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1 ;;;; This file contains stuff for maintaining a database of special
2 ;;;; information about functions known to the compiler. This includes
3 ;;;; semantic information such as side effects and type inference
4 ;;;; functions as well as transforms and IR2 translators.
6 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; more information.
8 ;;;;
9 ;;;; This software is derived from the CMU CL system, which was
10 ;;;; written at Carnegie Mellon University and released into the
11 ;;;; public domain. The software is in the public domain and is
12 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
13 ;;;; files for more information.
19 ;;;; interfaces to defining macros
21 ;;; an IR1 transform
23 ;; the function type which enables this transform.
24 ;;
25 ;; (Note that declaring this :TYPE FUN-TYPE probably wouldn't
26 ;; work because some function types, like (SPECIFIER-TYPE 'FUNCTION0
27 ;; itself, are represented as BUILT-IN-TYPE, and at least as of
28 ;; sbcl-0.pre7.54 or so, that's inconsistent with being a
29 ;; FUN-TYPE.)
31 ;; the transformation function. Takes the COMBINATION node and
32 ;; returns a lambda expression, or throws out.
34 ;; string used in efficiency notes
36 ;; T if we should emit a failure note even if SPEED=INHIBIT-WARNINGS.
38 ;; A function with NODE as an argument that checks wheteher the
39 ;; transform applies in its policy.
40 ;; It used to be checked in the FUNCTION body but it would produce
41 ;; notes about failed transformation due to types even though it
42 ;; wouldn't have been applied with the right types anyway,
43 ;; or if another transform could be applied with the right policy.
48 ;;; Grab the FUN-INFO and enter the function, replacing any old
49 ;;; one with the same type and note.
66 :important important
69 name))
71 ;;; Make a FUN-INFO structure with the specified type, attributes
72 ;;; and optimizers.
74 &key derive-type optimizer destroyed-constant-args result-arg
75 overwrite-fndb-silently
76 foldable-call-check
77 callable-check
78 call-type-deriver
79 functional-args)
85 ;; This is handled as an error because it's generally a bad
86 ;; thing to blow away all the old optimization stuff. It's
87 ;; also a potential source of sneaky bugs:
88 ;; DEFKNOWN FOO
89 ;; DEFTRANSFORM FOO
90 ;; DEFKNOWN FOO ; possibly hidden inside some macroexpansion
91 ;; ; Now the DEFTRANSFORM doesn't exist in the target Lisp.
92 ;; However, it's continuable because it might be useful to do
93 ;; it when testing new optimization stuff interactively.
95 "~@<overwriting old FUN-INFO ~2I~_~S ~I~_for ~S~:>"
96 old-fun-info name))))
102 :derive-type derive-type
103 :optimizer optimizer
104 :destroyed-constant-args destroyed-constant-args
105 :result-arg result-arg
106 :foldable-call-check foldable-call-check
107 :callable-check callable-check
108 :call-type-deriver call-type-deriver
112 location)
114 names)
116 ;;; Return the FUN-INFO for NAME or die trying.
120 \f
121 ;;;; generic type inference methods
123 ;;; Derive the type to be the type of the xxx'th arg. This can normally
124 ;;; only be done when the result value is that argument.
134 ;;; Derive the result type according to the float contagion rules, but
135 ;;; always return a float. This is used for irrational functions that
136 ;;; preserve realness of their arguments.
144 ;; Preserve all the list types without dragging
145 ;; (cons (eql 10)) stuff in.
151 cons-type)
154 null-type)
156 list-type))))
158 ;;; Return a closure usable as a derive-type method for accessing the
159 ;;; N'th argument. If arg is a list, result is a list. If arg is a
160 ;;; vector, result is a vector with the same element type.
162 preserve-vector-type)
171 nil)
173 type)
180 simplified)
181 simplified)))))))))
183 ;;; Derive the type to be the type specifier which is the Nth arg.
191 ;;; Derive the type to be the type specifier which is the Nth arg,
192 ;;; with the additional restriptions noted in the CLHS for STRING and
193 ;;; SIMPLE-STRING, defined to specialize on CHARACTER, and for VECTOR
194 ;;; (under the page for MAKE-SEQUENCE).
195 ;;; At present this is used to derive the output type of CONCATENATE,
196 ;;; MAKE-SEQUENCE, and MERGE. Two things seem slightly amiss:
197 ;;; 1. The sequence type actually produced might not be exactly that specified.
198 ;;; (TYPE-OF (MAKE-SEQUENCE '(AND (NOT SIMPLE-ARRAY) (VECTOR BIT)) 9))
199 ;;; => (SIMPLE-BIT-VECTOR 9)
200 ;;; 2. Because we *know* that a hairy array won't be produced,
201 ;;; why does derivation preserve the non-simpleness, if so specified?
212 lspecifier
218 lspecifier
225 ctype)
238 ctype))))))))))
245 ;;; FIXME: bad name (first because it uses 1-based indexing; second
246 ;;; because it doesn't get the nth constant arguments)
259 ;;; FIXME: a number of the sequence functions not only do not destroy
260 ;;; their argument if it is empty, but also leave it alone if :start
261 ;;; and :end bound a null sequence, or if :count is 0. This test is a
262 ;;; bit complicated to implement, verging on the impossible, but for
263 ;;; extra points (fill #\1 "abc" :start 0 :end 0) should not cause a
264 ;;; warning.
292 null-type))
293 ;; (READ-elt stream nil <x>) returns (OR (EQL <x>) elt-type)
295 element-type)
296 ;; If eof-error is unsupplied, or was but couldn't be nil
297 element-type)))
300 unexceptional-type))))
302 ;;; Return MAX MIN
308 ;; This can deal with just enough hair to handle type STRING,
309 ;; but might be made to use GENERIC-ABSTRACT-TYPE-FUNCTION
310 ;; if we really want to be more clever.
325 ;; If type derivation were able to notice that non-simple arrays can
326 ;; be mutated (changing the type), we could safely use LVAR-TYPE on
327 ;; any vector type. But it doesn't notice.
328 ;; We could use LVAR-CONSERVATIVE-TYPE to get a conservative answer.
329 ;; However that's probably not an important use, so the above
330 ;; logic restricts itself to simple arrays.
348 ;;; This used to be done in DEFOPTIMIZER DERIVE-TYPE, but
349 ;;; ASSERT-CALL-TYPE already asserts the ARRAY type, so it gets an extra
350 ;;; assertion that may not get eliminated and requires extra work.
359 while next