- Renamed `NativeLibraryConfig.Default` to `NativeLibraryConfig.Instance`. It's not default any more as soon as you call `WithX`!

- using `Lazy<T>` to initialize it automatically.
 - Added in `AVX512` support for all dotnet versions (but not autodetected).
 - Added in AVX version auto detection.

LLama.Examples/Program.cs

@@ -7,7 +7,7 @@ Console.WriteLine(" __       __                                       ____     _
 
 Console.WriteLine("======================================================================================================");
 
-NativeLibraryConfig.Default.WithCuda().WithLogs();
+NativeLibraryConfig.Instance.WithCuda().WithLogs();
 
 NativeApi.llama_empty_call();
 Console.WriteLine();

LLama/Native/NativeApi.Load.cs

@@ -5,7 +5,6 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Runtime.InteropServices;
-using System.Text;
 using System.Text.Json;
 
 namespace LLama.Native
@@ -227,24 +226,15 @@ namespace LLama.Native
             }
             else if (platform != OSPlatform.OSX) // in macos there's absolutely no avx
             {
-#if NET8_0_OR_GREATER
-                if (configuration.AvxLevel == NativeLibraryConfig.AvxLevel.Avx512)
-                {
-                    result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.Avx512, prefix, suffix)));
-                    result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.Avx2, prefix, suffix)));
-                    result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.Avx, prefix, suffix)));
-                }
-                else 
-#endif
-                if (configuration.AvxLevel == NativeLibraryConfig.AvxLevel.Avx2)
-                {
+                if (configuration.AvxLevel >= NativeLibraryConfig.AvxLevel.Avx512)
+                    result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.Avx512, prefix, suffix));
+
+                if (configuration.AvxLevel >= NativeLibraryConfig.AvxLevel.Avx2)
                     result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.Avx2, prefix, suffix));
+                
+                if (configuration.AvxLevel >= NativeLibraryConfig.AvxLevel.Avx)
                     result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.Avx, prefix, suffix));
-                }
-                else if (configuration.AvxLevel == NativeLibraryConfig.AvxLevel.Avx)
-                {
-                    result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.Avx, prefix, suffix));
-                }
+
                 result.Add(GetAvxLibraryPath(NativeLibraryConfig.AvxLevel.None, prefix, suffix));
             }
 

LLama/Native/NativeLibraryConfig.cs

@@ -4,46 +4,34 @@ namespace LLama.Native
 {
 #if NET6_0_OR_GREATER
     /// <summary>
-    /// A class about configurations when loading native libraries. 
-    /// Note that it could be configured only once before any call to llama model apis.
+    /// Allows configuration of the native llama.cpp libraries to load and use.
+    /// All configuration must be done before using **any** other LLamaSharp methods!
     /// </summary>
-    public class NativeLibraryConfig
+    public sealed class NativeLibraryConfig
     {
-        private static NativeLibraryConfig? instance;
-        private static readonly object lockObject = new object();
-        public static NativeLibraryConfig Default
-        {
-            get
-            {
-                return GetInstance();
-            }
-        }
+        private static readonly Lazy<NativeLibraryConfig> _instance = new(() => new NativeLibraryConfig());
+
+        /// <summary>
+        /// Get the config instance
+        /// </summary>
+        public static NativeLibraryConfig Instance => _instance.Value;
 
         /// <summary>
         /// Whether there's already a config for native library.
         /// </summary>
         public static bool LibraryHasLoaded { get; internal set; } = false;
 
-        private string _libraryPath;
-        private bool _useCuda;
+        private string _libraryPath = string.Empty;
+        private bool _useCuda = true;
         private AvxLevel _avxLevel;
-        private bool _allowFallback;
-        private bool _skipCheck;
-        private bool _logging;
+        private bool _allowFallback = true;
+        private bool _skipCheck = false;
+        private bool _logging = false;
 
-        internal static NativeLibraryConfig GetInstance()
+        private static void ThrowIfLoaded()
         {
-            if (instance is null)
-            {
-                lock (lockObject)
-                {
-                    if (instance is null)
-                    {
-                        instance = new NativeLibraryConfig();
-                    }
-                }
-            }
-            return instance;
+            if (LibraryHasLoaded)
+                throw new InvalidOperationException("NativeLibraryConfig must be configured before using **any** other LLamaSharp methods!");
         }
 
         /// <summary>
@@ -51,13 +39,11 @@ namespace LLama.Native
         /// When this method is called, all the other configurations will be ignored.
         /// </summary>
         /// <param name="libraryPath"></param>
-        /// <exception cref="InvalidOperationException"></exception>
+        /// <exception cref="InvalidOperationException">Thrown if `LibraryHasLoaded` is true.</exception>
         public NativeLibraryConfig WithLibrary(string libraryPath)
         {
-            if (LibraryHasLoaded)
-            {
-                throw new InvalidOperationException("NativeLibraryConfig could be configured only once before any call to llama model apis.");
-            }
+            ThrowIfLoaded();
+
             _libraryPath = libraryPath;
             return this;
         }
@@ -67,13 +53,11 @@ namespace LLama.Native
         /// </summary>
         /// <param name="enable"></param>
         /// <returns></returns>
-        /// <exception cref="InvalidOperationException"></exception>
+        /// <exception cref="InvalidOperationException">Thrown if `LibraryHasLoaded` is true.</exception>
         public NativeLibraryConfig WithCuda(bool enable = true)
         {
-            if (LibraryHasLoaded)
-            {
-                throw new InvalidOperationException("NativeLibraryConfig could be configured only once before any call to llama model apis.");
-            }
+            ThrowIfLoaded();
+
             _useCuda = enable;
             return this;
         }
@@ -83,29 +67,25 @@ namespace LLama.Native
         /// </summary>
         /// <param name="level"></param>
         /// <returns></returns>
-        /// <exception cref="InvalidOperationException"></exception>
+        /// <exception cref="InvalidOperationException">Thrown if `LibraryHasLoaded` is true.</exception>
         public NativeLibraryConfig WithAvx(AvxLevel level)
         {
-            if (LibraryHasLoaded)
-            {
-                throw new InvalidOperationException("NativeLibraryConfig could be configured only once before any call to llama model apis.");
-            }
+            ThrowIfLoaded();
+
             _avxLevel = level;
             return this;
         }
 
         /// <summary>
-        /// Configure whether to allow fallback when there's not match for preffered settings.
+        /// Configure whether to allow fallback when there's no match for preferred settings.
         /// </summary>
         /// <param name="enable"></param>
         /// <returns></returns>
-        /// <exception cref="InvalidOperationException"></exception>
+        /// <exception cref="InvalidOperationException">Thrown if `LibraryHasLoaded` is true.</exception>
         public NativeLibraryConfig WithAutoFallback(bool enable = true)
         {
-            if (LibraryHasLoaded)
-            {
-                throw new InvalidOperationException("NativeLibraryConfig could be configured only once before any call to llama model apis.");
-            }
+            ThrowIfLoaded();
+
             _allowFallback = enable;
             return this;
         }
@@ -117,13 +97,11 @@ namespace LLama.Native
         /// </summary>
         /// <param name="enable"></param>
         /// <returns></returns>
-        /// <exception cref="InvalidOperationException"></exception>
+        /// <exception cref="InvalidOperationException">Thrown if `LibraryHasLoaded` is true.</exception>
         public NativeLibraryConfig SkipCheck(bool enable = true)
         {
-            if (LibraryHasLoaded)
-            {
-                throw new InvalidOperationException("NativeLibraryConfig could be configured only once before any call to llama model apis.");
-            }
+            ThrowIfLoaded();
+
             _skipCheck = enable;
             return this;
         }
@@ -133,24 +111,22 @@ namespace LLama.Native
         /// </summary>
         /// <param name="enable"></param>
         /// <returns></returns>
-        /// <exception cref="InvalidOperationException"></exception>
+        /// <exception cref="InvalidOperationException">Thrown if `LibraryHasLoaded` is true.</exception>
         public NativeLibraryConfig WithLogs(bool enable = true)
         {
-            if (LibraryHasLoaded)
-            {
-                throw new InvalidOperationException("NativeLibraryConfig could be configured only once before any call to llama model apis.");
-            }
+            ThrowIfLoaded();
+
             _logging = enable;
             return this;
         }
 
         internal static Description CheckAndGatherDescription()
         {
-            if (Default._allowFallback && Default._skipCheck)
+            if (Instance._allowFallback && Instance._skipCheck)
             {
                 throw new ArgumentException("Cannot skip the check when fallback is allowed.");
             }
-            return new Description(Default._libraryPath, Default._useCuda, Default._avxLevel, Default._allowFallback, Default._skipCheck, Default._logging);
+            return new Description(Instance._libraryPath, Instance._useCuda, Instance._avxLevel, Instance._allowFallback, Instance._skipCheck, Instance._logging);
         }
 
         internal static string AvxLevelToString(AvxLevel level)
@@ -163,19 +139,24 @@ namespace LLama.Native
 #if NET8_0_OR_GREATER
                 AvxLevel.Avx512 => "avx512"
 #endif
-                _ => throw new ArgumentException($"Cannot recognize Avx level {level}")
+                _ => throw new ArgumentException($"Unknown AvxLevel '{level}'")
             };
         }
 
-
+        /// <summary>
+        /// Private constructor prevents new instances of this class being created
+        /// </summary>
         private NativeLibraryConfig()
         {
-            _libraryPath = string.Empty;
-            _useCuda = true;
-            _avxLevel = AvxLevel.Avx2;
-            _allowFallback = true;
-            _skipCheck = false;
-            _logging = false;
+            // Automatically detect the highest supported AVX level
+            if (System.Runtime.Intrinsics.X86.Avx.IsSupported)
+                _avxLevel = AvxLevel.Avx;
+            if (System.Runtime.Intrinsics.X86.Avx2.IsSupported)
+                _avxLevel = AvxLevel.Avx2;
+#if NET8_0_OR_GREATER
+            if (System.Runtime.Intrinsics.X86.Avx512.IsSupported)
+                _avxLevel = AvxLevel.Avx512;
+#endif
         }
 
         /// <summary>
@@ -183,19 +164,28 @@ namespace LLama.Native
         /// </summary>
         public enum AvxLevel
         {
-            /// <inheritdoc />
-            None = 0,
-            /// <inheritdoc />
-            Avx = 1,
-            /// <inheritdoc />
-            Avx2 = 2,
-#if NET8_0_OR_GREATER
-            /// <inheritdoc />
-            Avx512 = 3,
-#endif
+            /// <summary>
+            /// No AVX
+            /// </summary>
+            None,
+
+            /// <summary>
+            /// Advanced Vector Extensions (supported by most processors after 2011)
+            /// </summary>
+            Avx,
+
+            /// <summary>
+            /// AVX2 (supported by most processors after 2013)
+            /// </summary>
+            Avx2,
+
+            /// <summary>
+            /// AVX512 (supported by some processors after 2016, not widely supported)
+            /// </summary>
+            Avx512,
         }
-        internal record Description(string Path = "", bool UseCuda = true, AvxLevel AvxLevel = AvxLevel.Avx2,
-            bool AllowFallback = true, bool SkipCheck = false, bool Logging = false);
+
+        internal record Description(string Path, bool UseCuda, AvxLevel AvxLevel, bool AllowFallback, bool SkipCheck, bool Logging);
     }
 #endif
-}
+        }