Ignore always-true relops in optRelopTryInferWithOneEqualOperand (#117749)

Author: EgorBo

src/coreclr/jit/redundantbranchopts.cpp

@@ -688,6 +688,15 @@ bool Compiler::optRelopTryInferWithOneEqualOperand(const VNFuncApp&      domApp,
 
     if ((ifTrueStatus == RelopResult::Unknown) && (ifFalseStatus == RelopResult::Unknown))
     {
+        JITDUMP("Can't infer from both true and false branches - bail out.\n")
+        return false;
+    }
+
+    if ((ifTrueStatus == RelopResult::AlwaysTrue) && (ifFalseStatus == RelopResult::AlwaysTrue))
+    {
+        // If it doesn't depend on the dominating relop - bail out, someone else will fold
+        // this always-true condition.
+        JITDUMP("Always true from both branches - bail out.\n")
         return false;
     }
 

src/tests/JIT/Regression/JitBlue/Runtime_116159/Runtime_116159.cs

@@ -0,0 +1,41 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+// Generated by Fuzzlyn v3.1 on 2025-05-30 09:55:02
+// Run on Arm64 MacOS
+// Seed: 17657029378323677877-vectort,vector64,vector128,armadvsimd,armadvsimdarm64,armaes,armarmbase,armarmbasearm64,armcrc32,armcrc32arm64,armdp,armrdm,armrdmarm64,armsha1,armsha256
+// Reduced from 183.5 KiB to 0.6 KiB in 00:00:39
+// Debug: Prints 0 line(s)
+// Release: Prints 1 line(s)
+
+using System;
+using Xunit;
+
+public class Runtime_116159
+{
+    public static long[] s_3 = new long[]
+    {
+        0
+    };
+    public static int s_6;
+    public static ulong[] s_9;
+
+    [Fact]
+    public static void TestEntryPoint()
+    {
+        if (1 <= s_3[0])
+        {
+            s_9 = new ulong[]
+            {
+                0
+            };
+        }
+        else
+        {
+            if (long.MinValue > s_3[0])
+            {
+                throw new Exception();
+            }
+        }
+    }
+}

src/tests/JIT/Regression/JitBlue/Runtime_116159/Runtime_116159.csproj

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