Port RGB converter

Author: JimBobSquarePants

src/ImageSharp/Common/Helpers/SimdUtils.cs

@@ -40,17 +40,6 @@ internal static Vector4 PseudoRound(this Vector4 v)
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     internal static Vector<float> RoundToNearestInteger(this Vector<float> v)
     {
-        if (Avx512F.IsSupported && Vector<float>.Count == Vector512<float>.Count)
-        {
-            ref Vector512<float> v512 = ref Unsafe.As<Vector<float>, Vector512<float>>(ref v);
-
-            // imm8 = 0b1000:
-            //   imm8[7:4] = 0b0000 -> preserve 0 fractional bits (round to whole numbers)
-            //   imm8[3:0] = 0b1000 -> _MM_FROUND_TO_NEAREST_INT | _MM_FROUND_NO_EXC (round to nearest even, suppress exceptions)
-            Vector512<float> vRound = Avx512F.RoundScale(v512, 0b0000_1000);
-            return Unsafe.As<Vector512<float>, Vector<float>>(ref vRound);
-        }
-
         if (Avx2.IsSupported && Vector<float>.Count == Vector256<float>.Count)
         {
             ref Vector256<float> v256 = ref Unsafe.As<Vector<float>, Vector256<float>>(ref v);

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

@@ -14,13 +14,13 @@ public CmykScalar(int precision)
 
         /// <inheritdoc/>
         public override void ConvertToRgbInPlace(in ComponentValues values) =>
-            ConvertToRgbInplace(values, this.MaximumValue);
+            ConvertToRgbInPlace(values, this.MaximumValue);
 
         /// <inheritdoc/>
         public override void ConvertFromRgb(in ComponentValues values, Span<float> rLane, Span<float> gLane, Span<float> bLane)
             => ConvertFromRgb(values, this.MaximumValue, rLane, gLane, bLane);
 
-        public static void ConvertToRgbInplace(in ComponentValues values, float maxValue)
+        public static void ConvertToRgbInPlace(in ComponentValues values, float maxValue)
         {
             Span<float> c0 = values.Component0;
             Span<float> c1 = values.Component1;

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

@@ -52,7 +52,7 @@ protected override void ConvertFromRgbVectorized(in ComponentValues values, Span
 
         /// <inheritdoc/>
         protected override void ConvertToRgbInPlaceScalarRemainder(in ComponentValues values)
-             => CmykScalar.ConvertToRgbInplace(values, this.MaximumValue);
+             => CmykScalar.ConvertToRgbInPlace(values, this.MaximumValue);
 
         /// <inheritdoc/>
         protected override void ConvertFromRgbScalarRemainder(in ComponentValues values, Span<float> rLane, Span<float> gLane, Span<float> bLane)

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.CmykVector512.cs

@@ -0,0 +1,51 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    internal sealed class RgbVector128 : JpegColorConverterVector128
+    {
+        public RgbVector128(int precision)
+            : base(JpegColorSpace.RGB, precision)
+        {
+        }
+
+        /// <inheritdoc/>
+        public override void ConvertToRgbInPlace(in ComponentValues values)
+        {
+            ref Vector128<float> rBase =
+                ref Unsafe.As<float, Vector128<float>>(ref MemoryMarshal.GetReference(values.Component0));
+            ref Vector128<float> gBase =
+                ref Unsafe.As<float, Vector128<float>>(ref MemoryMarshal.GetReference(values.Component1));
+            ref Vector128<float> bBase =
+                ref Unsafe.As<float, Vector128<float>>(ref MemoryMarshal.GetReference(values.Component2));
+
+            // Used for the color conversion
+            Vector128<float> scale = Vector128.Create(1 / this.MaximumValue);
+            nuint n = values.Component0.Vector128Count<float>();
+            for (nuint i = 0; i < n; i++)
+            {
+                ref Vector128<float> r = ref Unsafe.Add(ref rBase, i);
+                ref Vector128<float> g = ref Unsafe.Add(ref gBase, i);
+                ref Vector128<float> b = ref Unsafe.Add(ref bBase, i);
+                r *= scale;
+                g *= scale;
+                b *= scale;
+            }
+        }
+
+        /// <inheritdoc/>
+        public override void ConvertFromRgb(in ComponentValues values, Span<float> rLane, Span<float> gLane, Span<float> bLane)
+        {
+            rLane.CopyTo(values.Component0);
+            gLane.CopyTo(values.Component1);
+            bLane.CopyTo(values.Component2);
+        }
+    }
+}

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

@@ -0,0 +1,51 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    internal sealed class RgbVector256 : JpegColorConverterVector256
+    {
+        public RgbVector256(int precision)
+            : base(JpegColorSpace.RGB, precision)
+        {
+        }
+
+        /// <inheritdoc/>
+        public override void ConvertToRgbInPlace(in ComponentValues values)
+        {
+            ref Vector256<float> rBase =
+                ref Unsafe.As<float, Vector256<float>>(ref MemoryMarshal.GetReference(values.Component0));
+            ref Vector256<float> gBase =
+                ref Unsafe.As<float, Vector256<float>>(ref MemoryMarshal.GetReference(values.Component1));
+            ref Vector256<float> bBase =
+                ref Unsafe.As<float, Vector256<float>>(ref MemoryMarshal.GetReference(values.Component2));
+
+            // Used for the color conversion
+            Vector256<float> scale = Vector256.Create(1 / this.MaximumValue);
+            nuint n = values.Component0.Vector256Count<float>();
+            for (nuint i = 0; i < n; i++)
+            {
+                ref Vector256<float> r = ref Unsafe.Add(ref rBase, i);
+                ref Vector256<float> g = ref Unsafe.Add(ref gBase, i);
+                ref Vector256<float> b = ref Unsafe.Add(ref bBase, i);
+                r *= scale;
+                g *= scale;
+                b *= scale;
+            }
+        }
+
+        /// <inheritdoc/>
+        public override void ConvertFromRgb(in ComponentValues values, Span<float> rLane, Span<float> gLane, Span<float> bLane)
+        {
+            rLane.CopyTo(values.Component0);
+            gLane.CopyTo(values.Component1);
+            bLane.CopyTo(values.Component2);
+        }
+    }
+}