added port of dosfsck. Does not work yet as I cannot figure how to open the device...
[reactos.git] / rosapps / sysutils / dosfsck / byteswap1.h
1 /* Macros to swap the order of bytes in integer values.
2 Copyright (C) 1997, 1998, 2000, 2002, 2003 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
19
20 #if !defined _BYTESWAP_H && !defined _NETINET_IN_H
21 # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
22 #endif
23
24 #ifndef _BITS_BYTESWAP_H
25 #define _BITS_BYTESWAP_H 1
26
27 /* Swap bytes in 16 bit value. */
28 #define __bswap_constant_16(x) \
29 ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))
30
31 #ifdef __GNUC__
32 # if __GNUC__ >= 2
33 # define __bswap_16(x) \
34 (__extension__ \
35 ({ register unsigned short int __v, __x = (x); \
36 if (__builtin_constant_p (__x)) \
37 __v = __bswap_constant_16 (__x); \
38 else \
39 __asm__ ("rorw $8, %w0" \
40 : "=r" (__v) \
41 : "0" (__x) \
42 : "cc"); \
43 __v; }))
44 # else
45 /* This is better than nothing. */
46 # define __bswap_16(x) \
47 (__extension__ \
48 ({ register unsigned short int __x = (x); __bswap_constant_16 (__x); }))
49 # endif
50 #else
51 static __inline unsigned short int
52 __bswap_16 (unsigned short int __bsx)
53 {
54 return __bswap_constant_16 (__bsx);
55 }
56 #endif
57
58 /* Swap bytes in 32 bit value. */
59 #define __bswap_constant_32(x) \
60 ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \
61 (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
62
63 #ifdef __GNUC__
64 # if __GNUC__ >= 2
65 /* To swap the bytes in a word the i486 processors and up provide the
66 `bswap' opcode. On i386 we have to use three instructions. */
67 # if !defined __i486__ && !defined __pentium__ && !defined __pentiumpro__ \
68 && !defined __pentium4__
69 # define __bswap_32(x) \
70 (__extension__ \
71 ({ register unsigned int __v, __x = (x); \
72 if (__builtin_constant_p (__x)) \
73 __v = __bswap_constant_32 (__x); \
74 else \
75 __asm__ ("rorw $8, %w0;" \
76 "rorl $16, %0;" \
77 "rorw $8, %w0" \
78 : "=r" (__v) \
79 : "0" (__x) \
80 : "cc"); \
81 __v; }))
82 # else
83 # define __bswap_32(x) \
84 (__extension__ \
85 ({ register unsigned int __v, __x = (x); \
86 if (__builtin_constant_p (__x)) \
87 __v = __bswap_constant_32 (__x); \
88 else \
89 __asm__ ("bswap %0" : "=r" (__v) : "0" (__x)); \
90 __v; }))
91 # endif
92 # else
93 # define __bswap_32(x) \
94 (__extension__ \
95 ({ register unsigned int __x = (x); __bswap_constant_32 (__x); }))
96 # endif
97 #else
98 static __inline unsigned int
99 __bswap_32 (unsigned int __bsx)
100 {
101 return __bswap_constant_32 (__bsx);
102 }
103 #endif
104
105
106 #if defined __GNUC__ && __GNUC__ >= 2
107 /* Swap bytes in 64 bit value. */
108 #define __bswap_constant_64(x) \
109 ((((x) & 0xff00000000000000ull) >> 56) \
110 | (((x) & 0x00ff000000000000ull) >> 40) \
111 | (((x) & 0x0000ff0000000000ull) >> 24) \
112 | (((x) & 0x000000ff00000000ull) >> 8) \
113 | (((x) & 0x00000000ff000000ull) << 8) \
114 | (((x) & 0x0000000000ff0000ull) << 24) \
115 | (((x) & 0x000000000000ff00ull) << 40) \
116 | (((x) & 0x00000000000000ffull) << 56))
117
118 # define __bswap_64(x) \
119 (__extension__ \
120 ({ union { __extension__ unsigned long long int __ll; \
121 unsigned long int __l[2]; } __w, __r; \
122 if (__builtin_constant_p (x)) \
123 __r.__ll = __bswap_constant_64 (x); \
124 else \
125 { \
126 __w.__ll = (x); \
127 __r.__l[0] = __bswap_32 (__w.__l[1]); \
128 __r.__l[1] = __bswap_32 (__w.__l[0]); \
129 } \
130 __r.__ll; }))
131 #endif
132
133 #endif /* _BITS_BYTESWAP_H */