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 #ifndef _LP64
  35 #define _LP64                   /* This doesn't appear to be necessary
  36                                    on OSF 4/5  -- fx.  */
  37 #endif
  38
  39 /* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
  40    is the most significant byte.  */
  41
  42 #undef WORDS_BIG_ENDIAN
  43
  44 /* Define NO_ARG_ARRAY if you cannot take the address of the first of a
  45  * group of arguments and treat it as an array of the arguments.  */
  46
  47 #define NO_ARG_ARRAY
  48
  49 /* Now define a symbol for the cpu type, if your compiler
  50    does not define it automatically:
  51    Ones defined so far include vax, m68000, ns16000, pyramid,
  52    orion, tahoe, APOLLO and many others */
  53
  54 /* __alpha defined automatically */
  55
  56
  57 /* Use type EMACS_INT rather than a union, to represent Lisp_Object */
  58 /* This is desirable for most machines.  */
  59
  60 #define NO_UNION_TYPE
  61
  62 /* Define the type to use.  */
  63 #define EMACS_INT long
  64 #define EMACS_UINT unsigned long
  65 #define SPECIAL_EMACS_INT
  66
  67 /* Define EXPLICIT_SIGN_EXTEND if XINT must explicitly sign-extend
  68    the 24-bit bit field into an int.  In other words, if bit fields
  69    are always unsigned.
  70
  71    If you use NO_UNION_TYPE, this flag does not matter.  */
  72
  73 #define EXPLICIT_SIGN_EXTEND
  74
  75 /* Data type of load average, as read out of kmem.  */
  76
  77 #define LOAD_AVE_TYPE long
  78
  79 /* Convert that into an integer that is 100 for a load average of 1.0  */
  80
  81 #define LOAD_AVE_CVT(x) (int) (((double) (x)) * 100.0 / FSCALE)
  82
  83 /* Define C_ALLOCA if this machine does not support a true alloca
  84    and the one written in C should be used instead.
  85    Define HAVE_ALLOCA to say that the system provides a properly
  86    working alloca function and it should be used.
  87    Define neither one if an assembler-language alloca
  88    in the file alloca.s should be used.  */
  89
  90 #define HAVE_ALLOCA
  91
  92 /* GNU malloc and the relocating allocator do not work together
  93    with X.   [Who wrote that?]  */
  94
  95 /* May 1995: reportedly [Rainer Schoepf <schoepf@uni-mainz.de>] both the
  96    system and the gnu malloc system work with "alpha-dec-osf3.0" and
  97    "alpha-dec-osf3.2".  */
  98
  99 /* May 1995: it seems to me [Morten Welinder <terra@diku.dk>] that both
 100    mallocs work with "alpha-dec-osf2.0", but I daren't break anything
 101    right now.  Feel free to play if you want.  */
 102
 103 /* #define SYSTEM_MALLOC */
 104
 105 #ifdef __ELF__
 106 /* With ELF, make sure that all common symbols get allocated to in the
 107    data section.  Otherwise, the dump of temacs may miss variables in
 108    the shared library that have been initialized.  For example, with
 109    GNU libc, __malloc_initialized would normally be resolved to the
 110    shared library's .bss section, which is fatal.  */
 111 # ifdef __GNUC__
 112 #  define C_SWITCH_MACHINE      -fno-common
 113 # else
 114 #  error What gives?  Fix me if DEC Unix supports ELF now.
 115 # endif
 116 #endif
 117
 118 #if defined(__OpenBSD__)
 119 #define ORDINARY_LINK
 120 #endif
 121
 122 #ifdef __ELF__
 123 #undef UNEXEC
 124 #define UNEXEC unexelf.o
 125 #endif
 126
 127 #ifndef __ELF__
 128
 129 /* Describe layout of the address space in an executing process.  */
 130
 131 #define TEXT_START    0x120000000
 132 #define DATA_START    0x140000000
 133
 134 /* This is necessary for mem-limits.h, so that start_of_data gives
 135    the correct value */
 136
 137 #define DATA_SEG_BITS 0x140000000
 138
 139 /* The program to be used for unexec. */
 140
 141 #define UNEXEC unexalpha.o
 142
 143 #endif /* notdef __ELF__ */
 144
 145 #ifdef OSF1
 146 #define ORDINARY_LINK
 147
 148 /* Some systems seem to have this, others don't.  */
 149 #ifdef HAVE_LIBDNET
 150 #define LIBS_MACHINE -ldnet
 151 #else
 152 #define LIBS_MACHINE -ldnet_stub
 153 #endif
 154 #endif /* OSF1 */
 155
 156 #if 0 /* Rainer Schoepf <schoepf@uni-mainz.de> says this loses with X11R6
 157          since it has only shared libraries.  */
 158 #ifndef __GNUC__
 159 /* This apparently is for the system ld as opposed to Gnu ld.  */
 160 #ifdef OSF1
 161 #define LD_SWITCH_MACHINE      -non_shared
 162 #endif
 163 #endif
 164 #endif /* 0 */
 165
 166 #ifdef OSF1
 167 #define LIBS_DEBUG
 168 #define START_FILES pre-crt0.o
 169 #endif
 170
 171 #if defined (LINUX) && __GNU_LIBRARY__ - 0 < 6
 172 /* This controls a conditional in main.  */
 173 #define LINUX_SBRK_BUG
 174 #endif
 175
 176
 177 #define PNTR_COMPARISON_TYPE unsigned long
 178
 179 /* On the 64 bit architecture, we can use 60 bits for addresses */
 180
 181 #define VALBITS         60
 182
 183
 184 /* This definition of MARKBIT is necessary because of the comparison of
 185    ARRAY_MARK_FLAG and MARKBIT in an #if in lisp.h, which cpp doesn't like. */
 186
 187 #define MARKBIT         0x8000000000000000L
 188
 189
 190 /* Define XINT and XUINT so that they can take arguments of type int */
 191
 192 #define XINT(a)  (((long) (a) << (BITS_PER_LONG - VALBITS)) >> (BITS_PER_LONG - VALBITS))
 193 #define XUINT(a) ((long) (a) & VALMASK)
 194
 195 /* Define XPNTR to avoid or'ing with DATA_SEG_BITS */
 196
 197 #define XPNTR(a) XUINT (a)
 198
 199 #ifndef NOT_C_CODE
 200 /* We need these because pointers are larger than the default ints.  */
 201 #if !defined(__NetBSD__) && !defined(__OpenBSD__)
 202 #include <alloca.h>
 203 #endif
 204
 205 #endif /* not NOT_C_CODE */
 206
 207 #ifdef OSF1
 208 #define PTY_ITERATION           for (i = 0; i < 1; i++) /* ick */
 209 #define PTY_NAME_SPRINTF        /* none */
 210 #define PTY_TTY_NAME_SPRINTF    /* none */
 211 #define PTY_OPEN                                        \
 212   do                                                    \
 213     {                                                   \
 214       int dummy;                                        \
 215       SIGMASKTYPE mask;                                 \
 216       mask = sigblock (sigmask (SIGCHLD));              \
 217       if (-1 == openpty (&fd, &dummy, pty_name, 0, 0))  \
 218         fd = -1;                                        \
 219       sigsetmask (mask);                                \
 220       emacs_close (dummy);                              \
 221     }                                                   \
 222   while (0)
 223 #endif
 224
 225 /* On the Alpha it's best to avoid including TERMIO since struct
 226    termio and struct termios are mutually incompatible.  */
 227 #define NO_TERMIO
 228
 229 #if defined (LINUX) || defined (__NetBSD__) || defined (__OpenBSD__)
 230 # define TEXT_END ({ extern int _etext; &_etext; })
 231 # ifndef __ELF__
 232 #  define COFF
 233 #  define DATA_END ({ extern int _EDATA; &_EDATA; })
 234 # endif /* notdef __ELF__ */
 235 #endif
 236
 237 #if (defined (__NetBSD__) || defined (__OpenBSD__)) && defined (__ELF__)
 238 #define HAVE_TEXT_START
 239 #endif
 240
 241 /* Many Alpha implementations (e.g. gas 2.8) can't handle DBL_MIN:
 242    they generate code that uses a signaling NaN instead of DBL_MIN.
 243    Define DBL_MIN_REPLACEMENT to be the next value larger than DBL_MIN:
 244    this avoids the assembler bug.  */
 245 #define DBL_MIN_REPLACEMENT 2.2250738585072019e-308