stringisnullorempty.asm

## .NET 6.0.10 (6.0.1022.47605), X64 RyuJIT AVX2
```assembly
; Program.StringIsLengthDynamic()
       push      rdi
       push      rsi
       sub       rsp,28
;         var result = 0;
;         ^^^^^^^^^^^^^^^
       xor       esi,esi
;         for (var n = 0; n < 10000; n++)
;              ^^^^^^^^^
       xor       edi,edi
       mov       rcx,7FFA50774F30
       mov       edx,4
       call      CORINFO_HELP_GETSHARED_NONGCSTATIC_BASE
       mov       rax,238B4367340
       mov       rax,[rax]
;             if (empty is { Length: 0 }) { result++; }
;             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
M00_L00:
       mov       rdx,rax
       test      rdx,rdx
       je        short M00_L01
       cmp       dword ptr [rdx+8],0
       jne       short M00_L01
       inc       esi
;             if (nonEmpty is { Length: 0 }) { result++; }
;             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
M00_L01:
       mov       rdx,238B4367348
       mov       rdx,[rdx]
       test      rdx,rdx
       je        short M00_L02
       cmp       dword ptr [rdx+8],0
       jne       short M00_L02
       inc       esi
M00_L02:
       inc       edi
       cmp       edi,2710
       jl        short M00_L00
;         return result;
;         ^^^^^^^^^^^^^^
       mov       eax,esi
       add       rsp,28
       pop       rsi
       pop       rdi
       ret
; Total bytes of code 104
```

## .NET 6.0.10 (6.0.1022.47605), X64 RyuJIT AVX2
```assembly
; Program.StringIsNullOrEmptyDynamic()
       push      rdi
       push      rsi
       sub       rsp,28
;         var result = 0;
;         ^^^^^^^^^^^^^^^
       xor       esi,esi
;         for (var n = 0; n < 10000; n++)
;              ^^^^^^^^^
       xor       edi,edi
       mov       rcx,7FFA50784F30
       mov       edx,4
       call      CORINFO_HELP_GETSHARED_NONGCSTATIC_BASE
       mov       rax,2164DDA7340
       mov       rax,[rax]
;             if (string.IsNullOrEmpty(empty)) { result++; }
;             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
M00_L00:
       mov       rdx,rax
       test      rdx,rdx
       je        short M00_L01
       cmp       dword ptr [rdx+8],0
       jne       short M00_L02
M00_L01:
       inc       esi
;             if (string.IsNullOrEmpty(nonEmpty)) { result++; }
;             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
M00_L02:
       mov       rdx,2164DDA7348
       mov       rdx,[rdx]
       test      rdx,rdx
       je        short M00_L03
       cmp       dword ptr [rdx+8],0
       jne       short M00_L04
M00_L03:
       inc       esi
M00_L04:
       inc       edi
       cmp       edi,2710
       jl        short M00_L00
;         return result;
;         ^^^^^^^^^^^^^^
       mov       eax,esi
       add       rsp,28
       pop       rsi
       pop       rdi
       ret
; Total bytes of code 104
```

## .NET 6.0.10 (6.0.1022.47605), X64 RyuJIT AVX2
```assembly
; Program.StringIsLength()
;         var result = 0;
;         ^^^^^^^^^^^^^^^
       xor       eax,eax
;         for (var n = 0; n < 10000; n++)
;              ^^^^^^^^^
       xor       edx,edx
       mov       rcx,1F698003020
       mov       rcx,[rcx]
       mov       r8,1F69800A110
       mov       r8,[r8]
;             var x = "";
;             ^^^^^^^^^^^
M00_L00:
       mov       r9,rcx
;             if (x is { Length: 0 }) { result++; }
;             ^^^^^^^^^^^^^^^^^^^^^^^
       cmp       dword ptr [r9+8],0
       jne       short M00_L01
       inc       eax
;             x = "a";
;             ^^^^^^^^
M00_L01:
       mov       r9,r8
;             if (x is { Length: 0 }) { result++; }
;             ^^^^^^^^^^^^^^^^^^^^^^^
       cmp       dword ptr [r9+8],0
       jne       short M00_L02
       inc       eax
M00_L02:
       inc       edx
       cmp       edx,2710
       jl        short M00_L00
       ret
; Total bytes of code 65
```

## .NET 6.0.10 (6.0.1022.47605), X64 RyuJIT AVX2
```assembly
; Program.StringIsNullOrEmpty()
;         var result = 0;
;         ^^^^^^^^^^^^^^^
       xor       eax,eax
;         for (var n = 0; n < 10000; n++)
;              ^^^^^^^^^
       xor       edx,edx
;                 result++;
;                 ^^^^^^^^^
M00_L00:
       inc       eax
       inc       edx
       cmp       edx,2710
       jl        short M00_L00
       ret
; Total bytes of code 17
```



using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

[DisassemblyDiagnoser(printSource: true, exportDiff:true)]
[RyuJitX64Job]
public class Program
{
    public static string empty = "";
    public static string nonEmpty = "a";
    
    [Benchmark()]
    public int StringIsLengthDynamic()
    {
        var result = 0;
        for (var n = 0; n < 10000; n++)
        {
            if (empty is { Length: 0 }) { result++; }
            if (nonEmpty is { Length: 0 }) { result++; }
        }

        return result;
    }
    
    [Benchmark()]
    public int StringIsNullOrEmptyDynamic()
    {
        var result = 0;
        for (var n = 0; n < 10000; n++)
        {
            if (string.IsNullOrEmpty(empty)) { result++; }
            if (string.IsNullOrEmpty(nonEmpty)) { result++; }
        }

        return result;
    }
    
    [Benchmark()]
    public int StringIsLength()
    {
        var result = 0;
        for (var n = 0; n < 10000; n++)
        {
            var x = "";
            if (x is { Length: 0 }) { result++; }

            x = "a";
            if (x is { Length: 0 }) { result++; }
        }

        return result;
    }
    
    [Benchmark()]
    public int StringIsNullOrEmpty()
    {
        var result = 0;

        for (var n = 0; n < 10000; n++)
        {
            var x = "";

            if (string.IsNullOrEmpty(x))
            {
                result++;
            }

            x = "a";
            
            if (string.IsNullOrEmpty(x))
            {
                result++;
            }
        }

        return result;
    }
    
    public static void Main()
    {
        empty = "";
        nonEmpty = "a";
        BenchmarkRunner.Run(typeof(Program).Assembly);
    }
}