JIT: Assertion failed '(ssize_t)emitCurStackLvl >= argSize'

[amanasifkhalid]

Hit by Antigen on Windows x86. Even after running Trimmer, the repro is quite large: gist.

cc @dotnet/jit-contrib

[jakobbotsch]

Here's a small example:

// Generated by Fuzzlyn v2.2 on 2024-08-06 15:18:34
// Run on X86 Windows
// Seed: 3643678108487993466-vectort,vector128,vector256,x86aes,x86avx,x86avx2,x86avx512bw,x86avx512bwvl,x86avx512cd,x86avx512cdvl,x86avx512dq,x86avx512dqvl,x86avx512f,x86avx512fvl,x86bmi1,x86bmi2,x86fma,x86lzcnt,x86pclmulqdq,x86popcnt,x86sse,x86sse2,x86sse3,x86sse41,x86sse42,x86ssse3,x86x86base
// Reduced from 55.7 KiB to 0.5 KiB in 00:02:02
// Hits JIT assert in Release:
// Assertion failed '(ssize_t)emitCurStackLvl >= argSize' in 'Program:Main(Fuzzlyn.ExecutionServer.IRuntime)' during 'Generate code' (IL size 32; hash 0xade6b36b; FullOpts)
// 
//     File: D:\a\_work\1\s\src\coreclr\jit\emitxarch.cpp Line: 9937
// 
using System;
using System.Runtime.CompilerServices;
using System.Numerics;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;

public struct S1
{
    public double F0;
    public Vector256<short> F1;
    public S1(bool f3) : this()
    {
    }
}

public class Program
{
    public static void Main()
    {
        S1[][, ] vr0 = new S1[][, ]
        {
            new S1[, ]
            {
                {
                    new S1(false)
                }
            }
        };
    }
}

[JulieLeeMSFT]

@TIHan, PTAL. Assert in Generate Code.

[TIHan]

Able to reproduce the issue, am looking into it.