Merge pull request #13 from simdutf/AVX2_UTF8_validation_disposable

Simplified version of AVX2 UTF-8 validation

Author: Nick-Nuon

README.md

@@ -3,29 +3,21 @@
 
 This is a fast C# library to process unicode strings.
 
-*It is currently not meant to be usable.*
 
 ## Motivation
 
-The most important immediate goal would be to speed up the 
-`Utf8Utility.GetPointerToFirstInvalidByte` function.
+We seek to speed up the `Utf8Utility.GetPointerToFirstInvalidByte` function. Using the algorithm used by Node.js, Oracle GraalVM  and other important systems.
 
-https://github.com/dotnet/runtime/blob/4d709cd12269fcbb3d0fccfb2515541944475954/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Validation.cs
-
-
-(We may need to speed up `Ascii.GetIndexOfFirstNonAsciiByte` first, see issue https://github.com/simdutf/SimdUnicode/issues/1.)
+- John Keiser, Daniel Lemire, [Validating UTF-8 In Less Than One Instruction Per Byte](https://arxiv.org/abs/2010.03090), Software: Practice and Experience 51 (5), 2021
 
-The question is whether we could do it using this routine:
+The function is private in the Runtime, but we can expose it manually.
 
-* John Keiser, Daniel Lemire, [Validating UTF-8 In Less Than One Instruction Per Byte](https://arxiv.org/abs/2010.03090), Software: Practice and Experience 51 (5), 2021
-
-Our generic implementation is available there: https://github.com/simdutf/simdutf/blob/master/src/generic/utf8_validation/utf8_lookup4_algorithm.h
+https://github.com/dotnet/runtime/blob/4d709cd12269fcbb3d0fccfb2515541944475954/src/libraries/System.Private.CoreLib/src/System/Text/Unicode/Utf8Utility.Validation.cs
 
-Porting it to C# is no joke, but doable.
 
 ## Requirements
 
-We recommend you install .NET 7: https://dotnet.microsoft.com/en-us/download/dotnet/7.0
+We recommend you install .NET 8: https://dotnet.microsoft.com/en-us/download/dotnet/8.0
 
 
 ## Running tests
@@ -35,8 +27,21 @@ cd test
 dotnet test
 ```
 
+To get a list of available tests, enter the command:
+
+```
+dotnet test --list-tests
+```
+
+To run specific tests, it is helpful to use the filter parameter:
+
+```
+dotnet test -c Release --filter Ascii
+```
+
 ## Running Benchmarks
 
+To run the benchmarks, run the following command:
 ```
 cd benchmark
 dotnet run -c Release
@@ -49,7 +54,6 @@ cd benchmark
 sudo dotnet run -c Release
 ```
 
-
 ## Building the library
 
 ```
@@ -66,10 +70,26 @@ cd test
 dotnet format
 ```
 
+## Programming tips
+
+You can print the content of a vector register like so:
+
+```C#
+        public static void ToString(Vector256<byte> v)
+        {
+            Span<byte> b = stackalloc byte[32];
+            v.CopyTo(b);
+            Console.WriteLine(Convert.ToHexString(b));
+        }
+```
 
 ## More reading 
 
 
 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/CS_runtime.cs renamed to benchmark/ASCII_runtime.cs

@@ -8,15 +8,18 @@
 using System.Runtime.Intrinsics.Arm;
 using System.Runtime.Intrinsics.X86;
 
+// This is from the Runtime. Copy/pasted as I found no other way to benchmark it.
+
 //Changes from original:
 //copy pasted CompExactlyDependsOnAttribute : Attribute into System.Text namespace
 //copy/pasted StoreLowerUnsafe into ascii class
 //The various Vector.Size likely refer to size in bytes so 
 //Replaced all instances of Vector512.Size by 64 (see:https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector512.cs,77df495766d5de9c)
 //Vector256's by 32 (see:https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector256.cs,877aa6254c4e4d00)
 //Vector128's by 16 (see:https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector128.cs,eb1e72a6f843c5a5)
+// GetIndexofFirstNonAsciiByte is no longer internal
 
-namespace Competition
+namespace DotnetRuntime
 {
     // I copy pasted this from: https://source.dot.net/#System.Private.CoreLib/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/CompExactlyDependsOnAttribute.cs
     // Use this attribute to indicate that a function should only be compiled into a Ready2Run
@@ -213,6 +216,7 @@ private static bool FirstCharInUInt32IsAscii(uint value)
         /// <returns>An ASCII byte is defined as 0x00 - 0x7F, inclusive.</returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal static unsafe nuint GetIndexOfFirstNonAsciiByte(byte* pBuffer, nuint bufferLength)
+        // internal static unsafe nuint GetIndexOfFirstNonAsciiByte(byte* pBuffer, nuint bufferLength)
         {
             // If 256/512-bit aren't supported but SSE2 is supported, use those specific intrinsics instead of
             // the generic vectorized code. This has two benefits: (a) we can take advantage of specific instructions