diff --git a/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp b/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
--- a/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/DataExtractor.h"
@@ -16,6 +17,7 @@
 #include <cassert>
 #include <cinttypes>
 #include <cstdint>
+#include <set>
 #include <utility>
 
 using namespace llvm;
@@ -166,25 +168,26 @@
   // for both a string and a CU vector.
   uint32_t SymTableSize = (ConstantPoolOffset - SymbolTableOffset) / 8;
   SymbolTable.reserve(SymTableSize);
-  uint32_t CuVectorsTotal = 0;
+  std::set<uint32_t> CUOffsets;
   for (uint32_t i = 0; i < SymTableSize; ++i) {
     uint32_t NameOffset = Data.getU32(&Offset);
     uint32_t CuVecOffset = Data.getU32(&Offset);
     SymbolTable.push_back({NameOffset, CuVecOffset});
     if (NameOffset || CuVecOffset)
-      ++CuVectorsTotal;
+      CUOffsets.insert(CuVecOffset);
   }
 
   // The constant pool. CU vectors are stored first, followed by strings.
   // The first value is the number of CU indices in the vector. Each subsequent
   // value is the index and symbol attributes of a CU in the CU list.
-  for (uint32_t i = 0; i < CuVectorsTotal; ++i) {
+  for (auto CUOffset : CUOffsets) {
+    Offset = ConstantPoolOffset + CUOffset;
     ConstantPoolVectors.emplace_back(0, SmallVector<uint32_t, 0>());
     auto &Vec = ConstantPoolVectors.back();
     Vec.first = Offset - ConstantPoolOffset;
 
     uint32_t Num = Data.getU32(&Offset);
-    for (uint32_t j = 0; j < Num; ++j)
+    for (uint32_t J = 0; J < Num; ++J)
       Vec.second.push_back(Data.getU32(&Offset));
   }