JIT: Avx.CompareScalar incorrectly folded with True/False comparison modes #125160
Description
Description
CompareScalar is supposed to return the upper elements of the first operand unchanged, but folding for True/False comparison modes returns a full Zero or AllBitsSet vector.
Reproduction Steps
using System.Runtime.CompilerServices;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;
Console.WriteLine(CompareFalse(Vector128<float>.One, Vector128<float>.Zero));
[MethodImpl(MethodImplOptions.NoInlining)]
static Vector128<float> CompareFalse(Vector128<float> x, Vector128<float> y)
=> Avx.CompareScalar(x, y, FloatComparisonMode.OrderedFalseSignaling);Expected behavior
> dotnet run -c release -f net9.0<0, 1, 1, 1>
Actual behavior
> dotnet run -c release -f net10.0<0, 0, 0, 0>
Regression?
Yes
Known Workarounds
No response
Configuration
No response
Other information
No response