From 096856d7ad54d28d05212fb320694624df24f89c Mon Sep 17 00:00:00 2001
From: Egor Chesakov <Egor.Chesakov@microsoft.com>
Date: Fri, 3 Dec 2021 16:51:01 -0800
Subject: [PATCH 1/3] Add regression test for
 https://github.com/dotnet/runtime/issues/62249

---
 .../JitBlue/Runtime_62249/Runtime_62249.cs    | 39 +++++++++++++++++++
 .../Runtime_62249/Runtime_62249.csproj        |  9 +++++
 2 files changed, 48 insertions(+)
 create mode 100644 src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.cs
 create mode 100644 src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.csproj

diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.cs b/src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.cs
new file mode 100644
index 00000000000000..2bdaf33de4dbfc
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.cs
@@ -0,0 +1,39 @@
+// 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.CompilerServices;
+
+class Runtime_62249
+{
+    public struct CanBeReinterpretedAsDouble
+    {
+        public double _0;
+    }
+
+    // Note that all VFP registers are occupied by d0-d7 arguments, hence the last argument is passed on the stack.
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    public static int Callee(double d0, double d1, double d2, double d3, double d4, double d5, double d6, double d7, CanBeReinterpretedAsDouble onStack)
+    {
+        return onStack._0 == 62249 ? 100 : 0;
+    }
+
+    public static int Caller(ref CanBeReinterpretedAsDouble byRef)
+    {
+        // Since the last parameter
+        //   1. Is passed by value
+        //   2. Has size of power of 2
+        //   3. Has a single field
+        // morph transforms OBJ(struct<CanBeReinterpretedAsDouble, 8>, byRef) to IND(double, byRef).
+        // However, lower does not expect such transformation and asserts.
+        return Callee(0, 0, 0, 6, 2, 2, 4, 9, byRef);
+    }
+
+    public static int Main(string[] args)
+    {
+        var val = new CanBeReinterpretedAsDouble();
+        val._0 = 62249;
+
+        return Caller(ref val);
+    }
+}
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.csproj b/src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.csproj
new file mode 100644
index 00000000000000..6946bed81bfd5b
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_62249/Runtime_62249.csproj
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>

From a990e05040004a5a0d71e215960a5da11d3b278d Mon Sep 17 00:00:00 2001
From: Egor Chesakov <Egor.Chesakov@microsoft.com>
Date: Fri, 3 Dec 2021 16:53:39 -0800
Subject: [PATCH 2/3] On Arm32 FEATURE_SIMD is not supported, hence
 varTypeIsSIMD() always returns false. Change the assert, so it checks that
 the argument type is TYP_DOUBLE in Lowering::NewPutArg() in
 src/coreclr/jit/lower.cpp

---
 src/coreclr/jit/lower.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/coreclr/jit/lower.cpp b/src/coreclr/jit/lower.cpp
index 1c9febeb131440..992f8b98a8faff 100644
--- a/src/coreclr/jit/lower.cpp
+++ b/src/coreclr/jit/lower.cpp
@@ -1257,7 +1257,12 @@ GenTree* Lowering::NewPutArg(GenTreeCall* call, GenTree* arg, fgArgTabEntry* inf
                 }
                 else if (!arg->OperIs(GT_FIELD_LIST))
                 {
+#ifdef TARGET_ARM
+                    assert((info->GetStackSlotsNumber() == 1) ||
+                           (arg->TypeGet() == TYP_DOUBLE) && (info->GetStackSlotsNumber() == 2));
+#else
                     assert(varTypeIsSIMD(arg) || (info->GetStackSlotsNumber() == 1));
+#endif
                 }
             }
 #endif // FEATURE_PUT_STRUCT_ARG_STK

From d7ecdd420549b0f318bc7d16efcd5056d96c11b0 Mon Sep 17 00:00:00 2001
From: Egor Chesakov <Egor.Chesakov@microsoft.com>
Date: Fri, 3 Dec 2021 18:03:08 -0800
Subject: [PATCH 3/3] Fix GCC error

---
 src/coreclr/jit/lower.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/coreclr/jit/lower.cpp b/src/coreclr/jit/lower.cpp
index 992f8b98a8faff..2467a00accdaa7 100644
--- a/src/coreclr/jit/lower.cpp
+++ b/src/coreclr/jit/lower.cpp
@@ -1259,7 +1259,7 @@ GenTree* Lowering::NewPutArg(GenTreeCall* call, GenTree* arg, fgArgTabEntry* inf
                 {
 #ifdef TARGET_ARM
                     assert((info->GetStackSlotsNumber() == 1) ||
-                           (arg->TypeGet() == TYP_DOUBLE) && (info->GetStackSlotsNumber() == 2));
+                           ((arg->TypeGet() == TYP_DOUBLE) && (info->GetStackSlotsNumber() == 2)));
 #else
                     assert(varTypeIsSIMD(arg) || (info->GetStackSlotsNumber() == 1));
 #endif