[InstrFDO][TypeProf] Implement binary instrumentation and profile read/write (#66825)

(The profile format change is split into a standalone change into https://github.com/llvm/llvm-project/pull/81691)

* For InstrFDO value profiling, implement instrumentation and lowering for virtual table address.
* This is controlled by `-enable-vtable-value-profiling` and off by default.
* When the option is on, raw profiles will carry serialized `VTableProfData` structs and compressed vtables as payloads.
 
* Implement profile reader and writer support 
  * Raw profile reader is used by `llvm-profdata` but not compiler. Raw profile reader will construct InstrProfSymtab with symbol names, and map profiled runtime address to vtable symbols.
  * Indexed profile reader is used by `llvm-profdata` and compiler. When initialized, the reader stores a pointer to the beginning of in-memory compressed vtable names and the length of string. When used in `llvm-profdata`, reader decompress the string to show symbols of a profiled site. When used in compiler, string decompression doesn't
happen since IR is used to construct InstrProfSymtab.
  * Indexed profile writer collects the list of vtable names, and stores that to index profiles.
  * Text profile reader and writer support are added but mostly follow the implementation for indirect-call value type.
* `llvm-profdata show -show-vtables <args> <profile>` is implemented.

rfc in
https://discourse.llvm.org/t/rfc-dynamic-type-profiling-and-optimizations-in-llvm/74600#pick-instrumentation-points-and-instrument-runtime-types-7

17 files changed, 1419 insertions, 192 deletions

diff --git a/compiler-rt/test/profile/Linux/instrprof-vtable-value-prof.cpp b/compiler-rt/test/profile/Linux/instrprof-vtable-value-prof.cpp
new file mode 100644
index 0000000..5c8426b
--- /dev/null
+++ b/compiler-rt/test/profile/Linux/instrprof-vtable-value-prof.cpp
@@ -0,0 +1,142 @@
+// REQUIRES: lld-available
+
+// RUN: %clangxx_pgogen -fuse-ld=lld -O2 -g -fprofile-generate=. -mllvm -enable-vtable-value-profiling %s -o %t-test
+// RUN: env LLVM_PROFILE_FILE=%t-test.profraw %t-test
+
+// Show vtable profiles from raw profile.
+// RUN: llvm-profdata show --function=main --ic-targets --show-vtables %t-test.profraw | FileCheck %s --check-prefixes=COMMON,RAW
+
+// Generate indexed profile from raw profile and show the data.
+// RUN: llvm-profdata merge %t-test.profraw -o %t-test.profdata
+// RUN: llvm-profdata show --function=main --ic-targets --show-vtables %t-test.profdata | FileCheck %s --check-prefixes=COMMON,INDEXED
+
+// Generate text profile from raw and indexed profiles respectively and show the data.
+// RUN: llvm-profdata merge --text %t-test.profraw -o %t-raw.proftext
+// RUN: llvm-profdata show --function=main --ic-targets --show-vtables --text %t-raw.proftext | FileCheck %s --check-prefix=ICTEXT
+// RUN: llvm-profdata merge --text %t-test.profdata -o %t-indexed.proftext
+// RUN: llvm-profdata show --function=main --ic-targets --show-vtables --text %t-indexed.proftext | FileCheck %s --check-prefix=ICTEXT
+
+// Generate indexed profile from text profiles and show the data
+// RUN: llvm-profdata merge --binary %t-raw.proftext -o %t-text.profraw
+// RUN: llvm-profdata show --function=main --ic-targets --show-vtables %t-text.profraw | FileCheck %s --check-prefixes=COMMON,INDEXED
+// RUN: llvm-profdata merge --binary %t-indexed.proftext -o %t-text.profdata
+// RUN: llvm-profdata show --function=main --ic-targets --show-vtables %t-text.profdata | FileCheck %s --check-prefixes=COMMON,INDEXED
+
+// COMMON: Counters:
+// COMMON-NEXT:  main:
+// COMMON-NEXT:  Hash: 0x0f9a16fe6d398548
+// COMMON-NEXT:  Counters: 2
+// COMMON-NEXT:  Indirect Call Site Count: 2
+// COMMON-NEXT:  Number of instrumented vtables: 2
+// RAW:  Indirect Target Results:
+// RAW-NEXT:       [  0, _ZN8Derived15func1Eii,        250 ] (25.00%)
+// RAW-NEXT:       [  0, {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func1Eii,        750 ] (75.00%)
+// RAW-NEXT:       [  1, _ZN8Derived15func2Eii,        250 ] (25.00%)
+// RAW-NEXT:       [  1, {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func2Eii,        750 ] (75.00%)
+// RAW-NEXT:  VTable Results:
+// RAW-NEXT:       [  0, _ZTV8Derived1,        250 ] (25.00%)
+// RAW-NEXT:       [  0, {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E,        750 ] (75.00%)
+// RAW-NEXT:       [  1, _ZTV8Derived1,        250 ] (25.00%)
+// RAW-NEXT:       [  1, {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E,        750 ] (75.00%)
+// INDEXED:     Indirect Target Results:
+// INDEXED-NEXT:         [  0, {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func1Eii,        750 ] (75.00%)
+// INDEXED-NEXT:         [  0, _ZN8Derived15func1Eii,        250 ] (25.00%)
+// INDEXED-NEXT:         [  1, {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func2Eii,        750 ] (75.00%)
+// INDEXED-NEXT:         [  1, _ZN8Derived15func2Eii,        250 ] (25.00%)
+// INDEXED-NEXT:     VTable Results:
+// INDEXED-NEXT:         [  0, {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E,        750 ] (75.00%)
+// INDEXED-NEXT:         [  0, _ZTV8Derived1,        250 ] (25.00%)
+// INDEXED-NEXT:         [  1, {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E,        750 ] (75.00%)
+// INDEXED-NEXT:         [  1, _ZTV8Derived1,        250 ] (25.00%)
+// COMMON: Instrumentation level: IR  entry_first = 0
+// COMMON-NEXT: Functions shown: 1
+// COMMON-NEXT: Total functions: 6
+// COMMON-NEXT: Maximum function count: 1000
+// COMMON-NEXT: Maximum internal block count: 250
+// COMMON-NEXT: Statistics for indirect call sites profile:
+// COMMON-NEXT:   Total number of sites: 2
+// COMMON-NEXT:   Total number of sites with values: 2
+// COMMON-NEXT:   Total number of profiled values: 4
+// COMMON-NEXT:   Value sites histogram:
+// COMMON-NEXT:         NumTargets, SiteCount
+// COMMON-NEXT:         2, 2
+// COMMON-NEXT: Statistics for vtable profile:
+// COMMON-NEXT:   Total number of sites: 2
+// COMMON-NEXT:   Total number of sites with values: 2
+// COMMON-NEXT:   Total number of profiled values: 4
+// COMMON-NEXT:   Value sites histogram:
+// COMMON-NEXT:         NumTargets, SiteCount
+// COMMON-NEXT:         2, 2
+
+// ICTEXT: :ir
+// ICTEXT: main
+// ICTEXT: # Func Hash:
+// ICTEXT: 1124236338992350536
+// ICTEXT: # Num Counters:
+// ICTEXT: 2
+// ICTEXT: # Counter Values:
+// ICTEXT: 1000
+// ICTEXT: 1
+// ICTEXT: # Num Value Kinds:
+// ICTEXT: 2
+// ICTEXT: # ValueKind = IPVK_IndirectCallTarget:
+// ICTEXT: 0
+// ICTEXT: # NumValueSites:
+// ICTEXT: 2
+// ICTEXT: 2
+// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func1Eii:750
+// ICTEXT: _ZN8Derived15func1Eii:250
+// ICTEXT: 2
+// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func2Eii:750
+// ICTEXT: _ZN8Derived15func2Eii:250
+// ICTEXT: # ValueKind = IPVK_VTableTarget:
+// ICTEXT: 2
+// ICTEXT: # NumValueSites:
+// ICTEXT: 2
+// ICTEXT: 2
+// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E:750
+// ICTEXT: _ZTV8Derived1:250
+// ICTEXT: 2
+// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E:750
+// ICTEXT: _ZTV8Derived1:250
+
+#include <cstdio>
+#include <cstdlib>
+class Base {
+public:
+  virtual int func1(int a, int b) = 0;
+  virtual int func2(int a, int b) = 0;
+};
+class Derived1 : public Base {
+public:
+  int func1(int a, int b) override { return a + b; }
+
+  int func2(int a, int b) override { return a * b; }
+};
+namespace {
+class Derived2 : public Base {
+public:
+  int func1(int a, int b) override { return a - b; }
+
+  int func2(int a, int b) override { return a * (a - b); }
+};
+} // namespace
+__attribute__((noinline)) Base *createType(int a) {
+  Base *base = nullptr;
+  if (a % 4 == 0)
+    base = new Derived1();
+  else
+    base = new Derived2();
+  return base;
+}
+int main(int argc, char **argv) {
+  int sum = 0;
+  for (int i = 0; i < 1000; i++) {
+    int a = rand();
+    int b = rand();
+    Base *ptr = createType(i);
+    sum += ptr->func1(a, b) + ptr->func2(b, a);
+  }
+  printf("sum is %d\n", sum);
+  return 0;
+}
diff --git a/llvm/include/llvm/Analysis/IndirectCallVisitor.h b/llvm/include/llvm/Analysis/IndirectCallVisitor.h
index 0825e19e..50815f4 100644
--- a/llvm/include/llvm/Analysis/IndirectCallVisitor.h
+++ b/llvm/include/llvm/Analysis/IndirectCallVisitor.h
@@ -16,23 +16,75 @@
 #include <vector>
 
 namespace llvm {
-// Visitor class that finds all indirect call.
+// Visitor class that finds indirect calls or instructions that gives vtable
+// value, depending on Type.
 struct PGOIndirectCallVisitor : public InstVisitor<PGOIndirectCallVisitor> {
+  enum class InstructionType {
+    kIndirectCall = 0,
+    kVTableVal = 1,
+  };
   std::vector<CallBase *> IndirectCalls;
-  PGOIndirectCallVisitor() = default;
+  std::vector<Instruction *> ProfiledAddresses;
+  PGOIndirectCallVisitor(InstructionType Type) : Type(Type) {}
 
   void visitCallBase(CallBase &Call) {
-    if (Call.isIndirectCall())
+    if (!Call.isIndirectCall())
+      return;
+
+    if (Type == InstructionType::kIndirectCall) {
       IndirectCalls.push_back(&Call);
+      return;
+    }
+
+    assert(Type == InstructionType::kVTableVal && "Control flow guaranteed");
+
+    LoadInst *LI = dyn_cast<LoadInst>(Call.getCalledOperand());
+    // The code pattern to look for
+    //
+    // %vtable = load ptr, ptr %b
+    // %vfn = getelementptr inbounds ptr, ptr %vtable, i64 1
+    // %2 = load ptr, ptr %vfn
+    // %call = tail call i32 %2(ptr %b)
+    //
+    // %vtable is the vtable address value to profile, and
+    // %2 is the indirect call target address to profile.
+    if (LI != nullptr) {
+      Value *Ptr = LI->getPointerOperand();
+      Value *VTablePtr = Ptr->stripInBoundsConstantOffsets();
+      // This is a heuristic to find address feeding instructions.
+      // FIXME: Add support in the frontend so LLVM type intrinsics are
+      // emitted without LTO. This way, added intrinsics could filter
+      // non-vtable instructions and reduce instrumentation overhead.
+      // Since a non-vtable profiled address is not within the address
+      // range of vtable objects, it's stored as zero in indexed profiles.
+      // A pass that looks up symbol with an zero hash will (almost) always
+      // find nullptr and skip the actual transformation (e.g., comparison
+      // of symbols). So the performance overhead from non-vtable profiled
+      // address is negligible if exists at all. Comparing loaded address
+      // with symbol address guarantees correctness.
+      if (VTablePtr != nullptr && isa<Instruction>(VTablePtr))
+        ProfiledAddresses.push_back(cast<Instruction>(VTablePtr));
+    }
   }
+
+private:
+  InstructionType Type;
 };
 
-// Helper function that finds all indirect call sites.
 inline std::vector<CallBase *> findIndirectCalls(Function &F) {
-  PGOIndirectCallVisitor ICV;
+  PGOIndirectCallVisitor ICV(
+      PGOIndirectCallVisitor::InstructionType::kIndirectCall);
   ICV.visit(F);
   return ICV.IndirectCalls;
 }
+
+inline std::vector<Instruction *> findVTableAddrs(Function &F) {
+  PGOIndirectCallVisitor ICV(
+      PGOIndirectCallVisitor::InstructionType::kVTableVal);
+  ICV.visit(F);
+  return ICV.ProfiledAddresses;
+}
+
 } // namespace llvm
 
 #endif
diff --git a/llvm/include/llvm/ProfileData/InstrProf.h b/llvm/include/llvm/ProfileData/InstrProf.h
index 3a71c02..fd66c4e 100644
--- a/llvm/include/llvm/ProfileData/InstrProf.h
+++ b/llvm/include/llvm/ProfileData/InstrProf.h
@@ -17,6 +17,7 @@
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitmaskEnum.h"
+#include "llvm/ADT/IntervalMap.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
@@ -89,6 +90,9 @@ inline StringRef getInstrProfValueProfMemOpFuncName() {
 /// Return the name prefix of variables containing instrumented function names.
 inline StringRef getInstrProfNameVarPrefix() { return "__profn_"; }
 
+/// Return the name prefix of variables containing virtual table profile data.
+inline StringRef getInstrProfVTableVarPrefix() { return "__profvt_"; }
+
 /// Return the name prefix of variables containing per-function control data.
 inline StringRef getInstrProfDataVarPrefix() { return "__profd_"; }
 
@@ -106,9 +110,9 @@ inline StringRef getInstrProfVNodesVarName() { return "__llvm_prf_vnodes"; }
 
 /// Return the name of the variable holding the strings (possibly compressed)
 /// of all function's PGO names.
-inline StringRef getInstrProfNamesVarName() {
-  return "__llvm_prf_nm";
-}
+inline StringRef getInstrProfNamesVarName() { return "__llvm_prf_nm"; }
+
+inline StringRef getInstrProfVTableNamesVarName() { return "__llvm_prf_vnm"; }
 
 /// Return the name of a covarage mapping variable (internal linkage)
 /// for each instrumented source module. Such variables are allocated
@@ -140,7 +144,8 @@ inline StringRef getInstrProfRegFuncName() {
   return "__llvm_profile_register_function";
 }
 
-/// Return the name of the runtime interface that registers the PGO name strings.
+/// Return the name of the runtime interface that registers the PGO name
+/// strings.
 inline StringRef getInstrProfNamesRegFuncName() {
   return "__llvm_profile_register_names_function";
 }
@@ -246,6 +251,9 @@ Error collectGlobalObjectNameStrings(ArrayRef<std::string> NameStrs,
 Error collectPGOFuncNameStrings(ArrayRef<GlobalVariable *> NameVars,
                                 std::string &Result, bool doCompression = true);
 
+Error collectVTableStrings(ArrayRef<GlobalVariable *> VTables,
+                           std::string &Result, bool doCompression);
+
 /// Check if INSTR_PROF_RAW_VERSION_VAR is defined. This global is only being
 /// set in IR PGO compilation.
 bool isIRPGOFlagSet(const Module *M);
@@ -288,6 +296,8 @@ inline StringRef getPGOFuncNameMetadataName() { return "PGOFuncName"; }
 /// Return the PGOFuncName meta data associated with a function.
 MDNode *getPGOFuncNameMetadata(const Function &F);
 
+std::string getPGOName(const GlobalVariable &V, bool InLTO = false);
+
 /// Create the PGOFuncName meta data if PGOFuncName is different from
 /// function's raw name. This should only apply to internal linkage functions
 /// declared by users only.
@@ -295,7 +305,7 @@ void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName);
 
 /// Check if we can use Comdat for profile variables. This will eliminate
 /// the duplicated profile variables for Comdat functions.
-bool needsComdatForCounter(const Function &F, const Module &M);
+bool needsComdatForCounter(const GlobalObject &GV, const Module &M);
 
 /// An enum describing the attributes of an instrumented profile.
 enum class InstrProfKind {
@@ -431,23 +441,34 @@ public:
   using AddrHashMap = std::vector<std::pair<uint64_t, uint64_t>>;
 
 private:
+  using AddrIntervalMap =
+      IntervalMap<uint64_t, uint64_t, 4, IntervalMapHalfOpenInfo<uint64_t>>;
   StringRef Data;
   uint64_t Address = 0;
-  // Unique name strings.
+  // Unique name strings. Used to ensure entries in MD5NameMap (a vector that's
+  // going to be sorted) has unique MD5 keys in the first place.
   StringSet<> NameTab;
+  // Records the unique virtual table names. This is used by InstrProfWriter to
+  // write out an on-disk chained hash table of virtual table names.
+  // InstrProfWriter stores per function profile data (keyed by function names)
+  // so it doesn't use a StringSet for function names.
+  StringSet<> VTableNames;
   // A map from MD5 keys to function name strings.
   std::vector<std::pair<uint64_t, StringRef>> MD5NameMap;
+
   // A map from MD5 keys to function define. We only populate this map
   // when build the Symtab from a Module.
   std::vector<std::pair<uint64_t, Function *>> MD5FuncMap;
   // A map from function runtime address to function name MD5 hash.
   // This map is only populated and used by raw instr profile reader.
   AddrHashMap AddrToMD5Map;
+
+  AddrIntervalMap::Allocator VTableAddrMapAllocator;
+  // This map is only populated and used by raw instr profile reader.
+  AddrIntervalMap VTableAddrMap;
   bool Sorted = false;
 
-  static StringRef getExternalSymbol() {
-    return "** External Symbol **";
-  }
+  static StringRef getExternalSymbol() { return "** External Symbol **"; }
 
   // Returns the canonial name of the given PGOName. In a canonical name, all
   // suffixes that begins with "." except ".__uniq." are stripped.
@@ -469,7 +490,7 @@ private:
   inline void finalizeSymtab();
 
 public:
-  InstrProfSymtab() = default;
+  InstrProfSymtab() : VTableAddrMap(VTableAddrMapAllocator) {}
 
   // Not copyable or movable.
   // Consider std::unique_ptr for move.
@@ -488,9 +509,19 @@ public:
 
   /// \c NameStrings is a string composed of one of more sub-strings
   ///  encoded in the format described in \c collectPGOFuncNameStrings.
-  /// This method is a wrapper to \c readPGOFuncNameStrings method.
+  /// This method is a wrapper to \c readAndDecodeStrings method.
   Error create(StringRef NameStrings);
 
+  /// Initialize symtab states with function names and vtable names. \c
+  /// FuncNameStrings is a string composed of one or more encoded function name
+  /// strings, and \c VTableNameStrings composes of one or more encoded vtable
+  /// names. This interface is solely used by raw profile reader.
+  Error create(StringRef FuncNameStrings, StringRef VTableNameStrings);
+
+  /// Initialize 'this' with the set of vtable names encoded in
+  /// \c CompressedVTableNames.
+  Error initVTableNamesFromCompressedStrings(StringRef CompressedVTableNames);
+
   /// This interface is used by reader of CoverageMapping test
   /// format.
   inline Error create(StringRef D, uint64_t BaseAddr);
@@ -503,32 +534,69 @@ public:
 
   /// Create InstrProfSymtab from a set of names iteratable from
   /// \p IterRange. This interface is used by IndexedProfReader.
-  template <typename NameIterRange> Error create(const NameIterRange &IterRange);
-
-  /// Update the symtab by adding \p FuncName to the table. This interface
-  /// is used by the raw and text profile readers.
-  Error addFuncName(StringRef FuncName) {
-    if (FuncName.empty())
+  template <typename NameIterRange>
+  Error create(const NameIterRange &IterRange);
+
+  /// Create InstrProfSymtab from a set of function names and vtable
+  /// names iteratable from \p IterRange. This interface is used by
+  /// IndexedProfReader.
+  template <typename FuncNameIterRange, typename VTableNameIterRange>
+  Error create(const FuncNameIterRange &FuncIterRange,
+               const VTableNameIterRange &VTableIterRange);
+
+  Error addSymbolName(StringRef SymbolName) {
+    if (SymbolName.empty())
       return make_error<InstrProfError>(instrprof_error::malformed,
-                                        "function name is empty");
-    auto Ins = NameTab.insert(FuncName);
+                                        "symbol name is empty");
+
+    // Insert into NameTab so that MD5NameMap (a vector that will be sorted)
+    // won't have duplicated entries in the first place.
+    auto Ins = NameTab.insert(SymbolName);
     if (Ins.second) {
       MD5NameMap.push_back(std::make_pair(
-          IndexedInstrProf::ComputeHash(FuncName), Ins.first->getKey()));
+          IndexedInstrProf::ComputeHash(SymbolName), Ins.first->getKey()));
       Sorted = false;
     }
     return Error::success();
   }
 
+  /// The method name is kept since there are many callers.
+  /// It just forwards to 'addSymbolName'.
+  Error addFuncName(StringRef FuncName) { return addSymbolName(FuncName); }
+
+  /// Adds VTableName as a known symbol, and inserts it to a map that
+  /// tracks all vtable names.
+  Error addVTableName(StringRef VTableName) {
+    if (Error E = addSymbolName(VTableName))
+      return E;
+
+    // Record VTableName. InstrProfWriter uses this set. The comment around
+    // class member explains why.
+    VTableNames.insert(VTableName);
+    return Error::success();
+  }
+
+  const StringSet<> &getVTableNames() const { return VTableNames; }
+
   /// Map a function address to its name's MD5 hash. This interface
   /// is only used by the raw profiler reader.
   void mapAddress(uint64_t Addr, uint64_t MD5Val) {
     AddrToMD5Map.push_back(std::make_pair(Addr, MD5Val));
   }
 
+  /// Map the address range (i.e., [start_address, end_address)) of a variable
+  /// to  its names' MD5 hash. This interface is only used by the raw profile
+  /// reader.
+  void mapVTableAddress(uint64_t StartAddr, uint64_t EndAddr, uint64_t MD5Val) {
+    VTableAddrMap.insert(StartAddr, EndAddr, MD5Val);
+  }
+
   /// Return a function's hash, or 0, if the function isn't in this SymTab.
   uint64_t getFunctionHashFromAddress(uint64_t Address);
 
+  /// Return a vtable's hash, or 0 if the vtable doesn't exist in this SymTab.
+  uint64_t getVTableHashFromAddress(uint64_t Address);
+
   /// Return function's PGO name from the function name's symbol
   /// address in the object file. If an error occurs, return
   /// an empty string.
@@ -574,6 +642,24 @@ Error InstrProfSymtab::create(const NameIterRange &IterRange) {
   return Error::success();
 }
 
+template <typename FuncNameIterRange, typename VTableNameIterRange>
+Error InstrProfSymtab::create(const FuncNameIterRange &FuncIterRange,
+                              const VTableNameIterRange &VTableIterRange) {
+  // Iterate elements by StringRef rather than by const reference.
+  // StringRef is small enough, so the loop is efficient whether
+  // element in the range is std::string or StringRef.
+  for (StringRef Name : FuncIterRange)
+    if (Error E = addFuncName(Name))
+      return E;
+
+  for (StringRef VTableName : VTableIterRange)
+    if (Error E = addVTableName(VTableName))
+      return E;
+
+  finalizeSymtab();
+  return Error::success();
+}
+
 void InstrProfSymtab::finalizeSymtab() {
   if (Sorted)
     return;
@@ -877,6 +963,8 @@ private:
       return ValueData->IndirectCallSites;
     case IPVK_MemOPSize:
       return ValueData->MemOPSizes;
+    case IPVK_VTableTarget:
+      return ValueData->VTableTargets;
     default:
       llvm_unreachable("Unknown value kind!");
     }
diff --git a/llvm/include/llvm/ProfileData/InstrProfReader.h b/llvm/include/llvm/ProfileData/InstrProfReader.h
index cfde5d3..e46570a 100644
--- a/llvm/include/llvm/ProfileData/InstrProfReader.h
+++ b/llvm/include/llvm/ProfileData/InstrProfReader.h
@@ -626,6 +626,12 @@ public:
   InstrProfKind getProfileKind() const override;
 
   Error populateSymtab(InstrProfSymtab &Symtab) override {
+    // FIXME: the create method calls 'finalizeSymtab' and sorts a bunch of
+    // arrays/maps. Since there are other data sources other than 'HashTable' to
+    // populate a symtab, it might make sense to have something like this
+    // 1. Let each data source populate Symtab and init the arrays/maps without
+    // calling 'finalizeSymtab'
+    // 2. Call 'finalizeSymtab' once to get all arrays/maps sorted if needed.
     return Symtab.create(HashTable->keys());
   }
 };
diff --git a/llvm/include/llvm/ProfileData/InstrProfWriter.h b/llvm/include/llvm/ProfileData/InstrProfWriter.h
index d2156c8..4b42392 100644
--- a/llvm/include/llvm/ProfileData/InstrProfWriter.h
+++ b/llvm/include/llvm/ProfileData/InstrProfWriter.h
@@ -63,6 +63,9 @@ private:
   // List of binary ids.
   std::vector<llvm::object::BuildID> BinaryIds;
 
+  // Read the vtable names from raw instr profile reader.
+  StringSet<> VTableNames;
+
   // An enum describing the attributes of the profile.
   InstrProfKind ProfileKind = InstrProfKind::Unknown;
   // Use raw pointer here for the incomplete type object.
@@ -95,6 +98,7 @@ public:
   void addRecord(NamedInstrProfRecord &&I, function_ref<void(Error)> Warn) {
     addRecord(std::move(I), 1, Warn);
   }
+  void addVTableName(StringRef VTableName) { VTableNames.insert(VTableName); }
 
   /// Add \p SrcTraces using reservoir sampling where \p SrcStreamSize is the
   /// total number of temporal profiling traces the source has seen.
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 8cf97fc..90c3cfc 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -34,6 +34,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Compression.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -57,6 +58,8 @@
 
 using namespace llvm;
 
+#define DEBUG_TYPE "instrprof"
+
 static cl::opt<bool> StaticFuncFullModulePrefix(
     "static-func-full-module-prefix", cl::init(true), cl::Hidden,
     cl::desc("Use full module build paths in the profile counter names for "
@@ -219,6 +222,12 @@ cl::opt<bool> DoInstrProfNameCompression(
     "enable-name-compression",
     cl::desc("Enable name/filename string compression"), cl::init(true));
 
+cl::opt<bool> EnableVTableValueProfiling(
+    "enable-vtable-value-profiling", cl::init(false),
+    cl::desc("If true, the virtual table address will be instrumented to know "
+             "the types of a C++ pointer. The information is used in indirect "
+             "call promotion to do selective vtable-based comparison."));
+
 std::string getInstrProfSectionName(InstrProfSectKind IPSK,
                                     Triple::ObjectFormatType OF,
                                     bool AddSegmentInfo) {
@@ -378,6 +387,13 @@ std::string getPGOFuncName(const Function &F, bool InLTO, uint64_t Version) {
   return getPGOFuncName(F.getName(), GlobalValue::ExternalLinkage, "");
 }
 
+std::string getPGOName(const GlobalVariable &V, bool InLTO) {
+  // PGONameMetadata should be set by compiler at profile use time
+  // and read by symtab creation to look up symbols corresponding to
+  // a MD5 hash.
+  return getIRPGOObjectName(V, InLTO, /*PGONameMetadata=*/nullptr);
+}
+
 // See getIRPGOObjectName() for a discription of the format.
 std::pair<StringRef, StringRef> getParsedIRPGOName(StringRef IRPGOName) {
   auto [FileName, MangledName] = IRPGOName.split(kGlobalIdentifierDelimiter);
@@ -459,6 +475,7 @@ Error InstrProfSymtab::create(Module &M, bool InLTO) {
     if (Error E = addFuncWithName(F, getPGOFuncName(F, InLTO)))
       return E;
   }
+
   Sorted = false;
   finalizeSymtab();
   return Error::success();
@@ -517,6 +534,25 @@ Error InstrProfSymtab::create(StringRef NameStrings) {
       std::bind(&InstrProfSymtab::addFuncName, this, std::placeholders::_1));
 }
 
+Error InstrProfSymtab::create(StringRef FuncNameStrings,
+                              StringRef VTableNameStrings) {
+  if (Error E = readAndDecodeStrings(FuncNameStrings,
+                                     std::bind(&InstrProfSymtab::addFuncName,
+                                               this, std::placeholders::_1)))
+    return E;
+
+  return readAndDecodeStrings(
+      VTableNameStrings,
+      std::bind(&InstrProfSymtab::addVTableName, this, std::placeholders::_1));
+}
+
+Error InstrProfSymtab::initVTableNamesFromCompressedStrings(
+    StringRef CompressedVTableStrings) {
+  return readAndDecodeStrings(
+      CompressedVTableStrings,
+      std::bind(&InstrProfSymtab::addVTableName, this, std::placeholders::_1));
+}
+
 StringRef InstrProfSymtab::getCanonicalName(StringRef PGOName) {
   // In ThinLTO, local function may have been promoted to global and have
   // suffix ".llvm." added to the function name. We need to add the
@@ -560,6 +596,12 @@ Error InstrProfSymtab::addFuncWithName(Function &F, StringRef PGOFuncName) {
   return Error::success();
 }
 
+uint64_t InstrProfSymtab::getVTableHashFromAddress(uint64_t Address) {
+  // Given a runtime address, look up the hash value in the interval map, and
+  // fallback to value 0 if a hash value is not found.
+  return VTableAddrMap.lookup(Address, 0);
+}
+
 uint64_t InstrProfSymtab::getFunctionHashFromAddress(uint64_t Address) {
   finalizeSymtab();
   auto It = partition_point(AddrToMD5Map, [=](std::pair<uint64_t, uint64_t> A) {
@@ -636,6 +678,16 @@ Error collectPGOFuncNameStrings(ArrayRef<GlobalVariable *> NameVars,
       NameStrs, compression::zlib::isAvailable() && doCompression, Result);
 }
 
+Error collectVTableStrings(ArrayRef<GlobalVariable *> VTables,
+                           std::string &Result, bool doCompression) {
+  std::vector<std::string> VTableNameStrs;
+  for (auto *VTable : VTables)
+    VTableNameStrs.push_back(getPGOName(*VTable));
+  return collectGlobalObjectNameStrings(
+      VTableNameStrs, compression::zlib::isAvailable() && doCompression,
+      Result);
+}
+
 void InstrProfRecord::accumulateCounts(CountSumOrPercent &Sum) const {
   uint64_t FuncSum = 0;
   Sum.NumEntries += Counts.size();
@@ -898,6 +950,9 @@ uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
   if (ValueKind == IPVK_IndirectCallTarget)
     return SymTab->getFunctionHashFromAddress(Value);
 
+  if (ValueKind == IPVK_VTableTarget)
+    return SymTab->getVTableHashFromAddress(Value);
+
   return Value;
 }
 
@@ -1288,8 +1343,8 @@ void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName) {
   F.setMetadata(getPGOFuncNameMetadataName(), N);
 }
 
-bool needsComdatForCounter(const Function &F, const Module &M) {
-  if (F.hasComdat())
+bool needsComdatForCounter(const GlobalObject &GO, const Module &M) {
+  if (GO.hasComdat())
     return true;
 
   if (!Triple(M.getTargetTriple()).supportsCOMDAT())
@@ -1305,7 +1360,7 @@ bool needsComdatForCounter(const Function &F, const Module &M) {
   // available_externally functions will end up being duplicated in raw profile
   // data. This can result in distorted profile as the counts of those dups
   // will be accumulated by the profile merger.
-  GlobalValue::LinkageTypes Linkage = F.getLinkage();
+  GlobalValue::LinkageTypes Linkage = GO.getLinkage();
   if (Linkage != GlobalValue::ExternalWeakLinkage &&
       Linkage != GlobalValue::AvailableExternallyLinkage)
     return false;
@@ -1461,7 +1516,7 @@ void OverlapStats::dump(raw_fd_ostream &OS) const {
   for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
     if (Base.ValueCounts[I] < 1.0f && Test.ValueCounts[I] < 1.0f)
       continue;
-    char ProfileKindName[20];
+    char ProfileKindName[20] = {0};
     switch (I) {
     case IPVK_IndirectCallTarget:
       strncpy(ProfileKindName, "IndirectCall", 19);
@@ -1469,6 +1524,9 @@ void OverlapStats::dump(raw_fd_ostream &OS) const {
     case IPVK_MemOPSize:
       strncpy(ProfileKindName, "MemOP", 19);
       break;
+    case IPVK_VTableTarget:
+      strncpy(ProfileKindName, "VTable", 19);
+      break;
     default:
       snprintf(ProfileKindName, 19, "VP[%d]", I);
       break;
diff --git a/llvm/lib/ProfileData/InstrProfReader.cpp b/llvm/lib/ProfileData/InstrProfReader.cpp
index a275d48..7ac5c56 100644
--- a/llvm/lib/ProfileData/InstrProfReader.cpp
+++ b/llvm/lib/ProfileData/InstrProfReader.cpp
@@ -370,8 +370,11 @@ TextInstrProfReader::readValueProfileData(InstrProfRecord &Record) {
         } else if (ValueKind == IPVK_VTableTarget) {
           if (InstrProfSymtab::isExternalSymbol(VD.first))
             Value = 0;
-          else
+          else {
+            if (Error E = Symtab->addVTableName(VD.first))
+              return E;
             Value = IndexedInstrProf::ComputeHash(VD.first);
+          }
         } else {
           READ_NUM(VD.first, Value);
         }
@@ -539,7 +542,8 @@ Error RawInstrProfReader<IntPtrT>::readNextHeader(const char *CurrentPos) {
 
 template <class IntPtrT>
 Error RawInstrProfReader<IntPtrT>::createSymtab(InstrProfSymtab &Symtab) {
-  if (Error E = Symtab.create(StringRef(NamesStart, NamesEnd - NamesStart)))
+  if (Error E = Symtab.create(StringRef(NamesStart, NamesEnd - NamesStart),
+                              StringRef(VNamesStart, VNamesEnd - VNamesStart)))
     return error(std::move(E));
   for (const RawInstrProf::ProfileData<IntPtrT> *I = Data; I != DataEnd; ++I) {
     const IntPtrT FPtr = swap(I->FunctionPointer);
@@ -547,6 +551,21 @@ Error RawInstrProfReader<IntPtrT>::createSymtab(InstrProfSymtab &Symtab) {
       continue;
     Symtab.mapAddress(FPtr, swap(I->NameRef));
   }
+
+  if (VTableBegin != nullptr && VTableEnd != nullptr) {
+    for (const RawInstrProf::VTableProfileData<IntPtrT> *I = VTableBegin;
+         I != VTableEnd; ++I) {
+      const IntPtrT VPtr = swap(I->VTablePointer);
+      if (!VPtr)
+        continue;
+      // Map both begin and end address to the name hash, since the instrumented
+      // address could be somewhere in the middle.
+      // VPtr is of type uint32_t or uint64_t so 'VPtr + I->VTableSize' marks
+      // the end of vtable address.
+      Symtab.mapVTableAddress(VPtr, VPtr + swap(I->VTableSize),
+                              swap(I->VTableNameHash));
+    }
+  }
   return success();
 }
 
@@ -1397,7 +1416,15 @@ InstrProfSymtab &IndexedInstrProfReader::getSymtab() {
   if (Symtab)
     return *Symtab;
 
-  std::unique_ptr<InstrProfSymtab> NewSymtab = std::make_unique<InstrProfSymtab>();
+  auto NewSymtab = std::make_unique<InstrProfSymtab>();
+
+  if (Error E = NewSymtab->initVTableNamesFromCompressedStrings(
+          StringRef(VTableNamePtr, CompressedVTableNamesLen))) {
+    auto [ErrCode, Msg] = InstrProfError::take(std::move(E));
+    consumeError(error(ErrCode, Msg));
+  }
+
+  // finalizeSymtab is called inside populateSymtab.
   if (Error E = Index->populateSymtab(*NewSymtab)) {
     auto [ErrCode, Msg] = InstrProfError::take(std::move(E));
     consumeError(error(ErrCode, Msg));
diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
index 8f067f8..c2c94ba 100644
--- a/llvm/lib/ProfileData/InstrProfWriter.cpp
+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/ProfileData/MemProf.h"
 #include "llvm/ProfileData/ProfileCommon.h"
+#include "llvm/Support/Compression.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/EndianStream.h"
 #include "llvm/Support/Error.h"
@@ -636,13 +637,18 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
   uint64_t VTableNamesSectionStart = OS.tell();
 
   if (!WritePrevVersion) {
-    // Use a dummy (and uncompressed) string as compressed vtable names and get
-    // the necessary profile format change in place for version 12.
-    // TODO: Store the list of vtable names in InstrProfWriter and use the
-    // real compressed name.
-    std::string CompressedVTableNames = "VTableNames";
+    std::vector<std::string> VTableNameStrs;
+    for (StringRef VTableName : VTableNames.keys())
+      VTableNameStrs.push_back(VTableName.str());
+
+    std::string CompressedVTableNames;
+    if (!VTableNameStrs.empty())
+      if (Error E = collectGlobalObjectNameStrings(
+              VTableNameStrs, compression::zlib::isAvailable(),
+              CompressedVTableNames))
+        return E;
 
-    uint64_t CompressedStringLen = CompressedVTableNames.length();
+    const uint64_t CompressedStringLen = CompressedVTableNames.length();
 
     // Record the length of compressed string.
     OS.write(CompressedStringLen);
@@ -652,12 +658,11 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
       OS.writeByte(static_cast<uint8_t>(c));
 
     // Pad up to a multiple of 8.
-    // InstrProfReader would read bytes according to 'CompressedStringLen'.
-    uint64_t PaddedLength = alignTo(CompressedStringLen, 8);
+    // InstrProfReader could read bytes according to 'CompressedStringLen'.
+    const uint64_t PaddedLength = alignTo(CompressedStringLen, 8);
 
-    for (uint64_t K = CompressedStringLen; K < PaddedLength; K++) {
+    for (uint64_t K = CompressedStringLen; K < PaddedLength; K++)
       OS.writeByte(0);
-    }
   }
 
   uint64_t TemporalProfTracesSectionStart = 0;
@@ -866,6 +871,10 @@ Error InstrProfWriter::writeText(raw_fd_ostream &OS) {
     }
   }
 
+  for (const auto &VTableName : VTableNames)
+    if (Error E = Symtab.addVTableName(VTableName.getKey()))
+      return E;
+
   if (static_cast<bool>(ProfileKind & InstrProfKind::TemporalProfile))
     writeTextTemporalProfTraceData(OS, Symtab);
 
diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
index c42c53e..f9b58d9 100644
--- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -64,6 +64,9 @@ using namespace llvm;
 #define DEBUG_TYPE "instrprof"
 
 namespace llvm {
+// Command line option to enable vtable value profiling. Defined in
+// ProfileData/InstrProf.cpp: -enable-vtable-value-profiling=
+extern cl::opt<bool> EnableVTableValueProfiling;
 // TODO: Remove -debug-info-correlate in next LLVM release, in favor of
 // -profile-correlate=debug-info.
 cl::opt<bool> DebugInfoCorrelate(
@@ -219,12 +222,18 @@ private:
     PerFunctionProfileData() = default;
   };
   DenseMap<GlobalVariable *, PerFunctionProfileData> ProfileDataMap;
+  // Key is virtual table variable, value is 'VTableProfData' in the form of
+  // GlobalVariable.
+  DenseMap<GlobalVariable *, GlobalVariable *> VTableDataMap;
   /// If runtime relocation is enabled, this maps functions to the load
   /// instruction that produces the profile relocation bias.
   DenseMap<const Function *, LoadInst *> FunctionToProfileBiasMap;
   std::vector<GlobalValue *> CompilerUsedVars;
   std::vector<GlobalValue *> UsedVars;
   std::vector<GlobalVariable *> ReferencedNames;
+  // The list of virtual table variables of which the VTableProfData is
+  // collected.
+  std::vector<GlobalVariable *> ReferencedVTables;
   GlobalVariable *NamesVar = nullptr;
   size_t NamesSize = 0;
 
@@ -308,7 +317,7 @@ private:
                                       GlobalValue::LinkageTypes Linkage);
 
   /// Set Comdat property of GV, if required.
-  void maybeSetComdat(GlobalVariable *GV, Function *Fn, StringRef VarName);
+  void maybeSetComdat(GlobalVariable *GV, GlobalObject *GO, StringRef VarName);
 
   /// Setup the sections into which counters and bitmaps are allocated.
   GlobalVariable *setupProfileSection(InstrProfInstBase *Inc,
@@ -317,9 +326,15 @@ private:
   /// Create INSTR_PROF_DATA variable for counters and bitmaps.
   void createDataVariable(InstrProfCntrInstBase *Inc);
 
+  /// Get the counters for virtual table values, creating them if necessary.
+  void getOrCreateVTableProfData(GlobalVariable *GV);
+
   /// Emit the section with compressed function names.
   void emitNameData();
 
+  /// Emit the section with compressed vtable names.
+  void emitVTableNames();
+
   /// Emit value nodes section for value profiling.
   void emitVNodes();
 
@@ -763,6 +778,12 @@ bool InstrLowerer::lower() {
     }
   }
 
+  if (EnableVTableValueProfiling)
+    for (GlobalVariable &GV : M.globals())
+      // Global variables with type metadata are virtual table variables.
+      if (GV.hasMetadata(LLVMContext::MD_type))
+        getOrCreateVTableProfData(&GV);
+
   for (Function &F : M)
     MadeChange |= lowerIntrinsics(&F);
 
@@ -776,6 +797,7 @@ bool InstrLowerer::lower() {
 
   emitVNodes();
   emitNameData();
+  emitVTableNames();
 
   // Emit runtime hook for the cases where the target does not unconditionally
   // require pulling in profile runtime, and coverage is enabled on code that is
@@ -1193,13 +1215,13 @@ static bool needsRuntimeRegistrationOfSectionRange(const Triple &TT) {
   return true;
 }
 
-void InstrLowerer::maybeSetComdat(GlobalVariable *GV, Function *Fn,
+void InstrLowerer::maybeSetComdat(GlobalVariable *GV, GlobalObject *GO,
                                   StringRef CounterGroupName) {
   // Place lowered global variables in a comdat group if the associated function
-  // is a COMDAT. This will make sure that only one copy of global variable
-  // (e.g. function counters) of the COMDAT function will be emitted after
-  // linking.
-  bool NeedComdat = needsComdatForCounter(*Fn, M);
+  // or global variable is a COMDAT. This will make sure that only one copy of
+  // global variable (e.g. function counters) of the COMDAT function will be
+  // emitted after linking.
+  bool NeedComdat = needsComdatForCounter(*GO, M);
   bool UseComdat = (NeedComdat || TT.isOSBinFormatELF());
 
   if (!UseComdat)
@@ -1237,6 +1259,104 @@ void InstrLowerer::maybeSetComdat(GlobalVariable *GV, Function *Fn,
     GV->setLinkage(GlobalValue::InternalLinkage);
 }
 
+static inline bool shouldRecordVTableAddr(GlobalVariable *GV) {
+  if (!profDataReferencedByCode(*GV->getParent()))
+    return false;
+
+  if (!GV->hasLinkOnceLinkage() && !GV->hasLocalLinkage() &&
+      !GV->hasAvailableExternallyLinkage())
+    return true;
+
+  // This avoids the profile data from referencing internal symbols in
+  // COMDAT.
+  if (GV->hasLocalLinkage() && GV->hasComdat())
+    return false;
+
+  return true;
+}
+
+// FIXME: Introduce an internal alias like what's done for functions to reduce
+// the number of relocation entries.
+static inline Constant *getVTableAddrForProfData(GlobalVariable *GV) {
+  auto *Int8PtrTy = PointerType::getUnqual(GV->getContext());
+
+  // Store a nullptr in __profvt_ if a real address shouldn't be used.
+  if (!shouldRecordVTableAddr(GV))
+    return ConstantPointerNull::get(Int8PtrTy);
+
+  return ConstantExpr::getBitCast(GV, Int8PtrTy);
+}
+
+void InstrLowerer::getOrCreateVTableProfData(GlobalVariable *GV) {
+  assert(!DebugInfoCorrelate &&
+         "Value profiling is not supported with lightweight instrumentation");
+  if (GV->isDeclaration() || GV->hasAvailableExternallyLinkage())
+    return;
+
+  // Skip llvm internal global variable or __prof variables.
+  if (GV->getName().starts_with("llvm.") ||
+      GV->getName().starts_with("__llvm") ||
+      GV->getName().starts_with("__prof"))
+    return;
+
+  // VTableProfData already created
+  auto It = VTableDataMap.find(GV);
+  if (It != VTableDataMap.end() && It->second)
+    return;
+
+  GlobalValue::LinkageTypes Linkage = GV->getLinkage();
+  GlobalValue::VisibilityTypes Visibility = GV->getVisibility();
+
+  // This is to keep consistent with per-function profile data
+  // for correctness.
+  if (TT.isOSBinFormatXCOFF()) {
+    Linkage = GlobalValue::InternalLinkage;
+    Visibility = GlobalValue::DefaultVisibility;
+  }
+
+  LLVMContext &Ctx = M.getContext();
+  Type *DataTypes[] = {
+#define INSTR_PROF_VTABLE_DATA(Type, LLVMType, Name, Init) LLVMType,
+#include "llvm/ProfileData/InstrProfData.inc"
+#undef INSTR_PROF_VTABLE_DATA
+  };
+
+  auto *DataTy = StructType::get(Ctx, ArrayRef(DataTypes));
+
+  // Used by INSTR_PROF_VTABLE_DATA MACRO
+  Constant *VTableAddr = getVTableAddrForProfData(GV);
+  const std::string PGOVTableName = getPGOName(*GV);
+  // Record the length of the vtable. This is needed since vtable pointers
+  // loaded from C++ objects might be from the middle of a vtable definition.
+  uint32_t VTableSizeVal =
+      M.getDataLayout().getTypeAllocSize(GV->getValueType());
+
+  Constant *DataVals[] = {
+#define INSTR_PROF_VTABLE_DATA(Type, LLVMType, Name, Init) Init,
+#include "llvm/ProfileData/InstrProfData.inc"
+#undef INSTR_PROF_VTABLE_DATA
+  };
+
+  auto *Data =
+      new GlobalVariable(M, DataTy, /*constant=*/false, Linkage,
+                         ConstantStruct::get(DataTy, DataVals),
+                         getInstrProfVTableVarPrefix() + PGOVTableName);
+
+  Data->setVisibility(Visibility);
+  Data->setSection(getInstrProfSectionName(IPSK_vtab, TT.getObjectFormat()));
+  Data->setAlignment(Align(8));
+
+  maybeSetComdat(Data, GV, Data->getName());
+
+  VTableDataMap[GV] = Data;
+
+  ReferencedVTables.push_back(GV);
+
+  // VTable <Hash, Addr> is used by runtime but not referenced by other
+  // sections. Conservatively mark it linker retained.
+  UsedVars.push_back(Data);
+}
+
 GlobalVariable *InstrLowerer::setupProfileSection(InstrProfInstBase *Inc,
                                                   InstrProfSectKind IPSK) {
   GlobalVariable *NamePtr = Inc->getName();
@@ -1633,6 +1753,31 @@ void InstrLowerer::emitNameData() {
     NamePtr->eraseFromParent();
 }
 
+void InstrLowerer::emitVTableNames() {
+  if (!EnableVTableValueProfiling || ReferencedVTables.empty())
+    return;
+
+  // Collect the PGO names of referenced vtables and compress them.
+  std::string CompressedVTableNames;
+  if (Error E = collectVTableStrings(ReferencedVTables, CompressedVTableNames,
+                                     DoInstrProfNameCompression)) {
+    report_fatal_error(Twine(toString(std::move(E))), false);
+  }
+
+  auto &Ctx = M.getContext();
+  auto *VTableNamesVal = ConstantDataArray::getString(
+      Ctx, StringRef(CompressedVTableNames), false /* AddNull */);
+  GlobalVariable *VTableNamesVar =
+      new GlobalVariable(M, VTableNamesVal->getType(), true /* constant */,
+                         GlobalValue::PrivateLinkage, VTableNamesVal,
+                         getInstrProfVTableNamesVarName());
+  VTableNamesVar->setSection(
+      getInstrProfSectionName(IPSK_vname, TT.getObjectFormat()));
+  VTableNamesVar->setAlignment(Align(1));
+  // Make VTableNames linker retained.
+  UsedVars.push_back(VTableNamesVar);
+}
+
 void InstrLowerer::emitRegistration() {
   if (!needsRuntimeRegistrationOfSectionRange(TT))
     return;
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
index 50eccc6..98c6f8c 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -327,6 +327,9 @@ extern cl::opt<PGOViewCountsType> PGOViewCounts;
 // Defined in Analysis/BlockFrequencyInfo.cpp:  -view-bfi-func-name=
 extern cl::opt<std::string> ViewBlockFreqFuncName;
 
+// Command line option to enable vtable value profiling. Defined in
+// ProfileData/InstrProf.cpp: -enable-vtable-value-profiling=
+extern cl::opt<bool> EnableVTableValueProfiling;
 extern cl::opt<InstrProfCorrelator::ProfCorrelatorKind> ProfileCorrelate;
 } // namespace llvm
 
@@ -581,6 +584,8 @@ public:
       NumOfPGOMemIntrinsics += ValueSites[IPVK_MemOPSize].size();
       NumOfPGOBB += MST.bbInfoSize();
       ValueSites[IPVK_IndirectCallTarget] = VPC.get(IPVK_IndirectCallTarget);
+      if (EnableVTableValueProfiling)
+        ValueSites[IPVK_VTableTarget] = VPC.get(IPVK_VTableTarget);
     } else {
       NumOfCSPGOSelectInsts += SIVisitor.getNumOfSelectInsts();
       NumOfCSPGOMemIntrinsics += ValueSites[IPVK_MemOPSize].size();
@@ -1775,6 +1780,15 @@ static bool InstrumentAllFunctions(
   // (before LTO/ThinLTO linking) to create these variables.
   if (!IsCS)
     createIRLevelProfileFlagVar(M, /*IsCS=*/false);
+
+  Triple TT(M.getTargetTriple());
+  LLVMContext &Ctx = M.getContext();
+  if (!TT.isOSBinFormatELF() && EnableVTableValueProfiling)
+    Ctx.diagnose(DiagnosticInfoPGOProfile(
+        M.getName().data(),
+        Twine("VTable value profiling is presently not "
+              "supported for non-ELF object formats"),
+        DS_Warning));
   std::unordered_multimap<Comdat *, GlobalValue *> ComdatMembers;
   collectComdatMembers(M, ComdatMembers);
 
diff --git a/llvm/lib/Transforms/Instrumentation/ValueProfilePlugins.inc b/llvm/lib/Transforms/Instrumentation/ValueProfilePlugins.inc
index 3a129de..b47ef85 100644
--- a/llvm/lib/Transforms/Instrumentation/ValueProfilePlugins.inc
+++ b/llvm/lib/Transforms/Instrumentation/ValueProfilePlugins.inc
@@ -90,9 +90,38 @@ public:
   }
 };
 
+///--------------------- VirtualTableValueProfilingPlugin --------------------
+class VTableProfilingPlugin {
+  Function &F;
+
+public:
+  static constexpr InstrProfValueKind Kind = IPVK_VTableTarget;
+
+  VTableProfilingPlugin(Function &Fn, TargetLibraryInfo &TLI) : F(Fn) {}
+
+  void run(std::vector<CandidateInfo> &Candidates) {
+    std::vector<Instruction *> Result = findVTableAddrs(F);
+    for (Instruction *I : Result) {
+      Instruction *InsertPt = I->getNextNonDebugInstruction();
+      // When finding an insertion point, keep PHI and EH pad instructions
+      // before vp intrinsics. This is similar to
+      // `BasicBlock::getFirstInsertionPt`.
+      while (InsertPt && (dyn_cast<PHINode>(InsertPt) || InsertPt->isEHPad()))
+        InsertPt = InsertPt->getNextNonDebugInstruction();
+      // Skip instrumentating the value if InsertPt is the last instruction.
+      // FIXME: Set InsertPt to the end of basic block to instrument the value
+      // if InsertPt is the last instruction.
+      if (InsertPt == nullptr)
+        continue;
+
+      Instruction *AnnotatedInst = I;
+      Candidates.emplace_back(CandidateInfo{I, InsertPt, AnnotatedInst});
+    }
+  }
+};
+
 ///----------------------- Registration of the plugins -------------------------
 /// For now, registering a plugin with the ValueProfileCollector is done by
 /// adding the plugin type to the VP_PLUGIN_LIST macro.
-#define VP_PLUGIN_LIST           \
-    MemIntrinsicPlugin,          \
-    IndirectCallPromotionPlugin
+#define VP_PLUGIN_LIST                                                         \
+  MemIntrinsicPlugin, IndirectCallPromotionPlugin, VTableProfilingPlugin
diff --git a/llvm/test/Transforms/PGOProfile/vtable_prof_unsupported.ll b/llvm/test/Transforms/PGOProfile/vtable_prof_unsupported.ll
new file mode 100644
index 0000000..f72a20f
--- /dev/null
+++ b/llvm/test/Transforms/PGOProfile/vtable_prof_unsupported.ll
@@ -0,0 +1,34 @@
+; RUN: opt < %s -passes=pgo-instr-gen -enable-vtable-value-profiling -S 2>&1 | FileCheck %s
+
+; Test that unsupported warning is emitted for non-ELF object files.
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+target triple = "arm64-apple-macosx14.0.0"
+
+; CHECK: warning: {{.*}} VTable value profiling is presently not supported for non-ELF object formats
+
+@_ZTV4Base = constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN4Base4funcEi] }, !type !0, !type !1
+@_ZTV7Derived = constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN7Derived4funcEi] }, !type !0, !type !1, !type !2, !type !3
+
+@llvm.compiler.used = appending global [2 x ptr] [ptr @_ZTV4Base, ptr @_ZTV7Derived], section "llvm.metadata"
+
+define i32 @_Z4funci(i32 %a) {
+entry:
+  %call = call ptr @_Z10createTypev()
+  %vtable = load ptr, ptr %call
+  %0 = call i1 @llvm.public.type.test(ptr %vtable, metadata !"_ZTS7Derived")
+  call void @llvm.assume(i1 %0)
+  %1 = load ptr, ptr %vtable
+  %call1 = call i32 %1(ptr  %call, i32 %a)
+  ret i32 %call1
+}
+
+declare ptr @_Z10createTypev() 
+declare i1 @llvm.public.type.test(ptr, metadata)
+declare void @llvm.assume(i1)
+declare i32 @_ZN4Base4funcEi(ptr, i32)
+declare i32 @_ZN7Derived4funcEi(ptr , i32)
+
+!0 = !{i64 16, !"_ZTS4Base"}
+!1 = !{i64 16, !"_ZTSM4BaseFiiE.virtual"}
+!2 = !{i64 16, !"_ZTS7Derived"}
+!3 = !{i64 16, !"_ZTSM7DerivedFiiE.virtual"}
diff --git a/llvm/test/Transforms/PGOProfile/vtable_profile.ll b/llvm/test/Transforms/PGOProfile/vtable_profile.ll
new file mode 100644
index 0000000..a844003
--- /dev/null
+++ b/llvm/test/Transforms/PGOProfile/vtable_profile.ll
@@ -0,0 +1,98 @@
+; RUN: opt < %s -passes=pgo-instr-gen -enable-vtable-value-profiling -S 2>&1 | FileCheck %s --check-prefix=GEN --implicit-check-not="VTable value profiling is presently not supported"
+; RUN: opt < %s -passes=pgo-instr-gen,instrprof -enable-vtable-value-profiling -S 2>&1 | FileCheck %s --check-prefix=LOWER --implicit-check-not="VTable value profiling is presently not supported"
+
+; __llvm_prf_vnm stores zlib-compressed vtable names.
+; REQUIRES: zlib
+
+source_filename = "vtable_local.ll"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; The test IR is generated based on the following C++ program.
+; Base1 has external linkage and Base2 has local linkage.
+; class Derived uses multiple inheritance so its virtual table
+; global variable contains two vtables. func1 is loaded from
+; the vtable compatible with class Base1, and func2 is loaded
+; from the vtable compatible with class Base2.
+
+; class Base1 {
+; public:
+;   virtual int func1(int a) ;
+; };
+;
+; namespace {
+; class Base2 {
+; public:
+;   __attribute__((noinline)) virtual int func2(int a) {
+;     return a;
+;   }
+; };
+; }
+
+; class Derived : public Base1, public Base2 {
+; public:
+;   Derived(int c) : v(c) {}
+; private:
+;   int v;
+; };
+;
+; Derived* createType();
+
+; int func(int a) {
+;   Derived* d = createType();
+;   return d->func2(a) + d->func1(a);
+; }
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@_ZTV7Derived = constant { [3 x ptr], [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN5Base15func1Ei], [3 x ptr] [ptr inttoptr (i64 -8 to ptr), ptr null, ptr @_ZN12_GLOBAL__N_15Base25func2Ei] }, !type !0, !type !3, !type !6, !type !8, !type !10
+@_ZTV5Base1 = available_externally constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN5Base15func1Ei] }, !type !0
+@_ZTVN12_GLOBAL__N_15Base2E = internal constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr null, ptr @_ZN12_GLOBAL__N_15Base25func2Ei] }, !type !11, !type !8; !vcall_visibility !12
+@llvm.compiler.used = appending global [1 x ptr] [ptr @_ZTV5Base1], section "llvm.metadata"
+
+; GEN: __llvm_profile_raw_version = comdat any
+; GEN: __llvm_profile_raw_version = hidden constant i64 72057594037927946, comdat
+; GEN: __profn__Z4funci = private constant [8 x i8] c"_Z4funci"
+
+; LOWER: $__profvt__ZTV7Derived = comdat nodeduplicate
+; LOWER: $"__profvt_vtable_local.ll;_ZTVN12_GLOBAL__N_15Base2E" = comdat nodeduplicate
+; LOWER: @__profvt__ZTV7Derived = global { i64, ptr, i32 } { i64 -4576307468236080025, ptr @_ZTV7Derived, i32 48 }, section "__llvm_prf_vtab", comdat, align 8
+; LOWER: @"__profvt_vtable_local.ll;_ZTVN12_GLOBAL__N_15Base2E" = internal global { i64, ptr, i32 } { i64 1419990121885302679, ptr @_ZTVN12_GLOBAL__N_15Base2E, i32 24 }, section "__llvm_prf_vtab", comdat, align 8
+; LOWER: @__llvm_prf_vnm = private constant [64 x i8] c"7>x\DA\8B\8F\0A\093wI-\CA,KMa,+IL\CAI\8D\CF\C9ON\CC\D1\CB\C9\B1\8E\07J\FA\19\1A\C5\BB\FB\F8;9\FA\C4\C7\FB\C5\1B\9A:%\16\A7\1A\B9\02\00\19:\12o", section "__llvm_prf_vns", align 1
+; LOWER: @llvm.used = appending global [5 x ptr] [ptr @__profvt__ZTV7Derived, ptr @"__profvt_vtable_local.ll;_ZTVN12_GLOBAL__N_15Base2E", ptr @__llvm_prf_vnodes, ptr @__llvm_prf_nm, ptr @__llvm_prf_vnm], section "llvm.metadata"
+
+define i32 @_Z4funci(i32 %a) {
+entry:
+  %call = call ptr @_Z10createTypev()
+  %add.ptr = getelementptr inbounds i8, ptr %call, i64 8
+  %vtable = load ptr, ptr %add.ptr
+; GEN: [[P1:%[0-9]+]] = ptrtoint ptr %vtable to i64
+; GEN: call void @llvm.instrprof.value.profile(ptr @__profn__Z4funci, i64 [[CFGHash:[0-9]+]], i64 [[P1]], i32 2, i32 0)
+; LOWER: [[P1:%[0-9]+]] = ptrtoint ptr %vtable to i64
+; LOWER: call void @__llvm_profile_instrument_target(i64 [[P1]], ptr @__profd__Z4funci, i32 2)
+  %vfunc1 = load ptr, ptr %vtable
+  %call1 = call i32 %vfunc1(ptr %add.ptr, i32 %a)
+  %vtable2 = load ptr, ptr %call
+; GEN: [[P2:%[0-9]+]] = ptrtoint ptr %vtable2 to i64
+; GEN: call void @llvm.instrprof.value.profile(ptr @__profn__Z4funci, i64 [[CFGHash]], i64 [[P2]], i32 2, i32 1)
+; LOWER: [[P2:%[0-9]+]] = ptrtoint ptr %vtable2 to i64
+; LOWER: call void @__llvm_profile_instrument_target(i64 [[P2]], ptr @__profd__Z4funci, i32 3)
+  %vfunc2 = load ptr, ptr %vtable2
+  %call4 = call i32 %vfunc2(ptr %call, i32 %a)
+  %add = add nsw i32 %call1, %call4
+  ret i32 %add
+}
+
+declare ptr @_Z10createTypev()
+declare i32 @_ZN12_GLOBAL__N_15Base25func2Ei(ptr %this, i32 %a)
+declare i32 @_ZN5Base15func1Ei(ptr, i32)
+
+!0 = !{i64 16, !"_ZTS5Base1"}
+!3 = !{i64 16, !"_ZTS7Derived"}
+!6 = !{i64 40, !7}
+!7 = distinct !{}
+!8 = !{i64 16, !9}
+!9 = distinct !{}
+!10 = !{i64 40, !9}
+!11 = !{i64 16, !7}
diff --git a/llvm/test/tools/llvm-profdata/Inputs/vtable-value-prof.proftext b/llvm/test/tools/llvm-profdata/Inputs/vtable-value-prof.proftext
new file mode 100644
index 0000000..372f9f97
--- /dev/null
+++ b/llvm/test/tools/llvm-profdata/Inputs/vtable-value-prof.proftext
@@ -0,0 +1,74 @@
+# IR level Instrumentation Flag
+:ir
+_Z10createTypei
+# Func Hash:
+146835647075900052
+# Num Counters:
+2
+# Counter Values:
+750
+250
+
+_ZN8Derived15func1Eii
+# Func Hash:
+742261418966908927
+# Num Counters:
+1
+# Counter Values:
+250
+
+_ZN8Derived15func2Eii
+# Func Hash:
+742261418966908927
+# Num Counters:
+1
+# Counter Values:
+250
+
+main
+# Func Hash:
+1124236338992350536
+# Num Counters:
+2
+# Counter Values:
+1000
+1
+# Num Value Kinds:
+2
+# ValueKind = IPVK_IndirectCallTarget:
+0
+# NumValueSites:
+2
+2
+vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func1Eii:750
+_ZN8Derived15func1Eii:250
+2
+vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func2Eii:750
+_ZN8Derived15func2Eii:250
+# ValueKind = IPVK_VTableTarget:
+2
+# NumValueSites:
+2
+2
+vtable_prof.cc;_ZTVN12_GLOBAL__N_18Derived2E:750
+_ZTV8Derived1:250
+2
+vtable_prof.cc;_ZTVN12_GLOBAL__N_18Derived2E:750
+_ZTV8Derived1:250
+
+vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func1Eii
+# Func Hash:
+742261418966908927
+# Num Counters:
+1
+# Counter Values:
+750
+
+vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func2Eii
+# Func Hash:
+742261418966908927
+# Num Counters:
+1
+# Counter Values:
+750
+
diff --git a/llvm/test/tools/llvm-profdata/vtable-value-prof.test b/llvm/test/tools/llvm-profdata/vtable-value-prof.test
new file mode 100644
index 0000000..378c2e1
--- /dev/null
+++ b/llvm/test/tools/llvm-profdata/vtable-value-prof.test
@@ -0,0 +1,83 @@
+; RUN: rm -rf %t && mkdir %t && cd %t
+
+; Generate indexed profiles from text profiles
+RUN: llvm-profdata merge %S/Inputs/vtable-value-prof.proftext -o indexed.profdata
+
+; Show indexed profiles
+RUN: llvm-profdata show --function=main --ic-targets --show-vtables indexed.profdata | FileCheck %s --check-prefix=INDEXED
+
+; Show text profiles
+RUN: llvm-profdata show --function=main --ic-targets --show-vtables --text %S/Inputs/vtable-value-prof.proftext | FileCheck %s --check-prefix=ICTEXT
+
+; Convert indexed profiles to its textual output and show it.
+RUN: llvm-profdata merge --text -o text-from-indexed.proftext indexed.profdata
+RUN: llvm-profdata show --function=main --ic-targets --show-vtables text-from-indexed.proftext | FileCheck %s --check-prefix=INDEXED
+RUN: llvm-profdata show --function=main --ic-targets --show-vtables --text text-from-indexed.proftext | FileCheck %s --check-prefix=ICTEXT
+
+INDEXED:      Counters:
+INDEXED-NEXT:   main:
+INDEXED-NEXT:     Hash: 0x0f9a16fe6d398548
+INDEXED-NEXT:     Counters: 2
+INDEXED-NEXT:     Indirect Call Site Count: 2
+INDEXED-NEXT:     Number of instrumented vtables: 2
+INDEXED-NEXT:     Indirect Target Results:
+INDEXED-NEXT:         [  0, {{.*}}vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func1Eii,        750 ] (75.00%)
+INDEXED-NEXT:         [  0, _ZN8Derived15func1Eii,        250 ] (25.00%)
+INDEXED-NEXT:         [  1, {{.*}}vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func2Eii,        750 ] (75.00%)
+INDEXED-NEXT:         [  1, _ZN8Derived15func2Eii,        250 ] (25.00%)
+INDEXED-NEXT:     VTable Results:
+INDEXED-NEXT:         [  0, {{.*}}vtable_prof.cc;_ZTVN12_GLOBAL__N_18Derived2E,        750 ] (75.00%)
+INDEXED-NEXT:         [  0, _ZTV8Derived1,        250 ] (25.00%)
+INDEXED-NEXT:         [  1, {{.*}}vtable_prof.cc;_ZTVN12_GLOBAL__N_18Derived2E,        750 ] (75.00%)
+INDEXED-NEXT:         [  1, _ZTV8Derived1,        250 ] (25.00%)
+INDEXED-NEXT: Instrumentation level: IR  entry_first = 0
+INDEXED-NEXT: Functions shown: 1
+INDEXED-NEXT: Total functions: 6
+INDEXED-NEXT: Maximum function count: 1000
+INDEXED-NEXT: Maximum internal block count: 250
+INDEXED-NEXT: Statistics for indirect call sites profile:
+INDEXED-NEXT:   Total number of sites: 2
+INDEXED-NEXT:   Total number of sites with values: 2
+INDEXED-NEXT:   Total number of profiled values: 4
+INDEXED-NEXT:   Value sites histogram:
+INDEXED-NEXT:       NumTargets, SiteCount
+INDEXED-NEXT:       2, 2
+INDEXED-NEXT: Statistics for vtable profile:
+INDEXED-NEXT:   Total number of sites: 2
+INDEXED-NEXT:   Total number of sites with values: 2
+INDEXED-NEXT:   Total number of profiled values: 4
+INDEXED-NEXT:   Value sites histogram:
+INDEXED-NEXT:       NumTargets, SiteCount
+INDEXED-NEXT:       2, 2
+
+ICTEXT: :ir
+ICTEXT: main
+ICTEXT: # Func Hash:
+ICTEXT: 1124236338992350536
+ICTEXT: # Num Counters:
+ICTEXT: 2
+ICTEXT: # Counter Values:
+ICTEXT: 1000
+ICTEXT: 1
+ICTEXT: # Num Value Kinds:
+ICTEXT: 2
+ICTEXT: # ValueKind = IPVK_IndirectCallTarget:
+ICTEXT: 0
+ICTEXT: # NumValueSites:
+ICTEXT: 2
+ICTEXT: 2
+ICTEXT: {{.*}}vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func1Eii:750
+ICTEXT: _ZN8Derived15func1Eii:250
+ICTEXT: 2
+ICTEXT: {{.*}}vtable_prof.cc;_ZN12_GLOBAL__N_18Derived25func2Eii:750
+ICTEXT: _ZN8Derived15func2Eii:250
+ICTEXT: # ValueKind = IPVK_VTableTarget:
+ICTEXT: 2
+ICTEXT: # NumValueSites:
+ICTEXT: 2
+ICTEXT: 2
+ICTEXT: {{.*}}vtable_prof.cc;_ZTVN12_GLOBAL__N_18Derived2E:750
+ICTEXT: _ZTV8Derived1:250
+ICTEXT: 2
+ICTEXT: {{.*}}vtable_prof.cc;_ZTVN12_GLOBAL__N_18Derived2E:750
+ICTEXT: _ZTV8Derived1:250
diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profdata/llvm-profdata.cpp
index e8ee3c2..0b78564 100644
--- a/llvm/tools/llvm-profdata/llvm-profdata.cpp
+++ b/llvm/tools/llvm-profdata/llvm-profdata.cpp
@@ -361,6 +361,9 @@ cl::opt<bool> ShowIndirectCallTargets(
     "ic-targets", cl::init(false),
     cl::desc("Show indirect call site target values for shown functions"),
     cl::sub(ShowSubcommand));
+cl::opt<bool> ShowVTables("show-vtables", cl::init(false),
+                          cl::desc("Show vtable names for shown functions"),
+                          cl::sub(ShowSubcommand));
 cl::opt<bool> ShowMemOPSizes(
     "memop-sizes", cl::init(false),
     cl::desc("Show the profiled sizes of the memory intrinsic calls "
@@ -739,6 +742,13 @@ static void loadInput(const WeightedFile &Input, SymbolRemapper *Remapper,
     });
   }
 
+  const InstrProfSymtab &symtab = Reader->getSymtab();
+  const auto &VTableNames = symtab.getVTableNames();
+
+  for (const auto &kv : VTableNames) {
+    WC->Writer.addVTableName(kv.getKey());
+  }
+
   if (Reader->hasTemporalProfile()) {
     auto &Traces = Reader->getTemporalProfTraces(Input.Weight);
     if (!Traces.empty())
@@ -2834,6 +2844,10 @@ static int showInstrProfile(ShowFormat SFormat, raw_fd_ostream &OS) {
         OS << "    Indirect Call Site Count: "
            << Func.getNumValueSites(IPVK_IndirectCallTarget) << "\n";
 
+      if (ShowVTables)
+        OS << "    Number of instrumented vtables: "
+           << Func.getNumValueSites(IPVK_VTableTarget) << "\n";
+
       uint32_t NumMemOPCalls = Func.getNumValueSites(IPVK_MemOPSize);
       if (ShowMemOPSizes && NumMemOPCalls > 0)
         OS << "    Number of Memory Intrinsics Calls: " << NumMemOPCalls
@@ -2855,6 +2869,13 @@ static int showInstrProfile(ShowFormat SFormat, raw_fd_ostream &OS) {
                               &(Reader->getSymtab()));
       }
 
+      if (ShowVTables) {
+        OS << "    VTable Results:\n";
+        traverseAllValueSites(Func, IPVK_VTableTarget,
+                              VPStats[IPVK_VTableTarget], OS,
+                              &(Reader->getSymtab()));
+      }
+
       if (ShowMemOPSizes && NumMemOPCalls > 0) {
         OS << "    Memory Intrinsic Size Results:\n";
         traverseAllValueSites(Func, IPVK_MemOPSize, VPStats[IPVK_MemOPSize], OS,
@@ -2903,6 +2924,11 @@ static int showInstrProfile(ShowFormat SFormat, raw_fd_ostream &OS) {
                         VPStats[IPVK_IndirectCallTarget]);
   }
 
+  if (ShownFunctions && ShowVTables) {
+    OS << "Statistics for vtable profile:\n";
+    showValueSitesStats(OS, IPVK_VTableTarget, VPStats[IPVK_VTableTarget]);
+  }
+
   if (ShownFunctions && ShowMemOPSizes) {
     OS << "Statistics for memory intrinsic calls sizes profile:\n";
     showValueSitesStats(OS, IPVK_MemOPSize, VPStats[IPVK_MemOPSize]);
diff --git a/llvm/unittests/ProfileData/InstrProfTest.cpp b/llvm/unittests/ProfileData/InstrProfTest.cpp
index c932342..732f8fd 100644
--- a/llvm/unittests/ProfileData/InstrProfTest.cpp
+++ b/llvm/unittests/ProfileData/InstrProfTest.cpp
@@ -638,32 +638,78 @@ TEST_F(InstrProfTest, test_irpgo_read_deprecated_names) {
       Succeeded());
 }
 
+// callee1 to callee6 are from vtable1 to vtable6 respectively.
 static const char callee1[] = "callee1";
 static const char callee2[] = "callee2";
 static const char callee3[] = "callee3";
 static const char callee4[] = "callee4";
 static const char callee5[] = "callee5";
 static const char callee6[] = "callee6";
+// callee7 and callee8 are not from any vtables.
+static const char callee7[] = "callee7";
+static const char callee8[] = "callee8";
+// 'callee' is primarily used to create multiple-element vtables.
+static const char callee[] = "callee";
+static const uint64_t vtable1[] = {uint64_t(callee), uint64_t(callee1)};
+static const uint64_t vtable2[] = {uint64_t(callee2), uint64_t(callee)};
+static const uint64_t vtable3[] = {
+    uint64_t(callee),
+    uint64_t(callee3),
+};
+static const uint64_t vtable4[] = {uint64_t(callee4), uint64_t(callee)};
+static const uint64_t vtable5[] = {uint64_t(callee5), uint64_t(callee)};
+static const uint64_t vtable6[] = {uint64_t(callee6), uint64_t(callee)};
+
+// Returns the address of callee with a numbered suffix in vtable.
+static uint64_t getCalleeAddress(const uint64_t *vtableAddr) {
+  uint64_t CalleeAddr;
+  // Callee with a numbered suffix is the 2nd element in vtable1 and vtable3,
+  // and the 1st element in the rest of vtables.
+  if (vtableAddr == vtable1 || vtableAddr == vtable3)
+    CalleeAddr = uint64_t(vtableAddr) + 8;
+  else
+    CalleeAddr = uint64_t(vtableAddr);
+  return CalleeAddr;
+}
 
-TEST_P(InstrProfReaderWriterTest, icall_data_read_write) {
+TEST_P(InstrProfReaderWriterTest, icall_and_vtable_data_read_write) {
   NamedInstrProfRecord Record1("caller", 0x1234, {1, 2});
 
-  // 4 value sites.
-  Record1.reserveSites(IPVK_IndirectCallTarget, 4);
-  InstrProfValueData VD0[] = {
-      {(uint64_t)callee1, 1}, {(uint64_t)callee2, 2}, {(uint64_t)callee3, 3}};
-  Record1.addValueData(IPVK_IndirectCallTarget, 0, VD0, 3, nullptr);
-  // No value profile data at the second site.
-  Record1.addValueData(IPVK_IndirectCallTarget, 1, nullptr, 0, nullptr);
-  InstrProfValueData VD2[] = {{(uint64_t)callee1, 1}, {(uint64_t)callee2, 2}};
-  Record1.addValueData(IPVK_IndirectCallTarget, 2, VD2, 2, nullptr);
-  InstrProfValueData VD3[] = {{(uint64_t)callee1, 1}};
-  Record1.addValueData(IPVK_IndirectCallTarget, 3, VD3, 1, nullptr);
+  // 4 indirect call value sites.
+  {
+    Record1.reserveSites(IPVK_IndirectCallTarget, 4);
+    InstrProfValueData VD0[] = {
+        {(uint64_t)callee1, 1}, {(uint64_t)callee2, 2}, {(uint64_t)callee3, 3}};
+    Record1.addValueData(IPVK_IndirectCallTarget, 0, VD0, 3, nullptr);
+    // No value profile data at the second site.
+    Record1.addValueData(IPVK_IndirectCallTarget, 1, nullptr, 0, nullptr);
+    InstrProfValueData VD2[] = {{(uint64_t)callee1, 1}, {(uint64_t)callee2, 2}};
+    Record1.addValueData(IPVK_IndirectCallTarget, 2, VD2, 2, nullptr);
+    InstrProfValueData VD3[] = {{(uint64_t)callee7, 1}, {(uint64_t)callee8, 2}};
+    Record1.addValueData(IPVK_IndirectCallTarget, 3, VD3, 2, nullptr);
+  }
+
+  // 2 vtable value sites.
+  {
+    InstrProfValueData VD0[] = {
+        {getCalleeAddress(vtable1), 1},
+        {getCalleeAddress(vtable2), 2},
+        {getCalleeAddress(vtable3), 3},
+    };
+    InstrProfValueData VD2[] = {
+        {getCalleeAddress(vtable1), 1},
+        {getCalleeAddress(vtable2), 2},
+    };
+    Record1.addValueData(IPVK_VTableTarget, 0, VD0, 3, nullptr);
+    Record1.addValueData(IPVK_VTableTarget, 2, VD2, 2, nullptr);
+  }
 
   Writer.addRecord(std::move(Record1), getProfWeight(), Err);
   Writer.addRecord({"callee1", 0x1235, {3, 4}}, Err);
   Writer.addRecord({"callee2", 0x1235, {3, 4}}, Err);
   Writer.addRecord({"callee3", 0x1235, {3, 4}}, Err);
+  Writer.addRecord({"callee7", 0x1235, {3, 4}}, Err);
+  Writer.addRecord({"callee8", 0x1235, {3, 4}}, Err);
 
   // Set writer value prof data endianness.
   Writer.setValueProfDataEndianness(getEndianness());
@@ -676,24 +722,63 @@ TEST_P(InstrProfReaderWriterTest, icall_data_read_write) {
 
   Expected<InstrProfRecord> R = Reader->getInstrProfRecord("caller", 0x1234);
   ASSERT_THAT_ERROR(R.takeError(), Succeeded());
+
+  // Test the number of instrumented indirect call sites and the number of
+  // profiled values at each site.
   ASSERT_EQ(4U, R->getNumValueSites(IPVK_IndirectCallTarget));
   EXPECT_EQ(3U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 0));
   EXPECT_EQ(0U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 1));
   EXPECT_EQ(2U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 2));
-  EXPECT_EQ(1U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 3));
+  EXPECT_EQ(2U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 3));
+
+  // Test the number of instrumented vtable sites and the number of profiled
+  // values at each site.
+  ASSERT_EQ(R->getNumValueSites(IPVK_VTableTarget), 2U);
+  EXPECT_EQ(R->getNumValueDataForSite(IPVK_VTableTarget, 0), 3U);
+  EXPECT_EQ(R->getNumValueDataForSite(IPVK_VTableTarget, 1), 2U);
+
+  // First indirect site.
+  {
+    uint64_t TotalC;
+    auto VD = R->getValueForSite(IPVK_IndirectCallTarget, 0, &TotalC);
+
+    EXPECT_EQ(VD[0].Count, 3U * getProfWeight());
+    EXPECT_EQ(VD[1].Count, 2U * getProfWeight());
+    EXPECT_EQ(VD[2].Count, 1U * getProfWeight());
+    EXPECT_EQ(TotalC, 6U * getProfWeight());
+
+    EXPECT_STREQ((const char *)VD[0].Value, "callee3");
+    EXPECT_STREQ((const char *)VD[1].Value, "callee2");
+    EXPECT_STREQ((const char *)VD[2].Value, "callee1");
+  }
 
-  uint64_t TotalC;
-  std::unique_ptr<InstrProfValueData[]> VD =
-      R->getValueForSite(IPVK_IndirectCallTarget, 0, &TotalC);
+  // First vtable site.
+  {
+    uint64_t TotalC;
+    auto VD = R->getValueForSite(IPVK_VTableTarget, 0, &TotalC);
+
+    EXPECT_EQ(VD[0].Count, 3U * getProfWeight());
+    EXPECT_EQ(VD[1].Count, 2U * getProfWeight());
+    EXPECT_EQ(VD[2].Count, 1U * getProfWeight());
+    EXPECT_EQ(TotalC, 6U * getProfWeight());
+
+    EXPECT_EQ(VD[0].Value, getCalleeAddress(vtable3));
+    EXPECT_EQ(VD[1].Value, getCalleeAddress(vtable2));
+    EXPECT_EQ(VD[2].Value, getCalleeAddress(vtable1));
+  }
+
+  // Second vtable site.
+  {
+    uint64_t TotalC;
+    auto VD = R->getValueForSite(IPVK_VTableTarget, 1, &TotalC);
 
-  EXPECT_EQ(3U * getProfWeight(), VD[0].Count);
-  EXPECT_EQ(2U * getProfWeight(), VD[1].Count);
-  EXPECT_EQ(1U * getProfWeight(), VD[2].Count);
-  EXPECT_EQ(6U * getProfWeight(), TotalC);
+    EXPECT_EQ(VD[0].Count, 2U * getProfWeight());
+    EXPECT_EQ(VD[1].Count, 1U * getProfWeight());
+    EXPECT_EQ(TotalC, 3U * getProfWeight());
 
-  EXPECT_EQ(StringRef((const char *)VD[0].Value, 7), StringRef("callee3"));
-  EXPECT_EQ(StringRef((const char *)VD[1].Value, 7), StringRef("callee2"));
-  EXPECT_EQ(StringRef((const char *)VD[2].Value, 7), StringRef("callee1"));
+    EXPECT_EQ(VD[0].Value, getCalleeAddress(vtable2));
+    EXPECT_EQ(VD[1].Value, getCalleeAddress(vtable1));
+  }
 }
 
 INSTANTIATE_TEST_SUITE_P(
@@ -801,33 +886,53 @@ TEST_P(MaybeSparseInstrProfTest, annotate_vp_data) {
   ASSERT_EQ(1U, ValueData[3].Count);
 }
 
-TEST_P(MaybeSparseInstrProfTest, icall_data_merge) {
+TEST_P(MaybeSparseInstrProfTest, icall_and_vtable_data_merge) {
   static const char caller[] = "caller";
   NamedInstrProfRecord Record11(caller, 0x1234, {1, 2});
   NamedInstrProfRecord Record12(caller, 0x1234, {1, 2});
 
-  // 5 value sites.
-  Record11.reserveSites(IPVK_IndirectCallTarget, 5);
-  InstrProfValueData VD0[] = {{uint64_t(callee1), 1},
-                              {uint64_t(callee2), 2},
-                              {uint64_t(callee3), 3},
-                              {uint64_t(callee4), 4}};
-  Record11.addValueData(IPVK_IndirectCallTarget, 0, VD0, 4, nullptr);
+  // 5 value sites for indirect calls.
+  {
+    Record11.reserveSites(IPVK_IndirectCallTarget, 5);
+    InstrProfValueData VD0[] = {{uint64_t(callee1), 1},
+                                {uint64_t(callee2), 2},
+                                {uint64_t(callee3), 3},
+                                {uint64_t(callee4), 4}};
+    Record11.addValueData(IPVK_IndirectCallTarget, 0, VD0, 4, nullptr);
 
-  // No value profile data at the second site.
-  Record11.addValueData(IPVK_IndirectCallTarget, 1, nullptr, 0, nullptr);
+    // No value profile data at the second site.
+    Record11.addValueData(IPVK_IndirectCallTarget, 1, nullptr, 0, nullptr);
 
-  InstrProfValueData VD2[] = {
-      {uint64_t(callee1), 1}, {uint64_t(callee2), 2}, {uint64_t(callee3), 3}};
-  Record11.addValueData(IPVK_IndirectCallTarget, 2, VD2, 3, nullptr);
+    InstrProfValueData VD2[] = {
+        {uint64_t(callee1), 1}, {uint64_t(callee2), 2}, {uint64_t(callee3), 3}};
+    Record11.addValueData(IPVK_IndirectCallTarget, 2, VD2, 3, nullptr);
 
-  InstrProfValueData VD3[] = {{uint64_t(callee1), 1}};
-  Record11.addValueData(IPVK_IndirectCallTarget, 3, VD3, 1, nullptr);
+    InstrProfValueData VD3[] = {{uint64_t(callee7), 1}, {uint64_t(callee8), 2}};
+    Record11.addValueData(IPVK_IndirectCallTarget, 3, VD3, 2, nullptr);
 
-  InstrProfValueData VD4[] = {{uint64_t(callee1), 1},
-                              {uint64_t(callee2), 2},
-                              {uint64_t(callee3), 3}};
-  Record11.addValueData(IPVK_IndirectCallTarget, 4, VD4, 3, nullptr);
+    InstrProfValueData VD4[] = {
+        {uint64_t(callee1), 1}, {uint64_t(callee2), 2}, {uint64_t(callee3), 3}};
+    Record11.addValueData(IPVK_IndirectCallTarget, 4, VD4, 3, nullptr);
+  }
+  // 3 value sites for vtables.
+  {
+    Record11.reserveSites(IPVK_VTableTarget, 3);
+    InstrProfValueData VD0[] = {{getCalleeAddress(vtable1), 1},
+                                {getCalleeAddress(vtable2), 2},
+                                {getCalleeAddress(vtable3), 3},
+                                {getCalleeAddress(vtable4), 4}};
+    Record11.addValueData(IPVK_VTableTarget, 0, VD0, 4, nullptr);
+
+    InstrProfValueData VD2[] = {{getCalleeAddress(vtable1), 1},
+                                {getCalleeAddress(vtable2), 2},
+                                {getCalleeAddress(vtable3), 3}};
+    Record11.addValueData(IPVK_VTableTarget, 1, VD2, 3, nullptr);
+
+    InstrProfValueData VD4[] = {{getCalleeAddress(vtable1), 1},
+                                {getCalleeAddress(vtable2), 2},
+                                {getCalleeAddress(vtable3), 3}};
+    Record11.addValueData(IPVK_VTableTarget, 3, VD4, 3, nullptr);
+  }
 
   // A different record for the same caller.
   Record12.reserveSites(IPVK_IndirectCallTarget, 5);
@@ -843,11 +948,28 @@ TEST_P(MaybeSparseInstrProfTest, icall_data_merge) {
 
   Record12.addValueData(IPVK_IndirectCallTarget, 3, nullptr, 0, nullptr);
 
-  InstrProfValueData VD42[] = {{uint64_t(callee1), 1},
-                               {uint64_t(callee2), 2},
-                               {uint64_t(callee3), 3}};
+  InstrProfValueData VD42[] = {
+      {uint64_t(callee1), 1}, {uint64_t(callee2), 2}, {uint64_t(callee3), 3}};
   Record12.addValueData(IPVK_IndirectCallTarget, 4, VD42, 3, nullptr);
 
+  // 3 value sites for vtables.
+  {
+    Record12.reserveSites(IPVK_VTableTarget, 3);
+    InstrProfValueData VD0[] = {{getCalleeAddress(vtable2), 5},
+                                {getCalleeAddress(vtable3), 3}};
+    Record12.addValueData(IPVK_VTableTarget, 0, VD0, 2, nullptr);
+
+    InstrProfValueData VD2[] = {{getCalleeAddress(vtable2), 1},
+                                {getCalleeAddress(vtable3), 3},
+                                {getCalleeAddress(vtable4), 4}};
+    Record12.addValueData(IPVK_VTableTarget, 1, VD2, 3, nullptr);
+
+    InstrProfValueData VD4[] = {{getCalleeAddress(vtable1), 1},
+                                {getCalleeAddress(vtable2), 2},
+                                {getCalleeAddress(vtable3), 3}};
+    Record12.addValueData(IPVK_VTableTarget, 3, VD4, 3, nullptr);
+  }
+
   Writer.addRecord(std::move(Record11), Err);
   // Merge profile data.
   Writer.addRecord(std::move(Record12), Err);
@@ -857,53 +979,95 @@ TEST_P(MaybeSparseInstrProfTest, icall_data_merge) {
   Writer.addRecord({callee3, 0x1235, {3, 4}}, Err);
   Writer.addRecord({callee3, 0x1235, {3, 4}}, Err);
   Writer.addRecord({callee4, 0x1235, {3, 5}}, Err);
+  Writer.addRecord({callee7, 0x1235, {3, 5}}, Err);
+  Writer.addRecord({callee8, 0x1235, {3, 5}}, Err);
   auto Profile = Writer.writeBuffer();
   readProfile(std::move(Profile));
 
+  // Test the number of instrumented value sites and the number of profiled
+  // values for each site.
   Expected<InstrProfRecord> R = Reader->getInstrProfRecord("caller", 0x1234);
   EXPECT_THAT_ERROR(R.takeError(), Succeeded());
+  // For indirect calls.
   ASSERT_EQ(5U, R->getNumValueSites(IPVK_IndirectCallTarget));
   ASSERT_EQ(4U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 0));
   ASSERT_EQ(0U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 1));
   ASSERT_EQ(4U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 2));
-  ASSERT_EQ(1U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 3));
+  ASSERT_EQ(2U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 3));
   ASSERT_EQ(3U, R->getNumValueDataForSite(IPVK_IndirectCallTarget, 4));
+  // For vtables.
+  ASSERT_EQ(R->getNumValueSites(IPVK_VTableTarget), 3U);
+  ASSERT_EQ(R->getNumValueDataForSite(IPVK_VTableTarget, 0), 4U);
+  ASSERT_EQ(R->getNumValueDataForSite(IPVK_VTableTarget, 1), 4U);
+  ASSERT_EQ(R->getNumValueDataForSite(IPVK_VTableTarget, 2), 3U);
+
+  // Test the merged values for indirect calls.
+  {
+    auto VD = R->getValueForSite(IPVK_IndirectCallTarget, 0);
+    EXPECT_STREQ((const char *)VD[0].Value, "callee2");
+    EXPECT_EQ(VD[0].Count, 7U);
+    EXPECT_STREQ((const char *)VD[1].Value, "callee3");
+    EXPECT_EQ(VD[1].Count, 6U);
+    EXPECT_STREQ((const char *)VD[2].Value, "callee4");
+    EXPECT_EQ(VD[2].Count, 4U);
+    EXPECT_STREQ((const char *)VD[3].Value, "callee1");
+    EXPECT_EQ(VD[3].Count, 1U);
+
+    auto VD_2(R->getValueForSite(IPVK_IndirectCallTarget, 2));
+    EXPECT_STREQ((const char *)VD_2[0].Value, "callee3");
+    EXPECT_EQ(VD_2[0].Count, 6U);
+    EXPECT_STREQ((const char *)VD_2[1].Value, "callee4");
+    EXPECT_EQ(VD_2[1].Count, 4U);
+    EXPECT_STREQ((const char *)VD_2[2].Value, "callee2");
+    EXPECT_EQ(VD_2[2].Count, 3U);
+    EXPECT_STREQ((const char *)VD_2[3].Value, "callee1");
+    EXPECT_EQ(VD_2[3].Count, 1U);
+
+    auto VD_3(R->getValueForSite(IPVK_IndirectCallTarget, 3));
+    EXPECT_STREQ((const char *)VD_3[0].Value, "callee8");
+    EXPECT_EQ(VD_3[0].Count, 2U);
+    EXPECT_STREQ((const char *)VD_3[1].Value, "callee7");
+    EXPECT_EQ(VD_3[1].Count, 1U);
+
+    auto VD_4(R->getValueForSite(IPVK_IndirectCallTarget, 4));
+    EXPECT_STREQ((const char *)VD_4[0].Value, "callee3");
+    EXPECT_EQ(VD_4[0].Count, 6U);
+    EXPECT_STREQ((const char *)VD_4[1].Value, "callee2");
+    EXPECT_EQ(VD_4[1].Count, 4U);
+    EXPECT_STREQ((const char *)VD_4[2].Value, "callee1");
+    EXPECT_EQ(VD_4[2].Count, 2U);
+  }
 
-  std::unique_ptr<InstrProfValueData[]> VD =
-      R->getValueForSite(IPVK_IndirectCallTarget, 0);
-  ASSERT_EQ(StringRef((const char *)VD[0].Value, 7), StringRef("callee2"));
-  ASSERT_EQ(7U, VD[0].Count);
-  ASSERT_EQ(StringRef((const char *)VD[1].Value, 7), StringRef("callee3"));
-  ASSERT_EQ(6U, VD[1].Count);
-  ASSERT_EQ(StringRef((const char *)VD[2].Value, 7), StringRef("callee4"));
-  ASSERT_EQ(4U, VD[2].Count);
-  ASSERT_EQ(StringRef((const char *)VD[3].Value, 7), StringRef("callee1"));
-  ASSERT_EQ(1U, VD[3].Count);
-
-  std::unique_ptr<InstrProfValueData[]> VD_2(
-      R->getValueForSite(IPVK_IndirectCallTarget, 2));
-  ASSERT_EQ(StringRef((const char *)VD_2[0].Value, 7), StringRef("callee3"));
-  ASSERT_EQ(6U, VD_2[0].Count);
-  ASSERT_EQ(StringRef((const char *)VD_2[1].Value, 7), StringRef("callee4"));
-  ASSERT_EQ(4U, VD_2[1].Count);
-  ASSERT_EQ(StringRef((const char *)VD_2[2].Value, 7), StringRef("callee2"));
-  ASSERT_EQ(3U, VD_2[2].Count);
-  ASSERT_EQ(StringRef((const char *)VD_2[3].Value, 7), StringRef("callee1"));
-  ASSERT_EQ(1U, VD_2[3].Count);
-
-  std::unique_ptr<InstrProfValueData[]> VD_3(
-      R->getValueForSite(IPVK_IndirectCallTarget, 3));
-  ASSERT_EQ(StringRef((const char *)VD_3[0].Value, 7), StringRef("callee1"));
-  ASSERT_EQ(1U, VD_3[0].Count);
-
-  std::unique_ptr<InstrProfValueData[]> VD_4(
-      R->getValueForSite(IPVK_IndirectCallTarget, 4));
-  ASSERT_EQ(StringRef((const char *)VD_4[0].Value, 7), StringRef("callee3"));
-  ASSERT_EQ(6U, VD_4[0].Count);
-  ASSERT_EQ(StringRef((const char *)VD_4[1].Value, 7), StringRef("callee2"));
-  ASSERT_EQ(4U, VD_4[1].Count);
-  ASSERT_EQ(StringRef((const char *)VD_4[2].Value, 7), StringRef("callee1"));
-  ASSERT_EQ(2U, VD_4[2].Count);
+  // Test the merged values for vtables
+  {
+    auto VD0 = R->getValueForSite(IPVK_VTableTarget, 0);
+    EXPECT_EQ(VD0[0].Value, getCalleeAddress(vtable2));
+    EXPECT_EQ(VD0[0].Count, 7U);
+    EXPECT_EQ(VD0[1].Value, getCalleeAddress(vtable3));
+    EXPECT_EQ(VD0[1].Count, 6U);
+    EXPECT_EQ(VD0[2].Value, getCalleeAddress(vtable4));
+    EXPECT_EQ(VD0[2].Count, 4U);
+    EXPECT_EQ(VD0[3].Value, getCalleeAddress(vtable1));
+    EXPECT_EQ(VD0[3].Count, 1U);
+
+    auto VD1 = R->getValueForSite(IPVK_VTableTarget, 1);
+    EXPECT_EQ(VD1[0].Value, getCalleeAddress(vtable3));
+    EXPECT_EQ(VD1[0].Count, 6U);
+    EXPECT_EQ(VD1[1].Value, getCalleeAddress(vtable4));
+    EXPECT_EQ(VD1[1].Count, 4U);
+    EXPECT_EQ(VD1[2].Value, getCalleeAddress(vtable2));
+    EXPECT_EQ(VD1[2].Count, 3U);
+    EXPECT_EQ(VD1[3].Value, getCalleeAddress(vtable1));
+    EXPECT_EQ(VD1[3].Count, 1U);
+
+    auto VD2 = R->getValueForSite(IPVK_VTableTarget, 2);
+    EXPECT_EQ(VD2[0].Value, getCalleeAddress(vtable3));
+    EXPECT_EQ(VD2[0].Count, 6U);
+    EXPECT_EQ(VD2[1].Value, getCalleeAddress(vtable2));
+    EXPECT_EQ(VD2[1].Count, 4U);
+    EXPECT_EQ(VD2[2].Value, getCalleeAddress(vtable1));
+    EXPECT_EQ(VD2[2].Count, 2U);
+  }
 }
 
 struct ValueProfileMergeEdgeCaseTest
@@ -1027,30 +1191,62 @@ INSTANTIATE_TEST_SUITE_P(
     EdgeCaseTest, ValueProfileMergeEdgeCaseTest,
     ::testing::Combine(::testing::Bool(), /* Sparse */
                        ::testing::Values(IPVK_IndirectCallTarget,
-                                         IPVK_MemOPSize) /* ValueKind */
+                                         IPVK_MemOPSize,
+                                         IPVK_VTableTarget) /* ValueKind */
                        ));
 
 static void addValueProfData(InstrProfRecord &Record) {
-  Record.reserveSites(IPVK_IndirectCallTarget, 5);
-  InstrProfValueData VD0[] = {{uint64_t(callee1), 400},
-                              {uint64_t(callee2), 1000},
-                              {uint64_t(callee3), 500},
-                              {uint64_t(callee4), 300},
-                              {uint64_t(callee5), 100}};
-  Record.addValueData(IPVK_IndirectCallTarget, 0, VD0, 5, nullptr);
-  InstrProfValueData VD1[] = {{uint64_t(callee5), 800},
-                              {uint64_t(callee3), 1000},
-                              {uint64_t(callee2), 2500},
-                              {uint64_t(callee1), 1300}};
-  Record.addValueData(IPVK_IndirectCallTarget, 1, VD1, 4, nullptr);
-  InstrProfValueData VD2[] = {{uint64_t(callee6), 800},
-                              {uint64_t(callee3), 1000},
-                              {uint64_t(callee4), 5500}};
-  Record.addValueData(IPVK_IndirectCallTarget, 2, VD2, 3, nullptr);
-  InstrProfValueData VD3[] = {{uint64_t(callee2), 1800},
-                              {uint64_t(callee3), 2000}};
-  Record.addValueData(IPVK_IndirectCallTarget, 3, VD3, 2, nullptr);
-  Record.addValueData(IPVK_IndirectCallTarget, 4, nullptr, 0, nullptr);
+  // Add test data for indirect calls.
+  {
+    Record.reserveSites(IPVK_IndirectCallTarget, 6);
+    InstrProfValueData VD0[] = {{uint64_t(callee1), 400},
+                                {uint64_t(callee2), 1000},
+                                {uint64_t(callee3), 500},
+                                {uint64_t(callee4), 300},
+                                {uint64_t(callee5), 100}};
+    Record.addValueData(IPVK_IndirectCallTarget, 0, VD0, 5, nullptr);
+    InstrProfValueData VD1[] = {{uint64_t(callee5), 800},
+                                {uint64_t(callee3), 1000},
+                                {uint64_t(callee2), 2500},
+                                {uint64_t(callee1), 1300}};
+    Record.addValueData(IPVK_IndirectCallTarget, 1, VD1, 4, nullptr);
+    InstrProfValueData VD2[] = {{uint64_t(callee6), 800},
+                                {uint64_t(callee3), 1000},
+                                {uint64_t(callee4), 5500}};
+    Record.addValueData(IPVK_IndirectCallTarget, 2, VD2, 3, nullptr);
+    InstrProfValueData VD3[] = {{uint64_t(callee2), 1800},
+                                {uint64_t(callee3), 2000}};
+    Record.addValueData(IPVK_IndirectCallTarget, 3, VD3, 2, nullptr);
+    Record.addValueData(IPVK_IndirectCallTarget, 4, nullptr, 0, nullptr);
+    InstrProfValueData VD5[] = {{uint64_t(callee7), 1234},
+                                {uint64_t(callee8), 5678}};
+    Record.addValueData(IPVK_IndirectCallTarget, 5, VD5, 2, nullptr);
+  }
+
+  // Add test data for vtables
+  {
+    Record.reserveSites(IPVK_VTableTarget, 4);
+    InstrProfValueData VD0[] = {
+        {getCalleeAddress(vtable1), 400}, {getCalleeAddress(vtable2), 1000},
+        {getCalleeAddress(vtable3), 500}, {getCalleeAddress(vtable4), 300},
+        {getCalleeAddress(vtable5), 100},
+    };
+    InstrProfValueData VD1[] = {{getCalleeAddress(vtable5), 800},
+                                {getCalleeAddress(vtable3), 1000},
+                                {getCalleeAddress(vtable2), 2500},
+                                {getCalleeAddress(vtable1), 1300}};
+    InstrProfValueData VD2[] = {
+        {getCalleeAddress(vtable6), 800},
+        {getCalleeAddress(vtable3), 1000},
+        {getCalleeAddress(vtable4), 5500},
+    };
+    InstrProfValueData VD3[] = {{getCalleeAddress(vtable2), 1800},
+                                {getCalleeAddress(vtable3), 2000}};
+    Record.addValueData(IPVK_VTableTarget, 0, VD0, 5, nullptr);
+    Record.addValueData(IPVK_VTableTarget, 1, VD1, 4, nullptr);
+    Record.addValueData(IPVK_VTableTarget, 2, VD2, 3, nullptr);
+    Record.addValueData(IPVK_VTableTarget, 3, VD3, 2, nullptr);
+  }
 }
 
 TEST(ValueProfileReadWriteTest, value_prof_data_read_write) {
@@ -1063,59 +1259,107 @@ TEST(ValueProfileReadWriteTest, value_prof_data_read_write) {
   VPData->deserializeTo(Record, nullptr);
 
   // Now read data from Record and sanity check the data
-  ASSERT_EQ(5U, Record.getNumValueSites(IPVK_IndirectCallTarget));
+  ASSERT_EQ(6U, Record.getNumValueSites(IPVK_IndirectCallTarget));
   ASSERT_EQ(5U, Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 0));
   ASSERT_EQ(4U, Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 1));
   ASSERT_EQ(3U, Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 2));
   ASSERT_EQ(2U, Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 3));
   ASSERT_EQ(0U, Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 4));
+  ASSERT_EQ(2U, Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 5));
 
   auto Cmp = [](const InstrProfValueData &VD1, const InstrProfValueData &VD2) {
     return VD1.Count > VD2.Count;
   };
+
   std::unique_ptr<InstrProfValueData[]> VD_0(
       Record.getValueForSite(IPVK_IndirectCallTarget, 0));
   llvm::sort(&VD_0[0], &VD_0[5], Cmp);
-  ASSERT_EQ(StringRef((const char *)VD_0[0].Value, 7), StringRef("callee2"));
-  ASSERT_EQ(1000U, VD_0[0].Count);
-  ASSERT_EQ(StringRef((const char *)VD_0[1].Value, 7), StringRef("callee3"));
-  ASSERT_EQ(500U, VD_0[1].Count);
-  ASSERT_EQ(StringRef((const char *)VD_0[2].Value, 7), StringRef("callee1"));
-  ASSERT_EQ(400U, VD_0[2].Count);
-  ASSERT_EQ(StringRef((const char *)VD_0[3].Value, 7), StringRef("callee4"));
-  ASSERT_EQ(300U, VD_0[3].Count);
-  ASSERT_EQ(StringRef((const char *)VD_0[4].Value, 7), StringRef("callee5"));
-  ASSERT_EQ(100U, VD_0[4].Count);
+  EXPECT_STREQ((const char *)VD_0[0].Value, "callee2");
+  EXPECT_EQ(1000U, VD_0[0].Count);
+  EXPECT_STREQ((const char *)VD_0[1].Value, "callee3");
+  EXPECT_EQ(500U, VD_0[1].Count);
+  EXPECT_STREQ((const char *)VD_0[2].Value, "callee1");
+  EXPECT_EQ(400U, VD_0[2].Count);
+  EXPECT_STREQ((const char *)VD_0[3].Value, "callee4");
+  EXPECT_EQ(300U, VD_0[3].Count);
+  EXPECT_STREQ((const char *)VD_0[4].Value, "callee5");
+  EXPECT_EQ(100U, VD_0[4].Count);
 
   std::unique_ptr<InstrProfValueData[]> VD_1(
       Record.getValueForSite(IPVK_IndirectCallTarget, 1));
   llvm::sort(&VD_1[0], &VD_1[4], Cmp);
-  ASSERT_EQ(StringRef((const char *)VD_1[0].Value, 7), StringRef("callee2"));
-  ASSERT_EQ(2500U, VD_1[0].Count);
-  ASSERT_EQ(StringRef((const char *)VD_1[1].Value, 7), StringRef("callee1"));
-  ASSERT_EQ(1300U, VD_1[1].Count);
-  ASSERT_EQ(StringRef((const char *)VD_1[2].Value, 7), StringRef("callee3"));
-  ASSERT_EQ(1000U, VD_1[2].Count);
-  ASSERT_EQ(StringRef((const char *)VD_1[3].Value, 7), StringRef("callee5"));
-  ASSERT_EQ(800U, VD_1[3].Count);
+  EXPECT_STREQ((const char *)VD_1[0].Value, "callee2");
+  EXPECT_EQ(VD_1[0].Count, 2500U);
+  EXPECT_STREQ((const char *)VD_1[1].Value, "callee1");
+  EXPECT_EQ(VD_1[1].Count, 1300U);
+  EXPECT_STREQ((const char *)VD_1[2].Value, "callee3");
+  EXPECT_EQ(VD_1[2].Count, 1000U);
+  EXPECT_STREQ((const char *)VD_1[3].Value, "callee5");
+  EXPECT_EQ(VD_1[3].Count, 800U);
 
   std::unique_ptr<InstrProfValueData[]> VD_2(
       Record.getValueForSite(IPVK_IndirectCallTarget, 2));
   llvm::sort(&VD_2[0], &VD_2[3], Cmp);
-  ASSERT_EQ(StringRef((const char *)VD_2[0].Value, 7), StringRef("callee4"));
-  ASSERT_EQ(5500U, VD_2[0].Count);
-  ASSERT_EQ(StringRef((const char *)VD_2[1].Value, 7), StringRef("callee3"));
-  ASSERT_EQ(1000U, VD_2[1].Count);
-  ASSERT_EQ(StringRef((const char *)VD_2[2].Value, 7), StringRef("callee6"));
-  ASSERT_EQ(800U, VD_2[2].Count);
+  EXPECT_STREQ((const char *)VD_2[0].Value, "callee4");
+  EXPECT_EQ(VD_2[0].Count, 5500U);
+  EXPECT_STREQ((const char *)VD_2[1].Value, "callee3");
+  EXPECT_EQ(VD_2[1].Count, 1000U);
+  EXPECT_STREQ((const char *)VD_2[2].Value, "callee6");
+  EXPECT_EQ(VD_2[2].Count, 800U);
 
   std::unique_ptr<InstrProfValueData[]> VD_3(
       Record.getValueForSite(IPVK_IndirectCallTarget, 3));
   llvm::sort(&VD_3[0], &VD_3[2], Cmp);
-  ASSERT_EQ(StringRef((const char *)VD_3[0].Value, 7), StringRef("callee3"));
-  ASSERT_EQ(2000U, VD_3[0].Count);
-  ASSERT_EQ(StringRef((const char *)VD_3[1].Value, 7), StringRef("callee2"));
-  ASSERT_EQ(1800U, VD_3[1].Count);
+  EXPECT_STREQ((const char *)VD_3[0].Value, "callee3");
+  EXPECT_EQ(VD_3[0].Count, 2000U);
+  EXPECT_STREQ((const char *)VD_3[1].Value, "callee2");
+  EXPECT_EQ(VD_3[1].Count, 1800U);
+
+  ASSERT_EQ(Record.getNumValueSites(IPVK_VTableTarget), 4U);
+  ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 0), 5U);
+  ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 1), 4U);
+  ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 2), 3U);
+  ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 3), 2U);
+
+  auto VD0(Record.getValueForSite(IPVK_VTableTarget, 0));
+  llvm::sort(&VD0[0], &VD0[5], Cmp);
+  EXPECT_EQ(VD0[0].Value, getCalleeAddress(vtable2));
+  EXPECT_EQ(VD0[0].Count, 1000U);
+  EXPECT_EQ(VD0[1].Value, getCalleeAddress(vtable3));
+  EXPECT_EQ(VD0[1].Count, 500U);
+  EXPECT_EQ(VD0[2].Value, getCalleeAddress(vtable1));
+  EXPECT_EQ(VD0[2].Count, 400U);
+  EXPECT_EQ(VD0[3].Value, getCalleeAddress(vtable4));
+  EXPECT_EQ(VD0[3].Count, 300U);
+  EXPECT_EQ(VD0[4].Value, getCalleeAddress(vtable5));
+  EXPECT_EQ(VD0[4].Count, 100U);
+
+  auto VD1(Record.getValueForSite(IPVK_VTableTarget, 1));
+  llvm::sort(&VD1[0], &VD1[4], Cmp);
+  EXPECT_EQ(VD1[0].Value, getCalleeAddress(vtable2));
+  EXPECT_EQ(VD1[0].Count, 2500U);
+  EXPECT_EQ(VD1[1].Value, getCalleeAddress(vtable1));
+  EXPECT_EQ(VD1[1].Count, 1300U);
+  EXPECT_EQ(VD1[2].Value, getCalleeAddress(vtable3));
+  EXPECT_EQ(VD1[2].Count, 1000U);
+  EXPECT_EQ(VD1[3].Value, getCalleeAddress(vtable5));
+  EXPECT_EQ(VD1[3].Count, 800U);
+
+  auto VD2(Record.getValueForSite(IPVK_VTableTarget, 2));
+  llvm::sort(&VD2[0], &VD2[3], Cmp);
+  EXPECT_EQ(VD2[0].Value, getCalleeAddress(vtable4));
+  EXPECT_EQ(VD2[0].Count, 5500U);
+  EXPECT_EQ(VD2[1].Value, getCalleeAddress(vtable3));
+  EXPECT_EQ(VD2[1].Count, 1000U);
+  EXPECT_EQ(VD2[2].Value, getCalleeAddress(vtable6));
+  EXPECT_EQ(VD2[2].Count, 800U);
+
+  auto VD3(Record.getValueForSite(IPVK_VTableTarget, 3));
+  llvm::sort(&VD3[0], &VD3[2], Cmp);
+  EXPECT_EQ(VD3[0].Value, getCalleeAddress(vtable3));
+  EXPECT_EQ(VD3[0].Count, 2000U);
+  EXPECT_EQ(VD3[1].Value, getCalleeAddress(vtable2));
+  EXPECT_EQ(VD3[1].Count, 1800U);
 }
 
 TEST(ValueProfileReadWriteTest, symtab_mapping) {
@@ -1132,27 +1376,121 @@ TEST(ValueProfileReadWriteTest, symtab_mapping) {
   Symtab.mapAddress(uint64_t(callee4), 0x4000ULL);
   // Missing mapping for callee5
 
+  auto getVTableStartAddr = [](const uint64_t *vtable) -> uint64_t {
+    return uint64_t(vtable);
+  };
+  auto getVTableEndAddr = [](const uint64_t *vtable) -> uint64_t {
+    return uint64_t(vtable) + 16;
+  };
+  auto getVTableMidAddr = [](const uint64_t *vtable) -> uint64_t {
+    return uint64_t(vtable) + 8;
+  };
+  // vtable1, vtable2, vtable3, vtable4 get mapped; vtable5, vtable6 are not
+  // mapped.
+  Symtab.mapVTableAddress(getVTableStartAddr(vtable1),
+                          getVTableEndAddr(vtable1), MD5Hash("vtable1"));
+  Symtab.mapVTableAddress(getVTableStartAddr(vtable2),
+                          getVTableEndAddr(vtable2), MD5Hash("vtable2"));
+  Symtab.mapVTableAddress(getVTableStartAddr(vtable3),
+                          getVTableEndAddr(vtable3), MD5Hash("vtable3"));
+  Symtab.mapVTableAddress(getVTableStartAddr(vtable4),
+                          getVTableEndAddr(vtable4), MD5Hash("vtable4"));
+
   VPData->deserializeTo(Record, &Symtab);
 
   // Now read data from Record and sanity check the data
-  ASSERT_EQ(5U, Record.getNumValueSites(IPVK_IndirectCallTarget));
-  ASSERT_EQ(5U, Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 0));
+  ASSERT_EQ(Record.getNumValueSites(IPVK_IndirectCallTarget), 6U);
+  ASSERT_EQ(Record.getNumValueDataForSite(IPVK_IndirectCallTarget, 0), 5U);
+
+  // Look up the value correpsonding to the middle of a vtable in symtab and
+  // test that it's the hash of the name.
+  EXPECT_EQ(Symtab.getVTableHashFromAddress(getVTableMidAddr(vtable1)),
+            MD5Hash("vtable1"));
+  EXPECT_EQ(Symtab.getVTableHashFromAddress(getVTableMidAddr(vtable2)),
+            MD5Hash("vtable2"));
+  EXPECT_EQ(Symtab.getVTableHashFromAddress(getVTableMidAddr(vtable3)),
+            MD5Hash("vtable3"));
+  EXPECT_EQ(Symtab.getVTableHashFromAddress(getVTableMidAddr(vtable4)),
+            MD5Hash("vtable4"));
 
   auto Cmp = [](const InstrProfValueData &VD1, const InstrProfValueData &VD2) {
     return VD1.Count > VD2.Count;
   };
-  std::unique_ptr<InstrProfValueData[]> VD_0(
-      Record.getValueForSite(IPVK_IndirectCallTarget, 0));
+  auto VD_0(Record.getValueForSite(IPVK_IndirectCallTarget, 0));
   llvm::sort(&VD_0[0], &VD_0[5], Cmp);
   ASSERT_EQ(VD_0[0].Value, 0x2000ULL);
-  ASSERT_EQ(1000U, VD_0[0].Count);
+  ASSERT_EQ(VD_0[0].Count, 1000U);
   ASSERT_EQ(VD_0[1].Value, 0x3000ULL);
-  ASSERT_EQ(500U, VD_0[1].Count);
+  ASSERT_EQ(VD_0[1].Count, 500U);
   ASSERT_EQ(VD_0[2].Value, 0x1000ULL);
-  ASSERT_EQ(400U, VD_0[2].Count);
+  ASSERT_EQ(VD_0[2].Count, 400U);
 
   // callee5 does not have a mapped value -- default to 0.
   ASSERT_EQ(VD_0[4].Value, 0ULL);
+
+  // Sanity check the vtable value data
+  ASSERT_EQ(Record.getNumValueSites(IPVK_VTableTarget), 4U);
+
+  {
+    // The first vtable site.
+    auto VD(Record.getValueForSite(IPVK_VTableTarget, 0));
+    ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 0), 5U);
+    llvm::sort(&VD[0], &VD[5], Cmp);
+    EXPECT_EQ(VD[0].Count, 1000U);
+    EXPECT_EQ(VD[0].Value, MD5Hash("vtable2"));
+    EXPECT_EQ(VD[1].Count, 500U);
+    EXPECT_EQ(VD[1].Value, MD5Hash("vtable3"));
+    EXPECT_EQ(VD[2].Value, MD5Hash("vtable1"));
+    EXPECT_EQ(VD[2].Count, 400U);
+    EXPECT_EQ(VD[3].Value, MD5Hash("vtable4"));
+    EXPECT_EQ(VD[3].Count, 300U);
+
+    // vtable5 isn't mapped -- default to 0.
+    EXPECT_EQ(VD[4].Value, 0U);
+    EXPECT_EQ(VD[4].Count, 100U);
+  }
+
+  {
+    // The second vtable site.
+    auto VD(Record.getValueForSite(IPVK_VTableTarget, 1));
+    ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 1), 4U);
+    llvm::sort(&VD[0], &VD[4], Cmp);
+    EXPECT_EQ(VD[0].Value, MD5Hash("vtable2"));
+    EXPECT_EQ(VD[0].Count, 2500U);
+    EXPECT_EQ(VD[1].Value, MD5Hash("vtable1"));
+    EXPECT_EQ(VD[1].Count, 1300U);
+
+    EXPECT_EQ(VD[2].Value, MD5Hash("vtable3"));
+    EXPECT_EQ(VD[2].Count, 1000U);
+    // vtable5 isn't mapped -- default to 0.
+    EXPECT_EQ(VD[3].Value, 0U);
+    EXPECT_EQ(VD[3].Count, 800U);
+  }
+
+  {
+    // The third vtable site.
+    auto VD(Record.getValueForSite(IPVK_VTableTarget, 2));
+    ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 2), 3U);
+    llvm::sort(&VD[0], &VD[3], Cmp);
+    EXPECT_EQ(VD[0].Count, 5500U);
+    EXPECT_EQ(VD[0].Value, MD5Hash("vtable4"));
+    EXPECT_EQ(VD[1].Count, 1000U);
+    EXPECT_EQ(VD[1].Value, MD5Hash("vtable3"));
+    // vtable6 isn't mapped -- default to 0.
+    EXPECT_EQ(VD[2].Value, 0U);
+    EXPECT_EQ(VD[2].Count, 800U);
+  }
+
+  {
+    // The fourth vtable site.
+    auto VD(Record.getValueForSite(IPVK_VTableTarget, 3));
+    ASSERT_EQ(Record.getNumValueDataForSite(IPVK_VTableTarget, 3), 2U);
+    llvm::sort(&VD[0], &VD[2], Cmp);
+    EXPECT_EQ(VD[0].Count, 2000U);
+    EXPECT_EQ(VD[0].Value, MD5Hash("vtable3"));
+    EXPECT_EQ(VD[1].Count, 1800U);
+    EXPECT_EQ(VD[1].Value, MD5Hash("vtable2"));
+  }
 }
 
 TEST_P(MaybeSparseInstrProfTest, get_max_function_count) {
@@ -1278,13 +1616,13 @@ TEST(SymtabTest, instr_prof_symtab_module_test) {
     std::string IRPGOName = getIRPGOFuncName(*F);
     auto IRPGOFuncName =
         ProfSymtab.getFuncOrVarName(IndexedInstrProf::ComputeHash(IRPGOName));
-    EXPECT_EQ(StringRef(IRPGOName), IRPGOFuncName);
-    EXPECT_EQ(StringRef(Funcs[I]), getParsedIRPGOName(IRPGOFuncName).second);
+    EXPECT_EQ(IRPGOName, IRPGOFuncName);
+    EXPECT_EQ(Funcs[I], getParsedIRPGOName(IRPGOFuncName).second);
     // Ensure we can still read this old record name.
     std::string PGOName = getPGOFuncName(*F);
     auto PGOFuncName =
         ProfSymtab.getFuncOrVarName(IndexedInstrProf::ComputeHash(PGOName));
-    EXPECT_EQ(StringRef(PGOName), PGOFuncName);
+    EXPECT_EQ(PGOName, PGOFuncName);
     EXPECT_THAT(PGOFuncName.str(), EndsWith(Funcs[I].str()));
   }
 }