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 ;;; The size in bytes of the GENCGC pages. Should be a multiple of the
39 ;;; architecture code size.
40 (def!constant gencgc-page-size 4096)
42 (def!constant float-sign-shift 31)
44 ;;; comment from CMU CL:
45 ;;; These values were taken from the alpha code. The values for
46 ;;; bias and exponent min/max are not the same as shown in the 486 book.
47 ;;; They may be correct for how Python uses them.
48 (def!constant single-float-bias 126) ; Intel says 127.
49 (defconstant-eqx single-float-exponent-byte (byte 8 23) #'equalp)
50 (defconstant-eqx single-float-significand-byte (byte 23 0) #'equalp)
51 ;;; comment from CMU CL:
52 ;;; The 486 book shows the exponent range -126 to +127. The Lisp
53 ;;; code that uses these values seems to want already biased numbers.
54 (def!constant single-float-normal-exponent-min 1)
55 (def!constant single-float-normal-exponent-max 254)
56 (def!constant single-float-hidden-bit (ash 1 23))
57 (def!constant single-float-trapping-nan-bit (ash 1 22))
59 (def!constant double-float-bias 1022)
60 (defconstant-eqx double-float-exponent-byte (byte 11 20) #'equalp)
61 (defconstant-eqx double-float-significand-byte (byte 20 0) #'equalp)
62 (def!constant double-float-normal-exponent-min 1)
63 (def!constant double-float-normal-exponent-max #x7FE)
64 (def!constant double-float-hidden-bit (ash 1 20))
65 (def!constant double-float-trapping-nan-bit (ash 1 19))
67 (def!constant single-float-digits
68 (+ (byte-size single-float-significand-byte) 1))
70 (def!constant double-float-digits
71 (+ (byte-size double-float-significand-byte) 32 1))
73 ;;; from AMD64 Architecture manual
74 (def!constant float-invalid-trap-bit (ash 1 0))
75 (def!constant float-denormal-trap-bit (ash 1 1))
76 (def!constant float-divide-by-zero-trap-bit (ash 1 2))
77 (def!constant float-overflow-trap-bit (ash 1 3))
78 (def!constant float-underflow-trap-bit (ash 1 4))
79 (def!constant float-inexact-trap-bit (ash 1 5))
81 (def!constant float-round-to-nearest 0)
82 (def!constant float-round-to-negative 1)
83 (def!constant float-round-to-positive 2)
84 (def!constant float-round-to-zero 3)
86 (defconstant-eqx float-rounding-mode (byte 2 13) #'equalp)
87 (defconstant-eqx float-sticky-bits (byte 6 0) #'equalp)
88 (defconstant-eqx float-traps-byte (byte 6 7) #'equalp)
89 (defconstant-eqx float-exceptions-byte (byte 6 0) #'equalp)
90 (def!constant float-fast-bit 0) ; no fast mode on x86-64
92 ;;;; description of the target address space
94 ;;; where to put the different spaces.
96 ;;; Currently the read-only and static spaces must be located in low
97 ;;; memory (certainly under the 4GB limit, very probably under 2GB
98 ;;; limit). This is due to the inability of using immediate values of
99 ;;; more than 32 bits (31 bits if you take sign extension into
100 ;;; account) in any other instructions except MOV. Removing this limit
101 ;;; would be possible, but probably not worth the time and code bloat
102 ;;; it would cause. -- JES, 2005-12-11
104 (def!constant read-only-space-start #x20000000)
105 (def!constant read-only-space-end #x27ff0000)
107 (def!constant static-space-start #x40000000)
108 (def!constant static-space-end #x47fff000)
110 (def!constant dynamic-space-start #x1000000000)
111 (def!constant dynamic-space-end #x11ffff0000)
113 (def!constant linkage-table-space-start #x60000000)
114 (def!constant linkage-table-space-end #x63fff000)
116 (def!constant linkage-table-entry-size 16)
118 ;;;; other miscellaneous constants
120 (defenum (:suffix -trap :start 8)
129 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something like
130 ;;; (WITH-DEF-ENUM (:START 8)
131 ;;; (DEF-ENUM HALT-TRAP)
132 ;;; (DEF-ENUM PENDING-INTERRUPT-TRAP)
134 ;;; for the benefit of anyone doing a lexical search for definitions
135 ;;; of these symbols.
137 (defenum (:prefix object-not- :suffix -trap :start 24)
141 (defenum (:prefix trace-table-)
149 ;;; These symbols are loaded into static space directly after NIL so
150 ;;; that the system can compute their address by adding a constant
153 ;;; The fdefn objects for the static functions are loaded into static
154 ;;; space directly after the static symbols. That way, the raw-addr
155 ;;; can be loaded directly out of them by indirecting relative to NIL.
157 ;;; we could profitably keep these in registers on x86-64 now we have
159 ;;; Note these spaces grow from low to high addresses.
160 (defvar *allocation-pointer*)
161 (defvar *binding-stack-pointer*)
163 (defparameter *static-symbols*
165 *common-static-symbols*
166 *c-callable-static-symbols*
169 ;; interrupt handling
172 #!+sb-thread *stop-for-gc-pending*
174 #!+sb-thread *free-tls-index*
175 #!+sb-thread *tls-index-lock*
178 *binding-stack-pointer*
180 ;; the floating point constants
187 *restart-lisp-function*
189 ;; Needed for callbacks to work across saving cores. see
190 ;; ALIEN-CALLBACK-ASSEMBLER-WRAPPER in c-call.lisp for gory
192 sb!alien::*enter-alien-callback*
194 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
195 ;; common slot unbound check.
197 ;; FIXME: In SBCL, the CLOS code has become sufficiently tightly
198 ;; integrated into the system that it'd probably make sense to
199 ;; use the ordinary unbound marker for this.
201 ;; FIXME II: if it doesn't make sense, why is this X86-ish only?
202 sb!pcl::..slot-unbound..)))
204 (defparameter *static-funs*
215 sb!kernel:two-arg-and
216 sb!kernel:two-arg-ior
217 sb!kernel:two-arg-xor
218 sb!kernel:two-arg-gcd
219 sb!kernel:two-arg-lcm))