/***************************************************************************** * ffsllp.c: GNU ffsll() replacement ***************************************************************************** * Copyright © 2015 Rémi Denis-Courmont * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser 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. *****************************************************************************/ #ifdef HAVE_CONFIG_H # include #endif #include int ffsll(unsigned long long x) { for (unsigned i = 0; i < sizeof (x) * CHAR_BIT; i++) if ((x >> i) & 1) return i + 1; return 0; }