src/compiler/x86-64/values.lisp

   1 ;;;; unknown-values VOPs 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 (define-vop (reset-stack-pointer)
  15   (:args (ptr :scs (any-reg)))
  16   (:generator 1
  17     (move rsp-tn ptr)))
  18
  19 (define-vop (%%nip-values)
  20   (:args (last-nipped-ptr :scs (any-reg) :target rdi)
  21          (last-preserved-ptr :scs (any-reg) :target rsi)
  22          (moved-ptrs :scs (any-reg) :more t))
  23   (:results (r-moved-ptrs :scs (any-reg) :more t)
  24             ;; same as MOVED-PTRS
  25             )
  26   (:temporary (:sc any-reg :offset rsi-offset) rsi)
  27   (:temporary (:sc any-reg :offset rdi-offset) rdi)
  28   (:ignore r-moved-ptrs)
  29   (:generator 1
  30     (move rdi last-nipped-ptr)
  31     (move rsi last-preserved-ptr)
  32     (inst sub rsi n-word-bytes)
  33     (inst sub rdi n-word-bytes)
  34     (inst cmp rsp-tn rsi)
  35     (inst jmp :a DONE)
  36     (inst std)
  37     LOOP
  38     (inst movs :qword)
  39     (inst cmp rsp-tn rsi)
  40     (inst jmp :be LOOP)
  41     DONE
  42     (inst lea rsp-tn (make-ea :qword :base rdi :disp n-word-bytes))
  43     (inst sub rdi rsi)
  44     (loop for moved = moved-ptrs then (tn-ref-across moved)
  45           while moved
  46           do (inst add (tn-ref-tn moved) rdi))))
  47
  48 ;;; Push some values onto the stack, returning the start and number of values
  49 ;;; pushed as results. It is assumed that the Vals are wired to the standard
  50 ;;; argument locations. Nvals is the number of values to push.
  51 ;;;
  52 ;;; The generator cost is pseudo-random. We could get it right by defining a
  53 ;;; bogus SC that reflects the costs of the memory-to-memory moves for each
  54 ;;; operand, but this seems unworthwhile.
  55 (define-vop (push-values)
  56   (:args (vals :more t))
  57   (:temporary (:sc unsigned-reg :to (:result 0) :target start) temp)
  58   (:results (start) (count))
  59   (:info nvals)
  60   (:generator 20
  61     (move temp rsp-tn)                  ; WARN pointing 1 below
  62     (do ((val vals (tn-ref-across val)))
  63         ((null val))
  64       (inst push (tn-ref-tn val)))
  65     (move start temp)
  66     (inst mov count (fixnumize nvals))))
  67
  68 ;;; Push a list of values on the stack, returning Start and Count as used in
  69 ;;; unknown values continuations.
  70 (define-vop (values-list)
  71   (:args (arg :scs (descriptor-reg) :target list))
  72   (:arg-types list)
  73   (:policy :fast-safe)
  74   (:results (start :scs (any-reg))
  75             (count :scs (any-reg)))
  76   (:temporary (:sc descriptor-reg :from (:argument 0) :to (:result 1)) list)
  77   (:temporary (:sc descriptor-reg :to (:result 1)) nil-temp)
  78   (:temporary (:sc unsigned-reg :offset rax-offset :to (:result 1)) rax)
  79   (:vop-var vop)
  80   (:save-p :compute-only)
  81   (:generator 0
  82     (move list arg)
  83     (move start rsp-tn)                 ; WARN pointing 1 below
  84     (inst mov nil-temp nil-value)
  85
  86     LOOP
  87     (inst cmp list nil-temp)
  88     (inst jmp :e DONE)
  89     (pushw list cons-car-slot list-pointer-lowtag)
  90     (loadw list list cons-cdr-slot list-pointer-lowtag)
  91     (inst mov rax list)
  92     (inst and al-tn lowtag-mask)
  93     (inst cmp al-tn list-pointer-lowtag)
  94     (inst jmp :e LOOP)
  95     (error-call vop bogus-arg-to-values-list-error list)
  96
  97     DONE
  98     (inst mov count start)              ; start is high address
  99     (inst sub count rsp-tn)))           ; stackp is low address
 100
 101 ;;; Copy the more arg block to the top of the stack so we can use them
 102 ;;; as function arguments.
 103 ;;;
 104 ;;; Accepts a context as produced by more-arg-context; points to the first
 105 ;;; value on the stack, not 4 bytes above as in other contexts.
 106 ;;;
 107 ;;; Return a context that is 4 bytes above the first value, suitable for
 108 ;;; defining a new stack frame.
 109 (define-vop (%more-arg-values)
 110   (:args (context :scs (descriptor-reg any-reg) :target src)
 111          (skip :scs (any-reg immediate))
 112          (num :scs (any-reg) :target count))
 113   (:arg-types * positive-fixnum positive-fixnum)
 114   (:temporary (:sc any-reg :offset rsi-offset :from (:argument 0)) src)
 115   (:temporary (:sc descriptor-reg :offset rax-offset) temp)
 116   (:temporary (:sc unsigned-reg :offset rcx-offset) loop-index)
 117   (:results (start :scs (any-reg))
 118             (count :scs (any-reg)))
 119   (:generator 20
 120     (sc-case skip
 121       (immediate
 122        (cond ((zerop (tn-value skip))
 123               (move src context)
 124               (move count num))
 125              (t
 126               (inst lea src (make-ea :dword :base context
 127                                      :disp (- (* (tn-value skip)
 128                                                  n-word-bytes))))
 129               (move count num)
 130               (inst sub count (* (tn-value skip) n-word-bytes)))))
 131
 132       (any-reg
 133        (move src context)
 134        (inst sub src skip)
 135        (move count num)
 136        (inst sub count skip)))
 137
 138     (move loop-index count)
 139     (inst mov start rsp-tn)
 140     (inst jrcxz DONE)  ; check for 0 count?
 141
 142     (inst sub rsp-tn count)
 143     (inst sub src count)
 144
 145     LOOP
 146     (inst mov temp (make-ea :qword :base src :index loop-index))
 147     (inst sub loop-index n-word-bytes)
 148     (inst mov (make-ea :qword :base rsp-tn :index loop-index) temp)
 149     (inst jmp :nz LOOP)
 150
 151     DONE))
 152