perf: fix performance of intrisics

This changes removes the CPU-arch support provider interfaces that were introduced with 87b6dbdd56. That commit worsened the performance of the intrinsic methods because it resulted in a box when upcasting the System_SupportProvider value type to an interface, removing the potential for JIT to optimise the code path.

X10D.Tests/src/Collections/ByteTests.cs

@@ -1,5 +1,5 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System.Runtime.Intrinsics.X86;
-using Moq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
 using X10D.Collections;
 
 namespace X10D.Tests.Collections;
@@ -10,7 +10,8 @@ public class ByteTests
     [TestMethod]
     public void Unpack_ShouldUnpackToArrayCorrectly()
     {
-        bool[] bits = ((byte)0b11010100).Unpack();
+        const byte value = 0b11010100;
+        bool[] bits = value.Unpack();
 
         Assert.AreEqual(8, bits.Length);
 
@@ -27,8 +28,9 @@ public class ByteTests
     [TestMethod]
     public void Unpack_ShouldUnpackToSpanCorrectly()
     {
+        const byte value = 0b11010100;
         Span<bool> bits = stackalloc bool[8];
-        ((byte)0b11010100).Unpack(bits);
+        value.Unpack(bits);
 
         Assert.IsFalse(bits[0]);
         Assert.IsFalse(bits[1]);
@@ -41,14 +43,35 @@ public class ByteTests
     }
 
 #if NET5_0_OR_GREATER
-    [TestMethod]
-    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallbackImplementation()
-    {
-        var mock = new Mock<ISsse3SupportProvider>();
-        mock.Setup(provider => provider.IsSupported).Returns(false);
 
+    [TestMethod]
+    public void UnpackInternal_Fallback_ShouldUnpackToSpanCorrectly()
+    {
+        const byte value = 0b11010100;
         Span<bool> bits = stackalloc bool[8];
-        ((byte)0b11010100).UnpackInternal(bits, mock.Object);
+        value.UnpackInternal_Fallback(bits);
+
+        Assert.IsFalse(bits[0]);
+        Assert.IsFalse(bits[1]);
+        Assert.IsTrue(bits[2]);
+        Assert.IsFalse(bits[3]);
+        Assert.IsTrue(bits[4]);
+        Assert.IsFalse(bits[5]);
+        Assert.IsTrue(bits[6]);
+        Assert.IsTrue(bits[7]);
+    }
+
+    [TestMethod]
+    public void UnpackInternal_Ssse3_ShouldUnpackToSpanCorrectly()
+    {
+        if (!Sse3.IsSupported)
+        {
+            return;
+        }
+
+        const byte value = 0b11010100;
+        Span<bool> bits = stackalloc bool[8];
+        value.UnpackInternal_Ssse3(bits);
 
         Assert.IsFalse(bits[0]);
         Assert.IsFalse(bits[1]);
@@ -64,7 +87,8 @@ public class ByteTests
     [TestMethod]
     public void Unpack_ShouldRepackEqually()
     {
-        Assert.AreEqual(0b11010100, ((byte)0b11010100).Unpack().PackByte());
+        const byte value = 0b11010100;
+        Assert.AreEqual(value, value.Unpack().PackByte());
     }
 
     [TestMethod]
@@ -72,8 +96,9 @@ public class ByteTests
     {
         Assert.ThrowsException<ArgumentException>(() =>
         {
+            const byte value = 0b11010100;
             Span<bool> bits = stackalloc bool[0];
-            ((byte)0b11010100).Unpack(bits);
+            value.Unpack(bits);
         });
     }
 }

X10D.Tests/src/Collections/Int16Tests.cs

@@ -1,5 +1,5 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System.Runtime.Intrinsics.X86;
-using Moq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
 using X10D.Collections;
 
 namespace X10D.Tests.Collections;
@@ -10,7 +10,8 @@ public class Int16Tests
     [TestMethod]
     public void Unpack_ShouldUnpackToArrayCorrectly()
     {
-        bool[] bits = ((short)0b11010100).Unpack();
+        const short value = 0b11010100;
+        bool[] bits = value.Unpack();
 
         Assert.AreEqual(16, bits.Length);
 
@@ -32,8 +33,31 @@ public class Int16Tests
     [TestMethod]
     public void Unpack_ShouldUnpackToSpanCorrectly()
     {
+        const short value = 0b11010100;
         Span<bool> bits = stackalloc bool[16];
-        ((short)0b11010100).Unpack(bits);
+        value.Unpack(bits);
+
+        Assert.IsFalse(bits[0]);
+        Assert.IsFalse(bits[1]);
+        Assert.IsTrue(bits[2]);
+        Assert.IsFalse(bits[3]);
+        Assert.IsTrue(bits[4]);
+        Assert.IsFalse(bits[5]);
+        Assert.IsTrue(bits[6]);
+        Assert.IsTrue(bits[7]);
+
+        for (var index = 8; index < 16; index++)
+        {
+            Assert.IsFalse(bits[index]);
+        }
+    }
+
+    [TestMethod]
+    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallbackImplementation()
+    {
+        const short value = 0b11010100;
+        Span<bool> bits = stackalloc bool[16];
+        value.UnpackInternal_Fallback(bits);
 
         Assert.IsFalse(bits[0]);
         Assert.IsFalse(bits[1]);
@@ -52,13 +76,16 @@ public class Int16Tests
 
 #if NET5_0_OR_GREATER
     [TestMethod]
-    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallbackImplementation()
+    public void UnpackInternal_Ssse3_ShouldUnpackToSpanCorrectly()
     {
-        var mock = new Mock<ISsse3SupportProvider>();
+        if (!Sse3.IsSupported)
-        mock.Setup(provider => provider.IsSupported).Returns(false);
+        {
+            return;
+        }
 
+        const short value = 0b11010100;
         Span<bool> bits = stackalloc bool[16];
-        ((short)0b11010100).UnpackInternal(bits, mock.Object);
+        value.UnpackInternal_Ssse3(bits);
 
         Assert.IsFalse(bits[0]);
         Assert.IsFalse(bits[1]);
@@ -79,7 +106,8 @@ public class Int16Tests
     [TestMethod]
     public void Unpack_ShouldRepackEqually()
     {
-        Assert.AreEqual(0b11010100, ((short)0b11010100).Unpack().PackInt16());
+        const short value = 0b11010100;
+        Assert.AreEqual(value, value.Unpack().PackInt16());
     }
 
     [TestMethod]
@@ -87,8 +115,9 @@ public class Int16Tests
     {
         Assert.ThrowsException<ArgumentException>(() =>
         {
+            const short value = 0b11010100;
             Span<bool> bits = stackalloc bool[0];
-            ((short)0b11010100).Unpack(bits);
+            value.Unpack(bits);
         });
     }
 }

X10D.Tests/src/Collections/Int32Tests.cs

@@ -1,5 +1,5 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System.Runtime.Intrinsics.X86;
-using Moq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
 using X10D.Collections;
 
 namespace X10D.Tests.Collections;
@@ -10,7 +10,8 @@ public class Int32Tests
     [TestMethod]
     public void Unpack_ShouldUnpackToArrayCorrectly()
     {
-        bool[] bits = 0b11010100.Unpack();
+        const int value = 0b11010100;
+        bool[] bits = value.Unpack();
 
         Assert.AreEqual(32, bits.Length);
 
@@ -32,8 +33,31 @@ public class Int32Tests
     [TestMethod]
     public void Unpack_ShouldUnpackToSpanCorrectly()
     {
+        const int value = 0b11010100;
         Span<bool> bits = stackalloc bool[32];
-        0b11010100.Unpack(bits);
+        value.Unpack(bits);
+
+        Assert.IsFalse(bits[0]);
+        Assert.IsFalse(bits[1]);
+        Assert.IsTrue(bits[2]);
+        Assert.IsFalse(bits[3]);
+        Assert.IsTrue(bits[4]);
+        Assert.IsFalse(bits[5]);
+        Assert.IsTrue(bits[6]);
+        Assert.IsTrue(bits[7]);
+
+        for (var index = 8; index < 32; index++)
+        {
+            Assert.IsFalse(bits[index]);
+        }
+    }
+
+    [TestMethod]
+    public void UnpackInternal_Fallback_ShouldUnpackToSpanCorrectly()
+    {
+        const int value = 0b11010100;
+        Span<bool> bits = stackalloc bool[32];
+        value.UnpackInternal_Fallback(bits);
 
         Assert.IsFalse(bits[0]);
         Assert.IsFalse(bits[1]);
@@ -52,15 +76,16 @@ public class Int32Tests
 
 #if NET5_0_OR_GREATER
     [TestMethod]
-    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallbackFromAvx2()
+    public void UnpackInternal_Ssse3_ShouldUnpackToSpanCorrectly()
     {
-        var ssse3Mock = new Mock<ISsse3SupportProvider>();
+        if (!Ssse3.IsSupported)
-        var avx2Mock = new Mock<IAvx2SupportProvider>();
+        {
-        avx2Mock.Setup(provider => provider.IsSupported).Returns(false);
+            return;
-        ssse3Mock.Setup(provider => provider.IsSupported).Returns(true);
+        }
 
+        const int value = 0b11010100;
         Span<bool> bits = stackalloc bool[32];
-        0b11010100.UnpackInternal(bits, ssse3Mock.Object, avx2Mock.Object);
+        value.UnpackInternal_Ssse3(bits);
 
         Assert.IsFalse(bits[0]);
         Assert.IsFalse(bits[1]);
@@ -78,15 +103,16 @@ public class Int32Tests
     }
 
     [TestMethod]
-    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallback()
+    public void UnpackInternal_Avx2_ShouldUnpackToSpanCorrectly()
     {
-        var ssse3Mock = new Mock<ISsse3SupportProvider>();
+        if (!Avx2.IsSupported)
-        var avx2Mock = new Mock<IAvx2SupportProvider>();
+        {
-        ssse3Mock.Setup(provider => provider.IsSupported).Returns(false);
+            return;
-        avx2Mock.Setup(provider => provider.IsSupported).Returns(false);
+        }
 
+        const int value = 0b11010100;
         Span<bool> bits = stackalloc bool[32];
-        0b11010100.UnpackInternal(bits, ssse3Mock.Object, avx2Mock.Object);
+        value.UnpackInternal_Avx2(bits);
 
         Assert.IsFalse(bits[0]);
         Assert.IsFalse(bits[1]);
@@ -102,13 +128,13 @@ public class Int32Tests
             Assert.IsFalse(bits[index]);
         }
     }
-
 #endif
 
     [TestMethod]
     public void Unpack_ShouldRepackEqually()
     {
-        Assert.AreEqual(0b11010100, 0b11010100.Unpack().PackInt32());
+        const int value = 0b11010100;
+        Assert.AreEqual(value, value.Unpack().PackInt32());
     }
 
     [TestMethod]
@@ -116,8 +142,9 @@ public class Int32Tests
     {
         Assert.ThrowsException<ArgumentException>(() =>
         {
+            const int value = 0b11010100;
             Span<bool> bits = stackalloc bool[0];
-            0b11010100.Unpack(bits);
+            value.Unpack(bits);
         });
     }
 }

X10D.Tests/src/Core/IntrinsicTests.cs

@@ -1,7 +1,7 @@
 #if NET6_0_OR_GREATER
 using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.X86;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using Moq;
 using X10D.Core;
 
 namespace X10D.Tests.Core;
@@ -12,9 +12,6 @@ public class IntrinsicTests
     [TestMethod]
     public void CorrectBoolean_ShouldReturnExpectedVector64Result_GivenInputVector()
     {
-        var mock = new Mock<ISse2SupportProvider>();
-        mock.Setup(provider => provider.IsSupported).Returns(true);
-
         var inputVector = Vector64.Create(0, 1, 2, 0, 3, 0, 0, (byte)4);
         var expectedResult = Vector64.Create(0, 1, 1, 0, 1, 0, 0, (byte)1);
 
@@ -24,89 +21,86 @@ public class IntrinsicTests
     }
 
     [TestMethod]
-    public void CorrectBoolean_ShouldReturnExpectedVector128Result_GivenInputVector()
+    public void CorrectBooleanInternal_Fallback_ShouldReturnExpectedVector128Result_GivenInputVector()
     {
-        var mock = new Mock<ISse2SupportProvider>();
-        mock.Setup(provider => provider.IsSupported).Returns(true);
-
         var inputVector = Vector128.Create(0, 1, 2, 0, 3, 0, 0, 4, 5, 0, 0, 6, 0, 0, 7, (byte)8);
         var expectedResult = Vector128.Create(0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, (byte)1);
 
-        Vector128<byte> result = inputVector.CorrectBooleanInternal(mock.Object);
+        Vector128<byte> result = inputVector.CorrectBooleanInternal_Fallback();
 
         Assert.AreEqual(expectedResult, result);
     }
 
     [TestMethod]
-    public void CorrectBoolean_ShouldReturnExpectedVector128Result_WhenSse2NotSupported()
+    public void CorrectBooleanInternal_Sse2_ShouldReturnExpectedVector128Result_GivenInputVector()
     {
-        var mock = new Mock<ISse2SupportProvider>();
+        if (!Sse2.IsSupported)
-        mock.Setup(provider => provider.IsSupported).Returns(false);
+        {
+            return;
+        }
 
         var inputVector = Vector128.Create(0, 1, 2, 0, 3, 0, 0, 4, 5, 0, 0, 6, 0, 0, 7, (byte)8);
         var expectedResult = Vector128.Create(0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, (byte)1);
 
-        Vector128<byte> result = inputVector.CorrectBooleanInternal(mock.Object);
+        Vector128<byte> result = inputVector.CorrectBooleanInternal_Sse2();
 
         Assert.AreEqual(expectedResult, result);
     }
 
     [TestMethod]
-    public void CorrectBoolean_ShouldReturnExpectedVector256Result_GivenInputVector()
+    public void CorrectBooleanInternal_Avx2_ShouldReturnExpectedVector256Result_GivenInputVector()
     {
-        var mock = new Mock<IAvx2SupportProvider>();
+        if (!Avx2.IsSupported)
-        mock.Setup(provider => provider.IsSupported).Returns(true);
+        {
+            return;
+        }
 
         var inputVector = Vector256.Create(0, 1, 2, 0, 3, 0, 0, 4, 5, 0, 0, 6, 0, 0, 7, 8, 0, 1, 2, 0, 3, 0, 0, 4, 5, 0, 0, 6, 0,
             0, 7, (byte)8);
         var expectedResult = Vector256.Create(0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1,
             0, 0, 1, (byte)1);
 
-        Vector256<byte> result = inputVector.CorrectBooleanInternal(mock.Object);
+        Vector256<byte> result = inputVector.CorrectBooleanInternal_Avx2();
 
         Assert.AreEqual(expectedResult, result);
     }
 
     [TestMethod]
-    public void CorrectBoolean_ShouldReturnExpectedVector256Result_WhenSse2NotSupported()
+    public void CorrectBooleanInternal_Fallback_ShouldReturnExpectedVector256Result_GivenInputVector()
     {
-        var mock = new Mock<IAvx2SupportProvider>();
-        mock.Setup(provider => provider.IsSupported).Returns(false);
-
         var inputVector = Vector256.Create(0, 1, 2, 0, 3, 0, 0, 4, 5, 0, 0, 6, 0, 0, 7, 8, 0, 1, 2, 0, 3, 0, 0, 4, 5, 0, 0, 6, 0,
             0, 7, (byte)8);
         var expectedResult = Vector256.Create(0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1,
             0, 0, 1, (byte)1);
 
-        Vector256<byte> result = inputVector.CorrectBooleanInternal(mock.Object);
+        Vector256<byte> result = inputVector.CorrectBooleanInternal_Fallback();
 
         Assert.AreEqual(expectedResult, result);
     }
 
     [TestMethod]
-    public void ReverseElements_ShouldReturnExpectedVector128Result_GivenInputVector()
+    public void ReverseElementsInternal_Fallback_ShouldReturnExpectedVector128Result_GivenInputVector()
     {
-        var mock = new Mock<ISse2SupportProvider>();
-        mock.Setup(provider => provider.IsSupported).Returns(true);
-
         var inputVector = Vector128.Create(42UL, 69UL);
         var expectedResult = Vector128.Create(69UL, 42UL);
 
-        Vector128<ulong> result = inputVector.ReverseElementsInternal(mock.Object);
+        Vector128<ulong> result = inputVector.ReverseElementsInternal_Fallback();
 
         Assert.AreEqual(expectedResult, result);
     }
 
     [TestMethod]
-    public void ReverseElements_ShouldReturnExpectedVector128Result_WhenSse2NotSupported()
+    public void ReverseElementsInternal_Sse2_ShouldReturnExpectedVector128Result_GivenInputVector()
     {
-        var mock = new Mock<ISse2SupportProvider>();
+        if (!Sse2.IsSupported)
-        mock.Setup(provider => provider.IsSupported).Returns(false);
+        {
+            return;
+        }
 
         var inputVector = Vector128.Create(42UL, 69UL);
         var expectedResult = Vector128.Create(69UL, 42UL);
 
-        Vector128<ulong> result = inputVector.ReverseElementsInternal(mock.Object);
+        Vector128<ulong> result = inputVector.ReverseElementsInternal_Sse2();
 
         Assert.AreEqual(expectedResult, result);
     }

X10D/src/Collections/ByteExtensions.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
 
 #if NETCOREAPP3_0_OR_GREATER
 using System.Runtime.Intrinsics;
@@ -21,6 +22,11 @@ public static class ByteExtensions
     /// <param name="value">The value to unpack.</param>
     /// <returns>An array of <see cref="bool" /> with length 8.</returns>
     [Pure]
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
     public static bool[] Unpack(this byte value)
     {
         var buffer = new bool[Size];
@@ -35,20 +41,12 @@ public static class ByteExtensions
     /// <param name="destination">When this method returns, contains the unpacked booleans from <paramref name="value" />.</param>
     /// <exception cref="ArgumentException"><paramref name="destination" /> is not large enough to contain the result.</exception>
     [ExcludeFromCodeCoverage]
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
     public static void Unpack(this byte value, Span<bool> destination)
-    {
-#if NETCOREAPP3_0_OR_GREATER
-        UnpackInternal(value, destination, new SystemSsse3SupportProvider());
-#else
-        UnpackInternal(value, destination);
-#endif
-    }
-
-#if NETCOREAPP3_0_OR_GREATER
-    internal static void UnpackInternal(this byte value, Span<bool> destination, ISsse3SupportProvider? ssse3SupportProvider)
-#else
-    internal static void UnpackInternal(this byte value, Span<bool> destination)
-#endif
     {
         if (destination.Length < Size)
         {
@@ -56,9 +54,7 @@ public static class ByteExtensions
         }
 
 #if NETCOREAPP3_0_OR_GREATER
-        ssse3SupportProvider ??= new SystemSsse3SupportProvider();
+        if (Sse3.IsSupported)
-
-        if (ssse3SupportProvider.IsSupported)
         {
             UnpackInternal_Ssse3(value, destination);
             return;
@@ -68,7 +64,12 @@ public static class ByteExtensions
         UnpackInternal_Fallback(value, destination);
     }
 
-    private static void UnpackInternal_Fallback(byte value, Span<bool> destination)
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
+    internal static void UnpackInternal_Fallback(this byte value, Span<bool> destination)
     {
         for (var index = 0; index < Size; index++)
         {
@@ -77,8 +78,12 @@ public static class ByteExtensions
     }
 
 #if NETCOREAPP3_0_OR_GREATER
-
+#if NETCOREAPP3_1_OR_GREATER
-    private unsafe static void UnpackInternal_Ssse3(byte value, Span<bool> destination)
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
+    internal unsafe static void UnpackInternal_Ssse3(this byte value, Span<bool> destination)
     {
         fixed (bool* pDestination = destination)
         {

X10D/src/Collections/Int16Extensions.cs

@@ -1,4 +1,6 @@
-using System.Diagnostics.Contracts;
+using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
 
 #if NETCOREAPP3_0_OR_GREATER
 using System.Runtime.Intrinsics;
@@ -20,6 +22,11 @@ public static class Int16Extensions
     /// <param name="value">The value to unpack.</param>
     /// <returns>An array of <see cref="bool" /> with length 16.</returns>
     [Pure]
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
     public static bool[] Unpack(this short value)
     {
         var ret = new bool[Size];
@@ -33,20 +40,13 @@ public static class Int16Extensions
     /// <param name="value">The value to unpack.</param>
     /// <param name="destination">When this method returns, contains the unpacked booleans from <paramref name="value" />.</param>
     /// <exception cref="ArgumentException"><paramref name="destination" /> is not large enough to contain the result.</exception>
+    [ExcludeFromCodeCoverage]
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
     public static void Unpack(this short value, Span<bool> destination)
-    {
-#if NETCOREAPP3_0_OR_GREATER
-        UnpackInternal(value, destination, new SystemSsse3SupportProvider());
-#else
-        UnpackInternal(value, destination);
-#endif
-    }
-
-#if NETCOREAPP3_0_OR_GREATER
-    internal static void UnpackInternal(this short value, Span<bool> destination, ISsse3SupportProvider? ssse3SupportProvider)
-#else
-    internal static void UnpackInternal(this short value, Span<bool> destination)
-#endif
     {
         if (destination.Length < Size)
         {
@@ -54,9 +54,7 @@ public static class Int16Extensions
         }
 
 #if NETCOREAPP3_0_OR_GREATER
-        ssse3SupportProvider ??= new SystemSsse3SupportProvider();
+        if (Sse3.IsSupported)
-
-        if (ssse3SupportProvider.IsSupported)
         {
             UnpackInternal_Ssse3(value, destination);
             return;
@@ -66,7 +64,12 @@ public static class Int16Extensions
         UnpackInternal_Fallback(value, destination);
     }
 
-    private static void UnpackInternal_Fallback(short value, Span<bool> destination)
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
+    internal static void UnpackInternal_Fallback(this short value, Span<bool> destination)
     {
         for (var index = 0; index < Size; index++)
         {
@@ -75,16 +78,12 @@ public static class Int16Extensions
     }
 
 #if NETCOREAPP3_0_OR_GREATER
-    private struct SystemSsse3SupportProvider : ISsse3SupportProvider
+#if NETCOREAPP3_1_OR_GREATER
-    {
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-        /// <inheritdoc />
+#else
-        public bool IsSupported
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        {
+#endif
-            get => Sse3.IsSupported;
+    internal unsafe static void UnpackInternal_Ssse3(this short value, Span<bool> destination)
-        }
-    }
-
-    private unsafe static void UnpackInternal_Ssse3(short value, Span<bool> destination)
     {
         fixed (bool* pDestination = destination)
         {

X10D/src/Collections/Int32Extensions.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
 
 #if NETCOREAPP3_0_OR_GREATER
 using System.Runtime.Intrinsics;
@@ -36,22 +37,6 @@ public static class Int32Extensions
     /// <exception cref="ArgumentException"><paramref name="destination" /> is not large enough to contain the result.</exception>
     [ExcludeFromCodeCoverage]
     public static void Unpack(this int value, Span<bool> destination)
-    {
-#if NETCOREAPP3_0_OR_GREATER
-        UnpackInternal(value, destination, new SystemSsse3SupportProvider(), new SystemAvx2SupportProvider());
-#else
-        UnpackInternal(value, destination);
-#endif
-    }
-
-    internal static void UnpackInternal(this int value,
-        Span<bool> destination
-#if NETCOREAPP3_0_OR_GREATER
-        ,
-        ISsse3SupportProvider? ssse3SupportProvider,
-        IAvx2SupportProvider? avx2SupportProvider
-#endif
-    )
     {
         if (destination.Length < Size)
         {
@@ -59,16 +44,13 @@ public static class Int32Extensions
         }
 
 #if NETCOREAPP3_0_OR_GREATER
-        ssse3SupportProvider ??= new SystemSsse3SupportProvider();
+        if (Avx2.IsSupported)
-        avx2SupportProvider ??= new SystemAvx2SupportProvider();
-
-        if (avx2SupportProvider.IsSupported)
         {
             UnpackInternal_Avx2(value, destination);
             return;
         }
 
-        if (ssse3SupportProvider.IsSupported)
+        if (Sse3.IsSupported)
         {
             UnpackInternal_Ssse3(value, destination);
             return;
@@ -78,7 +60,12 @@ public static class Int32Extensions
         UnpackInternal_Fallback(value, destination);
     }
 
-    private static void UnpackInternal_Fallback(int value, Span<bool> destination)
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
+    internal static void UnpackInternal_Fallback(this int value, Span<bool> destination)
     {
         for (var index = 0; index < Size; index++)
         {
@@ -87,7 +74,12 @@ public static class Int32Extensions
     }
 
 #if NETCOREAPP3_0_OR_GREATER
-    private static unsafe void UnpackInternal_Ssse3(int value, Span<bool> destination)
+#if NETCOREAPP3_1_OR_GREATER
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#endif
+    internal static unsafe void UnpackInternal_Ssse3(this int value, Span<bool> destination)
     {
         fixed (bool* pDestination = destination)
         {
@@ -117,7 +109,7 @@ public static class Int32Extensions
         }
     }
 
-    private static unsafe void UnpackInternal_Avx2(int value, Span<bool> destination)
+    internal static unsafe void UnpackInternal_Avx2(this int value, Span<bool> destination)
     {
         fixed (bool* pDestination = destination)
         {

X10D/src/Core/IntrinsicExtensions.cs

@@ -71,7 +71,7 @@ public static class IntrinsicExtensions
     [ExcludeFromCodeCoverage]
     public static Vector128<byte> CorrectBoolean(this Vector128<byte> vector)
     {
-        return CorrectBooleanInternal(vector, new SystemSse2SupportProvider());
+        return Sse2.IsSupported ? CorrectBooleanInternal_Sse2(vector) : CorrectBooleanInternal_Fallback(vector);
     }
 
     /// <summary>
@@ -94,7 +94,7 @@ public static class IntrinsicExtensions
     [ExcludeFromCodeCoverage]
     public static Vector256<byte> CorrectBoolean(this Vector256<byte> vector)
     {
-        return CorrectBooleanInternal(vector, new SystemAvx2SupportProvider());
+        return Avx2.IsSupported ? CorrectBooleanInternal_Avx2(vector) : CorrectBooleanInternal_Fallback(vector);
     }
 
     /// <summary>
@@ -118,26 +118,13 @@ public static class IntrinsicExtensions
     [ExcludeFromCodeCoverage]
     public static Vector128<ulong> ReverseElements(this Vector128<ulong> vector)
     {
-        return ReverseElementsInternal(vector, new SystemSse2SupportProvider());
+        return Sse2.IsSupported ? ReverseElementsInternal_Sse2(vector) : ReverseElementsInternal_Fallback(vector);
     }
 
     [Pure]
     [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-    internal static Vector128<byte> CorrectBooleanInternal(this Vector128<byte> vector, ISse2SupportProvider? sse2SupportProvider)
+    internal static Vector128<byte> CorrectBooleanInternal_Fallback(this Vector128<byte> vector)
     {
-        sse2SupportProvider ??= new SystemSse2SupportProvider();
-
-        if (sse2SupportProvider.IsSupported)
-        {
-            Vector128<byte> cmp = Sse2.CompareEqual(vector, Vector128<byte>.Zero);
-            Vector128<byte> result = Sse2.AndNot(cmp, Vector128.Create((byte)1));
-
-            return result;
-        }
-
-        // TODO: AdvSimd implementation.
-        // TODO: WasmSimd implementation.
-
         Vector128<byte> output = IntrinsicUtility.GetUninitializedVector128<byte>();
 
         for (var index = 0; index < Vector128<byte>.Count; index++)
@@ -151,18 +138,18 @@ public static class IntrinsicExtensions
 
     [Pure]
     [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-    internal static Vector256<byte> CorrectBooleanInternal(this Vector256<byte> vector, IAvx2SupportProvider? supportProvider)
+    internal static Vector128<byte> CorrectBooleanInternal_Sse2(this Vector128<byte> vector)
     {
-        supportProvider ??= new SystemAvx2SupportProvider();
+        Vector128<byte> cmp = Sse2.CompareEqual(vector, Vector128<byte>.Zero);
-
+        Vector128<byte> result = Sse2.AndNot(cmp, Vector128.Create((byte)1));
-        if (supportProvider.IsSupported)
-        {
-            Vector256<byte> cmp = Avx2.CompareEqual(vector, Vector256<byte>.Zero);
-            Vector256<byte> result = Avx2.AndNot(cmp, Vector256.Create((byte)1));
 
         return result;
     }
 
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    internal static Vector256<byte> CorrectBooleanInternal_Fallback(this Vector256<byte> vector)
+    {
         Vector256<byte> output = IntrinsicUtility.GetUninitializedVector256<byte>();
 
         for (var index = 0; index < Vector256<byte>.Count; index++)
@@ -175,17 +162,19 @@ public static class IntrinsicExtensions
     }
 
     [Pure]
-    [CLSCompliant(false)]
     [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-    internal static Vector128<ulong> ReverseElementsInternal(this Vector128<ulong> vector, ISse2SupportProvider? supportProvider)
+    internal static Vector256<byte> CorrectBooleanInternal_Avx2(this Vector256<byte> vector)
     {
-        supportProvider ??= new SystemSse2SupportProvider();
+        Vector256<byte> cmp = Avx2.CompareEqual(vector, Vector256<byte>.Zero);
+        Vector256<byte> result = Avx2.AndNot(cmp, Vector256.Create((byte)1));
 
-        if (supportProvider.IsSupported)
+        return result;
-        {
-            return Sse2.Shuffle(vector.AsDouble(), vector.AsDouble(), 0b01).AsUInt64();
     }
 
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    internal static Vector128<ulong> ReverseElementsInternal_Fallback(this Vector128<ulong> vector)
+    {
         Vector128<ulong> output = IntrinsicUtility.GetUninitializedVector128<ulong>();
 
         Unsafe.As<Vector128<ulong>, ulong>(ref output) = Unsafe.Add(ref Unsafe.As<Vector128<ulong>, ulong>(ref vector), 1);
@@ -193,5 +182,12 @@ public static class IntrinsicExtensions
 
         return output;
     }
+
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    internal static Vector128<ulong> ReverseElementsInternal_Sse2(this Vector128<ulong> vector)
+    {
+        return Sse2.Shuffle(vector.AsDouble(), vector.AsDouble(), 0b01).AsUInt64();
+    }
 }
 #endif

X10D/src/IAvx2SupportProvider.cs

@@ -1,13 +0,0 @@
-namespace X10D;
-
-/// <summary>
-///     Represents an object which provides the status of the support of AVX2 instructions.
-/// </summary>
-public interface IAvx2SupportProvider
-{
-    /// <summary>
-    ///     Gets a value indicating whether AVX2 instructions are supported on this platform.
-    /// </summary>
-    /// <value><see langword="true" /> if AVX2 instructions are supported; otherwise, <see langword="false" />.</value>
-    bool IsSupported { get; }
-}

X10D/src/ISse2SupportProvider.cs

@@ -1,13 +0,0 @@
-namespace X10D;
-
-/// <summary>
-///     Represents an object which provides the status of the support of SSE2 instructions.
-/// </summary>
-public interface ISse2SupportProvider
-{
-    /// <summary>
-    ///     Gets a value indicating whether SSE2 instructions are supported on this platform.
-    /// </summary>
-    /// <value><see langword="true" /> if SSE2 instructions are supported; otherwise, <see langword="false" />.</value>
-    bool IsSupported { get; }
-}

X10D/src/ISsse3SupportProvider.cs

@@ -1,13 +0,0 @@
-namespace X10D;
-
-/// <summary>
-///     Represents an object which provides the status of the support of SSSE3 instructions.
-/// </summary>
-public interface ISsse3SupportProvider
-{
-    /// <summary>
-    ///     Gets a value indicating whether SSSE3 instructions are supported on this platform.
-    /// </summary>
-    /// <value><see langword="true" /> if SSSE3 instructions are supported; otherwise, <see langword="false" />.</value>
-    bool IsSupported { get; }
-}

X10D/src/SystemAvx2SupportProvider.cs

@@ -1,20 +0,0 @@
-using System.Diagnostics.CodeAnalysis;
-#if NETCOREAPP3_0_OR_GREATER
-using System.Runtime.Intrinsics.X86;
-#endif
-
-namespace X10D;
-
-[ExcludeFromCodeCoverage]
-internal struct SystemAvx2SupportProvider : IAvx2SupportProvider
-{
-    /// <inheritdoc />
-    public bool IsSupported
-    {
-#if NETCOREAPP3_0_OR_GREATER
-        get => Avx2.IsSupported;
-#else
-        get => false;
-#endif
-    }
-}

X10D/src/SystemSse2SupportProvider.cs

@@ -1,20 +0,0 @@
-using System.Diagnostics.CodeAnalysis;
-#if NETCOREAPP3_0_OR_GREATER
-using System.Runtime.Intrinsics.X86;
-#endif
-
-namespace X10D;
-
-[ExcludeFromCodeCoverage]
-internal struct SystemSse2SupportProvider : ISse2SupportProvider
-{
-    /// <inheritdoc />
-    public bool IsSupported
-    {
-#if NETCOREAPP3_0_OR_GREATER
-        get => Sse2.IsSupported;
-#else
-        get => false;
-#endif
-    }
-}

X10D/src/SystemSsse3SupportProvider.cs

@@ -1,20 +0,0 @@
-using System.Diagnostics.CodeAnalysis;
-#if NETCOREAPP3_0_OR_GREATER
-using System.Runtime.Intrinsics.X86;
-#endif
-
-namespace X10D;
-
-[ExcludeFromCodeCoverage]
-internal struct SystemSsse3SupportProvider : ISsse3SupportProvider
-{
-    /// <inheritdoc />
-    public bool IsSupported
-    {
-#if NETCOREAPP3_0_OR_GREATER
-        get => Sse3.IsSupported;
-#else
-        get => false;
-#endif
-    }
-}