diff --git a/llvm/include/llvm/Bitcode/BitcodeReader.h b/llvm/include/llvm/Bitcode/BitcodeReader.h
--- a/llvm/include/llvm/Bitcode/BitcodeReader.h
+++ b/llvm/include/llvm/Bitcode/BitcodeReader.h
@@ -255,6 +255,8 @@
     return false;
   }
 
+  APInt readWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits);
+
   const std::error_category &BitcodeErrorCategory();
   enum class BitcodeError { CorruptedBitcode = 1 };
   inline std::error_code make_error_code(BitcodeError E) {
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -348,22 +348,26 @@
   friend class LLVMContextImpl;
   friend class MDNode;
 
-  int64_t Value;
-  DIEnumerator(LLVMContext &C, StorageType Storage, int64_t Value,
+  APInt Value;
+  DIEnumerator(LLVMContext &C, StorageType Storage, APInt Value,
                bool IsUnsigned, ArrayRef<Metadata *> Ops)
       : DINode(C, DIEnumeratorKind, Storage, dwarf::DW_TAG_enumerator, Ops),
         Value(Value) {
     SubclassData32 = IsUnsigned;
   }
+  DIEnumerator(LLVMContext &C, StorageType Storage, int64_t Value,
+               bool IsUnsigned, ArrayRef<Metadata *> Ops)
+      : DIEnumerator(C, Storage, APInt(64, Value, !IsUnsigned), IsUnsigned,
+                     Ops) {}
   ~DIEnumerator() = default;
 
-  static DIEnumerator *getImpl(LLVMContext &Context, int64_t Value,
+  static DIEnumerator *getImpl(LLVMContext &Context, APInt Value,
                                bool IsUnsigned, StringRef Name,
                                StorageType Storage, bool ShouldCreate = true) {
     return getImpl(Context, Value, IsUnsigned,
                    getCanonicalMDString(Context, Name), Storage, ShouldCreate);
   }
-  static DIEnumerator *getImpl(LLVMContext &Context, int64_t Value,
+  static DIEnumerator *getImpl(LLVMContext &Context, APInt Value,
                                bool IsUnsigned, MDString *Name,
                                StorageType Storage, bool ShouldCreate = true);
 
@@ -372,14 +376,22 @@
   }
 
 public:
-  DEFINE_MDNODE_GET(DIEnumerator, (int64_t Value, bool IsUnsigned, StringRef Name),
+  DEFINE_MDNODE_GET(DIEnumerator,
+                    (int64_t Value, bool IsUnsigned, StringRef Name),
+                    (APInt(64, Value, !IsUnsigned), IsUnsigned, Name))
+  DEFINE_MDNODE_GET(DIEnumerator,
+                    (int64_t Value, bool IsUnsigned, MDString *Name),
+                    (APInt(64, Value, !IsUnsigned), IsUnsigned, Name))
+  DEFINE_MDNODE_GET(DIEnumerator,
+                    (APInt Value, bool IsUnsigned, StringRef Name),
                     (Value, IsUnsigned, Name))
-  DEFINE_MDNODE_GET(DIEnumerator, (int64_t Value, bool IsUnsigned, MDString *Name),
+  DEFINE_MDNODE_GET(DIEnumerator,
+                    (APInt Value, bool IsUnsigned, MDString *Name),
                     (Value, IsUnsigned, Name))
 
   TempDIEnumerator clone() const { return cloneImpl(); }
 
-  int64_t getValue() const { return Value; }
+  const APInt &getValue() const { return Value; }
   bool isUnsigned() const { return SubclassData32; }
   StringRef getName() const { return getStringOperand(0); }
 
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -3872,6 +3872,10 @@
   DISPFlagField() : MDFieldImpl(DISubprogram::SPFlagZero) {}
 };
 
+struct MDAPSIntField : public MDFieldImpl<APSInt> {
+  MDAPSIntField() : ImplTy(APSInt()) {}
+};
+
 struct MDSignedField : public MDFieldImpl<int64_t> {
   int64_t Min;
   int64_t Max;
@@ -3951,6 +3955,16 @@
 namespace llvm {
 
 template <>
+bool LLParser::ParseMDField(LocTy Loc, StringRef Name, MDAPSIntField &Result) {
+  if (Lex.getKind() != lltok::APSInt)
+    return TokError("expected integer");
+
+  Result.assign(Lex.getAPSIntVal());
+  Lex.Lex();
+  return false;
+}
+
+template <>
 bool LLParser::ParseMDField(LocTy Loc, StringRef Name,
                             MDUnsignedField &Result) {
   if (Lex.getKind() != lltok::APSInt || Lex.getAPSIntVal().isSigned())
@@ -4282,27 +4296,6 @@
 }
 
 template <>
-bool LLParser::ParseMDField(LocTy Loc, StringRef Name,
-                            MDSignedOrUnsignedField &Result) {
-  if (Lex.getKind() != lltok::APSInt)
-    return false;
-
-  if (Lex.getAPSIntVal().isSigned()) {
-    MDSignedField Res = Result.A;
-    if (ParseMDField(Loc, Name, Res))
-      return true;
-    Result.assign(Res);
-    return false;
-  }
-
-  MDUnsignedField Res = Result.B;
-  if (ParseMDField(Loc, Name, Res))
-    return true;
-  Result.assign(Res);
-  return false;
-}
-
-template <>
 bool LLParser::ParseMDField(LocTy Loc, StringRef Name, MDStringField &Result) {
   LocTy ValueLoc = Lex.getLoc();
   std::string S;
@@ -4475,17 +4468,20 @@
 bool LLParser::ParseDIEnumerator(MDNode *&Result, bool IsDistinct) {
 #define VISIT_MD_FIELDS(OPTIONAL, REQUIRED)                                    \
   REQUIRED(name, MDStringField, );                                             \
-  REQUIRED(value, MDSignedOrUnsignedField, );                                  \
+  REQUIRED(value, MDAPSIntField, );                                            \
   OPTIONAL(isUnsigned, MDBoolField, (false));
   PARSE_MD_FIELDS();
 #undef VISIT_MD_FIELDS
 
-  if (isUnsigned.Val && value.isMDSignedField())
+  if (isUnsigned.Val && value.Val.isNegative())
     return TokError("unsigned enumerator with negative value");
 
-  int64_t Value = value.isMDSignedField()
-                      ? value.getMDSignedValue()
-                      : static_cast<int64_t>(value.getMDUnsignedValue());
+  APSInt Value(value.Val);
+  // Add a leading zero so that unsigned values with the msb set are not
+  // mistaken for negative values when used for signed enumerators.
+  if (!isUnsigned.Val && value.Val.isUnsigned() && value.Val.isSignBitSet())
+    Value = Value.zext(Value.getBitWidth() + 1);
+
   Result =
       GET_OR_DISTINCT(DIEnumerator, (Context, Value, isUnsigned.Val, name.Val));
 
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2317,7 +2317,7 @@
   return Error::success();
 }
 
-static APInt readWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
+APInt llvm::readWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
   SmallVector<uint64_t, 8> Words(Vals.size());
   transform(Vals, Words.begin(),
                  BitcodeReader::decodeSignRotatedValue);
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1277,14 +1277,24 @@
     break;
   }
   case bitc::METADATA_ENUMERATOR: {
-    if (Record.size() != 3)
+    if (Record.size() < 3)
       return error("Invalid record");
 
     IsDistinct = Record[0] & 1;
     bool IsUnsigned = Record[0] & 2;
+    bool IsBigInt = Record[0] & 4;
+    APInt Value;
+
+    if (IsBigInt) {
+      const uint64_t BitWidth = Record[1];
+      const size_t NumWords = Record.size() - 3;
+      Value = readWideAPInt(makeArrayRef(&Record[3], NumWords), BitWidth);
+    } else
+      Value = APInt(64, unrotateSign(Record[1]), !IsUnsigned);
+
     MetadataList.assignValue(
-        GET_OR_DISTINCT(DIEnumerator, (Context, unrotateSign(Record[1]),
-                                       IsUnsigned, getMDString(Record[2]))),
+        GET_OR_DISTINCT(DIEnumerator,
+                        (Context, Value, IsUnsigned, getMDString(Record[2]))),
         NextMetadataNo);
     NextMetadataNo++;
     break;
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1529,12 +1529,32 @@
   Record.clear();
 }
 
+static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
+  if ((int64_t)V >= 0)
+    Vals.push_back(V << 1);
+  else
+    Vals.push_back((-V << 1) | 1);
+}
+
+static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A) {
+  // We have an arbitrary precision integer value to write whose
+  // bit width is > 64. However, in canonical unsigned integer
+  // format it is likely that the high bits are going to be zero.
+  // So, we only write the number of active words.
+  unsigned NumWords = A.getActiveWords();
+  const uint64_t *RawData = A.getRawData();
+  for (unsigned i = 0; i < NumWords; i++)
+    emitSignedInt64(Vals, RawData[i]);
+}
+
 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
                                             SmallVectorImpl<uint64_t> &Record,
                                             unsigned Abbrev) {
-  Record.push_back((N->isUnsigned() << 1) | N->isDistinct());
-  Record.push_back(rotateSign(N->getValue()));
+  const uint64_t IsBigInt = 1 << 2;
+  Record.push_back(IsBigInt | (N->isUnsigned() << 1) | N->isDistinct());
+  Record.push_back(N->getValue().getBitWidth());
   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
+  emitWideAPInt(Record, N->getValue());
 
   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
   Record.clear();
@@ -2269,13 +2289,6 @@
   Stream.ExitBlock();
 }
 
-static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
-  if ((int64_t)V >= 0)
-    Vals.push_back(V << 1);
-  else
-    Vals.push_back((-V << 1) | 1);
-}
-
 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
                                          bool isGlobal) {
   if (FirstVal == LastVal) return;
@@ -2362,15 +2375,7 @@
         Code = bitc::CST_CODE_INTEGER;
         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
       } else {                             // Wide integers, > 64 bits in size.
-        // We have an arbitrary precision integer value to write whose
-        // bit width is > 64. However, in canonical unsigned integer
-        // format it is likely that the high bits are going to be zero.
-        // So, we only write the number of active words.
-        unsigned NWords = IV->getValue().getActiveWords();
-        const uint64_t *RawWords = IV->getValue().getRawData();
-        for (unsigned i = 0; i != NWords; ++i) {
-          emitSignedInt64(Record, RawWords[i]);
-        }
+        emitWideAPInt(Record, IV->getValue());
         Code = bitc::CST_CODE_WIDE_INTEGER;
       }
     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -2080,7 +2080,7 @@
       // order, which is what MSVC does.
       if (auto *Enumerator = dyn_cast_or_null<DIEnumerator>(Element)) {
         EnumeratorRecord ER(MemberAccess::Public,
-                            APSInt::getUnsigned(Enumerator->getValue()),
+                            APSInt(Enumerator->getValue(), true),
                             Enumerator->getName());
         ContinuationBuilder.writeMemberType(ER);
         EnumeratorCount++;
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1449,8 +1449,7 @@
       DIE &Enumerator = createAndAddDIE(dwarf::DW_TAG_enumerator, Buffer);
       StringRef Name = Enum->getName();
       addString(Enumerator, dwarf::DW_AT_name, Name);
-      auto Value = static_cast<uint64_t>(Enum->getValue());
-      addConstantValue(Enumerator, IsUnsigned, Value);
+      addConstantValue(Enumerator, Enum->getValue(), IsUnsigned);
       if (IndexEnumerators)
         addGlobalName(Name, Enumerator, Context);
     }
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -1647,6 +1647,8 @@
                      bool ShouldSkipNull = true);
   template <class IntTy>
   void printInt(StringRef Name, IntTy Int, bool ShouldSkipZero = true);
+  void printAPInt(StringRef Name, APInt Int, bool IsUnsigned,
+                  bool ShouldSkipZero);
   void printBool(StringRef Name, bool Value, Optional<bool> Default = None);
   void printDIFlags(StringRef Name, DINode::DIFlags Flags);
   void printDISPFlags(StringRef Name, DISubprogram::DISPFlags Flags);
@@ -1722,6 +1724,15 @@
   Out << FS << Name << ": " << Int;
 }
 
+void MDFieldPrinter::printAPInt(StringRef Name, APInt Int, bool IsUnsigned,
+                                bool ShouldSkipZero) {
+  if (ShouldSkipZero && Int.isNullValue())
+    return;
+
+  Out << FS << Name << ": ";
+  Int.print(Out, !IsUnsigned);
+}
+
 void MDFieldPrinter::printBool(StringRef Name, bool Value,
                                Optional<bool> Default) {
   if (Default && Value == *Default)
@@ -1851,13 +1862,10 @@
   Out << "!DIEnumerator(";
   MDFieldPrinter Printer(Out);
   Printer.printString("name", N->getName(), /* ShouldSkipEmpty */ false);
-  if (N->isUnsigned()) {
-    auto Value = static_cast<uint64_t>(N->getValue());
-    Printer.printInt("value", Value, /* ShouldSkipZero */ false);
+  Printer.printAPInt("value", N->getValue(), N->isUnsigned(),
+                     /*ShouldSkipZero=*/false);
+  if (N->isUnsigned())
     Printer.printBool("isUnsigned", true);
-  } else {
-    Printer.printInt("value", N->getValue(), /* ShouldSkipZero */ false);
-  }
   Out << ")";
 }
 
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -246,7 +246,8 @@
 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, int64_t Val,
                                           bool IsUnsigned) {
   assert(!Name.empty() && "Unable to create enumerator without name");
-  return DIEnumerator::get(VMContext, Val, IsUnsigned, Name);
+  return DIEnumerator::get(VMContext, APInt(64, Val, !IsUnsigned), IsUnsigned,
+                           Name);
 }
 
 DIBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
--- a/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -347,7 +347,7 @@
   DEFINE_GETIMPL_STORE(DISubrange, (CountNode, Lo), Ops);
 }
 
-DIEnumerator *DIEnumerator::getImpl(LLVMContext &Context, int64_t Value,
+DIEnumerator *DIEnumerator::getImpl(LLVMContext &Context, APInt Value,
                                     bool IsUnsigned, MDString *Name,
                                     StorageType Storage, bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
diff --git a/llvm/lib/IR/LLVMContextImpl.h b/llvm/lib/IR/LLVMContextImpl.h
--- a/llvm/lib/IR/LLVMContextImpl.h
+++ b/llvm/lib/IR/LLVMContextImpl.h
@@ -355,19 +355,22 @@
 };
 
 template <> struct MDNodeKeyImpl<DIEnumerator> {
-  int64_t Value;
+  APInt Value;
   MDString *Name;
   bool IsUnsigned;
 
-  MDNodeKeyImpl(int64_t Value, bool IsUnsigned, MDString *Name)
+  MDNodeKeyImpl(APInt Value, bool IsUnsigned, MDString *Name)
       : Value(Value), Name(Name), IsUnsigned(IsUnsigned) {}
+  MDNodeKeyImpl(int64_t Value, bool IsUnsigned, MDString *Name)
+      : Value(APInt(64, Value, !IsUnsigned)), Name(Name),
+        IsUnsigned(IsUnsigned) {}
   MDNodeKeyImpl(const DIEnumerator *N)
       : Value(N->getValue()), Name(N->getRawName()),
         IsUnsigned(N->isUnsigned()) {}
 
   bool isKeyOf(const DIEnumerator *RHS) const {
-    return Value == RHS->getValue() && IsUnsigned == RHS->isUnsigned() &&
-           Name == RHS->getRawName();
+    return APInt::isSameValue(Value, RHS->getValue()) &&
+           IsUnsigned == RHS->isUnsigned() && Name == RHS->getRawName();
   }
 
   unsigned getHashValue() const { return hash_combine(Value, Name); }
diff --git a/llvm/lib/Target/BPF/BTFDebug.cpp b/llvm/lib/Target/BPF/BTFDebug.cpp
--- a/llvm/lib/Target/BPF/BTFDebug.cpp
+++ b/llvm/lib/Target/BPF/BTFDebug.cpp
@@ -171,7 +171,12 @@
     struct BTF::BTFEnum BTFEnum;
     BTFEnum.NameOff = BDebug.addString(Enum->getName());
     // BTF enum value is 32bit, enforce it.
-    BTFEnum.Val = static_cast<uint32_t>(Enum->getValue());
+    uint32_t Value;
+    if (Enum->isUnsigned())
+      Value = static_cast<uint32_t>(Enum->getValue().getZExtValue());
+    else
+      Value = static_cast<uint32_t>(Enum->getValue().getSExtValue());
+    BTFEnum.Val = Value;
     EnumValues.push_back(BTFEnum);
   }
 }
diff --git a/llvm/test/Assembler/DIEnumeratorBig.ll b/llvm/test/Assembler/DIEnumeratorBig.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Assembler/DIEnumeratorBig.ll
@@ -0,0 +1,13 @@
+;; Round-trip test for enumeration members using more than 64 bits.
+
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
+
+!named = !{!0, !1, !2}
+
+; CHECK: !DIEnumerator(name: "D0", value: -170141183460469231731687303715884105728)
+; CHECK: !DIEnumerator(name: "D1", value: 170141183460469231731687303715884105727)
+!0 = !DIEnumerator(name: "D0", value: -170141183460469231731687303715884105728)
+!1 = !DIEnumerator(name: "D1", value: 170141183460469231731687303715884105727)
+
+; CHECK: !DIEnumerator(name: "D1", value: 2722258935367507707706996859454145691648, isUnsigned: true)
+!2 = !DIEnumerator(name: "D1", value: 2722258935367507707706996859454145691648, isUnsigned: true)
diff --git a/llvm/test/Bitcode/DIEnumerator-10.0.ll b/llvm/test/Bitcode/DIEnumerator-10.0.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Bitcode/DIEnumerator-10.0.ll
@@ -0,0 +1,10 @@
+;; DIEnumerator-10.0.ll.bc was generated by llvm-as 10.0.0
+; RUN: llvm-dis < %s.bc | FileCheck %s
+; RUN: verify-uselistorder < %s.bc
+
+!named = !{!0, !1}
+
+; CHECK: !DIEnumerator(name: "A0", value: 9223372036854775807)
+!0 = !DIEnumerator(name: "A0", value: 9223372036854775807)
+; CHECK: !DIEnumerator(name: "B0", value: -9223372036854775808)
+!1 = !DIEnumerator(name: "B0", value: -9223372036854775808)
diff --git a/llvm/test/Bitcode/DIEnumerator-10.0.ll.bc b/llvm/test/Bitcode/DIEnumerator-10.0.ll.bc
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
GIT binary patch
literal 0
Hc$@<O00001

literal 0
Hc$@<O00001

diff --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -1186,7 +1186,7 @@
 TEST_F(DIEnumeratorTest, get) {
   auto *N = DIEnumerator::get(Context, 7, false, "name");
   EXPECT_EQ(dwarf::DW_TAG_enumerator, N->getTag());
-  EXPECT_EQ(7, N->getValue());
+  EXPECT_EQ(7, N->getValue().getSExtValue());
   EXPECT_FALSE(N->isUnsigned());
   EXPECT_EQ("name", N->getName());
   EXPECT_EQ(N, DIEnumerator::get(Context, 7, false, "name"));
@@ -1199,6 +1199,15 @@
   EXPECT_EQ(N, MDNode::replaceWithUniqued(std::move(Temp)));
 }
 
+TEST_F(DIEnumeratorTest, getWithLargeValues) {
+  auto *N = DIEnumerator::get(Context, APInt::getMaxValue(128), false, "val");
+  EXPECT_EQ(128U, N->getValue().countPopulation());
+  EXPECT_EQ(N,
+            DIEnumerator::get(Context, APInt::getMaxValue(128), false, "val"));
+  EXPECT_NE(N,
+            DIEnumerator::get(Context, APInt::getMinValue(128), false, "val"));
+}
+
 typedef MetadataTest DIBasicTypeTest;
 
 TEST_F(DIBasicTypeTest, get) {