4 files changed, 91 insertions, 0 deletions
diff --git a/tests/arm/Tests.lst b/tests/arm/Tests.lst
index 964d7460b7..1456113d4f 100644
--- a/tests/arm/Tests.lst
+++ b/tests/arm/Tests.lst
@@ -94619,3 +94619,11 @@ Expected=0
 MaxAllowedDurationSeconds=600
 Categories=EXPECTED_PASS
 HostStyle=0
+
+[GitHub_19397.cmd_11916]
+RelativePath=JIT\Regression\JitBlue\GitHub_19397\GitHub_19397\GitHub_19397.cmd
+WorkingDir=JIT\Regression\JitBlue\GitHub_19397\GitHub_19397
+Expected=0
+MaxAllowedDurationSeconds=600
+Categories=EXPECTED_PASS
+HostStyle=0
diff --git a/tests/arm64/Tests.lst b/tests/arm64/Tests.lst
index ffbdf2c642..76012ae386 100644
--- a/tests/arm64/Tests.lst
+++ b/tests/arm64/Tests.lst
@@ -94635,3 +94635,11 @@ Expected=0
 MaxAllowedDurationSeconds=600
 Categories=EXPECTED_PASS
 HostStyle=0
+
+[GitHub_19397.cmd_12235]
+RelativePath=JIT\Regression\JitBlue\GitHub_19397\GitHub_19397\GitHub_19397.cmd
+WorkingDir=JIT\Regression\JitBlue\GitHub_19397\GitHub_19397
+Expected=0
+MaxAllowedDurationSeconds=600
+Categories=EXPECTED_PASS
+HostStyle=0
diff --git a/tests/src/JIT/Regression/JitBlue/GitHub_19397/GitHub_19397.cs b/tests/src/JIT/Regression/JitBlue/GitHub_19397/GitHub_19397.cs
new file mode 100644
index 0000000000..c8ef401489
--- /dev/null
+++ b/tests/src/JIT/Regression/JitBlue/GitHub_19397/GitHub_19397.cs
@@ -0,0 +1,37 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+using System;
+using System.Runtime.CompilerServices;
+
+// This is a regression test for a bug that was exposed with jitStressRegs=8 in
+// System.Text.ConsoleEncoding::GetMaxByteCount, due to the lack of handling
+// of a register-allocator-added COPY of a multi-reg multiply.
+
+namespace GitHub_19397
+{
+    public class Program
+    {
+        [MethodImplAttribute(MethodImplOptions.NoInlining)]
+        public static long getValue()
+        {
+            return(0x0101010101010101L);
+        }
+        static int Main()
+        {
+            long value = getValue();
+            Console.WriteLine($"Result is {value}");
+            if (value == 0x0101010101010101L)
+            {
+                Console.WriteLine("PASS");
+                return 100;
+            }
+            else
+            {
+                Console.WriteLine("FAIL");
+                return -1;
+            }
+        }
+
+    }
+}
diff --git a/tests/src/JIT/Regression/JitBlue/GitHub_19397/GitHub_19397.csproj b/tests/src/JIT/Regression/JitBlue/GitHub_19397/GitHub_19397.csproj
new file mode 100644
index 0000000000..fe27f5370a
--- /dev/null
+++ b/tests/src/JIT/Regression/JitBlue/GitHub_19397/GitHub_19397.csproj
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <AssemblyName>$(MSBuildProjectName)</AssemblyName>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{76E69AA0-8C5A-4F76-8561-B8089FFA8D79}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <ProjectTypeGuids>{786C830F-07A1-408B-BD7F-6EE04809D6DB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
+
+  </PropertyGroup>
+  <!-- Default configurations to help VS understand the configurations -->
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+  </PropertyGroup>
+  <ItemGroup>
+    <CodeAnalysisDependentAssemblyPaths Condition=" '$(VS100COMNTOOLS)' != '' " Include="$(VS100COMNTOOLS)..\IDE\PrivateAssemblies">
+      <Visible>False</Visible>
+    </CodeAnalysisDependentAssemblyPaths>
+  </ItemGroup>
+  <PropertyGroup>
+    <DebugType></DebugType>
+    <Optimize>True</Optimize>
+    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+  <PropertyGroup Condition=" '$(MsBuildProjectDirOverride)' != '' "></PropertyGroup>
+</Project>