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.
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.
25 ;;;; machine architecture parameters
27 ;;; the number of bits per word, where a word holds one lisp descriptor
28 (def!constant n-word-bits 64)
30 ;;; the natural width of a machine word (as seen in e.g. register width,
32 (def!constant n-machine-word-bits 64)
34 ;;; the number of bits per byte, where a byte is the smallest
35 ;;; addressable object
36 (def!constant n-byte-bits 8)
38 (def!constant float-sign-shift 31)
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))
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))
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))
71 (def!constant single-float-digits
72 (+ (byte-size single-float-significand-byte) 1))
74 (def!constant double-float-digits
75 (+ (byte-size double-float-significand-byte) 32 1))
77 (def!constant long-float-digits
78 (+ (byte-size long-float-significand-byte) 32 1))
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))
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)
93 (defconstant-eqx float-rounding-mode (byte 2 10) #'equalp)
94 (defconstant-eqx float-sticky-bits (byte 6 16) #'equalp)
95 (defconstant-eqx float-traps-byte (byte 6 0) #'equalp)
96 (defconstant-eqx float-exceptions-byte (byte 6 16) #'equalp)
97 (defconstant-eqx float-precision-control (byte 2 8) #'equalp)
98 (def!constant float-fast-bit 0) ; no fast mode on x86
100 ;;;; description of the target address space
102 ;;; where to put the different spaces. untested (copied from x86, in fact)
105 (def!constant read-only-space-start #x01000000)
106 (def!constant read-only-space-end #x037ff000)
108 (def!constant static-space-start #x05000000)
109 (def!constant static-space-end #x07fff000)
111 (def!constant dynamic-space-start #x09000000)
112 (def!constant dynamic-space-end #x29000000)
115 ;;;; other miscellaneous constants
117 (defenum (:suffix -trap :start 8)
124 single-step-breakpoint)
125 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something like
126 ;;; (WITH-DEF-ENUM (:START 8)
127 ;;; (DEF-ENUM HALT-TRAP)
128 ;;; (DEF-ENUM PENDING-INTERRUPT-TRAP)
130 ;;; for the benefit of anyone doing a lexical search for definitions
131 ;;; of these symbols.
133 (defenum (:prefix object-not- :suffix -trap :start 16)
137 (defenum (:prefix trace-table-)
145 ;;; These symbols are loaded into static space directly after NIL so
146 ;;; that the system can compute their address by adding a constant
149 ;;; The fdefn objects for the static functions are loaded into static
150 ;;; space directly after the static symbols. That way, the raw-addr
151 ;;; can be loaded directly out of them by indirecting relative to NIL.
153 ;;; we could profitably keep these in registers on x86-64 now we have
155 ;;; Note these spaces grow from low to high addresses.
156 (defvar *allocation-pointer*)
157 (defvar *binding-stack-pointer*)
159 ;;; FIXME: !COLD-INIT probably doesn't need
160 ;;; to be in the static symbols table any more.
161 (defparameter *static-symbols*
164 ;; The C startup code must fill these in.
167 ;; functions that the C code needs to call. When adding to this list,
168 ;; also add a `frob' form in genesis.lisp finish-symbols.
170 sb!kernel::internal-error
171 sb!kernel::control-stack-exhausted-error
172 sb!di::handle-breakpoint
174 #!+sb-thread sb!thread::handle-thread-exit
178 ;; Note that these are FIXNUM word counts, not (as one might
179 ;; expect) byte counts or SAPs. The reason seems to be that by
180 ;; representing them this way, we can avoid consing bignums.
182 *read-only-space-free-pointer*
183 *static-space-free-pointer*
184 *initial-dynamic-space-free-pointer*
186 ;; things needed for non-local exit
187 *current-catch-block*
188 *current-unwind-protect-block*
191 ;; interrupt handling
192 *pseudo-atomic-atomic*
193 *pseudo-atomic-interrupted*
194 sb!unix::*interrupts-enabled*
195 sb!unix::*interrupt-pending*
196 *free-interrupt-context-index*
201 *binding-stack-pointer*
202 *binding-stack-start*
203 *control-stack-start*
206 ;; the floating point constants
211 ;; The following are all long-floats.
220 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
221 ;; common slot unbound check.
223 ;; FIXME: In SBCL, the CLOS code has become sufficiently tightly
224 ;; integrated into the system that it'd probably make sense to use
225 ;; the ordinary unbound marker for this.
226 sb!pcl::..slot-unbound..))
228 (defparameter *static-funs*
239 sb!kernel:two-arg-and
240 sb!kernel:two-arg-ior
241 sb!kernel:two-arg-xor
242 sb!kernel:two-arg-gcd
243 sb!kernel:two-arg-lcm))
245 ;;;; stuff added by jrd
247 ;;; FIXME: Is this used? Delete it or document it.
248 ;;; cf the sparc PARMS.LISP
249 (defparameter *assembly-unit-length* 8)