Ensure that embedded broadcast is correctly checking for EVEX support before use (#105659)

* Ensure that embedded broadcast is correctly checking for EVEX support before use

* Only run the test if Avx is supported

Author: tannergooding

src/coreclr/jit/lowerxarch.cpp

@@ -8292,7 +8292,7 @@ bool Lowering::IsContainableHWIntrinsicOp(GenTreeHWIntrinsic* parentNode, GenTre
                 return false;
             }
 
-            return parentNode->OperIsEmbBroadcastCompatible();
+            return parentNode->OperIsEmbBroadcastCompatible() && comp->canUseEvexEncoding();
         }
 
         default:

src/tests/JIT/Regression/JitBlue/Runtime_96156/Runtime_96156.cs

@@ -0,0 +1,34 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.X86;
+using System.Runtime.CompilerServices;
+using Xunit;
+
+public class Runtime_96156
+{
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private unsafe static Vector128<float> BroadcastScalarToVector128(float value)
+    {
+        return Avx.BroadcastScalarToVector128(&value);
+    }
+
+    [Fact]
+    public static void TestEntryPoint()
+    {
+        if (Avx.IsSupported)
+        {
+            Vector128<float> c = Vector128.Create(1.0f);
+            Vector128<float> r = Problem(2.0f, 0.5f, c);
+            Assert.Equal(Vector128.Create(4.0f), r);
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static Vector128<float> Problem(float a, float b, Vector128<float> c)
+    {
+        return Avx.Multiply(c, BroadcastScalarToVector128(a / b));
+    }
+}

src/tests/JIT/Regression/JitBlue/Runtime_96156/Runtime_96156.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <CLRTestEnvironmentVariable Include="DOTNET_EnableAVX512F" Value="0" />
+    <CLRTestEnvironmentVariable Include="DOTNET_TieredCompilation" Value="0" />
+  </ItemGroup>
+</Project>