since we may choose the standard return
367 ;; convention for other reasons.
368 (count (required-argument) :type (or index (member :unknown)))
369 ;; If count isn't :Unknown, then this is a list of the primitive-types of
371 (types () :type list)
372 ;; If kind is :Fixed, then this is the list of the TNs that we return the
374 (locations () :type list))
375 (defprinter (return-info)
381 (defstruct ir2-nlx-info
382 ;; If the kind is :ENTRY (a lexical exit), then in the home
383 ;; environment, this holds a VALUE-CELL object containing the unwind
384 ;; block pointer. In the other cases nobody directly references the
385 ;; unwind-block, so we leave this slot null.
386 (home nil :type (or tn null))
387 ;; The saved control stack pointer.
388 (save-sp (required-argument) :type tn)
389 ;; The list of dynamic state save TNs.
390 (dynamic-state (list* (make-stack-pointer-tn)
391 (make-dynamic-state-tns))
393 ;; The target label for NLX entry.
394 (target (gen-label) :type label))
395 (defprinter (ir2-nlx-info)
400 ;;; FIXME: Delete? (was commented out in CMU CL)
402 ;;; The Loop structure holds information about a loop.
403 (defstruct (cloop (:conc-name loop-)
405 (:constructor make-loop)
407 ;; The kind of loop that this is. These values are legal:
410 ;; This is the outermost loop structure, and represents all the
411 ;; code in a component.
414 ;; A normal loop with only one entry.
417 ;; A segment of a "strange loop" in a non-reducible flow graph.
418 (kind (required-argument) :type (member :outer :natural :strange))
419 ;; The first and last blocks in the loop. There may be more than one tail,
420 ;; since there may be multiple back branches to the same head.
421 (head nil :type (or cblock null))
422 (tail nil :type list)
423 ;; A list of all the blocks in this loop or its inferiors that have a
424 ;; successor outside of the loop.
425 (exits nil :type list)
426 ;; The loop that this loop is nested within. This is null in the outermost
428 (superior nil :type (or cloop null))
429 ;; A list of the loops nested directly within this one.
430 (inferiors nil :type list)
431 ;; The head of the list of blocks directly within this loop. We must recurse
432 ;; on Inferiors to find all the blocks.
433 (blocks nil :type (or null cblock)))
441 ;;;; VOPs and templates
443 ;;; A VOP is a Virtual Operation. It represents an operation and the
444 ;;; operands to the operation.
445 (defstruct (vop (:constructor make-vop (block node info args results)))
446 ;; VOP-Info structure containing static info about the operation.
447 (info nil :type (or vop-info null))
448 ;; The IR2-Block this VOP is in.
449 (block (required-argument) :type ir2-block)
450 ;; VOPs evaluated after and before this one. Null at the
451 ;; beginning/end of the block, and temporarily during IR2
453 (next nil :type (or vop null))
454 (prev nil :type (or vop null))
455 ;; Heads of the TN-Ref lists for operand TNs, linked using the
457 (args nil :type (or tn-ref null))
458 (results nil :type (or tn-ref null))
459 ;; Head of the list of write refs for each explicitly allocated
460 ;; temporary, linked together using the Across slot.
461 (temps nil :type (or tn-ref null))
462 ;; Head of the list of all TN-refs for references in this VOP,
463 ;; linked by the Next-Ref slot. There will be one entry for each
464 ;; operand and two (a read and a write) for each temporary.
465 (refs nil :type (or tn-ref null))
466 ;; Stuff that is passed uninterpreted from IR2 conversion to
467 ;; codegen. The meaning of this slot is totally dependent on the VOP.
469 ;; Node that generated this VOP, for keeping track of debug info.
470 (node nil :type (or node null))
471 ;; Local-TN bit vector representing the set of TNs live after args
472 ;; are read and before results are written. This is only filled in
473 ;; when VOP-INFO-SAVE-P is non-null.
474 (save-set nil :type (or local-tn-bit-vector null)))
476 (info :prin1 (vop-info-name info))
479 (codegen-info :test codegen-info))
481 ;;; A TN-REF object contains information about a particular reference
482 ;;; to a TN. The information in TN-REFs largely determines how TNs are
484 (defstruct (tn-ref (:constructor make-tn-ref (tn write-p)))
486 (tn (required-argument) :type tn)
487 ;; Is this is a write reference? (as opposed to a read reference)
488 (write-p nil :type boolean)
489 ;; the link for a list running through all TN-Refs for this TN of
490 ;; the same kind (read or write)
491 (next nil :type (or tn-ref null))
492 ;; the VOP where the reference happens, or NIL temporarily
493 (vop nil :type (or vop null))
494 ;; the link for a list of all TN-Refs in VOP, in reverse order of
496 (next-ref nil :type (or tn-ref null))
497 ;; the link for a list of the TN-Refs in VOP of the same kind
498 ;; (argument, result, temp)
499 (across nil :type (or tn-ref null))
500 ;; If true, this is a TN-Ref also in VOP whose TN we would like
501 ;; packed in the same location as our TN. Read and write refs are
502 ;; always paired: Target in the read points to the write, and
504 (target nil :type (or null tn-ref))
505 ;; the load TN allocated for this operand, if any
506 (load-tn nil :type (or tn null)))
510 (vop :test vop :prin1 (vop-info-name (vop-info vop))))
512 ;;; A TEMPLATE object represents a particular IR2 coding strategy for
513 ;;; a known function.
514 (def!struct (template (:constructor nil)
515 #-sb-xc-host (:pure t))
516 ;; The symbol name of this VOP. This is used when printing the VOP
517 ;; and is also used to provide a handle for definition and
519 (name nil :type symbol)
520 ;; A Function-Type describing the arg/result type restrictions. We
521 ;; compute this from the Primitive-Type restrictions to make life
522 ;; easier for IR1 phases that need to anticipate LTN's template
524 (type (required-argument) :type function-type)
525 ;; Lists of restrictions on the argument and result types. A
526 ;; restriction may take several forms:
527 ;; -- The restriction * is no restriction at all.
528 ;; -- A restriction (:OR <primitive-type>*) means that the operand
529 ;; must have one of the specified primitive types.
530 ;; -- A restriction (:CONSTANT <predicate> <type-spec>) means that the
531 ;; argument (not a result) must be a compile-time constant that
532 ;; satisfies the specified predicate function. In this case, the
533 ;; constant value will be passed as an info argument rather than
534 ;; as a normal argument. <type-spec> is a Lisp type specifier for
535 ;; the type tested by the predicate, used when we want to represent
536 ;; the type constraint as a Lisp function type.
538 ;; If Result-Types is :Conditional, then this is an IF-xxx style
539 ;; conditional that yeilds its result as a control transfer. The
540 ;; emit function takes two info arguments: the target label and a
541 ;; boolean flag indicating whether to negate the sense of the test.
542 (arg-types nil :type list)
543 (result-types nil :type (or list (member :conditional)))
544 ;; The primitive type restriction applied to each extra argument or
545 ;; result following the fixed operands. If NIL, no extra
546 ;; args/results are allowed. Otherwise, either * or a (:OR ...) list
547 ;; as described for the {ARG,RESULT}-TYPES.
548 (more-args-type nil :type (or (member nil *) cons))
549 (more-results-type nil :type (or (member nil *) cons))
550 ;; If true, this is a function that is called with no arguments to
551 ;; see whether this template can be emitted. This is used to
552 ;; conditionally compile for different target hardware
553 ;; configuarations (e.g. FP hardware.)
554 (guard nil :type (or function null))
555 ;; The policy under which this template is the best translation.
556 ;; Note that LTN might use this template under other policies if it
557 ;; can't figure our anything better to do.
558 (policy (required-argument) :type policies)
559 ;; The base cost for this template, given optimistic assumptions
560 ;; such as no operand loading, etc.
561 (cost (required-argument) :type index)
562 ;; If true, then a short noun-like phrase describing what this VOP
563 ;; "does", i.e. the implementation strategy. This is for use in
565 (note nil :type (or string null))
566 ;; The number of trailing arguments to VOP or %PRIMITIVE that we
567 ;; bundle into a list and pass into the emit function. This provides
568 ;; a way to pass uninterpreted stuff directly to the code generator.
569 (info-arg-count 0 :type index)
570 ;; A function that emits the VOPs for this template. Arguments:
571 ;; 1] Node for source context.
572 ;; 2] IR2-Block that we place the VOP in.
573 ;; 3] This structure.
574 ;; 4] Head of argument TN-Ref list.
575 ;; 5] Head of result TN-Ref list.
576 ;; 6] If Info-Arg-Count is non-zero, then a list of the magic
579 ;; Two values are returned: the first and last VOP emitted. This vop
580 ;; sequence must be linked into the VOP Next/Prev chain for the
581 ;; block. At least one VOP is always emitted.
582 (emit-function (required-argument) :type function))
583 (defprinter (template)
587 (more-args-type :test more-args-type :prin1 more-args-type)
588 (more-results-type :test more-results-type :prin1 more-results-type)
592 (info-arg-count :test (not (zerop info-arg-count))))
594 ;;; A VOP-INFO object holds the constant information for a given
595 ;;; virtual operation. We include TEMPLATE so that functions with a
596 ;;; direct VOP equivalent can be translated easily.
597 (def!struct (vop-info
599 (:make-load-form-fun ignore-it))
600 ;; Side-effects of this VOP and side-effects that affect the value
602 (effects (required-argument) :type attributes)
603 (affected (required-argument) :type attributes)
604 ;; If true, causes special casing of TNs live after this VOP that
606 ;; -- If T, all such TNs that are allocated in a SC with a defined
607 ;; save-sc will be saved in a TN in the save SC before the VOP
608 ;; and restored after the VOP. This is used by call VOPs. A bit
609 ;; vector representing the live TNs is stored in the VOP-SAVE-SET.
610 ;; -- If :Force-To-Stack, all such TNs will made into :Environment TNs
611 ;; and forced to be allocated in SCs without any save-sc. This is
612 ;; used by NLX entry vops.
613 ;; -- If :Compute-Only, just compute the save set, don't do any saving.
614 ;; This is used to get the live variables for debug info.
615 (save-p nil :type (member t nil :force-to-stack :compute-only))
616 ;; Info for automatic emission of move-arg VOPs by representation
617 ;; selection. If NIL, then do nothing special. If non-null, then
618 ;; there must be a more arg. Each more arg is moved to its passing
619 ;; location using the appropriate representation-specific
620 ;; move-argument VOP. The first (fixed) argument must be the
621 ;; control-stack frame pointer for the frame to move into. The first
622 ;; info arg is the list of passing locations.
624 ;; Additional constraints depend on the value:
630 ;; The second (fixed) arg is the NFP for the called function (from
634 ;; If needed, the old NFP is computed using COMPUTE-OLD-NFP.
635 (move-args nil :type (member nil :full-call :local-call :known-return))
636 ;; A list of sc-vectors representing the loading costs of each fixed
637 ;; argument and result.
638 (arg-costs nil :type list)
639 (result-costs nil :type list)
640 ;; If true, sc-vectors representing the loading costs for any more
642 (more-arg-costs nil :type (or sc-vector null))
643 (more-result-costs nil :type (or sc-vector null))
644 ;; Lists of sc-vectors mapping each SC to the SCs that we can load
645 ;; into. If a SC is directly acceptable to the VOP, then the entry
646 ;; is T. Otherwise, it is a list of the SC numbers of all the SCs
647 ;; that we can load into. This list will be empty if there is no
648 ;; load function which loads from that SC to an SC allowed by the
649 ;; operand SC restriction.
650 (arg-load-scs nil :type list)
651 (result-load-scs nil :type list)
652 ;; If true, a function that is called with the VOP to do operand
653 ;; targeting. This is done by modifiying the TN-Ref-Target slots in
654 ;; the TN-Refs so that they point to other TN-Refs in the same VOP.
655 (target-function nil :type (or null function))
656 ;; A function that emits assembly code for a use of this VOP when it
657 ;; is called with the VOP structure. Null if this VOP has no
658 ;; specified generator (i.e. it exists only to be inherited by other
660 (generator-function nil :type (or function null))
661 ;; A list of things that are used to parameterize an inherited
662 ;; generator. This allows the same generator function to be used for
663 ;; a group of VOPs with similar implementations.
664 (variant nil :type list)
665 ;; The number of arguments and results. Each regular arg/result
666 ;; counts as one, and all the more args/results together count as 1.
667 (num-args 0 :type index)
668 (num-results 0 :type index)
669 ;; Vector of the temporaries the vop needs. See emit-generic-vop in
670 ;; vmdef for information on how the temps are encoded.
672 ;; (The SB-XC-HOST conditionalization on the type is there because
673 ;; it's difficult to dump specialized arrays portably, so on the
674 ;; cross-compilation host we punt by using unspecialized arrays
676 (temps nil :type (or null (specializable-vector (unsigned-byte 16))))
677 ;; The order all the refs for this vop should be put in. Each
678 ;; operand is assigned a number in the following ordering: args,
679 ;; more-args, results, more-results, temps This vector represents
680 ;; the order the operands should be put into in the next-ref link.
682 ;; (The SB-XC-HOST conditionalization on the type is there because
683 ;; it's difficult to dump specialized arrays portably, so on the
684 ;; cross-compilation host we punt by using unspecialized arrays
686 (ref-ordering nil :type (or null (specializable-vector (unsigned-byte 8))))
687 ;; Array of the various targets that should be done. Each element
688 ;; encodes the source ref (shifted 8) and the dest ref index.
689 (targets nil :type (or null (specializable-vector (unsigned-byte 16)))))
693 ;;; copied from docs/internals/retargeting.tex by WHN 19990707:
695 ;;; A Storage Base represents a physical storage resource such as a
696 ;;; register set or stack frame. Storage bases for non-global
697 ;;; resources such as the stack are relativized by the environment
698 ;;; that the TN is allocated in. Packing conflict information is kept
699 ;;; in the storage base, but non-packed storage resources such as
700 ;;; closure environments also have storage bases.
702 ;;; Some storage bases:
703 ;;; General purpose registers
704 ;;; Floating point registers
705 ;;; Boxed (control) stack environment
706 ;;; Unboxed (number) stack environment
707 ;;; Closure environment
709 ;;; A storage class is a potentially arbitrary set of the elements in
710 ;;; a storage base. Although conceptually there may be a hierarchy of
711 ;;; storage classes such as "all registers", "boxed registers", "boxed
712 ;;; scratch registers", this doesn't exist at the implementation
713 ;;; level. Such things can be done by specifying storage classes whose
714 ;;; locations overlap. A TN shouldn't have lots of overlapping SC's as
715 ;;; legal SC's, since time would be wasted repeatedly attempting to
716 ;;; pack in the same locations.
721 ;;; Reg: any register (immediate objects)
722 ;;; Save-Reg: a boxed register near r15 (registers easily saved in a call)
723 ;;; Boxed-Reg: any boxed register (any boxed object)
724 ;;; Unboxed-Reg: any unboxed register (any unboxed object)
725 ;;; Float-Reg, Double-Float-Reg: float in FP register.
726 ;;; Stack: boxed object on the stack (on cstack)
727 ;;; Word: any 32bit unboxed object on nstack.
728 ;;; Double: any 64bit unboxed object on nstack.
730 ;;; The SB structure represents the global information associated with
732 (def!struct (sb (:make-load-form-fun just-dump-it-normally))
733 ;; Name, for printing and reference.
734 (name nil :type symbol)
735 ;; The kind of storage base (which determines the packing
737 (kind :non-packed :type (member :finite :unbounded :non-packed))
738 ;; The number of elements in the SB. If finite, this is the total
739 ;; size. If unbounded, this is the size that the SB is initially
741 (size 0 :type index))
745 ;;; The Finite-SB structure holds information needed by the packing
746 ;;; algorithm for finite SBs.
747 (def!struct (finite-sb (:include sb))
748 ;; The number of locations currently allocated in this SB.
749 (current-size 0 :type index)
750 ;; The last location packed in, used by pack to scatter TNs to
751 ;; prevent a few locations from getting all the TNs, and thus
752 ;; getting overcrowded, reducing the possiblilities for targeting.
753 (last-offset 0 :type index)
754 ;; A vector containing, for each location in this SB, a vector
755 ;; indexed by IR2 block numbers, holding local conflict bit vectors.
756 ;; A TN must not be packed in a given location within a particular
757 ;; block if the LTN number for that TN in that block corresponds to
758 ;; a set bit in the bit-vector.
759 (conflicts '#() :type simple-vector)
760 ;; A vector containing, for each location in this SB, a bit-vector
761 ;; indexed by IR2 block numbers. If the bit corresponding to a block
762 ;; is set, then the location is in use somewhere in the block, and
763 ;; thus has a conflict for always-live TNs.
764 (always-live '#() :type simple-vector)
765 ;; A vector containing the TN currently live in each location in the
766 ;; SB, or NIL if the location is unused. This is used during load-tn pack.
767 (live-tns '#() :type simple-vector)
768 ;; The number of blocks for which the ALWAYS-LIVE and CONFLICTS
769 ;; might not be virgin, and thus must be reinitialized when PACK
770 ;; starts. Less then the length of those vectors when not all of the
771 ;; length was used on the previously packed component.
772 (last-block-count 0 :type index))
774 ;;; the SC structure holds the storage base that storage is allocated
775 ;;; in and information used to select locations within the SB.
777 ;; Name, for printing and reference.
778 (name nil :type symbol)
779 ;; The number used to index SC cost vectors.
780 (number 0 :type sc-number)
781 ;; The storage base that this SC allocates storage from.
782 (sb nil :type (or sb null))
783 ;; The size of elements in this SC, in units of locations in the SB.
784 (element-size 0 :type index)
785 ;; If our SB is finite, a list of the locations in this SC.
786 (locations nil :type list)
787 ;; A list of the alternate (save) SCs for this SC.
788 (alternate-scs nil :type list)
789 ;; A list of the constant SCs that can me moved into this SC.
790 (constant-scs nil :type list)
791 ;; True if this values in this SC needs to be saved across calls.
792 (save-p nil :type boolean)
793 ;; Vectors mapping from SC numbers to information about how to load
794 ;; from the index SC to this one. Move-Functions holds the names of
795 ;; the functions used to do loading, and Load-Costs holds the cost
796 ;; of the corresponding Move-Functions. If loading is impossible,
797 ;; then the entries are NIL. Load-Costs is initialized to have a 0
799 (move-functions (make-array sc-number-limit :initial-element nil)
801 (load-costs (make-array sc-number-limit :initial-element nil)
803 ;; A vector mapping from SC numbers to possibly
804 ;; representation-specific move and coerce VOPs. Each entry is a
805 ;; list of VOP-INFOs for VOPs that move/coerce an object in the
806 ;; index SC's representation into this SC's representation. This
807 ;; vector is filled out with entries for all SCs that can somehow be
808 ;; coerced into this SC, not just those VOPs defined to directly
809 ;; move into this SC (i.e. it allows for operand loading on the move
812 ;; When there are multiple applicable VOPs, the template arg and
813 ;; result type restrictions are used to determine which one to use.
814 ;; The list is sorted by increasing cost, so the first applicable
815 ;; VOP should be used.
817 ;; Move (or move-arg) VOPs with descriptor results shouldn't have
818 ;; TNs wired in the standard argument registers, since there may
819 ;; already be live TNs wired in those locations holding the values
820 ;; that we are setting up for unknown-values return.
821 (move-vops (make-array sc-number-limit :initial-element nil)
823 ;; The costs corresponding to the MOVE-VOPS. Separate because this
824 ;; info is needed at meta-compile time, while the MOVE-VOPs don't
825 ;; exist till load time. If no move is defined, then the entry is
827 (move-costs (make-array sc-number-limit :initial-element nil)
829 ;; Similar to Move-VOPs, except that we only ever use the entries
830 ;; for this SC and its alternates, since we never combine complex
831 ;; representation conversion with argument passing.
832 (move-arg-vops (make-array sc-number-limit :initial-element nil)
834 ;; True if this SC or one of its alternates in in the NUMBER-STACK SB.
835 (number-stack-p nil :type boolean)
836 ;; Alignment restriction. The offset must be an even multiple of this.
837 (alignment 1 :type (and index (integer 1)))
838 ;; A list of locations that we avoid packing in during normal
839 ;; register allocation to ensure that these locations will be free
840 ;; for operand loading. This prevents load-TN packing from thrashing
841 ;; by spilling a lot.
842 (reserve-locations nil :type list))
848 (defstruct (tn (:include sset-element)
849 (:constructor make-random-tn)
850 (:constructor make-tn (number kind primitive-type sc)))
851 ;; The kind of TN this is:
854 ;; A normal, non-constant TN, representing a variable or temporary.
855 ;; Lifetime information is computed so that packing can be done.
858 ;; A TN that has hidden references (debugger or NLX), and thus must be
859 ;; allocated for the duration of the environment it is referenced in.
861 ;; :DEBUG-ENVIRONMENT
862 ;; Like :ENVIRONMENT, but is used for TNs that we want to be able to
863 ;; target to/from and that don't absolutely have to be live
864 ;; everywhere. These TNs are live in all blocks in the environment
865 ;; that don't reference this TN.
868 ;; A TN that implicitly conflicts with all other TNs. No conflict
873 ;; A TN used for saving a :Normal TN across function calls. The
874 ;; lifetime information slots are unitialized: get the original
875 ;; TN our of the SAVE-TN slot and use it for conflicts. Save-Once
876 ;; is like :Save, except that it is only save once at the single
877 ;; writer of the original TN.
880 ;; A TN that was explicitly specified as the save TN for another TN.
881 ;; When we actually get around to doing the saving, this will be
882 ;; changed to :SAVE or :SAVE-ONCE.
885 ;; A load-TN used to compute an argument or result that is
886 ;; restricted to some finite SB. Load TNs don't have any conflict
887 ;; information. Load TN pack uses a special local conflict
888 ;; determination method.
891 ;; Represents a constant, with TN-Leaf a Constant leaf. Lifetime
892 ;; information isn't computed, since the value isn't allocated by
893 ;; pack, but is instead generated as a load at each use. Since
894 ;; lifetime analysis isn't done on :Constant TNs, they don't have
895 ;; Local-Numbers and similar stuff.
898 ;; A special kind of TN used to represent initialization of local
899 ;; call arguments in the caller. It provides another name for the
900 ;; argument TN so that lifetime analysis doesn't get confused by
901 ;; self-recursive calls. Lifetime analysis treats this the same
902 ;; as :NORMAL, but then at the end merges the conflict info into
903 ;; the original TN and replaces all uses of the alias with the
904 ;; original TN. SAVE-TN holds the aliased TN.
905 (kind (required-argument)
906 :type (member :normal :environment :debug-environment
907 :save :save-once :specified-save :load :constant
909 ;; The primitive-type for this TN's value. Null in restricted or
911 (primitive-type nil :type (or primitive-type null))
912 ;; If this TN represents a variable or constant, then this is the
913 ;; corresponding Leaf.
914 (leaf nil :type (or leaf null))
915 ;; Thread that links TNs together so that we can find them.
916 (next nil :type (or tn null))
917 ;; Head of TN-Ref lists for reads and writes of this TN.
918 (reads nil :type (or tn-ref null))
919 (writes nil :type (or tn-ref null))
920 ;; A link we use when building various temporary TN lists.
921 (next* nil :type (or tn null))
922 ;; Some block that contains a reference to this TN, or Nil if we
923 ;; haven't seen any reference yet. If the TN is local, then this is
924 ;; the block it is local to.
925 (local nil :type (or ir2-block null))
926 ;; If a local TN, the block relative number for this TN. Global TNs
927 ;; whose liveness changes within a block are also assigned a local
928 ;; number during the conflicts analysis of that block. If the TN has
929 ;; no local number within the block, then this is Nil.
930 (local-number nil :type (or local-tn-number null))
931 ;; If a local TN, a bit-vector with 1 for the local-number of every
932 ;; TN that we conflict with.
933 (local-conflicts (make-array local-tn-limit :element-type 'bit
935 :type local-tn-bit-vector)
936 ;; Head of the list of Global-Conflicts structures for a global TN.
937 ;; This list is sorted by block number (i.e. reverse DFO), allowing
938 ;; the intersection between the lifetimes for two global TNs to be
939 ;; easily found. If null, then this TN is a local TN.
940 (global-conflicts nil :type (or global-conflicts null))
941 ;; During lifetime analysis, this is used as a pointer into the
942 ;; conflicts chain, for scanning through blocks in reverse DFO.
943 (current-conflict nil)
944 ;; In a :SAVE TN, this is the TN saved. In a :NORMAL or :ENVIRONMENT
945 ;; TN, this is the associated save TN. In TNs with no save TN, this
947 (save-tn nil :type (or tn null))
948 ;; After pack, the SC we packed into. Beforehand, the SC we want to
949 ;; pack into, or null if we don't know.
950 (sc nil :type (or sc null))
951 ;; The offset within the SB that this TN is packed into. This is what
952 ;; indicates that the TN is packed.
953 (offset nil :type (or index null))
954 ;; Some kind of info about how important this TN is.
955 (cost 0 :type fixnum)
956 ;; If a :ENVIRONMENT or :DEBUG-ENVIRONMENT TN, this is the environment that
957 ;; the TN is live throughout.
958 (environment nil :type (or environment null)))
959 (def!method print-object ((tn tn) stream)
960 (print-unreadable-object (tn stream :type t)
961 ;; KLUDGE: The distinction between PRINT-TN and PRINT-OBJECT on TN is
962 ;; not very mnemonic. -- WHN 20000124
963 (print-tn tn stream)))
965 ;;; The GLOBAL-CONFLICTS structure represents the conflicts for global
966 ;;; TNs. Each global TN has a list of these structures, one for each
967 ;;; block that it is live in. In addition to repsenting the result of
968 ;;; lifetime analysis, the global conflicts structure is used during
969 ;;; lifetime analysis to represent the set of TNs live at the start of
971 (defstruct (global-conflicts
972 (:constructor make-global-conflicts (kind tn block number)))
973 ;; The IR2-Block that this structure represents the conflicts for.
974 (block (required-argument) :type ir2-block)
975 ;; Thread running through all the Global-Conflict for Block. This
976 ;; thread is sorted by TN number.
977 (next nil :type (or global-conflicts null))
978 ;; The way that TN is used by Block:
981 ;; The TN is read before it is written. It starts the block live,
982 ;; but is written within the block.
985 ;; The TN is written before any read. It starts the block dead,
986 ;; and need not have a read within the block.
989 ;; The TN is read, but never written. It starts the block live,
990 ;; and is not killed by the block. Lifetime analysis will promote
991 ;; :Read-Only TNs to :Live if they are live at the block end.
994 ;; The TN is not referenced. It is live everywhere in the block.
995 (kind :read-only :type (member :read :write :read-only :live))
996 ;; A local conflicts vector representing conflicts with TNs live in
997 ;; Block. The index for the local TN number of each TN we conflict
998 ;; with in this block is 1. To find the full conflict set, the :Live
999 ;; TNs for Block must also be included. This slot is not meaningful
1000 ;; when Kind is :Live.
1001 (conflicts (make-array local-tn-limit
1004 :type local-tn-bit-vector)
1005 ;; The TN we are recording conflicts for.
1006 (tn (required-argument) :type tn)
1007 ;; Thread through all the Global-Conflicts for TN.
1008 (tn-next nil :type (or global-conflicts null))
1009 ;; TN's local TN number in Block. :Live TNs don't have local numbers.
1010 (number nil :type (or local-tn-number null)))
1011 (defprinter (global-conflicts)
1015 (number :test number))