Fixing some issues with the Int128 interop test for non-Windows

src/libraries/System.Private.CoreLib/src/System/Int128.cs

@@ -23,8 +23,8 @@ public readonly struct Int128
         // Unix System V ABI actually requires this to be little endian
         // order and not `upper, lower` on big endian systems.
 
-        private readonly ulong _upper;
         private readonly ulong _lower;
+        private readonly ulong _upper;
 
         /// <summary>Initializes a new instance of the <see cref="Int128" /> struct.</summary>
         /// <param name="upper">The upper 64-bits of the 128-bit value.</param>

src/tests/Interop/PInvoke/Int128/Int128Native.cpp

@@ -23,8 +23,14 @@ extern "C" DLL_EXPORT Int128 STDMETHODCALLTYPE GetInt128(uint64_t upper, uint64_
 {
     Int128 result;
 
+#if (INT128_WIDTH == 128) || defined(__SIZEOF_INT128__)
+    result = upper;
+    result = result << 64;
+    result = result | lower;
+#else
     result.lower = lower;
     result.upper = upper;
+#endif
 
     return result;
 }
@@ -45,10 +51,14 @@ extern "C" DLL_EXPORT Int128 STDMETHODCALLTYPE AddInt128(Int128 lhs, Int128 rhs)
 {
     Int128 result;
 
+#if (INT128_WIDTH == 128) || defined(__SIZEOF_INT128__)
+    result = lhs + rhs;
+#else
     result.lower = lhs.lower + rhs.lower;
     uint64_t carry = (result.lower < lhs.lower) ? 1 : 0;
-
     result.upper = lhs.upper + rhs.upper + carry;
+#endif
+
     return result;
 }
 

src/tests/Interop/PInvoke/Int128/Int128Test.csproj

@@ -2,6 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <DebugType>embedded</DebugType>
     <OutputType>exe</OutputType>
   </PropertyGroup>
   <ItemGroup>

src/tests/Interop/PInvoke/Int128/UInt128Native.cpp

@@ -23,8 +23,14 @@ extern "C" DLL_EXPORT UInt128 STDMETHODCALLTYPE GetUInt128(uint64_t upper, uint6
 {
     UInt128 result;
 
+#if (INT128_WIDTH == 128) || defined(__SIZEOF_INT128__)
+    result = upper;
+    result = result << 64;
+    result = result | lower;
+#else
     result.lower = lower;
     result.upper = upper;
+#endif
 
     return result;
 }
@@ -45,10 +51,14 @@ extern "C" DLL_EXPORT UInt128 STDMETHODCALLTYPE AddUInt128(UInt128 lhs, UInt128
 {
     UInt128 result;
 
+#if (UINT128_WIDTH == 128) || defined(__SIZEOF_INT128__)
+    result = lhs + rhs;
+#else
     result.lower = lhs.lower + rhs.lower;
     uint64_t carry = (result.lower < lhs.lower) ? 1 : 0;
-
     result.upper = lhs.upper + rhs.upper + carry;
+#endif
+
     return result;
 }
 

src/tests/issues.targets

@@ -3308,6 +3308,9 @@
         <ExcludeList Include = "$(XunitTestBinBase)/Interop/ICustomMarshaler/ConflictingNames/SameNameDifferentAssembly/**">
             <Issue>https://github.com/dotnet/runtime/issues/41519</Issue>
         </ExcludeList>
+        <ExcludeList Include = "$(XunitTestBinBase)/Interop/PInvoke/Int128/**">
+            <Issue>https://github.com/dotnet/runtime/issues/41519</Issue>
+        </ExcludeList>
         <ExcludeList Include = "$(XunitTestBinBase)/Interop/PInvoke/Miscellaneous/HandleRef/HandleRefTest/**">
             <Issue>https://github.com/dotnet/runtime/issues/41519</Issue>
         </ExcludeList>