diff --git a/llvm/include/llvm/ProfileData/InstrProfCorrelator.h b/llvm/include/llvm/ProfileData/InstrProfCorrelator.h
--- a/llvm/include/llvm/ProfileData/InstrProfCorrelator.h
+++ b/llvm/include/llvm/ProfileData/InstrProfCorrelator.h
@@ -12,6 +12,7 @@
 #ifndef LLVM_PROFILEDATA_INSTRPROFCORRELATOR_H
 #define LLVM_PROFILEDATA_INSTRPROFCORRELATOR_H
 
+#include "llvm/ADT/StringSet.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/Object/Binary.h"
 #include "llvm/Object/ObjectFile.h"
@@ -105,11 +106,13 @@
   void addProbe(StringRef FunctionName, uint64_t CFGHash, IntPtrT CounterOffset,
                 IntPtrT FunctionPtr, uint32_t NumCounters);
 
+  bool hasProbe(StringRef FunctionName) const;
+
 private:
   InstrProfCorrelatorImpl(InstrProfCorrelatorKind Kind,
                           std::unique_ptr<InstrProfCorrelator::Context> Ctx)
       : InstrProfCorrelator(Kind, std::move(Ctx)){};
-  std::vector<std::string> Names;
+  llvm::StringSet<> Names;
 
   // Byte-swap the value if necessary.
   template <class T> T maybeSwap(T Value) const {
diff --git a/llvm/lib/ProfileData/InstrProfCorrelator.cpp b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
--- a/llvm/lib/ProfileData/InstrProfCorrelator.cpp
+++ b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
@@ -127,8 +127,9 @@
 Error InstrProfCorrelatorImpl<IntPtrT>::correlateProfileData() {
   assert(Data.empty() && CompressedNames.empty() && Names.empty());
   correlateProfileDataImpl();
-  auto Result =
-      collectPGOFuncNameStrings(Names, /*doCompression=*/true, CompressedNames);
+  std::vector<std::string> NamesVec(Names.keys().begin(), Names.keys().end());
+  auto Result = collectPGOFuncNameStrings(NamesVec, /*doCompression=*/true,
+                                          CompressedNames);
   Names.clear();
   return Result;
 }
@@ -139,6 +140,7 @@
                                                 IntPtrT CounterOffset,
                                                 IntPtrT FunctionPtr,
                                                 uint32_t NumCounters) {
+  assert(!hasProbe(FunctionName));
   Data.push_back({
       maybeSwap<uint64_t>(IndexedInstrProf::ComputeHash(FunctionName)),
       maybeSwap<uint64_t>(CFGHash),
@@ -151,7 +153,12 @@
       maybeSwap<uint32_t>(NumCounters),
       /*NumValueSites=*/{maybeSwap<uint16_t>(0), maybeSwap<uint16_t>(0)},
   });
-  Names.push_back(FunctionName.str());
+  Names.insert(FunctionName);
+}
+
+template <class IntPtrT>
+bool InstrProfCorrelatorImpl<IntPtrT>::hasProbe(StringRef FunctionName) const {
+  return Names.contains(FunctionName);
 }
 
 template <class IntPtrT>
@@ -219,6 +226,8 @@
         if (auto EC =
                 AnnotationFormValue->getAsCString().moveInto(FunctionName))
           consumeError(std::move(EC));
+        if (this->hasProbe(*FunctionName))
+          return;
       } else if (AnnotationName.compare(
                      InstrProfCorrelator::CFGHashAttributeName) == 0) {
         CFGHash = AnnotationFormValue->getAsUnsignedConstant();