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1#ifndef _LINUX_BYTEORDER_SWABB_H
2#define _LINUX_BYTEORDER_SWABB_H
3
4/*
5 * linux/byteorder/swabb.h
6 * SWAp Bytes Bizarrely
7 * swaHHXX[ps]?(foo)
8 *
9 * Support for obNUXIous pdp-endian and other bizarre architectures.
10 * Will Linux ever run on such ancient beasts? if not, this file
11 * will be but a programming pearl. Still, it's a reminder that we
12 * shouldn't be making too many assumptions when trying to be portable.
13 *
14 */
15
16/*
17 * Meaning of the names I chose (vaxlinux people feel free to correct them):
18 * swahw32 swap 16-bit half-words in a 32-bit word
19 * swahb32 swap 8-bit halves of each 16-bit half-word in a 32-bit word
20 *
21 * No 64-bit support yet. I don't know NUXI conventions for long longs.
22 * I guarantee it will be a mess when it's there, though :->
23 * It will be even worse if there are conflicting 64-bit conventions.
24 * Hopefully, no one ever used 64-bit objects on NUXI machines.
25 *
26 */
27
28#include <linux/types.h>
29
30#define ___swahw32(x) \
31({ \
32 __u32 __x = (x); \
33 ((__u32)( \
34 (((__u32)(__x) & (__u32)0x0000ffffUL) << 16) | \
35 (((__u32)(__x) & (__u32)0xffff0000UL) >> 16) )); \
36})
37#define ___swahb32(x) \
38({ \
39 __u32 __x = (x); \
40 ((__u32)( \
41 (((__u32)(__x) & (__u32)0x00ff00ffUL) << 8) | \
42 (((__u32)(__x) & (__u32)0xff00ff00UL) >> 8) )); \
43})
44
45#define ___constant_swahw32(x) \
46 ((__u32)( \
47 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \
48 (((__u32)(x) & (__u32)0xffff0000UL) >> 16) ))
49#define ___constant_swahb32(x) \
50 ((__u32)( \
51 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \
52 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8) ))
53
54/*
55 * provide defaults when no architecture-specific optimization is detected
56 */
57#ifndef __arch__swahw32
58# define __arch__swahw32(x) ___swahw32(x)
59#endif
60#ifndef __arch__swahb32
61# define __arch__swahb32(x) ___swahb32(x)
62#endif
63
64#ifndef __arch__swahw32p
65# define __arch__swahw32p(x) __swahw32(*(x))
66#endif
67#ifndef __arch__swahb32p
68# define __arch__swahb32p(x) __swahb32(*(x))
69#endif
70
71#ifndef __arch__swahw32s
72# define __arch__swahw32s(x) do { *(x) = __swahw32p((x)); } while (0)
73#endif
74#ifndef __arch__swahb32s
75# define __arch__swahb32s(x) do { *(x) = __swahb32p((x)); } while (0)
76#endif
77
78
79/*
80 * Allow constant folding
81 */
82#define __swahw32(x) \
83(__builtin_constant_p((__u32)(x)) ? \
84 ___swahw32((x)) : \
85 __fswahw32((x)))
86#define __swahb32(x) \
87(__builtin_constant_p((__u32)(x)) ? \
88 ___swahb32((x)) : \
89 __fswahb32((x)))
90
91
92static inline __u32 __fswahw32(__u32 x)
93{
94 return __arch__swahw32(x);
95}
96
97static inline __u32 __swahw32p(__u32 *x)
98{
99 return __arch__swahw32p(x);
100}
101
102static inline void __swahw32s(__u32 *addr)
103{
104 __arch__swahw32s(addr);
105}
106
107static inline __u32 __fswahb32(__u32 x)
108{
109 return __arch__swahb32(x);
110}
111
112static inline __u32 __swahb32p(__u32 *x)
113{
114 return __arch__swahb32p(x);
115}
116
117static inline void __swahb32s(__u32 *addr)
118{
119 __arch__swahb32s(addr);
120}
121
122#ifdef __BYTEORDER_HAS_U64__
123/*
124 * Not supported yet
125 */
126#endif /* __BYTEORDER_HAS_U64__ */
127
128#define swahw32 __swahw32
129#define swahb32 __swahb32
130#define swahw32p __swahw32p
131#define swahb32p __swahb32p
132#define swahw32s __swahw32s
133#define swahb32s __swahb32s
134
135#endif /* _LINUX_BYTEORDER_SWABB_H */