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 (def!constant read-only-space-start #x20000000)
93 (def!constant read-only-space-end #x27ff0000)
95 (def!constant static-space-start #x40000000)
96 (def!constant static-space-end #x47fff000)
98 (def!constant dynamic-space-start #x1000000000)
99 (def!constant dynamic-space-end #x11ffff0000)
101 (def!constant linkage-table-space-start #x60000000)
102 (def!constant linkage-table-space-end #x63fff000)
104 (def!constant linkage-table-entry-size 16)
106 ;;;; other miscellaneous constants
108 (defenum (:suffix -trap :start 8)
115 single-step-breakpoint)
116 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something like
117 ;;; (WITH-DEF-ENUM (:START 8)
118 ;;; (DEF-ENUM HALT-TRAP)
119 ;;; (DEF-ENUM PENDING-INTERRUPT-TRAP)
121 ;;; for the benefit of anyone doing a lexical search for definitions
122 ;;; of these symbols.
124 (defenum (:prefix object-not- :suffix -trap :start 16)
128 (defenum (:prefix trace-table-)
136 ;;; These symbols are loaded into static space directly after NIL so
137 ;;; that the system can compute their address by adding a constant
140 ;;; The fdefn objects for the static functions are loaded into static
141 ;;; space directly after the static symbols. That way, the raw-addr
142 ;;; can be loaded directly out of them by indirecting relative to NIL.
144 ;;; we could profitably keep these in registers on x86-64 now we have
146 ;;; Note these spaces grow from low to high addresses.
147 (defvar *allocation-pointer*)
148 (defvar *binding-stack-pointer*)
150 ;;; FIXME: !COLD-INIT probably doesn't need
151 ;;; to be in the static symbols table any more.
153 ;;; FIXME: some of these symbols are shared by all backends,
154 ;;; and should be factored out into a common file.
155 (defparameter *static-symbols*
158 ;; The C startup code must fill these in.
161 ;; functions that the C code needs to call. When adding to this list,
162 ;; also add a `frob' form in genesis.lisp finish-symbols.
164 sb!kernel::internal-error
165 sb!kernel::control-stack-exhausted-error
166 sb!kernel::undefined-alien-variable-error
167 sb!kernel::undefined-alien-function-error
168 sb!kernel::memory-fault-error
169 sb!di::handle-breakpoint
171 #!+sb-thread sb!thread::handle-thread-exit
175 ;; Note that these are FIXNUM word counts, not (as one might
176 ;; expect) byte counts or SAPs. The reason seems to be that by
177 ;; representing them this way, we can avoid consing bignums.
179 *read-only-space-free-pointer*
180 *static-space-free-pointer*
181 *initial-dynamic-space-free-pointer*
183 ;; things needed for non-local exit
184 *current-catch-block*
185 *current-unwind-protect-block*
188 ;; interrupt handling
189 *pseudo-atomic-atomic*
190 *pseudo-atomic-interrupted*
191 sb!unix::*interrupts-enabled*
192 sb!unix::*interrupt-pending*
193 *free-interrupt-context-index*
198 *binding-stack-pointer*
199 *binding-stack-start*
200 *control-stack-start*
203 *need-to-collect-garbage*
205 ;; the floating point constants
211 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
212 ;; common slot unbound check.
214 ;; FIXME: In SBCL, the CLOS code has become sufficiently tightly
215 ;; integrated into the system that it'd probably make sense to use
216 ;; the ordinary unbound marker for this.
217 sb!pcl::..slot-unbound..))
219 (defparameter *static-funs*
230 sb!kernel:two-arg-and
231 sb!kernel:two-arg-ior
232 sb!kernel:two-arg-xor
233 sb!kernel:two-arg-gcd
234 sb!kernel:two-arg-lcm))