1 files changed, 36 insertions, 0 deletions
diff --git a/crypto/test/src/util/utiltest/LongsTest.cs b/crypto/test/src/util/utiltest/LongsTest.cs
new file mode 100644
index 000000000..b2ddb6656
--- /dev/null
+++ b/crypto/test/src/util/utiltest/LongsTest.cs
@@ -0,0 +1,36 @@
+using System;
+
+using NUnit.Framework;
+
+namespace Org.BouncyCastle.Utilities.UtilTests
+{
+    [TestFixture]
+    public class LongsTest
+    {
+        [Test]
+        public void TestNumberOfLeadingZeros()
+        {
+            for (int i = 0; i < 63; ++i)
+            {
+                Assert.AreEqual(i, Longs.NumberOfLeadingZeros((long)(0x8000000000000000UL >> i)));
+                Assert.AreEqual(i, Longs.NumberOfLeadingZeros((long)(0xFFFFFFFFFFFFFFFFUL >> i)));
+            }
+
+            Assert.AreEqual(63, Longs.NumberOfLeadingZeros(1L));
+            Assert.AreEqual(64, Longs.NumberOfLeadingZeros(0L));
+        }
+
+        [Test]
+        public void TestNumberOfTrailingZeros()
+        {
+            for (int i = 0; i < 63; ++i)
+            {
+                Assert.AreEqual(i, Longs.NumberOfTrailingZeros(1L << i));
+                Assert.AreEqual(i, Longs.NumberOfTrailingZeros(-1L << i));
+            }
+
+            Assert.AreEqual(63, Longs.NumberOfTrailingZeros(long.MinValue));
+            Assert.AreEqual(64, Longs.NumberOfTrailingZeros(0L));
+        }
+    }
+}