Handle mis-sized structs in ARM/64 PUTARG_STK codegen (#69905)

* Handle mis-sized structs for PUTARG_STK on ARM/64

We will now generate a series of small loads as necessary
to handle "remainderSize"s of 3, 5, 6 and 7.

* Add tests

* Re-enable tests for 60705

src/coreclr/jit/codegenarmarch.cpp

@@ -1095,8 +1095,9 @@ void CodeGen::genPutArgStk(GenTreePutArgStk* treeNode)
 
             while (remainingSize > 0)
             {
-                var_types type;
+                nextIndex = structOffset / TARGET_POINTER_SIZE;
 
+                var_types type;
                 if (remainingSize >= TARGET_POINTER_SIZE)
                 {
                     type = layout->GetGCPtrType(nextIndex);
@@ -1106,18 +1107,18 @@ void CodeGen::genPutArgStk(GenTreePutArgStk* treeNode)
                     // the left over size is smaller than a pointer and thus can never be a GC type
                     assert(!layout->IsGCPtr(nextIndex));
 
-                    if (remainingSize == 1)
+                    if (remainingSize >= 4)
                     {
-                        type = TYP_UBYTE;
+                        type = TYP_INT;
                     }
-                    else if (remainingSize == 2)
+                    else if (remainingSize >= 2)
                     {
                         type = TYP_USHORT;
                     }
                     else
                     {
-                        assert(remainingSize == 4);
-                        type = TYP_UINT;
+                        assert(remainingSize == 1);
+                        type = TYP_UBYTE;
                     }
                 }
 
@@ -1146,7 +1147,6 @@ void CodeGen::genPutArgStk(GenTreePutArgStk* treeNode)
                 assert(argOffsetOut <= argOffsetMax); // We can't write beyond the outgoing arg area
 
                 structOffset += moveSize;
-                nextIndex++;
             }
         }
     }

src/libraries/tests.proj

@@ -99,11 +99,6 @@
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.InteropServices\tests\LibraryImportGenerator.Tests\LibraryImportGenerator.Tests.csproj" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetArchitecture)' == 'arm'">
-    <!-- Issue: https://github.com/dotnet/runtime/issues/60705 -->
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.InteropServices\tests\LibraryImportGenerator.UnitTests\LibraryImportGenerator.Unit.Tests.csproj" />
-  </ItemGroup>
-
   <ItemGroup Condition="'$(TargetOS)' == 'FreeBSD'">
     <!-- LibraryImportGenerator runtime tests build depends pulling down a pre-built nethost binary, which is not available for FreeBSD. -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.InteropServices\tests\LibraryImportGenerator.Tests\LibraryImportGenerator.Tests.csproj" />

src/tests/JIT/Directed/StructABI/MisSizedStructs.cs

@@ -0,0 +1,196 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.InteropServices;
+using System.Runtime.CompilerServices;
+
+public unsafe class MisSizedStructs
+{
+    public const byte ByteValue = 0xC1;
+
+    public static int Main()
+    {
+        const int BytesSize = 256;
+        var bytes = stackalloc byte[BytesSize];
+        Unsafe.InitBlock(bytes, ByteValue, BytesSize);
+
+        if (ProblemWithStructWithThreeBytes(bytes))
+        {
+            return 101;
+        }
+
+        if (ProblemWithStructWithFiveBytes(bytes))
+        {
+            return 102;
+        }
+
+        if (ProblemWithStructWithSixBytes(bytes))
+        {
+            return 103;
+        }
+
+        if (ProblemWithStructWithSevenBytes(bytes))
+        {
+            return 104;
+        }
+
+        if (ProblemWithStructWithElevenBytes(bytes))
+        {
+            return 105;
+        }
+
+        if (ProblemWithStructWithThirteenBytes(bytes))
+        {
+            return 106;
+        }
+
+        if (ProblemWithStructWithFourteenBytes(bytes))
+        {
+            return 107;
+        }
+
+        if (ProblemWithStructWithFifteenBytes(bytes))
+        {
+            return 108;
+        }
+
+        if (ProblemWithStructWithNineteenBytes(bytes))
+        {
+            return 109;
+        }
+
+        return 100;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithThreeBytes(byte* bytes)
+    {
+        return CallForStructWithThreeBytes(default, *(StructWithThreeBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithFiveBytes(byte* bytes)
+    {
+        return CallForStructWithFiveBytes(default, *(StructWithFiveBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithSixBytes(byte* bytes)
+    {
+        return CallForStructWithSixBytes(default, *(StructWithSixBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithSevenBytes(byte* bytes)
+    {
+        return CallForStructWithSevenBytes(default, *(StructWithSevenBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithElevenBytes(byte* bytes)
+    {
+        return CallForStructWithElevenBytes(default, *(StructWithElevenBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithThirteenBytes(byte* bytes)
+    {
+        return CallForStructWithThirteenBytes(default, *(StructWithThirteenBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithFourteenBytes(byte* bytes)
+    {
+        return CallForStructWithFourteenBytes(default, *(StructWithFourteenBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithFifteenBytes(byte* bytes)
+    {
+        return CallForStructWithFifteenBytes(default, *(StructWithFifteenBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static bool ProblemWithStructWithNineteenBytes(byte* bytes)
+    {
+        return CallForStructWithNineteenBytes(default, *(StructWithNineteenBytes*)bytes) != ByteValue;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithThreeBytes(ForceStackUsage fs, StructWithThreeBytes value) => value.Bytes[2];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithFiveBytes(ForceStackUsage fs, StructWithFiveBytes value) => value.Bytes[4];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithSixBytes(ForceStackUsage fs, StructWithSixBytes value) => value.Bytes[5];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithSevenBytes(ForceStackUsage fs, StructWithSevenBytes value) => value.Bytes[6];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithElevenBytes(ForceStackUsage fs, StructWithElevenBytes value) => value.Bytes[10];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithThirteenBytes(ForceStackUsage fs, StructWithThirteenBytes value) => value.Bytes[12];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithFourteenBytes(ForceStackUsage fs, StructWithFourteenBytes value) => value.Bytes[13];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithFifteenBytes(ForceStackUsage fs, StructWithFifteenBytes value) => value.Bytes[14];
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static byte CallForStructWithNineteenBytes(ForceStackUsage fs, StructWithNineteenBytes value) => value.Bytes[18];
+
+    struct ForceStackUsage
+    {
+        public fixed byte Bytes[40];
+    }
+
+    struct StructWithThreeBytes
+    {
+        public fixed byte Bytes[3];
+    }
+
+    struct StructWithFiveBytes
+    {
+        public fixed byte Bytes[5];
+    }
+
+    struct StructWithSixBytes
+    {
+        public fixed byte Bytes[6];
+    }
+
+    struct StructWithSevenBytes
+    {
+        public fixed byte Bytes[7];
+    }
+
+    struct StructWithElevenBytes
+    {
+        public fixed byte Bytes[11];
+    }
+
+    struct StructWithThirteenBytes
+    {
+        public fixed byte Bytes[13];
+    }
+
+    struct StructWithFourteenBytes
+    {
+        public fixed byte Bytes[14];
+    }
+
+    struct StructWithFifteenBytes
+    {
+        public fixed byte Bytes[15];
+    }
+
+    struct StructWithNineteenBytes
+    {
+        public fixed byte Bytes[19];
+    }
+}

src/tests/JIT/Directed/StructABI/MisSizedStructs.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+  <PropertyGroup>
+    <DebugType>PdbOnly</DebugType>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>