diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -476,8 +476,7 @@
   case dwarf::DW_FORM_data8:
     return 8;
   case dwarf::DW_FORM_sec_offset:
-    // FIXME: add support for DWARF64
-    return 4;
+    return AP->getDwarfOffsetByteSize();
   default:
     llvm_unreachable("DIE Value form not supported yet");
   }
@@ -505,8 +504,7 @@
     return 4;
   case dwarf::DW_FORM_sec_offset:
   case dwarf::DW_FORM_strp:
-    // FIXME: add support for DWARF64
-    return 4;
+    return AP->getDwarfOffsetByteSize();
   case dwarf::DW_FORM_addr:
     return AP->MAI->getCodePointerSize();
   default:
@@ -551,8 +549,7 @@
   case dwarf::DW_FORM_data4:
     return 4;
   case dwarf::DW_FORM_sec_offset:
-    // FIXME: add support for DWARF64
-    return 4;
+    return AP->getDwarfOffsetByteSize();
   default:
     llvm_unreachable("DIE Value form not supported yet");
   }
@@ -822,10 +819,17 @@
   case dwarf::DW_FORM_loclistx:
     return getULEB128Size(Index);
   case dwarf::DW_FORM_data4:
+    assert(!AP->isDwarf64() &&
+           "DW_FORM_data4 is not suitable to emit a pointer to a location list "
+           "in the 64-bit DWARF format");
     return 4;
+  case dwarf::DW_FORM_data8:
+    assert(AP->isDwarf64() &&
+           "DW_FORM_data8 is not suitable to emit a pointer to a location list "
+           "in the 32-bit DWARF format");
+    return 8;
   case dwarf::DW_FORM_sec_offset:
-    // FIXME: add support for DWARF64
-    return 4;
+    return AP->getDwarfOffsetByteSize();
   default:
     llvm_unreachable("DIE Value form not supported yet");
   }
diff --git a/llvm/unittests/CodeGen/CMakeLists.txt b/llvm/unittests/CodeGen/CMakeLists.txt
--- a/llvm/unittests/CodeGen/CMakeLists.txt
+++ b/llvm/unittests/CodeGen/CMakeLists.txt
@@ -17,6 +17,7 @@
   AArch64SelectionDAGTest.cpp
   AsmPrinterDwarfTest.cpp
   DIEHashTest.cpp
+  DIETest.cpp
   LowLevelTypeTest.cpp
   LexicalScopesTest.cpp
   MachineInstrBundleIteratorTest.cpp
diff --git a/llvm/unittests/CodeGen/DIETest.cpp b/llvm/unittests/CodeGen/DIETest.cpp
new file mode 100644
--- /dev/null
+++ b/llvm/unittests/CodeGen/DIETest.cpp
@@ -0,0 +1,189 @@
+//===- llvm/unittest/CodeGen/DIETest.cpp ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/DIE.h"
+#include "TestAsmPrinter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/Testing/Support/Error.h"
+
+using namespace llvm;
+using testing::_;
+using testing::SaveArg;
+
+namespace {
+
+using DIETestParams =
+    std::tuple<unsigned, dwarf::DwarfFormat, dwarf::Form, unsigned>;
+
+class DIEFixtureBase : public testing::TestWithParam<DIETestParams> {
+protected:
+  void SetUp() override {
+    unsigned Version;
+    dwarf::DwarfFormat Format;
+    std::tie(Version, Format, Form, Size) = GetParam();
+    auto ExpectedTestPrinter =
+        TestAsmPrinter::create("x86_64-pc-linux", Version, Format);
+    ASSERT_THAT_EXPECTED(ExpectedTestPrinter, Succeeded());
+    TestPrinter = std::move(ExpectedTestPrinter.get());
+  }
+
+  dwarf::Form Form;
+  unsigned Size;
+  std::unique_ptr<TestAsmPrinter> TestPrinter;
+};
+
+struct DIEExprFixture : public DIEFixtureBase {
+  void SetUp() override {
+    DIEFixtureBase::SetUp();
+    if (!TestPrinter)
+      return;
+
+    Val = MCConstantExpr::create(42, TestPrinter->getCtx());
+  }
+
+  const MCExpr *Val = nullptr;
+};
+
+TEST_P(DIEExprFixture, SizeOf) {
+  if (!TestPrinter)
+    return;
+
+  DIEExpr Tst(Val);
+  EXPECT_EQ(Size, Tst.SizeOf(TestPrinter->getAP(), Form));
+}
+
+TEST_P(DIEExprFixture, EmitValue) {
+  if (!TestPrinter)
+    return;
+
+  DIEExpr Tst(Val);
+  EXPECT_CALL(TestPrinter->getMS(), emitValueImpl(Val, Size, _));
+  Tst.emitValue(TestPrinter->getAP(), Form);
+}
+
+INSTANTIATE_TEST_CASE_P(
+    DIETestParams, DIEExprFixture,
+    testing::Values(
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_data8, 8u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_sec_offset, 4u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_data8, 8u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_sec_offset, 8u}), );
+
+struct DIELabelFixture : public DIEFixtureBase {
+  void SetUp() override {
+    DIEFixtureBase::SetUp();
+    if (!TestPrinter)
+      return;
+
+    Val = TestPrinter->getCtx().createTempSymbol();
+  }
+
+  const MCSymbol *Val = nullptr;
+};
+
+TEST_P(DIELabelFixture, SizeOf) {
+  if (!TestPrinter)
+    return;
+
+  DIELabel Tst(Val);
+  EXPECT_EQ(Size, Tst.SizeOf(TestPrinter->getAP(), Form));
+}
+
+TEST_P(DIELabelFixture, EmitValue) {
+  if (!TestPrinter)
+    return;
+
+  DIELabel Tst(Val);
+
+  const MCExpr *Arg0 = nullptr;
+  EXPECT_CALL(TestPrinter->getMS(), emitValueImpl(_, Size, _))
+      .WillOnce(SaveArg<0>(&Arg0));
+  Tst.emitValue(TestPrinter->getAP(), Form);
+
+  const MCSymbolRefExpr *ActualArg0 = dyn_cast_or_null<MCSymbolRefExpr>(Arg0);
+  ASSERT_NE(ActualArg0, nullptr);
+  EXPECT_EQ(&(ActualArg0->getSymbol()), Val);
+}
+
+INSTANTIATE_TEST_CASE_P(
+    DIETestParams, DIELabelFixture,
+    testing::Values(
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_sec_offset, 4u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_strp, 4u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_addr, 8u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_sec_offset, 8u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_strp, 8u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_addr, 8u}), );
+
+struct DIEDeltaFixture : public DIEFixtureBase {
+  void SetUp() override {
+    DIEFixtureBase::SetUp();
+    if (!TestPrinter)
+      return;
+
+    Hi = TestPrinter->getCtx().createTempSymbol();
+    Lo = TestPrinter->getCtx().createTempSymbol();
+  }
+
+  const MCSymbol *Hi = nullptr;
+  const MCSymbol *Lo = nullptr;
+};
+
+TEST_P(DIEDeltaFixture, SizeOf) {
+  if (!TestPrinter)
+    return;
+
+  DIEDelta Tst(Hi, Lo);
+  EXPECT_EQ(Size, Tst.SizeOf(TestPrinter->getAP(), Form));
+}
+
+TEST_P(DIEDeltaFixture, EmitValue) {
+  if (!TestPrinter)
+    return;
+
+  DIEDelta Tst(Hi, Lo);
+  EXPECT_CALL(TestPrinter->getMS(), emitAbsoluteSymbolDiff(Hi, Lo, Size));
+  Tst.emitValue(TestPrinter->getAP(), Form);
+}
+
+INSTANTIATE_TEST_CASE_P(
+    DIETestParams, DIEDeltaFixture,
+    testing::Values(
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_sec_offset, 4u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_sec_offset, 8u}), );
+
+struct DIELocListFixture : public DIEFixtureBase {
+  void SetUp() override { DIEFixtureBase::SetUp(); }
+};
+
+TEST_P(DIELocListFixture, SizeOf) {
+  if (!TestPrinter)
+    return;
+
+  DIELocList Tst(999);
+  EXPECT_EQ(Size, Tst.SizeOf(TestPrinter->getAP(), Form));
+}
+
+INSTANTIATE_TEST_CASE_P(
+    DIETestParams, DIELocListFixture,
+    testing::Values(
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_loclistx, 2u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_sec_offset, 4u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_loclistx, 2u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_data8, 8u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_sec_offset, 8u}), );
+
+} // end namespace