src/compiler/x86/move.lisp

   1 ;;;; the x86 VM definition of operand loading/saving and the MOVE vop
   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-move-fun (load-immediate 1) (vop x y)
  15   ((immediate)
  16    (any-reg descriptor-reg))
  17   (let ((val (encode-value-if-immediate x)))
  18     (if (zerop val)
  19         (inst xor y y)
  20         (inst mov y val))))
  21
  22 (define-move-fun (load-number 1) (vop x y)
  23   ((immediate) (signed-reg unsigned-reg))
  24   (let ((val (tn-value x)))
  25     (if (zerop val)
  26         (inst xor y y)
  27         (inst mov y val))))
  28
  29 (define-move-fun (load-character 1) (vop x y)
  30   ((immediate) (character-reg))
  31   (inst mov y (char-code (tn-value x))))
  32
  33 (define-move-fun (load-system-area-pointer 1) (vop x y)
  34   ((immediate) (sap-reg))
  35   (inst mov y (sap-int (tn-value x))))
  36
  37 (define-move-fun (load-constant 5) (vop x y)
  38   ((constant) (descriptor-reg any-reg))
  39   (inst mov y x))
  40
  41 (define-move-fun (load-stack 5) (vop x y)
  42   ((control-stack) (any-reg descriptor-reg)
  43    (character-stack) (character-reg)
  44    (sap-stack) (sap-reg)
  45    (signed-stack) (signed-reg)
  46    (unsigned-stack) (unsigned-reg))
  47   (inst mov y x))
  48
  49 (define-move-fun (store-stack 5) (vop x y)
  50   ((any-reg descriptor-reg) (control-stack)
  51    (character-reg) (character-stack)
  52    (sap-reg) (sap-stack)
  53    (signed-reg) (signed-stack)
  54    (unsigned-reg) (unsigned-stack))
  55   (inst mov y x))
  56 \f
  57 ;;;; the MOVE VOP
  58 (define-vop (move)
  59   (:args (x :scs (any-reg descriptor-reg immediate) :target y
  60             :load-if (not (location= x y))))
  61   (:results (y :scs (any-reg descriptor-reg)
  62                :load-if
  63                (not (or (location= x y)
  64                         (and (sc-is x any-reg descriptor-reg immediate)
  65                              (sc-is y control-stack))))))
  66   (:effects)
  67   (:affected)
  68   (:generator 0
  69     (if (and (sc-is x immediate)
  70              (sc-is y any-reg descriptor-reg control-stack))
  71         (let ((val (encode-value-if-immediate x)))
  72           (if (and (zerop val) (sc-is y any-reg descriptor-reg))
  73               (inst xor y y)
  74               (inst mov y val)))
  75       (move y x))))
  76
  77 (define-move-vop move :move
  78   (any-reg descriptor-reg immediate)
  79   (any-reg descriptor-reg))
  80
  81 ;;; Make MOVE the check VOP for T so that type check generation
  82 ;;; doesn't think it is a hairy type. This also allows checking of a
  83 ;;; few of the values in a continuation to fall out.
  84 (primitive-type-vop move (:check) t)
  85
  86 ;;; The MOVE-ARG VOP is used for moving descriptor values into
  87 ;;; another frame for argument or known value passing.
  88 ;;;
  89 ;;; Note: It is not going to be possible to move a constant directly
  90 ;;; to another frame, except if the destination is a register and in
  91 ;;; this case the loading works out.
  92 (define-vop (move-arg)
  93   (:args (x :scs (any-reg descriptor-reg immediate) :target y
  94             :load-if (not (and (sc-is y any-reg descriptor-reg)
  95                                (sc-is x control-stack))))
  96          (fp :scs (any-reg)
  97              :load-if (not (sc-is y any-reg descriptor-reg))))
  98   (:results (y))
  99   (:generator 0
 100     (sc-case y
 101       ((any-reg descriptor-reg)
 102        (if (sc-is x immediate)
 103            (let ((val (encode-value-if-immediate x)))
 104              (if (zerop val)
 105                  (inst xor y y)
 106                  (inst mov y val)))
 107          (move y x)))
 108       ((control-stack)
 109        (let ((frame-offset (if (= (tn-offset fp) esp-offset)
 110                                ;; C-call
 111                                (tn-offset y)
 112                                ;; Lisp stack
 113                                (frame-word-offset (tn-offset y)))))
 114          (storew (encode-value-if-immediate x) fp frame-offset))))))
 115
 116 (define-move-vop move-arg :move-arg
 117   (any-reg descriptor-reg)
 118   (any-reg descriptor-reg))
 119 \f
 120 ;;;; ILLEGAL-MOVE
 121
 122 ;;; This VOP exists just to begin the lifetime of a TN that couldn't
 123 ;;; be written legally due to a type error. An error is signalled
 124 ;;; before this VOP is so we don't need to do anything (not that there
 125 ;;; would be anything sensible to do anyway.)
 126 (define-vop (illegal-move)
 127   (:args (x) (type))
 128   (:results (y))
 129   (:ignore y)
 130   (:vop-var vop)
 131   (:save-p :compute-only)
 132   (:generator 666
 133     (error-call vop object-not-type-error x type)))
 134 \f
 135 ;;;; moves and coercions
 136
 137 ;;; These MOVE-TO-WORD VOPs move a tagged integer to a raw full-word
 138 ;;; representation. Similarly, the MOVE-FROM-WORD VOPs converts a raw
 139 ;;; integer to a tagged bignum or fixnum.
 140
 141 ;;; Arg is a fixnum, so just shift it. We need a type restriction
 142 ;;; because some possible arg SCs (control-stack) overlap with
 143 ;;; possible bignum arg SCs.
 144 (define-vop (move-to-word/fixnum)
 145   (:args (x :scs (any-reg descriptor-reg) :target y
 146             :load-if (not (location= x y))))
 147   (:results (y :scs (signed-reg unsigned-reg)
 148                :load-if (not (location= x y))))
 149   (:arg-types tagged-num)
 150   (:note "fixnum untagging")
 151   (:generator 1
 152     (move y x)
 153     (inst sar y 2)))
 154 (define-move-vop move-to-word/fixnum :move
 155   (any-reg descriptor-reg) (signed-reg unsigned-reg))
 156
 157 ;;; Arg is a non-immediate constant, load it.
 158 (define-vop (move-to-word-c)
 159   (:args (x :scs (constant)))
 160   (:results (y :scs (signed-reg unsigned-reg)))
 161   (:note "constant load")
 162   (:generator 1
 163     (inst mov y (tn-value x))))
 164 (define-move-vop move-to-word-c :move
 165   (constant) (signed-reg unsigned-reg))
 166
 167
 168 ;;; Arg is a fixnum or bignum, figure out which and load if necessary.
 169 (define-vop (move-to-word/integer)
 170   (:args (x :scs (descriptor-reg) :target eax))
 171   (:results (y :scs (signed-reg unsigned-reg)))
 172   (:note "integer to untagged word coercion")
 173   (:temporary (:sc unsigned-reg :offset eax-offset
 174                    :from (:argument 0) :to (:result 0) :target y) eax)
 175   (:generator 4
 176     (move eax x)
 177     (inst test al-tn 3)
 178     (inst jmp :z fixnum)
 179     (loadw y eax bignum-digits-offset other-pointer-lowtag)
 180     (inst jmp done)
 181     FIXNUM
 182     (inst sar eax 2)
 183     (move y eax)
 184     DONE))
 185 (define-move-vop move-to-word/integer :move
 186   (descriptor-reg) (signed-reg unsigned-reg))
 187
 188
 189 ;;; Result is a fixnum, so we can just shift. We need the result type
 190 ;;; restriction because of the control-stack ambiguity noted above.
 191 (define-vop (move-from-word/fixnum)
 192   (:args (x :scs (signed-reg unsigned-reg) :target y
 193             :load-if (not (location= x y))))
 194   (:results (y :scs (any-reg descriptor-reg)
 195                :load-if (not (location= x y))))
 196   (:result-types tagged-num)
 197   (:note "fixnum tagging")
 198   (:generator 1
 199     (cond ((and (sc-is x signed-reg unsigned-reg)
 200                 (not (location= x y)))
 201            ;; Uses 7 bytes, but faster on the Pentium
 202            (inst lea y (make-ea :dword :index x :scale 4)))
 203           (t
 204            ;; Uses: If x is a reg 2 + 3; if x = y uses only 3 bytes
 205            (move y x)
 206            (inst shl y 2)))))
 207 (define-move-vop move-from-word/fixnum :move
 208   (signed-reg unsigned-reg) (any-reg descriptor-reg))
 209
 210 ;;; Convert an untagged signed word to a lispobj -- fixnum or bignum
 211 ;;; as the case may be. Fixnum case inline, bignum case in an assembly
 212 ;;; routine.
 213 (define-vop (move-from-signed)
 214   (:args (x :scs (signed-reg unsigned-reg) :to :result))
 215   (:results (y :scs (any-reg descriptor-reg) :from :argument))
 216   (:note "signed word to integer coercion")
 217   ;; Worst case cost to make sure people know they may be number consing.
 218   (:generator 20
 219      (aver (not (location= x y)))
 220      (let ((done (gen-label)))
 221        (inst imul y x (ash 1 n-fixnum-tag-bits))
 222        (inst jmp :no done)
 223        (inst mov y x)
 224        (inst call (make-fixup (ecase (tn-offset y)
 225                                 (#.eax-offset 'alloc-signed-bignum-in-eax)
 226                                 (#.ebx-offset 'alloc-signed-bignum-in-ebx)
 227                                 (#.ecx-offset 'alloc-signed-bignum-in-ecx)
 228                                 (#.edx-offset 'alloc-signed-bignum-in-edx)
 229                                 (#.esi-offset 'alloc-signed-bignum-in-esi)
 230                                 (#.edi-offset 'alloc-signed-bignum-in-edi))
 231                               :assembly-routine))
 232        (emit-label done))))
 233 (define-move-vop move-from-signed :move
 234   (signed-reg) (descriptor-reg))
 235
 236 ;;; Convert an untagged unsigned word to a lispobj -- fixnum or bignum
 237 ;;; as the case may be. Fixnum case inline, bignum case in an assembly
 238 ;;; routine.
 239 (define-vop (move-from-unsigned)
 240   (:args (x :scs (signed-reg unsigned-reg) :to :result))
 241   (:results (y :scs (any-reg descriptor-reg) :from :argument))
 242   (:note "unsigned word to integer coercion")
 243   ;; Worst case cost to make sure people know they may be number consing.
 244   (:generator 20
 245     (aver (not (location= x y)))
 246     (let ((done (gen-label)))
 247       ;; The assembly routines test the sign flag from this one, so if
 248       ;; you change stuff here, make sure the sign flag doesn't get
 249       ;; overwritten before the CALL!
 250       (inst test x #xe0000000)
 251       ;; Faster but bigger then SHL Y 2. The cost of doing this speculatively
 252       ;; is noise compared to bignum consing if that is needed.
 253       (inst lea y (make-ea :dword :index x :scale 4))
 254       (inst jmp :z done)
 255       (inst mov y x)
 256       (inst call (make-fixup (ecase (tn-offset y)
 257                                (#.eax-offset 'alloc-unsigned-bignum-in-eax)
 258                                (#.ebx-offset 'alloc-unsigned-bignum-in-ebx)
 259                                (#.ecx-offset 'alloc-unsigned-bignum-in-ecx)
 260                                (#.edx-offset 'alloc-unsigned-bignum-in-edx)
 261                                (#.edi-offset 'alloc-unsigned-bignum-in-edi)
 262                                (#.esi-offset 'alloc-unsigned-bignum-in-esi))
 263                              :assembly-routine))
 264       (emit-label done))))
 265 (define-move-vop move-from-unsigned :move
 266   (unsigned-reg) (descriptor-reg))
 267
 268 ;;; Move untagged numbers.
 269 (define-vop (word-move)
 270   (:args (x :scs (signed-reg unsigned-reg) :target y
 271             :load-if (not (location= x y))))
 272   (:results (y :scs (signed-reg unsigned-reg)
 273                :load-if
 274                (not (or (location= x y)
 275                         (and (sc-is x signed-reg unsigned-reg)
 276                              (sc-is y signed-stack unsigned-stack))))))
 277   (:effects)
 278   (:affected)
 279   (:note "word integer move")
 280   (:generator 0
 281     (move y x)))
 282 (define-move-vop word-move :move
 283   (signed-reg unsigned-reg) (signed-reg unsigned-reg))
 284
 285 ;;; Move untagged number arguments/return-values.
 286 (define-vop (move-word-arg)
 287   (:args (x :scs (signed-reg unsigned-reg) :target y)
 288          (fp :scs (any-reg) :load-if (not (sc-is y sap-reg))))
 289   (:results (y))
 290   (:note "word integer argument move")
 291   (:generator 0
 292     (sc-case y
 293       ((signed-reg unsigned-reg)
 294        (move y x))
 295       ((signed-stack unsigned-stack)
 296        (if (= (tn-offset fp) esp-offset)
 297            (storew x fp (tn-offset y))  ; c-call
 298            (storew x fp (frame-word-offset (tn-offset y))))))))
 299 (define-move-vop move-word-arg :move-arg
 300   (descriptor-reg any-reg signed-reg unsigned-reg) (signed-reg unsigned-reg))
 301
 302 ;;; Use standard MOVE-ARG and coercion to move an untagged number
 303 ;;; to a descriptor passing location.
 304 (define-move-vop move-arg :move-arg
 305   (signed-reg unsigned-reg) (any-reg descriptor-reg))