Ensure that NI_SSE2_Extract and NI_SSE41_Extract are simdSize=16

Author: tannergooding

src/coreclr/jit/lowerxarch.cpp

@@ -7875,7 +7875,8 @@ void Lowering::ContainCheckStoreIndir(GenTreeStoreInd* node)
                     // However, we want to prefer containing the store over allowing the
                     // input to be regOptional, so track and clear containment if required.
 
-                    clearContainedNode = hwintrinsic->Op(1);
+                    GenTree* op1       = hwintrinsic->Op(1);
+                    clearContainedNode = op1;
                     isContainable      = !clearContainedNode->isContained();
 
                     if (isContainable && varTypeIsIntegral(simdBaseType))
@@ -7887,13 +7888,29 @@ void Lowering::ContainCheckStoreIndir(GenTreeStoreInd* node)
                         if (isContainable && varTypeIsSmall(simdBaseType))
                         {
                             CorInfoType baseJitType = varTypeIsByte(node) ? CORINFO_TYPE_UBYTE : CORINFO_TYPE_USHORT;
-                            intrinsicId             = varTypeIsByte(node) ? NI_SSE41_Extract : NI_SSE2_Extract;
+
+                            if (intrinsicId == NI_Vector512_ToScalar)
+                            {
+                                op1 = comp->gtNewSimdHWIntrinsicNode(TYP_SIMD16, op1, NI_Vector512_GetLower128,
+                                                                     baseJitType, 64);
+                                BlockRange().InsertBefore(hwintrinsic, op1);
+                                LowerNode(op1);
+                            }
+                            else if (intrinsicId == NI_Vector256_ToScalar)
+                            {
+                                op1 = comp->gtNewSimdGetLowerNode(TYP_SIMD16, op1, baseJitType, 32);
+                                BlockRange().InsertBefore(hwintrinsic, op1);
+                                LowerNode(op1);
+                            }
+
+                            intrinsicId = varTypeIsByte(node) ? NI_SSE41_Extract : NI_SSE2_Extract;
 
                             GenTree* zero = comp->gtNewZeroConNode(TYP_INT);
                             BlockRange().InsertBefore(hwintrinsic, zero);
 
                             hwintrinsic->SetSimdBaseJitType(baseJitType);
-                            hwintrinsic->ResetHWIntrinsicId(intrinsicId, hwintrinsic->Op(1), zero);
+                            hwintrinsic->SetSimdSize(16);
+                            hwintrinsic->ResetHWIntrinsicId(intrinsicId, op1, zero);
                             zero->SetContained();
                         }
                     }

src/tests/JIT/Regression/JitBlue/Runtime_115493/Runtime_115493.cs

@@ -0,0 +1,38 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Numerics;
+using System.Runtime.CompilerServices;
+using Xunit;
+
+public class Runtime_115493
+{
+    [Fact]
+    public static void Problem()
+    {
+        int checksum = 44444;
+        int exitCode = 100;
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        int ProcessValue(object val)
+        {
+            return val switch
+            {
+                int i => i,
+                short s => s,
+                _ => 0
+            };
+        }
+
+        var a = new Vector<short>(25);
+        a = Vector.SquareRoot(a);
+        checksum = unchecked(checksum + ProcessValue(a[0]));
+        if (a[0] != 5)
+        {
+            exitCode = 0;
+        }
+
+        Assert.Equal(44449, checksum);
+        Assert.Equal(100, exitCode);
+    }
+}

src/tests/JIT/Regression/JitBlue/Runtime_115493/Runtime_115493.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>