Index: llvm/include/llvm/DWARFLinker/DWARFLinkerCompileUnit.h
===================================================================
--- llvm/include/llvm/DWARFLinker/DWARFLinkerCompileUnit.h
+++ llvm/include/llvm/DWARFLinker/DWARFLinkerCompileUnit.h
@@ -78,6 +78,9 @@
 
     /// Is ODR marking done?
     bool ODRMarkingDone : 1;
+
+    /// Is this a reference to a DIE that hasn't been cloned yet?
+    bool UnclonedReference : 1;
   };
 
   CompileUnit(DWARFUnit &OrigUnit, unsigned ID, bool CanUseODR,
Index: llvm/lib/DWARFLinker/DWARFLinker.cpp
===================================================================
--- llvm/lib/DWARFLinker/DWARFLinker.cpp
+++ llvm/lib/DWARFLinker/DWARFLinker.cpp
@@ -935,9 +935,9 @@
   }
 
   if (!RefInfo.Clone) {
-    assert(Ref > InputDIE.getOffset());
     // We haven't cloned this DIE yet. Just create an empty one and
     // store it. It'll get really cloned when we process it.
+    RefInfo.UnclonedReference = true;
     RefInfo.Clone = DIE::get(DIEAlloc, dwarf::Tag(RefDie.getTag()));
   }
   NewRefDie = RefInfo.Clone;
@@ -950,8 +950,8 @@
     // FIXME: we should be able to design DIEEntry reliance on
     // DwarfDebug away.
     uint64_t Attr;
-    if (Ref < InputDIE.getOffset()) {
-      // We must have already cloned that DIE.
+    if (Ref < InputDIE.getOffset() && !RefInfo.UnclonedReference) {
+      // We have already cloned that DIE.
       uint32_t NewRefOffset =
           RefUnit->getStartOffset() + NewRefDie->getOffset();
       Attr = NewRefOffset;