RoslynCompiler

Simple RoslynCompiler benchmark. I'm currently switching a project to Roslyn and startup performance (mainly due to JIT compilation) is an issue on that tool (compared to previous compiler). I've tried several versions of Roslyn and I have inconsistent results. Right now I'm focusing on benchmarking performances for different .NET Framework versions.

I'm using multicore JIT to improve startup time.

On this sample I'm using latest Roslyn NuGet package (currently 2.1.0)

Instructions

Open RoslynComparer.sln with Visual Studio 2017 and launch Comparer project.

Here are the results on my computer:

== Run Roslyn Compiler with .NET Framework 4.6 ==
 Creating startup profile:
  Compilation time: 1007 ms  Execution time: 1120 ms
 Use startup profile:
  Compilation time: 694 ms  Execution time: 785 ms
  Compilation time: 612 ms  Execution time: 714 ms
  Compilation time: 634 ms  Execution time: 726 ms

== Run Roslyn Compiler with .NET Framework 4.6.1 ==
 Creating startup profile:
  Compilation time: 961 ms  Execution time: 1069 ms
 Use startup profile:
  Compilation time: 646 ms  Execution time: 740 ms
  Compilation time: 645 ms  Execution time: 741 ms
  Compilation time: 605 ms  Execution time: 699 ms

== Run Roslyn Compiler with .NET Framework 4.6.2 ==
 Creating startup profile:
  Compilation time: 2223 ms  Execution time: 2346 ms
 Use startup profile:
  Compilation time: 1395 ms  Execution time: 1510 ms
  Compilation time: 1406 ms  Execution time: 1518 ms
  Compilation time: 1390 ms  Execution time: 1500 ms

== Run Roslyn Compiler with .NET Framework 4.7 ==
 Creating startup profile:
  Compilation time: 2199 ms  Execution time: 2325 ms
 Use startup profile:
  Compilation time: 1437 ms  Execution time: 1546 ms
  Compilation time: 1367 ms  Execution time: 1485 ms
  Compilation time: 1355 ms  Execution time: 1465 ms

As you can see it's much slower with .NET framework 4.6.2 and 4.7.

Remarks

• I tried UseLegacyJIT in app.config but it resulted in worse performance (as we could have expected)

<runtime>
      <useLegacyJit enabled="1" />
 </runtime>

• Tracing with WPA confirmed me the JIT time is really slower with 4.6.2