Return to byteorder.h CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / rsync

v 3.1.0

    1: /*
    2:  * Simple byteorder handling.
    3:  *
    4:  * Copyright (C) 1992-1995 Andrew Tridgell
    5:  * Copyright (C) 2007-2013 Wayne Davison
    6:  *
    7:  * This program is free software; you can redistribute it and/or modify
    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.
   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:  *
   17:  * You should have received a copy of the GNU General Public License along
   18:  * with this program; if not, visit the http://fsf.org website.
   19:  */
   20: 
   21: #undef CAREFUL_ALIGNMENT
   22: #undef AVOID_BYTEORDER_INLINE
   23: 
   24: /* We know that the x86 can handle misalignment and has the same
   25:  * byte order (LSB-first) as the 32-bit numbers we transmit. */
   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])
   35: #define UVAL(buf,pos) ((uint32)CVAL(buf,pos))
   36: 
   37: #if CAREFUL_ALIGNMENT
   38: 
   39: #define PVAL(buf,pos) (UVAL(buf,pos)|UVAL(buf,(pos)+1)<<8)
   40: #define IVAL(buf,pos) (PVAL(buf,pos)|PVAL(buf,(pos)+2)<<16)
   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)))
   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: 
   56: #define IVAL(buf,pos) (*(uint32 *)((char *)(buf) + (pos)))
   57: #define SIVAL(buf,pos,val) IVAL(buf,pos)=((uint32)(val))
   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 */