src/m/m68k.h

   1 /* Machine description file for generic Motorola 68k.
   2    Copyright (C) 1985, 1995 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 2, 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 three symbols give information on
  23  the size of various data types.  */
  24
  25
  26 /* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
  27    is the most significant byte.  */
  28
  29 #define WORDS_BIG_ENDIAN
  30
  31 /* Define NO_ARG_ARRAY if you cannot take the address of the first of a
  32  * group of arguments and treat it as an array of the arguments.  */
  33
  34 /* #define NO_ARG_ARRAY */
  35
  36 /* Define WORD_MACHINE if addresses and such have
  37  * to be corrected before they can be used as byte counts.  */
  38
  39 /* #define WORD_MACHINE */
  40
  41 /* Now define a symbol for the cpu type, if your compiler
  42    does not define it automatically.  */
  43
  44 #ifndef m68k
  45 #define m68k
  46 #endif
  47
  48 /* Use type int rather than a union, to represent Lisp_Object */
  49 /* This is desirable for most machines.  */
  50
  51 #define NO_UNION_TYPE
  52
  53 /* Define EXPLICIT_SIGN_EXTEND if XINT must explicitly sign-extend
  54    the 24-bit bit field into an int.  In other words, if bit fields
  55    are always unsigned.
  56
  57    If you use NO_UNION_TYPE, this flag does not matter.  */
  58
  59 #define EXPLICIT_SIGN_EXTEND
  60
  61 /* Define CANNOT_DUMP on machines where unexec does not work.
  62    Then the function dump-emacs will not be defined
  63    and temacs will do (load "loadup") automatically unless told otherwise.  */
  64
  65 /* #define CANNOT_DUMP */
  66
  67 /* Define VIRT_ADDR_VARIES if the virtual addresses of
  68    pure and impure space as loaded can vary, and even their
  69    relative order cannot be relied on.
  70
  71    Otherwise Emacs assumes that text space precedes data space,
  72    numerically.  */
  73
  74 /* #define VIRT_ADDR_VARIES */
  75
  76 #ifdef linux
  77 #ifdef __ELF__
  78 #define DATA_SEG_BITS 0x80000000
  79 #endif
  80
  81 #define NO_REMAP
  82 #define TEXT_START 0
  83 #endif
  84
  85 /* If compiling with GCC, let GCC implement alloca.  */
  86 #if defined(__GNUC__) && !defined(alloca)
  87 #define alloca(n) __builtin_alloca(n)
  88 #define HAVE_ALLOCA
  89 #endif