src/m/alpha.h

   1 /* machine description file For the alpha chip.
   2    Copyright (C) 1994, 1997, 1999, 2001, 2002, 2003, 2004, 2005, 2006,
   3                  2007, 2008  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 of the License, or
  10 (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20
  21 /* The following line tells the configuration script what sort of
  22    operating system this machine is likely to run.
  23    USUAL-OPSYS="note"
  24
  25 NOTE-START
  26 Use -opsystem=osf1
  27 NOTE-END
  28
  29 */
  30
  31 #ifndef _LP64
  32 #define _LP64                   /* This doesn't appear to be necessary
  33                                    on OSF 4/5  -- fx.  */
  34 #endif
  35
  36 /* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
  37    is the most significant byte.  */
  38
  39 #undef WORDS_BIG_ENDIAN
  40
  41 /* Define NO_ARG_ARRAY if you cannot take the address of the first of a
  42  * group of arguments and treat it as an array of the arguments.  */
  43
  44 #define NO_ARG_ARRAY
  45
  46 /* Now define a symbol for the cpu type, if your compiler
  47    does not define it automatically:
  48    Ones defined so far include vax, m68000, ns16000, pyramid,
  49    orion, tahoe, APOLLO and many others */
  50
  51 /* __alpha defined automatically */
  52
  53
  54 /* Use type EMACS_INT rather than a union, to represent Lisp_Object */
  55 /* This is desirable for most machines.  */
  56 #define NO_UNION_TYPE
  57
  58 /* Define EXPLICIT_SIGN_EXTEND if XINT must explicitly sign-extend
  59    the 24-bit bit field into an int.  In other words, if bit fields
  60    are always unsigned.
  61
  62    If you use NO_UNION_TYPE, this flag does not matter.  */
  63
  64 #define EXPLICIT_SIGN_EXTEND
  65
  66 /* Data type of load average, as read out of kmem.  */
  67
  68 #define LOAD_AVE_TYPE long
  69
  70 /* Convert that into an integer that is 100 for a load average of 1.0  */
  71
  72 #define LOAD_AVE_CVT(x) (int) (((double) (x)) * 100.0 / FSCALE)
  73
  74 /* GNU malloc and the relocating allocator do not work together
  75    with X.   [Who wrote that?]  */
  76
  77 /* May 1995: reportedly [Rainer Schoepf <schoepf@uni-mainz.de>] both the
  78    system and the gnu malloc system work with "alpha-dec-osf3.0" and
  79    "alpha-dec-osf3.2".  */
  80
  81 /* May 1995: it seems to me [Morten Welinder <terra@diku.dk>] that both
  82    mallocs work with "alpha-dec-osf2.0", but I daren't break anything
  83    right now.  Feel free to play if you want.  */
  84
  85 /* #define SYSTEM_MALLOC */
  86
  87 #ifdef __ELF__
  88 /* With ELF, make sure that all common symbols get allocated to in the
  89    data section.  Otherwise, the dump of temacs may miss variables in
  90    the shared library that have been initialized.  For example, with
  91    GNU libc, __malloc_initialized would normally be resolved to the
  92    shared library's .bss section, which is fatal.  */
  93 # ifdef __GNUC__
  94 #  define C_SWITCH_MACHINE      -fno-common
  95 # else
  96 #  error What gives?  Fix me if DEC Unix supports ELF now.
  97 # endif
  98 #endif
  99
 100 #ifdef __ELF__
 101 #undef UNEXEC
 102 #define UNEXEC unexelf.o
 103 #ifndef LINUX
 104 #define DATA_START    0x140000000
 105 #endif
 106 #endif
 107
 108 #ifndef __ELF__
 109
 110 /* Describe layout of the address space in an executing process.  */
 111
 112 #define TEXT_START    0x120000000
 113 #define DATA_START    0x140000000
 114
 115 /* The program to be used for unexec. */
 116
 117 #define UNEXEC unexalpha.o
 118
 119 #endif /* notdef __ELF__ */
 120
 121 #if defined (LINUX) && __GNU_LIBRARY__ - 0 < 6
 122 /* This controls a conditional in main.  */
 123 #define LINUX_SBRK_BUG
 124 #endif
 125
 126 /* On the Alpha it's best to avoid including TERMIO since struct
 127    termio and struct termios are mutually incompatible.  */
 128 #define NO_TERMIO
 129
 130 #if defined (LINUX) || defined (__NetBSD__) || defined (__OpenBSD__)
 131 # define TEXT_END ({ extern int _etext; &_etext; })
 132 # ifndef __ELF__
 133 #  define COFF
 134 #  define DATA_END ({ extern int _EDATA; &_EDATA; })
 135 # endif /* notdef __ELF__ */
 136 #endif
 137
 138 #if (defined (__NetBSD__) || defined (__OpenBSD__)) && defined (__ELF__)
 139 #define HAVE_TEXT_START
 140 #endif
 141
 142 /* Many Alpha implementations (e.g. gas 2.8) can't handle DBL_MIN:
 143    they generate code that uses a signaling NaN instead of DBL_MIN.
 144    Define DBL_MIN_REPLACEMENT to be the next value larger than DBL_MIN:
 145    this avoids the assembler bug.  */
 146 #define DBL_MIN_REPLACEMENT 2.2250738585072019e-308
 147
 148 /* arch-tag: 978cb578-1e25-4a60-819b-adae0972aa78
 149    (do not change this comment) */