ReactOS  0.4.15-dev-3440-g915569a
swab.h
Go to the documentation of this file.
1 #ifndef _LINUX_BYTEORDER_SWAB_H
2 #define _LINUX_BYTEORDER_SWAB_H
3 
4 /*
5  * linux/byteorder/swab.h
6  * Byte-swapping, independently from CPU endianness
7  * swabXX[ps]?(foo)
8  *
9  * Francois-Rene Rideau <fare@tunes.org> 19971205
10  * separated swab functions from cpu_to_XX,
11  * to clean up support for bizarre-endian architectures.
12  *
13  * See asm-i386/byteorder.h and suches for examples of how to provide
14  * architecture-dependent optimized versions
15  *
16  */
17 
18 #include "compiler.h"
19 
20 /* casts are necessary for constants, because we never know how for sure
21  * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
22  */
23 #define ___swab16(x) \
24 ({ \
25  __u16 __x = (x); \
26  ((__u16)( \
27  (((__u16)(__x) & (__u16)0x00ffU) << 8) | \
28  (((__u16)(__x) & (__u16)0xff00U) >> 8) )); \
29 })
30 
31 #define ___swab32(x) \
32 ({ \
33  __u32 __x = (x); \
34  ((__u32)( \
35  (((__u32)(__x) & (__u32)0x000000ffUL) << 24) | \
36  (((__u32)(__x) & (__u32)0x0000ff00UL) << 8) | \
37  (((__u32)(__x) & (__u32)0x00ff0000UL) >> 8) | \
38  (((__u32)(__x) & (__u32)0xff000000UL) >> 24) )); \
39 })
40 
41 #define ___swab64(x) \
42 ({ \
43  __u64 __x = (x); \
44  ((__u64)( \
45  (__u64)(((__u64)(__x) & (__u64)0x00000000000000ffULL) << 56) | \
46  (__u64)(((__u64)(__x) & (__u64)0x000000000000ff00ULL) << 40) | \
47  (__u64)(((__u64)(__x) & (__u64)0x0000000000ff0000ULL) << 24) | \
48  (__u64)(((__u64)(__x) & (__u64)0x00000000ff000000ULL) << 8) | \
49  (__u64)(((__u64)(__x) & (__u64)0x000000ff00000000ULL) >> 8) | \
50  (__u64)(((__u64)(__x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
51  (__u64)(((__u64)(__x) & (__u64)0x00ff000000000000ULL) >> 40) | \
52  (__u64)(((__u64)(__x) & (__u64)0xff00000000000000ULL) >> 56) )); \
53 })
54 
55 #define ___constant_swab16(x) \
56  ((__u16)( \
57  (((__u16)(x) & (__u16)0x00ffU) << 8) | \
58  (((__u16)(x) & (__u16)0xff00U) >> 8) ))
59 #define ___constant_swab32(x) \
60  ((__u32)( \
61  (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
62  (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
63  (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
64  (((__u32)(x) & (__u32)0xff000000UL) >> 24) ))
65 #define ___constant_swab64(x) \
66  ((__u64)( \
67  (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \
68  (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \
69  (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \
70  (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \
71  (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \
72  (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
73  (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \
74  (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) ))
75 
76 /*
77  * provide defaults when no architecture-specific optimization is detected
78  */
79 #ifndef __arch__swab16
80 # define __arch__swab16(x) ({ __u16 __tmp = (x) ; ___swab16(__tmp); })
81 #endif
82 #ifndef __arch__swab32
83 # define __arch__swab32(x) ({ __u32 __tmp = (x) ; ___swab32(__tmp); })
84 #endif
85 #ifndef __arch__swab64
86 # define __arch__swab64(x) ({ __u64 __tmp = (x) ; ___swab64(__tmp); })
87 #endif
88 
89 #ifndef __arch__swab16p
90 # define __arch__swab16p(x) __arch__swab16(*(x))
91 #endif
92 #ifndef __arch__swab32p
93 # define __arch__swab32p(x) __arch__swab32(*(x))
94 #endif
95 #ifndef __arch__swab64p
96 # define __arch__swab64p(x) __arch__swab64(*(x))
97 #endif
98 
99 #ifndef __arch__swab16s
100 # define __arch__swab16s(x) do { *(x) = __arch__swab16p((x)); } while (0)
101 #endif
102 #ifndef __arch__swab32s
103 # define __arch__swab32s(x) do { *(x) = __arch__swab32p((x)); } while (0)
104 #endif
105 #ifndef __arch__swab64s
106 # define __arch__swab64s(x) do { *(x) = __arch__swab64p((x)); } while (0)
107 #endif
108 
109 
110 /*
111  * Allow constant folding
112  */
113 #if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)
114 # define __swab16(x) \
115 (__builtin_constant_p((__u16)(x)) ? \
116  ___swab16((x)) : \
117  __fswab16((x)))
118 # define __swab32(x) \
119 (__builtin_constant_p((__u32)(x)) ? \
120  ___swab32((x)) : \
121  __fswab32((x)))
122 # define __swab64(x) \
123 (__builtin_constant_p((__u64)(x)) ? \
124  ___swab64((x)) : \
125  __fswab64((x)))
126 #else
127 # define __swab16(x) __fswab16(x)
128 # define __swab32(x) __fswab32(x)
129 # define __swab64(x) __fswab64(x)
130 #endif /* OPTIMIZE */
131 
132 
134 {
135  return __arch__swab16(x);
136 }
137 static __inline__ __u16 __swab16p(const __u16 *x)
138 {
139  return __arch__swab16p(x);
140 }
141 static __inline__ void __swab16s(__u16 *addr)
142 {
144 }
145 
147 {
148  return __arch__swab32(x);
149 }
150 static __inline__ __u32 __swab32p(const __u32 *x)
151 {
152  return __arch__swab32p(x);
153 }
154 static __inline__ void __swab32s(__u32 *addr)
155 {
157 }
158 
159 #ifdef __BYTEORDER_HAS_U64__
160 static __inline__ __attribute_const__ __u64 __fswab64(__u64 x)
161 {
162 # ifdef __SWAB_64_THRU_32__
163  __u32 h = x >> 32;
164  __u32 l = x & ((1ULL<<32)-1);
165  return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h)));
166 # else
167  return __arch__swab64(x);
168 # endif
169 }
170 static __inline__ __u64 __swab64p(const __u64 *x)
171 {
172  return __arch__swab64p(x);
173 }
174 static __inline__ void __swab64s(__u64 *addr)
175 {
177 }
178 #endif /* __BYTEORDER_HAS_U64__ */
179 
180 #if defined(__KERNEL__)
181 #define swab16 __swab16
182 #define swab32 __swab32
183 #define swab64 __swab64
184 #define swab16p __swab16p
185 #define swab32p __swab32p
186 #define swab64p __swab64p
187 #define swab16s __swab16s
188 #define swab32s __swab32s
189 #define swab64s __swab64s
190 #endif
191 
192 #endif /* _LINUX_BYTEORDER_SWAB_H */
u32 __u32
Definition: btrfs.h:19
#define __arch__swab64p(x)
Definition: swab.h:96
u16 __u16
Definition: btrfs.h:18
#define __arch__swab32s(x)
Definition: swab.h:103
#define __arch__swab16p(x)
Definition: swab.h:90
static __inline__ __attribute_const__ __u32 __fswab32(__u32 x)
Definition: swab.h:146
GLint GLint GLint GLint GLint x
Definition: gl.h:1548
static __inline__ __attribute_const__ __u16 __fswab16(__u16 x)
Definition: swab.h:133
static __inline__ __u16 __swab16p(const __u16 *x)
Definition: swab.h:137
#define __attribute_const__
Definition: compiler.h:147
GLfloat GLfloat GLfloat GLfloat h
Definition: glext.h:7723
#define __u64
Definition: types.h:17
#define __arch__swab32p(x)
Definition: swab.h:93
#define __swab32(x)
Definition: swab.h:128
#define __arch__swab64(x)
Definition: swab.h:86
u64 __u64
Definition: btrfs.h:20
#define ULL(a, b)
Definition: format_msg.c:27
r l[0]
Definition: byte_order.h:167
#define __arch__swab16s(x)
Definition: swab.h:100
static __inline__ void __swab32s(__u32 *addr)
Definition: swab.h:154
#define __arch__swab32(x)
Definition: swab.h:83
GLenum const GLvoid * addr
Definition: glext.h:9621
#define __arch__swab64s(x)
Definition: swab.h:106
static __inline__ __u32 __swab32p(const __u32 *x)
Definition: swab.h:150
#define __arch__swab16(x)
Definition: swab.h:80
static __inline__ void __swab16s(__u16 *addr)
Definition: swab.h:141