Optimized Block8x8F

Author: gfoidl

src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs

@@ -101,24 +101,17 @@ internal float this[nuint idx]
         set => this[((uint)y * 8) + (uint)x] = value;
     }
 
-    public static Block8x8F Load(Span<float> data)
-    {
-        Block8x8F result = default;
-        result.LoadFrom(data);
-        return result;
-    }
-
     /// <summary>
     /// Load raw 32bit floating point data from source.
     /// </summary>
-    /// <param name="source">Source</param>
+    /// <param name="data">Source</param>
     [MethodImpl(InliningOptions.ShortMethod)]
-    public void LoadFrom(Span<float> source)
+    public static Block8x8F Load(Span<float> data)
     {
-        ref byte s = ref Unsafe.As<float, byte>(ref MemoryMarshal.GetReference(source));
-        ref byte d = ref Unsafe.As<Block8x8F, byte>(ref this);
+        DebugGuard.MustBeGreaterThanOrEqualTo(data.Length, Size, "data is too small");
 
-        Unsafe.CopyBlock(ref d, ref s, Size * sizeof(float));
+        ref byte src = ref Unsafe.As<float, byte>(ref MemoryMarshal.GetReference(data));
+        return Unsafe.ReadUnaligned<Block8x8F>(ref src);
     }
 
     /// <summary>
@@ -144,10 +137,10 @@ public unsafe void LoadFrom(Span<int> source)
     [MethodImpl(InliningOptions.ShortMethod)]
     public unsafe void ScaledCopyTo(float[] dest)
     {
-        fixed (void* ptr = &this.V0L)
-        {
-            Marshal.Copy((IntPtr)ptr, dest, 0, Size);
-        }
+        DebugGuard.MustBeGreaterThanOrEqualTo(dest.Length, Size, "dest is too small");
+
+        ref byte destRef = ref Unsafe.As<float, byte>(ref MemoryMarshal.GetArrayDataReference(dest));
+        Unsafe.WriteUnaligned(ref destRef, this);
     }
 
     public float[] ToArray()

tests/ImageSharp.Benchmarks/Codecs/Jpeg/BlockOperations/Block8x8F_MultiplyInPlaceBlock.cs

@@ -29,8 +29,6 @@ private static Block8x8F Create8x8FloatData()
             }
         }
 
-        var source = default(Block8x8F);
-        source.LoadFrom(result);
-        return source;
+        return Block8x8F.Load(result);
     }
 }

tests/ImageSharp.Tests/Formats/Jpg/Block8x8FTests.cs

@@ -99,8 +99,7 @@ public void Load_Store_FloatArray()
             Times,
             () =>
             {
-                var b = default(Block8x8F);
-                b.LoadFrom(data);
+                Block8x8F b = Block8x8F.Load(data);
                 b.ScaledCopyTo(mirror);
             });
 
@@ -117,8 +116,7 @@ static void RunTest()
             float[] expected = Create8x8FloatData();
             ReferenceImplementations.Transpose8x8(expected);
 
-            var block8x8 = default(Block8x8F);
-            block8x8.LoadFrom(Create8x8FloatData());
+            Block8x8F block8x8 = Block8x8F.Load(Create8x8FloatData());
 
             block8x8.TransposeInplace();
 
@@ -153,9 +151,8 @@ private static float[] Create8x8ColorCropTestData()
     [Fact]
     public void NormalizeColors()
     {
-        var block = default(Block8x8F);
         float[] input = Create8x8ColorCropTestData();
-        block.LoadFrom(input);
+        Block8x8F block = Block8x8F.Load(input);
         this.Output.WriteLine("Input:");
         this.PrintLinearData(input);
 
@@ -242,8 +239,7 @@ public void RoundInto()
     {
         float[] data = Create8x8RandomFloatData(-1000, 1000);
 
-        var source = default(Block8x8F);
-        source.LoadFrom(data);
+        Block8x8F source = Block8x8F.Load(data);
         var dest = default(Block8x8);
 
         source.RoundInto(ref dest);

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

@@ -114,8 +114,7 @@ static void RunTest(string serialized)
                 int seed = FeatureTestRunner.Deserialize<int>(serialized);
 
                 Span<float> src = Create8x8RandomFloatData(MinInputValue, MaxInputValue, seed);
-                var srcBlock = default(Block8x8F);
-                srcBlock.LoadFrom(src);
+                Block8x8F srcBlock = Block8x8F.Load(src);
 
                 float[] expectedDest = new float[64];
                 float[] temp = new float[64];
@@ -162,8 +161,7 @@ static void RunTest(string serialized)
         public void TranformIDCT_4x4(int seed)
         {
             Span<float> src = Create8x8RandomFloatData(MinInputValue, MaxInputValue, seed, 4, 4);
-            var srcBlock = default(Block8x8F);
-            srcBlock.LoadFrom(src);
+            Block8x8F srcBlock = Block8x8F.Load(src);
 
             float[] expectedDest = new float[64];
             float[] temp = new float[64];
@@ -224,8 +222,7 @@ static void AssertScaledElementEquality(Span<float> expected, Span<float> actual
         public void TranformIDCT_2x2(int seed)
         {
             Span<float> src = Create8x8RandomFloatData(MinInputValue, MaxInputValue, seed, 2, 2);
-            var srcBlock = default(Block8x8F);
-            srcBlock.LoadFrom(src);
+            Block8x8F srcBlock = Block8x8F.Load(src);
 
             float[] expectedDest = new float[64];
             float[] temp = new float[64];
@@ -286,8 +283,7 @@ static void AssertScaledElementEquality(Span<float> expected, Span<float> actual
         public void TranformIDCT_1x1(int seed)
         {
             Span<float> src = Create8x8RandomFloatData(MinInputValue, MaxInputValue, seed, 1, 1);
-            var srcBlock = default(Block8x8F);
-            srcBlock.LoadFrom(src);
+            Block8x8F srcBlock = Block8x8F.Load(src);
 
             float[] expectedDest = new float[64];
             float[] temp = new float[64];
@@ -330,8 +326,7 @@ static void RunTest(string serialized)
                 int seed = FeatureTestRunner.Deserialize<int>(serialized);
 
                 Span<float> src = Create8x8RandomFloatData(MinInputValue, MaxInputValue, seed);
-                var block = default(Block8x8F);
-                block.LoadFrom(src);
+                Block8x8F block = Block8x8F.Load(src);
 
                 float[] expectedDest = new float[64];
                 float[] temp1 = new float[64];

tests/ImageSharp.Tests/Formats/Jpg/ReferenceImplementationsTests.AccurateDCT.cs

@@ -25,8 +25,7 @@ public void ForwardThenInverse(int seed)
         {
             float[] data = Create8x8RandomFloatData(-1000, 1000, seed);
 
-            var b0 = default(Block8x8F);
-            b0.LoadFrom(data);
+            Block8x8F b0 = Block8x8F.Load(data);
 
             Block8x8F b1 = ReferenceImplementations.AccurateDCT.TransformFDCT(ref b0);
             Block8x8F b2 = ReferenceImplementations.AccurateDCT.TransformIDCT(ref b1);

tests/ImageSharp.Tests/Formats/Jpg/ReferenceImplementationsTests.FastFloatingPointDCT.cs

@@ -70,8 +70,7 @@ public void LLM_FDCT_IsEquivalentTo_AccurateImplementation(int seed)
         {
             float[] floatData = Create8x8RandomFloatData(-1000, 1000);
 
-            Block8x8F source = default;
-            source.LoadFrom(floatData);
+            Block8x8F source = Block8x8F.Load(floatData);
 
             Block8x8F expected = ReferenceImplementations.AccurateDCT.TransformFDCT(ref source);
             Block8x8F actual = ReferenceImplementations.LLM_FloatingPoint_DCT.TransformFDCT_UpscaleBy8(ref source);

tests/ImageSharp.Tests/Formats/Jpg/Utils/ReferenceImplementations.LLM_FloatingPoint_DCT.cs

@@ -36,8 +36,7 @@ public static Block8x8F TransformIDCT(ref Block8x8F source)
             float[] temp = new float[64];
 
             IDCT2D_llm(s, d, temp);
-            Block8x8F result = default;
-            result.LoadFrom(d);
+            Block8x8F result = Block8x8F.Load(d);
             return result;
         }
 
@@ -49,8 +48,7 @@ public static Block8x8F TransformFDCT_UpscaleBy8(ref Block8x8F source)
             float[] temp = new float[64];
 
             FDCT2D_llm(s, d, temp);
-            Block8x8F result = default;
-            result.LoadFrom(d);
+            Block8x8F result = Block8x8F.Load(d);
             return result;
         }