1/* 2 * Written by Manuel Bouyer <bouyer@netbsd.org>. 3 * Public domain. 4 */ 5 6#include <sys/cdefs.h> 7__FBSDID("$FreeBSD$"); 8 9#if defined(LIBC_SCCS) && !defined(lint) 10static char *rcsid = "$NetBSD: bswap32.c,v 1.1 1997/10/09 15:42:33 bouyer Exp $"; 11static char *rcsid = "$NetBSD: bswap64.c,v 1.3 2009/03/16 05:59:21 cegger Exp $"; 12#endif 13 14#include <sys/types.h> 15 16#undef bswap32 17#undef bswap64 18 19u_int32_t bswap32(u_int32_t x); 20u_int64_t bswap64(u_int64_t x); 21 22u_int32_t 23bswap32(u_int32_t x) 24{ 25 return ((x << 24) & 0xff000000 ) | 26 ((x << 8) & 0x00ff0000 ) | 27 ((x >> 8) & 0x0000ff00 ) | 28 ((x >> 24) & 0x000000ff ); 29} 30 31u_int64_t 32bswap64(u_int64_t x) 33{ 34#ifdef __LP64__ 35 /* 36 * Assume we have wide enough registers to do it without touching 37 * memory. 38 */ 39 return ( (x << 56) & 0xff00000000000000UL ) | 40 ( (x << 40) & 0x00ff000000000000UL ) | 41 ( (x << 24) & 0x0000ff0000000000UL ) | 42 ( (x << 8) & 0x000000ff00000000UL ) | 43 ( (x >> 8) & 0x00000000ff000000UL ) | 44 ( (x >> 24) & 0x0000000000ff0000UL ) | 45 ( (x >> 40) & 0x000000000000ff00UL ) | 46 ( (x >> 56) & 0x00000000000000ffUL ); 47#else 48 /* 49 * Split the operation in two 32bit steps. 50 */ 51 u_int32_t tl, th; 52 53 th = bswap32((u_int32_t)(x & 0x00000000ffffffffULL)); 54 tl = bswap32((u_int32_t)((x >> 32) & 0x00000000ffffffffULL)); 55 return ((u_int64_t)th << 32) | tl; 56#endif 57} 58