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Annotation of embedaddon/bird/lib/unaligned.h, revision 1.1

1.1     ! misho       1: /*
        !             2:  *     Unaligned Data Accesses -- Generic Version, Network Order
        !             3:  *
        !             4:  *     (c) 2000 Martin Mares <mj@ucw.cz>
        !             5:  *
        !             6:  *     Can be freely distributed and used under the terms of the GNU GPL.
        !             7:  */
        !             8: 
        !             9: #ifndef _BIRD_UNALIGNED_H_
        !            10: #define _BIRD_UNALIGNED_H_
        !            11: 
        !            12: /*
        !            13:  *  We don't do any clever tricks with unaligned accesses since it's
        !            14:  *  virtually impossible to figure out what alignment does the CPU want
        !            15:  *  (unaligned accesses can be emulated by the OS which makes them work,
        !            16:  *  but unusably slow). We use memcpy and hope GCC will optimize it out
        !            17:  *  if possible.
        !            18:  */
        !            19: 
        !            20: #include "lib/string.h"
        !            21: 
        !            22: static inline u16
        !            23: get_u16(const void *p)
        !            24: {
        !            25:   u16 x;
        !            26:   memcpy(&x, p, 2);
        !            27:   return ntohs(x);
        !            28: }
        !            29: 
        !            30: static inline u32
        !            31: get_u32(const void *p)
        !            32: {
        !            33:   u32 x;
        !            34:   memcpy(&x, p, 4);
        !            35:   return ntohl(x);
        !            36: }
        !            37: 
        !            38: static inline u64
        !            39: get_u64(const void *p)
        !            40: {
        !            41:   u32 xh, xl;
        !            42:   memcpy(&xh, p, 4);
        !            43:   memcpy(&xl, p+4, 4);
        !            44:   return (((u64) ntohl(xh)) << 32) | ntohl(xl);
        !            45: }
        !            46: 
        !            47: static inline void
        !            48: put_u16(void *p, u16 x)
        !            49: {
        !            50:   x = htons(x);
        !            51:   memcpy(p, &x, 2);
        !            52: }
        !            53: 
        !            54: static inline void
        !            55: put_u32(void *p, u32 x)
        !            56: {
        !            57:   x = htonl(x);
        !            58:   memcpy(p, &x, 4);
        !            59: }
        !            60: 
        !            61: static inline void
        !            62: put_u64(void *p, u64 x)
        !            63: {
        !            64:   u32 xh, xl;
        !            65:   xh = htonl(x >> 32);
        !            66:   xl = htonl((u32) x);
        !            67:   memcpy(p, &xh, 4);
        !            68:   memcpy(p+4, &xl, 4);
        !            69: }
        !            70: 
        !            71: #endif