1 /**
2 * compat.c - Tweaks for Windows compatibility
3 *
4 * Copyright (c) 2002 Richard Russon
5 * Copyright (c) 2002-2004 Anton Altaparmakov
6 *
7 * This program/include file is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as published
9 * by the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program/include file is distributed in the hope that it will be
13 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program (in the main directory of the Linux-NTFS
19 * distribution in the file COPYING); if not, write to the Free Software
20 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #ifdef WINDOWS
24
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28
29 #include "compat.h"
30
31 /* TODO: Add check for FFS in the configure script... (AIA) */
32
33 #ifndef HAVE_FFS
34 /**
35 * ffs - Find the first set bit in an int
36 * @x:
37 *
38 * Description...
39 *
40 * Returns:
41 */
ffs(int x)42 int ffs(int x)
43 {
44 int r = 1;
45
46 if (!x)
47 return 0;
48 if (!(x & 0xffff)) {
49 x >>= 16;
50 r += 16;
51 }
52 if (!(x & 0xff)) {
53 x >>= 8;
54 r += 8;
55 }
56 if (!(x & 0xf)) {
57 x >>= 4;
58 r += 4;
59 }
60 if (!(x & 3)) {
61 x >>= 2;
62 r += 2;
63 }
64 if (!(x & 1)) {
65 x >>= 1;
66 r += 1;
67 }
68 return r;
69 }
70 #endif /* HAVE_FFS */
71
72 #endif /* WINDOWS */
73
74