src/compiler/x86-64/nlx.lisp

   1 ;;;; the definition of non-local exit for the x86 VM
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   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.
  11
  12 (in-package "SB!VM")
  13
  14 ;;; Make a TN for the argument count passing location for a non-local entry.
  15 (defun make-nlx-entry-arg-start-location ()
  16     (make-wired-tn *fixnum-primitive-type* any-reg-sc-number rbx-offset))
  17
  18 (defun catch-block-ea (tn)
  19   (aver (sc-is tn catch-block))
  20   (make-ea :qword :base rbp-tn
  21            :disp (frame-byte-offset (+ -1 (tn-offset tn) catch-block-size))))
  22
  23 (defun unwind-block-ea (tn)
  24   (aver (sc-is tn unwind-block))
  25   (make-ea :qword :base rbp-tn
  26                   :disp (frame-byte-offset (+ -1 (tn-offset tn) unwind-block-size))))
  27 \f
  28 ;;;; Save and restore dynamic environment.
  29 ;;;;
  30 ;;;; These VOPs are used in the reentered function to restore the
  31 ;;;; appropriate dynamic environment. Currently we only save the
  32 ;;;; Current-Catch. (Before sbcl-0.7.0,
  33 ;;;; when there were IR1 and byte interpreters, we had to save
  34 ;;;; the interpreter "eval stack" too.)
  35 ;;;;
  36 ;;;; We don't need to save/restore the current UNWIND-PROTECT, since
  37 ;;;; UNWIND-PROTECTs are implicitly processed during unwinding.
  38 ;;;;
  39 ;;;; We don't need to save the BSP, because that is handled automatically.
  40
  41 (define-vop (save-dynamic-state)
  42   (:results (catch :scs (descriptor-reg)))
  43   (:generator 13
  44     (load-tl-symbol-value catch *current-catch-block*)))
  45
  46 (define-vop (restore-dynamic-state)
  47   (:args (catch :scs (descriptor-reg)))
  48   (:generator 10
  49     (store-tl-symbol-value catch *current-catch-block*)))
  50
  51 (define-vop (current-stack-pointer)
  52   (:results (res :scs (any-reg control-stack)))
  53   (:generator 1
  54     (move res rsp-tn)))
  55
  56 (define-vop (current-binding-pointer)
  57   (:results (res :scs (any-reg descriptor-reg)))
  58   (:generator 1
  59     (load-binding-stack-pointer res)))
  60 \f
  61 ;;;; unwind block hackery
  62
  63 ;;; Compute the address of the catch block from its TN, then store into the
  64 ;;; block the current Fp, Env, Unwind-Protect, and the entry PC.
  65 (define-vop (make-unwind-block)
  66   (:args (tn))
  67   (:info entry-label)
  68   (:temporary (:sc unsigned-reg) temp)
  69   (:results (block :scs (any-reg)))
  70   (:generator 22
  71     (inst lea block (unwind-block-ea tn))
  72     (load-tl-symbol-value temp *current-unwind-protect-block*)
  73     (storew temp block unwind-block-uwp-slot)
  74     (storew rbp-tn block unwind-block-cfp-slot)
  75     (inst lea temp (make-fixup nil :code-object entry-label))
  76     (storew temp block unwind-block-entry-pc-slot)))
  77
  78 ;;; like MAKE-UNWIND-BLOCK, except that we also store in the specified
  79 ;;; tag, and link the block into the CURRENT-CATCH list
  80 (define-vop (make-catch-block)
  81   (:args (tn)
  82          (tag :scs (any-reg descriptor-reg) :to (:result 1)))
  83   (:info entry-label)
  84   (:results (block :scs (any-reg)))
  85   (:temporary (:sc descriptor-reg) temp)
  86   (:generator 44
  87     (inst lea block (catch-block-ea tn))
  88     (load-tl-symbol-value temp *current-unwind-protect-block*)
  89     (storew temp block catch-block-uwp-slot)
  90     (storew rbp-tn block catch-block-cfp-slot)
  91     (inst lea temp (make-fixup nil :code-object entry-label))
  92     (storew temp block catch-block-entry-pc-slot)
  93     (storew tag block catch-block-tag-slot)
  94     (load-tl-symbol-value temp *current-catch-block*)
  95     (storew temp block catch-block-previous-catch-slot)
  96     (store-tl-symbol-value block *current-catch-block*)))
  97
  98 ;;; Just set the current unwind-protect to TN's address. This instantiates an
  99 ;;; unwind block as an unwind-protect.
 100 (define-vop (set-unwind-protect)
 101   (:args (tn))
 102   (:temporary (:sc unsigned-reg) new-uwp)
 103   (:generator 7
 104     (inst lea new-uwp (unwind-block-ea tn))
 105     (store-tl-symbol-value new-uwp *current-unwind-protect-block*)))
 106
 107 (define-vop (unlink-catch-block)
 108   (:temporary (:sc unsigned-reg) block)
 109   (:policy :fast-safe)
 110   (:translate %catch-breakup)
 111   (:generator 17
 112     (load-tl-symbol-value block *current-catch-block*)
 113     (loadw block block catch-block-previous-catch-slot)
 114     (store-tl-symbol-value block *current-catch-block*)))
 115
 116 (define-vop (unlink-unwind-protect)
 117     (:temporary (:sc unsigned-reg) block)
 118   (:policy :fast-safe)
 119   (:translate %unwind-protect-breakup)
 120   (:generator 17
 121     (load-tl-symbol-value block *current-unwind-protect-block*)
 122     (loadw block block unwind-block-uwp-slot)
 123     (store-tl-symbol-value block *current-unwind-protect-block*)))
 124 \f
 125 ;;;; NLX entry VOPs
 126 (define-vop (nlx-entry)
 127   ;; Note: we can't list an sc-restriction, 'cause any load vops would
 128   ;; be inserted before the return-pc label.
 129   (:args (sp)
 130          (start)
 131          (count))
 132   (:results (values :more t))
 133   (:temporary (:sc descriptor-reg) move-temp)
 134   (:info label nvals)
 135   (:save-p :force-to-stack)
 136   (:vop-var vop)
 137   (:generator 30
 138     (emit-label label)
 139     (note-this-location vop :non-local-entry)
 140     (cond ((zerop nvals))
 141           ((= nvals 1)
 142            (let ((no-values (gen-label)))
 143              (inst mov (tn-ref-tn values) nil-value)
 144              (inst jrcxz no-values)
 145              (loadw (tn-ref-tn values) start -1)
 146              (emit-label no-values)))
 147           (t
 148            ;; FIXME: this is mostly copied from
 149            ;; DEFAULT-UNKNOWN-VALUES.
 150            (collect ((defaults))
 151              (do ((i 0 (1+ i))
 152                   (tn-ref values (tn-ref-across tn-ref)))
 153                  ((null tn-ref))
 154                (let ((default-lab (gen-label))
 155                      (tn (tn-ref-tn tn-ref))
 156                      (first-stack-arg-p (= i register-arg-count)))
 157                  (defaults (cons default-lab (cons tn first-stack-arg-p)))
 158                  (inst cmp count (fixnumize i))
 159                  (inst jmp :le default-lab)
 160                  (when first-stack-arg-p
 161                    (storew rdx-tn rbx-tn -1))
 162                  (sc-case tn
 163                    ((descriptor-reg any-reg)
 164                     (loadw tn start (frame-word-offset (+ sp->fp-offset i))))
 165                    ((control-stack)
 166                     (loadw move-temp start
 167                            (frame-word-offset (+ sp->fp-offset i)))
 168                     (inst mov tn move-temp)))))
 169              (let ((defaulting-done (gen-label)))
 170                (emit-label defaulting-done)
 171                (assemble (*elsewhere*)
 172                  (dolist (default (defaults))
 173                    (emit-label (car default))
 174                    (when (cddr default)
 175                      (inst push rdx-tn))
 176                    (inst mov (second default) nil-value))
 177                  (inst jmp defaulting-done))))))
 178     (inst mov rsp-tn sp)))
 179
 180 (define-vop (nlx-entry-multiple)
 181   (:args (top)
 182          (source)
 183          (count :target rcx))
 184   ;; Again, no SC restrictions for the args, 'cause the loading would
 185   ;; happen before the entry label.
 186   (:info label)
 187   (:temporary (:sc unsigned-reg :offset rcx-offset :from (:argument 2)) rcx)
 188   (:temporary (:sc unsigned-reg :offset rsi-offset) rsi)
 189   (:temporary (:sc unsigned-reg :offset rdi-offset) rdi)
 190   (:results (result :scs (any-reg) :from (:argument 0))
 191             (num :scs (any-reg control-stack)))
 192   (:save-p :force-to-stack)
 193   (:vop-var vop)
 194   (:generator 30
 195     (emit-label label)
 196     (note-this-location vop :non-local-entry)
 197
 198     (inst lea rsi (make-ea :qword :base source :disp (- n-word-bytes)))
 199     ;; The 'top' arg contains the %esp value saved at the time the
 200     ;; catch block was created and points to where the thrown values
 201     ;; should sit.
 202     (move rdi top)
 203     (move result rdi)
 204
 205     (inst sub rdi n-word-bytes)
 206     (move rcx count)                    ; fixnum words == bytes
 207     (move num rcx)
 208     (inst shr rcx n-fixnum-tag-bits)    ; word count for <rep movs>
 209     ;; If we got zero, we be done.
 210     (inst jrcxz DONE)
 211     ;; Copy them down.
 212     (inst std)
 213     (inst rep)
 214     (inst movs :qword)
 215     (inst cld)
 216     DONE
 217     ;; Reset the CSP at last moved arg.
 218     (inst lea rsp-tn (make-ea :qword :base rdi :disp n-word-bytes))))
 219
 220
 221 ;;; This VOP is just to force the TNs used in the cleanup onto the stack.
 222 (define-vop (uwp-entry)
 223   (:info label)
 224   (:save-p :force-to-stack)
 225   (:results (block) (start) (count))
 226   (:ignore block start count)
 227   (:vop-var vop)
 228   (:generator 0
 229     (emit-label label)
 230     (note-this-location vop :non-local-entry)))
 231
 232 (define-vop (unwind-to-frame-and-call)
 233     (:args (ofp :scs (descriptor-reg))
 234            (uwp :scs (descriptor-reg))
 235            (function :scs (descriptor-reg) :to :load :target saved-function))
 236   (:arg-types system-area-pointer system-area-pointer t)
 237   (:temporary (:sc sap-reg) temp)
 238   (:temporary (:sc descriptor-reg :offset rbx-offset) saved-function)
 239   (:temporary (:sc unsigned-reg :offset rax-offset) block)
 240   (:generator 22
 241     ;; Store the function into a non-stack location, since we'll be
 242     ;; unwinding the stack and destroying register contents before we
 243     ;; use it.  It turns out that RBX is preserved as part of the
 244     ;; normal multiple-value handling of an unwind, so use that.
 245     (move saved-function function)
 246
 247     ;; Allocate space for magic UWP block.
 248     (inst sub rsp-tn (* unwind-block-size n-word-bytes))
 249     ;; Set up magic catch / UWP block.
 250     (move block rsp-tn)
 251     (loadw temp uwp sap-pointer-slot other-pointer-lowtag)
 252     (storew temp block unwind-block-uwp-slot)
 253     (loadw temp ofp sap-pointer-slot other-pointer-lowtag)
 254     (storew temp block unwind-block-cfp-slot)
 255
 256     (inst lea temp-reg-tn (make-fixup nil :code-object entry-label))
 257     (storew temp-reg-tn block unwind-block-entry-pc-slot)
 258
 259     ;; Run any required UWPs.
 260     (inst mov temp-reg-tn (make-fixup 'unwind :assembly-routine))
 261     (inst jmp temp-reg-tn)
 262     ENTRY-LABEL
 263
 264     ;; Move our saved function to where we want it now.
 265     (move block saved-function)
 266
 267     ;; No parameters
 268     (zeroize rcx-tn)
 269
 270     ;; Clear the stack
 271     (inst lea rsp-tn
 272           (make-ea :qword :base rbp-tn
 273                    :disp (* (- sp->fp-offset 3) n-word-bytes)))
 274
 275     ;; Push the return-pc so it looks like we just called.
 276     (pushw rbp-tn (frame-word-offset return-pc-save-offset))
 277
 278     ;; Call it
 279     (inst jmp (make-ea :qword :base block
 280                        :disp (- (* closure-fun-slot n-word-bytes)
 281                                 fun-pointer-lowtag)))))