[ci-scan] Test failure: GitHub_19288 JIT assert genActualType mismatch in Morph under MinOpts stress

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Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1444990
Build error leg or test failing: coreclr Pri1 Runtime Tests Run windows x64 checked - Regression_do

Error Details

Assert failure(PID 5756 [0x0000167c], Thread: 5764 [0x1684]): Assertion failed 'genActualType(cmp->gtGetOp1()) == genActualType(cmp->gtGetOp2())' in 'GitHub_19288.GitHub_19288+MyClass:CheckPointer(GitHub_19288.GitHub_19288+PixelData):this' during 'Morph - Global' (IL size 24; hash 0x7f12b01d; MinOpts)

    File: D:\a\_work\1\s\src\coreclr\jit\morph.cpp:10962
    Image: corerun.exe

Exit Code: -1073740286
Expected: 100
Actual: -1073740286
END EXECUTION - FAILED

Stress mode: DOTNET_TieredCompilation=0, DOTNET_JITMinOpts=1

Error Message

true only for clear infra flakes. ExcludeConsoleLog skips helix log scanning. -->

{
  "ErrorMessage": "Assertion failed 'genActualType(cmp->gtGetOp1()) == genActualType(cmp->gtGetOp2())'",
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Additional context

• Pipeline: runtime-coreclr jitstress (definition 109)
• Queue: windows.10.amd64.open
• Work item: Regression_do
• First seen in build 1444990 (finished 2026-06-02T07:13:06Z)
• Occurrences: 2 builds (1444990, 1447151)
• Not present in builds 1442839 (2026-06-01) or 1442384 (2026-05-31)

Related: An in-flight fix PR may address this: #128935

---

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Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
0	0	0

[EgorBo]

@BoyBaykiller seems to be a regression by one of your recent PRs

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[BoyBaykiller]

seems to be a regression by one of your recent PRs

Specifically #128091. You can assign me.
Failing tree is:

*  NE        int   
+--*  LCL_VAR   byref  V01 arg1         
\--*  CAST      long <- ulong <- uint
   \--*  CNS_INT   int    0

[AndyAyersMS]

I'll keep on as co-assignee.

Blocking clean-ci means this is potentially a high-impact issue. We may consider reverting the original change if we can't find a fix quickly.

[BoyBaykiller]

This should be an easy fix. If I understand correctly the assert thats failing is supposed to be a general IR validation check, rather than a function specific assumption that must be true: https://discord.com/channels/143867839282020352/312132327348240384/1507906522104074260

The current assert is:

assert(genActualType(cmp->gtGetOp1()) == genActualType(cmp->gtGetOp2()));

But apparently we can see compares with byref+long for example. So we could just update it to reflect that, or remove it.