using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.Intrinsics;

// (1) works fine if `MethodImplOptions.AggressiveOptimization` is disabled
[MethodImpl(MethodImplOptions.AggressiveOptimization)]
void Main()
{
    var data = new int[] { 0, 0, 0, 0, 0, 0, 0, 0 };
    var span = data.AsSpan();

    // (2) works fine if replace Random.Shared.Next() to literal
    // var vecTmp = Vector256.Create(0x1234);
    var vecTmp = Vector256.Create(Random.Shared.Next());

    // xor generates 0, however, `vec0` has wrong values after loop.
    // (3-a) works fine if use `Vector256<int>.Zero`
    // var vec0 = Vector256<int>.Zero;
    var vec0 = vecTmp ^ vecTmp;

    for (var elementOffset = 0; elementOffset < span.Length; elementOffset += Vector256<int>.Count)
    {
        var vec = Vector256.LoadUnsafe(ref MemoryMarshal.GetReference(span), (nuint)elementOffset);

        // (3-b) data will be OK if use`Vector256<int>.Zero` directly here
        var vecIsZero = Vector256.Equals<int>(vec, vec0);
        // var vecIsZero = Vector256.Equals<int>(vec, Vector256<int>.Zero);
        vecIsZero.StoreUnsafe(ref MemoryMarshal.GetReference(span), (nuint)elementOffset);
    }

    // (4) works fine if vecTmp is refered
    // Console.WriteLine($"{vecTmp}");

    // expected: True
    // actual  : False
    Console.WriteLine(vec0.Equals(Vector256<int>.Zero));

    // expected: <0, 0, 0, 0, 0, 0, 0, 0>
    // actual: <same random value> ... has random values it might be `vecTmp`
    Console.WriteLine(vec0);

    // expected: <-1, -1, -1, -1, -1, -1, -1, -1>
    // actual  : <0, 0, 0, 0, 0, 0, 0, 0>
    Console.WriteLine(Vector256.Create(data));
}

Main();