Extend redundant zero init optimization to recognize assignments to `…

…GT_OBJ(lcl_addr)` and `GT_BLK(lcl_addr)` Fixes #38070.
dotnet · Jun 24, 2020 · 9d35b6d · 9d35b6d
1 parent 69fca92
commit 9d35b6d
Showing 1 changed file with 18 additions and 2 deletions.
diff --git a/src/coreclr/src/jit/optimizer.cpp b/src/coreclr/src/jit/optimizer.cpp
@@ -9279,12 +9279,28 @@ void Compiler::optRemoveRedundantZeroInits()
                     case GT_ASG:
                     {
                         GenTreeOp* treeOp = tree->AsOp();
-                        if (!treeOp->gtOp1->OperIs(GT_LCL_VAR, GT_LCL_FLD))
+
+                        unsigned lclNum = BAD_VAR_NUM;
+
+                        if (treeOp->gtOp1->OperIs(GT_LCL_VAR, GT_LCL_FLD))
+                        {
+                            lclNum = treeOp->gtOp1->AsLclVarCommon()->GetLclNum();
+                        }
+                        else if (treeOp->gtOp1->OperIs(GT_OBJ, GT_BLK))
+                        {
+                            GenTreeLclVarCommon* lcl = treeOp->gtOp1->gtGetOp1()->IsLocalAddrExpr();
+
+                            if (lcl != nullptr)
+                            {
+                                lclNum = lcl->GetLclNum();
+                            }
+                        }
+
+                        if (lclNum == BAD_VAR_NUM)
                         {
                             break;
                         }
 
-                        unsigned         lclNum    = treeOp->gtOp1->AsLclVarCommon()->GetLclNum();
                         LclVarDsc* const lclDsc    = lvaGetDesc(lclNum);
                         unsigned*        pRefCount = refCounts.LookupPointer(lclNum);