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simplesshd/rsync/byteorder.h
2014-12-21 17:56:03 -05:00

125 lines
3.1 KiB
C

/*
* Simple byteorder handling.
*
* Copyright (C) 1992-1995 Andrew Tridgell
* Copyright (C) 2007-2014 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. */
#if defined __i386__ || defined __i486__ || defined __i586__ || defined __i686__ || __amd64
#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 IVAL64(buf,pos) (IVAL(buf,pos)|(int64)IVAL(buf,(pos)+4)<<32)
#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 SIVAL64(buf,pos,val) (SIVAL(buf,pos,val),SIVAL(buf,(pos)+4,(val)>>32))
#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);
}
static inline int64
IVAL64(const char *buf, int pos)
{
union {
const char *b;
const int64 *num;
} u;
u.b = buf + pos;
return *u.num;
}
static inline void
SIVAL64(char *buf, int pos, int64 val)
{
union {
char *b;
int64 *num;
} u;
u.b = buf + pos;
*u.num = val;
}
# endif /* !AVOID_BYTEORDER_INLINE */
#endif /* !CAREFUL_ALIGNMENT */