From 9158543338acd47019ffb6ec634a273a9e28cb99 Mon Sep 17 00:00:00 2001
From: SingleAccretion <62474226+SingleAccretion@users.noreply.github.com>
Date: Wed, 11 May 2022 12:40:50 +0300
Subject: [PATCH] Copy propagate on `LCL_FLD`s (#68592)

---
 src/coreclr/jit/copyprop.cpp | 20 +++++++++++---------
 src/coreclr/jit/gentree.cpp  |  2 +-
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/coreclr/jit/copyprop.cpp b/src/coreclr/jit/copyprop.cpp
index 0ec7ae088233a..778dd7d404f6e 100644
--- a/src/coreclr/jit/copyprop.cpp
+++ b/src/coreclr/jit/copyprop.cpp
@@ -205,15 +205,18 @@ void Compiler::optCopyProp(Statement* stmt, GenTreeLclVarCommon* tree, unsigned
             continue;
         }
 
-        var_types newLclType = newLclVarDsc->TypeGet();
-        if (!newLclVarDsc->lvNormalizeOnLoad())
+        if (tree->OperIs(GT_LCL_VAR))
         {
-            newLclType = genActualType(newLclType);
-        }
+            var_types newLclType = newLclVarDsc->TypeGet();
+            if (!newLclVarDsc->lvNormalizeOnLoad())
+            {
+                newLclType = genActualType(newLclType);
+            }
 
-        if (newLclType != tree->TypeGet())
-        {
-            continue;
+            if (newLclType != tree->TypeGet())
+            {
+                continue;
+            }
         }
 
 #ifdef DEBUG
@@ -388,8 +391,7 @@ void Compiler::optBlockCopyProp(BasicBlock* block, LclNumToLiveDefsMap* curSsaNa
 
                 optCopyPropPushDef(tree, lclDefNode, lclNum, curSsaName);
             }
-            // TODO-CQ: propagate on LCL_FLDs too.
-            else if (tree->OperIs(GT_LCL_VAR) && ((tree->gtFlags & GTF_VAR_DEF) == 0))
+            else if (tree->OperIs(GT_LCL_VAR, GT_LCL_FLD) && ((tree->gtFlags & GTF_VAR_DEF) == 0))
             {
                 const unsigned lclNum = optIsSsaLocal(tree->AsLclVarCommon());
 
diff --git a/src/coreclr/jit/gentree.cpp b/src/coreclr/jit/gentree.cpp
index 3574d3c258698..bf1cd117fe872 100644
--- a/src/coreclr/jit/gentree.cpp
+++ b/src/coreclr/jit/gentree.cpp
@@ -8136,7 +8136,7 @@ GenTree* Compiler::gtCloneExpr(
                         new (this, GT_LCL_FLD) GenTreeLclFld(GT_LCL_FLD, tree->TypeGet(), tree->AsLclFld()->GetLclNum(),
                                                              tree->AsLclFld()->GetLclOffs());
                     copy->AsLclFld()->SetFieldSeq(tree->AsLclFld()->GetFieldSeq());
-                    copy->gtFlags = tree->gtFlags;
+                    copy->AsLclFld()->SetSsaNum(tree->AsLclFld()->GetSsaNum());
                 }
                 goto DONE;