src/compiler/x86/parms.lisp

   1 ;;;; This file contains some parameterizations of various VM
   2 ;;;; attributes for the x86. This file is separate from other stuff so
   3 ;;;; that it can be compiled and loaded earlier.
   4
   5 ;;;; This software is part of the SBCL system. See the README file for
   6 ;;;; more information.
   7 ;;;;
   8 ;;;; This software is derived from the CMU CL system, which was
   9 ;;;; written at Carnegie Mellon University and released into the
  10 ;;;; public domain. The software is in the public domain and is
  11 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  12 ;;;; files for more information.
  13
  14 (in-package "SB!VM")
  15
  16 ;;; ### Note: we simultaneously use ``word'' to mean a 32 bit quantity
  17 ;;; and a 16 bit quantity depending on context. This is because Intel
  18 ;;; insists on calling 16 bit things words and 32 bit things
  19 ;;; double-words (or dwords). Therefore, in the instruction definition
  20 ;;; and register specs, we use the Intel convention. But whenever we
  21 ;;; are talking about stuff the rest of the lisp system might be
  22 ;;; interested in, we use ``word'' to mean the size of a descriptor
  23 ;;; object, which is 32 bits.
  24 \f
  25 ;;;; machine architecture parameters
  26
  27 ;;; the number of bits per word, where a word holds one lisp descriptor
  28 (def!constant n-word-bits 32)
  29
  30 ;;; the natural width of a machine word (as seen in e.g. register width,
  31 ;;; address space)
  32 (def!constant n-machine-word-bits 32)
  33
  34 ;;; the number of bits per byte, where a byte is the smallest
  35 ;;; addressable object
  36 (def!constant n-byte-bits 8)
  37
  38 (def!constant float-sign-shift 31)
  39
  40 ;;; comment from CMU CL:
  41 ;;;   These values were taken from the alpha code. The values for
  42 ;;;   bias and exponent min/max are not the same as shown in the 486 book.
  43 ;;;   They may be correct for how Python uses them.
  44 (def!constant single-float-bias 126)    ; Intel says 127.
  45 (defconstant-eqx single-float-exponent-byte    (byte 8 23) #'equalp)
  46 (defconstant-eqx single-float-significand-byte (byte 23 0) #'equalp)
  47 ;;; comment from CMU CL:
  48 ;;;   The 486 book shows the exponent range -126 to +127. The Lisp
  49 ;;;   code that uses these values seems to want already biased numbers.
  50 (def!constant single-float-normal-exponent-min 1)
  51 (def!constant single-float-normal-exponent-max 254)
  52 (def!constant single-float-hidden-bit (ash 1 23))
  53 (def!constant single-float-trapping-nan-bit (ash 1 22))
  54
  55 (def!constant double-float-bias 1022)
  56 (defconstant-eqx double-float-exponent-byte    (byte 11 20) #'equalp)
  57 (defconstant-eqx double-float-significand-byte (byte 20 0)  #'equalp)
  58 (def!constant double-float-normal-exponent-min 1)
  59 (def!constant double-float-normal-exponent-max #x7FE)
  60 (def!constant double-float-hidden-bit (ash 1 20))
  61 (def!constant double-float-trapping-nan-bit (ash 1 19))
  62
  63 (def!constant long-float-bias 16382)
  64 (defconstant-eqx long-float-exponent-byte    (byte 15 0) #'equalp)
  65 (defconstant-eqx long-float-significand-byte (byte 31 0) #'equalp)
  66 (def!constant long-float-normal-exponent-min 1)
  67 (def!constant long-float-normal-exponent-max #x7FFE)
  68 (def!constant long-float-hidden-bit (ash 1 31))         ; actually not hidden
  69 (def!constant long-float-trapping-nan-bit (ash 1 30))
  70
  71 (def!constant single-float-digits
  72   (+ (byte-size single-float-significand-byte) 1))
  73
  74 (def!constant double-float-digits
  75   (+ (byte-size double-float-significand-byte) n-word-bits 1))
  76
  77 (def!constant long-float-digits
  78   (+ (byte-size long-float-significand-byte) n-word-bits 1))
  79
  80 ;;; pfw -- from i486 microprocessor programmer's reference manual
  81 (def!constant float-invalid-trap-bit       (ash 1 0))
  82 (def!constant float-denormal-trap-bit       (ash 1 1))
  83 (def!constant float-divide-by-zero-trap-bit (ash 1 2))
  84 (def!constant float-overflow-trap-bit       (ash 1 3))
  85 (def!constant float-underflow-trap-bit      (ash 1 4))
  86 (def!constant float-inexact-trap-bit       (ash 1 5))
  87
  88 (def!constant float-round-to-nearest  0)
  89 (def!constant float-round-to-negative 1)
  90 (def!constant float-round-to-positive 2)
  91 (def!constant float-round-to-zero     3)
  92
  93 (def!constant float-precision-24-bit 0)
  94 (def!constant float-precision-53-bit 2)
  95 (def!constant float-precision-64-bit 3)
  96
  97 (defconstant-eqx float-rounding-mode     (byte 2 10) #'equalp)
  98 (defconstant-eqx float-sticky-bits       (byte 6 16) #'equalp)
  99 (defconstant-eqx float-traps-byte        (byte 6  0) #'equalp)
 100 (defconstant-eqx float-exceptions-byte   (byte 6 16) #'equalp)
 101 (defconstant-eqx float-precision-control (byte 2  8) #'equalp)
 102 (def!constant float-fast-bit 0) ; no fast mode on x86
 103 \f
 104 ;;;; description of the target address space
 105
 106 ;;; where to put the different spaces
 107 ;;;
 108 ;;; Note: Mostly these values are black magic, inherited from CMU CL
 109 ;;; without any documentation. However, there were a few explanatory
 110 ;;; comments in the CMU CL sources:
 111 ;;;   * On Linux,
 112 ;;;     ** The space 0x08000000-0x10000000 is "C program and memory allocation".
 113 ;;;     ** The space 0x40000000-0x48000000 is reserved for shared libs.
 114 ;;;     ** The space >0xE0000000 is "C stack - Alien stack".
 115 ;;;   * On FreeBSD,
 116 ;;;     ** The space 0x0E000000-0x10000000 is "Foreign segment".
 117 ;;;     ** The space 0x20000000-0x30000000 is reserved for shared libs.
 118 ;;; And there have been some changes since the fork from CMU CL:
 119 ;;;   * The OpenBSD port is new since the fork. We started with
 120 ;;;     the FreeBSD address map, which actually worked until the
 121 ;;;     Alpha port patches, for reasons which in retrospect are rather
 122 ;;;     mysterious. After the Alpha port patches were added, the
 123 ;;;     OpenBSD port suffered memory corruption problems. While
 124 ;;;     debugging those, it was discovered that src/runtime/trymap
 125 ;;;     failed for the control stack region #x40000000-#x47fff000.
 126 ;;;     After the control stack was moved upward out of this region
 127 ;;;     (stealing some bytes from dynamic space) the problems went
 128 ;;;     away.
 129 ;;;   * The FreeBSD STATIC-SPACE-START value was bumped up from
 130 ;;;     #x28000000 to #x30000000 when FreeBSD ld.so dynamic linking
 131 ;;;     support was added for FreeBSD ca. 20000910. This was to keep from
 132 ;;;     stomping on an address range that the dynamic libraries want to
 133 ;;;     use. (They want to use this address range even if we try to
 134 ;;;     reserve it with a call to validate() as the first operation in
 135 ;;;     main().)
 136 ;;;   * For NetBSD 2.0, the following ranges are used by normal
 137 ;;;     executables and mmap:
 138 ;;;     ** Executables are (by default) loaded at 0x08048000.
 139 ;;;     ** The break for the sbcl runtime seems to end around 0x08400000
 140 ;;;     We set read only space around 0x20000000, static
 141 ;;;     space around 0x30000000, all ending below 0x37fff000
 142 ;;;     ** ld.so and other mmap'ed stuff like shared libs start around
 143 ;;;        0x48000000
 144 ;;;     We set dynamic space between 0x60000000 and 0x98000000
 145 ;;;     ** Bottom of the stack is typically not below 0xb0000000
 146 ;;;     FYI, this can be looked at with the "pmap" program, and if you
 147 ;;;     set the top-down mmap allocation option in the kernel (not yet
 148 ;;;     the default), all bets are totally off!
 149
 150 #!+linux
 151 (progn
 152   (def!constant read-only-space-start     #x01000000)
 153   (def!constant read-only-space-end       #x037ff000)
 154
 155   (def!constant static-space-start        #x05000000)
 156   (def!constant static-space-end          #x07fff000)
 157
 158   (def!constant dynamic-space-start       #x09000000)
 159   (def!constant dynamic-space-end         #x29000000)
 160
 161   (def!constant linkage-table-space-start #x70000000)
 162   (def!constant linkage-table-space-end   #x7ffff000))
 163
 164 #!+freebsd
 165 (progn
 166   (def!constant read-only-space-start     #x10000000)
 167   (def!constant read-only-space-end       #x1ffff000)
 168
 169   (def!constant static-space-start        #x30000000)
 170   (def!constant static-space-end          #x37fff000)
 171
 172   (def!constant dynamic-space-start       #x48000000)
 173   (def!constant dynamic-space-end         #x88000000)
 174
 175   ;; In CMUCL:  0xB0000000->0xB1000000
 176   (def!constant linkage-table-space-start #x90000000)
 177   (def!constant linkage-table-space-end   #x91000000))
 178
 179 #!+openbsd
 180 (progn
 181   (def!constant read-only-space-start     #x40000000)
 182   (def!constant read-only-space-end       #x47fff000)
 183
 184   (def!constant static-space-start        #x50000000)
 185   (def!constant static-space-end          #x5ffff000)
 186
 187   (def!constant dynamic-space-start       #x80000000)
 188   (def!constant dynamic-space-end         #xA0000000)
 189
 190   ;; In CMUCL: 0xB0000000->0xB1000000
 191   (def!constant linkage-table-space-start #xA0000000)
 192   (def!constant linkage-table-space-end   #xA1000000))
 193
 194 #!+netbsd
 195 (progn
 196   (def!constant read-only-space-start     #x20000000)
 197   (def!constant read-only-space-end       #x2ffff000)
 198
 199   (def!constant static-space-start        #x30000000)
 200   (def!constant static-space-end          #x37fff000)
 201
 202   (def!constant dynamic-space-start       #x60000000)
 203   (def!constant dynamic-space-end         #x98000000)
 204
 205   ;; In CMUCL: 0xB0000000->0xB1000000
 206   (def!constant linkage-table-space-start #xA0000000)
 207   (def!constant linkage-table-space-end   #xA1000000))
 208
 209 ;;; Size of one linkage-table entry in bytes.
 210 (def!constant linkage-table-entry-size 8)
 211
 212 ;;; Given that NIL is the first thing allocated in static space, we
 213 ;;; know its value at compile time:
 214 (def!constant nil-value (+ static-space-start #xb))
 215 \f
 216 ;;;; other miscellaneous constants
 217
 218 (defenum (:suffix -trap :start 8)
 219   halt
 220   pending-interrupt
 221   error
 222   cerror
 223   breakpoint
 224   fun-end-breakpoint
 225   single-step-breakpoint)
 226 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something like
 227 ;;;   (WITH-DEF-ENUM (:START 8)
 228 ;;;     (DEF-ENUM HALT-TRAP)
 229 ;;;     (DEF-ENUM PENDING-INTERRUPT-TRAP)
 230 ;;;     ..)
 231 ;;; for the benefit of anyone doing a lexical search for definitions
 232 ;;; of these symbols.
 233
 234 (defenum (:prefix object-not- :suffix -trap :start 16)
 235   list
 236   instance)
 237
 238 (defenum (:prefix trace-table-)
 239   normal
 240   call-site
 241   fun-prologue
 242   fun-epilogue)
 243 \f
 244 ;;;; static symbols
 245
 246 ;;; These symbols are loaded into static space directly after NIL so
 247 ;;; that the system can compute their address by adding a constant
 248 ;;; amount to NIL.
 249 ;;;
 250 ;;; The fdefn objects for the static functions are loaded into static
 251 ;;; space directly after the static symbols. That way, the raw-addr
 252 ;;; can be loaded directly out of them by indirecting relative to NIL.
 253 ;;;
 254 ;;; pfw X86 doesn't have enough registers to keep these things there.
 255 ;;;     Note these spaces grow from low to high addresses.
 256 (defvar *allocation-pointer*)
 257 (defvar *binding-stack-pointer*)
 258
 259 ;;; FIXME: !COLD-INIT probably doesn't need
 260 ;;; to be in the static symbols table any more.
 261 (defparameter *static-symbols*
 262   '(t
 263
 264     ;; The C startup code must fill these in.
 265     *posix-argv*
 266
 267     ;; functions that the C code needs to call.  When adding to this list,
 268     ;; also add a `frob' form in genesis.lisp finish-symbols.
 269     sub-gc
 270     sb!kernel::internal-error
 271     sb!kernel::control-stack-exhausted-error
 272     sb!kernel::undefined-alien-variable-error
 273     sb!kernel::undefined-alien-function-error
 274     sb!kernel::memory-fault-error
 275     sb!di::handle-breakpoint
 276     fdefinition-object
 277     #!+sb-thread sb!thread::handle-thread-exit
 278
 279     ;; free pointers
 280     ;;
 281     ;; Note that these are FIXNUM word counts, not (as one might
 282     ;; expect) byte counts or SAPs. The reason seems to be that by
 283     ;; representing them this way, we can avoid consing bignums.
 284     ;; -- WHN 2000-10-02
 285     *read-only-space-free-pointer*
 286     *static-space-free-pointer*
 287     *initial-dynamic-space-free-pointer*
 288
 289     ;; things needed for non-local exit
 290     *current-catch-block*
 291     *current-unwind-protect-block*
 292     *alien-stack*
 293
 294     ;; interrupt handling
 295     *pseudo-atomic-atomic*
 296     *pseudo-atomic-interrupted*
 297     sb!unix::*interrupts-enabled*
 298     sb!unix::*interrupt-pending*
 299     *free-interrupt-context-index*
 300
 301     *free-tls-index*
 302
 303     *allocation-pointer*
 304     *binding-stack-pointer*
 305     *binding-stack-start*
 306     *control-stack-start*
 307     *control-stack-end*
 308
 309     *need-to-collect-garbage*
 310
 311     ;; the floating point constants
 312     *fp-constant-0d0*
 313     *fp-constant-1d0*
 314     *fp-constant-0f0*
 315     *fp-constant-1f0*
 316     ;; The following are all long-floats.
 317     *fp-constant-0l0*
 318     *fp-constant-1l0*
 319     *fp-constant-pi*
 320     *fp-constant-l2t*
 321     *fp-constant-l2e*
 322     *fp-constant-lg2*
 323     *fp-constant-ln2*
 324
 325     ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
 326     ;; common slot unbound check.
 327     ;;
 328     ;; FIXME: In SBCL, the CLOS code has become sufficiently tightly
 329     ;; integrated into the system that it'd probably make sense to use
 330     ;; the ordinary unbound marker for this.
 331     sb!pcl::..slot-unbound..
 332     ))
 333
 334 (defparameter *static-funs*
 335   '(length
 336     sb!kernel:two-arg-+
 337     sb!kernel:two-arg--
 338     sb!kernel:two-arg-*
 339     sb!kernel:two-arg-/
 340     sb!kernel:two-arg-<
 341     sb!kernel:two-arg->
 342     sb!kernel:two-arg-=
 343     eql
 344     sb!kernel:%negate
 345     sb!kernel:two-arg-and
 346     sb!kernel:two-arg-ior
 347     sb!kernel:two-arg-xor
 348     sb!kernel:two-arg-gcd
 349     sb!kernel:two-arg-lcm))
 350 \f
 351 ;;;; stuff added by jrd
 352
 353 ;;; FIXME: Is this used? Delete it or document it.
 354 ;;; cf the sparc PARMS.LISP
 355 (defparameter *assembly-unit-length* 8)