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1522c368 | 1 | /* Macros to swap the order of bytes in integer values. |
32c075e1 JJ |
2 | Copyright (C) 1997, 1998, 2000, 2002, 2003, 2006, 2007 |
3 | Free Software Foundation, Inc. | |
1522c368 UD |
4 | This file is part of the GNU C Library. |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
1522c368 UD |
10 | |
11 | The GNU C Library 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 GNU | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
1522c368 | 15 | |
41bdb6e2 AJ |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, write to the Free | |
18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
19 | 02111-1307 USA. */ | |
1522c368 | 20 | |
f4017d20 UD |
21 | #if !defined _BYTESWAP_H && !defined _NETINET_IN_H |
22 | # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead." | |
23 | #endif | |
1522c368 | 24 | |
5c26fecb AJ |
25 | #ifndef _BITS_BYTESWAP_H |
26 | #define _BITS_BYTESWAP_H 1 | |
27 | ||
1522c368 UD |
28 | /* Swap bytes in 16 bit value. */ |
29 | #define __bswap_constant_16(x) \ | |
30 | ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8)) | |
31 | ||
b5facfda UD |
32 | #ifdef __GNUC__ |
33 | # if __GNUC__ >= 2 | |
34 | # define __bswap_16(x) \ | |
7782d0bf | 35 | (__extension__ \ |
7a8bdff0 RM |
36 | ({ register unsigned short int __v, __x = (x); \ |
37 | if (__builtin_constant_p (__x)) \ | |
38 | __v = __bswap_constant_16 (__x); \ | |
7782d0bf | 39 | else \ |
7a8bdff0 RM |
40 | __asm__ ("rorw $8, %w0" \ |
41 | : "=r" (__v) \ | |
42 | : "0" (__x) \ | |
43 | : "cc"); \ | |
7782d0bf | 44 | __v; })) |
b5facfda | 45 | # else |
1522c368 | 46 | /* This is better than nothing. */ |
b5facfda | 47 | # define __bswap_16(x) \ |
7a8bdff0 RM |
48 | (__extension__ \ |
49 | ({ register unsigned short int __x = (x); __bswap_constant_16 (__x); })) | |
b5facfda UD |
50 | # endif |
51 | #else | |
52 | static __inline unsigned short int | |
53 | __bswap_16 (unsigned short int __bsx) | |
54 | { | |
55 | return __bswap_constant_16 (__bsx); | |
56 | } | |
1522c368 UD |
57 | #endif |
58 | ||
1522c368 UD |
59 | /* Swap bytes in 32 bit value. */ |
60 | #define __bswap_constant_32(x) \ | |
61 | ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \ | |
62 | (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24)) | |
63 | ||
b5facfda UD |
64 | #ifdef __GNUC__ |
65 | # if __GNUC__ >= 2 | |
1522c368 UD |
66 | /* To swap the bytes in a word the i486 processors and up provide the |
67 | `bswap' opcode. On i386 we have to use three instructions. */ | |
2236d6e1 | 68 | # if !defined __i486__ && !defined __pentium__ && !defined __pentiumpro__ \ |
542a6f62 | 69 | && !defined __pentium4__ && !defined __k8__ && !defined __athlon__ \ |
32c075e1 JJ |
70 | && !defined __k6__ && !defined __nocona__ && !defined __core2__ \ |
71 | && !defined __geode__ && !defined __amdfam10__ | |
b5facfda | 72 | # define __bswap_32(x) \ |
7782d0bf | 73 | (__extension__ \ |
7a8bdff0 RM |
74 | ({ register unsigned int __v, __x = (x); \ |
75 | if (__builtin_constant_p (__x)) \ | |
76 | __v = __bswap_constant_32 (__x); \ | |
7782d0bf | 77 | else \ |
7a8bdff0 RM |
78 | __asm__ ("rorw $8, %w0;" \ |
79 | "rorl $16, %0;" \ | |
80 | "rorw $8, %w0" \ | |
81 | : "=r" (__v) \ | |
82 | : "0" (__x) \ | |
83 | : "cc"); \ | |
7782d0bf | 84 | __v; })) |
b5facfda UD |
85 | # else |
86 | # define __bswap_32(x) \ | |
7782d0bf | 87 | (__extension__ \ |
7a8bdff0 RM |
88 | ({ register unsigned int __v, __x = (x); \ |
89 | if (__builtin_constant_p (__x)) \ | |
90 | __v = __bswap_constant_32 (__x); \ | |
7782d0bf | 91 | else \ |
7a8bdff0 | 92 | __asm__ ("bswap %0" : "=r" (__v) : "0" (__x)); \ |
7782d0bf | 93 | __v; })) |
b5facfda UD |
94 | # endif |
95 | # else | |
96 | # define __bswap_32(x) \ | |
7a8bdff0 RM |
97 | (__extension__ \ |
98 | ({ register unsigned int __x = (x); __bswap_constant_32 (__x); })) | |
b5facfda UD |
99 | # endif |
100 | #else | |
101 | static __inline unsigned int | |
102 | __bswap_32 (unsigned int __bsx) | |
103 | { | |
104 | return __bswap_constant_32 (__bsx); | |
105 | } | |
1522c368 UD |
106 | #endif |
107 | ||
108 | ||
109 | #if defined __GNUC__ && __GNUC__ >= 2 | |
110 | /* Swap bytes in 64 bit value. */ | |
3d7f417b UD |
111 | #define __bswap_constant_64(x) \ |
112 | ((((x) & 0xff00000000000000ull) >> 56) \ | |
113 | | (((x) & 0x00ff000000000000ull) >> 40) \ | |
114 | | (((x) & 0x0000ff0000000000ull) >> 24) \ | |
115 | | (((x) & 0x000000ff00000000ull) >> 8) \ | |
116 | | (((x) & 0x00000000ff000000ull) << 8) \ | |
117 | | (((x) & 0x0000000000ff0000ull) << 24) \ | |
118 | | (((x) & 0x000000000000ff00ull) << 40) \ | |
119 | | (((x) & 0x00000000000000ffull) << 56)) | |
120 | ||
1522c368 | 121 | # define __bswap_64(x) \ |
7782d0bf UD |
122 | (__extension__ \ |
123 | ({ union { __extension__ unsigned long long int __ll; \ | |
124 | unsigned long int __l[2]; } __w, __r; \ | |
70a8ca6d UD |
125 | if (__builtin_constant_p (x)) \ |
126 | __r.__ll = __bswap_constant_64 (x); \ | |
3d7f417b UD |
127 | else \ |
128 | { \ | |
70a8ca6d | 129 | __w.__ll = (x); \ |
3d7f417b UD |
130 | __r.__l[0] = __bswap_32 (__w.__l[1]); \ |
131 | __r.__l[1] = __bswap_32 (__w.__l[0]); \ | |
132 | } \ | |
7782d0bf | 133 | __r.__ll; })) |
1522c368 | 134 | #endif |
5c26fecb AJ |
135 | |
136 | #endif /* _BITS_BYTESWAP_H */ |