Add support printsysteminfo UCI command.

Add PEXT Bitboards

README.md

@@ -99,6 +99,8 @@ If you're a Linux user and are new to .NET ecosystem, the conversation in [this
 
 - Razoring [[1](https://www.chessprogramming.org/Razoring)]
 
+- PEXT Bitboards [[1](https://www.chessprogramming.org/BMI2#PEXTBitboards)]  [[2](https://analog-hors.github.io/site/magic-bitboards/)]
+
 ## Credits
 
 Lynx development wouldn't have been possible without:

src/Lynx.Benchmark/PEXT.cs

@@ -0,0 +1,44 @@
+using BenchmarkDotNet.Attributes;
+using Lynx.Model;
+
+namespace Lynx.Benchmark;
+public class PEXTBenchmark : BaseBenchmark
+{
+    private readonly Position _position = new Position(Constants.TrickyTestPositionFEN);
+
+    [Benchmark(Baseline = true)]
+    public ulong MagicNumbers()
+    {
+        ulong result = default;
+
+        for (int i = 0; i < 64; ++i)
+        {
+            result |= MagicNumbersRookAttacks(i, _position.OccupancyBitBoards[0]);
+            result |= MagicNumbersBishopAttacks(i, _position.OccupancyBitBoards[0]);
+        }
+
+        return result;
+    }
+
+    [Benchmark]
+    public ulong PEXT()
+    {
+        ulong result = default;
+
+        for (int i = 0; i < 64; ++i)
+        {
+            result |= PEXTRookAttacks(i, _position.OccupancyBitBoards[0]);
+            result |= PEXTBishopAttacks(i, _position.OccupancyBitBoards[0]);
+        }
+
+        return result;
+    }
+
+    private static BitBoard MagicNumbersRookAttacks(int squareIndex, BitBoard occupancy) => Attacks.MagicNumbersRookAttacks(squareIndex, occupancy);
+
+    private static BitBoard PEXTRookAttacks(int squareIndex, BitBoard occupancy) => Attacks.RookAttacks(squareIndex, occupancy);
+
+    private static BitBoard MagicNumbersBishopAttacks(int squareIndex, BitBoard occupancy) => Attacks.MagicNumbersBishopAttacks(squareIndex, occupancy);
+
+    private static BitBoard PEXTBishopAttacks(int squareIndex, BitBoard occupancy) => Attacks.BishopAttacks(squareIndex, occupancy);
+}

src/Lynx/LynxDriver.cs

@@ -2,6 +2,7 @@
 using Lynx.UCI.Commands.Engine;
 using Lynx.UCI.Commands.GUI;
 using NLog;
+using System.Runtime.Intrinsics.X86;
 using System.Text.Json;
 using System.Threading.Channels;
 
@@ -100,6 +101,9 @@ static ReadOnlySpan<char> ExtractCommandItems(string rawCommand)
                             case "printsettings":
                                 await HandleSettings();
                                 break;
+                            case "printsysteminfo":
+                                await HandleSystemInfo();
+                                break;
                             case "staticeval":
                                 await HandleStaticEval(rawCommand, cancellationToken);
                                 HandleQuit();
@@ -342,6 +346,22 @@ private async ValueTask HandleSettings()
         await _engineWriter.Writer.WriteAsync(message);
     }
 
+    private async ValueTask HandleSystemInfo()
+    {
+        try
+        {
+            var simd = Bmi2.X64.IsSupported
+                ? "Bmi2.X64 supported, PEXT BitBoards will be used"
+                : "Bmi2.X64 not supported";
+
+            await _engineWriter.Writer.WriteAsync(simd);
+        }
+        catch (Exception e)
+        {
+            _logger.Error(e);
+        }
+    }
+
     private async ValueTask HandleStaticEval(string rawCommand, CancellationToken cancellationToken)
     {
         try