From 0cbf06541ac0c95056337a79029559194bfea722 Mon Sep 17 00:00:00 2001
From: Jakob Botsch Nielsen <jakob.botsch.nielsen@gmail.com>
Date: Fri, 16 Dec 2022 13:09:54 +0100
Subject: [PATCH] JIT: Fix switch peeling flags propagation

Otherwise we could propagate overlapping flags that change meaning.
Extracted from early liveness PR.
---
 src/coreclr/jit/fgopt.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/coreclr/jit/fgopt.cpp b/src/coreclr/jit/fgopt.cpp
index 50bc965a68d0d2..16eb52cf3823e3 100644
--- a/src/coreclr/jit/fgopt.cpp
+++ b/src/coreclr/jit/fgopt.cpp
@@ -4321,9 +4321,9 @@ bool Compiler::fgOptimizeSwitchJumps()
 
         // Update flags
         //
-        switchTree->gtFlags = switchTree->AsOp()->gtOp1->gtFlags;
-        dominantCaseCompare->gtFlags |= dominantCaseCompare->AsOp()->gtOp1->gtFlags;
-        jmpTree->gtFlags |= dominantCaseCompare->gtFlags;
+        switchTree->gtFlags = switchTree->AsOp()->gtOp1->gtFlags & GTF_ALL_EFFECT;
+        dominantCaseCompare->gtFlags |= dominantCaseCompare->AsOp()->gtOp1->gtFlags & GTF_ALL_EFFECT;
+        jmpTree->gtFlags |= dominantCaseCompare->gtFlags & GTF_ALL_EFFECT;
         dominantCaseCompare->gtFlags |= GTF_RELOP_JMP_USED | GTF_DONT_CSE;
 
         // Wire up the new control flow.