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.
5 ;;;; This software is part of the SBCL system. See the README file for
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.
19 ;;; ### Note: we simultaneously use ``word'' to mean a 32 bit quantity
20 ;;; and a 16 bit quantity depending on context. This is because Intel
21 ;;; insists on calling 16 bit things words and 32 bit things
22 ;;; double-words (or dwords). Therefore, in the instruction definition
23 ;;; and register specs, we use the Intel convention. But whenever we
24 ;;; are talking about stuff the rest of the lisp system might be
25 ;;; interested in, we use ``word'' to mean the size of a descriptor
26 ;;; object, which is 32 bits.
28 ;;;; machine architecture parameters
30 (eval-when (:compile-toplevel :load-toplevel :execute)
32 (defconstant word-bits 32
34 "Number of bits per word where a word holds one lisp descriptor.")
36 (defconstant byte-bits 8
38 "Number of bits per byte where a byte is the smallest addressable object.")
40 (defconstant word-shift (1- (integer-length (/ word-bits byte-bits)))
42 "Number of bits to shift between word addresses and byte addresses.")
44 (defconstant word-bytes (/ word-bits byte-bits)
46 "Number of bytes in a word.")
50 (eval-when (:compile-toplevel :load-toplevel :execute)
51 (defconstant float-sign-shift 31)
53 ;; These values were taken from the alpha code. The values for
54 ;; bias and exponent min/max are not the same as shown in the 486 book.
55 ;; They may be correct for how Python uses them.
56 (defconstant single-float-bias 126) ; Intel says 127
57 (defconstant single-float-exponent-byte (byte 8 23))
58 (defconstant single-float-significand-byte (byte 23 0))
59 ;; The 486 book shows the exponent range -126 to +127. The Lisp
60 ;; code that uses these values seems to want already biased numbers.
61 (defconstant single-float-normal-exponent-min 1)
62 (defconstant single-float-normal-exponent-max 254)
63 (defconstant single-float-hidden-bit (ash 1 23))
64 (defconstant single-float-trapping-nan-bit (ash 1 22))
66 (defconstant double-float-bias 1022)
67 (defconstant double-float-exponent-byte (byte 11 20))
68 (defconstant double-float-significand-byte (byte 20 0))
69 (defconstant double-float-normal-exponent-min 1)
70 (defconstant double-float-normal-exponent-max #x7FE)
71 (defconstant double-float-hidden-bit (ash 1 20))
72 (defconstant double-float-trapping-nan-bit (ash 1 19))
74 (defconstant long-float-bias 16382)
75 (defconstant long-float-exponent-byte (byte 15 0))
76 (defconstant long-float-significand-byte (byte 31 0))
77 (defconstant long-float-normal-exponent-min 1)
78 (defconstant long-float-normal-exponent-max #x7FFE)
79 (defconstant long-float-hidden-bit (ash 1 31)) ; Actually not hidden
80 (defconstant long-float-trapping-nan-bit (ash 1 30))
82 (defconstant single-float-digits
83 (+ (byte-size single-float-significand-byte) 1))
85 (defconstant double-float-digits
86 (+ (byte-size double-float-significand-byte) word-bits 1))
88 (defconstant long-float-digits
89 (+ (byte-size long-float-significand-byte) word-bits 1))
91 ;;; pfw -- from i486 microprocessor programmers reference manual
92 (defconstant float-invalid-trap-bit (ash 1 0))
93 (defconstant float-denormal-trap-bit (ash 1 1))
94 (defconstant float-divide-by-zero-trap-bit (ash 1 2))
95 (defconstant float-overflow-trap-bit (ash 1 3))
96 (defconstant float-underflow-trap-bit (ash 1 4))
97 (defconstant float-inexact-trap-bit (ash 1 5))
99 (defconstant float-round-to-nearest 0)
100 (defconstant float-round-to-negative 1)
101 (defconstant float-round-to-positive 2)
102 (defconstant float-round-to-zero 3)
104 (defconstant float-rounding-mode (byte 2 10))
105 (defconstant float-sticky-bits (byte 6 16))
106 (defconstant float-traps-byte (byte 6 0))
107 (defconstant float-exceptions-byte (byte 6 16))
108 (defconstant float-precision-control (byte 2 8))
109 (defconstant float-fast-bit 0) ; No fast mode on x86
113 ;;;; description of the target address space
115 ;;; where to put the different spaces
117 ;;; FIXME: Couldn't/shouldn't these be DEFCONSTANT instead of DEFPARAMETER?
119 ;;; FIXME: Since SBCL has a different way of distinguishing between target
120 ;;; and host than the old CMU CL code used, the "TARGET-" prefix is
121 ;;; redundant. Perhaps each *TARGET-FOO* should become *FOO*, probably
122 ;;; at the same time that we unscrew the kludgy way that constants are
123 ;;; duplicated between this file and runtime/x86-validate.h.
125 ;;; Note: Mostly these values are black magic, inherited from CMU CL
126 ;;; without any documentation. However, there have been a few changes
128 ;;; * The FreeBSD STATIC-SPACE-START value was bumped up
129 ;;; from #x28000000 to #x30000000 when FreeBSD ld.so dynamic linking
130 ;;; support was added for FreeBSD ca. 20000910. This was to keep from
131 ;;; stomping on an address range that the dynamic libraries want to use.
132 ;;; (They want to use this address range even if we try to reserve it
133 ;;; with a call to validate() as the first operation in main().)
136 (defconstant read-only-space-start #x01000000)
137 (defconstant static-space-start #x05000000)
138 (defparameter *dynamic-space-start* #x09000000))
141 (defconstant read-only-space-start #x10000000)
142 (defconstant static-space-start
143 #!+freebsd #x30000000
144 #!+openbsd #x28000000)
145 (defparameter *dynamic-space-start* #x48000000))
147 ;;; Given that NIL is the first thing allocated in static space, we
148 ;;; know its value at compile time:
149 (defconstant nil-value (+ static-space-start #xb))
151 ;;;; other miscellaneous constants
153 (defenum (:suffix -trap :start 8)
159 function-end-breakpoint
160 single-step-breakpoint)
161 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something
163 ;;; (WITH-DEF-ENUM (:START 8)
164 ;;; (DEF-ENUM HALT-TRAP)
165 ;;; (DEF-ENUM PENDING-INTERRUPT-TRAP)
167 ;;; for the benefit of anyone doing a lexical search for definitions
168 ;;; of these symbols.
170 (defenum (:prefix object-not- :suffix -trap :start 16)
174 (defenum (:prefix trace-table-)
182 ;;; These symbols are loaded into static space directly after NIL so
183 ;;; that the system can compute their address by adding a constant
186 ;;; The fdefn objects for the static functions are loaded into static
187 ;;; space directly after the static symbols. That way, the raw-addr
188 ;;; can be loaded directly out of them by indirecting relative to NIL.
190 ;;; pfw X86 doesn't have enough registers to keep these things there.
191 ;;; Note these spaces grow from low to high addresses.
192 (defvar *allocation-pointer*)
193 (defvar *binding-stack-pointer*)
194 (defvar *x86-cgc-active-p*) ; FIXME: Document this.
195 (defvar *static-blue-bag* nil)
197 ;;; FIXME: *!INITIAL-FDEFN-OBJECTS* and !COLD-INIT probably don't need
198 ;;; to be in the static symbols table any more. Also, if
199 ;;; *INTERNAL-GC-TRIGGER* really is not used, we can punt it.
200 (defparameter *static-symbols*
203 ;; The C startup code must fill these in.
205 sb!impl::*!initial-fdefn-objects*
207 ;; functions that the C code needs to call
210 sb!kernel::internal-error
211 sb!di::handle-breakpoint
212 sb!impl::fdefinition-object
216 ;; Note that these are FIXNUM word counts, not (as one might
217 ;; expect) byte counts or SAPs. The reason seems to be that by
218 ;; representing them this way, we can avoid consing bignums.
220 *read-only-space-free-pointer*
221 *static-space-free-pointer*
222 *initial-dynamic-space-free-pointer*
224 ;; things needed for non-local exit
225 sb!impl::*current-catch-block*
226 sb!impl::*current-unwind-protect-block*
227 sb!c::*eval-stack-top*
230 ;; interrupt handling
231 sb!impl::*pseudo-atomic-atomic*
232 sb!impl::*pseudo-atomic-interrupted*
233 sb!unix::*interrupts-enabled*
234 sb!unix::*interrupt-pending*
235 sb!impl::*free-interrupt-context-index*
237 sb!vm::*allocation-pointer*
238 sb!vm::*binding-stack-pointer*
239 sb!vm::*internal-gc-trigger* ; Not used.
241 ;; the floating point constants
242 sb!vm::*fp-constant-0d0*
243 sb!vm::*fp-constant-1d0*
244 sb!vm::*fp-constant-0s0*
245 sb!vm::*fp-constant-1s0*
246 ;; The following are all long-floats.
247 sb!vm::*fp-constant-0l0*
248 sb!vm::*fp-constant-1l0*
249 sb!vm::*fp-constant-pi*
250 sb!vm::*fp-constant-l2t*
251 sb!vm::*fp-constant-l2e*
252 sb!vm::*fp-constant-lg2*
253 sb!vm::*fp-constant-ln2*
256 sb!vm::*scavenge-read-only-space*
258 ;; multi-process support
259 sb!vm::*control-stacks*
261 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
262 ;; common slot unbound check.
263 sb!pcl::..slot-unbound..
278 sb!vm::*x86-cgc-active-p*
279 sb!vm::*static-blue-bag* ; must be last or change C code
282 (defparameter *static-functions*
293 sb!kernel:two-arg-and
294 sb!kernel:two-arg-ior
295 sb!kernel:two-arg-xor
296 sb!kernel:two-arg-gcd
297 sb!kernel:two-arg-lcm))
299 ;;;; stuff added by jrd
301 ;;; FIXME: Is this used? Delete it or document it.
302 ;;; cf the sparc PARMS.LISP
303 (defparameter *assembly-unit-length* 8)