/* $NetBSD: bswap64.c,v 1.1 2005/12/20 19:28:51 christos Exp $ */ | |
/* | |
* Written by Manuel Bouyer <bouyer@NetBSD.org>. | |
* Public domain. | |
*/ | |
//#include <sys/cdefs.h> | |
//#if defined(LIBC_SCCS) && !defined(lint) | |
//__RCSID("$NetBSD: bswap64.c,v 1.1 2005/12/20 19:28:51 christos Exp $"); | |
//#endif /* LIBC_SCCS and not lint */ | |
//#include <sys/types.h> | |
//#include <machine/bswap.h> | |
#undef bswap64 | |
UINT64 | |
bswap64(UINT64 x) | |
{ | |
#ifndef _LP64 | |
/* | |
* Assume we have wide enough registers to do it without touching | |
* memory. | |
*/ | |
return ( (x << 56) & 0xff00000000000000UL ) | | |
( (x << 40) & 0x00ff000000000000UL ) | | |
( (x << 24) & 0x0000ff0000000000UL ) | | |
( (x << 8) & 0x000000ff00000000UL ) | | |
( (x >> 8) & 0x00000000ff000000UL ) | | |
( (x >> 24) & 0x0000000000ff0000UL ) | | |
( (x >> 40) & 0x000000000000ff00UL ) | | |
( (x >> 56) & 0x00000000000000ffUL ); | |
#else | |
/* | |
* Split the operation in two 32bit steps. | |
*/ | |
u_int32_t tl, th; | |
th = bswap32((u_int32_t)(x & 0x00000000ffffffffULL)); | |
tl = bswap32((u_int32_t)((x >> 32) & 0x00000000ffffffffULL)); | |
return ((u_int64_t)th << 32) | tl; | |
#endif | |
} |