Assertion failed '!"Qmarks beyond morph disallowed."'

[BruceForstall]

Seen in various libraries jitstress jobs, e.g.

net7.0-Linux-Release-x64-CoreCLR_checked-jitstress2-Ubuntu.1804.Amd64.Open

• System.Collections.Immutable.Tests Work Item
• System.Net.Http.Unit.Tests Work Item

net7.0-windows-Release-x86-CoreCLR_checked-jitstress1-Windows.10.Amd64.Open

• System.Collections.Immutable.Tests Work Item

also arm, arm64

e.g.,

  Starting:    System.Collections.Immutable.Tests (parallel test collections = on, max threads = 4)

Assert failure(PID 5244 [0x0000147c], Thread: 4016 [0x0fb0]): Assertion failed '!"Qmarks beyond morph disallowed."' in 'System.Collections.Immutable.Tests.ImmutableArrayTest:CastUpDelegateToSystemDelegate():this' during 'Morph - Global' (IL size 125; hash 0x3def16f6; FullOpts)

    File: D:\a\_work\1\s\src\coreclr\jit\morph.cpp Line: 15556
    Image: C:\h\w\A43708E8\p\dotnet.exe

@dotnet/jit-contrib

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Issue Details

---

Seen in various libraries jitstress jobs, e.g.

net7.0-Linux-Release-x64-CoreCLR_checked-jitstress2-Ubuntu.1804.Amd64.Open

• System.Collections.Immutable.Tests Work Item
• System.Net.Http.Unit.Tests Work Item

net7.0-windows-Release-x86-CoreCLR_checked-jitstress1-Windows.10.Amd64.Open

• System.Collections.Immutable.Tests Work Item

also arm, arm64

e.g.,

  Starting:    System.Collections.Immutable.Tests (parallel test collections = on, max threads = 4)

Assert failure(PID 5244 [0x0000147c], Thread: 4016 [0x0fb0]): Assertion failed '!"Qmarks beyond morph disallowed."' in 'System.Collections.Immutable.Tests.ImmutableArrayTest:CastUpDelegateToSystemDelegate():this' during 'Morph - Global' (IL size 125; hash 0x3def16f6; FullOpts)

    File: D:\a\_work\1\s\src\coreclr\jit\morph.cpp Line: 15556
    Image: C:\h\w\A43708E8\p\dotnet.exe

@dotnet/jit-contrib

Author:	BruceForstall
Assignees:	-
Labels:	area-CodeGen-coreclr
Milestone:	8.0.0

[EgorBo]

I assume it's #76476 ?

[AndyAyersMS]

I assume it's #76476 ?

Seems quite likely.

[AndyAyersMS]

Suspect it's this

fgMorphTree BB01, STMT00027 (before)
               [000136] -A-X-------                         *  ASG       ref   
               [000135] D------N---                         +--*  LCL_FLD   ref    V11 tmp8         [+0]
               [000123] ---X-------                         \--*  QMARK     ref   
               [000116] -----------    if                      +--*  EQ        int   
               [000114] -----------                            |  +--*  LCL_VAR   ref    V09 tmp6         
               [000115] -----------                            |  \--*  CNS_INT   ref    null
               [000122] ---X-------    if                      \--*  COLON     ref   
               [000120] ---X------- else                          +--*  QMARK     ref   
               [000113] ---X-------    if                         |  +--*  NE        int   
               [000112] #--X-------                               |  |  +--*  IND       long  
               [000110] -----------                               |  |  |  \--*  LCL_VAR   ref    V09 tmp6         
               [000107] H----------                               |  |  \--*  CNS_INT(h) long   0x7f01631dbf20 class
               [000119] -----------    if                         |  \--*  COLON     ref   
               [000117] ----------- else                          |     +--*  LCL_VAR   ref    V09 tmp6         
               [000118] ----------- then                          |     \--*  CNS_INT   ref    null
               [000121] ----------- then                          \--*  LCL_VAR   ref    V09 tmp6 

[EgorBo]

Inlined cast? 🙂

[AndyAyersMS]

Seems like it was from a random inline.