Import sources from 2011-03-30 iso image

1 files changed, 23 insertions, 0 deletions

diff --git a/sys/src/ape/lib/bsd/ffs.c b/sys/src/ape/lib/bsd/ffs.c
new file mode 100755
index 000000000..508345365
--- /dev/null
+++ b/sys/src/ape/lib/bsd/ffs.c
@@ -0,0 +1,23 @@
+/* Find the first set bit
+ * i.e. least signifigant 1 bit:
+ * 0 => 0
+ * 1 => 1
+ * 2 => 2
+ * 3 => 1
+ * 4 => 3
+ */
+
+int
+ffs(unsigned int mask)
+{
+	int i;
+
+	if (!mask)
+		return 0;
+	i = 1;
+	while (!(mask & 1)){
+		i++;
+		mask = mask >> 1;
+	}
+	return i;
+}