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-rw-r--r--src/strings/ffs.c55
1 files changed, 55 insertions, 0 deletions
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 <http://www.gnu.org/licenses/>.
+ */
+#include <strings.h>
+
+
+/**
+ * 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);
+}
+