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freebsd/sys/i386/include/endian.h
Mike Barcroft d846855da8 o Don't require long long support in bswap64() functions.
o In i386's <machine/endian.h>, macros have some advantages over
  inlines, so change some inlines to macros.
o In i386's <machine/endian.h>, ungarbage collect word_swap_int()
  (previously __uint16_swap_uint32), it has some uses on i386's with
  PDP endianness.

Submitted by:	bde

o Move a comment up in <machine/endian.h> that was accidentially moved
  down a few revisions ago.
o Reenable userland's use of optimized inline-asm versions of
  byteorder(3) functions.
o Fix ordering of prototypes vs. redefinition of byteorder(3)
  functions, so that the non-GCC (libc asm) case has proper
  prototypes.
o Add proper prototypes for byteorder(3) functions in <sys/param.h>.
o Prevent redundant duplicate prototypes by making use of the
  _BYTEORDER_PROTOTYPED define.
o Move the bswap16(), bswap32(), bswap64() C functions into MD space
  for platforms in which asm versions don't exist.  This significantly
  reduces the complexity of some things at the cost of duplicate code.

Reviewed by:	bde
2002-03-09 21:02:16 +00:00

119 lines
3.8 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.
*
* @(#)endian.h 7.8 (Berkeley) 4/3/91
* $FreeBSD$
*/
#ifndef _MACHINE_ENDIAN_H_
#define _MACHINE_ENDIAN_H_
#include <sys/cdefs.h>
#include <machine/ansi.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
#endif /* ! _POSIX_SOURCE */
#ifdef __GNUC__
#define __word_swap_int(x) \
__extension__ ({ register __uint32_t __X = (x); \
__asm ("rorl $16, %0" : "+r" (__X)); \
__X; })
#if defined(_KERNEL) && (defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)) && !defined(I386_CPU)
#define __byte_swap_int(x) \
__extension__ ({ register __uint32_t __X = (x); \
__asm ("bswap %0" : "+r" (__X)); \
__X; })
#else
#define __byte_swap_int(x) \
__extension__ ({ register __uint32_t __X = (x); \
__asm ("xchgb %h0, %b0\n\trorl $16, %0\n\txchgb %h0, %b0" \
: "+q" (__X)); \
__X; })
#endif
#define __byte_swap_word(x) \
__extension__ ({ register __uint16_t __X = (x); \
__asm ("xchgb %h0, %b0" : "+q" (__X)); \
__X; })
static __inline __uint64_t
__bswap64(__uint64_t _x)
{
return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
((_x << 24) & ((__uint64_t)0xff << 40)) |
((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
}
static __inline __uint32_t
__bswap32(__uint32_t _x)
{
return (__byte_swap_int(_x));
}
static __inline __uint16_t
__bswap16(__uint16_t _x)
{
return (__byte_swap_word(_x));
}
#endif /* __GNUC__ */
#define __htonl(x) __bswap32(x)
#define __htons(x) __bswap16(x)
#define __ntohl(x) __bswap32(x)
#define __ntohs(x) __bswap16(x)
#endif /* !_MACHINE_ENDIAN_H_ */