1 /*-
2 * See the file LICENSE for redistribution information.
3 *
4 * Copyright (c) 1996, 1997, 1998
5 * Sleepycat Software. All rights reserved.
6 */
7 /*
8 * Copyright (c) 1995, 1996
9 * The Regents of the University of California. All rights reserved.
10 *
11 * This code is derived from software contributed to Berkeley by
12 * Margo Seltzer.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. All advertising materials mentioning features or use of this software
23 * must display the following acknowledgement:
24 * This product includes software developed by the University of
25 * California, Berkeley and its contributors.
26 * 4. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * SUCH DAMAGE.
41 */
42
43 #include "config.h"
44
45 #ifndef lint
46 static const char sccsid[] = "@(#)db_log2.c 10.5 (Sleepycat) 4/26/98";
47 #endif /* not lint */
48
49 #ifndef NO_SYSTEM_INCLUDES
50 #include <sys/types.h>
51 #endif
52
53 #include "db_int.h"
54 #include "common_ext.h"
55
56 /*
57 * PUBLIC: u_int32_t __db_log2 __P((u_int32_t));
58 */
59 u_int32_t
__db_log2(num)60 __db_log2(num)
61 u_int32_t num;
62 {
63 u_int32_t i, limit;
64
65 limit = 1;
66 for (i = 0; limit < num; limit = limit << 1, i++)
67 ;
68 return (i);
69 }
70