From 16390d8d46532b6dcc7d047307ede89d24284a3b Mon Sep 17 00:00:00 2001
From: EgorBo <egorbo@gmail.com>
Date: Fri, 19 Jul 2024 16:34:29 +0200
Subject: [PATCH] don't narrow cast(ind(x))

---
 src/coreclr/jit/optimizer.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/coreclr/jit/optimizer.cpp b/src/coreclr/jit/optimizer.cpp
index 8fb5ca0493566..614340acab3b7 100644
--- a/src/coreclr/jit/optimizer.cpp
+++ b/src/coreclr/jit/optimizer.cpp
@@ -3518,6 +3518,13 @@ bool Compiler::optNarrowTree(GenTree* tree, var_types srct, var_types dstt, Valu
 
             case GT_IND:
 
+                if (opts.OptimizationEnabled())
+                {
+                    // Don't narrow casts of indirections when optimizations are enabled
+                    // to enable more CSEs.
+                    return false;
+                }
+
             NARROW_IND:
 
                 if ((dstSize > genTypeSize(tree->gtType)) &&