JIT: fix unused operand marking in LowerHWIntrinsicTernaryLogic

In `LowerHWIntrinsicTernaryLogic` we do some operand swapping and replacing, and were not accounting for this when marking operands as unused. Fixes #106480.
dotnet · Aug 17, 2024 · 4087182 · 4087182
1 parent 63c9565
commit 4087182
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Showing 3 changed files with 42 additions and 3 deletions.
diff --git a/src/coreclr/jit/lowerxarch.cpp b/src/coreclr/jit/lowerxarch.cpp
@@ -3975,7 +3975,7 @@ GenTree* Lowering::LowerHWIntrinsicTernaryLogic(GenTreeHWIntrinsic* node)
 
                         if (!op1->IsCnsVec())
                         {
-                            op1->SetUnusedValue();
+                            node->Op(1)->SetUnusedValue();
                             op1 = comp->gtNewZeroConNode(simdType);
 
                             BlockRange().InsertBefore(node, op1);
@@ -3984,7 +3984,7 @@ GenTree* Lowering::LowerHWIntrinsicTernaryLogic(GenTreeHWIntrinsic* node)
 
                         if (!op2->IsCnsVec())
                         {
-                            op2->SetUnusedValue();
+                            node->Op(2)->SetUnusedValue();
                             op2 = comp->gtNewZeroConNode(simdType);
 
                             BlockRange().InsertBefore(node, op2);
@@ -3997,7 +3997,7 @@ GenTree* Lowering::LowerHWIntrinsicTernaryLogic(GenTreeHWIntrinsic* node)
                     {
                         if (!op1->IsCnsVec())
                         {
-                            op1->SetUnusedValue();
+                            node->Op(1)->SetUnusedValue();
                             op1 = comp->gtNewZeroConNode(simdType);
 
                             BlockRange().InsertBefore(node, op1);

diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_106480/Runtime_106480.cs b/src/tests/JIT/Regression/JitBlue/Runtime_106480/Runtime_106480.cs
@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+// Found by Antigen
+// Reduced from 121.36 KB to 3.38 
+// Further redued by hand
+
+using System;
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.X86;
+using Xunit;
+
+public class Runtime_106480
+{
+    Vector512<ushort> v512_ushort_102 = Vector512<ushort>.AllBitsSet;
+
+    void Problem()
+    {
+        if (Avx512F.IsSupported)
+        {
+            byte byte_126 = 5;
+            Avx512F.TernaryLogic(v512_ushort_102, v512_ushort_102, v512_ushort_102, byte_126);
+        }
+    }
+
+    [Fact]
+    public static void Test()
+    {
+        new Runtime_106480().Problem();
+    }
+}
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_106480/Runtime_106480.csproj b/src/tests/JIT/Regression/JitBlue/Runtime_106480/Runtime_106480.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>