src/compiler/x86-64/system.lisp

   1 ;;;; x86 VM definitions of various system hacking operations
   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 \f
  14 ;;;; type frobbing VOPs
  15
  16 (define-vop (lowtag-of)
  17   (:translate lowtag-of)
  18   (:policy :fast-safe)
  19   (:args (object :scs (any-reg descriptor-reg control-stack)
  20                  :target result))
  21   (:results (result :scs (unsigned-reg)))
  22   (:result-types positive-fixnum)
  23   (:generator 1
  24     (move result object)
  25     (inst and result lowtag-mask)))
  26
  27 (define-vop (widetag-of)
  28   (:translate widetag-of)
  29   (:policy :fast-safe)
  30   (:args (object :scs (descriptor-reg)))
  31   (:temporary (:sc unsigned-reg :offset eax-offset :to (:result 0)) rax)
  32   (:results (result :scs (unsigned-reg)))
  33   (:result-types positive-fixnum)
  34   (:generator 6
  35     (inst mov rax object)
  36     (inst and al-tn lowtag-mask)
  37     (inst cmp al-tn other-pointer-lowtag)
  38     (inst jmp :e OTHER-PTR)
  39     (inst cmp al-tn fun-pointer-lowtag)
  40     (inst jmp :e FUNCTION-PTR)
  41
  42     ;; Pick off structures and list pointers.
  43     (inst test al-tn 1)
  44     (inst jmp :ne DONE)
  45
  46     ;; Pick off fixnums.
  47     (inst and al-tn 7)
  48     (inst jmp :e DONE)
  49
  50     ;; must be an other immediate
  51     (inst mov rax object)
  52     (inst jmp DONE)
  53
  54     FUNCTION-PTR
  55     (load-type al-tn object (- fun-pointer-lowtag))
  56     (inst jmp DONE)
  57
  58     OTHER-PTR
  59     (load-type al-tn object (- other-pointer-lowtag))
  60
  61     DONE
  62     (inst movzx result al-tn)))
  63 \f
  64 (define-vop (fun-subtype)
  65   (:translate fun-subtype)
  66   (:policy :fast-safe)
  67   (:args (function :scs (descriptor-reg)))
  68   (:temporary (:sc byte-reg :from (:eval 0) :to (:eval 1)) temp)
  69   (:results (result :scs (unsigned-reg)))
  70   (:result-types positive-fixnum)
  71   (:generator 6
  72     (load-type temp function (- fun-pointer-lowtag))
  73     (inst movzx result temp)))
  74
  75 (define-vop (set-fun-subtype)
  76   (:translate (setf fun-subtype))
  77   (:policy :fast-safe)
  78   (:args (type :scs (unsigned-reg) :target eax)
  79          (function :scs (descriptor-reg)))
  80   (:arg-types positive-fixnum *)
  81   (:temporary (:sc unsigned-reg :offset rax-offset :from (:argument 0)
  82                    :to (:result 0) :target result)
  83               eax)
  84   (:results (result :scs (unsigned-reg)))
  85   (:result-types positive-fixnum)
  86   (:generator 6
  87     (move eax type)
  88     (inst mov
  89           (make-ea :byte :base function :disp (- fun-pointer-lowtag))
  90           al-tn)
  91     (move result eax)))
  92
  93 (define-vop (get-header-data)
  94   (:translate get-header-data)
  95   (:policy :fast-safe)
  96   (:args (x :scs (descriptor-reg)))
  97   (:results (res :scs (unsigned-reg)))
  98   (:result-types positive-fixnum)
  99   (:generator 6
 100     (loadw res x 0 other-pointer-lowtag)
 101     (inst shr res n-widetag-bits)))
 102
 103 (define-vop (get-closure-length)
 104   (:translate get-closure-length)
 105   (:policy :fast-safe)
 106   (:args (x :scs (descriptor-reg)))
 107   (:results (res :scs (unsigned-reg)))
 108   (:result-types positive-fixnum)
 109   (:generator 6
 110     (loadw res x 0 fun-pointer-lowtag)
 111     (inst shr res n-widetag-bits)))
 112
 113 (define-vop (set-header-data)
 114   (:translate set-header-data)
 115   (:policy :fast-safe)
 116   (:args (x :scs (descriptor-reg) :target res :to (:result 0))
 117          (data :scs (any-reg) :target eax))
 118   (:arg-types * positive-fixnum)
 119   (:results (res :scs (descriptor-reg)))
 120   (:temporary (:sc unsigned-reg :offset eax-offset
 121                    :from (:argument 1) :to (:result 0)) eax)
 122   (:generator 6
 123     (move eax data)
 124     (inst shl eax (- n-widetag-bits n-fixnum-tag-bits))
 125     (inst mov al-tn (make-ea :byte :base x :disp (- other-pointer-lowtag)))
 126     (storew eax x 0 other-pointer-lowtag)
 127     (move res x)))
 128 \f
 129 (define-vop (pointer-hash)
 130   (:translate pointer-hash)
 131   (:args (ptr :scs (any-reg descriptor-reg) :target res))
 132   (:results (res :scs (any-reg descriptor-reg)))
 133   (:policy :fast-safe)
 134   (:generator 1
 135     (move res ptr)
 136     ;; Mask the lowtag, and shift the whole address into a positive
 137     ;; fixnum.
 138     (inst and res (lognot lowtag-mask))
 139     (inst shr res 1)))
 140
 141 (define-vop (make-other-immediate-type)
 142   (:args (val :scs (any-reg descriptor-reg) :target res)
 143          (type :scs (unsigned-reg immediate)))
 144   (:results (res :scs (any-reg descriptor-reg) :from (:argument 0)))
 145   (:generator 2
 146     (move res val)
 147     (inst shl res (- n-widetag-bits n-fixnum-tag-bits))
 148     (inst or res (sc-case type
 149                    (unsigned-reg type)
 150                    (immediate (tn-value type))))))
 151 \f
 152 ;;;; allocation
 153
 154 (define-vop (dynamic-space-free-pointer)
 155   (:results (int :scs (sap-reg)))
 156   (:result-types system-area-pointer)
 157   (:translate dynamic-space-free-pointer)
 158   (:policy :fast-safe)
 159   (:generator 1
 160     (load-symbol-value int *allocation-pointer*)))
 161
 162 (define-vop (binding-stack-pointer-sap)
 163   (:results (int :scs (sap-reg)))
 164   (:result-types system-area-pointer)
 165   (:translate binding-stack-pointer-sap)
 166   (:policy :fast-safe)
 167   (:generator 1
 168     (load-binding-stack-pointer int)))
 169
 170 (defknown (setf binding-stack-pointer-sap)
 171     (system-area-pointer) system-area-pointer ())
 172
 173 (define-vop (set-binding-stack-pointer-sap)
 174   (:args (new-value :scs (sap-reg) :target int))
 175   (:arg-types system-area-pointer)
 176   (:results (int :scs (sap-reg)))
 177   (:result-types system-area-pointer)
 178   (:translate (setf binding-stack-pointer-sap))
 179   (:policy :fast-safe)
 180   (:generator 1
 181     (store-binding-stack-pointer new-value)
 182     (move int new-value)))
 183
 184 (define-vop (control-stack-pointer-sap)
 185   (:results (int :scs (sap-reg)))
 186   (:result-types system-area-pointer)
 187   (:translate control-stack-pointer-sap)
 188   (:policy :fast-safe)
 189   (:generator 1
 190     (move int rsp-tn)))
 191 \f
 192 ;;;; code object frobbing
 193
 194 (define-vop (code-instructions)
 195   (:translate code-instructions)
 196   (:policy :fast-safe)
 197   (:args (code :scs (descriptor-reg) :to (:result 0)))
 198   (:results (sap :scs (sap-reg) :from (:argument 0)))
 199   (:result-types system-area-pointer)
 200   (:generator 10
 201     (loadw sap code 0 other-pointer-lowtag)
 202     (inst shr sap n-widetag-bits)
 203     (inst lea sap (make-ea :byte :base code :index sap
 204                            :scale n-word-bytes
 205                            :disp (- other-pointer-lowtag)))))
 206
 207 (define-vop (compute-fun)
 208   (:args (code :scs (descriptor-reg) :to (:result 0))
 209          (offset :scs (signed-reg unsigned-reg) :to (:result 0)))
 210   (:arg-types * positive-fixnum)
 211   (:results (func :scs (descriptor-reg) :from (:argument 0)))
 212   (:generator 10
 213     (loadw func code 0 other-pointer-lowtag)
 214     (inst shr func n-widetag-bits)
 215     (inst lea func
 216           (make-ea :byte :base offset :index func
 217                    :scale n-word-bytes
 218                    :disp (- fun-pointer-lowtag other-pointer-lowtag)))
 219     (inst add func code)))
 220
 221 (define-vop (%simple-fun-self)
 222   (:policy :fast-safe)
 223   (:translate %simple-fun-self)
 224   (:args (function :scs (descriptor-reg)))
 225   (:results (result :scs (descriptor-reg)))
 226   (:generator 3
 227     (loadw result function simple-fun-self-slot fun-pointer-lowtag)
 228     (inst lea result
 229           (make-ea :byte :base result
 230                    :disp (- fun-pointer-lowtag
 231                             (* simple-fun-code-offset n-word-bytes))))))
 232
 233 ;;; The closure function slot is a pointer to raw code on X86 instead
 234 ;;; of a pointer to the code function object itself. This VOP is used
 235 ;;; to reference the function object given the closure object.
 236 (define-source-transform %closure-fun (closure)
 237   `(%simple-fun-self ,closure))
 238
 239 (define-vop (%set-fun-self)
 240   (:policy :fast-safe)
 241   (:translate (setf %simple-fun-self))
 242   (:args (new-self :scs (descriptor-reg) :target result :to :result)
 243          (function :scs (descriptor-reg) :to :result))
 244   (:temporary (:sc any-reg :from (:argument 0) :to :result) temp)
 245   (:results (result :scs (descriptor-reg)))
 246   (:generator 3
 247     (inst lea temp
 248           (make-ea :byte :base new-self
 249                    :disp (- (ash simple-fun-code-offset word-shift)
 250                             fun-pointer-lowtag)))
 251     (storew temp function simple-fun-self-slot fun-pointer-lowtag)
 252     (move result new-self)))
 253 \f
 254 ;;;; other miscellaneous VOPs
 255
 256 (defknown sb!unix::receive-pending-interrupt () (values))
 257 (define-vop (sb!unix::receive-pending-interrupt)
 258   (:policy :fast-safe)
 259   (:translate sb!unix::receive-pending-interrupt)
 260   (:generator 1
 261     (inst break pending-interrupt-trap)))
 262
 263 #!+sb-thread
 264 (defknown current-thread-offset-sap ((unsigned-byte 64))
 265   system-area-pointer (flushable))
 266
 267 #!+sb-thread
 268 (define-vop (current-thread-offset-sap)
 269   (:results (sap :scs (sap-reg)))
 270   (:result-types system-area-pointer)
 271   (:translate current-thread-offset-sap)
 272   (:args (n :scs (unsigned-reg) :target sap))
 273   (:arg-types unsigned-num)
 274   (:policy :fast-safe)
 275   (:generator 2
 276     (inst mov sap
 277           (make-ea :qword :base thread-base-tn :disp 0 :index n :scale 8))))
 278
 279 (define-vop (halt)
 280   (:generator 1
 281     (inst break halt-trap)))
 282
 283 (defknown float-wait () (values))
 284 (define-vop (float-wait)
 285   (:policy :fast-safe)
 286   (:translate float-wait)
 287   (:vop-var vop)
 288   (:save-p :compute-only)
 289   (:generator 1
 290     (note-next-instruction vop :internal-error)
 291     (inst wait)))
 292 \f
 293 ;;;; Miscellany
 294
 295 ;;; the RDTSC instruction (present on Pentium processors and
 296 ;;; successors) allows you to access the time-stamp counter, a 64-bit
 297 ;;; model-specific register that counts executed cycles. The
 298 ;;; instruction returns the low cycle count in EAX and high cycle
 299 ;;; count in EDX.
 300 ;;;
 301 ;;; In order to obtain more significant results on out-of-order
 302 ;;; processors (such as the Pentium II and later), we issue a
 303 ;;; serializing CPUID instruction before and after reading the cycle
 304 ;;; counter. This instruction is used for its side effect of emptying
 305 ;;; the processor pipeline, to ensure that the RDTSC instruction is
 306 ;;; executed once all pending instructions have been completed and
 307 ;;; before any others. CPUID writes to EBX and ECX in addition to EAX
 308 ;;; and EDX, so they need to be added as temporaries.
 309 ;;;
 310 ;;; Note that cache effects mean that the cycle count can vary for
 311 ;;; different executions of the same code (it counts cycles, not
 312 ;;; retired instructions). Furthermore, the results are per-processor
 313 ;;; and not per-process, so are unreliable on multiprocessor machines
 314 ;;; where processes can migrate between processors.
 315 ;;;
 316 ;;; This method of obtaining a cycle count has the advantage of being
 317 ;;; very fast (around 20 cycles), and of not requiring a system call.
 318 ;;; However, you need to know your processor's clock speed to translate
 319 ;;; this into real execution time.
 320 ;;;
 321 ;;; FIXME: This about the WITH-CYCLE-COUNTER interface a bit, and then
 322 ;;; perhaps export it from SB-SYS.
 323
 324 (defknown %read-cycle-counter () (values (unsigned-byte 32) (unsigned-byte 32)) ())
 325
 326 (define-vop (%read-cycle-counter)
 327   (:policy :fast-safe)
 328   (:translate %read-cycle-counter)
 329   (:temporary (:sc unsigned-reg :offset eax-offset :target lo) eax)
 330   (:temporary (:sc unsigned-reg :offset edx-offset :target hi) edx)
 331   (:temporary (:sc unsigned-reg :offset ebx-offset) ebx)
 332   (:temporary (:sc unsigned-reg :offset ecx-offset) ecx)
 333   (:ignore ebx ecx)
 334   (:results (hi :scs (unsigned-reg))
 335             (lo :scs (unsigned-reg)))
 336   (:result-types unsigned-num unsigned-num)
 337   (:generator 5
 338      (zeroize eax)
 339      ;; Intel docs seem quite consistent on only using CPUID before RDTSC,
 340      ;; not both before and after. Go figure.
 341      (inst cpuid)
 342      (inst rdtsc)
 343      (move lo eax)
 344      (move hi edx)))
 345
 346 (defmacro with-cycle-counter (&body body)
 347   "Returns the primary value of BODY as the primary value, and the
 348 number of CPU cycles elapsed as secondary value. EXPERIMENTAL."
 349   (with-unique-names (hi0 hi1 lo0 lo1)
 350     `(multiple-value-bind (,hi0 ,lo0) (%read-cycle-counter)
 351        (values (locally ,@body)
 352                (multiple-value-bind (,hi1 ,lo1) (%read-cycle-counter)
 353                  (+ (ash (- ,hi1 ,hi0) 32)
 354                     (- ,lo1 ,lo0)))))))
 355
 356 #!+sb-dyncount
 357 (define-vop (count-me)
 358   (:args (count-vector :scs (descriptor-reg)))
 359   (:info index)
 360   (:generator 0
 361     (inst inc (make-ea :qword :base count-vector
 362                        :disp (- (* (+ vector-data-offset index) n-word-bytes)
 363                                 other-pointer-lowtag)))))