Test failure: Assertion failed 'topBB->bbNum <= botBB->bbNum'

[v-haren]

failed in job: runtime-coreclr jitstress2-jitstressregs 20200926.1

failed tests:
JIT\Methodical\tailcall\_il_reldeep_array_nz\_il_reldeep_array_nz.cmd
JIT\Methodical\tailcall\_il_reldeep_inst\_il_reldeep_inst.cmd
JIT\Methodical\tailcall\_il_reldeep_gc\_il_reldeep_gc.cmd
JIT\Methodical\tailcall\_il_reldeep_virt\_il_reldeep_virt.cmd
JIT\Methodical\VT\callconv\_il_reljumps3\_il_reljumps3.cmd
JIT\Methodical\VT\callconv\_il_reljumps2\_il_reljumps2.cmd
JIT/Methodical/VT/callconv/_il_reljumps3/_il_reljumps3.sh
JIT/Methodical/VT/callconv/_il_reljumps2/_il_reljumps2.sh
JIT\jit64\mcc\interop\mcc_i37\mcc_i37.cmd
JIT\Regression\JitBlue\GitHub_23147\GitHub_23147\GitHub_23147.cmd
JIT\jit64\mcc\interop\mcc_i77\mcc_i77.cmd
JIT\Methodical\tailcall\_il_reldeep_value\_il_reldeep_value.cmd
JIT\Methodical\tailcall\_il_reldeep_array\_il_reldeep_array.cmd
JIT\Methodical\VT\callconv\_il_reljumper4\_il_reljumper4.cmd
JIT\jit64\mcc\interop\mcc_i87\mcc_i87.cmd
JIT/Regression/VS-ia64-JIT/V1.2-M02/b14364/b14364/b14364.sh
JIT\Regression\VS-ia64-JIT\V1.2-M02\b14364\b14364\b14364.cmd

Error message

Assert failure(PID 4460 [0x0000116c], Thread: 4948 [0x1354]): Assertion failed 'topBB->bbNum <= botBB->bbNum' in 'JitTest.TestClass:Method11():System.String:this' during 'Set block order' (IL size 34)

    File: F:\workspace\_work\1\s\src\coreclr\src\jit\optimizer.cpp Line: 3935
    Image: C:\h\w\C33C0A68\p\CoreRun.exe


Return code:      1
Raw output file:      C:\h\w\C33C0A68\w\AB16094C\e\JIT\Methodical\Reports\JIT.Methodical\tailcall\_il_reldeep_inst\_il_reldeep_inst.output.txt
Raw output:
BEGIN EXECUTION
 "C:\h\w\C33C0A68\p\corerun.exe" _il_reldeep_inst.dll 
Expected: 100
Actual: -1073740286
END EXECUTION - FAILED
FAILED
Test Harness Exitcode is : 1
To run the test:
> set CORE_ROOT=C:\h\w\C33C0A68\p
> C:\h\w\C33C0A68\w\AB16094C\e\JIT\Methodical\tailcall\_il_reldeep_inst\_il_reldeep_inst.cmd
Expected: True
Actual:   False


Stack trace
   at JIT_Methodical._tailcall__il_reldeep_inst__il_reldeep_inst_._tailcall__il_reldeep_inst__il_reldeep_inst_cmd() in F:\workspace\_work\1\s\artifacts\tests\coreclr\Windows_NT.x64.Checked\TestWrappers\JIT.Methodical\JIT.Methodical.XUnitWrapper.cs:line 180851

[BruceForstall]

@dotnet/jit-contrib JIT assertion regression in jitstress2 run, especially 4 tailcall tests.

[BruceForstall]

@dotnet/jit-contrib This is still causing many jobs to fail

[erozenfeld]

I haven't investigated this but my guess is that this is likely caused by removal of this line

runtime/src/coreclr/src/jit/compiler.cpp

Line 4660 in 5c8e3f8

fgRenumberBlocks();

in my #42664.

[briansull]

I will take a look

[briansull]

The GS Cookie phase was inserting a new basic block and (indirectly) depending upon the call to fgRenumberBlocks that Eugene removed. I will add a renuimber bloicks call to the GS Cookie phase if it can insert a new basic block.

I am testing a fix.

[BruceForstall]

This should be fixed by #43077