blob: b2decf94de768ff6087722441a3554b950fb4899 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
/* $NetBSD: bswap64.c,v 1.3 2009/03/16 05:59:21 cegger 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 1.3 2009/03/16 05:59:21 cegger Exp $");
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <machine/bswap.h>
#undef bswap64
uint64_t
bswap64(uint64_t x)
{
#ifdef _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.
*/
uint32_t tl, th;
th = bswap32((uint32_t)(x & 0x00000000ffffffffULL));
tl = bswap32((uint32_t)((x >> 32) & 0x00000000ffffffffULL));
return ((uint64_t)th << 32) | tl;
#endif
}
|
