ps1 dotnet run -f net8.0 --runtimes net8.0 net481

BenchmarkDotNet v0.13.10, Windows 11 (10.0.22631.2715/23H2/2023Update/SunValley3) (Hyper-V) Intel Xeon Platinum 8370C CPU 2.80GHz, 1 CPU, 16 logical and 8 physical cores .NET SDK 8.0.100 [Host] : .NET 8.0.0 (8.0.23.53103), X64 RyuJIT AVX2 Job-DGVKHI : .NET 8.0.0 (8.0.23.53103), X64 RyuJIT AVX2 Job-QVBRTI : .NET Framework 4.8.1 (4.8.9181.0), X64 RyuJIT VectorSize=256

| Method | Runtime | Mean | Ratio | Code Size | |------- |--------------------- |----------:|------:|----------:| | Before | .NET 8.0 | 0.3349 ns | 1.00 | 38 B | | After | .NET 8.0 | 0.1841 ns | 0.55 | 36 B | | Before | .NET Framework 4.8.1 | 1.3028 ns | 3.88 | 114 B | | After | .NET Framework 4.8.1 | 0.4789 ns | 1.43 | 55 B |

.NET 8.0.0 (8.0.23.53103), X64 RyuJIT AVX2

assembly ; RoslynIssue56875.Benchmarks.Before(System.Nullable`1<System.DateTime>) ; public bool Before(DateTime? d) => d == DateTime.MaxValue; ; ^^^^^^^^^^^^^^^^^^^^^^ movzx eax,byte ptr [rdx] mov rcx,[rdx+8] test al,al je short M00_L00 mov rax,2BCA2875F4373FFF xor rax,rcx shl rax,2 sete al movzx eax,al ret M00_L00: xor eax,eax ret ; Total bytes of code 38

.NET 8.0.0 (8.0.23.53103), X64 RyuJIT AVX2

assembly ; RoslynIssue56875.Benchmarks.After(System.Nullable`1<System.DateTime>) ; public bool After(DateTime? d) => d.HasValue && d.GetValueOrDefault() == DateTime.MaxValue; ; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cmp byte ptr [rdx],0 je short M00_L00 mov rax,[rdx+8] mov rcx,2BCA2875F4373FFF xor rax,rcx shl rax,2 sete al movzx eax,al ret M00_L00: xor eax,eax ret ; Total bytes of code 36

.NET Framework 4.8.1 (4.8.9181.0), X64 RyuJIT VectorSize=256

assembly ; RoslynIssue56875.Benchmarks.Before(System.Nullable`1<System.DateTime>) sub rsp,18 vzeroupper xor eax,eax mov [rsp+8],rax mov [rsp+10],rax ; public bool Before(DateTime? d) => d == DateTime.MaxValue; ; ^^^^^^^^^^^^^^^^^^^^^^ vmovdqu xmm0,xmmword ptr [rdx] vmovdqu xmmword ptr [rsp+8],xmm0 mov rax,1BD1EDA1160 mov rax,[rax] mov rdx,[rax+8] cmp byte ptr [rsp+8],0 jne short M00_L00 xor eax,eax add rsp,18 ret M00_L00: cmp byte ptr [rsp+8],0 jne short M00_L01 mov eax,1 add rsp,18 ret M00_L01: mov rax,[rsp+10] mov rcx,3FFFFFFFFFFFFFFF and rax,rcx and rdx,rcx cmp rax,rdx sete al movzx eax,al add rsp,18 ret ; Total bytes of code 114

.NET Framework 4.8.1 (4.8.9181.0), X64 RyuJIT VectorSize=256

assembly ; RoslynIssue56875.Benchmarks.After(System.Nullable`1<System.DateTime>) cmp byte ptr [rdx],0 je short M00_L00 mov rax,[rdx+8] mov rdx,1C2E9031160 mov rdx,[rdx] mov rdx,[rdx+8] mov rcx,3FFFFFFFFFFFFFFF and rax,rcx and rdx,rcx cmp rax,rdx sete al movzx eax,al ret ; public bool After(DateTime? d) => d.HasValue && d.GetValueOrDefault() == DateTime.MaxValue; ; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ M00_L00: xor eax,eax ret ; Total bytes of code 55