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 (eval-when (:compile-toplevel :load-toplevel :execute)
16 ;; the largest number of TNs whose liveness changes that we can have
18 (defconstant local-tn-limit 64))
20 (deftype local-tn-number () `(integer 0 (,local-tn-limit)))
21 (deftype local-tn-count () `(integer 0 ,local-tn-limit))
22 (deftype local-tn-vector () `(simple-vector ,local-tn-limit))
23 (deftype local-tn-bit-vector () `(simple-bit-vector ,local-tn-limit))
25 ;;; Type of an SC number.
26 (deftype sc-number () `(integer 0 (,sc-number-limit)))
28 ;;; Types for vectors indexed by SC numbers.
29 (deftype sc-vector () `(simple-vector ,sc-number-limit))
30 (deftype sc-bit-vector () `(simple-bit-vector ,sc-number-limit))
32 ;;; The different policies we can use to determine the coding strategy.
34 '(member :safe :small :fast :fast-safe))
38 ;;; The primitive type is used to represent the aspects of type interesting
39 ;;; to the VM. Selection of IR2 translation templates is done on the basis of
40 ;;; the primitive types of the operands, and the primitive type of a value
41 ;;; is used to constrain the possible representations of that value.
42 (defstruct primitive-type
43 ;; The name of this primitive-type.
44 (name nil :type symbol)
45 ;; A list the SC numbers for all the SCs that a TN of this type can be
48 ;; The Lisp type equivalent to this type. If this type could never be
49 ;; returned by Primitive-Type, then this is the NIL (or empty) type.
50 (type (required-argument) :type ctype)
51 ;; The template used to check that an object is of this type. This is a
52 ;; template of one argument and one result, both of primitive-type T. If
53 ;; the argument is of the correct type, then it is delivered into the
54 ;; result. If the type is incorrect, then an error is signalled.
55 (check nil :type (or template null)))
57 (defprinter (primitive-type)
60 ;;;; IR1 annotations used for IR2 conversion
63 ;;; Holds the IR2-Block structure. If there are overflow blocks, then this
64 ;;; points to the first IR2-Block. The Block-Info of the dummy component
65 ;;; head and tail are dummy IR2 blocks that begin and end the emission order
69 ;;; Holds the IR2-Component structure.
72 ;;; Holds the IR2-Continuation structure. Continuations whose values aren't
73 ;;; used won't have any.
76 ;;; If non-null, then a TN in which the affected dynamic environment pointer
77 ;;; should be saved after the binding is instantiated.
80 ;;; Holds the IR2-Environment structure.
83 ;;; Holds the Return-Info structure.
86 ;;; Holds the IR2-NLX-Info structure.
89 ;;; If a non-set lexical variable, the TN that holds the value in the home
90 ;;; environment. If a constant, then the corresponding constant TN.
91 ;;; If an XEP lambda, then the corresponding Entry-Info structure.
93 ;;; Basic-Combination-Info
94 ;;; The template chosen by LTN, or
95 ;;; :FULL if this is definitely a full call.
96 ;;; :FUNNY if this is an oddball thing with IR2-convert.
97 ;;; :LOCAL if this is a local call.
100 ;;; After LTN analysis, this is true only in combination nodes that are
101 ;;; truly tail recursive.
103 ;;; The IR2-Block structure holds information about a block that is used during
104 ;;; and after IR2 conversion. It is stored in the Block-Info slot for the
105 ;;; associated block.
106 (defstruct (ir2-block (:include block-annotation)
107 (:constructor make-ir2-block (block)))
108 ;; The IR2-Block's number, which differs from Block's Block-Number if any
109 ;; blocks are split. This is assigned by lifetime analysis.
110 (number nil :type (or index null))
111 ;; Information about unknown-values continuations that is used by stack
112 ;; analysis to do stack simulation. A unknown-values continuation is Pushed
113 ;; if its Dest is in another block. Similarly, a continuation is Popped if
114 ;; its Dest is in this block but has its uses elsewhere. The continuations
115 ;; are in the order that are pushed/popped in the block. Note that the args
116 ;; to a single MV-Combination appear reversed in Popped, since we must
117 ;; effectively pop the last argument first. All pops must come before all
118 ;; pushes (although internal MV uses may be interleaved.) Popped is computed
119 ;; by LTN, and Pushed is computed by stack analysis.
120 (pushed () :type list)
121 (popped () :type list)
122 ;; The result of stack analysis: lists of all the unknown-values
123 ;; continuations on the stack at the block start and end, topmost
124 ;; continuation first.
125 (start-stack () :type list)
126 (end-stack () :type list)
127 ;; The first and last VOP in this block. If there are none, both slots are
129 (start-vop nil :type (or vop null))
130 (last-vop nil :type (or vop null))
131 ;; Number of local TNs actually allocated.
132 (local-tn-count 0 :type local-tn-count)
133 ;; A vector that maps local TN numbers to TNs. Some entries may be NIL,
134 ;; indicating that that number is unused. (This allows us to delete local
135 ;; conflict information without compressing the LTN numbers.)
137 ;; If an entry is :More, then this block contains only a single VOP. This
138 ;; VOP has so many more arguments and/or results that they cannot all be
139 ;; assigned distinct LTN numbers. In this case, we assign all the more args
140 ;; one LTN number, and all the more results another LTN number. We can do
141 ;; this, since more operands are referenced simultaneously as far as conflict
142 ;; analysis is concerned. Note that all these :More TNs will be global TNs.
143 (local-tns (make-array local-tn-limit) :type local-tn-vector)
144 ;; Bit-vectors used during lifetime analysis to keep track of references to
145 ;; local TNs. When indexed by the LTN number, the index for a TN is non-zero
146 ;; in Written if it is ever written in the block, and in Live-Out if
147 ;; the first reference is a read.
148 (written (make-array local-tn-limit :element-type 'bit
150 :type local-tn-bit-vector)
151 (live-out (make-array local-tn-limit :element-type 'bit)
152 :type local-tn-bit-vector)
153 ;; Similar to the above, but is updated by lifetime flow analysis to have a 1
154 ;; for LTN numbers of TNs live at the end of the block. This takes into
155 ;; account all TNs that aren't :Live.
156 (live-in (make-array local-tn-limit :element-type 'bit
158 :type local-tn-bit-vector)
159 ;; A thread running through the global-conflicts structures for this block,
160 ;; sorted by TN number.
161 (global-tns nil :type (or global-conflicts null))
162 ;; The assembler label that points to the beginning of the code for this
163 ;; block. Null when we haven't assigned a label yet.
165 ;; List of Location-Info structures describing all the interesting (to the
166 ;; debugger) locations in this block.
167 (locations nil :type list))
169 (defprinter (ir2-block)
170 (pushed :test pushed)
171 (popped :test popped)
172 (start-vop :test start-vop)
173 (last-vop :test last-vop)
174 (local-tn-count :test (not (zerop local-tn-count)))
175 (%label :test %label))
177 ;;; The IR2-Continuation structure is used to annotate continuations that are
178 ;;; used as a function result continuation or that receive MVs.
179 (defstruct (ir2-continuation
180 (:constructor make-ir2-continuation (primitive-type)))
181 ;; If this is :Delayed, then this is a single value continuation for which
182 ;; the evaluation of the use is to be postponed until the evaluation of
183 ;; destination. This can be done for ref nodes or predicates whose
184 ;; destination is an IF.
186 ;; If this is :Fixed, then this continuation has a fixed number of values,
187 ;; with the TNs in Locs.
189 ;; If this is :Unknown, then this is an unknown-values continuation, using
190 ;; the passing locations in Locs.
192 ;; If this is :Unused, then this continuation should never actually be used
193 ;; as the destination of a value: it is only used tail-recursively.
194 (kind :fixed :type (member :delayed :fixed :unknown :unused))
195 ;; The primitive-type of the first value of this continuation. This is
196 ;; primarily for internal use during LTN, but it also records the type
197 ;; restriction on delayed references. In multiple-value contexts, this is
198 ;; null to indicate that it is meaningless. This is always (primitive-type
199 ;; (continuation-type cont)), which may be more restrictive than the
200 ;; tn-primitive-type of the value TN. This is becase the value TN must hold
201 ;; any possible type that could be computed (before type checking.)
202 (primitive-type nil :type (or primitive-type null))
203 ;; Locations used to hold the values of the continuation. If the number
204 ;; of values if fixed, then there is one TN per value. If the number of
205 ;; values is unknown, then this is a two-list of TNs holding the start of the
206 ;; values glob and the number of values. Note that since type checking is
207 ;; the responsibility of the values receiver, these TNs primitive type is
208 ;; only based on the proven type information.
209 (locs nil :type list))
211 (defprinter (ir2-continuation)
216 ;;; The IR2-Component serves mostly to accumulate non-code information about
217 ;;; the component being compiled.
218 (defstruct ir2-component
219 ;; The counter used to allocate global TN numbers.
220 (global-tn-counter 0 :type index)
221 ;; Normal-TNs is the head of the list of all the normal TNs that need to be
222 ;; packed, linked through the Next slot. We place TNs on this list when we
223 ;; allocate them so that Pack can find them.
225 ;; Restricted-TNs are TNs that must be packed within a finite SC. We pack
226 ;; these TNs first to ensure that the restrictions will be satisfied (if
229 ;; Wired-TNs are TNs that must be packed at a specific location. The SC
230 ;; and Offset are already filled in.
232 ;; Constant-TNs are non-packed TNs that represent constants. :Constant TNs
233 ;; may eventually be converted to :Cached-Constant normal TNs.
234 (normal-tns nil :type (or tn null))
235 (restricted-tns nil :type (or tn null))
236 (wired-tns nil :type (or tn null))
237 (constant-tns nil :type (or tn null))
238 ;; A list of all the :COMPONENT TNs (live throughout the component.) These
239 ;; TNs will also appear in the {NORMAL,RESTRICTED,WIRED} TNs as appropriate
240 ;; to their location.
241 (component-tns () :type list)
242 ;; If this component has a NFP, then this is it.
243 (nfp nil :type (or tn null))
244 ;; A list of the explicitly specified save TNs (kind :SPECIFIED-SAVE). These
245 ;; TNs will also appear in the {NORMAL,RESTRICTED,WIRED} TNs as appropriate
246 ;; to their location.
247 (specified-save-tns () :type list)
248 ;; Values-Receivers is a list of all the blocks whose ir2-block has a
249 ;; non-null value for Popped. This slot is initialized by LTN-Analyze as an
250 ;; input to Stack-Analyze.
251 (values-receivers nil :type list)
252 ;; An adjustable vector that records all the constants in the constant pool.
253 ;; A non-immediate :Constant TN with offset 0 refers to the constant in
254 ;; element 0, etc. Normal constants are represented by the placing the
255 ;; Constant leaf in this vector. A load-time constant is distinguished by
256 ;; being a cons (Kind . What). Kind is a keyword indicating how the constant
257 ;; is computed, and What is some context.
259 ;; These load-time constants are recognized:
261 ;; (:entry . <function>)
262 ;; Is replaced by the code pointer for the specified function. This is
263 ;; how compiled code (including DEFUN) gets its hands on a function.
264 ;; <function> is the XEP lambda for the called function; its Leaf-Info
265 ;; should be an Entry-Info structure.
267 ;; (:label . <label>)
268 ;; Is replaced with the byte offset of that label from the start of the
269 ;; code vector (including the header length.)
271 ;; A null entry in this vector is a placeholder for implementation overhead
272 ;; that is eventually stuffed in somehow.
273 (constants (make-array 10 :fill-pointer 0 :adjustable t) :type vector)
274 ;; Some kind of info about the component's run-time representation. This is
275 ;; filled in by the VM supplied Select-Component-Format function.
277 ;; A list of the Entry-Info structures describing all of the entries into
278 ;; this component. Filled in by entry analysis.
279 (entries nil :type list)
280 ;; Head of the list of :ALIAS TNs in this component, threaded by TN-NEXT.
281 (alias-tns nil :type (or tn null))
282 ;; Spilled-VOPs is a hashtable translating from "interesting" VOPs to a list
283 ;; of the TNs spilled at that VOP. This is used when computing debug info so
284 ;; that we don't consider the TN's value to be valid when it is in fact
285 ;; somewhere else. Spilled-TNs has T for every "interesting" TN that is ever
286 ;; spilled, providing a representation that is more convenient some places.
287 (spilled-vops (make-hash-table :test 'eq) :type hash-table)
288 (spilled-tns (make-hash-table :test 'eq) :type hash-table)
289 ;; Dynamic vop count info. This is needed by both ir2-convert and
290 ;; setup-dynamic-count-info. (But only if we are generating code to
291 ;; collect dynamic statistics.)
293 (dyncount-info nil :type (or null dyncount-info)))
295 ;;; The Entry-Info structure condenses all the information that the dumper
296 ;;; needs to create each XEP's function entry data structure. The Entry-Info
297 ;;; structures are somtimes created before they are initialized, since ir2
298 ;;; conversion may need to compile a forward reference. In this case
299 ;;; the slots aren't actually initialized until entry analysis runs.
300 (defstruct entry-info
301 ;; True if this function has a non-null closure environment.
302 (closure-p nil :type boolean)
303 ;; A label pointing to the entry vector for this function. Null until
304 ;; ENTRY-ANALYZE runs.
305 (offset nil :type (or label null))
306 ;; If this function was defined using DEFUN, then this is the name of the
307 ;; function, a symbol or (SETF <symbol>). Otherwise, this is some string
308 ;; that is intended to be informative.
309 (name "<not computed>" :type (or simple-string list symbol))
310 ;; A string representing the argument list that the function was defined
312 (arguments nil :type (or simple-string null))
313 ;; A function type specifier representing the arguments and results of this
315 (type 'function :type (or list (member function))))
317 ;;; An IR2-ENVIRONMENT is used to annotate non-LET lambdas with their passing
318 ;;; locations. It is stored in the Environment-Info.
319 (defstruct ir2-environment
320 ;; The TNs that hold the passed environment within the function. This is an
321 ;; alist translating from the NLX-Info or lambda-var to the TN that holds
322 ;; the corresponding value within this function. This list is in the same
323 ;; order as the ENVIRONMENT-CLOSURE.
324 (environment nil :type list)
325 ;; The TNs that hold the Old-Fp and Return-PC within the function. We
326 ;; always save these so that the debugger can do a backtrace, even if the
327 ;; function has no return (and thus never uses them). Null only temporarily.
328 (old-fp nil :type (or tn null))
329 (return-pc nil :type (or tn null))
330 ;; The passing location for the Return-PC. The return PC is treated
331 ;; differently from the other arguments, since in some implementations we may
332 ;; use a call instruction that requires the return PC to be passed in a
334 (return-pc-pass (required-argument) :type tn)
335 ;; True if this function has a frame on the number stack. This is set by
336 ;; representation selection whenever it is possible that some function in
337 ;; our tail set will make use of the number stack.
338 (number-stack-p nil :type boolean)
339 ;; A list of all the :Environment TNs live in this environment.
340 (live-tns nil :type list)
341 ;; A list of all the :Debug-Environment TNs live in this environment.
342 (debug-live-tns nil :type list)
343 ;; A label that marks the start of elsewhere code for this function. Null
344 ;; until this label is assigned by codegen. Used for maintaining the debug
346 (elsewhere-start nil :type (or label null))
347 ;; A label that marks the first location in this function at which the
348 ;; environment is properly initialized, i.e. arguments moved from their
349 ;; passing locations, etc. This is the start of the function as far as the
350 ;; debugger is concerned.
351 (environment-start nil :type (or label null)))
352 (defprinter (ir2-environment)
358 ;;; The Return-Info structure is used by GTN to represent the return strategy
359 ;;; and locations for all the functions in a given Tail-Set. It is stored in
360 ;;; the Tail-Set-Info.
361 (defstruct return-info
362 ;; The return convention used:
363 ;; -- If :Unknown, we use the standard return convention.
364 ;; -- If :Fixed, we use the known-values convention.
365 (kind (required-argument) :type (member :fixed :unknown))
366 ;; The number of values returned, or :Unknown if we don't know. Count may be
367 ;; known when Kind is :Unknown, since we may choose the standard return
368 ;; convention for other reasons.
369 (count (required-argument) :type (or index (member :unknown)))
370 ;; If count isn't :Unknown, then this is a list of the primitive-types of
372 (types () :type list)
373 ;; If kind is :Fixed, then this is the list of the TNs that we return the
375 (locations () :type list))
376 (defprinter (return-info)
382 (defstruct ir2-nlx-info
383 ;; If the kind is :Entry (a lexical exit), then in the home environment, this
384 ;; holds a Value-Cell object containing the unwind block pointer. In the
385 ;; other cases nobody directly references the unwind-block, so we leave this
387 (home nil :type (or tn null))
388 ;; The saved control stack pointer.
389 (save-sp (required-argument) :type tn)
390 ;; The list of dynamic state save TNs.
391 (dynamic-state (list* (make-stack-pointer-tn)
392 (make-dynamic-state-tns))
394 ;; The target label for NLX entry.
395 (target (gen-label) :type label))
396 (defprinter (ir2-nlx-info)
401 ;;; FIXME: Delete? (was commented out in CMU CL)
403 ;;; The Loop structure holds information about a loop.
404 (defstruct (cloop (:conc-name loop-)
406 (:constructor make-loop)
408 ;; The kind of loop that this is. These values are legal:
411 ;; This is the outermost loop structure, and represents all the
412 ;; code in a component.
415 ;; A normal loop with only one entry.
418 ;; A segment of a "strange loop" in a non-reducible flow graph.
419 (kind (required-argument) :type (member :outer :natural :strange))
420 ;; The first and last blocks in the loop. There may be more than one tail,
421 ;; since there may be multiple back branches to the same head.
422 (head nil :type (or cblock null))
423 (tail nil :type list)
424 ;; A list of all the blocks in this loop or its inferiors that have a
425 ;; successor outside of the loop.
426 (exits nil :type list)
427 ;; The loop that this loop is nested within. This is null in the outermost
429 (superior nil :type (or cloop null))
430 ;; A list of the loops nested directly within this one.
431 (inferiors nil :type list)
432 ;; The head of the list of blocks directly within this loop. We must recurse
433 ;; on Inferiors to find all the blocks.
434 (blocks nil :type (or null cblock)))
442 ;;;; VOPs and templates
444 ;;; A VOP is a Virtual Operation. It represents an operation and the
445 ;;; operands to the operation.
446 (defstruct (vop (:constructor make-vop (block node info args results)))
447 ;; VOP-Info structure containing static info about the operation.
448 (info nil :type (or vop-info null))
449 ;; The IR2-Block this VOP is in.
450 (block (required-argument) :type ir2-block)
451 ;; VOPs evaluated after and before this one. Null at the
452 ;; beginning/end of the block, and temporarily during IR2
454 (next nil :type (or vop null))
455 (prev nil :type (or vop null))
456 ;; Heads of the TN-Ref lists for operand TNs, linked using the
458 (args nil :type (or tn-ref null))
459 (results nil :type (or tn-ref null))
460 ;; Head of the list of write refs for each explicitly allocated
461 ;; temporary, linked together using the Across slot.
462 (temps nil :type (or tn-ref null))
463 ;; Head of the list of all TN-refs for references in this VOP,
464 ;; linked by the Next-Ref slot. There will be one entry for each
465 ;; operand and two (a read and a write) for each temporary.
466 (refs nil :type (or tn-ref null))
467 ;; Stuff that is passed uninterpreted from IR2 conversion to
468 ;; codegen. The meaning of this slot is totally dependent on the VOP.
470 ;; Node that generated this VOP, for keeping track of debug info.
471 (node nil :type (or node null))
472 ;; Local-TN bit vector representing the set of TNs live after args
473 ;; are read and before results are written. This is only filled in
474 ;; when VOP-INFO-SAVE-P is non-null.
475 (save-set nil :type (or local-tn-bit-vector null)))
477 (info :prin1 (vop-info-name info))
480 (codegen-info :test codegen-info))
482 ;;; A TN-REF object contains information about a particular reference
483 ;;; to a TN. The information in TN-REFs largely determines how TNs are
485 (defstruct (tn-ref (:constructor make-tn-ref (tn write-p)))
487 (tn (required-argument) :type tn)
488 ;; Is this is a write reference? (as opposed to a read reference)
489 (write-p nil :type boolean)
490 ;; the link for a list running through all TN-Refs for this TN of
491 ;; the same kind (read or write)
492 (next nil :type (or tn-ref null))
493 ;; the VOP where the reference happens, or NIL temporarily
494 (vop nil :type (or vop null))
495 ;; the link for a list of all TN-Refs in VOP, in reverse order of
497 (next-ref nil :type (or tn-ref null))
498 ;; the link for a list of the TN-Refs in VOP of the same kind
499 ;; (argument, result, temp)
500 (across nil :type (or tn-ref null))
501 ;; If true, this is a TN-Ref also in VOP whose TN we would like
502 ;; packed in the same location as our TN. Read and write refs are
503 ;; always paired: Target in the read points to the write, and
505 (target nil :type (or null tn-ref))
506 ;; the load TN allocated for this operand, if any
507 (load-tn nil :type (or tn null)))
511 (vop :test vop :prin1 (vop-info-name (vop-info vop))))
513 ;;; A TEMPLATE object represents a particular IR2 coding strategy for
514 ;;; a known function.
515 (def!struct (template (:constructor nil)
516 #-sb-xc-host (:pure t))
517 ;; The symbol name of this VOP. This is used when printing the VOP
518 ;; and is also used to provide a handle for definition and
520 (name nil :type symbol)
521 ;; A Function-Type describing the arg/result type restrictions. We
522 ;; compute this from the Primitive-Type restrictions to make life
523 ;; easier for IR1 phases that need to anticipate LTN's template
525 (type (required-argument) :type function-type)
526 ;; Lists of restrictions on the argument and result types. A
527 ;; restriction may take several forms:
528 ;; -- The restriction * is no restriction at all.
529 ;; -- A restriction (:OR <primitive-type>*) means that the operand
530 ;; must have one of the specified primitive types.
531 ;; -- A restriction (:CONSTANT <predicate> <type-spec>) means that the
532 ;; argument (not a result) must be a compile-time constant that
533 ;; satisfies the specified predicate function. In this case, the
534 ;; constant value will be passed as an info argument rather than
535 ;; as a normal argument. <type-spec> is a Lisp type specifier for
536 ;; the type tested by the predicate, used when we want to represent
537 ;; the type constraint as a Lisp function type.
539 ;; If Result-Types is :Conditional, then this is an IF-xxx style
540 ;; conditional that yeilds its result as a control transfer. The
541 ;; emit function takes two info arguments: the target label and a
542 ;; boolean flag indicating whether to negate the sense of the test.
543 (arg-types nil :type list)
544 (result-types nil :type (or list (member :conditional)))
545 ;; The primitive type restriction applied to each extra argument or
546 ;; result following the fixed operands. If NIL, no extra
547 ;; args/results are allowed. Otherwise, either * or a (:OR ...) list
548 ;; as described for the {ARG,RESULT}-TYPES.
549 (more-args-type nil :type (or (member nil *) cons))
550 (more-results-type nil :type (or (member nil *) cons))
551 ;; If true, this is a function that is called with no arguments to
552 ;; see whether this template can be emitted. This is used to
553 ;; conditionally compile for different target hardware
554 ;; configuarations (e.g. FP hardware.)
555 (guard nil :type (or function null))
556 ;; The policy under which this template is the best translation.
557 ;; Note that LTN might use this template under other policies if it
558 ;; can't figure our anything better to do.
559 (policy (required-argument) :type policies)
560 ;; The base cost for this template, given optimistic assumptions
561 ;; such as no operand loading, etc.
562 (cost (required-argument) :type index)
563 ;; If true, then a short noun-like phrase describing what this VOP
564 ;; "does", i.e. the implementation strategy. This is for use in
566 (note nil :type (or string null))
567 ;; The number of trailing arguments to VOP or %PRIMITIVE that we
568 ;; bundle into a list and pass into the emit function. This provides
569 ;; a way to pass uninterpreted stuff directly to the code generator.
570 (info-arg-count 0 :type index)
571 ;; A function that emits the VOPs for this template. Arguments:
572 ;; 1] Node for source context.
573 ;; 2] IR2-Block that we place the VOP in.
574 ;; 3] This structure.
575 ;; 4] Head of argument TN-Ref list.
576 ;; 5] Head of result TN-Ref list.
577 ;; 6] If Info-Arg-Count is non-zero, then a list of the magic
580 ;; Two values are returned: the first and last VOP emitted. This vop
581 ;; sequence must be linked into the VOP Next/Prev chain for the
582 ;; block. At least one VOP is always emitted.
583 (emit-function (required-argument) :type function))
584 (defprinter (template)
588 (more-args-type :test more-args-type :prin1 more-args-type)
589 (more-results-type :test more-results-type :prin1 more-results-type)
593 (info-arg-count :test (not (zerop info-arg-count))))
595 ;;; A VOP-INFO object holds the constant information for a given
596 ;;; virtual operation. We include TEMPLATE so that functions with a
597 ;;; direct VOP equivalent can be translated easily.
598 (def!struct (vop-info
600 (:make-load-form-fun ignore-it))
601 ;; Side-effects of this VOP and side-effects that affect the value
603 (effects (required-argument) :type attributes)
604 (affected (required-argument) :type attributes)
605 ;; If true, causes special casing of TNs live after this VOP that
607 ;; -- If T, all such TNs that are allocated in a SC with a defined
608 ;; save-sc will be saved in a TN in the save SC before the VOP
609 ;; and restored after the VOP. This is used by call VOPs. A bit
610 ;; vector representing the live TNs is stored in the VOP-SAVE-SET.
611 ;; -- If :Force-To-Stack, all such TNs will made into :Environment TNs
612 ;; and forced to be allocated in SCs without any save-sc. This is
613 ;; used by NLX entry vops.
614 ;; -- If :Compute-Only, just compute the save set, don't do any saving.
615 ;; This is used to get the live variables for debug info.
616 (save-p nil :type (member t nil :force-to-stack :compute-only))
617 ;; Info for automatic emission of move-arg VOPs by representation
618 ;; selection. If NIL, then do nothing special. If non-null, then
619 ;; there must be a more arg. Each more arg is moved to its passing
620 ;; location using the appropriate representation-specific
621 ;; move-argument VOP. The first (fixed) argument must be the
622 ;; control-stack frame pointer for the frame to move into. The first
623 ;; info arg is the list of passing locations.
625 ;; Additional constraints depend on the value:
631 ;; The second (fixed) arg is the NFP for the called function (from
635 ;; If needed, the old NFP is computed using COMPUTE-OLD-NFP.
636 (move-args nil :type (member nil :full-call :local-call :known-return))
637 ;; A list of sc-vectors representing the loading costs of each fixed
638 ;; argument and result.
639 (arg-costs nil :type list)
640 (result-costs nil :type list)
641 ;; If true, sc-vectors representing the loading costs for any more
643 (more-arg-costs nil :type (or sc-vector null))
644 (more-result-costs nil :type (or sc-vector null))
645 ;; Lists of sc-vectors mapping each SC to the SCs that we can load
646 ;; into. If a SC is directly acceptable to the VOP, then the entry
647 ;; is T. Otherwise, it is a list of the SC numbers of all the SCs
648 ;; that we can load into. This list will be empty if there is no
649 ;; load function which loads from that SC to an SC allowed by the
650 ;; operand SC restriction.
651 (arg-load-scs nil :type list)
652 (result-load-scs nil :type list)
653 ;; If true, a function that is called with the VOP to do operand
654 ;; targeting. This is done by modifiying the TN-Ref-Target slots in
655 ;; the TN-Refs so that they point to other TN-Refs in the same VOP.
656 (target-function nil :type (or null function))
657 ;; A function that emits assembly code for a use of this VOP when it
658 ;; is called with the VOP structure. Null if this VOP has no
659 ;; specified generator (i.e. it exists only to be inherited by other
661 (generator-function nil :type (or function null))
662 ;; A list of things that are used to parameterize an inherited
663 ;; generator. This allows the same generator function to be used for
664 ;; a group of VOPs with similar implementations.
665 (variant nil :type list)
666 ;; The number of arguments and results. Each regular arg/result
667 ;; counts as one, and all the more args/results together count as 1.
668 (num-args 0 :type index)
669 (num-results 0 :type index)
670 ;; Vector of the temporaries the vop needs. See emit-generic-vop in
671 ;; vmdef for information on how the temps are encoded.
673 ;; (The SB-XC-HOST conditionalization on the type is there because
674 ;; it's difficult to dump specialized arrays portably, so on the
675 ;; cross-compilation host we punt by using unspecialized arrays
677 (temps nil :type (or null (specializable-vector (unsigned-byte 16))))
678 ;; The order all the refs for this vop should be put in. Each
679 ;; operand is assigned a number in the following ordering: args,
680 ;; more-args, results, more-results, temps This vector represents
681 ;; the order the operands should be put into in the next-ref link.
683 ;; (The SB-XC-HOST conditionalization on the type is there because
684 ;; it's difficult to dump specialized arrays portably, so on the
685 ;; cross-compilation host we punt by using unspecialized arrays
687 (ref-ordering nil :type (or null (specializable-vector (unsigned-byte 8))))
688 ;; Array of the various targets that should be done. Each element
689 ;; encodes the source ref (shifted 8) and the dest ref index.
690 (targets nil :type (or null (specializable-vector (unsigned-byte 16)))))
694 ;;; copied from docs/internals/retargeting.tex by WHN 19990707:
696 ;;; A Storage Base represents a physical storage resource such as a
697 ;;; register set or stack frame. Storage bases for non-global
698 ;;; resources such as the stack are relativized by the environment
699 ;;; that the TN is allocated in. Packing conflict information is kept
700 ;;; in the storage base, but non-packed storage resources such as
701 ;;; closure environments also have storage bases.
703 ;;; Some storage bases:
704 ;;; General purpose registers
705 ;;; Floating point registers
706 ;;; Boxed (control) stack environment
707 ;;; Unboxed (number) stack environment
708 ;;; Closure environment
710 ;;; A storage class is a potentially arbitrary set of the elements in
711 ;;; a storage base. Although conceptually there may be a hierarchy of
712 ;;; storage classes such as "all registers", "boxed registers", "boxed
713 ;;; scratch registers", this doesn't exist at the implementation
714 ;;; level. Such things can be done by specifying storage classes whose
715 ;;; locations overlap. A TN shouldn't have lots of overlapping SC's as
716 ;;; legal SC's, since time would be wasted repeatedly attempting to
717 ;;; pack in the same locations.
722 ;;; Reg: any register (immediate objects)
723 ;;; Save-Reg: a boxed register near r15 (registers easily saved in a call)
724 ;;; Boxed-Reg: any boxed register (any boxed object)
725 ;;; Unboxed-Reg: any unboxed register (any unboxed object)
726 ;;; Float-Reg, Double-Float-Reg: float in FP register.
727 ;;; Stack: boxed object on the stack (on cstack)
728 ;;; Word: any 32bit unboxed object on nstack.
729 ;;; Double: any 64bit unboxed object on nstack.
731 ;;; The SB structure represents the global information associated with
733 (def!struct (sb (:make-load-form-fun just-dump-it-normally))
734 ;; Name, for printing and reference.
735 (name nil :type symbol)
736 ;; The kind of storage base (which determines the packing
738 (kind :non-packed :type (member :finite :unbounded :non-packed))
739 ;; The number of elements in the SB. If finite, this is the total
740 ;; size. If unbounded, this is the size that the SB is initially
742 (size 0 :type index))
746 ;;; The Finite-SB structure holds information needed by the packing
747 ;;; algorithm for finite SBs.
748 (def!struct (finite-sb (:include sb))
749 ;; The number of locations currently allocated in this SB.
750 (current-size 0 :type index)
751 ;; The last location packed in, used by pack to scatter TNs to
752 ;; prevent a few locations from getting all the TNs, and thus
753 ;; getting overcrowded, reducing the possiblilities for targeting.
754 (last-offset 0 :type index)
755 ;; A vector containing, for each location in this SB, a vector
756 ;; indexed by IR2 block numbers, holding local conflict bit vectors.
757 ;; A TN must not be packed in a given location within a particular
758 ;; block if the LTN number for that TN in that block corresponds to
759 ;; a set bit in the bit-vector.
760 (conflicts '#() :type simple-vector)
761 ;; A vector containing, for each location in this SB, a bit-vector
762 ;; indexed by IR2 block numbers. If the bit corresponding to a block
763 ;; is set, then the location is in use somewhere in the block, and
764 ;; thus has a conflict for always-live TNs.
765 (always-live '#() :type simple-vector)
766 ;; A vector containing the TN currently live in each location in the
767 ;; SB, or NIL if the location is unused. This is used during load-tn pack.
768 (live-tns '#() :type simple-vector)
769 ;; The number of blocks for which the ALWAYS-LIVE and CONFLICTS
770 ;; might not be virgin, and thus must be reinitialized when PACK
771 ;; starts. Less then the length of those vectors when not all of the
772 ;; length was used on the previously packed component.
773 (last-block-count 0 :type index))
775 ;;; the SC structure holds the storage base that storage is allocated
776 ;;; in and information used to select locations within the SB.
778 ;; Name, for printing and reference.
779 (name nil :type symbol)
780 ;; The number used to index SC cost vectors.
781 (number 0 :type sc-number)
782 ;; The storage base that this SC allocates storage from.
783 (sb nil :type (or sb null))
784 ;; The size of elements in this SC, in units of locations in the SB.
785 (element-size 0 :type index)
786 ;; If our SB is finite, a list of the locations in this SC.
787 (locations nil :type list)
788 ;; A list of the alternate (save) SCs for this SC.
789 (alternate-scs nil :type list)
790 ;; A list of the constant SCs that can me moved into this SC.
791 (constant-scs nil :type list)
792 ;; True if this values in this SC needs to be saved across calls.
793 (save-p nil :type boolean)
794 ;; Vectors mapping from SC numbers to information about how to load
795 ;; from the index SC to this one. Move-Functions holds the names of
796 ;; the functions used to do loading, and Load-Costs holds the cost
797 ;; of the corresponding Move-Functions. If loading is impossible,
798 ;; then the entries are NIL. Load-Costs is initialized to have a 0
800 (move-functions (make-array sc-number-limit :initial-element nil)
802 (load-costs (make-array sc-number-limit :initial-element nil)
804 ;; A vector mapping from SC numbers to possibly
805 ;; representation-specific move and coerce VOPs. Each entry is a
806 ;; list of VOP-INFOs for VOPs that move/coerce an object in the
807 ;; index SC's representation into this SC's representation. This
808 ;; vector is filled out with entries for all SCs that can somehow be
809 ;; coerced into this SC, not just those VOPs defined to directly
810 ;; move into this SC (i.e. it allows for operand loading on the move
813 ;; When there are multiple applicable VOPs, the template arg and
814 ;; result type restrictions are used to determine which one to use.
815 ;; The list is sorted by increasing cost, so the first applicable
816 ;; VOP should be used.
818 ;; Move (or move-arg) VOPs with descriptor results shouldn't have
819 ;; TNs wired in the standard argument registers, since there may
820 ;; already be live TNs wired in those locations holding the values
821 ;; that we are setting up for unknown-values return.
822 (move-vops (make-array sc-number-limit :initial-element nil)
824 ;; The costs corresponding to the MOVE-VOPS. Separate because this
825 ;; info is needed at meta-compile time, while the MOVE-VOPs don't
826 ;; exist till load time. If no move is defined, then the entry is
828 (move-costs (make-array sc-number-limit :initial-element nil)
830 ;; Similar to Move-VOPs, except that we only ever use the entries
831 ;; for this SC and its alternates, since we never combine complex
832 ;; representation conversion with argument passing.
833 (move-arg-vops (make-array sc-number-limit :initial-element nil)
835 ;; True if this SC or one of its alternates in in the NUMBER-STACK SB.
836 (number-stack-p nil :type boolean)
837 ;; Alignment restriction. The offset must be an even multiple of this.
838 (alignment 1 :type (and index (integer 1)))
839 ;; A list of locations that we avoid packing in during normal
840 ;; register allocation to ensure that these locations will be free
841 ;; for operand loading. This prevents load-TN packing from thrashing
842 ;; by spilling a lot.
843 (reserve-locations nil :type list))
849 (defstruct (tn (:include sset-element)
850 (:constructor make-random-tn)
851 (:constructor make-tn (number kind primitive-type sc)))
852 ;; The kind of TN this is:
855 ;; A normal, non-constant TN, representing a variable or temporary.
856 ;; Lifetime information is computed so that packing can be done.
859 ;; A TN that has hidden references (debugger or NLX), and thus must be
860 ;; allocated for the duration of the environment it is referenced in.
862 ;; :DEBUG-ENVIRONMENT
863 ;; Like :ENVIRONMENT, but is used for TNs that we want to be able to
864 ;; target to/from and that don't absolutely have to be live
865 ;; everywhere. These TNs are live in all blocks in the environment
866 ;; that don't reference this TN.
869 ;; A TN that implicitly conflicts with all other TNs. No conflict
874 ;; A TN used for saving a :Normal TN across function calls. The
875 ;; lifetime information slots are unitialized: get the original
876 ;; TN our of the SAVE-TN slot and use it for conflicts. Save-Once
877 ;; is like :Save, except that it is only save once at the single
878 ;; writer of the original TN.
881 ;; A TN that was explicitly specified as the save TN for another TN.
882 ;; When we actually get around to doing the saving, this will be
883 ;; changed to :SAVE or :SAVE-ONCE.
886 ;; A load-TN used to compute an argument or result that is
887 ;; restricted to some finite SB. Load TNs don't have any conflict
888 ;; information. Load TN pack uses a special local conflict
889 ;; determination method.
892 ;; Represents a constant, with TN-Leaf a Constant leaf. Lifetime
893 ;; information isn't computed, since the value isn't allocated by
894 ;; pack, but is instead generated as a load at each use. Since
895 ;; lifetime analysis isn't done on :Constant TNs, they don't have
896 ;; Local-Numbers and similar stuff.
899 ;; A special kind of TN used to represent initialization of local
900 ;; call arguments in the caller. It provides another name for the
901 ;; argument TN so that lifetime analysis doesn't get confused by
902 ;; self-recursive calls. Lifetime analysis treats this the same
903 ;; as :NORMAL, but then at the end merges the conflict info into
904 ;; the original TN and replaces all uses of the alias with the
905 ;; original TN. SAVE-TN holds the aliased TN.
906 (kind (required-argument)
907 :type (member :normal :environment :debug-environment
908 :save :save-once :specified-save :load :constant
910 ;; The primitive-type for this TN's value. Null in restricted or
912 (primitive-type nil :type (or primitive-type null))
913 ;; If this TN represents a variable or constant, then this is the
914 ;; corresponding Leaf.
915 (leaf nil :type (or leaf null))
916 ;; Thread that links TNs together so that we can find them.
917 (next nil :type (or tn null))
918 ;; Head of TN-Ref lists for reads and writes of this TN.
919 (reads nil :type (or tn-ref null))
920 (writes nil :type (or tn-ref null))
921 ;; A link we use when building various temporary TN lists.
922 (next* nil :type (or tn null))
923 ;; Some block that contains a reference to this TN, or Nil if we
924 ;; haven't seen any reference yet. If the TN is local, then this is
925 ;; the block it is local to.
926 (local nil :type (or ir2-block null))
927 ;; If a local TN, the block relative number for this TN. Global TNs
928 ;; whose liveness changes within a block are also assigned a local
929 ;; number during the conflicts analysis of that block. If the TN has
930 ;; no local number within the block, then this is Nil.
931 (local-number nil :type (or local-tn-number null))
932 ;; If a local TN, a bit-vector with 1 for the local-number of every
933 ;; TN that we conflict with.
934 (local-conflicts (make-array local-tn-limit :element-type 'bit
936 :type local-tn-bit-vector)
937 ;; Head of the list of Global-Conflicts structures for a global TN.
938 ;; This list is sorted by block number (i.e. reverse DFO), allowing
939 ;; the intersection between the lifetimes for two global TNs to be
940 ;; easily found. If null, then this TN is a local TN.
941 (global-conflicts nil :type (or global-conflicts null))
942 ;; During lifetime analysis, this is used as a pointer into the
943 ;; conflicts chain, for scanning through blocks in reverse DFO.
944 (current-conflict nil)
945 ;; In a :SAVE TN, this is the TN saved. In a :NORMAL or :ENVIRONMENT
946 ;; TN, this is the associated save TN. In TNs with no save TN, this
948 (save-tn nil :type (or tn null))
949 ;; After pack, the SC we packed into. Beforehand, the SC we want to
950 ;; pack into, or null if we don't know.
951 (sc nil :type (or sc null))
952 ;; The offset within the SB that this TN is packed into. This is what
953 ;; indicates that the TN is packed.
954 (offset nil :type (or index null))
955 ;; Some kind of info about how important this TN is.
956 (cost 0 :type fixnum)
957 ;; If a :ENVIRONMENT or :DEBUG-ENVIRONMENT TN, this is the environment that
958 ;; the TN is live throughout.
959 (environment nil :type (or environment null)))
960 (def!method print-object ((tn tn) stream)
961 (print-unreadable-object (tn stream :type t)
962 ;; KLUDGE: The distinction between PRINT-TN and PRINT-OBJECT on TN is
963 ;; not very mnemonic. -- WHN 20000124
964 (print-tn tn stream)))
966 ;;; The GLOBAL-CONFLICTS structure represents the conflicts for global
967 ;;; TNs. Each global TN has a list of these structures, one for each
968 ;;; block that it is live in. In addition to repsenting the result of
969 ;;; lifetime analysis, the global conflicts structure is used during
970 ;;; lifetime analysis to represent the set of TNs live at the start of
972 (defstruct (global-conflicts
973 (:constructor make-global-conflicts (kind tn block number)))
974 ;; The IR2-Block that this structure represents the conflicts for.
975 (block (required-argument) :type ir2-block)
976 ;; Thread running through all the Global-Conflict for Block. This
977 ;; thread is sorted by TN number.
978 (next nil :type (or global-conflicts null))
979 ;; The way that TN is used by Block:
982 ;; The TN is read before it is written. It starts the block live,
983 ;; but is written within the block.
986 ;; The TN is written before any read. It starts the block dead,
987 ;; and need not have a read within the block.
990 ;; The TN is read, but never written. It starts the block live,
991 ;; and is not killed by the block. Lifetime analysis will promote
992 ;; :Read-Only TNs to :Live if they are live at the block end.
995 ;; The TN is not referenced. It is live everywhere in the block.
996 (kind :read-only :type (member :read :write :read-only :live))
997 ;; A local conflicts vector representing conflicts with TNs live in
998 ;; Block. The index for the local TN number of each TN we conflict
999 ;; with in this block is 1. To find the full conflict set, the :Live
1000 ;; TNs for Block must also be included. This slot is not meaningful
1001 ;; when Kind is :Live.
1002 (conflicts (make-array local-tn-limit
1005 :type local-tn-bit-vector)
1006 ;; The TN we are recording conflicts for.
1007 (tn (required-argument) :type tn)
1008 ;; Thread through all the Global-Conflicts for TN.
1009 (tn-next nil :type (or global-conflicts null))
1010 ;; TN's local TN number in Block. :Live TNs don't have local numbers.
1011 (number nil :type (or local-tn-number null)))
1012 (defprinter (global-conflicts)
1016 (number :test number))