1 ;;;; various primitive memory access 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 ;;;; data object ref/set stuff
17 (:args (object :scs (descriptor-reg)))
18 (:info name offset lowtag)
20 (:results (result :scs (descriptor-reg any-reg)))
22 (loadw result object offset lowtag)))
24 (define-vop (set-slot)
25 (:args (object :scs (descriptor-reg))
26 (value :scs (descriptor-reg any-reg immediate)))
27 (:temporary (:sc descriptor-reg) temp)
28 (:info name offset lowtag)
32 (if (sc-is value immediate)
33 (let ((val (tn-value value)))
34 (move-immediate (make-ea :qword
36 :disp (- (* offset n-word-bytes)
42 (+ nil-value (static-symbol-offset val)))
44 (logior (ash (char-code val) n-widetag-bits)
47 ;; Else, value not immediate.
48 (storew value object offset lowtag))))
52 ;;;; symbol hacking VOPs
54 ;;; these next two cf the sparc version, by jrd.
55 ;;; FIXME: Deref this ^ reference.
58 ;;; The compiler likes to be able to directly SET symbols.
61 (:args (symbol :scs (descriptor-reg))
62 (value :scs (descriptor-reg any-reg)))
63 (:temporary (:sc descriptor-reg) tls)
64 ;;(:policy :fast-safe)
66 (let ((global-val (gen-label))
68 (loadw tls symbol symbol-tls-index-slot other-pointer-lowtag)
70 (inst jmp :z global-val)
71 (inst cmp (make-ea :qword :base thread-base-tn :scale 1 :index tls)
72 no-tls-value-marker-widetag)
73 (inst jmp :z global-val)
74 (inst mov (make-ea :qword :base thread-base-tn :scale 1 :index tls)
77 (emit-label global-val)
78 (storew value symbol symbol-value-slot other-pointer-lowtag)
81 ;; unithreaded it's a lot simpler ...
83 (define-vop (set cell-set)
84 (:variant symbol-value-slot other-pointer-lowtag))
86 ;;; Do a cell ref with an error check for being unbound.
87 ;;; XXX stil used? I can't see where -dan
88 (define-vop (checked-cell-ref)
89 (:args (object :scs (descriptor-reg) :target obj-temp))
90 (:results (value :scs (descriptor-reg any-reg)))
93 (:save-p :compute-only)
94 (:temporary (:sc descriptor-reg :from (:argument 0)) obj-temp))
96 ;;; With Symbol-Value, we check that the value isn't the trap object. So
97 ;;; Symbol-Value of NIL is NIL.
99 (define-vop (symbol-value)
100 (:translate symbol-value)
102 (:args (object :scs (descriptor-reg) :to (:result 1)))
103 (:results (value :scs (descriptor-reg any-reg)))
105 (:save-p :compute-only)
107 (let* ((check-unbound-label (gen-label))
108 (err-lab (generate-error-code vop unbound-symbol-error object))
109 (ret-lab (gen-label)))
110 (loadw value object symbol-tls-index-slot other-pointer-lowtag)
111 (inst mov value (make-ea :qword :base thread-base-tn
112 :index value :scale 1))
113 (inst cmp value no-tls-value-marker-widetag)
114 (inst jmp :ne check-unbound-label)
115 (loadw value object symbol-value-slot other-pointer-lowtag)
116 (emit-label check-unbound-label)
117 (inst cmp value unbound-marker-widetag)
118 (inst jmp :e err-lab)
119 (emit-label ret-lab))))
122 (define-vop (fast-symbol-value symbol-value)
123 ;; KLUDGE: not really fast, in fact, because we're going to have to
124 ;; do a full lookup of the thread-local area anyway. But half of
125 ;; the meaning of FAST-SYMBOL-VALUE is "do not signal an error if
126 ;; unbound", which is used in the implementation of COPY-SYMBOL. --
129 (:translate symbol-value)
131 (let ((ret-lab (gen-label)))
132 (loadw value object symbol-tls-index-slot other-pointer-lowtag)
134 (make-ea :qword :base thread-base-tn :index value :scale 1))
135 (inst cmp value no-tls-value-marker-widetag)
136 (inst jmp :ne ret-lab)
137 (loadw value object symbol-value-slot other-pointer-lowtag)
138 (emit-label ret-lab))))
141 (define-vop (symbol-value)
142 (:translate symbol-value)
144 (:args (object :scs (descriptor-reg) :to (:result 1)))
145 (:results (value :scs (descriptor-reg any-reg)))
147 (:save-p :compute-only)
149 (let ((err-lab (generate-error-code vop unbound-symbol-error object)))
150 (loadw value object symbol-value-slot other-pointer-lowtag)
151 (inst cmp value unbound-marker-widetag)
152 (inst jmp :e err-lab))))
155 (define-vop (fast-symbol-value cell-ref)
156 (:variant symbol-value-slot other-pointer-lowtag)
158 (:translate symbol-value))
160 (defknown locked-symbol-global-value-add (symbol fixnum) fixnum ())
162 (define-vop (locked-symbol-global-value-add)
163 (:args (object :scs (descriptor-reg) :to :result)
164 (value :scs (any-reg) :target result))
165 (:arg-types * tagged-num)
166 (:results (result :scs (any-reg) :from (:argument 1)))
168 (:translate locked-symbol-global-value-add)
169 (:result-types tagged-num)
174 (inst add (make-ea :qword :base object
175 :disp (- (* symbol-value-slot n-word-bytes)
176 other-pointer-lowtag))
183 (:args (object :scs (descriptor-reg)))
186 (:temporary (:sc descriptor-reg #+nil(:from (:argument 0))) value)
188 (let ((check-unbound-label (gen-label)))
189 (loadw value object symbol-tls-index-slot other-pointer-lowtag)
191 (make-ea :qword :base thread-base-tn :index value :scale 1))
192 (inst cmp value no-tls-value-marker-widetag)
193 (inst jmp :ne check-unbound-label)
194 (loadw value object symbol-value-slot other-pointer-lowtag)
195 (emit-label check-unbound-label)
196 (inst cmp value unbound-marker-widetag)
197 (inst jmp (if not-p :e :ne) target))))
203 (:args (object :scs (descriptor-reg)))
206 (:temporary (:sc descriptor-reg :from (:argument 0)) value)
208 (loadw value object symbol-value-slot other-pointer-lowtag)
209 (inst cmp value unbound-marker-widetag)
210 (inst jmp (if not-p :e :ne) target)))
213 (define-vop (symbol-hash)
215 (:translate symbol-hash)
216 (:args (symbol :scs (descriptor-reg)))
217 (:results (res :scs (any-reg)))
218 (:result-types positive-fixnum)
220 ;; The symbol-hash slot of NIL holds NIL because it is also the
221 ;; cdr slot, so we have to strip off the three low bits to make sure
222 ;; it is a fixnum. The lowtag selection magic that is required to
223 ;; ensure this is explained in the comment in objdef.lisp
224 (loadw res symbol symbol-hash-slot other-pointer-lowtag)
225 (inst and res (lognot #b111))))
227 ;;;; fdefinition (FDEFN) objects
229 (define-vop (fdefn-fun cell-ref) ; /pfw - alpha
230 (:variant fdefn-fun-slot other-pointer-lowtag))
232 (define-vop (safe-fdefn-fun)
233 (:args (object :scs (descriptor-reg) :to (:result 1)))
234 (:results (value :scs (descriptor-reg any-reg)))
236 (:save-p :compute-only)
238 (loadw value object fdefn-fun-slot other-pointer-lowtag)
239 (inst cmp value nil-value)
240 (let ((err-lab (generate-error-code vop undefined-fun-error object)))
241 (inst jmp :e err-lab))))
243 (define-vop (set-fdefn-fun)
245 (:translate (setf fdefn-fun))
246 (:args (function :scs (descriptor-reg) :target result)
247 (fdefn :scs (descriptor-reg)))
248 (:temporary (:sc unsigned-reg) raw)
249 (:temporary (:sc byte-reg) type)
250 (:results (result :scs (descriptor-reg)))
252 (load-type type function (- fun-pointer-lowtag))
254 (make-ea :byte :base function
255 :disp (- (* simple-fun-code-offset n-word-bytes)
256 fun-pointer-lowtag)))
257 (inst cmp type simple-fun-header-widetag)
258 (inst jmp :e NORMAL-FUN)
259 (inst lea raw (make-fixup "closure_tramp" :foreign))
261 (storew function fdefn fdefn-fun-slot other-pointer-lowtag)
262 (storew raw fdefn fdefn-raw-addr-slot other-pointer-lowtag)
263 (move result function)))
265 (define-vop (fdefn-makunbound)
267 (:translate fdefn-makunbound)
268 (:args (fdefn :scs (descriptor-reg) :target result))
269 (:results (result :scs (descriptor-reg)))
271 (storew nil-value fdefn fdefn-fun-slot other-pointer-lowtag)
272 (storew (make-fixup "undefined_tramp" :foreign)
273 fdefn fdefn-raw-addr-slot other-pointer-lowtag)
274 (move result fdefn)))
276 ;;;; binding and unbinding
278 ;;; BIND -- Establish VAL as a binding for SYMBOL. Save the old value and
279 ;;; the symbol on the binding stack and stuff the new value into the
284 (:args (val :scs (any-reg descriptor-reg))
285 (symbol :scs (descriptor-reg)))
286 (:temporary (:sc unsigned-reg) tls-index temp bsp)
288 (let ((tls-index-valid (gen-label)))
289 (load-tl-symbol-value bsp *binding-stack-pointer*)
290 (loadw tls-index symbol symbol-tls-index-slot other-pointer-lowtag)
291 (inst add bsp (* binding-size n-word-bytes))
292 (store-tl-symbol-value bsp *binding-stack-pointer* temp)
294 (inst or tls-index tls-index)
295 (inst jmp :ne tls-index-valid)
296 ;; allocate a new tls-index
297 (load-symbol-value tls-index *free-tls-index*)
298 (inst add tls-index 8) ;XXX surely we can do this more
299 (store-symbol-value tls-index *free-tls-index*) ;succintly
300 (inst sub tls-index 8)
301 (storew tls-index symbol symbol-tls-index-slot other-pointer-lowtag)
302 (emit-label tls-index-valid)
304 (make-ea :qword :base thread-base-tn :scale 1 :index tls-index))
305 (storew temp bsp (- binding-value-slot binding-size))
306 (storew symbol bsp (- binding-symbol-slot binding-size))
307 (inst mov (make-ea :qword :base thread-base-tn :scale 1 :index tls-index)
312 (:args (val :scs (any-reg descriptor-reg))
313 (symbol :scs (descriptor-reg)))
314 (:temporary (:sc unsigned-reg) temp bsp)
316 (load-symbol-value bsp *binding-stack-pointer*)
317 (loadw temp symbol symbol-value-slot other-pointer-lowtag)
318 (inst add bsp (* binding-size n-word-bytes))
319 (store-symbol-value bsp *binding-stack-pointer*)
320 (storew temp bsp (- binding-value-slot binding-size))
321 (storew symbol bsp (- binding-symbol-slot binding-size))
322 (storew val symbol symbol-value-slot other-pointer-lowtag)))
328 (:temporary (:sc unsigned-reg) symbol value bsp tls-index)
330 (load-tl-symbol-value bsp *binding-stack-pointer*)
331 (loadw symbol bsp (- binding-symbol-slot binding-size))
332 (loadw value bsp (- binding-value-slot binding-size))
334 (loadw tls-index symbol symbol-tls-index-slot other-pointer-lowtag)
335 (inst mov (make-ea :qword :base thread-base-tn :scale 1 :index tls-index)
338 (storew 0 bsp (- binding-symbol-slot binding-size))
339 (inst sub bsp (* binding-size n-word-bytes))
340 ;; we're done with value, so we can use it as a temp here
341 (store-tl-symbol-value bsp *binding-stack-pointer* value)))
345 (:temporary (:sc unsigned-reg) symbol value bsp)
347 (load-symbol-value bsp *binding-stack-pointer*)
348 (loadw symbol bsp (- binding-symbol-slot binding-size))
349 (loadw value bsp (- binding-value-slot binding-size))
350 (storew value symbol symbol-value-slot other-pointer-lowtag)
351 (storew 0 bsp (- binding-symbol-slot binding-size))
352 (inst sub bsp (* binding-size n-word-bytes))
353 (store-symbol-value bsp *binding-stack-pointer*)))
356 (define-vop (unbind-to-here)
357 (:args (where :scs (descriptor-reg any-reg)))
358 (:temporary (:sc unsigned-reg) symbol value bsp #!+sb-thread tls-index)
360 (load-tl-symbol-value bsp *binding-stack-pointer*)
365 (loadw symbol bsp (- binding-symbol-slot binding-size))
366 (inst or symbol symbol)
368 (loadw value bsp (- binding-value-slot binding-size))
370 (storew value symbol symbol-value-slot other-pointer-lowtag)
372 (loadw tls-index symbol symbol-tls-index-slot other-pointer-lowtag)
374 (inst mov (make-ea :qword :base thread-base-tn :scale 1 :index tls-index)
376 (storew 0 bsp (- binding-symbol-slot binding-size))
379 (inst sub bsp (* binding-size n-word-bytes))
382 ;; we're done with value, so can use it as a temporary
383 (store-tl-symbol-value bsp *binding-stack-pointer* value)
389 ;;;; closure indexing
391 (define-full-reffer closure-index-ref *
392 closure-info-offset fun-pointer-lowtag
393 (any-reg descriptor-reg) * %closure-index-ref)
395 (define-full-setter set-funcallable-instance-info *
396 funcallable-instance-info-offset fun-pointer-lowtag
397 (any-reg descriptor-reg) * %set-funcallable-instance-info)
399 (define-full-reffer funcallable-instance-info *
400 funcallable-instance-info-offset fun-pointer-lowtag
401 (descriptor-reg any-reg) * %funcallable-instance-info)
403 (define-vop (funcallable-instance-lexenv cell-ref)
404 (:variant funcallable-instance-lexenv-slot fun-pointer-lowtag))
406 (define-vop (closure-ref slot-ref)
407 (:variant closure-info-offset fun-pointer-lowtag))
409 (define-vop (closure-init slot-set)
410 (:variant closure-info-offset fun-pointer-lowtag))
412 ;;;; value cell hackery
414 (define-vop (value-cell-ref cell-ref)
415 (:variant value-cell-value-slot other-pointer-lowtag))
417 (define-vop (value-cell-set cell-set)
418 (:variant value-cell-value-slot other-pointer-lowtag))
420 ;;;; structure hackery
422 (define-vop (instance-length)
424 (:translate %instance-length)
425 (:args (struct :scs (descriptor-reg)))
426 (:results (res :scs (unsigned-reg)))
427 (:result-types positive-fixnum)
429 (loadw res struct 0 instance-pointer-lowtag)
430 (inst shr res n-widetag-bits)))
432 (define-vop (instance-ref slot-ref)
433 (:variant instance-slots-offset instance-pointer-lowtag)
435 (:translate %instance-ref)
436 (:arg-types instance (:constant index)))
438 (define-vop (instance-set slot-set)
440 (:translate %instance-set)
441 (:variant instance-slots-offset instance-pointer-lowtag)
442 (:arg-types instance (:constant index) *))
444 (define-full-reffer instance-index-ref * instance-slots-offset
445 instance-pointer-lowtag (any-reg descriptor-reg) * %instance-ref)
447 (define-full-setter instance-index-set * instance-slots-offset
448 instance-pointer-lowtag (any-reg descriptor-reg) * %instance-set)
451 (defknown %instance-set-conditional (instance index t t) t
454 (define-vop (instance-set-conditional)
455 (:translate %instance-set-conditional)
456 (:args (object :scs (descriptor-reg) :to :eval)
457 (slot :scs (any-reg) :to :result)
458 (old-value :scs (descriptor-reg any-reg) :target rax)
459 (new-value :scs (descriptor-reg any-reg)))
460 (:arg-types instance positive-fixnum * *)
461 (:temporary (:sc descriptor-reg :offset rax-offset
462 :from (:argument 2) :to :result :target result) rax)
463 (:results (result :scs (descriptor-reg any-reg)))
464 ;(:guard (backend-featurep :i486))
469 (inst cmpxchg (make-ea :qword :base object :index slot :scale 1
470 :disp (- (* instance-slots-offset n-word-bytes)
471 instance-pointer-lowtag))
477 ;;;; code object frobbing
479 (define-full-reffer code-header-ref * 0 other-pointer-lowtag
480 (any-reg descriptor-reg) * code-header-ref)
482 (define-full-setter code-header-set * 0 other-pointer-lowtag
483 (any-reg descriptor-reg) * code-header-set)
487 ;;;; raw instance slot accessors
489 (define-vop (raw-instance-ref/word)
490 (:translate %raw-instance-ref/word)
492 (:args (object :scs (descriptor-reg)) (index :scs (any-reg)))
493 (:arg-types * tagged-num)
494 (:temporary (:sc unsigned-reg) tmp)
495 (:results (value :scs (unsigned-reg)))
496 (:result-types unsigned-num)
498 (loadw tmp object 0 instance-pointer-lowtag)
499 (inst shr tmp n-widetag-bits)
507 :disp (- (* (1- instance-slots-offset) n-word-bytes)
508 instance-pointer-lowtag)))))
510 (define-vop (raw-instance-set/word)
511 (:translate %raw-instance-set/word)
513 (:args (object :scs (descriptor-reg))
514 (index :scs (any-reg))
515 (value :scs (unsigned-reg) :target result))
516 (:arg-types * tagged-num unsigned-num)
517 (:temporary (:sc unsigned-reg) tmp)
518 (:results (result :scs (unsigned-reg)))
519 (:result-types unsigned-num)
521 (loadw tmp object 0 instance-pointer-lowtag)
522 (inst shr tmp n-widetag-bits)
529 :disp (- (* (1- instance-slots-offset) n-word-bytes)
530 instance-pointer-lowtag))
532 (move result value)))
534 (define-vop (raw-instance-ref/single)
535 (:translate %raw-instance-ref/single)
537 (:args (object :scs (descriptor-reg))
538 (index :scs (any-reg)))
539 (:arg-types * positive-fixnum)
540 (:temporary (:sc unsigned-reg) tmp)
541 (:results (value :scs (single-reg)))
542 (:result-types single-float)
544 (loadw tmp object 0 instance-pointer-lowtag)
545 (inst shr tmp n-widetag-bits)
553 :disp (- (* (1- instance-slots-offset) n-word-bytes)
554 instance-pointer-lowtag)))))
556 (define-vop (raw-instance-set/single)
557 (:translate %raw-instance-set/single)
559 (:args (object :scs (descriptor-reg))
560 (index :scs (any-reg))
561 (value :scs (single-reg) :target result))
562 (:arg-types * positive-fixnum single-float)
563 (:temporary (:sc unsigned-reg) tmp)
564 (:results (result :scs (single-reg)))
565 (:result-types single-float)
567 (loadw tmp object 0 instance-pointer-lowtag)
568 (inst shr tmp n-widetag-bits)
575 :disp (- (* (1- instance-slots-offset) n-word-bytes)
576 instance-pointer-lowtag))
578 (unless (location= result value)
579 (inst movss result value))))
581 (define-vop (raw-instance-ref/double)
582 (:translate %raw-instance-ref/double)
584 (:args (object :scs (descriptor-reg))
585 (index :scs (any-reg)))
586 (:arg-types * positive-fixnum)
587 (:temporary (:sc unsigned-reg) tmp)
588 (:results (value :scs (double-reg)))
589 (:result-types double-float)
591 (loadw tmp object 0 instance-pointer-lowtag)
592 (inst shr tmp n-widetag-bits)
600 :disp (- (* (1- instance-slots-offset) n-word-bytes)
601 instance-pointer-lowtag)))))
603 (define-vop (raw-instance-set/double)
604 (:translate %raw-instance-set/double)
606 (:args (object :scs (descriptor-reg))
607 (index :scs (any-reg))
608 (value :scs (double-reg) :target result))
609 (:arg-types * positive-fixnum double-float)
610 (:temporary (:sc unsigned-reg) tmp)
611 (:results (result :scs (double-reg)))
612 (:result-types double-float)
614 (loadw tmp object 0 instance-pointer-lowtag)
615 (inst shr tmp n-widetag-bits)
622 :disp (- (* (1- instance-slots-offset) n-word-bytes)
623 instance-pointer-lowtag))
625 (unless (location= result value)
626 (inst movsd result value))))
628 (define-vop (raw-instance-ref/complex-single)
629 (:translate %raw-instance-ref/complex-single)
631 (:args (object :scs (descriptor-reg))
632 (index :scs (any-reg)))
633 (:arg-types * positive-fixnum)
634 (:temporary (:sc unsigned-reg) tmp)
635 (:results (value :scs (complex-single-reg)))
636 (:result-types complex-single-float)
638 (loadw tmp object 0 instance-pointer-lowtag)
639 (inst shr tmp n-widetag-bits)
642 (let ((real-tn (complex-single-reg-real-tn value)))
648 :disp (- (* (1- instance-slots-offset) n-word-bytes)
649 instance-pointer-lowtag))))
650 (let ((imag-tn (complex-single-reg-imag-tn value)))
656 :disp (+ (* (1- instance-slots-offset) n-word-bytes)
658 (- instance-pointer-lowtag)))))))
660 (define-vop (raw-instance-set/complex-single)
661 (:translate %raw-instance-set/complex-single)
663 (:args (object :scs (descriptor-reg))
664 (index :scs (any-reg))
665 (value :scs (complex-single-reg) :target result))
666 (:arg-types * positive-fixnum complex-single-float)
667 (:temporary (:sc unsigned-reg) tmp)
668 (:results (result :scs (complex-single-reg)))
669 (:result-types complex-single-float)
671 (loadw tmp object 0 instance-pointer-lowtag)
672 (inst shr tmp n-widetag-bits)
675 (let ((value-real (complex-single-reg-real-tn value))
676 (result-real (complex-single-reg-real-tn result)))
677 (inst movss (make-ea :dword
680 :disp (- (* (1- instance-slots-offset) n-word-bytes)
681 instance-pointer-lowtag))
683 (unless (location= value-real result-real)
684 (inst movss result-real value-real)))
685 (let ((value-imag (complex-single-reg-imag-tn value))
686 (result-imag (complex-single-reg-imag-tn result)))
687 (inst movss (make-ea :dword
690 :disp (+ (* (1- instance-slots-offset) n-word-bytes)
692 (- instance-pointer-lowtag)))
694 (unless (location= value-imag result-imag)
695 (inst movss result-imag value-imag)))))
697 (define-vop (raw-instance-ref/complex-double)
698 (:translate %raw-instance-ref/complex-double)
700 (:args (object :scs (descriptor-reg))
701 (index :scs (any-reg)))
702 (:arg-types * positive-fixnum)
703 (:temporary (:sc unsigned-reg) tmp)
704 (:results (value :scs (complex-double-reg)))
705 (:result-types complex-double-float)
707 (loadw tmp object 0 instance-pointer-lowtag)
708 (inst shr tmp n-widetag-bits)
711 (let ((real-tn (complex-double-reg-real-tn value)))
717 :disp (- (* (- instance-slots-offset 2) n-word-bytes)
718 instance-pointer-lowtag))))
719 (let ((imag-tn (complex-double-reg-imag-tn value)))
725 :disp (- (* (1- instance-slots-offset) n-word-bytes)
726 instance-pointer-lowtag))))))
728 (define-vop (raw-instance-set/complex-double)
729 (:translate %raw-instance-set/complex-double)
731 (:args (object :scs (descriptor-reg))
732 (index :scs (any-reg))
733 (value :scs (complex-double-reg) :target result))
734 (:arg-types * positive-fixnum complex-double-float)
735 (:temporary (:sc unsigned-reg) tmp)
736 (:results (result :scs (complex-double-reg)))
737 (:result-types complex-double-float)
739 (loadw tmp object 0 instance-pointer-lowtag)
740 (inst shr tmp n-widetag-bits)
743 (let ((value-real (complex-double-reg-real-tn value))
744 (result-real (complex-double-reg-real-tn result)))
745 (inst movsd (make-ea :dword
748 :disp (- (* (- instance-slots-offset 2) n-word-bytes)
749 instance-pointer-lowtag))
751 (unless (location= value-real result-real)
752 (inst movsd result-real value-real)))
753 (let ((value-imag (complex-double-reg-imag-tn value))
754 (result-imag (complex-double-reg-imag-tn result)))
755 (inst movsd (make-ea :dword
758 :disp (- (* (1- instance-slots-offset) n-word-bytes)
759 instance-pointer-lowtag))
761 (unless (location= value-imag result-imag)
762 (inst movsd result-imag value-imag)))))