EgorBot for EgorBo in #109077

[EgorBot]

Processing https://github.com/dotnet/runtime/issues/109077#issuecomment-2427172652 command:

Command

-arm64 -amd --runtimes net8.0 net9.0 ```cs using System.Runtime.CompilerServices; using BenchmarkDotNet.Attributes; using BenchmarkDotNet.Running; using System.Collections.Generic; using System.Collections; public class MyClass {} public class Bench { object _obj = new MyClass[2]; [Benchmark] public int IsCollection() => _obj is ICollection coll ? coll.Count : 0; [Benchmark] public int IsCollection_expected() { var obj = _obj; if (obj is MyClass[]) return Unsafe.As(ref obj).Length; return 0; } } ```

(EgorBot will reply in this issue)

[EgorBot]

Benchmark results on Amd

BenchmarkDotNet v0.14.0, Ubuntu 24.04 LTS (Noble Numbat)
AMD EPYC 9R14, 1 CPU, 4 logical and 4 physical cores
  Job-HZMTFC : .NET 8.0.10 (8.0.1024.46610), X64 RyuJIT AVX-512F+CD+BW+DQ+VL+VBMI
  Job-TUJIVI : .NET 9.0.0 (9.0.24.47305), X64 RyuJIT AVX-512F+CD+BW+DQ+VL+VBMI

Method	Runtime	Mean	Error	Ratio
IsCollection	.NET 8.0	4.7780 ns	0.0190 ns	1.00
IsCollection	.NET 9.0	1.8073 ns	0.0189 ns	0.38
IsCollection_expected	.NET 8.0	1.3686 ns	0.0063 ns	1.00
IsCollection_expected	.NET 9.0	0.2773 ns	0.0035 ns	0.20

BDN_Artifacts.zip

[EgorBot]

cc @EgorBo (logs)

[EgorBot]

Benchmark results on Arm64

BenchmarkDotNet v0.14.0, Ubuntu 24.04 LTS (Noble Numbat)
Arm64
  Job-QVXRWJ : .NET 8.0.10 (8.0.1024.46610), Arm64 RyuJIT AdvSIMD
  Job-GAOKJD : .NET 9.0.0 (9.0.24.47305), Arm64 RyuJIT AdvSIMD

Method	Runtime	Mean	Error	Ratio
IsCollection	.NET 8.0	7.6679 ns	0.0022 ns	1.00
IsCollection	.NET 9.0	1.1448 ns	0.0001 ns	0.15
IsCollection_expected	.NET 8.0	0.0814 ns	0.0002 ns	1.000
IsCollection_expected	.NET 9.0	0.0000 ns	0.0000 ns	0.000

BDN_Artifacts.zip

[EgorBot]

cc @EgorBo (logs)