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 n-fixnum-tag-bits)))
 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     (cond ((sb!c::tn-leaf x)
 164            (inst mov y (tn-value x)))
 165           (t
 166            (inst mov y x)
 167            (inst sar y n-fixnum-tag-bits)))))
 168 (define-move-vop move-to-word-c :move
 169   (constant) (signed-reg unsigned-reg))
 170
 171
 172 ;;; Arg is a fixnum or bignum, figure out which and load if necessary.
 173 (define-vop (move-to-word/integer)
 174   (:args (x :scs (descriptor-reg) :target eax))
 175   (:results (y :scs (signed-reg unsigned-reg)))
 176   (:note "integer to untagged word coercion")
 177   (:temporary (:sc unsigned-reg :offset eax-offset
 178                    :from (:argument 0) :to (:result 0) :target y) eax)
 179   (:generator 4
 180     (move eax x)
 181     (inst test al-tn fixnum-tag-mask)
 182     (inst jmp :z fixnum)
 183     (loadw y eax bignum-digits-offset other-pointer-lowtag)
 184     (inst jmp done)
 185     FIXNUM
 186     (inst sar eax n-fixnum-tag-bits)
 187     (move y eax)
 188     DONE))
 189 (define-move-vop move-to-word/integer :move
 190   (descriptor-reg) (signed-reg unsigned-reg))
 191
 192
 193 ;;; Result is a fixnum, so we can just shift. We need the result type
 194 ;;; restriction because of the control-stack ambiguity noted above.
 195 (define-vop (move-from-word/fixnum)
 196   (:args (x :scs (signed-reg unsigned-reg) :target y
 197             :load-if (not (location= x y))))
 198   (:results (y :scs (any-reg descriptor-reg)
 199                :load-if (not (location= x y))))
 200   (:result-types tagged-num)
 201   (:note "fixnum tagging")
 202   (:generator 1
 203     (cond ((and (sc-is x signed-reg unsigned-reg)
 204                 (not (location= x y)))
 205            ;; Uses 7 bytes, but faster on the Pentium
 206            (inst lea y (make-ea :dword :index x
 207                                 :scale (ash 1 n-fixnum-tag-bits))))
 208           (t
 209            ;; Uses: If x is a reg 2 + 3; if x = y uses only 3 bytes
 210            (move y x)
 211            (inst shl y n-fixnum-tag-bits)))))
 212 (define-move-vop move-from-word/fixnum :move
 213   (signed-reg unsigned-reg) (any-reg descriptor-reg))
 214
 215 ;;; Convert an untagged signed word to a lispobj -- fixnum or bignum
 216 ;;; as the case may be. Fixnum case inline, bignum case in an assembly
 217 ;;; routine.
 218 (define-vop (move-from-signed)
 219   (:args (x :scs (signed-reg unsigned-reg) :to :result))
 220   (:results (y :scs (any-reg descriptor-reg) :from :argument))
 221   (:note "signed word to integer coercion")
 222   ;; Worst case cost to make sure people know they may be number consing.
 223   (:generator 20
 224      (aver (not (location= x y)))
 225      (let ((done (gen-label)))
 226        (inst imul y x (ash 1 n-fixnum-tag-bits))
 227        (inst jmp :no done)
 228        (inst mov y x)
 229        (inst call (make-fixup (ecase (tn-offset y)
 230                                 (#.eax-offset 'alloc-signed-bignum-in-eax)
 231                                 (#.ebx-offset 'alloc-signed-bignum-in-ebx)
 232                                 (#.ecx-offset 'alloc-signed-bignum-in-ecx)
 233                                 (#.edx-offset 'alloc-signed-bignum-in-edx)
 234                                 (#.esi-offset 'alloc-signed-bignum-in-esi)
 235                                 (#.edi-offset 'alloc-signed-bignum-in-edi))
 236                               :assembly-routine))
 237        (emit-label done))))
 238 (define-move-vop move-from-signed :move
 239   (signed-reg) (descriptor-reg))
 240
 241 ;;; Convert an untagged unsigned word to a lispobj -- fixnum or bignum
 242 ;;; as the case may be. Fixnum case inline, bignum case in an assembly
 243 ;;; routine.
 244 (define-vop (move-from-unsigned)
 245   (:args (x :scs (signed-reg unsigned-reg) :to :result))
 246   (:results (y :scs (any-reg descriptor-reg) :from :argument))
 247   (:note "unsigned word to integer coercion")
 248   ;; Worst case cost to make sure people know they may be number consing.
 249   (:generator 20
 250     (aver (not (location= x y)))
 251     (let ((done (gen-label)))
 252       ;; The assembly routines test the sign flag from this one, so if
 253       ;; you change stuff here, make sure the sign flag doesn't get
 254       ;; overwritten before the CALL!
 255       (inst test x #.(ash lowtag-mask n-positive-fixnum-bits))
 256       ;; Faster but bigger then SHL Y 2. The cost of doing this speculatively
 257       ;; is noise compared to bignum consing if that is needed.
 258       (inst lea y (make-ea :dword :index x :scale (ash 1 n-fixnum-tag-bits)))
 259       (inst jmp :z done)
 260       (inst mov y x)
 261       (inst call (make-fixup (ecase (tn-offset y)
 262                                (#.eax-offset 'alloc-unsigned-bignum-in-eax)
 263                                (#.ebx-offset 'alloc-unsigned-bignum-in-ebx)
 264                                (#.ecx-offset 'alloc-unsigned-bignum-in-ecx)
 265                                (#.edx-offset 'alloc-unsigned-bignum-in-edx)
 266                                (#.edi-offset 'alloc-unsigned-bignum-in-edi)
 267                                (#.esi-offset 'alloc-unsigned-bignum-in-esi))
 268                              :assembly-routine))
 269       (emit-label done))))
 270 (define-move-vop move-from-unsigned :move
 271   (unsigned-reg) (descriptor-reg))
 272
 273 ;;; Move untagged numbers.
 274 (define-vop (word-move)
 275   (:args (x :scs (signed-reg unsigned-reg) :target y
 276             :load-if (not (location= x y))))
 277   (:results (y :scs (signed-reg unsigned-reg)
 278                :load-if
 279                (not (or (location= x y)
 280                         (and (sc-is x signed-reg unsigned-reg)
 281                              (sc-is y signed-stack unsigned-stack))))))
 282   (:effects)
 283   (:affected)
 284   (:note "word integer move")
 285   (:generator 0
 286     (move y x)))
 287 (define-move-vop word-move :move
 288   (signed-reg unsigned-reg) (signed-reg unsigned-reg))
 289
 290 ;;; Move untagged number arguments/return-values.
 291 (define-vop (move-word-arg)
 292   (:args (x :scs (signed-reg unsigned-reg) :target y)
 293          (fp :scs (any-reg) :load-if (not (sc-is y sap-reg))))
 294   (:results (y))
 295   (:note "word integer argument move")
 296   (:generator 0
 297     (sc-case y
 298       ((signed-reg unsigned-reg)
 299        (move y x))
 300       ((signed-stack unsigned-stack)
 301        (if (= (tn-offset fp) esp-offset)
 302            (storew x fp (tn-offset y))  ; c-call
 303            (storew x fp (frame-word-offset (tn-offset y))))))))
 304 (define-move-vop move-word-arg :move-arg
 305   (descriptor-reg any-reg signed-reg unsigned-reg) (signed-reg unsigned-reg))
 306
 307 ;;; Use standard MOVE-ARG and coercion to move an untagged number
 308 ;;; to a descriptor passing location.
 309 (define-move-vop move-arg :move-arg
 310   (signed-reg unsigned-reg) (any-reg descriptor-reg))