Assertion failed '!"Found mismatched live reg var(s) after block"'

[BruceForstall]

Failure in libraries : release libraries, checked coreclr with:

COMPlus_TieredCompilation=0

Linux arm64

Test run:
https://dev.azure.com/dnceng/public/_build/results?buildId=684206&view=ms.vss-test-web.build-test-results-tab&runId=21225922&paneView=debug

Test failure log:
https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-pull-36486-head-d5714f8ce6f1441899/System.Numerics.Vectors.Tests/console.7242eda3.log?sv=2019-02-02&se=2020-07-02T05%3A16%3A13Z&sr=c&sp=rl&sig=evj7TkbtH4HSaFgzC2LHLZvlPgemFMrsYoAxg9pngWE%3D

+ export COMPlus_TieredCompilation=0
+ export COMPlus_DbgEnableMiniDump=1
+ export COMPlus_DbgMiniDumpName=/home/helixbot/dotnetbuild/dumps/coredump.%d.dmp
+ printenv
+ grep COMPlus
COMPlus_TieredCompilation=0
COMPlus_DbgMiniDumpName=/home/helixbot/dotnetbuild/dumps/coredump.%d.dmp
COMPlus_DbgEnableMiniDump=1
+ ./RunTests.sh --runtime-path /root/helix/work/correlation
----- start Fri Jun 12 09:43:36 UTC 2020 =============== To repro directly: =====================================================
pushd .
/root/helix/work/correlation/dotnet exec --runtimeconfig System.Numerics.Vectors.Tests.runtimeconfig.json --depsfile System.Numerics.Vectors.Tests.deps.json xunit.console.dll System.Numerics.Vectors.Tests.dll -xml testResults.xml -nologo -nocolor -notrait category=IgnoreForCI -notrait category=OuterLoop -notrait category=failing 
popd
===========================================================================================================
/root/helix/work/workitem /root/helix/work/workitem
  Discovering: System.Numerics.Vectors.Tests (method display = ClassAndMethod, method display options = None)
  Discovered:  System.Numerics.Vectors.Tests (found 1195 test cases)
  Starting:    System.Numerics.Vectors.Tests (parallel test collections = on, max threads = 4)

Assert failure(PID 133 [0x00000085], Thread: 146 [0x0092]): Assertion failed '!"Found mismatched live reg var(s) after block"' in 'System.Numerics.Tests.Vector4Tests:Vector4TransformVector4QuaternionTest():this' during 'Generate code' (IL size 177)

    File: /__w/1/s/src/coreclr/src/jit/codegenlinear.cpp Line: 602
    Image: /root/helix/work/correlation/dotnet

[BruceForstall]

@dotnet/jit-contrib

[CarolEidt]

@BruceForstall - this passes locally for me. Without #37781, though, I was only getting the same varReg != REG_NA assert as in #37761 with and without COMPlus_TieredCompilation. So I can't be entirely confident that it was the same issue. I've got another PR #37773 to fix a jitstressregs issue on arm64 - would it make sense to run the runtime-coreclr libraries-jitstress leg on that? (I've just rebased it to include the fix in #37781)

[BruceForstall]

You can't run that runtime-coreclr libraries-jitstress job yet since I haven't merged the change to enable it (#36486). I'll see if I can repro. But otherwise, I only saw this in one run. Perhaps ignore it for now and if it doesn't repro in subsequent runs I'll close this.

[CarolEidt]

@BruceForstall - has this surfaced again?

[BruceForstall]

I don't see it in last night's scheduled run, https://dev.azure.com/dnceng/public/_build/results?buildId=693458&view=ms.vss-test-web.build-test-results-tab, so closing.