[thirdparty/bird.git] / lib / unaligned.h

/*
 *	Unaligned Data Accesses -- Generic Version, Network Order
 *
 *	(c) 2000 Martin Mares <mj@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#ifndef _BIRD_UNALIGNED_H_
#define _BIRD_UNALIGNED_H_

/*
 *  We don't do any clever tricks with unaligned accesses since it's
 *  virtually impossible to figure out what alignment does the CPU want
 *  (unaligned accesses can be emulated by the OS which makes them work,
 *  but unusably slow). We use memcpy and hope GCC will optimize it out
 *  if possible.
 */

#include "lib/string.h"

static inline u16
get_u16(void *p)
{
  u16 x;
  memcpy(&x, p, 2);
  return ntohs(x);
}

static inline u32
get_u32(void *p)
{
  u32 x;
  memcpy(&x, p, 4);
  return ntohl(x);
}

static inline void
put_u16(void *p, u16 x)
{
  x = htons(x);
  memcpy(p, &x, 2);
}

static inline void
put_u32(void *p, u32 x)
{
  x = htonl(x);
  memcpy(p, &x, 4);
}

#endif
Commit	Line	Data
58ef912c	1	/*
a8f944cb	2	* Unaligned Data Accesses -- Generic Version, Network Order
58ef912c	3	*
a8f944cb	4	* (c) 2000 Martin Mares <mj@ucw.cz>
58ef912c MM	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
a8f944cb MM	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
221135d6	20	#include "lib/string.h"
b1487ee9	21
b1487ee9	22	static inline u16
a8f944cb	23	get_u16(void *p)
b1487ee9 MM	24	{
b1487ee9 MM	25	u16 x;
a8f944cb MM	26	memcpy(&x, p, 2);
a8f944cb MM	27	return ntohs(x);
b1487ee9	28	}
b1487ee9	29
b1487ee9	30	static inline u32
a8f944cb	31	get_u32(void *p)
b1487ee9 MM	32	{
b1487ee9 MM	33	u32 x;
a8f944cb MM	34	memcpy(&x, p, 4);
	35	return ntohl(x);
	36	}
b1487ee9	37
a8f944cb MM	38	static inline void
	39	put_u16(void *p, u16 x)
	40	{
	41	x = htons(x);
	42	memcpy(p, &x, 2);
	43	}
	44
	45	static inline void
	46	put_u32(void *p, u32 x)
	47	{
	48	x = htonl(x);
	49	memcpy(p, &x, 4);
b1487ee9	50	}
b1487ee9	51
58ef912c	52	#endif