[rsync/rsync.git] / byteorder.h

/*
 * Simple byteorder handling.
 *
 * Copyright (C) 1992-1995 Andrew Tridgell
 * Copyright (C) 2007-2008 Wayne Davison
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, visit the http://fsf.org website.
 */

#undef CAREFUL_ALIGNMENT
#undef AVOID_BYTEORDER_INLINE

/* We know that the x86 can handle misalignment and has the same
 * byte order (LSB-first) as the 32-bit numbers we transmit. */
#ifdef __i386__
#define CAREFUL_ALIGNMENT 0
#endif

#ifndef CAREFUL_ALIGNMENT
#define CAREFUL_ALIGNMENT 1
#endif

#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
#define UVAL(buf,pos) ((uint32)CVAL(buf,pos))

#if CAREFUL_ALIGNMENT

#define PVAL(buf,pos) (UVAL(buf,pos)|UVAL(buf,(pos)+1)<<8)
#define IVAL(buf,pos) (PVAL(buf,pos)|PVAL(buf,(pos)+2)<<16)
#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
#define SIVALX(buf,pos,val) (SSVALX(buf,pos,val&0xFFFF),SSVALX(buf,pos+2,val>>16))
#define SIVAL(buf,pos,val) SIVALX((buf),(pos),((uint32)(val)))

#define IVALu(buf,pos) IVAL(buf,pos)
#define SIVALu(buf,pos,val) SIVAL(buf,pos,val)

#else /* !CAREFUL_ALIGNMENT */

/* This handles things for architectures like the 386 that can handle alignment errors.
 * WARNING: This section is dependent on the length of an int32 (and thus a uint32)
 * being correct (4 bytes)!  Set CAREFUL_ALIGNMENT if it is not. */

# ifdef AVOID_BYTEORDER_INLINE

#define IVAL(buf,pos) (*(uint32 *)((char *)(buf) + (pos)))
#define SIVAL(buf,pos,val) IVAL(buf,pos)=((uint32)(val))

#define IVALu(buf,pos) IVAL(buf,pos)
#define SIVALu(buf,pos,val) SIVAL(buf,pos,val)

# else /* !AVOID_BYTEORDER_INLINE */

static inline uint32
IVALu(const uchar *buf, int pos)
{
	union {
		const uchar *b;
		const uint32 *num;
	} u;
	u.b = buf + pos;
	return *u.num;
}

static inline void
SIVALu(uchar *buf, int pos, uint32 val)
{
	union {
		uchar *b;
		uint32 *num;
	} u;
	u.b = buf + pos;
	*u.num = val;
}

static inline uint32
IVAL(const char *buf, int pos)
{
	return IVALu((uchar*)buf, pos);
}

static inline void
SIVAL(char *buf, int pos, uint32 val)
{
	SIVALu((uchar*)buf, pos, val);
}

# endif /* !AVOID_BYTEORDER_INLINE */

#endif /* !CAREFUL_ALIGNMENT */
Commit	Line	Data
0f78b815 WD	1	/*
	2	* Simple byteorder handling.
	3	*
	4	* Copyright (C) 1992-1995 Andrew Tridgell
d3d07a5e	5	* Copyright (C) 2007-2008 Wayne Davison
0f78b815 WD	6	*
0f78b815 WD	7	* This program is free software; you can redistribute it and/or modify
8e41b68e WD	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 3 of the License, or
	10	* (at your option) any later version.
0f78b815 WD	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
e7c67065	17	* You should have received a copy of the GNU General Public License along
4fd842f9	18	* with this program; if not, visit the http://fsf.org website.
0f78b815	19	*/
c627d613 AT	20
c627d613 AT	21	#undef CAREFUL_ALIGNMENT
df6350a8	22	#undef AVOID_BYTEORDER_INLINE
c627d613	23
36e6594d WD	24	/* We know that the x86 can handle misalignment and has the same
36e6594d WD	25	* byte order (LSB-first) as the 32-bit numbers we transmit. */
c627d613 AT	26	#ifdef __i386__
	27	#define CAREFUL_ALIGNMENT 0
	28	#endif
	29
	30	#ifndef CAREFUL_ALIGNMENT
	31	#define CAREFUL_ALIGNMENT 1
	32	#endif
	33
	34	#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
36e6594d	35	#define UVAL(buf,pos) ((uint32)CVAL(buf,pos))
c627d613	36
c627d613	37	#if CAREFUL_ALIGNMENT
df6350a8	38
36e6594d WD	39	#define PVAL(buf,pos) (UVAL(buf,pos)\|UVAL(buf,(pos)+1)<<8)
36e6594d WD	40	#define IVAL(buf,pos) (PVAL(buf,pos)\|PVAL(buf,(pos)+2)<<16)
c627d613 AT	41	#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
	42	#define SIVALX(buf,pos,val) (SSVALX(buf,pos,val&0xFFFF),SSVALX(buf,pos+2,val>>16))
	43	#define SIVAL(buf,pos,val) SIVALX((buf),(pos),((uint32)(val)))
df6350a8 WD	44
	45	#define IVALu(buf,pos) IVAL(buf,pos)
	46	#define SIVALu(buf,pos,val) SIVAL(buf,pos,val)
	47
	48	#else /* !CAREFUL_ALIGNMENT */
	49
	50	/* This handles things for architectures like the 386 that can handle alignment errors.
	51	* WARNING: This section is dependent on the length of an int32 (and thus a uint32)
	52	* being correct (4 bytes)! Set CAREFUL_ALIGNMENT if it is not. */
	53
	54	# ifdef AVOID_BYTEORDER_INLINE
	55
c627d613 AT	56	#define IVAL(buf,pos) ((uint32 )((char *)(buf) + (pos)))
c627d613 AT	57	#define SIVAL(buf,pos,val) IVAL(buf,pos)=((uint32)(val))
df6350a8 WD	58
	59	#define IVALu(buf,pos) IVAL(buf,pos)
	60	#define SIVALu(buf,pos,val) SIVAL(buf,pos,val)
	61
	62	# else /* !AVOID_BYTEORDER_INLINE */
	63
	64	static inline uint32
	65	IVALu(const uchar *buf, int pos)
	66	{
	67	union {
	68	const uchar *b;
	69	const uint32 *num;
	70	} u;
	71	u.b = buf + pos;
	72	return *u.num;
	73	}
	74
	75	static inline void
	76	SIVALu(uchar *buf, int pos, uint32 val)
	77	{
	78	union {
	79	uchar *b;
	80	uint32 *num;
	81	} u;
	82	u.b = buf + pos;
	83	*u.num = val;
	84	}
	85
	86	static inline uint32
	87	IVAL(const char *buf, int pos)
	88	{
	89	return IVALu((uchar*)buf, pos);
	90	}
	91
	92	static inline void
	93	SIVAL(char *buf, int pos, uint32 val)
	94	{
	95	SIVALu((uchar*)buf, pos, val);
	96	}
	97
	98	# endif /* !AVOID_BYTEORDER_INLINE */
	99
	100	#endif /* !CAREFUL_ALIGNMENT */