Drop FromGrayscaleVector8

src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromGrayScaleVector8.cs

@@ -1,53 +0,0 @@
-// Copyright (c) Six Labors.
-// Licensed under the Apache License, Version 2.0.
-
-using System;
-using System.Numerics;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-using SixLabors.ImageSharp.Tuples;
-
-namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters
-{
-    internal abstract partial class JpegColorConverter
-    {
-        internal sealed class FromGrayscaleVector8 : Vector8JpegColorConverter
-        {
-            public FromGrayscaleVector8(int precision)
-                : base(JpegColorSpace.Grayscale, precision)
-            {
-            }
-
-            protected override void ConvertCoreVectorized(in ComponentValues values, Span<Vector4> result)
-            {
-                ref Vector<float> gBase =
-                    ref Unsafe.As<float, Vector<float>>(ref MemoryMarshal.GetReference(values.Component0));
-
-                ref Vector4Octet resultBase =
-                    ref Unsafe.As<Vector4, Vector4Octet>(ref MemoryMarshal.GetReference(result));
-
-                Vector4Pair gg = default;
-                ref Vector<float> ggRefAsVector = ref Unsafe.As<Vector4Pair, Vector<float>>(ref gg);
-
-                var scale = new Vector<float>(1 / this.MaximumValue);
-
-                // Walking 8 elements at one step:
-                int n = result.Length / 8;
-                for (int i = 0; i < n; i++)
-                {
-                    Vector<float> g = Unsafe.Add(ref gBase, i);
-                    g *= scale;
-
-                    ggRefAsVector = g;
-
-                    // Collect (g0,g1...g7) vector values in the expected (g0,g0,g0,1), (g1,g1,g1,1) ... order:
-                    ref Vector4Octet destination = ref Unsafe.Add(ref resultBase, i);
-                    destination.Pack(ref gg);
-                }
-            }
-
-            protected override void ConvertCore(in ComponentValues values, Span<Vector4> result) =>
-                FromGrayscaleBasic.ConvertCore(values, result, this.MaximumValue);
-        }
-    }
-}

src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.cs

@@ -141,7 +141,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters
         private static IEnumerable<JpegColorConverter> GetGrayScaleConverters(int precision)
         {
             yield return new FromGrayscaleAvx2(precision);
-            yield return new FromGrayscaleVector8(precision);
             yield return new FromGrayscaleBasic(precision);
         }
 

tests/ImageSharp.Benchmarks/Codecs/Jpeg/GrayscaleColorConversion.cs

@@ -19,14 +19,6 @@ namespace SixLabors.ImageSharp.Benchmarks.Codecs.Jpeg
             new JpegColorConverter.FromGrayscaleBasic(8).ConvertToRgba(values, this.output);
         }
 
-        [Benchmark]
-        public void SimdVector8()
-        {
-            var values = new JpegColorConverter.ComponentValues(this.input, 0);
-
-            new JpegColorConverter.FromGrayscaleVector8(8).ConvertToRgba(values, this.output);
-        }
-
         [Benchmark]
         public void SimdVectorAvx2()
         {

tests/ImageSharp.Tests/Formats/Jpg/JpegColorConverterTests.cs

@@ -184,24 +184,6 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
                 seed);
         }
 
-        [Theory]
-        [MemberData(nameof(CommonConversionData))]
-        public void FromGrayscaleVector8(int inputBufferLength, int resultBufferLength, int seed)
-        {
-            if (!SimdUtils.HasVector8)
-            {
-                this.Output.WriteLine("No AVX2 present, skipping test!");
-                return;
-            }
-
-            ValidateConversion(
-                new JpegColorConverter.FromGrayscaleVector8(8),
-                1,
-                inputBufferLength,
-                resultBufferLength,
-                seed);
-        }
-
         [Theory]
         [MemberData(nameof(CommonConversionData))]
         public void FromGrayscaleAvx2(int inputBufferLength, int resultBufferLength, int seed)