[Perf][Mono] Speed regression in Buffer.BlockCopy across all Mono AOT and WASM configurations on 3/24/2025 4:04:18 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [28c417f605ba0f04af980847695ec9de470743a0](https://github.com/dotnet/runtime/commit/28c417f605ba0f04af980847695ec9de470743a0)
Compare | [659321ff5db13026f52aec70cf2a6692bd4be454](https://github.com/dotnet/runtime/commit/659321ff5db13026f52aec70cf2a6692bd4be454)
Diff | [Diff](https://github.com/dotnet/runtime/compare/28c417f605ba0f04af980847695ec9de470743a0...659321ff5db13026f52aec70cf2a6692bd4be454)
Configs | CompilationMode:tiered, LLVM:true, MonoAOT:true, MonoInterpreter:false, RunKind:micro_mono


### Regressions in System.Memory.ReadOnlySpan

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|<ul><li>[IndexOfString - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.ReadOnlySpan.IndexOfString(input%3a%20%22AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/ReadOnlySpan.cs#L45-#L65>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 162.58 ns | 178.38 ns | 1.10 | 0.10 | False | | |
|<ul><li>[IndexOfString - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.ReadOnlySpan.IndexOfString(input%3a%20%22Hello%20WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello%20WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello%20Worldbbbbbbbbbbbbbbbbbb.html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/ReadOnlySpan.cs#L45-#L65>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 68.50 ns | 73.45 ns | 1.07 | 0.10 | False | | |
|<ul><li>[IndexOfString - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.ReadOnlySpan.IndexOfString(input%3a%20%22%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0%e3%81%a0.html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/ReadOnlySpan.cs#L45-#L65>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 162.42 ns | 178.17 ns | 1.10 | 0.11 | False | | |
|<ul><li>[IndexOfString - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.ReadOnlySpan.IndexOfString(input%3a%20%22Hello%20WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello%20WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello%20Worldbbbbbbbbbbbbbbbbbbb.html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/ReadOnlySpan.cs#L45-#L65>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 22.65 ns | 28.10 ns | 1.24 | 0.07 | False | | |

![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.ReadOnlySpan_001.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.ReadOnlySpan_002.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.ReadOnlySpan_003.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.ReadOnlySpan_004.png>)
[Test Report](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.ReadOnlySpan.html>)

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

<details>
<summary>Repro Steps</summary>


#### Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))
- Libraries build extracted to `runtime/artifacts` or build instructions: [Libraries README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/libraries/README.md) args: `-subset libs+libs.tests -rc release -configuration Release -arch $RunArch -framework net8.0`
- CoreCLR product build extracted to `runtime/artifacts/bin/coreclr/$RunOS.$RunArch.Release`, build instructions: [CoreCLR README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/coreclr/README.md) args: `-subset clr+libs -rc release -configuration Release -arch $RunArch -framework net8.0`
- AOT MONO build extracted to `runtime/artifacts/bin/mono/$RunOS.$RunArch.Release`, build instructions: [MONO README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/mono/README.md) args: `-arch $RunArch -os $RunOS -s mono+libs+host+packs -c Release /p:CrossBuild=false /p:MonoLLVMUseCxx11Abi=false`
- Dotnet SDK installed for dotnet commands
- Running commands from the runtime folder

Linux
```cmd
# Set $RunDir to the runtime directory
RunDir=`pwd`

# Set the OS, arch, and OSId
RunOS='linux'
RunOSId='linux'
RunArch='x64'

# Create aot directory
mkdir -p $RunDir/artifacts/bin/aot/sgen
mkdir -p $RunDir/artifacts/bin/aot/pack
cp -r $RunDir/artifacts/obj/mono/$RunOS.$RunArch.Release/mono/* $RunDir/artifacts/bin/aot/sgen
cp -r $RunDir/artifacts/bin/microsoft.netcore.app.runtime.$RunOS-$RunArch/Release/* $RunDir/artifacts/bin/aot/pack

# Create Core Root
$RunDir/src/tests/build.sh release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir/performance

# One line run:
python3 $RunDir/performance/scripts/benchmarks_ci.py --csproj $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'System.Memory.ReadOnlySpan*' --bdn-artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --packages $RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter System.Memory.ReadOnlySpan* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --packages $RunDir/performance/artifacts/packages --buildTimeout 1200
```

Windows
```cmd
# Set $RunDir to the runtime directory
$RunDir="FullPathHere"

# Set the OS, arch, and OSId
RunOS='windows'
RunOSId='win'
RunArch='x64'

# Create aot directory
mkdir $RunDir\artifacts\bin\aot\sgen
mkdir $RunDir\artifacts\bin\aot\pack
xcopy $RunDir\artifacts\obj\mono\$RunOS.$RunArch.Release\mono $RunDir\artifacts\bin\aot\sgen\ /e /y
xcopy $RunDir\artifacts\bin\microsoft.netcore.app.runtime.$RunOSId-$RunArch\Release $RunDir\artifacts\bin\aot\pack\ /e /y

# Create Core Root
$RunDir\src\tests\build.cmd release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir\performance

# One line run:
python3 $RunDir\performance\scripts\benchmarks_ci.py --csproj $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'System.Memory.ReadOnlySpan*' --bdn-artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --packages $RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter System.Memory.ReadOnlySpan* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack -aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --packages $RunDir\performance\artifacts\packages --buildTimeout 1200
```

</details>

<details>

### System.Memory.ReadOnlySpan.IndexOfString(input: "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAXAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", value: "X", comparisonType: Ordinal)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.ReadOnlySpan.IndexOfString(input: "Hello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello Worldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylong!xyz", value: "~", comparisonType: Ordinal)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.ReadOnlySpan.IndexOfString(input: "だだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだxだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだだ", value: "x", comparisonType: Ordinal)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.ReadOnlySpan.IndexOfString(input: "Hello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello Worldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylong!xyz", value: "w", comparisonType: OrdinalIgnoreCase)

#### ETL Files

#### Histogram

#### JIT Disasms



### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

</details>


---


### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [365dde344601cc5310493133cfc1ee7588be1c6f](https://github.com/dotnet/runtime/commit/365dde344601cc5310493133cfc1ee7588be1c6f)
Compare | [659321ff5db13026f52aec70cf2a6692bd4be454](https://github.com/dotnet/runtime/commit/659321ff5db13026f52aec70cf2a6692bd4be454)
Diff | [Diff](https://github.com/dotnet/runtime/compare/365dde344601cc5310493133cfc1ee7588be1c6f...659321ff5db13026f52aec70cf2a6692bd4be454)
Configs | CompilationMode:tiered, LLVM:true, MonoAOT:true, MonoInterpreter:false, RunKind:micro_mono


### Regressions in System.Memory.Span&lt;Int32&gt;

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|<ul><li>[IndexOfAnyFiveValues - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.Span(Int32).IndexOfAnyFiveValues(Size%3a%20512).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/Span.cs#L90-#L91>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 2.33 μs | 2.85 μs | 1.22 | 0.04 | False | | |
|<ul><li>[IndexOfValue - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.Span(Int32).IndexOfValue(Size%3a%20512).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/Span.cs#L78-#L79>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=H4sIAAAAAAAACl1S32/TMBB+r9T/4eiLW5E1WUo1CBgxtgkmVk1aqvGITHJpjRw7Ol9YC+N/x07bl73cyffju/u+s0EGRs8g4ZMo956xna+wdbSfl52yH24tL/KP81tb4+6+eVSmx2mp/2ABy/N8Jt6PRyYgqIaRAkStGFm3OM2zfHmW5WfZ+Tp7V+Rvi8VivlxcvMkuFq+zrMiy2bGTsHOhUdSOLXJKvY39J9yfpGy1jXnCxqdbVLVPW6XtqaByttGbOHlvVaur6V9x5dpOG8Xa2ZWrURQgWCNhLRIQd3ePqyFCPcb3yll3eb9+GQqskTrCYGOqUcYPuYfeftO2jrEwjNyPNhSLf5HMF+Sv2rMjXSlzrVh917yNuyjS3lk/jSrLaJKDXHKwyaCAjCY50pUHlxzJyYObjUfP0JH7hRVDiaTRJ/C516ZeB8FKVm2XwHAfuQ5DrlxQEukBfW/48jeS2uB4lKbP8LQNYhwR4FUA56Cnh8mE3c2uMn2NkwmkKdzsAqRBcA002gQsbTfg+nBs8ENzXIgwfAyCeLNqq4jhKbCG6aFAntbcVc70rZUv190f4l4Oe4c61mxQiiBflHt/fK5Q+Z6wRcti9h/Vy44BsQIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=>)</li></ul> | 159.71 ns | 188.72 ns | 1.18 | 0.12 | False | | |
|<ul><li>[IndexOfAnyFourValues - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.Span(Int32).IndexOfAnyFourValues(Size%3a%20512).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/Span.cs#L87-#L88>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 1.94 μs | 2.43 μs | 1.25 | 0.04 | False | | |
|<ul><li>[IndexOfAnyFourValues - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.Span(Int32).IndexOfAnyFourValues(Size%3a%2033).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/Span.cs#L87-#L88>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=H4sIAAAAAAAACl1S32/TMBB+r9T/4ehLWpE1Id3QWjCibAMmVk1aq/GITHJpjRw7Op9ZA+N/x07bl73cyffju/u+s0YGRscg4GOy7hxjM11hY6mbrltp3t8anhUfpremwv19vTTdZ+vpUWqPbrxWf3ABs9kkeTcc6AAka0YKSJVkZNXguMiLi7O8OMvfbPL5orhcXMymb+fn+eX8/HWeL/J8cuwkbG1oTCrLBjkjb2L/CfcnSVPuYp6wdtkOZeWyRipzKiitqdU2Tu6MbFQ5/ptc2aZVWrKyZmUrTBaQsELCKkkhubt7XPUR8hjfK2vs8n7zMhTII7WEwcZULbXrcw/efFOmirEwjOyPJhQn/yKZL8hflWNLqpT6WrL8rngXd5GknDVuHMUW0aQHuURv014BEU16pCsOLj2SEwc3GQ6eoSX7C0uGNZJCl8Inr3S1CYKtWTZtCv19xCYMubJBSaQHdF7z8jeS3OJwkGXP8LQLYhwR4FUA56Cng9GI7c2+1L7C0QiyDG72AVIj2BpqpQOWMluwPhwbXN8cFyIM/4Mg3qzcSWJ4CqxhfCgQpzX3pdW+MeLlut0h7kS/d6hjxRpFEuSLcnfH5wql84QNGk4m/wFsmnq5uAIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=>)</li></ul> | 142.23 ns | 171.40 ns | 1.21 | 0.04 | False | | |
|<ul><li>[SequenceCompareTo - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.Span(Int32).SequenceCompareTo(Size%3a%2033).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/Span.cs#L55-#L56>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 117.62 ns | 143.00 ns | 1.22 | 0.25 | False | | |
|<ul><li>[IndexOfAnyFiveValues - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.Memory.Span(Int32).IndexOfAnyFiveValues(Size%3a%2033).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Memory/Span.cs#L90-#L91>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 168.18 ns | 197.04 ns | 1.17 | 0.05 | False | | |

![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.Span%28Int32%29_001.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.Span%28Int32%29_002.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.Span%28Int32%29_003.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.Span%28Int32%29_004.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.Span%28Int32%29_005.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.Span%28Int32%29_006.png>)
[Test Report](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.Memory.Span%28Int32%29.html>)

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

<details>
<summary>Repro Steps</summary>


#### Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))
- Libraries build extracted to `runtime/artifacts` or build instructions: [Libraries README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/libraries/README.md) args: `-subset libs+libs.tests -rc release -configuration Release -arch $RunArch -framework net8.0`
- CoreCLR product build extracted to `runtime/artifacts/bin/coreclr/$RunOS.$RunArch.Release`, build instructions: [CoreCLR README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/coreclr/README.md) args: `-subset clr+libs -rc release -configuration Release -arch $RunArch -framework net8.0`
- AOT MONO build extracted to `runtime/artifacts/bin/mono/$RunOS.$RunArch.Release`, build instructions: [MONO README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/mono/README.md) args: `-arch $RunArch -os $RunOS -s mono+libs+host+packs -c Release /p:CrossBuild=false /p:MonoLLVMUseCxx11Abi=false`
- Dotnet SDK installed for dotnet commands
- Running commands from the runtime folder

Linux
```cmd
# Set $RunDir to the runtime directory
RunDir=`pwd`

# Set the OS, arch, and OSId
RunOS='linux'
RunOSId='linux'
RunArch='x64'

# Create aot directory
mkdir -p $RunDir/artifacts/bin/aot/sgen
mkdir -p $RunDir/artifacts/bin/aot/pack
cp -r $RunDir/artifacts/obj/mono/$RunOS.$RunArch.Release/mono/* $RunDir/artifacts/bin/aot/sgen
cp -r $RunDir/artifacts/bin/microsoft.netcore.app.runtime.$RunOS-$RunArch/Release/* $RunDir/artifacts/bin/aot/pack

# Create Core Root
$RunDir/src/tests/build.sh release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir/performance

# One line run:
python3 $RunDir/performance/scripts/benchmarks_ci.py --csproj $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'System.Memory.Span&lt;Int32&gt;*' --bdn-artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --packages $RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter System.Memory.Span&lt;Int32&gt;* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --packages $RunDir/performance/artifacts/packages --buildTimeout 1200
```

Windows
```cmd
# Set $RunDir to the runtime directory
$RunDir="FullPathHere"

# Set the OS, arch, and OSId
RunOS='windows'
RunOSId='win'
RunArch='x64'

# Create aot directory
mkdir $RunDir\artifacts\bin\aot\sgen
mkdir $RunDir\artifacts\bin\aot\pack
xcopy $RunDir\artifacts\obj\mono\$RunOS.$RunArch.Release\mono $RunDir\artifacts\bin\aot\sgen\ /e /y
xcopy $RunDir\artifacts\bin\microsoft.netcore.app.runtime.$RunOSId-$RunArch\Release $RunDir\artifacts\bin\aot\pack\ /e /y

# Create Core Root
$RunDir\src\tests\build.cmd release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir\performance

# One line run:
python3 $RunDir\performance\scripts\benchmarks_ci.py --csproj $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'System.Memory.Span&lt;Int32&gt;*' --bdn-artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --packages $RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter System.Memory.Span&lt;Int32&gt;* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack -aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --packages $RunDir\performance\artifacts\packages --buildTimeout 1200
```

</details>

<details>

### System.Memory.Span&lt;Int32&gt;.IndexOfAnyFiveValues(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span&lt;Int32&gt;.IndexOfValue(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span&lt;Int32&gt;.IndexOfAnyFourValues(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span&lt;Int32&gt;.IndexOfAnyFourValues(Size: 33)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span&lt;Int32&gt;.SequenceCompareTo(Size: 33)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span&lt;Int32&gt;.IndexOfAnyFiveValues(Size: 33)

#### ETL Files

#### Histogram

#### JIT Disasms



### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

</details>


---


### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [28c417f605ba0f04af980847695ec9de470743a0](https://github.com/dotnet/runtime/commit/28c417f605ba0f04af980847695ec9de470743a0)
Compare | [659321ff5db13026f52aec70cf2a6692bd4be454](https://github.com/dotnet/runtime/commit/659321ff5db13026f52aec70cf2a6692bd4be454)
Diff | [Diff](https://github.com/dotnet/runtime/compare/28c417f605ba0f04af980847695ec9de470743a0...659321ff5db13026f52aec70cf2a6692bd4be454)
Configs | CompilationMode:tiered, LLVM:true, MonoAOT:true, MonoInterpreter:false, RunKind:micro_mono


### Regressions in PerfLabTests.BlockCopyPerf

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|<ul><li>[CallBlockCopy - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements%3a%20100).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/runtime/perflab/BlockCopyPerf.cs#L21-#L23>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 23.00 ns | 34.38 ns | 1.50 | 0.27 | False | | |
|<ul><li>[CallBlockCopy - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements%3a%2010).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/runtime/perflab/BlockCopyPerf.cs#L21-#L23>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 24.05 ns | 31.72 ns | 1.32 | 0.50 | False | | |
|<ul><li>[CallBlockCopy - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements%3a%201000).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/runtime/perflab/BlockCopyPerf.cs#L21-#L23>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 41.23 ns | 104.42 ns | 2.53 | 0.21 | False | | |

![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/PerfLabTests.BlockCopyPerf_001.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/PerfLabTests.BlockCopyPerf_002.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/PerfLabTests.BlockCopyPerf_003.png>)
[Test Report](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/PerfLabTests.BlockCopyPerf.html>)

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

<details>
<summary>Repro Steps</summary>


#### Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))
- Libraries build extracted to `runtime/artifacts` or build instructions: [Libraries README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/libraries/README.md) args: `-subset libs+libs.tests -rc release -configuration Release -arch $RunArch -framework net8.0`
- CoreCLR product build extracted to `runtime/artifacts/bin/coreclr/$RunOS.$RunArch.Release`, build instructions: [CoreCLR README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/coreclr/README.md) args: `-subset clr+libs -rc release -configuration Release -arch $RunArch -framework net8.0`
- AOT MONO build extracted to `runtime/artifacts/bin/mono/$RunOS.$RunArch.Release`, build instructions: [MONO README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/mono/README.md) args: `-arch $RunArch -os $RunOS -s mono+libs+host+packs -c Release /p:CrossBuild=false /p:MonoLLVMUseCxx11Abi=false`
- Dotnet SDK installed for dotnet commands
- Running commands from the runtime folder

Linux
```cmd
# Set $RunDir to the runtime directory
RunDir=`pwd`

# Set the OS, arch, and OSId
RunOS='linux'
RunOSId='linux'
RunArch='x64'

# Create aot directory
mkdir -p $RunDir/artifacts/bin/aot/sgen
mkdir -p $RunDir/artifacts/bin/aot/pack
cp -r $RunDir/artifacts/obj/mono/$RunOS.$RunArch.Release/mono/* $RunDir/artifacts/bin/aot/sgen
cp -r $RunDir/artifacts/bin/microsoft.netcore.app.runtime.$RunOS-$RunArch/Release/* $RunDir/artifacts/bin/aot/pack

# Create Core Root
$RunDir/src/tests/build.sh release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir/performance

# One line run:
python3 $RunDir/performance/scripts/benchmarks_ci.py --csproj $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'PerfLabTests.BlockCopyPerf*' --bdn-artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --packages $RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter PerfLabTests.BlockCopyPerf* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --packages $RunDir/performance/artifacts/packages --buildTimeout 1200
```

Windows
```cmd
# Set $RunDir to the runtime directory
$RunDir="FullPathHere"

# Set the OS, arch, and OSId
RunOS='windows'
RunOSId='win'
RunArch='x64'

# Create aot directory
mkdir $RunDir\artifacts\bin\aot\sgen
mkdir $RunDir\artifacts\bin\aot\pack
xcopy $RunDir\artifacts\obj\mono\$RunOS.$RunArch.Release\mono $RunDir\artifacts\bin\aot\sgen\ /e /y
xcopy $RunDir\artifacts\bin\microsoft.netcore.app.runtime.$RunOSId-$RunArch\Release $RunDir\artifacts\bin\aot\pack\ /e /y

# Create Core Root
$RunDir\src\tests\build.cmd release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir\performance

# One line run:
python3 $RunDir\performance\scripts\benchmarks_ci.py --csproj $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'PerfLabTests.BlockCopyPerf*' --bdn-artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --packages $RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter PerfLabTests.BlockCopyPerf* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack -aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --packages $RunDir\performance\artifacts\packages --buildTimeout 1200
```

</details>

<details>

### PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements: 100)

#### ETL Files

#### Histogram

#### JIT Disasms

### PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements: 10)

#### ETL Files

#### Histogram

#### JIT Disasms

### PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements: 1000)

#### ETL Files

#### Histogram

#### JIT Disasms



### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

</details>


---


### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [365dde344601cc5310493133cfc1ee7588be1c6f](https://github.com/dotnet/runtime/commit/365dde344601cc5310493133cfc1ee7588be1c6f)
Compare | [659321ff5db13026f52aec70cf2a6692bd4be454](https://github.com/dotnet/runtime/commit/659321ff5db13026f52aec70cf2a6692bd4be454)
Diff | [Diff](https://github.com/dotnet/runtime/compare/365dde344601cc5310493133cfc1ee7588be1c6f...659321ff5db13026f52aec70cf2a6692bd4be454)
Configs | CompilationMode:tiered, LLVM:true, MonoAOT:true, MonoInterpreter:false, RunKind:micro_mono


### Regressions in System.IO.Tests.Perf_StreamWriter

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|<ul><li>[WriteString - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.IO.Tests.Perf_StreamWriter.WriteString(writeLength%3a%20100).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Runtime.Extensions/Perf.StreamWriter.cs#L96-#L117>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 648.56 ms | 770.55 ms | 1.19 | 0.03 | False | | |
|<ul><li>[WriteCharArray - Duration of single invocation](<https://pvscmdupload.z22.web.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_ubuntu 22.04_LLVM=true_MonoAOT=true_MonoInterpreter=false_RunKind=micro_mono/System.IO.Tests.Perf_StreamWriter.WriteCharArray(writeLength%3a%20100).html>)</li><li>📝 - [Benchmark Source](<https://github.com/dotnet/performance/blob/main/src/benchmarks/micro/libraries/System.Runtime.Extensions/Perf.StreamWriter.cs#L49-#L70>)</li><li>[ADX - Test Multi Config Graph](<https://dataexplorer.azure.com/clusters/dotnetperf.westus/databases/PerformanceData?query=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>)</li></ul> | 637.80 ms | 914.55 ms | 1.43 | 0.03 | False | | |

![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.IO.Tests.Perf_StreamWriter_001.png>)
![graph](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.IO.Tests.Perf_StreamWriter_002.png>)
[Test Report](<https://pvscmdupload.z22.web.core.windows.net/autofilereport/autofilereports/04_01_2025/refs/heads/main_arm64_ubuntu%2022.04_LLVM%3Dtrue_MonoAOT%3Dtrue_MonoInterpreter%3Dfalse_RunKind%3Dmicro_mono_Regression/System.IO.Tests.Perf_StreamWriter.html>)

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

<details>
<summary>Repro Steps</summary>


#### Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))
- Libraries build extracted to `runtime/artifacts` or build instructions: [Libraries README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/libraries/README.md) args: `-subset libs+libs.tests -rc release -configuration Release -arch $RunArch -framework net8.0`
- CoreCLR product build extracted to `runtime/artifacts/bin/coreclr/$RunOS.$RunArch.Release`, build instructions: [CoreCLR README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/coreclr/README.md) args: `-subset clr+libs -rc release -configuration Release -arch $RunArch -framework net8.0`
- AOT MONO build extracted to `runtime/artifacts/bin/mono/$RunOS.$RunArch.Release`, build instructions: [MONO README](https://github.com/dotnet/runtime/blob/main/docs/workflow/building/mono/README.md) args: `-arch $RunArch -os $RunOS -s mono+libs+host+packs -c Release /p:CrossBuild=false /p:MonoLLVMUseCxx11Abi=false`
- Dotnet SDK installed for dotnet commands
- Running commands from the runtime folder

Linux
```cmd
# Set $RunDir to the runtime directory
RunDir=`pwd`

# Set the OS, arch, and OSId
RunOS='linux'
RunOSId='linux'
RunArch='x64'

# Create aot directory
mkdir -p $RunDir/artifacts/bin/aot/sgen
mkdir -p $RunDir/artifacts/bin/aot/pack
cp -r $RunDir/artifacts/obj/mono/$RunOS.$RunArch.Release/mono/* $RunDir/artifacts/bin/aot/sgen
cp -r $RunDir/artifacts/bin/microsoft.netcore.app.runtime.$RunOS-$RunArch/Release/* $RunDir/artifacts/bin/aot/pack

# Create Core Root
$RunDir/src/tests/build.sh release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir/performance

# One line run:
python3 $RunDir/performance/scripts/benchmarks_ci.py --csproj $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'System.IO.Tests.Perf_StreamWriter*' --bdn-artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --packages $RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir/performance/artifacts/packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir/performance/src/benchmarks/micro/MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter System.IO.Tests.Perf_StreamWriter* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir/artifacts/bin/aot/sgen/mini/mono-sgen --customruntimepack $RunDir/artifacts/bin/aot/pack --aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir/artifacts/BenchmarkDotNet.Artifacts --packages $RunDir/performance/artifacts/packages --buildTimeout 1200
```

Windows
```cmd
# Set $RunDir to the runtime directory
$RunDir="FullPathHere"

# Set the OS, arch, and OSId
RunOS='windows'
RunOSId='win'
RunArch='x64'

# Create aot directory
mkdir $RunDir\artifacts\bin\aot\sgen
mkdir $RunDir\artifacts\bin\aot\pack
xcopy $RunDir\artifacts\obj\mono\$RunOS.$RunArch.Release\mono $RunDir\artifacts\bin\aot\sgen\ /e /y
xcopy $RunDir\artifacts\bin\microsoft.netcore.app.runtime.$RunOSId-$RunArch\Release $RunDir\artifacts\bin\aot\pack\ /e /y

# Create Core Root
$RunDir\src\tests\build.cmd release $RunArch generatelayoutonly /p:LibrariesConfiguration=Release

# Clone performance
git clone --branch main --depth 1 --quiet https://github.com/dotnet/performance.git $RunDir\performance

# One line run:
python3 $RunDir\performance\scripts\benchmarks_ci.py --csproj $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --incremental no --architecture $RunArch -f net8.0 --filter 'System.IO.Tests.Perf_StreamWriter*' --bdn-artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --bdn-arguments="--anyCategories Libraries Runtime  --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack --aotcompilermode llvm --logBuildOutput --generateBinLog"

# Individual Commands:
# Restore
dotnet restore $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --packages $RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Build
dotnet build $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore /p:NuGetPackageRoot=$RunDir\performance\artifacts\packages /p:UseSharedCompilation=false /p:BuildInParallel=false /m:1

# Run
dotnet run --project $RunDir\performance\src\benchmarks\micro\MicroBenchmarks.csproj --configuration Release --framework net8.0 --no-restore --no-build -- --filter System.IO.Tests.Perf_StreamWriter* --anyCategories Libraries Runtime " --category-exclusion-filter NoAOT NoWASM --runtimes monoaotllvm --aotcompilerpath $RunDir\artifacts\bin\aot\sgen\mini\mono-sgen.exe --customruntimepack $RunDir\artifacts\bin\aot\pack -aotcompilermode llvm --logBuildOutput --generateBinLog " --artifacts $RunDir\artifacts\BenchmarkDotNet.Artifacts --packages $RunDir\performance\artifacts\packages --buildTimeout 1200
```

</details>

<details>

### System.IO.Tests.Perf_StreamWriter.WriteString(writeLength: 100)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.IO.Tests.Perf_StreamWriter.WriteCharArray(writeLength: 100)

#### ETL Files

#### Histogram

#### JIT Disasms



### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

</details>

Name	Value
Architecture	arm64
OS	ubuntu 22.04
Queue	AmpereUbuntu
Baseline	28c417f605ba0f04af980847695ec9de470743a0
Compare	659321ff5db13026f52aec70cf2a6692bd4be454
Diff	Diff
Configs	CompilationMode:tiered, LLVM:true, MonoAOT:true, MonoInterpreter:false, RunKind:micro_mono

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector
IndexOfString - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	162.58 ns	178.38 ns	1.10	0.10	False
IndexOfString - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	68.50 ns	73.45 ns	1.07	0.10	False
IndexOfString - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	162.42 ns	178.17 ns	1.10	0.11	False
IndexOfString - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	22.65 ns	28.10 ns	1.24	0.07	False

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector
IndexOfAnyFiveValues - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	2.33 μs	2.85 μs	1.22	0.04	False
IndexOfValue - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	159.71 ns	188.72 ns	1.18	0.12	False
IndexOfAnyFourValues - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	1.94 μs	2.43 μs	1.25	0.04	False
IndexOfAnyFourValues - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	142.23 ns	171.40 ns	1.21	0.04	False
SequenceCompareTo - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	117.62 ns	143.00 ns	1.22	0.25	False
IndexOfAnyFiveValues - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	168.18 ns	197.04 ns	1.17	0.05	False

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector
CallBlockCopy - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	23.00 ns	34.38 ns	1.50	0.27	False
CallBlockCopy - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	24.05 ns	31.72 ns	1.32	0.50	False
CallBlockCopy - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	41.23 ns	104.42 ns	2.53	0.21	False

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio
WriteString - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	648.56 ms	770.55 ms	1.19	0.03	False
WriteCharArray - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	637.80 ms	914.55 ms	1.43	0.03	False

[Perf][Mono] Speed regression in Buffer.BlockCopy across all Mono AOT and WASM configurations on 3/24/2025 4:04:18 PM +00:00 #114696

Description

Run Information

Regressions in System.Memory.ReadOnlySpan

Repro

Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))

ETL Files

Histogram

JIT Disasms

System.Memory.ReadOnlySpan.IndexOfString(input: "Hello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello Worldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylong!xyz", value: "~", comparisonType: Ordinal)

ETL Files

Histogram

JIT Disasms

ETL Files

Histogram

JIT Disasms

System.Memory.ReadOnlySpan.IndexOfString(input: "Hello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello WorldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylongHello Worldbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbareallyreallylong!xyz", value: "w", comparisonType: OrdinalIgnoreCase)

ETL Files

Histogram

JIT Disasms

Docs

Run Information

Regressions in System.Memory.Span<Int32>

Repro

Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))

System.Memory.Span<Int32>.IndexOfAnyFiveValues(Size: 512)

ETL Files

Histogram

JIT Disasms

System.Memory.Span<Int32>.IndexOfValue(Size: 512)

ETL Files

Histogram

JIT Disasms

System.Memory.Span<Int32>.IndexOfAnyFourValues(Size: 512)

ETL Files

Histogram

JIT Disasms

System.Memory.Span<Int32>.IndexOfAnyFourValues(Size: 33)

ETL Files

Histogram

JIT Disasms

System.Memory.Span<Int32>.SequenceCompareTo(Size: 33)

ETL Files

Histogram

JIT Disasms

System.Memory.Span<Int32>.IndexOfAnyFiveValues(Size: 33)

ETL Files

Histogram

JIT Disasms

Docs

Run Information

Regressions in PerfLabTests.BlockCopyPerf

Repro

Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))

PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements: 100)

ETL Files

Histogram

JIT Disasms

PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements: 10)

ETL Files

Histogram

JIT Disasms

PerfLabTests.BlockCopyPerf.CallBlockCopy(numElements: 1000)

ETL Files

Histogram

JIT Disasms

Docs

Run Information

Regressions in System.IO.Tests.Perf_StreamWriter

Repro

Prerequisites (Files either built locally (with build.(sh/cmd) or downloaded from payload above (if same system setup) (in this order))

System.IO.Tests.Perf_StreamWriter.WriteString(writeLength: 100)

ETL Files

Histogram

JIT Disasms

System.IO.Tests.Perf_StreamWriter.WriteCharArray(writeLength: 100)

ETL Files

Histogram

JIT Disasms

Docs