Implement ffsl() and ffsll() using the compiler builtin __builtin_ctzl

now that all archs use at least gcc4.
ffsl() and ffsll() are now part of POSIX.
OK deraadt@, input from miod@ and jsg@

1 files changed, 26 insertions, 5 deletions

diff --git a/src/lib/libc/string/ffs.3 b/src/lib/libc/string/ffs.3
index e78ab99e8f..630db1c584 100644
--- a/src/lib/libc/string/ffs.3
+++ b/src/lib/libc/string/ffs.3
@@ -27,22 +27,31 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     $OpenBSD: ffs.3,v 1.11 2019/08/30 18:35:03 deraadt Exp $
+.\"     $OpenBSD: ffs.3,v 1.12 2025/10/24 11:30:06 claudio Exp $
 .\"
-.Dd $Mdocdate: August 30 2019 $
+.Dd $Mdocdate: October 24 2025 $
 .Dt FFS 3
 .Os
 .Sh NAME
-.Nm ffs
+.Nm ffs ,
+.Nm ffsl ,
+.Nm ffsll
 .Nd find first bit set in a bit string
 .Sh SYNOPSIS
 .In strings.h
 .Ft int
 .Fn ffs "int value"
+.Ft int
+.Fn ffsl "long value"
+.Ft int
+.Fn ffsll "long long value"
 .Sh DESCRIPTION
 The
-.Fn ffs
-function finds the first bit set in
+.Fn ffs ,
+.Fn ffsl
+and
+.Fn ffsll
+functions find the first bit set in
 .Fa value
 and returns the index of that bit.
 Bits are numbered starting from 1, starting at the rightmost bit.
@@ -54,8 +63,20 @@ The
 .Fn ffs
 function conforms to
 .St -p1003.1-2008 .
+The
+.Fn ffsl
+and
+.Fn ffsll
+functions conform to
+.St -p1003.1-2024 .
 .Sh HISTORY
 The
 .Fn ffs
 function first appeared in
 .Bx 4.2 .
+The
+.Fn ffsl
+and
+.Fn ffsll
+functions first appeared in
+.Ox 7.9 .