JIT: Assertion failed '!m_rootNode->OperIsLocal() && !m_rootNode->OperIsLocalAddr()' during 'Morph - Structs/AddrExp'

[jakobbotsch]

// Generated by Fuzzlyn v1.5 on 2023-01-22 16:00:16
// Run on Arm64 Windows
// Seed: 17286164302317655577
// Reduced from 117.6 KiB to 0.4 KiB in 00:02:13
// Hits JIT assert in Release:
// Assertion failed '!m_rootNode->OperIsLocal() && !m_rootNode->OperIsLocalAddr()' in 'Program:Main(Fuzzlyn.ExecutionServer.IRuntime)' during 'Morph - Structs/AddrExp' (IL size 83; hash 0xade6b36b; FullOpts)
// 
//     File: D:\a\_work\1\s\src\coreclr\jit\lclmorph.cpp Line: 34
// 
public interface I0
{
}

public struct S0 : I0
{
    public sbyte F0;
    public S0 M17(I0 arg0, ulong arg1)
    {
        return this;
    }
}

public class Program
{
    public static ulong s_2;
    public static void Main()
    {
        var vr6 = new S0();
        var vr7 = new S0();
        new S0().M17(new S0().M17(vr7, 0).M17(vr6, s_2), s_2);
    }
}

We end up with:

LocalAddressVisitor visiting statement:
STMT00012 ( ??? ... ??? )
               [000077] n--X-------                         ▌  IND       byte  
               [000076] -----------                         └──▌  LCL_VAR_ADDR byref  V03 loc3         
                                                            └──▌    byte   V03.S0:F0 (offs=0x00) -> V12 tmp8         
Replacing the field in promoted struct with local var V12

This gives a standalone top-level LCL_VAR node and the locals linking assumes that these cannot exist.

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Issue Details

---

// Generated by Fuzzlyn v1.5 on 2023-01-22 16:00:16
// Run on Arm64 Windows
// Seed: 17286164302317655577
// Reduced from 117.6 KiB to 0.4 KiB in 00:02:13
// Hits JIT assert in Release:
// Assertion failed '!m_rootNode->OperIsLocal() && !m_rootNode->OperIsLocalAddr()' in 'Program:Main(Fuzzlyn.ExecutionServer.IRuntime)' during 'Morph - Structs/AddrExp' (IL size 83; hash 0xade6b36b; FullOpts)
// 
//     File: D:\a\_work\1\s\src\coreclr\jit\lclmorph.cpp Line: 34
// 
public interface I0
{
}

public struct S0 : I0
{
    public sbyte F0;
    public S0 M17(I0 arg0, ulong arg1)
    {
        return this;
    }
}

public class Program
{
    public static ulong s_2;
    public static void Main()
    {
        var vr6 = new S0();
        var vr7 = new S0();
        new S0().M17(new S0().M17(vr7, 0).M17(vr6, s_2), s_2);
    }
}

We end up with:

LocalAddressVisitor visiting statement:
STMT00012 ( ??? ... ??? )
               [000077] n--X-------                         ▌  IND       byte  
               [000076] -----------                         └──▌  LCL_VAR_ADDR byref  V03 loc3         
                                                            └──▌    byte   V03.S0:F0 (offs=0x00) -> V12 tmp8         
Replacing the field in promoted struct with local var V12

This gives a standalone top-level LCL_VAR node and the locals linking assumes that these cannot exist.

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