unrelated to PR: Skipping AVX2-tests if the CPU does not support AVX2

src/ImageSharp/Common/Extensions/SimdUtils.cs

@@ -17,11 +17,11 @@ namespace SixLabors.ImageSharp
         /// <summary>
         /// Indicates AVX2 architecture where both float and integer registers are of size 256 byte.
         /// </summary>
-        public static readonly bool IsAvx2 = Vector<float>.Count == 8 && Vector<int>.Count == 8;
+        public static readonly bool IsAvx2CompatibleArchitecture = Vector<float>.Count == 8 && Vector<int>.Count == 8;
 
         internal static void GuardAvx2(string operation)
         {
-            if (!IsAvx2)
+            if (!IsAvx2CompatibleArchitecture)
             {
                 throw new NotSupportedException($"{operation} is supported only on AVX2 CPU!");
             }

src/ImageSharp/PixelFormats/Rgba32.PixelOperations.cs

@@ -120,7 +120,7 @@ namespace SixLabors.ImageSharp
             {
                 GuardSpans(sourceVectors, nameof(sourceVectors), destColors, nameof(destColors), count);
 
-                if (!SimdUtils.IsAvx2)
+                if (!SimdUtils.IsAvx2CompatibleArchitecture)
                 {
                     base.PackFromVector4(sourceVectors, destColors, count);
                     return;

tests/ImageSharp.Tests/Common/SimdUtilsTests.cs

@@ -109,6 +109,16 @@ namespace SixLabors.ImageSharp.Tests.Common
             AssertEvenRoundIsCorrect(r, v);
         }
 
+        private bool SkipOnNonAvx2([CallerMemberName] string testCaseName = null)
+        {
+            if (!SimdUtils.IsAvx2CompatibleArchitecture)
+            {
+                this.Output.WriteLine("Skipping AVX2 specific test case: " + testCaseName);
+                return true;
+            }
+            return false;
+        }
+
         [Theory]
         [InlineData(1, 0)]
         [InlineData(1, 8)]
@@ -116,6 +126,11 @@ namespace SixLabors.ImageSharp.Tests.Common
         [InlineData(3, 128)]
         public void BulkConvertNormalizedFloatToByte_WithRoundedData(int seed, int count)
         {
+            if (this.SkipOnNonAvx2())
+            {
+                return;
+            }
+
             float[] orig =  new Random(seed).GenerateRandomRoundedFloatArray(count, 0, 256);
             float[] normalized = orig.Select(f => f / 255f).ToArray();
 
@@ -135,6 +150,11 @@ namespace SixLabors.ImageSharp.Tests.Common
         [InlineData(3, 128)]
         public void BulkConvertNormalizedFloatToByte_WithNonRoundedData(int seed, int count)
         {
+            if (this.SkipOnNonAvx2())
+            {
+                return;
+            }
+
             float[] source = new Random(seed).GenerateRandomFloatArray(count, 0, 1f);
             
             byte[] dest = new byte[count];
@@ -155,6 +175,11 @@ namespace SixLabors.ImageSharp.Tests.Common
         [InlineData(3, 128)]
         public void BulkConvertNormalizedFloatToByteClampOverflows(int seed, int count)
         {
+            if (this.SkipOnNonAvx2())
+            {
+                return;
+            }
+
             float[] orig = new Random(seed).GenerateRandomRoundedFloatArray(count, -50, 444);
             float[] normalized = orig.Select(f => f / 255f).ToArray();
 
@@ -185,6 +210,11 @@ namespace SixLabors.ImageSharp.Tests.Common
         [Fact]
         private void BulkConvertNormalizedFloatToByte_Step()
         {
+            if (this.SkipOnNonAvx2())
+            {
+                return;
+            }
+
             float[] source = {0, 7, 42, 255, 0.5f, 1.1f, 2.6f, 16f};
             byte[] expected = source.Select(f => (byte)Math.Round(f)).ToArray();