Add Highest/LowestOneBit methods

1 files changed, 28 insertions, 0 deletions

diff --git a/crypto/src/util/Longs.cs b/crypto/src/util/Longs.cs
index 4d675bdba..a2d7dde0f 100644
--- a/crypto/src/util/Longs.cs
+++ b/crypto/src/util/Longs.cs
@@ -15,6 +15,34 @@ namespace Org.BouncyCastle.Utilities
             0x3E, 0x33, 0x05, 0x19, 0x24, 0x27, 0x20, 0x2E, 0x3C, 0x2C, 0x2A, 0x14, 0x16, 0x39, 0x10, 0x09,
             0x32, 0x18, 0x23, 0x1F, 0x3B, 0x13, 0x38, 0x0F, 0x31, 0x1E, 0x12, 0x0E, 0x1D, 0x0D, 0x0C, 0x0B };
 
+        public static long HighestOneBit(long i)
+        {
+            return (long)HighestOneBit((ulong)i);
+        }
+
+        [CLSCompliantAttribute(false)]
+        public static ulong HighestOneBit(ulong i)
+        {
+            i |= i >>  1;
+            i |= i >>  2;
+            i |= i >>  4;
+            i |= i >>  8;
+            i |= i >> 16;
+            i |= i >> 32;
+            return i - (i >> 1);
+        }
+
+        public static long LowestOneBit(long i)
+        {
+            return i & -i;
+        }
+
+        [CLSCompliantAttribute(false)]
+        public static ulong LowestOneBit(ulong i)
+        {
+            return (ulong)LowestOneBit((long)i);
+        }
+
         public static int NumberOfLeadingZeros(long i)
         {
             int x = (int)(i >> 32), n = 0;