Description

Vector3.Cross with parallel vectors produce different results within .NET 8 and .NET 9

Reproduction Steps

using System.Numerics;

var v = new Vector3(-1, 1, 0);
var n = Vector3.Normalize(v);
var c = Vector3.Cross(n, n);
System.Diagnostics.Debug.Assert(c == Vector3.Zero);

Expected behavior

c is Vector3.Zero

Actual behavior

c is non-zero(new Vector3(0,0,1.26880515E-08f))

Regression?

This is regression from .NET 9

Known Workarounds

No response

Configuration

• cpu: AMD Ryzen 7 5800H
• architecture: x64

Other information

• relevent changes:
  • Additional cleanup and acceleration of the System.Numerics vector and related types #103527
  • Cross Product for Vector2 and Vector4 #111265