From 0613e9cbfd66daf98432076c5b9ac164308d3e4a Mon Sep 17 00:00:00 2001
From: Jakob Botsch Nielsen <jakob.botsch.nielsen@gmail.com>
Date: Sun, 6 Feb 2022 20:37:47 +0100
Subject: [PATCH] Normalize returns after optimizing returned indirs

This ensures we normalize returned indirs of locals, even when we fold
it into an access of a promoted local's field. This may change a signed
indir into access of an unsigned field, which may need a sign-extending
cast to be inserted.

It is not ideal that fgMorphRetInd can 'lose' this information, but
given that it is a specialized optimization it seems the simplest
solution is to just rely on the follow-up normalization.

Fix #61359
---
 src/coreclr/jit/morph.cpp                     | 35 ++++++++++---------
 .../JitBlue/Runtime_61359/Runtime_61359.cs    | 19 ++++++++++
 .../Runtime_61359/Runtime_61359.csproj        | 13 +++++++
 3 files changed, 50 insertions(+), 17 deletions(-)
 create mode 100644 src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.cs
 create mode 100644 src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.csproj

diff --git a/src/coreclr/jit/morph.cpp b/src/coreclr/jit/morph.cpp
index 27300cd32d63b7..bfacb1624e2441 100644
--- a/src/coreclr/jit/morph.cpp
+++ b/src/coreclr/jit/morph.cpp
@@ -11421,23 +11421,6 @@ GenTree* Compiler::fgMorphSmpOp(GenTree* tree, MorphAddrContext* mac)
             return fgMorphIntoHelperCall(tree, helper, gtNewCallArgs(op1, op2));
 
         case GT_RETURN:
-            // normalize small integer return values
-            if (fgGlobalMorph && varTypeIsSmall(info.compRetType) && (op1 != nullptr) && !op1->TypeIs(TYP_VOID) &&
-                fgCastNeeded(op1, info.compRetType))
-            {
-                // Small-typed return values are normalized by the callee
-                op1 = gtNewCastNode(TYP_INT, op1, false, info.compRetType);
-
-                // Propagate GTF_COLON_COND
-                op1->gtFlags |= (tree->gtFlags & GTF_COLON_COND);
-
-                tree->AsOp()->gtOp1 = fgMorphTree(op1);
-
-                // Propagate side effect flags
-                tree->SetAllEffectsFlags(tree->AsOp()->gtGetOp1());
-
-                return tree;
-            }
             if (!tree->TypeIs(TYP_VOID))
             {
                 if (op1->OperIs(GT_OBJ, GT_BLK, GT_IND))
@@ -11471,6 +11454,24 @@ GenTree* Compiler::fgMorphSmpOp(GenTree* tree, MorphAddrContext* mac)
                     }
                 }
             }
+
+            // normalize small integer return values
+            if (fgGlobalMorph && varTypeIsSmall(info.compRetType) && (op1 != nullptr) && !op1->TypeIs(TYP_VOID) &&
+                fgCastNeeded(op1, info.compRetType))
+            {
+                // Small-typed return values are normalized by the callee
+                op1 = gtNewCastNode(TYP_INT, op1, false, info.compRetType);
+
+                // Propagate GTF_COLON_COND
+                op1->gtFlags |= (tree->gtFlags & GTF_COLON_COND);
+
+                tree->AsOp()->gtOp1 = fgMorphTree(op1);
+
+                // Propagate side effect flags
+                tree->SetAllEffectsFlags(tree->AsOp()->gtGetOp1());
+
+                return tree;
+            }
             break;
 
         case GT_EQ:
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.cs b/src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.cs
new file mode 100644
index 00000000000000..6a38a4cf157de6
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.cs
@@ -0,0 +1,19 @@
+// 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;
+
+public unsafe class Runtime_61359
+{
+    public static int Main()
+    {
+        return HalfToInt16Bits((Half)(-1)) == -17408 ? 100 : -1;
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    static short HalfToInt16Bits(Half h)
+    {
+        return *(short*)&h;
+    }
+}  
\ No newline at end of file
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.csproj b/src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.csproj
new file mode 100644
index 00000000000000..1a1d3eadae5ce4
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_61359/Runtime_61359.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+  </PropertyGroup>
+  <PropertyGroup>
+    <DebugType>None</DebugType>
+    <Optimize>True</Optimize>
+    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>
\ No newline at end of file