JIT: don't clone loops where init or limit is a cast local

[AndyAyersMS]

The loop cloner assumes all computations it introduces are compatible
with TYP_INT, so don't allow cloning when the initial or final value
are variables with incompatible types.

Fixes #57535.

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Issue Details

---

The loop cloner assumes all computations it introduces are compatible
with TYP_INT, so don't allow cloning when the initial or final value
are variables with incompatible types.

Fixes #57535.

Author:	AndyAyersMS
Assignees:	-
Labels:	area-CodeGen-coreclr
Milestone:	-

[AndyAyersMS]

cc @dotnet/jit-contrib @SingleAccretion

No SPMI diffs.

We will want to port this to .NET 6.

[kunalspathak]

LGTM. I am surprised that none of our test had this scenario.

[SingleAccretion]

Question: do we think this is a cloning-exclusive issue? In relation to not setting the relevant loop flags in the first place (somewhere around optRecordLoop).

I suppose literally nothing but cloning uses this information today so it does not matter either way.

[AndyAyersMS]

Question: do we think this is a cloning-exclusive issue? In relation to not setting the relevant loop flags in the first place (somewhere around optRecordLoop).

I suppose literally nothing but cloning uses this information today so it does not matter either way.

Probably best to keep the fix surgical for .NET 6.

But we should look and see if anything else might be tripped up.

[AndyAyersMS]

Linux failures seems like some sort of test issue with crossgen2 testing:

;; crossgen2determinism.sh

Unhandled exception. System.AggregateException: One or more errors occurred. (Code generation failed for method '[crossgen2smoke]Program.TestSES_NestedU8(SingleElementStruct_NestedU8,object)') (Code generation failed for method '[crossgen2smoke]Program.TestSES_NestedR8(SingleElementStruct_NestedR8,object)')
---> ILCompiler.CodeGenerationFailedException: Code generation failed for method '[crossgen2smoke]Program.TestSES_NestedU8(SingleElementStruct_NestedU8,object)'
---> System.MissingMethodException: Method not found: 'Void System.Diagnostics.Debug.Assert(Boolean, AssertInterpolatedStringHandler)'.

@trylek seen anything like this recently?

[hoyosjs]

@AndyAyersMS yes, it's been reported in a few cases. Issue: #57620

[AndyAyersMS]

Mono interpreter failure looks real but is unrelated.

   Loader.classloader.XUnitWrapper: [Long Running Test] 'Loader/classloader/regressions/523654/test532654_b/test532654_b.sh', Elapsed: 00:08:08
Attempting to collect crash dump: /home/helixbot/dotnetbuild/dumps/crashdump_269.dmp
Invoking: sudo /root/helix/work/correlation/createdump --name "/home/helixbot/dotnetbuild/dumps/crashdump_269.dmp" 269 --withheap
createdump stdout:
Gathering state for process 269 corerun

createdump stderr:
CLRDataCreateInstance(ICLRDataEnumMemoryRegions) FAILED 80131c4f

Failed to collect crash dump
    Loader/classloader/regressions/523654/test532654_b/test532654_b.sh [FAIL]
      corrupted double-linked list

        Got a SIGABRT while executing native code. This usually indicates
        a fatal error in the mono runtime or one of the native libraries 
        used by your application

Does not seem to be a known issue? cc @BrzVlad

[AndyAyersMS]

/backport to release/6.0

[github-actions]

Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/1144484614

[AndyAyersMS]

/backport to release/6.0-rc1

[github-actions]

Started backporting to release/6.0-rc1: https://github.com/dotnet/runtime/actions/runs/1144633915