1*53ee8cc1Swenshuai.xi /* Macros to swap the order of bytes in integer values.
2*53ee8cc1Swenshuai.xi Copyright (C) 1997,1998,2000,2001,2002,2005 Free Software Foundation, Inc.
3*53ee8cc1Swenshuai.xi This file is part of the GNU C Library.
4*53ee8cc1Swenshuai.xi
5*53ee8cc1Swenshuai.xi The GNU C Library is free software; you can redistribute it and/or
6*53ee8cc1Swenshuai.xi modify it under the terms of the GNU Lesser General Public
7*53ee8cc1Swenshuai.xi License as published by the Free Software Foundation; either
8*53ee8cc1Swenshuai.xi version 2.1 of the License, or (at your option) any later version.
9*53ee8cc1Swenshuai.xi
10*53ee8cc1Swenshuai.xi The GNU C Library is distributed in the hope that it will be useful,
11*53ee8cc1Swenshuai.xi but WITHOUT ANY WARRANTY; without even the implied warranty of
12*53ee8cc1Swenshuai.xi MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13*53ee8cc1Swenshuai.xi Lesser General Public License for more details.
14*53ee8cc1Swenshuai.xi
15*53ee8cc1Swenshuai.xi You should have received a copy of the GNU Lesser General Public
16*53ee8cc1Swenshuai.xi License along with the GNU C Library; if not, write to the Free
17*53ee8cc1Swenshuai.xi Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18*53ee8cc1Swenshuai.xi 02111-1307 USA. */
19*53ee8cc1Swenshuai.xi
20*53ee8cc1Swenshuai.xi #if !defined _BYTESWAP_H && !defined _NETINET_IN_H
21*53ee8cc1Swenshuai.xi # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
22*53ee8cc1Swenshuai.xi #endif
23*53ee8cc1Swenshuai.xi
24*53ee8cc1Swenshuai.xi #ifndef _BITS_BYTESWAP_H
25*53ee8cc1Swenshuai.xi #define _BITS_BYTESWAP_H 1
26*53ee8cc1Swenshuai.xi
27*53ee8cc1Swenshuai.xi /* Swap bytes in 16 bit value. */
28*53ee8cc1Swenshuai.xi #define __bswap_constant_16(x) \
29*53ee8cc1Swenshuai.xi ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))
30*53ee8cc1Swenshuai.xi
31*53ee8cc1Swenshuai.xi #ifdef __GNUC__
32*53ee8cc1Swenshuai.xi # define __bswap_16(x) \
33*53ee8cc1Swenshuai.xi (__extension__ \
34*53ee8cc1Swenshuai.xi ({ unsigned short int __bsx = (x); __bswap_constant_16 (__bsx); }))
35*53ee8cc1Swenshuai.xi #else
36*53ee8cc1Swenshuai.xi static __inline unsigned short int
__bswap_16(unsigned short int __bsx)37*53ee8cc1Swenshuai.xi __bswap_16 (unsigned short int __bsx)
38*53ee8cc1Swenshuai.xi {
39*53ee8cc1Swenshuai.xi return __bswap_constant_16 (__bsx);
40*53ee8cc1Swenshuai.xi }
41*53ee8cc1Swenshuai.xi #endif
42*53ee8cc1Swenshuai.xi
43*53ee8cc1Swenshuai.xi /* Swap bytes in 32 bit value. */
44*53ee8cc1Swenshuai.xi #define __bswap_constant_32(x) \
45*53ee8cc1Swenshuai.xi ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \
46*53ee8cc1Swenshuai.xi (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24))
47*53ee8cc1Swenshuai.xi
48*53ee8cc1Swenshuai.xi #ifdef __GNUC__
49*53ee8cc1Swenshuai.xi # define __bswap_32(x) \
50*53ee8cc1Swenshuai.xi (__extension__ \
51*53ee8cc1Swenshuai.xi ({ register unsigned int __bsx = (x); __bswap_constant_32 (__bsx); }))
52*53ee8cc1Swenshuai.xi #else
53*53ee8cc1Swenshuai.xi static __inline unsigned int
__bswap_32(unsigned int __bsx)54*53ee8cc1Swenshuai.xi __bswap_32 (unsigned int __bsx)
55*53ee8cc1Swenshuai.xi {
56*53ee8cc1Swenshuai.xi return __bswap_constant_32 (__bsx);
57*53ee8cc1Swenshuai.xi }
58*53ee8cc1Swenshuai.xi #endif
59*53ee8cc1Swenshuai.xi
60*53ee8cc1Swenshuai.xi #if defined __GNUC__ && __GNUC__ >= 2
61*53ee8cc1Swenshuai.xi /* Swap bytes in 64 bit value. */
62*53ee8cc1Swenshuai.xi # define __bswap_constant_64(x) \
63*53ee8cc1Swenshuai.xi ((((x) & 0xff00000000000000ull) >> 56) \
64*53ee8cc1Swenshuai.xi | (((x) & 0x00ff000000000000ull) >> 40) \
65*53ee8cc1Swenshuai.xi | (((x) & 0x0000ff0000000000ull) >> 24) \
66*53ee8cc1Swenshuai.xi | (((x) & 0x000000ff00000000ull) >> 8) \
67*53ee8cc1Swenshuai.xi | (((x) & 0x00000000ff000000ull) << 8) \
68*53ee8cc1Swenshuai.xi | (((x) & 0x0000000000ff0000ull) << 24) \
69*53ee8cc1Swenshuai.xi | (((x) & 0x000000000000ff00ull) << 40) \
70*53ee8cc1Swenshuai.xi | (((x) & 0x00000000000000ffull) << 56))
71*53ee8cc1Swenshuai.xi
72*53ee8cc1Swenshuai.xi # define __bswap_64(x) \
73*53ee8cc1Swenshuai.xi (__extension__ \
74*53ee8cc1Swenshuai.xi ({ union { __extension__ unsigned long long int __ll; \
75*53ee8cc1Swenshuai.xi unsigned int __l[2]; } __w, __r; \
76*53ee8cc1Swenshuai.xi if (__builtin_constant_p (x)) \
77*53ee8cc1Swenshuai.xi __r.__ll = __bswap_constant_64 (x); \
78*53ee8cc1Swenshuai.xi else \
79*53ee8cc1Swenshuai.xi { \
80*53ee8cc1Swenshuai.xi __w.__ll = (x); \
81*53ee8cc1Swenshuai.xi __r.__l[0] = __bswap_32 (__w.__l[1]); \
82*53ee8cc1Swenshuai.xi __r.__l[1] = __bswap_32 (__w.__l[0]); \
83*53ee8cc1Swenshuai.xi } \
84*53ee8cc1Swenshuai.xi __r.__ll; }))
85*53ee8cc1Swenshuai.xi #endif
86*53ee8cc1Swenshuai.xi
87*53ee8cc1Swenshuai.xi #endif /* _BITS_BYTESWAP_H */
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