1. use cl::list<std::string> for option type

2. Update `-icp-ignored-base-types` with one base type since this is
   sufficient

Author: mingmingl-llvm

llvm/include/llvm/Support/CommandLine.h

@@ -1208,26 +1208,6 @@ template <> class parser<char> : public basic_parser<char> {
   void anchor() override;
 };
 
-//--------------------------------------------------
-
-extern template class basic_parser<DenseSet<StringRef>>;
-
-template <>
-class parser<DenseSet<StringRef>> : public basic_parser<DenseSet<StringRef>> {
-public:
-  parser(Option &O) : basic_parser(O) {}
-
-  // Return true on error.
-  bool parse(Option &, StringRef, StringRef Arg, DenseSet<StringRef> &Val);
-
-  StringRef getValueName() const override { return "DenseSet<StringRef>"; }
-
-  void printOptionDiff(const Option &O, const DenseSet<StringRef> &V,
-                       OptVal Default, size_t GlobalWidth) const;
-
-  void anchor() override;
-};
-
 //--------------------------------------------------
 // This collection of wrappers is the intermediary between class opt and class
 // parser to handle all the template nastiness.

llvm/lib/Support/CommandLine.cpp

@@ -66,7 +66,6 @@ template class basic_parser<double>;
 template class basic_parser<float>;
 template class basic_parser<std::string>;
 template class basic_parser<char>;
-template class basic_parser<DenseSet<StringRef>>;
 
 template class opt<unsigned>;
 template class opt<int>;
@@ -94,7 +93,6 @@ void parser<double>::anchor() {}
 void parser<float>::anchor() {}
 void parser<std::string>::anchor() {}
 void parser<char>::anchor() {}
-void parser<DenseSet<StringRef>>::anchor() {}
 
 //===----------------------------------------------------------------------===//
 
@@ -2062,24 +2060,6 @@ bool parser<float>::parse(Option &O, StringRef ArgName, StringRef Arg,
   return false;
 }
 
-// parser<DenseSet<StringRef> implementation
-//
-void parser<DenseSet<StringRef>>::printOptionDiff(
-    const Option &O, const DenseSet<StringRef> &V,
-    OptionValue<DenseSet<StringRef>> D, size_t GlobalWidth) const {}
-
-bool parser<DenseSet<StringRef>>::parse(Option &O, StringRef ArgName,
-                                        StringRef Arg,
-                                        DenseSet<StringRef> &Val) {
-  SmallVector<StringRef> StrRefs;
-  llvm::SplitString(Arg, StrRefs, ",");
-  for (const StringRef StrRef : StrRefs)
-    if (!Val.insert(StrRef).second)
-      return O.error(Arg + " has duplicated strings!");
-
-  return false;
-}
-
 // generic_parser_base implementation
 //
 

llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp

@@ -132,13 +132,14 @@ static cl::opt<int> ICPMaxNumVTableLastCandidate(
     "icp-max-num-vtable-last-candidate", cl::init(1), cl::Hidden,
     cl::desc("The maximum number of vtable for the last candidate."));
 
-static cl::opt<DenseSet<StringRef>> ICPIgnoredBaseTypes(
-    "icp-ignored-base-types", cl::Hidden, cl::init(DenseSet<StringRef>()),
-    cl::desc("A comma-separated list of mangled vtable names. Classes "
-             "specified by the vtables and their derived ones will not be "
-             "vtable-ICP'ed. Useful when the profiled types and actual types "
-             "in the optimized binary could be different due to profiling "
-             "limitations."));
+static cl::list<std::string> ICPIgnoredBaseTypes(
+    "icp-ignored-base-types", cl::Hidden,
+    cl::desc(
+        "A list of mangled vtable names. Classes specified by the vtables "
+        "and their derived ones will not be vtable-ICP'ed. Useful when the "
+        "profiled types and actual types in the optimized binary could be "
+        "different due to profiling "
+        "limitations."));
 
 namespace {
 
@@ -324,6 +325,8 @@ class IndirectCallPromoter {
 
   OptimizationRemarkEmitter &ORE;
 
+  const DenseSet<StringRef> &IgnoredBaseTypes;
+
   // A struct that records the direct target and it's call count.
   struct PromotionCandidate {
     Function *const TargetFunction;
@@ -399,10 +402,12 @@ class IndirectCallPromoter {
       Function &Func, Module &M, InstrProfSymtab *Symtab, bool SamplePGO,
       const VirtualCallSiteTypeInfoMap &VirtualCSInfo,
       VTableAddressPointOffsetValMap &VTableAddressPointOffsetVal,
+      const DenseSet<StringRef> &IgnoredBaseTypes,
       OptimizationRemarkEmitter &ORE)
       : F(Func), M(M), Symtab(Symtab), SamplePGO(SamplePGO),
         VirtualCSInfo(VirtualCSInfo),
-        VTableAddressPointOffsetVal(VTableAddressPointOffsetVal), ORE(ORE) {}
+        VTableAddressPointOffsetVal(VTableAddressPointOffsetVal), ORE(ORE),
+        IgnoredBaseTypes(IgnoredBaseTypes) {}
   IndirectCallPromoter(const IndirectCallPromoter &) = delete;
   IndirectCallPromoter &operator=(const IndirectCallPromoter &) = delete;
 
@@ -859,24 +864,22 @@ bool IndirectCallPromoter::isProfitableToCompareVTables(
     LLVM_DEBUG(dbgs() << "\n");
 
     uint64_t CandidateVTableCount = 0;
-    SmallVector<MDNode *, 2> Types;
+
     for (auto &[GUID, Count] : VTableGUIDAndCounts) {
       CandidateVTableCount += Count;
       auto *VTableVar = Symtab->getGlobalVariable(GUID);
 
       assert(VTableVar &&
              "VTableVar must exist for GUID in VTableGUIDAndCounts");
 
-      Types.clear();
+      SmallVector<MDNode *, 2> Types;
       VTableVar->getMetadata(LLVMContext::MD_type, Types);
 
-      const DenseSet<StringRef> &VTableSet = ICPIgnoredBaseTypes.getValue();
       for (auto *Type : Types)
         if (auto *TypeId = dyn_cast<MDString>(Type->getOperand(1).get()))
-          if (VTableSet.contains(TypeId->getString().str())) {
-            LLVM_DEBUG(dbgs()
-                       << "    vtable profiles are known to be "
-                          "unrepresentative. Bail out vtable comparison.");
+          if (IgnoredBaseTypes.contains(TypeId->getString())) {
+            LLVM_DEBUG(dbgs() << "    vtable profiles should be ignored. Bail "
+                                 "out vtable comparison.");
             return false;
           }
     }
@@ -983,9 +986,15 @@ static bool promoteIndirectCalls(Module &M, ProfileSummaryInfo *PSI, bool InLTO,
   bool Changed = false;
   VirtualCallSiteTypeInfoMap VirtualCSInfo;
 
-  if (EnableVTableProfileUse)
+  DenseSet<StringRef> IgnoredBaseTypes;
+
+  if (EnableVTableProfileUse) {
     computeVirtualCallSiteTypeInfoMap(M, MAM, VirtualCSInfo);
 
+    for (StringRef Str : ICPIgnoredBaseTypes)
+      IgnoredBaseTypes.insert(Str);
+  }
+
   // VTableAddressPointOffsetVal stores the vtable address points. The vtable
   // address point of a given <vtable, address point offset> is static (doesn't
   // change after being computed once).
@@ -1004,7 +1013,8 @@ static bool promoteIndirectCalls(Module &M, ProfileSummaryInfo *PSI, bool InLTO,
     auto &ORE = FAM.getResult<OptimizationRemarkEmitterAnalysis>(F);
 
     IndirectCallPromoter CallPromoter(F, M, &Symtab, SamplePGO, VirtualCSInfo,
-                                      VTableAddressPointOffsetVal, ORE);
+                                      VTableAddressPointOffsetVal,
+                                      IgnoredBaseTypes, ORE);
     bool FuncChanged = CallPromoter.processFunction(PSI);
     if (ICPDUMPAFTER && FuncChanged) {
       LLVM_DEBUG(dbgs() << "\n== IR Dump After =="; F.print(dbgs()));

llvm/test/Transforms/PGOProfile/icp_vtable_cmp.ll

@@ -2,7 +2,7 @@
 
 ; RUN: opt < %s -passes='pgo-icall-prom' -pass-remarks=pgo-icall-prom -enable-vtable-profile-use -icp-max-num-vtable-last-candidate=2 -S 2>&1 | FileCheck %s --check-prefixes=VTABLE-COMMON,VTABLE-CMP
 ; RUN: opt < %s -passes='pgo-icall-prom' -pass-remarks=pgo-icall-prom -enable-vtable-profile-use -icp-max-num-vtable-last-candidate=1 -S 2>&1 | FileCheck %s --check-prefixes=VTABLE-COMMON,FUNC-CMP
-; RUN: opt < %s -passes='pgo-icall-prom' -pass-remarks=pgo-icall-prom -enable-vtable-profile-use -icp-max-num-vtable-last-candidate=1 -icp-ignored-base-types='Base1,Derived3' -S 2>&1 | FileCheck %s --check-prefixes=VTABLE-COMMON,FUNC-CMP
+; RUN: opt < %s -passes='pgo-icall-prom' -pass-remarks=pgo-icall-prom -enable-vtable-profile-use -icp-max-num-vtable-last-candidate=1 -icp-ignored-base-types='Base1' -S 2>&1 | FileCheck %s --check-prefixes=VTABLE-COMMON,FUNC-CMP
 
 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"