src/m/alpha.h

   1 /* machine description file For the alpha chip.
   2    Copyright (C) 1994, 1997, 1999, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007  Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22
  23 /* The following line tells the configuration script what sort of
  24    operating system this machine is likely to run.
  25    USUAL-OPSYS="note"
  26
  27 NOTE-START
  28 Use -opsystem=osf1
  29 NOTE-END
  30
  31 */
  32
  33 #ifndef _LP64
  34 #define _LP64                   /* This doesn't appear to be necessary
  35                                    on OSF 4/5  -- fx.  */
  36 #endif
  37
  38 /* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
  39    is the most significant byte.  */
  40
  41 #undef WORDS_BIG_ENDIAN
  42
  43 /* Define NO_ARG_ARRAY if you cannot take the address of the first of a
  44  * group of arguments and treat it as an array of the arguments.  */
  45
  46 #define NO_ARG_ARRAY
  47
  48 /* Now define a symbol for the cpu type, if your compiler
  49    does not define it automatically:
  50    Ones defined so far include vax, m68000, ns16000, pyramid,
  51    orion, tahoe, APOLLO and many others */
  52
  53 /* __alpha defined automatically */
  54
  55
  56 /* Use type EMACS_INT rather than a union, to represent Lisp_Object */
  57 /* This is desirable for most machines.  */
  58 #define NO_UNION_TYPE
  59
  60 /* Define EXPLICIT_SIGN_EXTEND if XINT must explicitly sign-extend
  61    the 24-bit bit field into an int.  In other words, if bit fields
  62    are always unsigned.
  63
  64    If you use NO_UNION_TYPE, this flag does not matter.  */
  65
  66 #define EXPLICIT_SIGN_EXTEND
  67
  68 /* Data type of load average, as read out of kmem.  */
  69
  70 #define LOAD_AVE_TYPE long
  71
  72 /* Convert that into an integer that is 100 for a load average of 1.0  */
  73
  74 #define LOAD_AVE_CVT(x) (int) (((double) (x)) * 100.0 / FSCALE)
  75
  76 /* GNU malloc and the relocating allocator do not work together
  77    with X.   [Who wrote that?]  */
  78
  79 /* May 1995: reportedly [Rainer Schoepf <schoepf@uni-mainz.de>] both the
  80    system and the gnu malloc system work with "alpha-dec-osf3.0" and
  81    "alpha-dec-osf3.2".  */
  82
  83 /* May 1995: it seems to me [Morten Welinder <terra@diku.dk>] that both
  84    mallocs work with "alpha-dec-osf2.0", but I daren't break anything
  85    right now.  Feel free to play if you want.  */
  86
  87 /* #define SYSTEM_MALLOC */
  88
  89 #ifdef __ELF__
  90 /* With ELF, make sure that all common symbols get allocated to in the
  91    data section.  Otherwise, the dump of temacs may miss variables in
  92    the shared library that have been initialized.  For example, with
  93    GNU libc, __malloc_initialized would normally be resolved to the
  94    shared library's .bss section, which is fatal.  */
  95 # ifdef __GNUC__
  96 #  define C_SWITCH_MACHINE      -fno-common
  97 # else
  98 #  error What gives?  Fix me if DEC Unix supports ELF now.
  99 # endif
 100 #endif
 101
 102 #if defined(__OpenBSD__)
 103 #define ORDINARY_LINK
 104 #endif
 105
 106 #ifdef __ELF__
 107 #undef UNEXEC
 108 #define UNEXEC unexelf.o
 109 #ifndef LINUX
 110 #define DATA_START    0x140000000
 111 #endif
 112 #endif
 113
 114 #ifndef __ELF__
 115
 116 /* Describe layout of the address space in an executing process.  */
 117
 118 #define TEXT_START    0x120000000
 119 #define DATA_START    0x140000000
 120
 121 /* The program to be used for unexec. */
 122
 123 #define UNEXEC unexalpha.o
 124
 125 #endif /* notdef __ELF__ */
 126
 127 #if defined (LINUX) && __GNU_LIBRARY__ - 0 < 6
 128 /* This controls a conditional in main.  */
 129 #define LINUX_SBRK_BUG
 130 #endif
 131
 132 /* On the Alpha it's best to avoid including TERMIO since struct
 133    termio and struct termios are mutually incompatible.  */
 134 #define NO_TERMIO
 135
 136 #if defined (LINUX) || defined (__NetBSD__) || defined (__OpenBSD__)
 137 # define TEXT_END ({ extern int _etext; &_etext; })
 138 # ifndef __ELF__
 139 #  define COFF
 140 #  define DATA_END ({ extern int _EDATA; &_EDATA; })
 141 # endif /* notdef __ELF__ */
 142 #endif
 143
 144 #if (defined (__NetBSD__) || defined (__OpenBSD__)) && defined (__ELF__)
 145 #define HAVE_TEXT_START
 146 #endif
 147
 148 /* Many Alpha implementations (e.g. gas 2.8) can't handle DBL_MIN:
 149    they generate code that uses a signaling NaN instead of DBL_MIN.
 150    Define DBL_MIN_REPLACEMENT to be the next value larger than DBL_MIN:
 151    this avoids the assembler bug.  */
 152 #define DBL_MIN_REPLACEMENT 2.2250738585072019e-308
 153
 154 /* arch-tag: 978cb578-1e25-4a60-819b-adae0972aa78
 155    (do not change this comment) */