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 ;;; The MOVE-ARG VOP is used for moving descriptor values into
  82 ;;; another frame for argument or known value passing.
  83 ;;;
  84 ;;; Note: It is not going to be possible to move a constant directly
  85 ;;; to another frame, except if the destination is a register and in
  86 ;;; this case the loading works out.
  87 (define-vop (move-arg)
  88   (:args (x :scs (any-reg descriptor-reg immediate) :target y
  89             :load-if (not (and (sc-is y any-reg descriptor-reg)
  90                                (sc-is x control-stack))))
  91          (fp :scs (any-reg)
  92              :load-if (not (sc-is y any-reg descriptor-reg))))
  93   (:results (y))
  94   (:generator 0
  95     (sc-case y
  96       ((any-reg descriptor-reg)
  97        (if (sc-is x immediate)
  98            (let ((val (encode-value-if-immediate x)))
  99              (if (zerop val)
 100                  (inst xor y y)
 101                  (inst mov y val)))
 102          (move y x)))
 103       ((control-stack)
 104        (let ((frame-offset (if (= (tn-offset fp) esp-offset)
 105                                ;; C-call
 106                                (tn-offset y)
 107                                ;; Lisp stack
 108                                (frame-word-offset (tn-offset y)))))
 109          (storew (encode-value-if-immediate x) fp frame-offset))))))
 110
 111 (define-move-vop move-arg :move-arg
 112   (any-reg descriptor-reg)
 113   (any-reg descriptor-reg))
 114 \f
 115 ;;;; moves and coercions
 116
 117 ;;; These MOVE-TO-WORD VOPs move a tagged integer to a raw full-word
 118 ;;; representation. Similarly, the MOVE-FROM-WORD VOPs converts a raw
 119 ;;; integer to a tagged bignum or fixnum.
 120
 121 ;;; Arg is a fixnum, so just shift it. We need a type restriction
 122 ;;; because some possible arg SCs (control-stack) overlap with
 123 ;;; possible bignum arg SCs.
 124 (define-vop (move-to-word/fixnum)
 125   (:args (x :scs (any-reg descriptor-reg) :target y
 126             :load-if (not (location= x y))))
 127   (:results (y :scs (signed-reg unsigned-reg)
 128                :load-if (not (location= x y))))
 129   (:arg-types tagged-num)
 130   (:note "fixnum untagging")
 131   (:generator 1
 132     (move y x)
 133     (inst sar y n-fixnum-tag-bits)))
 134 (define-move-vop move-to-word/fixnum :move
 135   (any-reg descriptor-reg) (signed-reg unsigned-reg))
 136
 137 ;;; Arg is a non-immediate constant, load it.
 138 (define-vop (move-to-word-c)
 139   (:args (x :scs (constant)))
 140   (:results (y :scs (signed-reg unsigned-reg)))
 141   (:note "constant load")
 142   (:generator 1
 143     (cond ((sb!c::tn-leaf x)
 144            (inst mov y (tn-value x)))
 145           (t
 146            (inst mov y x)
 147            (inst sar y n-fixnum-tag-bits)))))
 148 (define-move-vop move-to-word-c :move
 149   (constant) (signed-reg unsigned-reg))
 150
 151
 152 ;;; Arg is a fixnum or bignum, figure out which and load if necessary.
 153 (define-vop (move-to-word/integer)
 154   (:args (x :scs (descriptor-reg) :target eax))
 155   (:results (y :scs (signed-reg unsigned-reg)))
 156   (:note "integer to untagged word coercion")
 157   (:temporary (:sc unsigned-reg :offset eax-offset
 158                    :from (:argument 0) :to (:result 0) :target y) eax)
 159   (:generator 4
 160     (move eax x)
 161     (inst test al-tn fixnum-tag-mask)
 162     (inst jmp :z fixnum)
 163     (loadw y eax bignum-digits-offset other-pointer-lowtag)
 164     (inst jmp done)
 165     FIXNUM
 166     (inst sar eax n-fixnum-tag-bits)
 167     (move y eax)
 168     DONE))
 169 (define-move-vop move-to-word/integer :move
 170   (descriptor-reg) (signed-reg unsigned-reg))
 171
 172
 173 ;;; Result is a fixnum, so we can just shift. We need the result type
 174 ;;; restriction because of the control-stack ambiguity noted above.
 175 (define-vop (move-from-word/fixnum)
 176   (:args (x :scs (signed-reg unsigned-reg) :target y
 177             :load-if (not (location= x y))))
 178   (:results (y :scs (any-reg descriptor-reg)
 179                :load-if (not (location= x y))))
 180   (:result-types tagged-num)
 181   (:note "fixnum tagging")
 182   (:generator 1
 183     (cond ((and (sc-is x signed-reg unsigned-reg)
 184                 (not (location= x y)))
 185            ;; Uses 7 bytes, but faster on the Pentium
 186            (inst lea y (make-ea :dword :index x
 187                                 :scale (ash 1 n-fixnum-tag-bits))))
 188           (t
 189            ;; Uses: If x is a reg 2 + 3; if x = y uses only 3 bytes
 190            (move y x)
 191            (inst shl y n-fixnum-tag-bits)))))
 192 (define-move-vop move-from-word/fixnum :move
 193   (signed-reg unsigned-reg) (any-reg descriptor-reg))
 194
 195 ;;; Convert an untagged signed word to a lispobj -- fixnum or bignum
 196 ;;; as the case may be. Fixnum case inline, bignum case in an assembly
 197 ;;; routine.
 198 (define-vop (move-from-signed)
 199   (:args (x :scs (signed-reg unsigned-reg) :to :result))
 200   (:results (y :scs (any-reg descriptor-reg) :from :argument))
 201   (:note "signed word to integer coercion")
 202   ;; Worst case cost to make sure people know they may be number consing.
 203   (:generator 20
 204      (aver (not (location= x y)))
 205      (let ((done (gen-label)))
 206        (inst imul y x (ash 1 n-fixnum-tag-bits))
 207        (inst jmp :no done)
 208        (inst mov y x)
 209        (inst call (make-fixup (ecase (tn-offset y)
 210                                 (#.eax-offset 'alloc-signed-bignum-in-eax)
 211                                 (#.ebx-offset 'alloc-signed-bignum-in-ebx)
 212                                 (#.ecx-offset 'alloc-signed-bignum-in-ecx)
 213                                 (#.edx-offset 'alloc-signed-bignum-in-edx)
 214                                 (#.esi-offset 'alloc-signed-bignum-in-esi)
 215                                 (#.edi-offset 'alloc-signed-bignum-in-edi))
 216                               :assembly-routine))
 217        (emit-label done))))
 218 (define-move-vop move-from-signed :move
 219   (signed-reg) (descriptor-reg))
 220
 221 ;;; Convert an untagged unsigned word to a lispobj -- fixnum or bignum
 222 ;;; as the case may be. Fixnum case inline, bignum case in an assembly
 223 ;;; routine.
 224 (define-vop (move-from-unsigned)
 225   (:args (x :scs (signed-reg unsigned-reg) :to :result))
 226   (:results (y :scs (any-reg descriptor-reg) :from :argument))
 227   (:note "unsigned word to integer coercion")
 228   ;; Worst case cost to make sure people know they may be number consing.
 229   (:generator 20
 230     (aver (not (location= x y)))
 231     (let ((done (gen-label)))
 232       ;; The assembly routines test the sign flag from this one, so if
 233       ;; you change stuff here, make sure the sign flag doesn't get
 234       ;; overwritten before the CALL!
 235       (inst test x #.(ash lowtag-mask n-positive-fixnum-bits))
 236       ;; Faster but bigger then SHL Y 2. The cost of doing this speculatively
 237       ;; is noise compared to bignum consing if that is needed.
 238       (inst lea y (make-ea :dword :index x :scale (ash 1 n-fixnum-tag-bits)))
 239       (inst jmp :z done)
 240       (inst mov y x)
 241       (inst call (make-fixup (ecase (tn-offset y)
 242                                (#.eax-offset 'alloc-unsigned-bignum-in-eax)
 243                                (#.ebx-offset 'alloc-unsigned-bignum-in-ebx)
 244                                (#.ecx-offset 'alloc-unsigned-bignum-in-ecx)
 245                                (#.edx-offset 'alloc-unsigned-bignum-in-edx)
 246                                (#.edi-offset 'alloc-unsigned-bignum-in-edi)
 247                                (#.esi-offset 'alloc-unsigned-bignum-in-esi))
 248                              :assembly-routine))
 249       (emit-label done))))
 250 (define-move-vop move-from-unsigned :move
 251   (unsigned-reg) (descriptor-reg))
 252
 253 ;;; Move untagged numbers.
 254 (define-vop (word-move)
 255   (:args (x :scs (signed-reg unsigned-reg) :target y
 256             :load-if (not (location= x y))))
 257   (:results (y :scs (signed-reg unsigned-reg)
 258                :load-if
 259                (not (or (location= x y)
 260                         (and (sc-is x signed-reg unsigned-reg)
 261                              (sc-is y signed-stack unsigned-stack))))))
 262   (:effects)
 263   (:affected)
 264   (:note "word integer move")
 265   (:generator 0
 266     (move y x)))
 267 (define-move-vop word-move :move
 268   (signed-reg unsigned-reg) (signed-reg unsigned-reg))
 269
 270 ;;; Move untagged number arguments/return-values.
 271 (define-vop (move-word-arg)
 272   (:args (x :scs (signed-reg unsigned-reg) :target y)
 273          (fp :scs (any-reg)
 274              :load-if (not (sc-is y signed-reg unsigned-reg))))
 275   (:results (y))
 276   (:note "word integer argument move")
 277   (:generator 0
 278     (sc-case y
 279       ((signed-reg unsigned-reg)
 280        (move y x))
 281       ((signed-stack unsigned-stack)
 282        (if (= (tn-offset fp) esp-offset)
 283            (storew x fp (tn-offset y))  ; c-call
 284            (storew x fp (frame-word-offset (tn-offset y))))))))
 285 (define-move-vop move-word-arg :move-arg
 286   (descriptor-reg any-reg signed-reg unsigned-reg) (signed-reg unsigned-reg))
 287
 288 ;;; Use standard MOVE-ARG and coercion to move an untagged number
 289 ;;; to a descriptor passing location.
 290 (define-move-vop move-arg :move-arg
 291   (signed-reg unsigned-reg) (any-reg descriptor-reg))