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 32)
30 ;;; the natural width of a machine word (as seen in e.g. register width,
32 (def!constant n-machine-word-bits 32)
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 minimum immediate offset in a memory-referencing instruction.
39 (def!constant minimum-immediate-offset (- (expt 2 31)))
41 ;;; The maximum immediate offset in a memory-referencing instruction.
42 (def!constant maximum-immediate-offset (1- (expt 2 31)))
44 (def!constant float-sign-shift 31)
46 ;;; comment from CMU CL:
47 ;;; These values were taken from the alpha code. The values for
48 ;;; bias and exponent min/max are not the same as shown in the 486 book.
49 ;;; They may be correct for how Python uses them.
50 (def!constant single-float-bias 126) ; Intel says 127.
51 (defconstant-eqx single-float-exponent-byte (byte 8 23) #'equalp)
52 (defconstant-eqx single-float-significand-byte (byte 23 0) #'equalp)
53 ;;; comment from CMU CL:
54 ;;; The 486 book shows the exponent range -126 to +127. The Lisp
55 ;;; code that uses these values seems to want already biased numbers.
56 (def!constant single-float-normal-exponent-min 1)
57 (def!constant single-float-normal-exponent-max 254)
58 (def!constant single-float-hidden-bit (ash 1 23))
59 (def!constant single-float-trapping-nan-bit (ash 1 22))
61 (def!constant double-float-bias 1022)
62 (defconstant-eqx double-float-exponent-byte (byte 11 20) #'equalp)
63 (defconstant-eqx double-float-significand-byte (byte 20 0) #'equalp)
64 (def!constant double-float-normal-exponent-min 1)
65 (def!constant double-float-normal-exponent-max #x7FE)
66 (def!constant double-float-hidden-bit (ash 1 20))
67 (def!constant double-float-trapping-nan-bit (ash 1 19))
69 (def!constant long-float-bias 16382)
70 (defconstant-eqx long-float-exponent-byte (byte 15 0) #'equalp)
71 (defconstant-eqx long-float-significand-byte (byte 31 0) #'equalp)
72 (def!constant long-float-normal-exponent-min 1)
73 (def!constant long-float-normal-exponent-max #x7FFE)
74 (def!constant long-float-hidden-bit (ash 1 31)) ; actually not hidden
75 (def!constant long-float-trapping-nan-bit (ash 1 30))
77 (def!constant single-float-digits
78 (+ (byte-size single-float-significand-byte) 1))
80 (def!constant double-float-digits
81 (+ (byte-size double-float-significand-byte) n-word-bits 1))
83 (def!constant long-float-digits
84 (+ (byte-size long-float-significand-byte) n-word-bits 1))
86 ;;; pfw -- from i486 microprocessor programmer's reference manual
87 (def!constant float-invalid-trap-bit (ash 1 0))
88 (def!constant float-denormal-trap-bit (ash 1 1))
89 (def!constant float-divide-by-zero-trap-bit (ash 1 2))
90 (def!constant float-overflow-trap-bit (ash 1 3))
91 (def!constant float-underflow-trap-bit (ash 1 4))
92 (def!constant float-inexact-trap-bit (ash 1 5))
94 (def!constant float-round-to-nearest 0)
95 (def!constant float-round-to-negative 1)
96 (def!constant float-round-to-positive 2)
97 (def!constant float-round-to-zero 3)
99 (def!constant float-precision-24-bit 0)
100 (def!constant float-precision-53-bit 2)
101 (def!constant float-precision-64-bit 3)
103 (defconstant-eqx float-rounding-mode (byte 2 10) #'equalp)
104 (defconstant-eqx float-sticky-bits (byte 6 16) #'equalp)
105 (defconstant-eqx float-traps-byte (byte 6 0) #'equalp)
106 (defconstant-eqx float-exceptions-byte (byte 6 16) #'equalp)
107 (defconstant-eqx float-precision-control (byte 2 8) #'equalp)
108 (def!constant float-fast-bit 0) ; no fast mode on x86
110 ;;;; description of the target address space
112 ;;; where to put the different spaces
114 ;;; Note: Mostly these values are black magic, inherited from CMU CL
115 ;;; without any documentation. However, there were a few explanatory
116 ;;; comments in the CMU CL sources:
118 ;;; ** The space 0x08000000-0x10000000 is "C program and memory allocation".
119 ;;; ** The space 0x40000000-0x48000000 is reserved for shared libs.
120 ;;; ** The space >0xE0000000 is "C stack - Alien stack".
122 ;;; ** The space 0x0E000000-0x10000000 is "Foreign segment".
123 ;;; ** The space 0x20000000-0x30000000 is reserved for shared libs.
124 ;;; And there have been some changes since the fork from CMU CL:
125 ;;; * The OpenBSD port is new since the fork. We started with
126 ;;; the FreeBSD address map, which actually worked until the
127 ;;; Alpha port patches, for reasons which in retrospect are rather
128 ;;; mysterious. After the Alpha port patches were added, the
129 ;;; OpenBSD port suffered memory corruption problems. While
130 ;;; debugging those, it was discovered that src/runtime/trymap
131 ;;; failed for the control stack region #x40000000-#x47fff000.
132 ;;; After the control stack was moved upward out of this region
133 ;;; (stealing some bytes from dynamic space) the problems went
135 ;;; * The FreeBSD STATIC-SPACE-START value was bumped up from
136 ;;; #x28000000 to #x30000000 when FreeBSD ld.so dynamic linking
137 ;;; support was added for FreeBSD ca. 20000910. This was to keep from
138 ;;; stomping on an address range that the dynamic libraries want to
139 ;;; use. (They want to use this address range even if we try to
140 ;;; reserve it with a call to validate() as the first operation in
142 ;;; * For NetBSD 2.0, the following ranges are used by normal
143 ;;; executables and mmap:
144 ;;; ** Executables are (by default) loaded at 0x08048000.
145 ;;; ** The break for the sbcl runtime seems to end around 0x08400000
146 ;;; We set read only space around 0x20000000, static
147 ;;; space around 0x30000000, all ending below 0x37fff000
148 ;;; ** ld.so and other mmap'ed stuff like shared libs start around
150 ;;; We set dynamic space between 0x60000000 and 0x98000000
151 ;;; ** Bottom of the stack is typically not below 0xb0000000
152 ;;; FYI, this can be looked at with the "pmap" program, and if you
153 ;;; set the top-down mmap allocation option in the kernel (not yet
154 ;;; the default), all bets are totally off!
155 ;;; * For FreeBSD, the requirement of user and kernel space are
156 ;;; getting larger, and users tend to extend them.
157 ;;; If MAXDSIZ is extended from 512MB to 1GB, we can't use up to
158 ;;; around 0x50000000.
159 ;;; And if KVA_PAGES is extended from 1GB to 1.5GB, we can't use
160 ;;; down to around 0xA0000000.
161 ;;; So we use 0x58000000--0x98000000 for dynamic space.
162 ;;; * OpenBSD address space changes for W^X as well as malloc()
163 ;;; randomization made the old addresses unsafe.
164 ;;; ** By default (linked without -Z option):
165 ;;; The executable's text segment starts at #x1c000000 and the
166 ;;; data segment MAXDSIZ bytes higher, at #x3c000000. Shared
167 ;;; library text segments start randomly between #x00002000 and
168 ;;; #x10002000, with the data segment MAXDSIZ bytes after that.
169 ;;; ** If the -Z linker option is used:
170 ;;; The executable's text and data segments simply start at
171 ;;; #x08048000, data immediately following text. Shared library
172 ;;; text and data is placed as if allocated by malloc().
173 ;;; ** In both cases, the randomized range for malloc() starts
174 ;;; MAXDSIZ bytes after the end of the data segment (#x48048000
175 ;;; with -Z, #x7c000000 without), and extends 256 MB.
176 ;;; ** The read only, static, and linkage table spaces should be
177 ;;; safe with and without -Z if they are located just before
179 ;;; ** Ideally the dynamic space should be at #x94000000, 64 MB
180 ;;; after the end of the highest random malloc() address.
181 ;;; Unfortunately the dynamic space must be in the lower half
182 ;;; of the address space, where there are no large areas which
183 ;;; are unused both with and without -Z. So we break -Z by
184 ;;; starting at #x40000000. By only using 512 - 64 MB we can
185 ;;; run under the default 512 MB data size resource limit.
187 ;;; NetBSD configuration used to have this comment regarding the linkage
188 ;;; table: "In CMUCL: 0xB0000000->0xB1000000"
190 #!+win32 (!gencgc-space-setup #x22000000 nil nil #x10000)
191 #!+linux (!gencgc-space-setup #x01000000 #x09000000)
192 #!+sunos (!gencgc-space-setup #x20000000 #x48000000)
193 #!+freebsd (!gencgc-space-setup #x01000000 #x58000000)
194 #!+openbsd (!gencgc-space-setup #x1b000000 #x40000000)
195 #!+netbsd (!gencgc-space-setup #x20000000 #x60000000)
196 #!+darwin (!gencgc-space-setup #x04000000 #x10000000)
198 ;;; Size of one linkage-table entry in bytes.
199 (def!constant linkage-table-entry-size 8)
201 ;;; Given that NIL is the first thing allocated in static space, we
202 ;;; know its value at compile time:
203 (def!constant nil-value (+ static-space-start #xb))
205 ;;;; other miscellaneous constants
209 pending-interrupt-trap
213 fun-end-breakpoint-trap
214 single-step-around-trap
215 single-step-before-trap)
219 object-not-instance-trap
220 #!+sb-safepoint global-safepoint-trap
221 #!+sb-safepoint csp-safepoint-trap)
225 ;;; These symbols are loaded into static space directly after NIL so
226 ;;; that the system can compute their address by adding a constant
229 ;;; The fdefn objects for the static functions are loaded into static
230 ;;; space directly after the static symbols. That way, the raw-addr
231 ;;; can be loaded directly out of them by indirecting relative to NIL.
233 ;;; pfw X86 doesn't have enough registers to keep these things there.
234 ;;; Note these spaces grow from low to high addresses.
235 (defvar *allocation-pointer*)
236 (defvar *binding-stack-pointer*)
238 (defparameter *static-symbols*
240 *common-static-symbols*
241 *c-callable-static-symbols*
244 ;; interrupt handling
248 *binding-stack-pointer*
250 ;; the floating point constants
255 ;; The following are all long-floats.
265 *restart-lisp-function*
267 ;; Needed for callbacks to work across saving cores. see
268 ;; ALIEN-CALLBACK-ASSEMBLER-WRAPPER in c-call.lisp for gory
270 sb!alien::*enter-alien-callback*
272 ;; see comments in ../x86-64/parms.lisp
273 sb!pcl::..slot-unbound..)))
275 (defparameter *static-funs*
286 sb!kernel:two-arg-and
287 sb!kernel:two-arg-ior
288 sb!kernel:two-arg-xor
289 sb!kernel:two-arg-gcd
290 sb!kernel:two-arg-lcm
291 sb!kernel:%coerce-callable-to-fun))
294 (defconstant +win32-tib-arbitrary-field-offset+ #.(+ #xE10 (* 4 63)))