Initial work

Ryujinx.Graphics.Shader/Decoders/BitfieldExtensions.cs

@@ -0,0 +1,25 @@
+namespace Ryujinx.Graphics.Shader.Decoders
+{
+    static class BitfieldExtensions
+    {
+        public static bool Extract(this int value, int lsb)
+        {
+            return ((int)(value >> lsb) & 1) != 0;
+        }
+
+        public static int Extract(this int value, int lsb, int length)
+        {
+            return (int)(value >> lsb) & (int)(uint.MaxValue >> (32 - length));
+        }
+
+        public static bool Extract(this long value, int lsb)
+        {
+            return ((int)(value >> lsb) & 1) != 0;
+        }
+
+        public static int Extract(this long value, int lsb, int length)
+        {
+            return (int)(value >> lsb) & (int)(uint.MaxValue >> (32 - length));
+        }
+    }
+}