src/m/alpha.h

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