diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -278,7 +278,7 @@
   /// Get the FI entries, sorted by fragment offset.
   ArrayRef<FrameIndexExpr> getFrameIndexExprs() const;
   bool hasFrameIndexExprs() const { return holds<MMILoc>(); }
-  void addMMIEntry(const DbgVariable &V);
+  void addMMIEntry(const DIExpression *Expr, int FI);
 
   // Translate tag to proper Dwarf tag.
   dwarf::Tag getTag() const {
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -305,12 +305,8 @@
   return FrameIndexExprs;
 }
 
-void DbgVariable::addMMIEntry(const DbgVariable &V) {
-  assert(V.getVariable() == getVariable() && "conflicting variable");
-  assert(V.getInlinedAt() == getInlinedAt() && "conflicting inlined-at location");
-
+void DbgVariable::addMMIEntry(const DIExpression *Expr, int FI) {
   auto &FrameIndexExprs = get<MMILoc>().FrameIndexExprs;
-  auto &VFrameIndexExprs = V.get<MMILoc>().FrameIndexExprs;
 
   // FIXME: This logic should not be necessary anymore, as we now have proper
   // deduplication. However, without it, we currently run into the assertion
@@ -322,12 +318,10 @@
       return;
   }
 
-  for (const auto &FIE : VFrameIndexExprs)
-    // Ignore duplicate entries.
-    if (llvm::none_of(FrameIndexExprs, [&](const FrameIndexExpr &Other) {
-          return FIE.FI == Other.FI && FIE.Expr == Other.Expr;
-        }))
-      FrameIndexExprs.push_back(FIE);
+  if (llvm::none_of(FrameIndexExprs, [&](const FrameIndexExpr &Other) {
+        return FI == Other.FI && Expr == Other.Expr;
+      }))
+    FrameIndexExprs.push_back({FI, Expr});
 
   assert((FrameIndexExprs.size() == 1 ||
           llvm::all_of(FrameIndexExprs,
@@ -1574,6 +1568,15 @@
     }
 
     ensureAbstractEntityIsCreatedIfScoped(TheCU, Var.first, Scope->getScopeNode());
+
+    if (DbgVariable *DbgVar = MFVars.lookup(Var)) {
+      if (DbgVar->hasFrameIndexExprs())
+        DbgVar->addMMIEntry(VI.Expr, VI.getStackSlot());
+      else
+        DbgVar->addEntryValueExpr(VI.getEntryValueRegister(), *VI.Expr);
+      continue;
+    }
+
     auto RegVar = std::make_unique<DbgVariable>(
                     cast<DILocalVariable>(Var.first), Var.second);
     if (VI.inStackSlot())
@@ -1582,16 +1585,9 @@
       RegVar->initializeEntryValue(VI.getEntryValueRegister(), *VI.Expr);
     LLVM_DEBUG(dbgs() << "Created DbgVariable for " << VI.Var->getName()
                       << "\n");
-
-    if (DbgVariable *DbgVar = MFVars.lookup(Var)) {
-      if (DbgVar->hasFrameIndexExprs())
-        DbgVar->addMMIEntry(*RegVar);
-      else
-        DbgVar->addEntryValueExpr(VI.getEntryValueRegister(), *VI.Expr);
-    } else if (InfoHolder.addScopeVariable(Scope, RegVar.get())) {
-      MFVars.insert({Var, RegVar.get()});
-      ConcreteEntities.push_back(std::move(RegVar));
-    }
+    InfoHolder.addScopeVariable(Scope, RegVar.get());
+    MFVars.insert({Var, RegVar.get()});
+    ConcreteEntities.push_back(std::move(RegVar));
   }
 }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.h
@@ -150,8 +150,7 @@
   MCSymbol *getRnglistsTableBaseSym() const { return RnglistsTableBaseSym; }
   void setRnglistsTableBaseSym(MCSymbol *Sym) { RnglistsTableBaseSym = Sym; }
 
-  /// \returns false if the variable was merged with a previous one.
-  bool addScopeVariable(LexicalScope *LS, DbgVariable *Var);
+  void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
 
   void addScopeLabel(LexicalScope *LS, DbgLabel *Label);
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
@@ -102,21 +102,15 @@
   StrPool.emit(*Asm, StrSection, OffsetSection, UseRelativeOffsets);
 }
 
-bool DwarfFile::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
+void DwarfFile::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
   auto &ScopeVars = ScopeVariables[LS];
   const DILocalVariable *DV = Var->getVariable();
   if (unsigned ArgNum = DV->getArg()) {
-    auto Cached = ScopeVars.Args.find(ArgNum);
-    if (Cached == ScopeVars.Args.end())
-      ScopeVars.Args[ArgNum] = Var;
-    else {
-      Cached->second->addMMIEntry(*Var);
-      return false;
-    }
+    auto Ret = ScopeVars.Args.insert({ArgNum, Var});
+    assert(Ret.second);
   } else {
     ScopeVars.Locals.push_back(Var);
   }
-  return true;
 }
 
 void DwarfFile::addScopeLabel(LexicalScope *LS, DbgLabel *Label) {