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| Commit | Line | Data |
|---|---|---|
| 764fe7f1 C |
1 | #ifndef _SYS_BYTEORDER_H |
| 2 | #define _SYS_BYTEORDER_H | |
| 3 | ||
| 4 | /* Functions to convert `short' and `long' quantities from host byte order | |
| 5 | to (internet) network byte order (i.e. big-endian). | |
| 6 | ||
| 7 | Written by Ron Guilmette (rfg@ncd.com). | |
| 8 | ||
| 9 | This isn't actually used by GCC. It is installed by fixinc.svr4. | |
| 10 | ||
| 11 | For big-endian machines these functions are essentially no-ops. | |
| 12 | ||
| 13 | For little-endian machines, we define the functions using specialized | |
| 14 | asm sequences in cases where doing so yields better code (e.g. i386). */ | |
| 15 | ||
| 16 | #if !defined (__GNUC__) && !defined (__GNUG__) | |
| 17 | #error You lose! This file is only useful with GNU compilers. | |
| 18 | #endif | |
| 19 | ||
| 20 | #ifdef __GNUC__ | |
| 21 | #define __STATIC static | |
| 22 | #else | |
| 23 | #define __STATIC | |
| 24 | #endif | |
| 25 | ||
| 26 | #ifdef __STDC__ | |
| 27 | __STATIC __inline__ unsigned long htonl (unsigned long); | |
| 28 | __STATIC __inline__ unsigned short htons (unsigned int); | |
| 29 | __STATIC __inline__ unsigned long ntohl (unsigned long); | |
| 30 | __STATIC __inline__ unsigned short ntohs (unsigned int); | |
| 31 | #endif /* defined (__STDC__) */ | |
| 32 | ||
| 33 | #if defined (__i386__) | |
| 34 | ||
| 35 | /* Convert a host long to a network long. */ | |
| 36 | ||
| 37 | __STATIC __inline__ unsigned long | |
| 38 | htonl (__arg) | |
| 39 | unsigned long __arg; | |
| 40 | { | |
| 41 | register unsigned long __result __asm__ ("%eax"); | |
| 42 | ||
| 43 | __result = __arg; | |
| 44 | __asm__ ("xchgb %%ah, %%al\n\ | |
| 45 | rorl $16, %%eax\n\ | |
| 46 | xchgb %%ah, %%al\n\ | |
| 47 | clc" : "=r" (__result) : "0" (__result)); | |
| 48 | return __result; | |
| 49 | } | |
| 50 | ||
| 51 | /* Convert a host short to a network short. */ | |
| 52 | ||
| 53 | __STATIC __inline__ unsigned short | |
| 54 | htons (__arg) | |
| 55 | unsigned int __arg; | |
| 56 | { | |
| 57 | register unsigned short __result __asm__ ("%eax"); | |
| 58 | ||
| 59 | __result = __arg; | |
| 60 | __asm__ ("xchgb %%ah, %%al\n\ | |
| 61 | clc" : "=r" (__result) : "0" (__result)); | |
| 62 | return __result; | |
| 63 | } | |
| 64 | ||
| 65 | #elif ((defined (__i860__) && !defined (__i860_big_endian__)) \ | |
| 66 | || defined (__ns32k__) || defined (__vax__) \ | |
| 67 | || defined (__spur__) || defined (__arm__)) | |
| 68 | ||
| 69 | /* For other little-endian machines, using C code is just as efficient as | |
| 70 | using assembly code. */ | |
| 71 | ||
| 72 | /* Convert a host long to a network long. */ | |
| 73 | ||
| 74 | __STATIC __inline__ unsigned long | |
| 75 | htonl (__arg) | |
| 76 | unsigned long __arg; | |
| 77 | { | |
| 78 | register unsigned long __result; | |
| 79 | ||
| 80 | __result = (__arg >> 24) & 0x000000ff; | |
| 81 | __result |= (__arg >> 8) & 0x0000ff00; | |
| 82 | __result |= (__arg << 8) & 0x00ff0000; | |
| 83 | __result |= (__arg << 24) & 0xff000000; | |
| 84 | return __result; | |
| 85 | } | |
| 86 | ||
| 87 | /* Convert a host short to a network short. */ | |
| 88 | ||
| 89 | __STATIC __inline__ unsigned short | |
| 90 | htons (__arg) | |
| 91 | unsigned int __arg; | |
| 92 | { | |
| 93 | register unsigned short __result; | |
| 94 | ||
| 95 | __result = (__arg << 8) & 0xff00; | |
| 96 | __result |= (__arg >> 8) & 0x00ff; | |
| 97 | return __result; | |
| 98 | } | |
| 99 | ||
| 100 | #else /* must be a big-endian machine */ | |
| 101 | ||
| 102 | /* Convert a host long to a network long. */ | |
| 103 | ||
| 104 | __STATIC __inline__ unsigned long | |
| 105 | htonl (__arg) | |
| 106 | unsigned long __arg; | |
| 107 | { | |
| 108 | return __arg; | |
| 109 | } | |
| 110 | ||
| 111 | /* Convert a host short to a network short. */ | |
| 112 | ||
| 113 | __STATIC __inline__ unsigned short | |
| 114 | htons (__arg) | |
| 115 | unsigned int __arg; | |
| 116 | { | |
| 117 | return __arg; | |
| 118 | } | |
| 119 | ||
| 120 | #endif /* big-endian */ | |
| 121 | ||
| 122 | /* Convert a network long to a host long. */ | |
| 123 | ||
| 124 | __STATIC __inline__ unsigned long | |
| 125 | ntohl (__arg) | |
| 126 | unsigned long __arg; | |
| 127 | { | |
| 128 | return htonl (__arg); | |
| 129 | } | |
| 130 | ||
| 131 | /* Convert a network short to a host short. */ | |
| 132 | ||
| 133 | __STATIC __inline__ unsigned short | |
| 134 | ntohs (__arg) | |
| 135 | unsigned int __arg; | |
| 136 | { | |
| 137 | return htons (__arg); | |
| 138 | } | |
| 139 | ||
| 140 | ||
| 141 | #undef __STATIC | |
| 142 | ||
| 143 | #endif /* !defined (_SYS_BYTEORDER_H) */ |