| /* |
| * Copyright (C) 2009, Steven Rostedt <srostedt@redhat.com> |
| * |
| * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License (not later!) |
| * |
| * This program 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 General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| */ |
| #ifndef _TRACE_HASH_LOCAL_H |
| #define _TRACE_HASH_LOCAL_H |
| |
| static inline unsigned int trace_hash(int val) |
| { |
| int hash, tmp; |
| |
| hash = 12546869; /* random prime */ |
| |
| /* |
| * The following hash is based off of Paul Hsieh's super fast hash: |
| * http://www.azillionmonkeys.com/qed/hash.html |
| * Note, he released this code unde the GPL 2.0 license, which |
| * is the same as the license for the programs that use it here. |
| */ |
| |
| hash += (val & 0xffff); |
| tmp = (val >> 16) ^ hash; |
| hash = (hash << 16) ^ tmp; |
| hash += hash >> 11; |
| |
| hash ^= hash << 3; |
| hash += hash >> 5; |
| hash ^= hash << 4; |
| hash += hash >> 17; |
| hash ^= hash << 25; |
| hash += hash >> 6; |
| |
| return hash; |
| } |
| |
| #endif /* _TRACE_HASH_LOCAL_H */ |