1 ;;;; type testing and checking VOPs for the x86 VM
3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
14 ;;;; test generation utilities
16 ;;; Emit the most compact form of the test immediate instruction,
17 ;;; using an 8 bit test when the immediate is only 8 bits and the
18 ;;; value is one of the four low registers (eax, ebx, ecx, edx) or the
20 (defun generate-fixnum-test (value)
21 (let ((offset (tn-offset value)))
22 (cond ((and (sc-is value any-reg descriptor-reg)
23 (or (= offset eax-offset) (= offset ebx-offset)
24 (= offset ecx-offset) (= offset edx-offset)))
25 (inst test (make-random-tn :kind :normal
26 :sc (sc-or-lose 'byte-reg)
29 ((sc-is value control-stack)
30 (inst test (make-ea :byte :base ebp-tn
31 :disp (- (* (1+ offset) n-word-bytes)))
34 (inst test value 3)))))
36 (defun %test-fixnum (value target not-p)
37 (generate-fixnum-test value)
38 (inst jmp (if not-p :nz :z) target))
40 (defun %test-fixnum-and-headers (value target not-p headers)
41 (let ((drop-through (gen-label)))
42 (generate-fixnum-test value)
43 (inst jmp :z (if not-p drop-through target))
44 (%test-headers value target not-p nil headers drop-through)))
46 (defun %test-immediate (value target not-p immediate)
47 ;; Code a single instruction byte test if possible.
48 (let ((offset (tn-offset value)))
49 (cond ((and (sc-is value any-reg descriptor-reg)
50 (or (= offset eax-offset) (= offset ebx-offset)
51 (= offset ecx-offset) (= offset edx-offset)))
52 (inst cmp (make-random-tn :kind :normal
53 :sc (sc-or-lose 'byte-reg)
58 (inst cmp al-tn immediate))))
59 (inst jmp (if not-p :ne :e) target))
61 (defun %test-lowtag (value target not-p lowtag &optional al-loaded)
64 (inst and al-tn lowtag-mask))
65 (inst cmp al-tn lowtag)
66 (inst jmp (if not-p :ne :e) target))
68 (defun %test-lowtag-and-headers (value target not-p lowtag function-p headers)
69 (let ((drop-through (gen-label)))
70 (%test-lowtag value (if not-p drop-through target) nil lowtag)
71 (%test-headers value target not-p function-p headers drop-through t)))
74 (defun %test-headers (value target not-p function-p headers
75 &optional (drop-through (gen-label)) al-loaded)
76 (let ((lowtag (if function-p fun-pointer-lowtag other-pointer-lowtag)))
77 (multiple-value-bind (equal less-or-equal when-true when-false)
78 ;; EQUAL and LESS-OR-EQUAL are the conditions for branching to TARGET.
79 ;; WHEN-TRUE and WHEN-FALSE are the labels to branch to when we know
80 ;; it's true and when we know it's false respectively.
82 (values :ne :a drop-through target)
83 (values :e :na target drop-through))
84 (%test-lowtag value when-false t lowtag al-loaded)
85 (inst mov al-tn (make-ea :byte :base value :disp (- lowtag)))
86 (do ((remaining headers (cdr remaining)))
88 (let ((header (car remaining))
89 (last (null (cdr remaining))))
92 (inst cmp al-tn header)
94 (inst jmp equal target)
95 (inst jmp :e when-true)))
97 (let ((start (car header))
99 (unless (= start bignum-widetag)
100 (inst cmp al-tn start)
101 (inst jmp :b when-false)) ; was :l
104 (inst jmp less-or-equal target)
105 (inst jmp :be when-true))))))) ; was :le
106 (emit-label drop-through))))
109 ;;;; type checking and testing
111 (define-vop (check-type)
112 (:args (value :target result :scs (any-reg descriptor-reg)))
113 (:results (result :scs (any-reg descriptor-reg)))
114 (:temporary (:sc unsigned-reg :offset eax-offset :to (:result 0)) eax)
117 (:save-p :compute-only))
119 (define-vop (type-predicate)
120 (:args (value :scs (any-reg descriptor-reg)))
121 (:temporary (:sc unsigned-reg :offset eax-offset) eax)
125 (:policy :fast-safe))
127 ;;; simpler VOP that don't need a temporary register
128 (define-vop (simple-check-type)
129 (:args (value :target result :scs (any-reg descriptor-reg)))
130 (:results (result :scs (any-reg descriptor-reg)
131 :load-if (not (and (sc-is value any-reg descriptor-reg)
132 (sc-is result control-stack)))))
134 (:save-p :compute-only))
136 (define-vop (simple-type-predicate)
137 (:args (value :scs (any-reg descriptor-reg control-stack)))
140 (:policy :fast-safe))
142 (defun cost-to-test-types (type-codes)
143 (+ (* 2 (length type-codes))
144 (if (> (apply #'max type-codes) lowtag-limit) 7 2)))
146 (defmacro !define-type-vops (pred-name check-name ptype error-code
148 &key (variant nil variant-p) &allow-other-keys)
149 ;; KLUDGE: UGH. Why do we need this eval? Can't we put this in the
151 (let* ((cost (cost-to-test-types (mapcar #'eval type-codes)))
152 (prefix (if variant-p
153 (concatenate 'string (string variant) "-")
157 `((define-vop (,pred-name ,(intern (concatenate 'string prefix "TYPE-PREDICATE")))
158 (:translate ,pred-name)
160 (test-type value target not-p (,@type-codes))))))
162 `((define-vop (,check-name ,(intern (concatenate 'string prefix "CHECK-TYPE")))
165 (generate-error-code vop ,error-code value)))
166 (test-type value err-lab t (,@type-codes))
167 (move result value))))))
169 `((primitive-type-vop ,check-name (:check) ,ptype))))))
171 ;;;; other integer ranges
173 ;;; A (SIGNED-BYTE 32) can be represented with either fixnum or a bignum with
174 ;;; exactly one digit.
176 (define-vop (signed-byte-32-p type-predicate)
177 (:translate signed-byte-32-p)
179 (multiple-value-bind (yep nope)
181 (values not-target target)
182 (values target not-target))
183 (generate-fixnum-test value)
186 (inst and al-tn lowtag-mask)
187 (inst cmp al-tn other-pointer-lowtag)
189 (loadw eax-tn value 0 other-pointer-lowtag)
190 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
191 (inst jmp (if not-p :ne :e) target))
194 (define-vop (check-signed-byte-32 check-type)
196 (let ((nope (generate-error-code vop
197 object-not-signed-byte-32-error
199 (generate-fixnum-test value)
202 (inst and al-tn lowtag-mask)
203 (inst cmp al-tn other-pointer-lowtag)
205 (loadw eax-tn value 0 other-pointer-lowtag)
206 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
209 (move result value)))
211 ;;; An (unsigned-byte 32) can be represented with either a positive
212 ;;; fixnum, a bignum with exactly one positive digit, or a bignum with
213 ;;; exactly two digits and the second digit all zeros.
214 (define-vop (unsigned-byte-32-p type-predicate)
215 (:translate unsigned-byte-32-p)
217 (let ((not-target (gen-label))
218 (single-word (gen-label))
219 (fixnum (gen-label)))
220 (multiple-value-bind (yep nope)
222 (values not-target target)
223 (values target not-target))
225 (generate-fixnum-test value)
229 ;; If not, is it an other pointer?
230 (inst and al-tn lowtag-mask)
231 (inst cmp al-tn other-pointer-lowtag)
234 (loadw eax-tn value 0 other-pointer-lowtag)
236 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
237 (inst jmp :e single-word)
238 ;; If it's other than two, we can't be an (unsigned-byte 32)
239 (inst cmp eax-tn (+ (ash 2 n-widetag-bits) bignum-widetag))
241 ;; Get the second digit.
242 (loadw eax-tn value (1+ bignum-digits-offset) other-pointer-lowtag)
243 ;; All zeros, its an (unsigned-byte 32).
244 (inst or eax-tn eax-tn)
248 (emit-label single-word)
249 ;; Get the single digit.
250 (loadw eax-tn value bignum-digits-offset other-pointer-lowtag)
252 ;; positive implies (unsigned-byte 32).
254 (inst or eax-tn eax-tn)
255 (inst jmp (if not-p :s :ns) target)
257 (emit-label not-target)))))
259 (define-vop (check-unsigned-byte-32 check-type)
262 (generate-error-code vop object-not-unsigned-byte-32-error value))
265 (single-word (gen-label)))
268 (generate-fixnum-test value)
272 ;; If not, is it an other pointer?
273 (inst and al-tn lowtag-mask)
274 (inst cmp al-tn other-pointer-lowtag)
277 (loadw eax-tn value 0 other-pointer-lowtag)
279 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
280 (inst jmp :e single-word)
281 ;; If it's other than two, we can't be an (unsigned-byte 32)
282 (inst cmp eax-tn (+ (ash 2 n-widetag-bits) bignum-widetag))
284 ;; Get the second digit.
285 (loadw eax-tn value (1+ bignum-digits-offset) other-pointer-lowtag)
286 ;; All zeros, its an (unsigned-byte 32).
287 (inst or eax-tn eax-tn)
291 (emit-label single-word)
292 ;; Get the single digit.
293 (loadw eax-tn value bignum-digits-offset other-pointer-lowtag)
295 ;; positive implies (unsigned-byte 32).
297 (inst or eax-tn eax-tn)
301 (move result value))))
303 ;;;; list/symbol types
305 ;;; symbolp (or symbol (eq nil))
306 ;;; consp (and list (not (eq nil)))
308 (define-vop (symbolp type-predicate)
311 (let ((is-symbol-label (if not-p drop-thru target)))
312 (inst cmp value nil-value)
313 (inst jmp :e is-symbol-label)
314 (test-type value target not-p (symbol-header-widetag)))
317 (define-vop (check-symbol check-type)
319 (let ((error (generate-error-code vop object-not-symbol-error value)))
320 (inst cmp value nil-value)
321 (inst jmp :e drop-thru)
322 (test-type value error t (symbol-header-widetag)))
324 (move result value)))
326 (define-vop (consp type-predicate)
329 (let ((is-not-cons-label (if not-p target drop-thru)))
330 (inst cmp value nil-value)
331 (inst jmp :e is-not-cons-label)
332 (test-type value target not-p (list-pointer-lowtag)))
335 (define-vop (check-cons check-type)
337 (let ((error (generate-error-code vop object-not-cons-error value)))
338 (inst cmp value nil-value)
340 (test-type value error t (list-pointer-lowtag))
341 (move result value))))