TESTING NEEDED: JIT Sparse Function Table, by riperiperi

src/ARMeilleure/Common/AddressTableLevel.cs

@@ -0,0 +1,44 @@
+namespace ARMeilleure.Common
+{
+    /// <summary>
+    /// Represents a level in an <see cref="IAddressTable{TEntry}"/>.
+    /// </summary>
+    public readonly struct AddressTableLevel
+    {
+        /// <summary>
+        /// Gets the index of the <see cref="Level"/> in the guest address.
+        /// </summary>
+        public int Index { get; }
+
+        /// <summary>
+        /// Gets the length of the <see cref="AddressTableLevel"/> in the guest address.
+        /// </summary>
+        public int Length { get; }
+
+        /// <summary>
+        /// Gets the mask which masks the bits used by the <see cref="AddressTableLevel"/>.
+        /// </summary>
+        public ulong Mask => ((1ul << Length) - 1) << Index;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AddressTableLevel"/> structure with the specified
+        /// <paramref name="index"/> and <paramref name="length"/>.
+        /// </summary>
+        /// <param name="index">Index of the <see cref="AddressTableLevel"/></param>
+        /// <param name="length">Length of the <see cref="AddressTableLevel"/></param>
+        public AddressTableLevel(int index, int length)
+        {
+            (Index, Length) = (index, length);
+        }
+
+        /// <summary>
+        /// Gets the value of the <see cref="AddressTableLevel"/> from the specified guest <paramref name="address"/>.
+        /// </summary>
+        /// <param name="address">Guest address</param>
+        /// <returns>Value of the <see cref="AddressTableLevel"/> from the specified guest <paramref name="address"/></returns>
+        public int GetValue(ulong address)
+        {
+            return (int)((address & Mask) >> Index);
+        }
+    }
+}

src/ARMeilleure/Common/AddressTablePresets.cs

@@ -0,0 +1,51 @@
+namespace ARMeilleure.Common
+{
+    public static class AddressTablePresets
+    {
+        private static readonly AddressTableLevel[] _levels64Bit =
+            new AddressTableLevel[]
+            {
+                new(31, 17),
+                new(23,  8),
+                new(15,  8),
+                new( 7,  8),
+                new( 2,  5),
+            };
+
+        private static readonly AddressTableLevel[] _levels32Bit =
+            new AddressTableLevel[]
+            {
+                new(31, 17),
+                new(23,  8),
+                new(15,  8),
+                new( 7,  8),
+                new( 1,  6),
+            };
+
+        private static readonly AddressTableLevel[] _levels64BitSparse =
+            new AddressTableLevel[]
+            {
+                new(23, 16),
+                new( 2, 21),
+            };
+
+        private static readonly AddressTableLevel[] _levels32BitSparse =
+            new AddressTableLevel[]
+            {
+                new(22, 10),
+                new( 1, 21),
+            };
+
+        public static AddressTableLevel[] GetArmPreset(bool for64Bits, bool sparse)
+        {
+            if (sparse)
+            {
+                return for64Bits ? _levels64BitSparse : _levels32BitSparse;
+            }
+            else
+            {
+                return for64Bits ? _levels64Bit : _levels32Bit;
+            }
+        }
+    }
+}

src/ARMeilleure/Common/Allocator.cs

@@ -2,7 +2,7 @@
 
 namespace ARMeilleure.Common
 {
-    unsafe abstract class Allocator : IDisposable
+    public unsafe abstract class Allocator : IDisposable
     {
         public T* Allocate<T>(ulong count = 1) where T : unmanaged
         {