Adjust impNormStructVal to not wrap in GT_OBJ (#81636)

* Adjust impNormStructVal to not wrap in GT_OBJ * Ensure UpdateEarlyRefCount handles CALL(LCL_VAR)
dotnet · Feb 6, 2023 · 58719ec · 58719ec
1 parent 211cb69
commit 58719ec
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Showing 2 changed files with 29 additions and 38 deletions.
diff --git a/src/coreclr/jit/importer.cpp b/src/coreclr/jit/importer.cpp
@@ -1332,11 +1332,6 @@ GenTree* Compiler::impNormStructVal(GenTree* structVal, CORINFO_CLASS_HANDLE str
 
         case GT_LCL_VAR:
         case GT_LCL_FLD:
-            structLcl = structVal->AsLclVarCommon();
-            // Wrap it in a GT_OBJ.
-            structVal = gtNewObjNode(structHnd, gtNewOperNode(GT_ADDR, TYP_BYREF, structVal));
-            FALLTHROUGH;
-
         case GT_IND:
         case GT_OBJ:
         case GT_BLK:
@@ -1414,12 +1409,6 @@ GenTree* Compiler::impNormStructVal(GenTree* structVal, CORINFO_CLASS_HANDLE str
 
         structLcl = gtNewLclvNode(tmpNum, structType)->AsLclVarCommon();
         structVal = structLcl;
-
-        if (structType == TYP_STRUCT)
-        {
-            // Wrap it in a GT_OBJ
-            structVal = gtNewObjNode(structHnd, gtNewOperNode(GT_ADDR, TYP_BYREF, structVal));
-        }
     }
 
     if (structLcl != nullptr)

diff --git a/src/coreclr/jit/lclmorph.cpp b/src/coreclr/jit/lclmorph.cpp
@@ -1565,40 +1565,42 @@ class LocalAddressVisitor final : public GenTreeVisitor<LocalAddressVisitor>
         // handled in fgCanFastTailCall and fgMakeOutgoingStructArgCopy.
         //
         // CALL(OBJ(LCL_VAR_ADDR...))
-        bool isArgToCall   = false;
-        bool keepSearching = true;
-        for (int i = 0; i < m_ancestors.Height() && keepSearching; i++)
+        // -or-
+        // CALL(LCL_VAR)
+
+        // TODO-1stClassStructs: We've removed most, but not all, cases where OBJ(LCL_VAR_ADDR)
+        // is introduced (it was primarily from impNormStructVal). But until all cases are gone
+        // we still want to handle it as well.
+
+        if (m_ancestors.Height() < 2)
+        {
+            return;
+        }
+
+        GenTree* node = m_ancestors.Top(0);
+
+        if (node->OperIs(GT_LCL_VAR))
         {
-            GenTree* node = m_ancestors.Top(i);
-            switch (i)
+            node = m_ancestors.Top(1);
+        }
+        else if (node->OperIs(GT_LCL_VAR_ADDR))
+        {
+            if (m_ancestors.Height() < 3)
             {
-                case 0:
-                {
-                    keepSearching = node->OperIs(GT_LCL_VAR_ADDR);
-                }
-                break;
+                return;
+            }
 
-                case 1:
-                {
-                    keepSearching = node->OperIs(GT_OBJ);
-                }
-                break;
+            node = m_ancestors.Top(1);
 
-                case 2:
-                {
-                    keepSearching = false;
-                    isArgToCall   = node->IsCall();
-                }
-                break;
-                default:
-                {
-                    keepSearching = false;
-                }
-                break;
+            if (!node->OperIs(GT_OBJ))
+            {
+                return;
             }
+
+            node = m_ancestors.Top(2);
         }
 
-        if (isArgToCall)
+        if (node->IsCall())
         {
             JITDUMP("LocalAddressVisitor incrementing weighted ref count from " FMT_WT " to " FMT_WT
                     " for implicit by-ref V%02d arg passed to call\n",