From d0a041e7e8e5d26b530855dc75f35733b334ee54 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Wed, 2 Sep 2015 17:30:24 +0200 Subject: add ffs functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/strings/ffs.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 src/strings/ffs.c (limited to 'src') diff --git a/src/strings/ffs.c b/src/strings/ffs.c new file mode 100644 index 0000000..b0a6481 --- /dev/null +++ b/src/strings/ffs.c @@ -0,0 +1,55 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * 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, either version 3 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#include + + +/** + * Find the first set bit in an integer. + * + * @param i The integer + * @return The value of the least significant set bit, zero if none. + */ +int ffs(int i) +{ + return __builtin_ffs(i); +} + + +/** + * Find the first set bit in an integer. + * + * @param i The integer + * @return The value of the least significant set bit, zero if none. + */ +int ffsl(long i) +{ + return __builtin_ffsl(i); +} + + +/** + * Find the first set bit in an integer. + * + * @param i The integer + * @return The value of the least significant set bit, zero if none. + */ +int ffsll(long long i) +{ + return __builtin_ffsll(i); +} + -- cgit v1.2.3-70-g09d2