more cleaning and adding some benchmark results. (#43)

* more cleaning and adding some benchmark results.

* Update Benchmark.cs

Author: lemire

README.md

@@ -7,7 +7,9 @@ This is a fast C# library to validate UTF-8 strings.
 ## Motivation
 
 We seek to speed up the `Utf8Utility.GetPointerToFirstInvalidByte` function from the C# runtime library.
-[The function is private in the Microsoft Runtime](https://github.com/dotnet/runtime/blob/4d709cd12269fcbb3d0fccfb2515541944475954/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Validation.cs), but we can expose it manually.
+[The function is private in the Microsoft Runtime](https://github.com/dotnet/runtime/blob/4d709cd12269fcbb3d0fccfb2515541944475954/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Validation.cs), but we can expose it manually. The C# runtime 
+function is well optimized and it makes use of advanced CPU instructions. Nevertheless, we propose
+an alternative that can be several times faster.
 
 Specifically, we provide the function `SimdUnicode.UTF8.GetPointerToFirstInvalidByte` which is a faster
 drop-in replacement:
@@ -35,7 +37,7 @@ We apply the algorithm used by Node.js, Bun, Oracle GraalVM, by the PHP interpre
 
 ## Requirements
 
-We recommend you install .NET 8: https://dotnet.microsoft.com/en-us/download/dotnet/8.0
+We recommend you install .NET 8 or better: https://dotnet.microsoft.com/en-us/download/dotnet/8.0
 
 
 ## Running tests
@@ -74,8 +76,6 @@ Or to target specific categories:
 dotnet test --filter "Category=scalar"
 ```
 
-
-
 ## Running Benchmarks
 
 To run the benchmarks, run the following command:
@@ -98,6 +98,28 @@ cd benchmark
 sudo dotnet run -c Release
 ```
 
+## Results (x64)
+
+To be completed.
+
+## Results (ARM)
+
+On an Apple M2 system, our validation function is two to three times
+faster than the standard library.
+
+| data set      | SimdUnicode speed (GB/s) | .NET speed (GB/s) |
+|:----------------|:-----------|:--------------------------|
+| Arabic-Lipsum   |  6.7       | 3.5                       |
+| Chinese-Lipsum  |  6.7       | 4.8                       |
+| Emoji-Lipsum    |  6.7       | 2.5                       |
+| Hebrew-Lipsum   |  6.7       | 3.5                       |
+| Hindi-Lipsum    |  6.8       | 3.0                       |
+| Japanese-Lipsum |  6.8       | 4.6                       |
+| Korean-Lipsum   |  6.6       | 1.8                       |
+| Latin-Lipsum    |  87        | 38                        |
+| Russian-Lipsum  |  6.7       | 2.6                       |
+
+
 ## Building the library
 
 ```
@@ -139,7 +161,7 @@ You can print the content of a vector register like so:
 
 ## More reading 
 
-- https://github.com/dotnet/coreclr/pull/21948/files#diff-2a22774bd6bff8e217ecbb3a41afad033ce0ca0f33645e9d8f5bdf7c9e3ac248
+- [Add optimized UTF-8 validation and transcoding apis, hook them up to UTF8Encoding](https://github.com/dotnet/coreclr/pull/21948/files#diff-2a22774bd6bff8e217ecbb3a41afad033ce0ca0f33645e9d8f5bdf7c9e3ac248)
 - https://github.com/dotnet/runtime/issues/41699
 - https://learn.microsoft.com/en-us/dotnet/standard/design-guidelines/
 - https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/coding-style/coding-conventions

benchmark/Benchmark.cs

@@ -5,6 +5,7 @@
 using BenchmarkDotNet.Configs;
 using BenchmarkDotNet.Reports;
 using BenchmarkDotNet.Filters;
+using BenchmarkDotNet.Jobs;
 using System.Text;
 using System.Runtime;
 using System.Runtime.InteropServices;
@@ -272,10 +273,23 @@ public unsafe void SIMDUtf8ValidationRealDataSse()
     }
     public class Program
     {
-        static void Main(string[] args) => BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args, DefaultConfig.Instance
-                .WithSummaryStyle(SummaryStyle.Default.WithMaxParameterColumnWidth(100)));
-
+        static void Main(string[] args)
+        {
+            if (args.Length == 0)
+            {
+                args = new string[] { "--filter", "*" };
+            }
+            var job = Job.Default
+                .WithWarmupCount(1)
+                .WithMinIterationCount(2)
+                .WithMaxIterationCount(10)
+                .AsDefault();
 
+            BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args, DefaultConfig.Instance.AddJob(job).WithSummaryStyle(SummaryStyle.Default.WithMaxParameterColumnWidth(100)));
+        }
     }
 
+
+    //  }
+
 }

benchmark/UTF8_runtime.cs

@@ -9,22 +9,8 @@
 using System.Runtime.Intrinsics.Arm;
 using System.Runtime.Intrinsics.X86;
 
-// Changes made from the Runtime (most of the stuff in the runtime is behind some private/internal class or some such. The path of least resistance was to copy paste.
-// Copy pasted from: https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,ca18aaa87cbdbfe8
-// https://source.dot.net/#System.Text.Encodings.Web/src/libraries/System.Private.CoreLib/src/System/Text/UnicodeUtility.cs,7d9353a7dd29c82b
-// https://source.dot.net/#System.Text.Encodings.Web/src/libraries/System.Private.CoreLib/src/System/Text/UnicodeDebug.cs,ac87f1ec2c614dce
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,0ca89dfb3ec2a5da
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,87a9969a4e35fdde
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,ff5eb1221e0665eb
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,068a221b81a99840
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,74fc59ef51d5afa8
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,7fc454ccbfa2fc31
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,70ca16f03c3cc41b
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,5a3126ae65f71ef2
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,6ee61246657067fb
-// https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Helpers.cs,706384069881fe22
-// 
-
+// Copy pasted from the System/Text/Unicode/Utf8Utility.Helpers.cs and associated files.
+// Important: copyright belongs to the .NET Foundation.
 namespace DotnetRuntime
 {
 

src/UTF8.cs

@@ -24,7 +24,7 @@ public static class UTF8
         public unsafe static byte* GetPointerToFirstInvalidByte(byte* pInputBuffer, int inputLength, out int Utf16CodeUnitCountAdjustment, out int ScalarCodeUnitCountAdjustment)
         {
 
-            if (AdvSimd.Arm64.IsSupported)
+            if (AdvSimd.Arm64.IsSupported && BitConverter.IsLittleEndian)
             {
                 return GetPointerToFirstInvalidByteArm64(pInputBuffer, inputLength, out Utf16CodeUnitCountAdjustment, out ScalarCodeUnitCountAdjustment);
             }
@@ -707,7 +707,6 @@ private unsafe static (int utfadjust, int scalaradjust) calculateErrorPathadjust
             return GetPointerToFirstInvalidByteScalar(pInputBuffer + processedLength, inputLength - processedLength, out utf16CodeUnitCountAdjustment, out scalarCountAdjustment);
         }
 
-//
         public unsafe static byte* GetPointerToFirstInvalidByteAvx2(byte* pInputBuffer, int inputLength, out int utf16CodeUnitCountAdjustment, out int scalarCountAdjustment)
         {
             int processedLength = 0;
@@ -851,7 +850,6 @@ private unsafe static (int utfadjust, int scalaradjust) calculateErrorPathadjust
                         {
                             // We have an ASCII block, no need to process it, but
                             // we need to check if the previous block was incomplete.
-                            // 
                             if (!Avx2.TestZ(prevIncomplete, prevIncomplete))
                             {
                                 int off = processedLength >= 3 ? processedLength - 3 : processedLength;