[Perf] Linux/x64: 2 Improvements on 7/5/2026 2:44:21 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [986fba00d9f89d2dfb8ac440bf37727a18828f64](https://github.com/dotnet/runtime/commit/986fba00d9f89d2dfb8ac440bf37727a18828f64)
Compare | [8f365c934088b8ae21a4dfce8073da0d3eb22a54](https://github.com/dotnet/runtime/commit/8f365c934088b8ae21a4dfce8073da0d3eb22a54)
Diff | [Diff](https://github.com/dotnet/runtime/compare/986fba00d9f89d2dfb8ac440bf37727a18828f64...8f365c934088b8ae21a4dfce8073da0d3eb22a54)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Tests.Perf_String

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|

• [Split_Csv - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 4.60 ms | 3.86 ms | 0.84 | 0.13 | False | | |
|

• [Split_Csv - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 1.68 ms | 1.46 ms | 0.87 | 0.27 | False | | |

![graph]()
![graph]()
[Test Report]()

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

```cmd
git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Tests.Perf_String*'
```

### System.Tests.Perf_String.Split_Csv(testName: "Short Text", lines: ["Year,quarter,Bene_Geo_Desc,Bene_Mdcd_Mdcr_Enrl_Stus,Bene_Race_Desc,Bene_Sex_Desc,Bene_Mdcr_Entlmt_Stus,Bene_Age_Desc,Bene_RUCA_Desc,Total_Bene_TH_Elig,Total_PartB_Enrl,Total_Bene_Telehealth,Pct_Telehealth", "2020,Overall,National,All,All,All,All,All,All,30946785,32244893.5,14826919,0.4791", "2020,Overall,National,All,All,All,All,All,Rural,7179538,7490300.6667,2858284,0.3981", "2020,Overall,National,All,All,All,All,All,Urban,23696871,24629142.917,11944230,0.504", "2020,Overall,National,All,All,All,All,All,Unknown,,,,", ...])

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_String.Split_Csv(testName: "Short Mixed", lines: ["id,state,value,date,fuel_type,fuel_type_code,fips,abbrev", "34_1_2012_1,New Jersey,310548576,01/01/2012 12:00:00 AM,Gasoline/gasohol,1,34,NJ", "35_1_2012_1,New Mexico,74048088,01/01/2012 12:00:00 AM,Gasoline/gasohol,1,35,NM", "36_1_2012_1,New York,492654272,01/01/2012 12:00:00 AM,Gasoline/gasohol,1,36,NY", "37_1_2012_1,North Carolina,328735168,01/01/2012 12:00:00 AM,Gasoline/gasohol,1,37,NC", ...])

#### 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)

Start with the benchmark source in src/benchmarks/micro/libraries/System.Runtime/Perf.String.cs at lines 323-337, then run the documented benchmarks_ci.py command with the System.Tests.Perf_String filter. Compare the Short Text and Short Mixed results with the linked reports; the issue does not specify a code change or acceptance criteria, so triage must establish what completion means.

Written by the indexing model from the issue text.