code.delx.au - gnu-emacs/blob - src/m/alpha.h

   1 /* machine description file For the alpha chip.
   2    Copyright (C) 1994, 1997, 1999 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 1, or (at your option)
   9 any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 /* The following line tells the configuration script what sort of
  23    operating system this machine is likely to run.
  24    USUAL-OPSYS="note"
  25
  26 NOTE-START
  27 Use -opsystem=osf1
  28 NOTE-END
  29
  30 */
  31
  32 #define BITS_PER_LONG 64
  33 #define BITS_PER_EMACS_INT 64
  34
  35 /* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
  36    is the most significant byte.  */
  37
  38 #undef WORDS_BIG_ENDIAN
  39
  40 /* Define NO_ARG_ARRAY if you cannot take the address of the first of a
  41  * group of arguments and treat it as an array of the arguments.  */
  42
  43 #define NO_ARG_ARRAY
  44
  45 /* Define WORD_MACHINE if addresses and such have
  46  * to be corrected before they can be used as byte counts.  */
  47
  48 /* #define WORD_MACHINE */
  49
  50 /* Now define a symbol for the cpu type, if your compiler
  51    does not define it automatically:
  52    Ones defined so far include vax, m68000, ns16000, pyramid,
  53    orion, tahoe, APOLLO and many others */
  54
  55 /* __alpha defined automatically */
  56
  57
  58 /* Use type EMACS_INT rather than a union, to represent Lisp_Object */
  59 /* This is desirable for most machines.  */
  60
  61 #define NO_UNION_TYPE
  62
  63 /* Define the type to use.  */
  64 #define EMACS_INT long
  65 #define EMACS_UINT unsigned long
  66 #define SPECIAL_EMACS_INT
  67
  68 /* Define EXPLICIT_SIGN_EXTEND if XINT must explicitly sign-extend
  69    the 24-bit bit field into an int.  In other words, if bit fields
  70    are always unsigned.
  71
  72    If you use NO_UNION_TYPE, this flag does not matter.  */
  73
  74 #define EXPLICIT_SIGN_EXTEND
  75
  76 /* Data type of load average, as read out of kmem.  */
  77
  78 #define LOAD_AVE_TYPE long
  79
  80 /* Convert that into an integer that is 100 for a load average of 1.0  */
  81
  82 #define LOAD_AVE_CVT(x) (int) (((double) (x)) * 100.0 / FSCALE)
  83
  84 /* Define CANNOT_DUMP on machines where unexec does not work.
  85    Then the function dump-emacs will not be defined
  86    and temacs will do (load "loadup") automatically unless told otherwise.  */
  87
  88 /* #define CANNOT_DUMP */
  89
  90 /* Define VIRT_ADDR_VARIES if the virtual addresses of
  91    pure and impure space as loaded can vary, and even their
  92    relative order cannot be relied on.
  93
  94    Otherwise Emacs assumes that text space precedes data space,
  95    numerically.  */
  96
  97 /* #define VIRT_ADDR_VARIES */
  98
  99 /* Define C_ALLOCA if this machine does not support a true alloca
 100    and the one written in C should be used instead.
 101    Define HAVE_ALLOCA to say that the system provides a properly
 102    working alloca function and it should be used.
 103    Define neither one if an assembler-language alloca
 104    in the file alloca.s should be used.  */
 105
 106 #define HAVE_ALLOCA
 107
 108 /* GNU malloc and the relocating allocator do not work together
 109    with X.   [Who wrote that?]  */
 110
 111 /* May 1995: reportedly [Rainer Schoepf <schoepf@uni-mainz.de>] both the
 112    system and the gnu malloc system work with "alpha-dec-osf3.0" and
 113    "alpha-dec-osf3.2".  */
 114
 115 /* May 1995: it seems to me [Morten Welinder <terra@diku.dk>] that both
 116    mallocs work with "alpha-dec-osf2.0", but I daren't break anything
 117    right now.  Feel free to play if you want.  */
 118
 119 /* #define SYSTEM_MALLOC */
 120
 121 /* Define NO_REMAP if memory segmentation makes it not work well
 122    to change the boundary between the text section and data section
 123    when Emacs is dumped.  If you define this, the preloaded Lisp
 124    code will not be sharable; but that's better than failing completely.  */
 125
 126 #define NO_REMAP
 127
 128 /* Some really obscure 4.2-based systems (like Sequent DYNIX)
 129  * do not support asynchronous I/O (using SIGIO) on sockets,
 130  * even though it works fine on tty's.  If you have one of
 131  * these systems, define the following, and then use it in
 132  * config.h (or elsewhere) to decide when (not) to use SIGIO.
 133  *
 134  * You'd think this would go in an operating-system description file,
 135  * but since it only occurs on some, but not all, BSD systems, the
 136  * reasonable place to select for it is in the machine description
 137  * file.
 138  */
 139
 140 /* #define NO_SOCK_SIGIO */
 141
 142
 143 #ifdef __ELF__
 144 /* With ELF, make sure that all common symbols get allocated to in the
 145    data section.  Otherwise, the dump of temacs may miss variables in
 146    the shared library that have been initialized.  For example, with
 147    GNU libc, __malloc_initialized would normally be resolved to the
 148    shared library's .bss section, which is fatal.  */
 149 # ifdef __GNUC__
 150 #  define C_SWITCH_MACHINE      -fno-common
 151 # else
 152 #  error What gives?  Fix me if DEC Unix supports ELF now.
 153 # endif
 154 #endif
 155
 156 #if defined(__NetBSD__) || defined(__OpenBSD__)
 157 #define ORDINARY_LINK
 158 #endif
 159
 160 #ifdef __ELF__
 161 #undef UNEXEC
 162 #define UNEXEC unexelf.o
 163 #endif
 164
 165 #ifndef __ELF__
 166
 167 /* Describe layout of the address space in an executing process.  */
 168
 169 #define TEXT_START    0x120000000
 170 #define DATA_START    0x140000000
 171
 172 /* This is necessary for mem-limits.h, so that start_of_data gives
 173    the correct value */
 174
 175 #define DATA_SEG_BITS 0x140000000
 176
 177 /* The program to be used for unexec. */
 178
 179 #define UNEXEC unexalpha.o
 180
 181 #endif /* notdef __ELF__ */
 182
 183 #ifdef OSF1
 184 #define ORDINARY_LINK
 185
 186 /* Some systems seem to have this, others don't.  */
 187 #ifdef HAVE_LIBDNET
 188 #define LIBS_MACHINE -ldnet
 189 #else
 190 #define LIBS_MACHINE -ldnet_stub
 191 #endif
 192 #endif /* OSF1 */
 193
 194 #if 0 /* Rainer Schoepf <schoepf@uni-mainz.de> says this loses with X11R6
 195          since it has only shared libraries.  */
 196 #ifndef __GNUC__
 197 /* This apparently is for the system ld as opposed to Gnu ld.  */
 198 #ifdef OSF1
 199 #define LD_SWITCH_MACHINE      -non_shared
 200 #endif
 201 #endif
 202 #endif /* 0 */
 203
 204 #ifdef OSF1
 205 #define LIBS_DEBUG
 206 #define START_FILES pre-crt0.o
 207 #endif
 208
 209 #if defined (LINUX) && __GNU_LIBRARY__ - 0 < 6
 210 /* This controls a conditional in main.  */
 211 #define LINUX_SBRK_BUG
 212 #endif
 213
 214
 215 #define PNTR_COMPARISON_TYPE unsigned long
 216
 217 /* On the 64 bit architecture, we can use 60 bits for addresses */
 218
 219 #define VALBITS         60
 220
 221
 222 /* This definition of MARKBIT is necessary because of the comparison of
 223    ARRAY_MARK_FLAG and MARKBIT in an #if in lisp.h, which cpp doesn't like. */
 224
 225 #define MARKBIT         0x8000000000000000L
 226
 227
 228 /* Define XINT and XUINT so that they can take arguments of type int */
 229
 230 #define XINT(a)  (((long) (a) << (BITS_PER_LONG - VALBITS)) >> (BITS_PER_LONG - VALBITS))
 231 #define XUINT(a) ((long) (a) & VALMASK)
 232
 233 /* Define XPNTR to avoid or'ing with DATA_SEG_BITS */
 234
 235 #define XPNTR(a) XUINT (a)
 236
 237 #ifndef NOT_C_CODE
 238 /* We need these because pointers are larger than the default ints.  */
 239 #if !defined(__NetBSD__) && !defined(__OpenBSD__)
 240 #include <alloca.h>
 241 #endif
 242
 243 /* Hack alert!  For reasons unknown to mankind the string.h file insists
 244    on defining bcopy etc. as taking char pointers as arguments.  With
 245    Emacs this produces an endless amount of warning which are harmless,
 246    but tends to flood the real errors.  This hack works around this problem
 247    by not prototyping.  */
 248 #define bcopy string_h_bcopy
 249 #define bzero string_h_bzero
 250 #define bcmp  string_h_bcmp
 251 #include <string.h>
 252 #undef bcopy
 253 #undef bzero
 254 #undef bcmp
 255
 256 extern long *xmalloc (), *xrealloc ();
 257
 258 #ifdef REL_ALLOC
 259 #ifndef _MALLOC_INTERNAL
 260 /* "char *" because ralloc.c defines it that way.  gmalloc.c thinks it
 261    is allowed to prototype these as "void *" so we don't prototype in
 262    that case.  You're right: it stinks!  */
 263 extern char *r_alloc (), *r_re_alloc ();
 264 extern void r_alloc_free ();
 265 #endif /* not _MALLOC_INTERNAL */
 266 #endif /* REL_ALLOC */
 267
 268 #endif /* not NOT_C_CODE */
 269
 270 #ifdef OSF1
 271 #define PTY_ITERATION           for (i = 0; i < 1; i++) /* ick */
 272 #define PTY_NAME_SPRINTF        /* none */
 273 #define PTY_TTY_NAME_SPRINTF    /* none */
 274 #define PTY_OPEN                                        \
 275   do                                                    \
 276     {                                                   \
 277       int dummy;                                        \
 278       SIGMASKTYPE mask;                                 \
 279       mask = sigblock (sigmask (SIGCHLD));              \
 280       if (-1 == openpty (&fd, &dummy, pty_name, 0, 0))  \
 281         fd = -1;                                        \
 282       sigsetmask (mask);                                \
 283       emacs_close (dummy);                              \
 284     }                                                   \
 285   while (0)
 286 #endif
 287
 288 /* On the Alpha it's best to avoid including TERMIO since struct
 289    termio and struct termios are mutually incompatible.  */
 290 #define NO_TERMIO
 291
 292 #if defined (LINUX) || defined (__NetBSD__) || defined (__OpenBSD__)
 293 # define TEXT_END ({ extern int _etext; &_etext; })
 294 # ifndef __ELF__
 295 #  define COFF
 296 #  define DATA_END ({ extern int _EDATA; &_EDATA; })
 297 # endif /* notdef __ELF__ */
 298 #endif
 299
 300 #if (defined (__NetBSD__) || defined (__OpenBSD__)) && defined (__ELF__)
 301 #define HAVE_TEXT_START
 302 #endif
 303
 304 /* Many Alpha implementations (e.g. gas 2.8) can't handle DBL_MIN:
 305    they generate code that uses a signaling NaN instead of DBL_MIN.
 306    Define DBL_MIN_REPLACEMENT to be the next value larger than DBL_MIN:
 307    this avoids the assembler bug.  */
 308 #define DBL_MIN_REPLACEMENT 2.2250738585072019e-308