initial commit with v2.6.9
[linux-2.6.9-moxart.git] / include / linux / byteorder / swabb.h
blobd28d9a804d3bc0c92e2dcde511e430b4c7a681ef
1 #ifndef _LINUX_BYTEORDER_SWABB_H
2 #define _LINUX_BYTEORDER_SWABB_H
4 /*
5 * linux/byteorder/swabb.h
6 * SWAp Bytes Bizarrely
7 * swaHHXX[ps]?(foo)
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.
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
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.
28 #define ___swahw32(x) \
29 ({ \
30 __u32 __x = (x); \
31 ((__u32)( \
32 (((__u32)(__x) & (__u32)0x0000ffffUL) << 16) | \
33 (((__u32)(__x) & (__u32)0xffff0000UL) >> 16) )); \
35 #define ___swahb32(x) \
36 ({ \
37 __u32 __x = (x); \
38 ((__u32)( \
39 (((__u32)(__x) & (__u32)0x00ff00ffUL) << 8) | \
40 (((__u32)(__x) & (__u32)0xff00ff00UL) >> 8) )); \
43 #define ___constant_swahw32(x) \
44 ((__u32)( \
45 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \
46 (((__u32)(x) & (__u32)0xffff0000UL) >> 16) ))
47 #define ___constant_swahb32(x) \
48 ((__u32)( \
49 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \
50 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8) ))
53 * provide defaults when no architecture-specific optimization is detected
55 #ifndef __arch__swahw32
56 # define __arch__swahw32(x) ___swahw32(x)
57 #endif
58 #ifndef __arch__swahb32
59 # define __arch__swahb32(x) ___swahb32(x)
60 #endif
62 #ifndef __arch__swahw32p
63 # define __arch__swahw32p(x) __swahw32(*(x))
64 #endif
65 #ifndef __arch__swahb32p
66 # define __arch__swahb32p(x) __swahb32(*(x))
67 #endif
69 #ifndef __arch__swahw32s
70 # define __arch__swahw32s(x) do { *(x) = __swahw32p((x)); } while (0)
71 #endif
72 #ifndef __arch__swahb32s
73 # define __arch__swahb32s(x) do { *(x) = __swahb32p((x)); } while (0)
74 #endif
78 * Allow constant folding
80 #if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)
81 # define __swahw32(x) \
82 (__builtin_constant_p((__u32)(x)) ? \
83 ___swahw32((x)) : \
84 __fswahw32((x)))
85 # define __swahb32(x) \
86 (__builtin_constant_p((__u32)(x)) ? \
87 ___swahb32((x)) : \
88 __fswahb32((x)))
89 #else
90 # define __swahw32(x) __fswahw32(x)
91 # define __swahb32(x) __fswahb32(x)
92 #endif /* OPTIMIZE */
95 static __inline__ __const__ __u32 __fswahw32(__u32 x)
97 return __arch__swahw32(x);
99 static __inline__ __u32 __swahw32p(__u32 *x)
101 return __arch__swahw32p(x);
103 static __inline__ void __swahw32s(__u32 *addr)
105 __arch__swahw32s(addr);
109 static __inline__ __const__ __u32 __fswahb32(__u32 x)
111 return __arch__swahb32(x);
113 static __inline__ __u32 __swahb32p(__u32 *x)
115 return __arch__swahb32p(x);
117 static __inline__ void __swahb32s(__u32 *addr)
119 __arch__swahb32s(addr);
122 #ifdef __BYTEORDER_HAS_U64__
124 * Not supported yet
126 #endif /* __BYTEORDER_HAS_U64__ */
128 #if defined(__KERNEL__)
129 #define swahw32 __swahw32
130 #define swahb32 __swahb32
131 #define swahw32p __swahw32p
132 #define swahb32p __swahb32p
133 #define swahw32s __swahw32s
134 #define swahb32s __swahb32s
135 #endif
137 #endif /* _LINUX_BYTEORDER_SWABB_H */