| | 1 | /*- |
| | 2 | * Copyright (c) 1990, 1993, 1994 |
| | 3 | * The Regents of the University of California. All rights reserved. |
| | 4 | * |
| | 5 | * This code is derived from software contributed to Berkeley by |
| | 6 | * Margo Seltzer. |
| | 7 | * |
| | 8 | * Redistribution and use in source and binary forms, with or without |
| | 9 | * modification, are permitted provided that the following conditions |
| | 10 | * are met: |
| | 11 | * 1. Redistributions of source code must retain the above copyright |
| | 12 | * notice, this list of conditions and the following disclaimer. |
| | 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| | 14 | * notice, this list of conditions and the following disclaimer in the |
| | 15 | * documentation and/or other materials provided with the distribution. |
| | 16 | * 4. Neither the name of the University nor the names of its contributors |
| | 17 | * may be used to endorse or promote products derived from this software |
| | 18 | * without specific prior written permission. |
| | 19 | * |
| | 20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| | 21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| | 22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| | 23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| | 24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| | 25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| | 26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| | 27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| | 28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| | 29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| | 30 | * SUCH DAMAGE. |
| | 31 | */ |
| | 32 | |
| | 33 | #if defined(LIBC_SCCS) && !defined(lint) |
| | 34 | static char sccsid[] = "@(#)hash_log2.c 8.2 (Berkeley) 5/31/94"; |
| | 35 | #endif /* LIBC_SCCS and not lint */ |
| | 36 | #include <sys/cdefs.h> |
| | 37 | __FBSDID("$FreeBSD: src/lib/libc/db/hash/hash_log2.c,v 1.5 2009/03/28 05:45:29 delphij Exp $"); |
| | 38 | |
| | 39 | #include <db.h> |
| | 40 | #include "hash.h" |
| | 41 | #include "page.h" |
| | 42 | #include "hash_extern.h" |
| | 43 | |
| | 44 | u_int32_t |
| | 45 | __log2(u_int32_t num) |
| | 46 | { |
| | 47 | u_int32_t i, limit; |
| | 48 | |
| | 49 | limit = 1; |
| | 50 | for (i = 0; limit < num; limit = limit << 1, i++); |
| | 51 | return (i); |
| | 52 | } |
projects / apple / libc.git / blame_incremental