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?
118 #!-linux (defparameter *target-read-only-space-start* #x10000000)
119 #!-linux (defparameter *target-static-space-start* #x28000000)
120 #!-linux (defparameter *target-dynamic-space-start* #x48000000)
121 #!+linux (defparameter *target-read-only-space-start* #x01000000)
122 #!+linux (defparameter *target-static-space-start* #x05000000)
123 #!+linux (defparameter *target-dynamic-space-start* #x09000000)
125 ;;; Given that NIL is the first things allocated in static space, we
126 ;;; know its value at compile time:
128 ;;; FIXME: Couldn't/shouldn't this be a DEFCONSTANT, and shouldn't it be
129 ;;; calculated from TARGET-STATIC-SPACE-START instead of assigned
131 #!-linux (defparameter *nil-value* #x2800000B)
132 #!+linux (defparameter *nil-value* #x0500000B)
134 ;;;; other miscellaneous constants
136 (defenum (:suffix -trap :start 8)
142 function-end-breakpoint
143 single-step-breakpoint)
144 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something
146 ;;; (WITH-DEF-ENUM (:START 8)
147 ;;; (DEF-ENUM HALT-TRAP)
148 ;;; (DEF-ENUM PENDING-INTERRUPT-TRAP)
150 ;;; for the benefit of anyone doing a lexical search for definitions
151 ;;; of these symbols.
153 (defenum (:prefix object-not- :suffix -trap :start 16)
157 (defenum (:prefix trace-table-)
165 ;;; These symbols are loaded into static space directly after NIL so
166 ;;; that the system can compute their address by adding a constant
169 ;;; The fdefn objects for the static functions are loaded into static
170 ;;; space directly after the static symbols. That way, the raw-addr
171 ;;; can be loaded directly out of them by indirecting relative to NIL.
173 ;;; pfw X86 doesn't have enough registers to keep these things there.
174 ;;; Note these spaces grow from low to high addresses.
175 (defvar *allocation-pointer*)
176 (defvar *binding-stack-pointer*)
177 (defvar *x86-cgc-active-p*) ; FIXME: Document this.
178 (defvar *static-blue-bag* nil)
180 ;;; FIXME: *!INITIAL-FDEFN-OBJECTS* and !COLD-INIT probably don't need
181 ;;; to be in the static symbols table any more. Also, if
182 ;;; *INTERNAL-GC-TRIGGER* really is not used, we can punt it.
183 (defparameter *static-symbols*
186 ;; The C startup code must fill these in.
188 sb!impl::*!initial-fdefn-objects*
190 ;; functions that the C code needs to call
193 sb!kernel::internal-error
194 sb!di::handle-breakpoint
195 sb!impl::fdefinition-object
198 sb!impl::*read-only-space-free-pointer*
199 sb!impl::*static-space-free-pointer*
200 sb!impl::*initial-dynamic-space-free-pointer*
202 ;; things needed for non-local exit
203 sb!impl::*current-catch-block*
204 sb!impl::*current-unwind-protect-block*
205 sb!c::*eval-stack-top*
208 ;; interrupt handling
209 sb!impl::*pseudo-atomic-atomic*
210 sb!impl::*pseudo-atomic-interrupted*
211 sb!unix::*interrupts-enabled*
212 sb!unix::*interrupt-pending*
213 sb!impl::*free-interrupt-context-index*
215 sb!vm::*allocation-pointer*
216 sb!vm::*binding-stack-pointer*
217 sb!vm::*internal-gc-trigger* ; Not used.
219 ;; the floating point constants
220 sb!vm::*fp-constant-0d0*
221 sb!vm::*fp-constant-1d0*
222 sb!vm::*fp-constant-0s0*
223 sb!vm::*fp-constant-1s0*
224 ;; The following are all long-floats.
225 sb!vm::*fp-constant-0l0*
226 sb!vm::*fp-constant-1l0*
227 sb!vm::*fp-constant-pi*
228 sb!vm::*fp-constant-l2t*
229 sb!vm::*fp-constant-l2e*
230 sb!vm::*fp-constant-lg2*
231 sb!vm::*fp-constant-ln2*
234 sb!vm::*scavenge-read-only-space*
236 ;; multi-process support
237 sb!vm::*control-stacks*
239 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
240 ;; common slot unbound check.
241 sb!pcl::..slot-unbound..
256 sb!vm::*x86-cgc-active-p*
257 sb!vm::*static-blue-bag* ; must be last or change C code
260 (defparameter *static-functions*
271 sb!kernel:two-arg-and
272 sb!kernel:two-arg-ior
273 sb!kernel:two-arg-xor
274 sb!kernel:two-arg-gcd
275 sb!kernel:two-arg-lcm))
277 ;;;; stuff added by jrd
279 ;;; FIXME: Is this used? Delete it or document it.
280 ;;; cf the sparc PARMS.LISP
281 (defparameter *assembly-unit-length* 8)