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 single-float-digits
64 (+ (byte-size single-float-significand-byte) 1))
66 (def!constant double-float-digits
67 (+ (byte-size double-float-significand-byte) 32 1))
69 ;;; from AMD64 Architecture manual
70 (def!constant float-invalid-trap-bit (ash 1 0))
71 (def!constant float-denormal-trap-bit (ash 1 1))
72 (def!constant float-divide-by-zero-trap-bit (ash 1 2))
73 (def!constant float-overflow-trap-bit (ash 1 3))
74 (def!constant float-underflow-trap-bit (ash 1 4))
75 (def!constant float-inexact-trap-bit (ash 1 5))
77 (def!constant float-round-to-nearest 0)
78 (def!constant float-round-to-negative 1)
79 (def!constant float-round-to-positive 2)
80 (def!constant float-round-to-zero 3)
82 (defconstant-eqx float-rounding-mode (byte 2 13) #'equalp)
83 (defconstant-eqx float-sticky-bits (byte 6 0) #'equalp)
84 (defconstant-eqx float-traps-byte (byte 6 7) #'equalp)
85 (defconstant-eqx float-exceptions-byte (byte 6 0) #'equalp)
86 (def!constant float-fast-bit 0) ; no fast mode on x86-64
88 ;;;; description of the target address space
90 ;;; where to put the different spaces.
92 ;;; Currently the read-only and static spaces must be located in low
93 ;;; memory (certainly under the 4GB limit, very probably under 2GB
94 ;;; limit). This is due to the inability of using immediate values of
95 ;;; more than 32 bits (31 bits if you take sign extension into
96 ;;; account) in any other instructions except MOV. Removing this limit
97 ;;; would be possible, but probably not worth the time and code bloat
98 ;;; it would cause. -- JES, 2005-12-11
100 #!+(or linux freebsd)
102 (def!constant read-only-space-start #x20000000)
103 (def!constant read-only-space-end #x27ff0000)
105 (def!constant static-space-start #x40000000)
106 (def!constant static-space-end #x47fff000)
108 (def!constant dynamic-space-start #x1000000000)
109 (def!constant dynamic-space-end #x11ffff0000)
111 (def!constant linkage-table-space-start #x60000000)
112 (def!constant linkage-table-space-end #x63fff000)
114 (def!constant linkage-table-entry-size 16))
118 (def!constant read-only-space-start #x20000000)
119 (def!constant read-only-space-end #x27ff0000)
121 (def!constant static-space-start #x40000000)
122 (def!constant static-space-end #x47fff000)
124 #+nil (def!constant dynamic-space-start #x1000000000)
125 #+nil (def!constant dynamic-space-end #x11ffff0000)
127 (def!constant dynamic-space-start #x50000000)
128 (def!constant dynamic-space-end #x5fff0000)
130 (def!constant linkage-table-space-start #x60000000)
131 (def!constant linkage-table-space-end #x63fff000)
133 (def!constant linkage-table-entry-size 16))
137 ;;;; other miscellaneous constants
139 (defenum (:suffix -trap :start 8)
148 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something like
149 ;;; (WITH-DEF-ENUM (:START 8)
150 ;;; (DEF-ENUM HALT-TRAP)
151 ;;; (DEF-ENUM PENDING-INTERRUPT-TRAP)
153 ;;; for the benefit of anyone doing a lexical search for definitions
154 ;;; of these symbols.
156 (defenum (:prefix object-not- :suffix -trap :start 24)
160 (defenum (:prefix trace-table-)
168 ;;; These symbols are loaded into static space directly after NIL so
169 ;;; that the system can compute their address by adding a constant
172 ;;; The fdefn objects for the static functions are loaded into static
173 ;;; space directly after the static symbols. That way, the raw-addr
174 ;;; can be loaded directly out of them by indirecting relative to NIL.
176 ;;; we could profitably keep these in registers on x86-64 now we have
178 ;;; Note these spaces grow from low to high addresses.
179 (defvar *allocation-pointer*)
180 (defvar *binding-stack-pointer*)
182 (defparameter *static-symbols*
184 *common-static-symbols*
185 *c-callable-static-symbols*
188 ;; interrupt handling
191 #!+sb-thread *stop-for-gc-pending*
193 #!+sb-thread *free-tls-index*
194 #!+sb-thread *tls-index-lock*
197 *binding-stack-pointer*
199 ;; the floating point constants
206 *restart-lisp-function*
208 ;; Needed for callbacks to work across saving cores. see
209 ;; ALIEN-CALLBACK-ASSEMBLER-WRAPPER in c-call.lisp for gory
211 sb!alien::*enter-alien-callback*
213 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
214 ;; common slot unbound check.
216 ;; FIXME: In SBCL, the CLOS code has become sufficiently tightly
217 ;; integrated into the system that it'd probably make sense to
218 ;; use the ordinary unbound marker for this.
220 ;; FIXME II: if it doesn't make sense, why is this X86-ish only?
221 sb!pcl::..slot-unbound..)))
223 (defparameter *static-funs*
234 sb!kernel:two-arg-and
235 sb!kernel:two-arg-ior
236 sb!kernel:two-arg-xor
237 sb!kernel:two-arg-gcd
238 sb!kernel:two-arg-lcm))