diff --git a/llvm/include/llvm/CodeGen/DwarfStringPoolEntry.h b/llvm/include/llvm/CodeGen/DwarfStringPoolEntry.h
--- a/llvm/include/llvm/CodeGen/DwarfStringPoolEntry.h
+++ b/llvm/include/llvm/CodeGen/DwarfStringPoolEntry.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_CODEGEN_DWARFSTRINGPOOLENTRY_H
 #define LLVM_CODEGEN_DWARFSTRINGPOOLENTRY_H
 
-#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/StringMap.h"
 
 namespace llvm {
@@ -20,49 +20,76 @@
 struct DwarfStringPoolEntry {
   static constexpr unsigned NotIndexed = -1;
 
-  MCSymbol *Symbol;
-  uint64_t Offset;
-  unsigned Index;
+  MCSymbol *Symbol = nullptr;
+  uint64_t Offset = 0;
+  unsigned Index = 0;
 
   bool isIndexed() const { return Index != NotIndexed; }
 };
 
 /// String pool entry reference.
 class DwarfStringPoolEntryRef {
-  PointerIntPair<const StringMapEntry<DwarfStringPoolEntry> *, 1, bool>
-      MapEntryAndIndexed;
+  /// Full DwarfStringPoolEntry stored in the StringMapEntry.
+  using StringEntryPtr = const StringMapEntry<DwarfStringPoolEntry> *;
 
-  const StringMapEntry<DwarfStringPoolEntry> *getMapEntry() const {
-    return MapEntryAndIndexed.getPointer();
-  }
+  /// Pointer to DwarfStringPoolEntry stored in the StringMapEntry.
+  using ShortStringEntryPtr = const StringMapEntry<DwarfStringPoolEntry *> *;
+
+  /// Pointer to the string pool Entry.
+  PointerUnion<StringEntryPtr, ShortStringEntryPtr> MapEntry = nullptr;
 
 public:
   DwarfStringPoolEntryRef() = default;
-  DwarfStringPoolEntryRef(const StringMapEntry<DwarfStringPoolEntry> &Entry,
-                          bool Indexed)
-      : MapEntryAndIndexed(&Entry, Indexed) {}
 
-  explicit operator bool() const { return getMapEntry(); }
+  // ASSUMPTION: \p Entry mustn`t be reallocated.
+  DwarfStringPoolEntryRef(const StringMapEntry<DwarfStringPoolEntry> &Entry)
+      : MapEntry(&Entry) {}
+
+  // ASSUMPTION: \p Entry mustn`t be reallocated.
+  DwarfStringPoolEntryRef(const StringMapEntry<DwarfStringPoolEntry *> &Entry)
+      : MapEntry(&Entry) {}
+
+  explicit operator bool() const { return !MapEntry.isNull(); }
+
+  /// \returns symbol for the dwarf string.
   MCSymbol *getSymbol() const {
-    assert(getMapEntry()->second.Symbol && "No symbol available!");
-    return getMapEntry()->second.Symbol;
+    assert(getEntry().Symbol && "No symbol available!");
+    return getEntry().Symbol;
   }
-  uint64_t getOffset() const { return getMapEntry()->second.Offset; }
-  bool isIndexed() const { return MapEntryAndIndexed.getInt(); }
+
+  /// \returns offset for the dwarf string.
+  uint64_t getOffset() const { return getEntry().Offset; }
+
+  /// \returns index for the dwarf string.
   unsigned getIndex() const {
-    assert(isIndexed());
-    assert(getMapEntry()->getValue().isIndexed());
-    return getMapEntry()->second.Index;
+    assert(getEntry().isIndexed() && "Index is not set!");
+    return getEntry().Index;
+  }
+
+  /// \returns string.
+  StringRef getString() const {
+    if (MapEntry.is<StringEntryPtr>())
+      return MapEntry.get<StringEntryPtr>()->first();
+    else
+      return MapEntry.get<ShortStringEntryPtr>()->first();
+  }
+
+  /// \returns the entire string pool entry for convenience.
+  const DwarfStringPoolEntry &getEntry() const {
+    if (MapEntry.is<StringEntryPtr>())
+      return MapEntry.get<StringEntryPtr>()->second;
+    else {
+      assert(MapEntry.get<ShortStringEntryPtr>()->second != nullptr);
+      return *MapEntry.get<ShortStringEntryPtr>()->second;
+    }
   }
-  StringRef getString() const { return getMapEntry()->first(); }
-  /// Return the entire string pool entry for convenience.
-  DwarfStringPoolEntry getEntry() const { return getMapEntry()->getValue(); }
 
   bool operator==(const DwarfStringPoolEntryRef &X) const {
-    return getMapEntry() == X.getMapEntry();
+    return MapEntry.getOpaqueValue() == X.MapEntry.getOpaqueValue();
   }
+
   bool operator!=(const DwarfStringPoolEntryRef &X) const {
-    return getMapEntry() != X.getMapEntry();
+    return MapEntry.getOpaqueValue() != X.MapEntry.getOpaqueValue();
   }
 };
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
@@ -39,7 +39,7 @@
 DwarfStringPool::EntryRef DwarfStringPool::getEntry(AsmPrinter &Asm,
                                                     StringRef Str) {
   auto &MapEntry = getEntryImpl(Asm, Str);
-  return EntryRef(MapEntry, false);
+  return EntryRef(MapEntry);
 }
 
 DwarfStringPool::EntryRef DwarfStringPool::getIndexedEntry(AsmPrinter &Asm,
@@ -47,7 +47,7 @@
   auto &MapEntry = getEntryImpl(Asm, Str);
   if (!MapEntry.getValue().isIndexed())
     MapEntry.getValue().Index = NumIndexedStrings++;
-  return EntryRef(MapEntry, true);
+  return EntryRef(MapEntry);
 }
 
 void DwarfStringPool::emitStringOffsetsTableHeader(AsmPrinter &Asm,
diff --git a/llvm/lib/CodeGen/NonRelocatableStringpool.cpp b/llvm/lib/CodeGen/NonRelocatableStringpool.cpp
--- a/llvm/lib/CodeGen/NonRelocatableStringpool.cpp
+++ b/llvm/lib/CodeGen/NonRelocatableStringpool.cpp
@@ -25,7 +25,7 @@
     Entry.Symbol = nullptr;
     CurrentEndOffset += S.size() + 1;
   }
-  return DwarfStringPoolEntryRef(*I.first, true);
+  return DwarfStringPoolEntryRef(*I.first);
 }
 
 StringRef NonRelocatableStringpool::internString(StringRef S) {
@@ -44,7 +44,7 @@
   Result.reserve(Strings.size());
   for (const auto &E : Strings)
     if (E.getValue().isIndexed())
-      Result.emplace_back(E, true);
+      Result.emplace_back(E);
   llvm::sort(Result, [](const DwarfStringPoolEntryRef A,
                         const DwarfStringPoolEntryRef B) {
     return A.getIndex() < B.getIndex();
diff --git a/llvm/unittests/CodeGen/DIEHashTest.cpp b/llvm/unittests/CodeGen/DIEHashTest.cpp
--- a/llvm/unittests/CodeGen/DIEHashTest.cpp
+++ b/llvm/unittests/CodeGen/DIEHashTest.cpp
@@ -41,8 +41,8 @@
 public:
   DIEString getString(StringRef S) {
     DwarfStringPoolEntry Entry = {nullptr, 1, 1};
-    return DIEString(DwarfStringPoolEntryRef(
-        *Pool.insert(std::make_pair(S, Entry)).first, Entry.isIndexed()));
+    return DIEString(
+        DwarfStringPoolEntryRef(*Pool.insert(std::make_pair(S, Entry)).first));
   }
 
   AsmPrinter *getAsmPrinter() {