JIT: Assertion failed `(consume == 0) || (ComputeAvailableSrcCount(tree) == consume)` during 'Linear scan register alloc'

[jakobbotsch]

// Generated by Fuzzlyn v2.5 on 2025-03-23 15:25:27
// Run on X86 Windows
// Seed: 916448399438567841-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 63.4 KiB to 0.7 KiB in 00:02:21
// Hits JIT assert in Release:
// Assertion failed '(consume == 0) || (ComputeAvailableSrcCount(tree) == consume)' in 'Program:Main(Fuzzlyn.ExecutionServer.IRuntime)' during 'Linear scan register alloc' (IL size 68; hash 0xade6b36b; FullOpts)
// 
//     File: D:\a\_work\1\s\src\coreclr\jit\lsrabuild.cpp Line: 1776
// 
using System;
using System.Numerics;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;

public class Program
{
    public static byte s_4;
    public static void Main()
    {
        var vr9 = Vector128.Create<ulong>(0);
        var vr10 = (ulong)s_4;
        var vr11 = Vector128.CreateScalar(vr10);
        var vr12 = Avx2.BroadcastScalarToVector128(vr11);
        var vr13 = (byte)0;
        var vr14 = Vector256.CreateScalar(vr13);
        var vr15 = (ulong)Avx2.MoveMask(vr14);
        var vr16 = Vector128.Create<ulong>(vr15);
        var vr17 = Avx512F.VL.TernaryLogic(vr9, vr12, vr16, 1);
        System.Console.WriteLine(vr17);
    }
}

Note that when I try this locally with AltJit (since I don't have an AVX512 CPU) I get a different assert:

Assert failure(PID 34784 [0x000087e0], Thread: 20004 [0x4e24]): Assertion failed 'unreached' in 'Program:Main()' during 'Generate code' (IL size 61; hash 0xcb019401; FullOpts)

    File: C:\dev\dotnet\runtime4\src\coreclr\jit\instr.cpp:1049
    Image: D:\dev\core_roots\16236fdcd417dcfc700e55dd7ae76365ceb7ff87\corerun.exe

I've bisected this to #112728, so I assume the original assert seen by Fuzzlyn is also related to that PR. cc @saucecontrol

cc @dotnet/jit-contrib

[saucecontrol]

Likely related failure seen on #113864

// Generated by Fuzzlyn v2.5 on 2025-03-27 16:58:00
// Run on X86 Windows
// Seed: 10696738320409793384-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 151.7 KiB to 0.8 KiB in 00:02:43
// Hits JIT assert in Release:
// Assertion failed 'hwintrinsicChild->isContained()' in 'Program:Main(Fuzzlyn.ExecutionServer.IRuntime)' during 'Generate code' (IL size 94; hash 0xade6b36b; FullOpts)
// 
//     File: D:\a\_work\1\s\src\coreclr\jit\instr.cpp Line: 903
// 
using System;
using System.Numerics;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;

public class Program
{
    public static ulong s_26;
    public static void Main()
    {
        Vector256<short> vr14 = default(Vector256<short>);
        var vr15 = s_26++;
        var vr16 = Vector128.CreateScalar(vr15);
        var vr17 = Avx2.BroadcastScalarToVector128(vr16);
        var vr18 = Vector128.Create<ulong>(0);
        var vr19 = Vector128.Create<ulong>(0);
        var vr20 = Sse2.ShiftRightLogical128BitLane(vr19, 0);
        var vr21 = Avx512F.VL.PermuteVar2x64x2(vr17, vr18, vr20);
        var vr22 = Vector128.Create<ulong>(0);
        if (Sse41.TestZ(vr21, vr22))
        {
            System.Console.WriteLine(vr14);
        }
    }
}