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 64 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 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 single-float-digits
70 (+ (byte-size single-float-significand-byte) 1))
72 (def!constant double-float-digits
73 (+ (byte-size double-float-significand-byte) 32 1))
75 ;;; from AMD64 Architecture manual
76 (def!constant float-invalid-trap-bit (ash 1 0))
77 (def!constant float-denormal-trap-bit (ash 1 1))
78 (def!constant float-divide-by-zero-trap-bit (ash 1 2))
79 (def!constant float-overflow-trap-bit (ash 1 3))
80 (def!constant float-underflow-trap-bit (ash 1 4))
81 (def!constant float-inexact-trap-bit (ash 1 5))
83 (def!constant float-round-to-nearest 0)
84 (def!constant float-round-to-negative 1)
85 (def!constant float-round-to-positive 2)
86 (def!constant float-round-to-zero 3)
88 (defconstant-eqx float-rounding-mode (byte 2 13) #'equalp)
89 (defconstant-eqx float-sticky-bits (byte 6 0) #'equalp)
90 (defconstant-eqx float-traps-byte (byte 6 7) #'equalp)
91 (defconstant-eqx float-exceptions-byte (byte 6 0) #'equalp)
92 (def!constant float-fast-bit 0) ; no fast mode on x86-64
94 ;;;; description of the target address space
96 ;;; where to put the different spaces.
98 ;;; Currently the read-only and static spaces must be located in low
99 ;;; memory (certainly under the 4GB limit, very probably under 2GB
100 ;;; limit). This is due to the inability of using immediate values of
101 ;;; more than 32 bits (31 bits if you take sign extension into
102 ;;; account) in any other instructions except MOV. Removing this limit
103 ;;; would be possible, but probably not worth the time and code bloat
104 ;;; it would cause. -- JES, 2005-12-11
106 ;;; The default dynamic space size is lower on OpenBSD to allow SBCL to
107 ;;; run under the default 512M data size limit.
109 (!gencgc-space-setup #x20000000
112 ;; :default-dynamic-space-size
113 #!+openbsd #x1bcf0000
116 #!+win32 #!+win32 nil #x10000)
118 (def!constant linkage-table-entry-size 16)
121 ;;;; other miscellaneous constants
125 pending-interrupt-trap
129 fun-end-breakpoint-trap
130 single-step-around-trap
131 single-step-before-trap)
135 object-not-instance-trap
136 #!+sb-safepoint global-safepoint-trap
137 #!+sb-safepoint csp-safepoint-trap)
141 ;;; These symbols are loaded into static space directly after NIL so
142 ;;; that the system can compute their address by adding a constant
145 ;;; The fdefn objects for the static functions are loaded into static
146 ;;; space directly after the static symbols. That way, the raw-addr
147 ;;; can be loaded directly out of them by indirecting relative to NIL.
149 ;;; we could profitably keep these in registers on x86-64 now we have
151 ;;; Note these spaces grow from low to high addresses.
152 (defvar *allocation-pointer*)
153 (defvar *binding-stack-pointer*)
155 (defparameter *static-symbols*
157 *common-static-symbols*
158 *c-callable-static-symbols*
161 ;; interrupt handling
165 *binding-stack-pointer*
167 ;; the floating point constants
174 *restart-lisp-function*
176 ;; Needed for callbacks to work across saving cores. see
177 ;; ALIEN-CALLBACK-ASSEMBLER-WRAPPER in c-call.lisp for gory
179 sb!alien::*enter-alien-callback*
181 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
182 ;; common slot unbound check.
184 ;; FIXME: In SBCL, the CLOS code has become sufficiently tightly
185 ;; integrated into the system that it'd probably make sense to
186 ;; use the ordinary unbound marker for this.
188 ;; FIXME II: if it doesn't make sense, why is this X86-ish only?
189 sb!pcl::..slot-unbound..)))
191 (defparameter *static-funs*
202 sb!kernel:two-arg-and
203 sb!kernel:two-arg-ior
204 sb!kernel:two-arg-xor
205 sb!kernel:two-arg-gcd
206 sb!kernel:two-arg-lcm
207 sb!kernel:%coerce-callable-to-fun))
210 (defvar *simd-pack-element-types* '(integer single-float double-float))