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
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
/* l4/math.h - Public interface to Hurd mathematical support functions.
Copyright (C) 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
Written by Marcus Brinkmann <marcus@gnu.org>.
This file is part of the GNU Hurd.
The GNU Hurd is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License
as published by the Free Software Foundation; either version 2.1 of
the License, or (at your option) any later version.
The GNU Hurd is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU L4 library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#ifndef _HURD_MATH_H
#define _HURD_MATH_H
#include <stdint.h>
#include <bits/wordsize.h>
/* Return 0 if DATA is 0, or the bit number of the most significant
bit set in DATA. The least significant bit is 1, the most
significant bit 32 resp. 64. */
static inline uintptr_t
vg_msb (uintptr_t data)
{
if (! data)
return 0;
#if __WORDSIZE == 64
return 8 * sizeof (data) - __builtin_clzll (data);
#else
return 8 * sizeof (data) - __builtin_clz (data);
#endif
}
static inline uintptr_t
vg_msb64 (uint64_t data)
{
if (! data)
return 0;
return 8 * sizeof (data) - __builtin_clzll (data);
}
/* Return 0 if DATA is 0, or the bit number of the least significant
bit set in DATA. The least significant bit is 1, the most
significant bit 32 resp. 64. */
static inline uintptr_t
vg_lsb (uintptr_t data)
{
#if __WORDSIZE == 64
return __builtin_ffsll (data);
#else
return __builtin_ffs (data);
#endif
}
static inline uintptr_t
vg_lsb64 (uint64_t data)
{
return __builtin_ffsll (data);
}
#endif
|
