4 files changed, 4 insertions, 83 deletions

diff --git a/llvm/lib/Fuzzer/FuzzerDriver.cpp b/llvm/lib/Fuzzer/FuzzerDriver.cpp
index 8bbafd3a43a..c5de16b1251 100644
--- a/llvm/lib/Fuzzer/FuzzerDriver.cpp
+++ b/llvm/lib/Fuzzer/FuzzerDriver.cpp
@@ -530,14 +530,10 @@ int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
   if (Flags.merge) {
     if (Options.MaxLen == 0)
       F->SetMaxInputLen(kMaxSaneLen);
-    if (TPC.UsingTracePcGuard()) {
-      if (Flags.merge_control_file)
-        F->CrashResistantMergeInternalStep(Flags.merge_control_file);
-      else
-        F->CrashResistantMerge(Args, *Inputs);
-    } else {
-      F->Merge(*Inputs);
-    }
+    if (Flags.merge_control_file)
+      F->CrashResistantMergeInternalStep(Flags.merge_control_file);
+    else
+      F->CrashResistantMerge(Args, *Inputs);
     exit(0);
   }
 
diff --git a/llvm/lib/Fuzzer/FuzzerInternal.h b/llvm/lib/Fuzzer/FuzzerInternal.h
index 798ee641cb6..347228ebc42 100644
--- a/llvm/lib/Fuzzer/FuzzerInternal.h
+++ b/llvm/lib/Fuzzer/FuzzerInternal.h
@@ -72,8 +72,6 @@ public:
   void CrashResistantMerge(const std::vector<std::string> &Args,
                            const std::vector<std::string> &Corpora);
   void CrashResistantMergeInternalStep(const std::string &ControlFilePath);
-  // Returns a subset of 'Extra' that adds coverage to 'Initial'.
-  UnitVector FindExtraUnits(const UnitVector &Initial, const UnitVector &Extra);
   MutationDispatcher &GetMD() { return MD; }
   void PrintFinalStats();
   void SetMaxInputLen(size_t MaxInputLen);
diff --git a/llvm/lib/Fuzzer/FuzzerLoop.cpp b/llvm/lib/Fuzzer/FuzzerLoop.cpp
index f4a2929a39f..bed28d84e6a 100644
--- a/llvm/lib/Fuzzer/FuzzerLoop.cpp
+++ b/llvm/lib/Fuzzer/FuzzerLoop.cpp
@@ -535,76 +535,6 @@ void Fuzzer::ReportNewCoverage(InputInfo *II, const Unit &U) {
   TPC.PrintNewPCs();
 }
 
-// Finds minimal number of units in 'Extra' that add coverage to 'Initial'.
-// We do it by actually executing the units, sometimes more than once,
-// because we may be using different coverage-like signals and the only
-// common thing between them is that we can say "this unit found new stuff".
-UnitVector Fuzzer::FindExtraUnits(const UnitVector &Initial,
-                                  const UnitVector &Extra) {
-  UnitVector Res = Extra;
-  UnitVector Tmp;
-  size_t OldSize = Res.size();
-  for (int Iter = 0; Iter < 10; Iter++) {
-    ShuffleCorpus(&Res);
-    TPC.ResetMaps();
-    Corpus.ResetFeatureSet();
-
-    for (auto &U : Initial) {
-      TPC.ResetMaps();
-      RunOne(U);
-    }
-
-    Tmp.clear();
-    for (auto &U : Res) {
-      TPC.ResetMaps();
-      if (RunOne(U))
-        Tmp.push_back(U);
-    }
-
-    char Stat[7] = "MIN   ";
-    Stat[3] = '0' + Iter;
-    PrintStats(Stat, "\n", Tmp.size());
-
-    size_t NewSize = Tmp.size();
-    assert(NewSize <= OldSize);
-    Res.swap(Tmp);
-
-    if (NewSize + 5 >= OldSize)
-      break;
-    OldSize = NewSize;
-  }
-  return Res;
-}
-
-void Fuzzer::Merge(const std::vector<std::string> &Corpora) {
-  if (Corpora.size() <= 1) {
-    Printf("Merge requires two or more corpus dirs\n");
-    return;
-  }
-  InMergeMode = true;
-  std::vector<std::string> ExtraCorpora(Corpora.begin() + 1, Corpora.end());
-
-  assert(MaxInputLen > 0);
-  UnitVector Initial, Extra;
-  ReadDirToVectorOfUnits(Corpora[0].c_str(), &Initial, nullptr, MaxInputLen,
-                         true);
-  for (auto &C : ExtraCorpora)
-    ReadDirToVectorOfUnits(C.c_str(), &Extra, nullptr, MaxInputLen, true);
-
-  if (!Initial.empty()) {
-    Printf("=== Minimizing the initial corpus of %zd units\n", Initial.size());
-    Initial = FindExtraUnits({}, Initial);
-  }
-
-  Printf("=== Merging extra %zd units\n", Extra.size());
-  auto Res = FindExtraUnits(Initial, Extra);
-
-  for (auto &U: Res)
-    WriteToOutputCorpus(U);
-
-  Printf("=== Merge: written %zd units\n", Res.size());
-}
-
 // Tries detecting a memory leak on the particular input that we have just
 // executed before calling this function.
 void Fuzzer::TryDetectingAMemoryLeak(const uint8_t *Data, size_t Size,
diff --git a/llvm/lib/Fuzzer/FuzzerTracePC.h b/llvm/lib/Fuzzer/FuzzerTracePC.h
index 05d03e960c9..1fbd0158b1d 100644
--- a/llvm/lib/Fuzzer/FuzzerTracePC.h
+++ b/llvm/lib/Fuzzer/FuzzerTracePC.h
@@ -75,8 +75,6 @@ class TracePC {
   void AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
                          size_t n, bool StopAtZero);
 
-  bool UsingTracePcGuard() const {return NumModules; }
-
   TableOfRecentCompares<uint32_t, 32> TORC4;
   TableOfRecentCompares<uint64_t, 32> TORC8;
   TableOfRecentCompares<Word, 32> TORCW;
@@ -112,7 +110,6 @@ private:
 
 template <class Callback>
 size_t TracePC::CollectFeatures(Callback CB) const {
-  if (!UsingTracePcGuard()) return 0;
   size_t Res = 0;
   const size_t Step = 8;
   uint8_t *Counters = this->Counters();