Index: lib/CodeGen/AsmPrinter/DIE.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DIE.cpp
+++ lib/CodeGen/AsmPrinter/DIE.cpp
@@ -42,6 +42,8 @@
   // overloads.  Otherwise MSVC 2010 thinks this call is ambiguous.
   ID.AddInteger(unsigned(Attribute));
   ID.AddInteger(unsigned(Form));
+  if (dwarf::DW_FORM_implicit_const == Form)
+    ID.AddInteger(Value);
 }
 
 //===----------------------------------------------------------------------===//
@@ -107,8 +109,12 @@
     O << "  "
       << dwarf::AttributeString(Data[i].getAttribute())
       << "  "
-      << dwarf::FormEncodingString(Data[i].getForm())
-      << '\n';
+      << dwarf::FormEncodingString(Data[i].getForm());
+
+    if (dwarf::DW_FORM_implicit_const == Data[i].getForm())
+      O << " " << Data[i].getValue();
+
+    O << '\n';
   }
 }
 
Index: unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
===================================================================
--- unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
+++ unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
@@ -1543,4 +1543,38 @@
   EXPECT_EQ(DieMangled, toString(NameOpt, ""));
 }
 
+TEST(DWARFDebugInfo, TestImplicitConstAbbrevs) {
+  uint16_t Version = 5;
+
+  const uint8_t AddrSize = sizeof(void *);
+  initLLVMIfNeeded();
+  Triple Triple = getHostTripleForAddrSize(AddrSize);
+  auto ExpectedDG = dwarfgen::Generator::create(Triple, Version);
+  if (HandleExpectedError(ExpectedDG))
+    return;
+  dwarfgen::Generator *DG = ExpectedDG.get().get();
+  dwarfgen::CompileUnit &CU = DG->addCompileUnit();
+  dwarfgen::DIE CUDie = CU.getUnitDIE();
+  uint16_t Attr = DW_AT_lo_user;
+  int64_t Val1 = 42;
+  int64_t Val2 = 43;
+
+  auto &AbbrevSet = DG->getAbbrevSet();
+  auto FirstVal1DIE = CUDie.addChild(DW_TAG_class_type);
+  FirstVal1DIE.addAttribute(Attr, DW_FORM_implicit_const, Val1);
+  auto &FirstVal1Abbrev = AbbrevSet.uniqueAbbreviation(FirstVal1DIE.getDIE());
+
+  auto SecondVal1DIE = CUDie.addChild(DW_TAG_class_type);
+  SecondVal1DIE.addAttribute(Attr, DW_FORM_implicit_const, Val1);
+  auto &SecondVal1Abbrev = AbbrevSet.uniqueAbbreviation(SecondVal1DIE.getDIE());
+
+  EXPECT_EQ(FirstVal1Abbrev.getNumber(), SecondVal1Abbrev.getNumber());
+
+  auto Val2DIE = CUDie.addChild(DW_TAG_class_type);
+  Val2DIE.addAttribute(Attr, DW_FORM_implicit_const, Val2);
+  auto &Val2Abbrev = AbbrevSet.uniqueAbbreviation(Val2DIE.getDIE());
+
+  EXPECT_NE(FirstVal1Abbrev.getNumber(), Val2Abbrev.getNumber());
+}
+
 } // end anonymous namespace
Index: unittests/DebugInfo/DWARF/DwarfGenerator.h
===================================================================
--- unittests/DebugInfo/DWARF/DwarfGenerator.h
+++ unittests/DebugInfo/DWARF/DwarfGenerator.h
@@ -132,6 +132,9 @@
   
   /// Force a DIE to say it has children even when it doesn't.
   void setForceChildren();
+
+  /// Get actual DIE object
+  llvm::DIE &getDIE() { return *Die; }
 };
 
 /// A DWARF compile unit used to generate DWARF compile/type units.