src/compiler/alpha/nlx.lisp

   1 ;;;; the definitions of VOPs used for non-local exit (THROW, lexical
   2 ;;;; exit, etc.)
   3
   4 ;;;; This software is part of the SBCL system. See the README file for
   5 ;;;; more information.
   6 ;;;;
   7 ;;;; This software is derived from the CMU CL system, which was
   8 ;;;; written at Carnegie Mellon University and released into the
   9 ;;;; public domain. The software is in the public domain and is
  10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  11 ;;;; files for more information.
  12
  13 (in-package "SB!VM")
  14
  15 ;;; Make an environment-live stack TN for saving the SP for NLX entry.
  16 (defun make-nlx-sp-tn (env)
  17   (physenv-live-tn
  18    (make-representation-tn *fixnum-primitive-type* immediate-arg-scn)
  19    env))
  20
  21 ;;; Make a TN for the argument count passing location for a
  22 ;;; non-local entry.
  23 (defun make-nlx-entry-arg-start-location ()
  24   (make-wired-tn *fixnum-primitive-type* immediate-arg-scn ocfp-offset))
  25 \f
  26 ;;;; save and restoring the dynamic environment
  27 ;;;;
  28 ;;;; These VOPs are used in the reentered function to restore the
  29 ;;;; appropriate dynamic environment. Currently we only save the
  30 ;;;; CURRENT-CATCH and binding stack pointer. We don't need to
  31 ;;;; save/restore the current UNWIND-PROTECT, since UNWIND-PROTECTS
  32 ;;;; are implicitly processed during unwinding. If there were any
  33 ;;;; additional stacks (as e.g. there was an interpreter "eval stack"
  34 ;;;; before sbcl-0.7.0), then this would be the place to restore the
  35 ;;;; top pointers.
  36
  37 (define-vop (save-dynamic-state)
  38   (:results (catch :scs (descriptor-reg))
  39             (nfp :scs (descriptor-reg))
  40             (nsp :scs (descriptor-reg)))
  41   (:vop-var vop)
  42   (:generator 13
  43     (load-symbol-value catch *current-catch-block*)
  44     (let ((cur-nfp (current-nfp-tn vop)))
  45       (when cur-nfp
  46         (inst mskll cur-nfp 4 nfp)))
  47     (inst mskll nsp-tn 4 nsp)))
  48
  49 (define-vop (restore-dynamic-state)
  50   (:args (catch :scs (descriptor-reg))
  51          (nfp :scs (descriptor-reg))
  52          (nsp :scs (descriptor-reg)))
  53   (:vop-var vop)
  54   (:temporary (:sc any-reg) temp)
  55   (:generator 10
  56     (store-symbol-value catch *current-catch-block*)
  57     (inst mskll nsp-tn 0 temp)
  58     (let ((cur-nfp (current-nfp-tn vop)))
  59       (when cur-nfp
  60         (inst bis nfp temp cur-nfp)))
  61     (inst bis nsp temp nsp-tn)))
  62
  63 (define-vop (current-stack-pointer)
  64   (:results (res :scs (any-reg descriptor-reg)))
  65   (:generator 1
  66     (move csp-tn res)))
  67
  68 (define-vop (current-binding-pointer)
  69   (:results (res :scs (any-reg descriptor-reg)))
  70   (:generator 1
  71     (move bsp-tn res)))
  72 \f
  73 ;;;; unwind block hackery
  74
  75 ;;; Compute the address of the catch block from its TN, then store
  76 ;;; into the block the current Fp, Env, Unwind-Protect, and the entry PC.
  77 (define-vop (make-unwind-block)
  78   (:args (tn))
  79   (:info entry-label)
  80   (:results (block :scs (any-reg)))
  81   (:temporary (:scs (descriptor-reg)) temp)
  82   (:temporary (:scs (non-descriptor-reg)) ndescr)
  83   (:generator 22
  84     (inst lda block (* (tn-offset tn) n-word-bytes) cfp-tn)
  85     (load-symbol-value temp *current-unwind-protect-block*)
  86     (storew temp block unwind-block-current-uwp-slot)
  87     (storew cfp-tn block unwind-block-current-cont-slot)
  88     (storew code-tn block unwind-block-current-code-slot)
  89     (inst compute-lra-from-code temp code-tn entry-label ndescr)
  90     (storew temp block catch-block-entry-pc-slot)))
  91
  92
  93 ;;; This is like Make-Unwind-Block, except that we also store in the
  94 ;;; specified tag, and link the block into the Current-Catch list.
  95 (define-vop (make-catch-block)
  96   (:args (tn)
  97          (tag :scs (any-reg descriptor-reg)))
  98   (:info entry-label)
  99   (:results (block :scs (any-reg)))
 100   (:temporary (:scs (descriptor-reg)) temp)
 101   (:temporary (:scs (descriptor-reg) :target block :to (:result 0)) result)
 102   (:temporary (:scs (non-descriptor-reg)) ndescr)
 103   (:generator 44
 104     (inst lda result (* (tn-offset tn) n-word-bytes) cfp-tn)
 105     (load-symbol-value temp *current-unwind-protect-block*)
 106     (storew temp result catch-block-current-uwp-slot)
 107     (storew cfp-tn result catch-block-current-cont-slot)
 108     (storew code-tn result catch-block-current-code-slot)
 109     (inst compute-lra-from-code temp code-tn entry-label ndescr)
 110     (storew temp result catch-block-entry-pc-slot)
 111
 112     (storew tag result catch-block-tag-slot)
 113     (load-symbol-value temp *current-catch-block*)
 114     (storew temp result catch-block-previous-catch-slot)
 115     (store-symbol-value result *current-catch-block*)
 116
 117     (move result block)))
 118
 119 ;;; Just set the current unwind-protect to TN's address. This
 120 ;;; instantiates an unwind block as an unwind-protect.
 121 (define-vop (set-unwind-protect)
 122   (:args (tn))
 123   (:temporary (:scs (descriptor-reg)) new-uwp)
 124   (:generator 7
 125     (inst lda new-uwp (* (tn-offset tn) n-word-bytes) cfp-tn)
 126     (store-symbol-value new-uwp *current-unwind-protect-block*)))
 127
 128 (define-vop (unlink-catch-block)
 129   (:temporary (:scs (any-reg)) block)
 130   (:policy :fast-safe)
 131   (:translate %catch-breakup)
 132   (:generator 17
 133     (load-symbol-value block *current-catch-block*)
 134     (loadw block block catch-block-previous-catch-slot)
 135     (store-symbol-value block *current-catch-block*)))
 136
 137 (define-vop (unlink-unwind-protect)
 138   (:temporary (:scs (any-reg)) block)
 139   (:policy :fast-safe)
 140   (:translate %unwind-protect-breakup)
 141   (:generator 17
 142     (load-symbol-value block *current-unwind-protect-block*)
 143     (loadw block block unwind-block-current-uwp-slot)
 144     (store-symbol-value block *current-unwind-protect-block*)))
 145 \f
 146 ;;;; NLX entry VOPs
 147
 148 (define-vop (nlx-entry)
 149   (:args (sp) ; Note: we can't list an sc-restriction, 'cause any load vops
 150               ; would be inserted before the LRA.
 151          (start)
 152          (count))
 153   (:results (values :more t))
 154   (:temporary (:scs (descriptor-reg)) move-temp)
 155   (:temporary (:sc non-descriptor-reg) temp)
 156   (:info label nvals)
 157   (:save-p :force-to-stack)
 158   (:vop-var vop)
 159   (:generator 30
 160     (emit-return-pc label)
 161     (note-this-location vop :non-local-entry)
 162     (cond ((zerop nvals))
 163           ((= nvals 1)
 164            (let ((no-values (gen-label)))
 165              (move null-tn (tn-ref-tn values))
 166              (inst beq count no-values)
 167              (loadw (tn-ref-tn values) start)
 168              (emit-label no-values)))
 169           (t
 170            (collect ((defaults))
 171              (do ((i 0 (1+ i))
 172                   (tn-ref values (tn-ref-across tn-ref)))
 173                  ((null tn-ref))
 174                (let ((default-lab (gen-label))
 175                      (tn (tn-ref-tn tn-ref)))
 176                  (defaults (cons default-lab tn))
 177
 178                  (inst move count temp)
 179                  (inst lda count (fixnumize -1) count)
 180                  (inst beq temp default-lab)
 181                  (sc-case tn
 182                           ((descriptor-reg any-reg)
 183                            (loadw tn start i))
 184                           (control-stack
 185                            (loadw move-temp start i)
 186                            (store-stack-tn tn move-temp)))))
 187
 188              (let ((defaulting-done (gen-label)))
 189
 190                (emit-label defaulting-done)
 191
 192                (assemble (*elsewhere*)
 193                  (dolist (def (defaults))
 194                    (emit-label (car def))
 195                    (let ((tn (cdr def)))
 196                      (sc-case tn
 197                               ((descriptor-reg any-reg)
 198                                (move null-tn tn))
 199                               (control-stack
 200                                (store-stack-tn tn null-tn)))))
 201                  (inst br zero-tn defaulting-done))))))
 202     (load-stack-tn csp-tn sp)))
 203
 204 (define-vop (nlx-entry-multiple)
 205   (:args (top :target dst) (start :target src) (count :target num))
 206   ;; Again, no SC restrictions for the args, 'cause the loading would
 207   ;; happen before the entry label.
 208   (:info label)
 209   (:temporary (:scs (any-reg) :from (:argument 0)) dst)
 210   (:temporary (:scs (any-reg) :from (:argument 1)) src)
 211   (:temporary (:scs (any-reg) :from (:argument 2)) num)
 212   (:temporary (:scs (descriptor-reg)) temp)
 213   (:results (new-start) (new-count))
 214   (:save-p :force-to-stack)
 215   (:vop-var vop)
 216   (:generator 30
 217     (emit-return-pc label)
 218     (note-this-location vop :non-local-entry)
 219     (let ((loop (gen-label))
 220           (done (gen-label)))
 221
 222       ;; Copy args.
 223       (load-stack-tn dst top)
 224       (move start src)
 225       (move count num)
 226
 227       ;; Establish results.
 228       (sc-case new-start
 229         (any-reg (move dst new-start))
 230         (control-stack (store-stack-tn new-start dst)))
 231       (sc-case new-count
 232         (any-reg (inst move num new-count))
 233         (control-stack (store-stack-tn new-count num)))
 234       (inst beq num done)
 235
 236       ;; Copy stuff on stack.
 237       (emit-label loop)
 238       (loadw temp src)
 239       (inst lda src n-word-bytes src)
 240       (storew temp dst)
 241       (inst lda num (fixnumize -1) num)
 242       (inst lda dst n-word-bytes dst)
 243       (inst bne num loop)
 244
 245       (emit-label done)
 246       (inst move dst csp-tn))))
 247
 248 ;;; This VOP is just to force the TNs used in the cleanup onto the stack.
 249 (define-vop (uwp-entry)
 250   (:info label)
 251   (:save-p :force-to-stack)
 252   (:results (block) (start) (count))
 253   (:ignore block start count)
 254   (:vop-var vop)
 255   (:generator 0
 256     (emit-return-pc label)
 257     (note-this-location vop :non-local-entry)))