;;;; the definitions of VOPs used for non-local exit (THROW, lexical;;;; exit, etc.);;;; This software is part of the SBCL system. See the README file for;;;; more information.;;;;;;;; This software is derived from the CMU CL system, which was;;;; written at Carnegie Mellon University and released into the;;;; public domain. The software is in the public domain and is;;;; provided with absolutely no warranty. See the COPYING and CREDITS;;;; files for more information.(in-package "SB!VM");;; Make an environment-live stack TN for saving the SP for NLX entry.(!def-vm-support-routine make-nlx-sp-tn (env)  (physenv-live-tn   (make-representation-tn *fixnum-primitive-type* immediate-arg-scn)   env));;; Make a TN for the argument count passing location for a;;; non-local entry.(!def-vm-support-routine make-nlx-entry-arg-start-location ()  (make-wired-tn *fixnum-primitive-type* immediate-arg-scn ocfp-offset));;;; save and restoring the dynamic environment;;;;;;;; These VOPs are used in the reentered function to restore the;;;; appropriate dynamic environment. Currently we only save the;;;; CURRENT-CATCH and binding stack pointer. We don't need to;;;; save/restore the current UNWIND-PROTECT, since UNWIND-PROTECTS;;;; are implicitly processed during unwinding. If there were any;;;; additional stacks (as e.g. there was an interpreter "eval stack";;;; before sbcl-0.7.0), then this would be the place to restore the;;;; top pointers.(define-vop (save-dynamic-state)  (:results (catch :scs (descriptor-reg))            (nfp :scs (descriptor-reg))            (nsp :scs (descriptor-reg)))  (:vop-var vop)  (:generator 13    (load-symbol-value catch *current-catch-block*)    (let ((cur-nfp (current-nfp-tn vop)))      (when cur-nfp        (inst mskll cur-nfp 4 nfp)))    (inst mskll nsp-tn 4 nsp)))(define-vop (restore-dynamic-state)  (:args (catch :scs (descriptor-reg))         (nfp :scs (descriptor-reg))         (nsp :scs (descriptor-reg)))  (:vop-var vop)  (:temporary (:sc any-reg) temp)  (:generator 10    (store-symbol-value catch *current-catch-block*)    (inst mskll nsp-tn 0 temp)    (let ((cur-nfp (current-nfp-tn vop)))      (when cur-nfp        (inst bis nfp temp cur-nfp)))    (inst bis nsp temp nsp-tn)))(define-vop (current-stack-pointer)  (:results (res :scs (any-reg descriptor-reg)))  (:generator 1    (move csp-tn res)))(define-vop (current-binding-pointer)  (:results (res :scs (any-reg descriptor-reg)))  (:generator 1    (move bsp-tn res)));;;; unwind block hackery;;; Compute the address of the catch block from its TN, then store;;; into the block the current Fp, Env, Unwind-Protect, and the entry PC.(define-vop (make-unwind-block)  (:args (tn))  (:info entry-label)  (:results (block :scs (any-reg)))  (:temporary (:scs (descriptor-reg)) temp)  (:temporary (:scs (non-descriptor-reg)) ndescr)  (:generator 22    (inst lda block (* (tn-offset tn) n-word-bytes) cfp-tn)    (load-symbol-value temp *current-unwind-protect-block*)    (storew temp block unwind-block-current-uwp-slot)    (storew cfp-tn block unwind-block-current-cont-slot)    (storew code-tn block unwind-block-current-code-slot)    (inst compute-lra-from-code temp code-tn entry-label ndescr)    (storew temp block catch-block-entry-pc-slot)));;; This is like Make-Unwind-Block, except that we also store in the;;; specified tag, and link the block into the Current-Catch list.(define-vop (make-catch-block)  (:args (tn)         (tag :scs (any-reg descriptor-reg)))  (:info entry-label)  (:results (block :scs (any-reg)))  (:temporary (:scs (descriptor-reg)) temp)  (:temporary (:scs (descriptor-reg) :target block :to (:result 0)) result)  (:temporary (:scs (non-descriptor-reg)) ndescr)  (:generator 44    (inst lda result (* (tn-offset tn) n-word-bytes) cfp-tn)    (load-symbol-value temp *current-unwind-protect-block*)    (storew temp result catch-block-current-uwp-slot)    (storew cfp-tn result catch-block-current-cont-slot)    (storew code-tn result catch-block-current-code-slot)    (inst compute-lra-from-code temp code-tn entry-label ndescr)    (storew temp result catch-block-entry-pc-slot)    (storew tag result catch-block-tag-slot)    (load-symbol-value temp *current-catch-block*)    (storew temp result catch-block-previous-catch-slot)    (store-symbol-value result *current-catch-block*)    (move result block)));;; Just set the current unwind-protect to TN's address. This;;; instantiates an unwind block as an unwind-protect.(define-vop (set-unwind-protect)  (:args (tn))  (:temporary (:scs (descriptor-reg)) new-uwp)  (:generator 7    (inst lda new-uwp (* (tn-offset tn) n-word-bytes) cfp-tn)    (store-symbol-value new-uwp *current-unwind-protect-block*)))(define-vop (unlink-catch-block)  (:temporary (:scs (any-reg)) block)  (:policy :fast-safe)  (:translate %catch-breakup)  (:generator 17    (load-symbol-value block *current-catch-block*)    (loadw block block catch-block-previous-catch-slot)    (store-symbol-value block *current-catch-block*)))(define-vop (unlink-unwind-protect)  (:temporary (:scs (any-reg)) block)  (:policy :fast-safe)  (:translate %unwind-protect-breakup)  (:generator 17    (load-symbol-value block *current-unwind-protect-block*)    (loadw block block unwind-block-current-uwp-slot)    (store-symbol-value block *current-unwind-protect-block*)));;;; NLX entry VOPs(define-vop (nlx-entry)  (:args (sp) ; Note: we can't list an sc-restriction, 'cause any load vops              ; would be inserted before the LRA.         (start)         (count))  (:results (values :more t))  (:temporary (:scs (descriptor-reg)) move-temp)  (:temporary (:sc non-descriptor-reg) temp)  (:info label nvals)  (:save-p :force-to-stack)  (:vop-var vop)  (:generator 30    (emit-return-pc label)    (note-this-location vop :non-local-entry)    (cond ((zerop nvals))          ((= nvals 1)           (let ((no-values (gen-label)))             (move null-tn (tn-ref-tn values))             (inst beq count no-values)             (loadw (tn-ref-tn values) start)             (emit-label no-values)))          (t           (collect ((defaults))             (do ((i 0 (1+ i))                  (tn-ref values (tn-ref-across tn-ref)))                 ((null tn-ref))               (let ((default-lab (gen-label))                     (tn (tn-ref-tn tn-ref)))                 (defaults (cons default-lab tn))                 (inst move count temp)                 (inst lda count (fixnumize -1) count)                 (inst beq temp default-lab)                 (sc-case tn                          ((descriptor-reg any-reg)                           (loadw tn start i))                          (control-stack                           (loadw move-temp start i)                           (store-stack-tn tn move-temp)))))             (let ((defaulting-done (gen-label)))               (emit-label defaulting-done)               (assemble (*elsewhere*)                 (dolist (def (defaults))                   (emit-label (car def))                   (let ((tn (cdr def)))                     (sc-case tn                              ((descriptor-reg any-reg)                               (move null-tn tn))                              (control-stack                               (store-stack-tn tn null-tn)))))                 (inst br zero-tn defaulting-done))))))    (load-stack-tn csp-tn sp)))(define-vop (nlx-entry-multiple)  (:args (top :target dst) (start :target src) (count :target num))  ;; Again, no SC restrictions for the args, 'cause the loading would  ;; happen before the entry label.  (:info label)  (:temporary (:scs (any-reg) :from (:argument 0)) dst)  (:temporary (:scs (any-reg) :from (:argument 1)) src)  (:temporary (:scs (any-reg) :from (:argument 2)) num)  (:temporary (:scs (descriptor-reg)) temp)  (:results (new-start) (new-count))  (:save-p :force-to-stack)  (:vop-var vop)  (:generator 30    (emit-return-pc label)    (note-this-location vop :non-local-entry)    (let ((loop (gen-label))          (done (gen-label)))      ;; Copy args.      (load-stack-tn dst top)      (move start src)      (move count num)      ;; Establish results.      (sc-case new-start        (any-reg (move dst new-start))        (control-stack (store-stack-tn new-start dst)))      (sc-case new-count        (any-reg (inst move num new-count))        (control-stack (store-stack-tn new-count num)))      (inst beq num done)      ;; Copy stuff on stack.      (emit-label loop)      (loadw temp src)      (inst lda src n-word-bytes src)      (storew temp dst)      (inst lda num (fixnumize -1) num)      (inst lda dst n-word-bytes dst)      (inst bne num loop)      (emit-label done)      (inst move dst csp-tn))));;; This VOP is just to force the TNs used in the cleanup onto the stack.(define-vop (uwp-entry)  (:info label)  (:save-p :force-to-stack)  (:results (block) (start) (count))  (:ignore block start count)  (:vop-var vop)  (:generator 0    (emit-return-pc label)    (note-this-location vop :non-local-entry)))