diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -1987,7 +1987,11 @@
       if (SkipStores.contains(Def) || MSSA.isLiveOnEntryDef(Def) ||
           !isRemovable(Def->getMemoryInst()))
         continue;
-      auto *UpperDef = dyn_cast<MemoryDef>(Def->getDefiningAccess());
+      MemoryDef *UpperDef;
+      if (Def->isOptimized())
+        UpperDef = dyn_cast<MemoryDef>(Def->getOptimized());
+      else
+        UpperDef = dyn_cast<MemoryDef>(Def->getDefiningAccess());
       if (!UpperDef || MSSA.isLiveOnEntryDef(UpperDef))
         continue;
 
diff --git a/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll b/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll
--- a/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/stores-of-existing-values.ll
@@ -324,7 +324,6 @@
 ; CHECK:       bb2:
 ; CHECK-NEXT:    ret void
 ; CHECK:       bb3:
-; CHECK-NEXT:    store i32 0, i32* [[P]], align 4
 ; CHECK-NEXT:    ret void
 ;
   store i32 0, i32* %P
@@ -416,8 +415,6 @@
 ; CHECK-NEXT:    call void @llvm.memset.p0i8.i64(i8* [[PTR:%.*]], i8 0, i64 10, i1 false)
 ; CHECK-NEXT:    [[PTR_4:%.*]] = getelementptr i8, i8* [[PTR]], i64 4
 ; CHECK-NEXT:    store i8 8, i8* [[PTR_4]], align 1
-; CHECK-NEXT:    [[PTR_5:%.*]] = getelementptr i8, i8* [[PTR]], i64 5
-; CHECK-NEXT:    store i8 0, i8* [[PTR_5]], align 1
 ; CHECK-NEXT:    ret void
 ;
   call void @llvm.memset.p0i8.i64(i8* %ptr, i8 0, i64 10, i1 false)
@@ -506,8 +503,8 @@
 
 define void @test14_strcat(i8* noalias %P, i8* noalias %Q) {
 ; CHECK-LABEL: @test14_strcat(
-; CHECK-NEXT:    call i8* @strcat(i8* [[P:%.*]], i8* [[Q:%.*]])
-; CHECK-NEXT:    call i8* @strcat(i8* [[P]], i8* [[Q]])
+; CHECK-NEXT:    [[CALL1:%.*]] = call i8* @strcat(i8* [[P:%.*]], i8* [[Q:%.*]])
+; CHECK-NEXT:    [[CALL2:%.*]] = call i8* @strcat(i8* [[P]], i8* [[Q]])
 ; CHECK-NEXT:    ret void
 ;
   %call1 = call i8* @strcat(i8* %P, i8* %Q)