Method calling

asm.md

public class Benchmark2
{
	private Base1 _b1;
	private Base2 _b2;

	[GlobalSetup]
	public void Setup()
	{
		_b1 = new Sub1();
		_b2 = new Sub2();
	}

	[Benchmark(Baseline = true)]
	public int M1()
	{
		int r = 0;
		for (int i = 0; i < 1000; i++)
		{
			r += _b1.Method(i);
		}
		return r;
	}

	[Benchmark]
	public int M2()
	{
		int r = 0;
		for (int i = 0; i < 1000; i++)
		{
			r += _b2.Method(i);
		}
		return r;
	}
}

public abstract class Base1
{
	public abstract int Method(int a);
}

public sealed class Sub1 : Base1
{
	private int _a;

	public override int Method(int a) => a - _a;
}

public abstract unsafe class Base2
{
	private readonly delegate*<Base2, int, int> _methodPtr;

	protected Base2(delegate*<Base2, int, int> methodPtr) => _methodPtr = methodPtr;

	public int Method(int a) => _methodPtr(this, a);
}
public sealed unsafe class Sub2 : Base2
{
	private int _a;

	public Sub2() : base(&Method) { }

	private static int Method(Base2 inst, int a) => a - Unsafe.As<Base2, Sub2>(ref inst)._a;
}

; Method CodingLab.ParseIt.Console.Benchmark2:M1():int:this (FullOpts)
G_M000_IG01:                ;; offset=0000H
       push     rdi
       push     rsi
       push     rbx
       sub      rsp, 32
       mov      rbx, rcx

G_M000_IG02:                ;; offset=000AH
       xor      esi, esi
       xor      edi, edi

G_M000_IG03:                ;; offset=000EH
       mov      rcx, gword ptr [rbx+08H]
       mov      edx, edi
       mov      rax, qword ptr [rcx]
       mov      rax, qword ptr [rax+40H]
       call     [rax+20H]CodingLab.ParseIt.Console.Base1:Method(int):int:this ; See Sub1::Method codegen below
       add      esi, eax
       inc      edi
       cmp      edi, 0x3E8
       jl       SHORT G_M000_IG03

G_M000_IG04:                ;; offset=002AH
       mov      eax, esi

G_M000_IG05:                ;; offset=002CH
       add      rsp, 32
       pop      rbx
       pop      rsi
       pop      rdi
       ret      
 ; END METHOD CodingLab.ParseIt.Console.Benchmark2:M1():int:this
; Total bytes of code: 52


; public sealed class Sub1 : Base1
; {
;   private int _a;
;
;	[MethodImpl(MethodImplOptions.AggressiveInlining)]
;	public override int Method(int a)
;	{
;		return a - _a;
      mov       eax,edx  
      sub       eax,dword ptr [rcx+8]  
      ret

; Method CodingLab.ParseIt.Console.Benchmark2:M2():int:this (FullOpts)
G_M000_IG01:                ;; offset=0000H
       push     rdi
       push     rsi
       push     rbx
       sub      rsp, 32
       mov      rbx, rcx

G_M000_IG02:                ;; offset=000AH
       xor      esi, esi
       xor      edi, edi

G_M000_IG03:                ;; offset=000EH
       mov      rcx, gword ptr [rbx+10H]
       mov      rax, qword ptr [rcx+08H]
       mov      edx, edi
       call     rax ; See Sub2::Method codegen below
       add      esi, eax
       inc      edi
       cmp      edi, 0x3E8
       jl       SHORT G_M000_IG03

G_M000_IG04:                ;; offset=0026H
       mov      eax, esi

G_M000_IG05:                ;; offset=0028H
       add      rsp, 32
       pop      rbx
       pop      rsi
       pop      rdi
       ret      
 ; END METHOD CodingLab.ParseIt.Console.Benchmark2:M2():int:this
; Total bytes of code: 48

; public sealed unsafe class Sub2 : Base2
; {
;	private int _a;
;
;	public Sub2() : base(&Method) {}
;
;	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
;	private static int Method(Base2 inst, int a)
;	{
;		return a - Unsafe.As<Base2, Sub2>(ref inst)._a;
      mov       eax,edx  
      sub       eax,dword ptr [rcx+10h]  
      ret

| Method |       Mean |  StdDev | Ratio | Code Size | Allocated | Alloc Ratio |
|------- |-----------:|--------:|------:|----------:|----------:|------------:|
|     M1 |   460.5 ns | 1.10 ns |  1.00 |      86 B |         - |          NA |
|     M2 | 1,605.9 ns | 3.81 ns |  3.49 |      48 B |         - |          NA |