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