1 /*
2 * Copyright (C) 2016 Andes Technology, Inc.
3 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
4 */
5
6 /* Macros to swap the order of bytes in integer values.
7 Copyright (C) 1997, 1998, 2000, 2002, 2003, 2006, 2007
8 Free Software Foundation, Inc.
9
10 The GNU C Library is free software; you can redistribute it and/or
11 modify it under the terms of the GNU Lesser General Public
12 License as published by the Free Software Foundation; either
13 version 2.1 of the License, or (at your option) any later version.
14
15 The GNU C Library is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
19
20 You should have received a copy of the GNU Lesser General Public
21 License along with the GNU C Library; if not, write to the Free
22 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 02111-1307 USA. */
24
25 #if !defined _BYTESWAP_H && !defined _NETINET_IN_H
26 # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
27 #endif
28
29 #ifndef _BITS_BYTESWAP_H
30 #define _BITS_BYTESWAP_H 1
31
32 /* Swap bytes in 16 bit value. */
33 #define __bswap_constant_16(x) \
34 ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))
35
36 #ifdef __GNUC__
37 # if __GNUC__ >= 2
38 # define __bswap_16(x) \
39 (__extension__ \
40 ({ register unsigned short int __v, __x = (x); \
41 if (__builtin_constant_p (__x)) \
42 __v = __bswap_constant_16 (__x); \
43 else \
44 __asm__ ("wsbh %0, %0\n\t" \
45 : "=r" (__v) \
46 : "0" (__x)); \
47 __v; }))
48 # else
49 /* This is better than nothing. */
50 # define __bswap_16(x) \
51 (__extension__ \
52 ({ register unsigned short int __x = (x); __bswap_constant_16 (__x); }))
53 # endif
54 #else
55 static __inline unsigned short int
__bswap_16(unsigned short int __bsx)56 __bswap_16 (unsigned short int __bsx)
57 {
58 return __bswap_constant_16 (__bsx);
59 }
60 #endif
61
62 /* Swap bytes in 32 bit value. */
63 #define __bswap_constant_32(x) \
64 ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \
65 (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
66
67 #ifdef __GNUC__
68 # if __GNUC__ >= 2
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__ ("wsbh %0, %0\n\t" \
76 "rotri %0, %0, #16\n\t" \
77 : "=r" (__v) \
78 : "0" (__x)); \
79 __v; }))
80 # else
81 # define __bswap_32(x) \
82 (__extension__ \
83 ({ register unsigned int __x = (x); __bswap_constant_32 (__x); }))
84 # endif
85 #else
86 static __inline unsigned int
__bswap_32(unsigned int __bsx)87 __bswap_32 (unsigned int __bsx)
88 {
89 return __bswap_constant_32 (__bsx);
90 }
91 #endif
92
93
94 #if defined __GNUC__ && __GNUC__ >= 2
95 /* Swap bytes in 64 bit value. */
96 #define __bswap_constant_64(x) \
97 ((((x) & 0xff00000000000000ull) >> 56) \
98 | (((x) & 0x00ff000000000000ull) >> 40) \
99 | (((x) & 0x0000ff0000000000ull) >> 24) \
100 | (((x) & 0x000000ff00000000ull) >> 8) \
101 | (((x) & 0x00000000ff000000ull) << 8) \
102 | (((x) & 0x0000000000ff0000ull) << 24) \
103 | (((x) & 0x000000000000ff00ull) << 40) \
104 | (((x) & 0x00000000000000ffull) << 56))
105
106 # define __bswap_64(x) \
107 (__extension__ \
108 ({ union { __extension__ unsigned long long int __ll; \
109 unsigned long int __l[2]; } __w, __r; \
110 if (__builtin_constant_p (x)) \
111 __r.__ll = __bswap_constant_64 (x); \
112 else \
113 { \
114 __w.__ll = (x); \
115 __r.__l[0] = __bswap_32 (__w.__l[1]); \
116 __r.__l[1] = __bswap_32 (__w.__l[0]); \
117 } \
118 __r.__ll; }))
119 #endif
120
121 #endif /* _BITS_BYTESWAP_H */
122