1 files changed, 57 insertions, 0 deletions
diff --git a/src/ARMeilleure/Common/BitUtils.cs b/src/ARMeilleure/Common/BitUtils.cs
new file mode 100644
index 00000000..e7697ff3
--- /dev/null
+++ b/src/ARMeilleure/Common/BitUtils.cs
@@ -0,0 +1,57 @@
+using System;
+using System.Numerics;
+
+namespace ARMeilleure.Common
+{
+    static class BitUtils
+    {
+        private static ReadOnlySpan<sbyte> HbsNibbleLut => new sbyte[] { -1, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3 };
+
+        public static long FillWithOnes(int bits)
+        {
+            return bits == 64 ? -1L : (1L << bits) - 1;
+        }
+
+        public static int HighestBitSet(int value)
+        {
+            return 31 - BitOperations.LeadingZeroCount((uint)value);
+        }
+
+        public static int HighestBitSetNibble(int value)
+        {
+            return HbsNibbleLut[value];
+        }
+
+        public static long Replicate(long bits, int size)
+        {
+            long output = 0;
+
+            for (int bit = 0; bit < 64; bit += size)
+            {
+                output |= bits << bit;
+            }
+
+            return output;
+        }
+
+        public static int RotateRight(int bits, int shift, int size)
+        {
+            return (int)RotateRight((uint)bits, shift, size);
+        }
+
+        public static uint RotateRight(uint bits, int shift, int size)
+        {
+            return (bits >> shift) | (bits << (size - shift));
+        }
+
+        public static long RotateRight(long bits, int shift, int size)
+        {
+            return (long)RotateRight((ulong)bits, shift, size);
+        }
+
+        public static ulong RotateRight(ulong bits, int shift, int size)
+        {
+            return (bits >> shift) | (bits << (size - shift));
+        }
+    }
+}