Add mod benchmark

osu.Game.Benchmarks/BenchmarkMod.cs

@@ -0,0 +1,34 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using BenchmarkDotNet.Attributes;
+using osu.Game.Rulesets.Osu.Mods;
+
+namespace osu.Game.Benchmarks
+{
+    public class BenchmarkMod : BenchmarkTest
+    {
+        private OsuModDoubleTime mod;
+
+        [Params(1, 10, 100)]
+        public int Times { get; set; }
+
+        [GlobalSetup]
+        public void GlobalSetup()
+        {
+            mod = new OsuModDoubleTime();
+        }
+
+        [Benchmark]
+        public int ModHashCode()
+        {
+            var hashCode = new HashCode();
+
+            for (int i = 0; i < Times; i++)
+                hashCode.Add(mod);
+
+            return hashCode.ToHashCode();
+        }
+    }
+}