Return to byteorder.h CVS log

Up to [GCC 2.x] / gcc

Annotation of gcc/byteorder.h, revision 1.1

1.1     ! root        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 ([email protected]).
        !             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 (__ns32k__) || defined (__vax__) || defined (__spur__) || defined (__arm__)
        !            66: 
        !            67: /* For other little-endian machines, using C code is just as efficient as
        !            68:    using assembly code.  */
        !            69: 
        !            70: /* Convert a host long to a network long.  */
        !            71: 
        !            72: __STATIC __inline__ unsigned long
        !            73: htonl (__arg)
        !            74:      unsigned long __arg;
        !            75: {
        !            76:   register unsigned long __result;
        !            77: 
        !            78:   __result = (__arg >> 24) & 0x000000ff;
        !            79:   __result |= (__arg >> 8) & 0x0000ff00;
        !            80:   __result |= (__arg << 8) & 0x00ff0000;
        !            81:   __result |= (__arg << 24) & 0xff000000;
        !            82:   return __result;
        !            83: }
        !            84: 
        !            85: /* Convert a host short to a network short.  */
        !            86: 
        !            87: __STATIC __inline__ unsigned short
        !            88: htons (__arg)
        !            89:      unsigned short __arg;
        !            90: {
        !            91:   register unsigned short __result;
        !            92: 
        !            93:   __result = (__arg << 8) & 0xff00;
        !            94:   __result |= (__arg >> 8) & 0x00ff;
        !            95:   return __result;
        !            96: }
        !            97: 
        !            98: #else /* must be a big-endian machine */
        !            99: 
        !           100: /* Convert a host long to a network long.  */
        !           101: 
        !           102: __STATIC __inline__ unsigned long
        !           103: htonl (__arg)
        !           104:      unsigned long __arg;
        !           105: {
        !           106:   return __arg;
        !           107: }
        !           108: 
        !           109: /* Convert a host short to a network short.  */
        !           110: 
        !           111: __STATIC __inline__ unsigned short
        !           112: htons (__arg)
        !           113:      unsigned short __arg;
        !           114: {
        !           115:   return __arg;
        !           116: }
        !           117: 
        !           118: #endif /* big-endian */
        !           119: 
        !           120: /* Convert a network long to a host long.  */
        !           121: 
        !           122: __STATIC __inline__ unsigned long
        !           123: ntohl (__arg)
        !           124:      unsigned long __arg;
        !           125: {
        !           126:   return htonl (__arg);
        !           127: }
        !           128: 
        !           129: /* Convert a network short to a host short.  */
        !           130: 
        !           131: __STATIC __inline__ unsigned short
        !           132: ntohs (__arg)
        !           133:      unsigned int __arg;
        !           134: {
        !           135:   return htons (__arg);
        !           136: }
        !           137: 
        !           138: 
        !           139: #undef __STATIC
        !           140: 
        !           141: #endif /* !defined (_SYS_BYTEORDER_H) */

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.