1 files changed, 33 insertions, 0 deletions
diff --git a/lib/ntdb/test/run-001-fls.c b/lib/ntdb/test/run-001-fls.c
new file mode 100644
index 0000000000..ec61294c6f
--- /dev/null
+++ b/lib/ntdb/test/run-001-fls.c
@@ -0,0 +1,33 @@
+#include "ntdb-source.h"
+#include "tap-interface.h"
+
+static unsigned int dumb_fls(uint64_t num)
+{
+	int i;
+
+	for (i = 63; i >= 0; i--) {
+		if (num & (1ULL << i))
+			break;
+	}
+	return i + 1;
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned int i, j;
+
+	plan_tests(64 * 64 + 2);
+
+	ok1(fls64(0) == 0);
+	ok1(dumb_fls(0) == 0);
+
+	for (i = 0; i < 64; i++) {
+		for (j = 0; j < 64; j++) {
+			uint64_t val = (1ULL << i) | (1ULL << j);
+			ok(fls64(val) == dumb_fls(val),
+			   "%llu -> %u should be %u", (long long)val,
+			   fls64(val), dumb_fls(val));
+		}
+	}
+	return exit_status();
+}