| Petr Machata | 1721fc9 | 2013-01-21 16:14:20 +0100 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of ltrace. |
| 3 | * Copyright (C) 2013 Petr Machata, Red Hat Inc. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License as |
| 7 | * published by the Free Software Foundation; either version 2 of the |
| 8 | * License, or (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA |
| 18 | * 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #include "bits.h" |
| 22 | |
| 23 | /* This is called rarely, and any overhead will be lost in ptrace |
| 24 | * noise, so the algorithm doesn't need to be terribly clever. For |
| 25 | * the same reason we don't bother defining the corresponding _32 |
| 26 | * variant. */ |
| 27 | unsigned |
| 28 | bitcount(uint64_t u) |
| 29 | { |
| 30 | int c = 0; |
| 31 | for (; u > 0; u &= u - 1) |
| 32 | c++; |
| 33 | return c; |
| 34 | } |