1 ;;;; the x86 VM definition of operand loading/saving and the MOVE vop
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 (define-move-fun (load-immediate 1) (vop x y)
16 (any-reg descriptor-reg))
17 (let ((val (encode-value-if-immediate x)))
22 (define-move-fun (load-number 1) (vop x y)
23 ((immediate) (signed-reg unsigned-reg))
24 (let ((val (tn-value x)))
29 (define-move-fun (load-character 1) (vop x y)
30 ((immediate) (character-reg))
31 (inst mov y (char-code (tn-value x))))
33 (define-move-fun (load-system-area-pointer 1) (vop x y)
34 ((immediate) (sap-reg))
35 (inst mov y (sap-int (tn-value x))))
37 (define-move-fun (load-constant 5) (vop x y)
38 ((constant) (descriptor-reg any-reg))
41 (define-move-fun (load-stack 5) (vop x y)
42 ((control-stack) (any-reg descriptor-reg)
43 (character-stack) (character-reg)
45 (signed-stack) (signed-reg)
46 (unsigned-stack) (unsigned-reg))
49 (define-move-fun (store-stack 5) (vop x y)
50 ((any-reg descriptor-reg) (control-stack)
51 (character-reg) (character-stack)
53 (signed-reg) (signed-stack)
54 (unsigned-reg) (unsigned-stack))
59 (:args (x :scs (any-reg descriptor-reg immediate) :target y
60 :load-if (not (location= x y))))
61 (:results (y :scs (any-reg descriptor-reg)
63 (not (or (location= x y)
64 (and (sc-is x any-reg descriptor-reg immediate)
65 (sc-is y control-stack))))))
69 (if (and (sc-is x immediate)
70 (sc-is y any-reg descriptor-reg control-stack))
71 (let ((val (encode-value-if-immediate x)))
72 (if (and (zerop val) (sc-is y any-reg descriptor-reg))
77 (define-move-vop move :move
78 (any-reg descriptor-reg immediate)
79 (any-reg descriptor-reg))
81 ;;; Make MOVE the check VOP for T so that type check generation
82 ;;; doesn't think it is a hairy type. This also allows checking of a
83 ;;; few of the values in a continuation to fall out.
84 (primitive-type-vop move (:check) t)
86 ;;; The MOVE-ARG VOP is used for moving descriptor values into
87 ;;; another frame for argument or known value passing.
89 ;;; Note: It is not going to be possible to move a constant directly
90 ;;; to another frame, except if the destination is a register and in
91 ;;; this case the loading works out.
92 (define-vop (move-arg)
93 (:args (x :scs (any-reg descriptor-reg immediate) :target y
94 :load-if (not (and (sc-is y any-reg descriptor-reg)
95 (sc-is x control-stack))))
97 :load-if (not (sc-is y any-reg descriptor-reg))))
101 ((any-reg descriptor-reg)
102 (if (sc-is x immediate)
103 (let ((val (encode-value-if-immediate x)))
109 (let ((frame-offset (if (= (tn-offset fp) esp-offset)
113 (frame-word-offset (tn-offset y)))))
114 (storew (encode-value-if-immediate x) fp frame-offset))))))
116 (define-move-vop move-arg :move-arg
117 (any-reg descriptor-reg)
118 (any-reg descriptor-reg))
122 ;;; This VOP exists just to begin the lifetime of a TN that couldn't
123 ;;; be written legally due to a type error. An error is signalled
124 ;;; before this VOP is so we don't need to do anything (not that there
125 ;;; would be anything sensible to do anyway.)
126 (define-vop (illegal-move)
131 (:save-p :compute-only)
133 (error-call vop object-not-type-error x type)))
135 ;;;; moves and coercions
137 ;;; These MOVE-TO-WORD VOPs move a tagged integer to a raw full-word
138 ;;; representation. Similarly, the MOVE-FROM-WORD VOPs converts a raw
139 ;;; integer to a tagged bignum or fixnum.
141 ;;; Arg is a fixnum, so just shift it. We need a type restriction
142 ;;; because some possible arg SCs (control-stack) overlap with
143 ;;; possible bignum arg SCs.
144 (define-vop (move-to-word/fixnum)
145 (:args (x :scs (any-reg descriptor-reg) :target y
146 :load-if (not (location= x y))))
147 (:results (y :scs (signed-reg unsigned-reg)
148 :load-if (not (location= x y))))
149 (:arg-types tagged-num)
150 (:note "fixnum untagging")
154 (define-move-vop move-to-word/fixnum :move
155 (any-reg descriptor-reg) (signed-reg unsigned-reg))
157 ;;; Arg is a non-immediate constant, load it.
158 (define-vop (move-to-word-c)
159 (:args (x :scs (constant)))
160 (:results (y :scs (signed-reg unsigned-reg)))
161 (:note "constant load")
163 (inst mov y (tn-value x))))
164 (define-move-vop move-to-word-c :move
165 (constant) (signed-reg unsigned-reg))
168 ;;; Arg is a fixnum or bignum, figure out which and load if necessary.
169 (define-vop (move-to-word/integer)
170 (:args (x :scs (descriptor-reg) :target eax))
171 (:results (y :scs (signed-reg unsigned-reg)))
172 (:note "integer to untagged word coercion")
173 (:temporary (:sc unsigned-reg :offset eax-offset
174 :from (:argument 0) :to (:result 0) :target y) eax)
179 (loadw y eax bignum-digits-offset other-pointer-lowtag)
185 (define-move-vop move-to-word/integer :move
186 (descriptor-reg) (signed-reg unsigned-reg))
189 ;;; Result is a fixnum, so we can just shift. We need the result type
190 ;;; restriction because of the control-stack ambiguity noted above.
191 (define-vop (move-from-word/fixnum)
192 (:args (x :scs (signed-reg unsigned-reg) :target y
193 :load-if (not (location= x y))))
194 (:results (y :scs (any-reg descriptor-reg)
195 :load-if (not (location= x y))))
196 (:result-types tagged-num)
197 (:note "fixnum tagging")
199 (cond ((and (sc-is x signed-reg unsigned-reg)
200 (not (location= x y)))
201 ;; Uses 7 bytes, but faster on the Pentium
202 (inst lea y (make-ea :dword :index x :scale 4)))
204 ;; Uses: If x is a reg 2 + 3; if x = y uses only 3 bytes
207 (define-move-vop move-from-word/fixnum :move
208 (signed-reg unsigned-reg) (any-reg descriptor-reg))
210 ;;; Result may be a bignum, so we have to check. Use a worst-case cost
211 ;;; to make sure people know they may be number consing.
213 ;;; KLUDGE: I assume this is suppressed in favor of the "faster inline
214 ;;; version" below. (See also mysterious comment "we don't want a VOP
215 ;;; on this one" on DEFINE-ASSEMBLY-ROUTINE (MOVE-FROM-SIGNED) in
216 ;;; "src/assembly/x86/alloc.lisp".) -- WHN 19990916
218 (define-vop (move-from-signed)
219 (:args (x :scs (signed-reg unsigned-reg) :target eax))
220 (:temporary (:sc unsigned-reg :offset eax-offset :from (:argument 0)) eax)
221 (:temporary (:sc unsigned-reg :offset ebx-offset :to (:result 0) :target y)
223 (:temporary (:sc unsigned-reg :offset ecx-offset
224 :from (:argument 0) :to (:result 0)) ecx)
226 (:results (y :scs (any-reg descriptor-reg)))
227 (:note "signed word to integer coercion")
230 (inst call (make-fixup 'move-from-signed :assembly-routine))
232 ;;; Faster inline version,
233 ;;; KLUDGE: Do we really want the faster inline version? It's sorta big.
234 ;;; It is nice that it doesn't use any temporaries, though. -- WHN 19990916
235 (define-vop (move-from-signed)
236 (:args (x :scs (signed-reg unsigned-reg) :to :result))
237 (:results (y :scs (any-reg descriptor-reg) :from :argument))
238 (:note "signed word to integer coercion")
241 (aver (not (location= x y)))
242 (let ((bignum (gen-label))
250 ;; KLUDGE: The sequence above leaves a DESCRIPTOR-REG Y in a
251 ;; non-descriptor state for a while. Does that matter? Does it
252 ;; matter in GENGC but not in GENCGC? Is this written down
256 ;; Also, the sequence above seems rather twisty. Why not something
257 ;; more obvious along the lines of
259 ;; inst tst x #xc0000000
260 ;; inst jmp :nz bignum
264 (assemble (*elsewhere*)
266 (with-fixed-allocation
267 (y bignum-widetag (+ bignum-digits-offset 1) node)
268 (storew x y bignum-digits-offset other-pointer-lowtag))
270 (define-move-vop move-from-signed :move
271 (signed-reg) (descriptor-reg))
273 ;;; Check for fixnum, and possibly allocate one or two word bignum
274 ;;; result. Use a worst-case cost to make sure people know they may be
277 (define-vop (move-from-unsigned)
278 (:args (x :scs (signed-reg unsigned-reg) :target eax))
279 (:temporary (:sc unsigned-reg :offset eax-offset :from (:argument 0)) eax)
280 (:temporary (:sc unsigned-reg :offset ebx-offset :to (:result 0) :target y)
282 (:temporary (:sc unsigned-reg :offset ecx-offset
283 :from (:argument 0) :to (:result 0)) ecx)
285 (:results (y :scs (any-reg descriptor-reg)))
286 (:note "unsigned word to integer coercion")
289 (inst call (make-fixup 'move-from-unsigned :assembly-routine))
291 ;;; Faster inline version.
292 ;;; KLUDGE: Do we really want the faster inline version? It seems awfully big..
293 ;;; If we really want speed, most likely it's only important in the non-consing
294 ;;; case, so how about about making the *ELSEWHERE* stuff into a subroutine? --
296 (define-vop (move-from-unsigned)
297 (:args (x :scs (signed-reg unsigned-reg) :to :save))
298 (:temporary (:sc unsigned-reg) alloc)
299 (:results (y :scs (any-reg descriptor-reg)))
301 (:note "unsigned word to integer coercion")
303 (aver (not (location= x y)))
304 (aver (not (location= x alloc)))
305 (aver (not (location= y alloc)))
306 (let ((bignum (gen-label))
308 (one-word-bignum (gen-label))
310 (inst test x #xe0000000)
311 (inst jmp :nz bignum)
313 (inst lea y (make-ea :dword :index x :scale 4)) ; Faster but bigger.
318 (assemble (*elsewhere*)
320 ;; Note: As on the mips port, space for a two word bignum is
321 ;; always allocated and the header size is set to either one
322 ;; or two words as appropriate.
323 (inst jmp :ns one-word-bignum)
325 (inst mov y (logior (ash (1- (+ bignum-digits-offset 2))
329 (emit-label one-word-bignum)
330 (inst mov y (logior (ash (1- (+ bignum-digits-offset 1))
335 (allocation alloc (pad-data-block (+ bignum-digits-offset 2)) node)
337 (inst lea y (make-ea :byte :base alloc :disp other-pointer-lowtag))
338 (storew x y bignum-digits-offset other-pointer-lowtag))
340 (define-move-vop move-from-unsigned :move
341 (unsigned-reg) (descriptor-reg))
343 ;;; Move untagged numbers.
344 (define-vop (word-move)
345 (:args (x :scs (signed-reg unsigned-reg) :target y
346 :load-if (not (location= x y))))
347 (:results (y :scs (signed-reg unsigned-reg)
349 (not (or (location= x y)
350 (and (sc-is x signed-reg unsigned-reg)
351 (sc-is y signed-stack unsigned-stack))))))
354 (:note "word integer move")
357 (define-move-vop word-move :move
358 (signed-reg unsigned-reg) (signed-reg unsigned-reg))
360 ;;; Move untagged number arguments/return-values.
361 (define-vop (move-word-arg)
362 (:args (x :scs (signed-reg unsigned-reg) :target y)
363 (fp :scs (any-reg) :load-if (not (sc-is y sap-reg))))
365 (:note "word integer argument move")
368 ((signed-reg unsigned-reg)
370 ((signed-stack unsigned-stack)
371 (if (= (tn-offset fp) esp-offset)
372 (storew x fp (tn-offset y)) ; c-call
373 (storew x fp (frame-word-offset (tn-offset y))))))))
374 (define-move-vop move-word-arg :move-arg
375 (descriptor-reg any-reg signed-reg unsigned-reg) (signed-reg unsigned-reg))
377 ;;; Use standard MOVE-ARG and coercion to move an untagged number
378 ;;; to a descriptor passing location.
379 (define-move-vop move-arg :move-arg
380 (signed-reg unsigned-reg) (any-reg descriptor-reg))