freebsd-dev/sys/i386/include/endian.h
Bruce Evans 8bd28861d8 Fixed linting of and compilation of the gcc byte-swapping macros
properly.  Simply don't use the gcc macros if we're not gcc, and
declare prototypes for the byte-swapping functions in case the
macro versions are not used.  The previous fix was wrong and broke
libpcap, which abuses -Dlint.

Don't pollute the namespace if _POSIX_SOURCE is defined.  This is
broken - it makes almost everything in <machine/endian.h> inaccessible
if _POSIX_SOURCE is defined, yet <machine/endian.h> is not a POSIX
header.  Other systems don't do it any better.

Removed always-false `BYTE_ORDER == BIG_ENDIAN' ifdef.
Obtained from:	partly from Lite(2?) and NetBSD
1997-04-20 11:44:32 +00:00

123 lines
3.9 KiB
C

/*
* Copyright (c) 1987, 1991 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)endian.h 7.8 (Berkeley) 4/3/91
* $Id: endian.h,v 1.14 1997/03/17 00:51:51 nate Exp $
*/
#ifndef _MACHINE_ENDIAN_H_
#define _MACHINE_ENDIAN_H_
/*
* Define the order of 32-bit words in 64-bit words.
*/
#define _QUAD_HIGHWORD 1
#define _QUAD_LOWWORD 0
#ifndef _POSIX_SOURCE
/*
* Definitions for byte order, according to byte significance from low
* address to high.
*/
#define LITTLE_ENDIAN 1234 /* LSB first: i386, vax */
#define BIG_ENDIAN 4321 /* MSB first: 68000, ibm, net */
#define PDP_ENDIAN 3412 /* LSB first in word, MSW first in long */
#define BYTE_ORDER LITTLE_ENDIAN
#ifndef KERNEL
#include <sys/cdefs.h>
#else
#ifndef ACTUALLY_LKM_NOT_KERNEL
#include "opt_cpu.h"
#endif
#endif
__BEGIN_DECLS
unsigned long htonl __P((unsigned long));
unsigned short htons __P((unsigned short));
unsigned long ntohl __P((unsigned long));
unsigned short ntohs __P((unsigned short));
__END_DECLS
#define __word_swap_long(x) \
__extension__ ({ register u_long __X = (x); \
__asm ("rorl $16, %1" \
: "=r" (__X) \
: "0" (__X)); \
__X; })
#if defined(KERNEL) && (defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)) && !defined(I386_CPU)
#define __byte_swap_long(x) \
__extension__ ({ register u_long __X = (x); \
__asm ("bswap %0" \
: "=r" (__X) \
: "0" (__X)); \
__X; })
#else
#define __byte_swap_long(x) \
__extension__ ({ register u_long __X = (x); \
__asm ("xchgb %h1, %b1\n\trorl $16, %1\n\txchgb %h1, %b1" \
: "=q" (__X) \
: "0" (__X)); \
__X; })
#endif
#define __byte_swap_word(x) \
__extension__ ({ register u_short __X = (x); \
__asm ("xchgb %h1, %b1" \
: "=q" (__X) \
: "0" (__X)); \
__X; })
/*
* Macros for network/external number representation conversion.
*/
#ifdef __GNUC__
#define ntohl __byte_swap_long
#define ntohs __byte_swap_word
#define htonl __byte_swap_long
#define htons __byte_swap_word
#endif
#define NTOHL(x) ((x) = ntohl((u_long)(x)))
#define NTOHS(x) ((x) = ntohs((u_short)(x)))
#define HTONL(x) ((x) = htonl((u_long)(x)))
#define HTONS(x) ((x) = htons((u_short)(x)))
#endif /* ! _POSIX_SOURCE */
#endif /* !_MACHINE_ENDIAN_H_ */