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 ;;; FIXME: DEF-TYPE-VOPS and DEF-SIMPLE-TYPE-VOPS are only used in
143 ;;; this file, so they should be in the EVAL-WHEN above, or otherwise
144 ;;; tweaked so that they don't appear in the target system.
146 (defun cost-to-test-types (type-codes)
147 (+ (* 2 (length type-codes))
148 (if (> (apply #'max type-codes) lowtag-limit) 7 2)))
150 (defmacro !define-type-vops (pred-name check-name ptype error-code
152 &key (variant nil variant-p))
153 ;; KLUDGE: UGH. Why do we need this eval? Can't we put this in the
155 (let* ((cost (cost-to-test-types (mapcar #'eval type-codes)))
156 (prefix (if variant-p
157 (concatenate 'string (string variant) "-")
161 `((define-vop (,pred-name ,(intern (concatenate 'string prefix "TYPE-PREDICATE")))
162 (:translate ,pred-name)
164 (test-type value target not-p ,@type-codes)))))
166 `((define-vop (,check-name ,(intern (concatenate 'string prefix "CHECK-TYPE")))
169 (generate-error-code vop ,error-code value)))
170 (test-type value err-lab t ,@type-codes)
171 (move result value))))))
173 `((primitive-type-vop ,check-name (:check) ,ptype))))))
175 ;;;; other integer ranges
177 ;;; A (SIGNED-BYTE 32) can be represented with either fixnum or a bignum with
178 ;;; exactly one digit.
180 (define-vop (signed-byte-32-p type-predicate)
181 (:translate signed-byte-32-p)
183 (multiple-value-bind (yep nope)
185 (values not-target target)
186 (values target not-target))
187 (generate-fixnum-test value)
190 (inst and al-tn lowtag-mask)
191 (inst cmp al-tn other-pointer-lowtag)
193 (loadw eax-tn value 0 other-pointer-lowtag)
194 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
195 (inst jmp (if not-p :ne :e) target))
198 (define-vop (check-signed-byte-32 check-type)
200 (let ((nope (generate-error-code vop
201 object-not-signed-byte-32-error
203 (generate-fixnum-test value)
206 (inst and al-tn lowtag-mask)
207 (inst cmp al-tn other-pointer-lowtag)
209 (loadw eax-tn value 0 other-pointer-lowtag)
210 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
213 (move result value)))
215 ;;; An (unsigned-byte 32) can be represented with either a positive
216 ;;; fixnum, a bignum with exactly one positive digit, or a bignum with
217 ;;; exactly two digits and the second digit all zeros.
218 (define-vop (unsigned-byte-32-p type-predicate)
219 (:translate unsigned-byte-32-p)
221 (let ((not-target (gen-label))
222 (single-word (gen-label))
223 (fixnum (gen-label)))
224 (multiple-value-bind (yep nope)
226 (values not-target target)
227 (values target not-target))
229 (generate-fixnum-test value)
233 ;; If not, is it an other pointer?
234 (inst and al-tn lowtag-mask)
235 (inst cmp al-tn other-pointer-lowtag)
238 (loadw eax-tn value 0 other-pointer-lowtag)
240 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
241 (inst jmp :e single-word)
242 ;; If it's other than two, we can't be an (unsigned-byte 32)
243 (inst cmp eax-tn (+ (ash 2 n-widetag-bits) bignum-widetag))
245 ;; Get the second digit.
246 (loadw eax-tn value (1+ bignum-digits-offset) other-pointer-lowtag)
247 ;; All zeros, its an (unsigned-byte 32).
248 (inst or eax-tn eax-tn)
252 (emit-label single-word)
253 ;; Get the single digit.
254 (loadw eax-tn value bignum-digits-offset other-pointer-lowtag)
256 ;; positive implies (unsigned-byte 32).
258 (inst or eax-tn eax-tn)
259 (inst jmp (if not-p :s :ns) target)
261 (emit-label not-target)))))
263 (define-vop (check-unsigned-byte-32 check-type)
266 (generate-error-code vop object-not-unsigned-byte-32-error value))
269 (single-word (gen-label)))
272 (generate-fixnum-test value)
276 ;; If not, is it an other pointer?
277 (inst and al-tn lowtag-mask)
278 (inst cmp al-tn other-pointer-lowtag)
281 (loadw eax-tn value 0 other-pointer-lowtag)
283 (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag))
284 (inst jmp :e single-word)
285 ;; If it's other than two, we can't be an (unsigned-byte 32)
286 (inst cmp eax-tn (+ (ash 2 n-widetag-bits) bignum-widetag))
288 ;; Get the second digit.
289 (loadw eax-tn value (1+ bignum-digits-offset) other-pointer-lowtag)
290 ;; All zeros, its an (unsigned-byte 32).
291 (inst or eax-tn eax-tn)
295 (emit-label single-word)
296 ;; Get the single digit.
297 (loadw eax-tn value bignum-digits-offset other-pointer-lowtag)
299 ;; positive implies (unsigned-byte 32).
301 (inst or eax-tn eax-tn)
305 (move result value))))
307 ;;;; list/symbol types
309 ;;; symbolp (or symbol (eq nil))
310 ;;; consp (and list (not (eq nil)))
312 (define-vop (symbolp type-predicate)
315 (let ((is-symbol-label (if not-p drop-thru target)))
316 (inst cmp value nil-value)
317 (inst jmp :e is-symbol-label)
318 (test-type value target not-p symbol-header-widetag))
321 (define-vop (check-symbol check-type)
323 (let ((error (generate-error-code vop object-not-symbol-error value)))
324 (inst cmp value nil-value)
325 (inst jmp :e drop-thru)
326 (test-type value error t symbol-header-widetag))
328 (move result value)))
330 (define-vop (consp type-predicate)
333 (let ((is-not-cons-label (if not-p target drop-thru)))
334 (inst cmp value nil-value)
335 (inst jmp :e is-not-cons-label)
336 (test-type value target not-p list-pointer-lowtag))
339 (define-vop (check-cons check-type)
341 (let ((error (generate-error-code vop object-not-cons-error value)))
342 (inst cmp value nil-value)
344 (test-type value error t list-pointer-lowtag)
345 (move result value))))