5a0168417cb2adf35db6c3f12a6e339dc211a851
[bpt/emacs.git] / src / m / alpha.h
1 /* Machine description file for the alpha chip.
2
3 Copyright (C) 1994, 1997, 1999, 2001, 2002, 2003, 2004, 2005, 2006,
4 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
5
6 Author: Rainer Schoepf
7 (according to authors.el)
8
9 This file is part of GNU Emacs.
10
11 GNU Emacs is free software: you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation, either version 3 of the License, or
14 (at your option) any later version.
15
16 GNU Emacs is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
23
24 #ifndef _LP64
25 #define _LP64 /* This doesn't appear to be necessary on OSF 4/5 -- fx. */
26 #endif
27
28 /* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
29 is the most significant byte. */
30 #undef WORDS_BIG_ENDIAN
31
32 /* Now define a symbol for the cpu type, if your compiler
33 does not define it automatically. */
34 /* __alpha defined automatically */
35
36
37 /* Define EXPLICIT_SIGN_EXTEND if XINT must explicitly sign-extend
38 the 24-bit bit field into an int. In other words, if bit fields
39 are always unsigned.
40
41 This flag only matters if you use USE_LISP_UNION_TYPE. */
42 #define EXPLICIT_SIGN_EXTEND
43
44 /* Data type of load average, as read out of kmem. */
45 #define LOAD_AVE_TYPE long
46
47 /* Convert that into an integer that is 100 for a load average of 1.0 */
48 #define LOAD_AVE_CVT(x) (int) (((double) (x)) * 100.0 / FSCALE)
49
50 #ifdef __ELF__
51
52 #if !defined(GNU_LINUX) && !defined(__NetBSD__)
53 #define DATA_START 0x140000000
54 #endif
55
56 #else /* not __ELF__ */
57
58 /* Describe layout of the address space in an executing process. */
59 #define DATA_START 0x140000000
60
61 #endif /* __ELF__ */
62
63 /* On the Alpha it's best to avoid including TERMIO since struct
64 termio and struct termios are mutually incompatible. */
65 #define NO_TERMIO
66
67 /* Many Alpha implementations (e.g. gas 2.8) can't handle DBL_MIN:
68 they generate code that uses a signaling NaN instead of DBL_MIN.
69 Define DBL_MIN_REPLACEMENT to be the next value larger than DBL_MIN:
70 this avoids the assembler bug. */
71 #define DBL_MIN_REPLACEMENT 2.2250738585072019e-308
72
73 /* arch-tag: 978cb578-1e25-4a60-819b-adae0972aa78
74 (do not change this comment) */