test: bring coverage to 100% for integer Unpack (#70)

X10D.Tests/src/Collections/ByteTests.cs

@@ -1,4 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
 using X10D.Collections;
 
 namespace X10D.Tests.Collections;
@@ -7,7 +8,7 @@ namespace X10D.Tests.Collections;
 public class ByteTests
 {
     [TestMethod]
-    public void UnpackBits_ShouldUnpackToArrayCorrectly()
+    public void Unpack_ShouldUnpackToArrayCorrectly()
     {
         bool[] bits = ((byte)0b11010100).Unpack();
 
@@ -24,7 +25,7 @@ public class ByteTests
     }
 
     [TestMethod]
-    public void UnpackBits_ShouldUnpackToSpanCorrectly()
+    public void Unpack_ShouldUnpackToSpanCorrectly()
     {
         Span<bool> bits = stackalloc bool[8];
         ((byte)0b11010100).Unpack(bits);
@@ -39,14 +40,35 @@ public class ByteTests
         Assert.IsTrue(bits[7]);
     }
 
+#if NET5_0_OR_GREATER
     [TestMethod]
-    public void UnpackBits_ShouldRepackEqually()
+    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallbackImplementation()
+    {
+        var mock = new Mock<ISsse3SupportProvider>();
+        mock.Setup(provider => provider.IsSupported).Returns(false);
+
+        Span<bool> bits = stackalloc bool[8];
+        ((byte)0b11010100).UnpackInternal(bits, mock.Object);
+
+        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]);
+    }
+#endif
+
+    [TestMethod]
+    public void Unpack_ShouldRepackEqually()
     {
         Assert.AreEqual(0b11010100, ((byte)0b11010100).Unpack().PackByte());
     }
 
     [TestMethod]
-    public void UnpackBits_ShouldThrow_GivenTooSmallSpan()
+    public void Unpack_ShouldThrow_GivenTooSmallSpan()
     {
         Assert.ThrowsException<ArgumentException>(() =>
         {

X10D.Tests/src/Collections/Int16Tests.cs

@@ -1,4 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
 using X10D.Collections;
 
 namespace X10D.Tests.Collections;
@@ -7,7 +8,7 @@ namespace X10D.Tests.Collections;
 public class Int16Tests
 {
     [TestMethod]
-    public void UnpackBits_ShouldUnpackToArrayCorrectly()
+    public void Unpack_ShouldUnpackToArrayCorrectly()
     {
         bool[] bits = ((short)0b11010100).Unpack();
 
@@ -29,7 +30,7 @@ public class Int16Tests
     }
 
     [TestMethod]
-    public void UnpackBits_ShouldUnpackToSpanCorrectly()
+    public void Unpack_ShouldUnpackToSpanCorrectly()
     {
         Span<bool> bits = stackalloc bool[16];
         ((short)0b11010100).Unpack(bits);
@@ -49,14 +50,40 @@ public class Int16Tests
         }
     }
 
+#if NET5_0_OR_GREATER
     [TestMethod]
-    public void UnpackBits_ShouldRepackEqually()
+    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallbackImplementation()
+    {
+        var mock = new Mock<ISsse3SupportProvider>();
+        mock.Setup(provider => provider.IsSupported).Returns(false);
+
+        Span<bool> bits = stackalloc bool[16];
+        ((short)0b11010100).UnpackInternal(bits, mock.Object);
+
+        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]);
+        }
+    }
+#endif
+
+    [TestMethod]
+    public void Unpack_ShouldRepackEqually()
     {
         Assert.AreEqual(0b11010100, ((short)0b11010100).Unpack().PackInt16());
     }
 
     [TestMethod]
-    public void UnpackBits_ShouldThrow_GivenTooSmallSpan()
+    public void Unpack_ShouldThrow_GivenTooSmallSpan()
     {
         Assert.ThrowsException<ArgumentException>(() =>
         {

X10D.Tests/src/Collections/Int32Tests.cs

@@ -1,4 +1,5 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
 using X10D.Collections;
 
 namespace X10D.Tests.Collections;
@@ -7,7 +8,7 @@ namespace X10D.Tests.Collections;
 public class Int32Tests
 {
     [TestMethod]
-    public void UnpackBits_ShouldUnpackToArrayCorrectly()
+    public void Unpack_ShouldUnpackToArrayCorrectly()
     {
         bool[] bits = 0b11010100.Unpack();
 
@@ -29,7 +30,7 @@ public class Int32Tests
     }
 
     [TestMethod]
-    public void UnpackBits_ShouldUnpackToSpanCorrectly()
+    public void Unpack_ShouldUnpackToSpanCorrectly()
     {
         Span<bool> bits = stackalloc bool[32];
         0b11010100.Unpack(bits);
@@ -49,14 +50,69 @@ public class Int32Tests
         }
     }
 
+#if NET5_0_OR_GREATER
     [TestMethod]
-    public void UnpackBits_ShouldRepackEqually()
+    public void Unpack_ShouldUnpackToSpanCorrectly_GivenFallbackFromAvx2()
+    {
+        var ssse3Mock = new Mock<ISsse3SupportProvider>();
+        var avx2Mock = new Mock<IAvx2SupportProvider>();
+        avx2Mock.Setup(provider => provider.IsSupported).Returns(false);
+        ssse3Mock.Setup(provider => provider.IsSupported).Returns(true);
+
+        Span<bool> bits = stackalloc bool[32];
+        0b11010100.UnpackInternal(bits, ssse3Mock.Object, avx2Mock.Object);
+
+        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 Unpack_ShouldUnpackToSpanCorrectly_GivenFallback()
+    {
+        var ssse3Mock = new Mock<ISsse3SupportProvider>();
+        var avx2Mock = new Mock<IAvx2SupportProvider>();
+        ssse3Mock.Setup(provider => provider.IsSupported).Returns(false);
+        avx2Mock.Setup(provider => provider.IsSupported).Returns(false);
+
+        Span<bool> bits = stackalloc bool[32];
+        0b11010100.UnpackInternal(bits, ssse3Mock.Object, avx2Mock.Object);
+
+        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]);
+        }
+    }
+
+#endif
+
+    [TestMethod]
+    public void Unpack_ShouldRepackEqually()
     {
         Assert.AreEqual(0b11010100, 0b11010100.Unpack().PackInt32());
     }
 
     [TestMethod]
-    public void UnpackBits_ShouldThrow_GivenTooSmallSpan()
+    public void Unpack_ShouldThrow_GivenTooSmallSpan()
     {
         Assert.ThrowsException<ArgumentException>(() =>
         {

X10D/src/Collections/ByteExtensions.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics.Contracts;
+using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.Contracts;
 
 #if NETCOREAPP3_0_OR_GREATER
 using System.Runtime.Intrinsics;
@@ -33,50 +34,68 @@ public static class ByteExtensions
     /// <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]
     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)
         {
-            throw new ArgumentException($"Destination must be at least {Size} in length.", nameof(destination));
+            throw new ArgumentException(ExceptionMessages.DestinationSpanLengthTooShort, nameof(destination));
         }
 
 #if NETCOREAPP3_0_OR_GREATER
-        if (Ssse3.IsSupported)
+        ssse3SupportProvider ??= new SystemSsse3SupportProvider();
+
+        if (ssse3SupportProvider.IsSupported)
         {
-            Ssse3Implementation(value, destination);
+            UnpackInternal_Ssse3(value, destination);
             return;
         }
 #endif
 
-        FallbackImplementation(value, destination);
+        UnpackInternal_Fallback(value, destination);
+    }
 
-#if NETCOREAPP3_0_OR_GREATER
+    private static void UnpackInternal_Fallback(byte value, Span<bool> destination)
-        unsafe static void Ssse3Implementation(byte value, Span<bool> destination)
+    {
+        for (var index = 0; index < Size; index++)
         {
-            fixed (bool* pDestination = destination)
+            destination[index] = (value & (1 << index)) != 0;
-            {
-                var mask2 = Vector128.Create(
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
-                );
-                var mask1 = Vector128.Create((byte)0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1);
-
-                Vector128<byte> vec = Vector128.Create(value).AsByte();
-                Vector128<byte> shuffle = Ssse3.Shuffle(vec, mask1);
-                Vector128<byte> and = Sse2.AndNot(shuffle, mask2);
-                Vector128<byte> cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
-                Vector128<byte> correctness = Sse2.And(cmp, Vector128.Create((byte)0x01));
-
-                Sse2.StoreScalar((long*)pDestination, correctness.AsInt64());
-            }
-        }
-#endif
-        static void FallbackImplementation(byte value, Span<bool> destination)
-        {
-            for (var index = 0; index < Size; index++)
-            {
-                destination[index] = (value & (1 << index)) != 0;
-            }
         }
     }
+
+#if NETCOREAPP3_0_OR_GREATER
+
+    private unsafe static void UnpackInternal_Ssse3(byte value, Span<bool> destination)
+    {
+        fixed (bool* pDestination = destination)
+        {
+            var mask2 = Vector128.Create(
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
+            );
+            var mask1 = Vector128.Create((byte)0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1);
+
+            Vector128<byte> vec = Vector128.Create(value).AsByte();
+            Vector128<byte> shuffle = Ssse3.Shuffle(vec, mask1);
+            Vector128<byte> and = Sse2.AndNot(shuffle, mask2);
+            Vector128<byte> cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
+            Vector128<byte> correctness = Sse2.And(cmp, Vector128.Create((byte)0x01));
+
+            Sse2.StoreScalar((long*)pDestination, correctness.AsInt64());
+        }
+    }
+#endif
 }

X10D/src/Collections/Int16Extensions.cs

@@ -34,51 +34,76 @@ public static class Int16Extensions
     /// <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>
     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)
         {
-            throw new ArgumentException($"Destination must be at least {Size} in length.", nameof(destination));
+            throw new ArgumentException(ExceptionMessages.DestinationSpanLengthTooShort, nameof(destination));
         }
 
 #if NETCOREAPP3_0_OR_GREATER
-        if (Ssse3.IsSupported)
+        ssse3SupportProvider ??= new SystemSsse3SupportProvider();
+
+        if (ssse3SupportProvider.IsSupported)
         {
-            Ssse3Implementation(value, destination);
+            UnpackInternal_Ssse3(value, destination);
             return;
         }
 #endif
 
-        FallbackImplementation(value, destination);
+        UnpackInternal_Fallback(value, destination);
+    }
 
-#if NETCOREAPP3_0_OR_GREATER
+    private static void UnpackInternal_Fallback(short value, Span<bool> destination)
-        unsafe static void Ssse3Implementation(short value, Span<bool> destination)
+    {
+        for (var index = 0; index < Size; index++)
         {
-            fixed (bool* pDestination = destination)
+            destination[index] = (value & (1 << index)) != 0;
-            {
-                var mask2 = Vector128.Create(
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
-                );
-                var mask1Lo = Vector128.Create((byte)0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1);
-
-                var one = Vector128.Create((byte)0x01);
-
-                var vec = Vector128.Create(value).AsByte();
-                var shuffle = Ssse3.Shuffle(vec, mask1Lo);
-                var and = Sse2.AndNot(shuffle, mask2);
-                var cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
-                var correctness = Sse2.And(cmp, one);
-
-                Sse2.Store((byte*)pDestination, correctness);
-            }
-        }
-#endif
-        static void FallbackImplementation(short value, Span<bool> destination)
-        {
-            for (var index = 0; index < Size; index++)
-            {
-                destination[index] = (value & (1 << index)) != 0;
-            }
         }
     }
+
+#if NETCOREAPP3_0_OR_GREATER
+    private struct SystemSsse3SupportProvider : ISsse3SupportProvider
+    {
+        /// <inheritdoc />
+        public bool IsSupported
+        {
+            get => Sse3.IsSupported;
+        }
+    }
+
+    private unsafe static void UnpackInternal_Ssse3(short value, Span<bool> destination)
+    {
+        fixed (bool* pDestination = destination)
+        {
+            var mask2 = Vector128.Create(
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
+            );
+
+            var mask1Lo = Vector128.Create((byte)0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1);
+            var one = Vector128.Create((byte)0x01);
+
+            Vector128<byte> vec = Vector128.Create(value).AsByte();
+            Vector128<byte> shuffle = Ssse3.Shuffle(vec, mask1Lo);
+            Vector128<byte> and = Sse2.AndNot(shuffle, mask2);
+            Vector128<byte> cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
+            Vector128<byte> correctness = Sse2.And(cmp, one);
+
+            Sse2.Store((byte*)pDestination, correctness);
+        }
+    }
+#endif
 }

X10D/src/Collections/Int32Extensions.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics.Contracts;
+using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.Contracts;
 
 #if NETCOREAPP3_0_OR_GREATER
 using System.Runtime.Intrinsics;
@@ -33,96 +34,114 @@ public static class Int32Extensions
     /// <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]
     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)
         {
-            throw new ArgumentException($"Destination must be at least {Size} in length.", nameof(destination));
+            throw new ArgumentException(ExceptionMessages.DestinationSpanLengthTooShort, nameof(destination));
         }
 
 #if NETCOREAPP3_0_OR_GREATER
-        // TODO: AdvSimd support.
+        ssse3SupportProvider ??= new SystemSsse3SupportProvider();
+        avx2SupportProvider ??= new SystemAvx2SupportProvider();
 
-        // https://stackoverflow.com/questions/24225786/fastest-way-to-unpack-32-bits-to-a-32-byte-simd-vector
+        if (avx2SupportProvider.IsSupported)
-        if (Avx2.IsSupported)
         {
-            Avx2Implementation(value, destination);
+            UnpackInternal_Avx2(value, destination);
             return;
         }
 
-        if (Ssse3.IsSupported)
+        if (ssse3SupportProvider.IsSupported)
         {
-            Ssse3Implementation(value, destination);
+            UnpackInternal_Ssse3(value, destination);
             return;
         }
 #endif
 
-        FallbackImplementation(value, destination);
+        UnpackInternal_Fallback(value, destination);
+    }
 
-#if NETCOREAPP3_0_OR_GREATER
+    private static void UnpackInternal_Fallback(int value, Span<bool> destination)
-        unsafe static void Avx2Implementation(int value, Span<bool> destination)
+    {
+        for (var index = 0; index < Size; index++)
         {
-            fixed (bool* pDestination = destination)
+            destination[index] = (value & (1 << index)) != 0;
-            {
-                var mask1 = Vector256.Create(
-                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-                    0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
-                    0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
-                    0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03
-                ).AsByte();
-                var mask2 = Vector256.Create(
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
-                );
-
-                var vec = Vector256.Create(value).AsByte();
-                var shuffle = Avx2.Shuffle(vec, mask1);
-                var and = Avx2.AndNot(shuffle, mask2);
-                var cmp = Avx2.CompareEqual(and, Vector256<byte>.Zero);
-                var correctness = Avx2.And(cmp, Vector256.Create((byte)0x01));
-
-                Avx.Store((byte*)pDestination, correctness);
-            }
-        }
-
-        unsafe static void Ssse3Implementation(int value, Span<bool> destination)
-        {
-            fixed (bool* pDestination = destination)
-            {
-                var mask2 = Vector128.Create(
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
-                    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
-                );
-                var mask1Lo = Vector128.Create((byte)0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1);
-                var mask1Hi = Vector128.Create((byte)2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3);
-
-                var one = Vector128.Create((byte)0x01);
-
-                var vec = Vector128.Create(value).AsByte();
-                var shuffle = Ssse3.Shuffle(vec, mask1Lo);
-                var and = Sse2.AndNot(shuffle, mask2);
-                var cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
-                var correctness = Sse2.And(cmp, one);
-
-                Sse2.Store((byte*)pDestination, correctness);
-
-                shuffle = Ssse3.Shuffle(vec, mask1Hi);
-                and = Sse2.AndNot(shuffle, mask2);
-                cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
-                correctness = Sse2.And(cmp, one);
-
-                Sse2.Store((byte*)pDestination + 16, correctness);
-            }
-        }
-#endif
-        static void FallbackImplementation(int value, Span<bool> destination)
-        {
-            for (var index = 0; index < Size; index++)
-            {
-                destination[index] = (value & (1 << index)) != 0;
-            }
         }
     }
+
+#if NETCOREAPP3_0_OR_GREATER
+    private static unsafe void UnpackInternal_Ssse3(int value, Span<bool> destination)
+    {
+        fixed (bool* pDestination = destination)
+        {
+            var mask2 = Vector128.Create(
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
+            );
+            var mask1Lo = Vector128.Create((byte)0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1);
+            var mask1Hi = Vector128.Create((byte)2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3);
+
+            var one = Vector128.Create((byte)0x01);
+
+            Vector128<byte> vec = Vector128.Create(value).AsByte();
+            Vector128<byte> shuffle = Ssse3.Shuffle(vec, mask1Lo);
+            Vector128<byte> and = Sse2.AndNot(shuffle, mask2);
+            Vector128<byte> cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
+            Vector128<byte> correctness = Sse2.And(cmp, one);
+
+            Sse2.Store((byte*)pDestination, correctness);
+
+            shuffle = Ssse3.Shuffle(vec, mask1Hi);
+            and = Sse2.AndNot(shuffle, mask2);
+            cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
+            correctness = Sse2.And(cmp, one);
+
+            Sse2.Store((byte*)pDestination + 16, correctness);
+        }
+    }
+
+    private static unsafe void UnpackInternal_Avx2(int value, Span<bool> destination)
+    {
+        fixed (bool* pDestination = destination)
+        {
+            var mask1 = Vector256.Create(
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+                0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
+                0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03
+            ).AsByte();
+            var mask2 = Vector256.Create(
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
+                0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
+            );
+
+            Vector256<byte> vec = Vector256.Create(value).AsByte();
+            Vector256<byte> shuffle = Avx2.Shuffle(vec, mask1);
+            Vector256<byte> and = Avx2.AndNot(shuffle, mask2);
+            Vector256<byte> cmp = Avx2.CompareEqual(and, Vector256<byte>.Zero);
+            Vector256<byte> correctness = Avx2.And(cmp, Vector256.Create((byte)0x01));
+
+            Avx.Store((byte*)pDestination, correctness);
+        }
+    }
+#endif
 }

X10D/src/Collections/Int64Extensions.cs

@@ -32,7 +32,7 @@ public static class Int64Extensions
     {
         if (destination.Length < Size)
         {
-            throw new ArgumentException($"Destination must be at least {Size} in length.", nameof(destination));
+            throw new ArgumentException(ExceptionMessages.DestinationSpanLengthTooShort, nameof(destination));
         }
 
         for (var index = 0; index < Size; index++)

X10D/src/ExceptionMessages.Designer.cs

@@ -1,7 +1,6 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Runtime Version:4.0.30319.42000
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.
@@ -87,6 +86,15 @@ namespace X10D {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to The destination span is too short to contain the data..
+        /// </summary>
+        internal static string DestinationSpanLengthTooShort {
+            get {
+                return ResourceManager.GetString("DestinationSpanLengthTooShort", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to The end index must be less than the list count..
         /// </summary>

X10D/src/ExceptionMessages.resx

@@ -123,6 +123,9 @@
   <data name="CountMustBeInRange" xml:space="preserve">
     <value>Count must be positive and count must refer to a location within the string/array/collection.</value>
   </data>
+  <data name="DestinationSpanLengthTooShort" xml:space="preserve">
+    <value>The destination span is too short to contain the data.</value>
+  </data>
   <data name="EndIndexLessThanStartIndex" xml:space="preserve">
     <value>The end index must be greater than or equal to the start index.</value>
   </data>

X10D/src/IAvx2SupportProvider.cs

@@ -0,0 +1,13 @@
+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/ISsse3SupportProvider.cs

@@ -0,0 +1,13 @@
+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

@@ -0,0 +1,18 @@
+#if NETCOREAPP3_0_OR_GREATER
+using System.Runtime.Intrinsics.X86;
+#endif
+
+namespace X10D;
+
+internal struct SystemAvx2SupportProvider : IAvx2SupportProvider
+{
+    /// <inheritdoc />
+    public bool IsSupported
+    {
+#if NETCOREAPP3_0_OR_GREATER
+        get => Avx2.IsSupported;
+#else
+        get => false;
+#endif
+    }
+}

X10D/src/SystemSsse3SupportProvider.cs

@@ -0,0 +1,18 @@
+#if NETCOREAPP3_0_OR_GREATER
+using System.Runtime.Intrinsics.X86;
+#endif
+
+namespace X10D;
+
+internal struct SystemSsse3SupportProvider : ISsse3SupportProvider
+{
+    /// <inheritdoc />
+    public bool IsSupported
+    {
+#if NETCOREAPP3_0_OR_GREATER
+        get => Sse3.IsSupported;
+#else
+        get => false;
+#endif
+    }
+}