[ADT] Remove unused DenseMapInfo::getTombstoneKey by MaskRay · Pull Request #200959 · llvm/llvm-project

MaskRay · 2026-06-01T22:06:14Z

#200595 changed DenseMap to no longer create tombstone buckets, so
DenseMapInfo::getTombstoneKey() is never called. Remove dead
definitions and dead tombstone branches.

llvm#200595 changed DenseMap to no longer create tombstone buckets, so DenseMapInfo<T>::getTombstoneKey() is never called. Remove dead definitions and dead tombstone branches.

llvmorg-github-actions · 2026-06-01T22:07:18Z

@llvm/pr-subscribers-llvm-support

Author: Fangrui Song (MaskRay)

Changes

#200595 changed DenseMap to no longer create tombstone buckets, so
DenseMapInfo<T>::getTombstoneKey() is never called. Remove dead
definitions and dead tombstone branches.

Patch is 26.81 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/200959.diff

26 Files Affected:

(modified) llvm/include/llvm/ADT/APFixedPoint.h (-8)
(modified) llvm/include/llvm/ADT/APInt.h (-6)
(modified) llvm/include/llvm/ADT/APSInt.h (-4)
(modified) llvm/include/llvm/ADT/ArrayRef.h (-9)
(modified) llvm/include/llvm/ADT/BitVector.h (-13)
(modified) llvm/include/llvm/ADT/CachedHashString.h (+12-28)
(modified) llvm/include/llvm/ADT/DenseMapInfo.h (-32)
(modified) llvm/include/llvm/ADT/DenseMapInfoVariant.h (-5)
(modified) llvm/include/llvm/ADT/Hashing.h (-1)
(modified) llvm/include/llvm/ADT/ImmutableList.h (-4)
(modified) llvm/include/llvm/ADT/PointerEmbeddedInt.h (-1)
(modified) llvm/include/llvm/ADT/PointerIntPair.h (-6)
(modified) llvm/include/llvm/ADT/PointerSumType.h (-5)
(modified) llvm/include/llvm/ADT/PointerUnion.h (-4)
(modified) llvm/include/llvm/ADT/SmallBitVector.h (-13)
(modified) llvm/include/llvm/ADT/SmallVector.h (-4)
(modified) llvm/include/llvm/ADT/StringRef.h (-7)
(modified) llvm/include/llvm/Support/FileSystem/UniqueID.h (-6)
(modified) llvm/include/llvm/Support/TypeSize.h (-3)
(modified) llvm/include/llvm/Support/UniqueBBID.h (-5)
(modified) llvm/include/llvm/Support/VersionTuple.h (-3)
(modified) llvm/lib/Support/StringRef.cpp (+1-4)
(modified) llvm/unittests/ADT/DenseMapTest.cpp (-5)
(modified) llvm/unittests/ADT/DenseSetTest.cpp (-4)
(modified) llvm/unittests/ADT/MapVectorTest.cpp (-1)
(modified) llvm/unittests/Support/ReverseIterationTest.cpp (-5)

diff --git a/llvm/include/llvm/ADT/APFixedPoint.h b/llvm/include/llvm/ADT/APFixedPoint.h
index 0a47cd50516d4..790a5e775fb56 100644
--- a/llvm/include/llvm/ADT/APFixedPoint.h
+++ b/llvm/include/llvm/ADT/APFixedPoint.h
@@ -143,10 +143,6 @@ template <> struct DenseMapInfo<FixedPointSemantics> {
     return FixedPointSemantics(0, 0, false, false, false);
   }
 
-  static inline FixedPointSemantics getTombstoneKey() {
-    return FixedPointSemantics(0, 1, false, false, false);
-  }
-
   static unsigned getHashValue(const FixedPointSemantics &Val) {
     return hash_value(Val);
   }
@@ -323,10 +319,6 @@ template <> struct DenseMapInfo<APFixedPoint> {
     return APFixedPoint(DenseMapInfo<FixedPointSemantics>::getEmptyKey());
   }
 
-  static inline APFixedPoint getTombstoneKey() {
-    return APFixedPoint(DenseMapInfo<FixedPointSemantics>::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const APFixedPoint &Val) {
     return hash_value(Val);
   }
diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index e8d806cf78578..1a4788248e554 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -2533,12 +2533,6 @@ template <> struct DenseMapInfo<APInt, void> {
     return V;
   }
 
-  static inline APInt getTombstoneKey() {
-    APInt V(nullptr, 0);
-    V.U.VAL = ~1ULL;
-    return V;
-  }
-
   LLVM_ABI static unsigned getHashValue(const APInt &Key);
 
   static bool isEqual(const APInt &LHS, const APInt &RHS) {
diff --git a/llvm/include/llvm/ADT/APSInt.h b/llvm/include/llvm/ADT/APSInt.h
index aca0579b3e796..c5f8ad731bdb0 100644
--- a/llvm/include/llvm/ADT/APSInt.h
+++ b/llvm/include/llvm/ADT/APSInt.h
@@ -371,10 +371,6 @@ template <> struct DenseMapInfo<APSInt, void> {
     return APSInt(DenseMapInfo<APInt, void>::getEmptyKey());
   }
 
-  static inline APSInt getTombstoneKey() {
-    return APSInt(DenseMapInfo<APInt, void>::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const APSInt &Key) {
     return DenseMapInfo<APInt, void>::getHashValue(Key);
   }
diff --git a/llvm/include/llvm/ADT/ArrayRef.h b/llvm/include/llvm/ADT/ArrayRef.h
index cf2c6d85dc272..badac76affdc9 100644
--- a/llvm/include/llvm/ADT/ArrayRef.h
+++ b/llvm/include/llvm/ADT/ArrayRef.h
@@ -569,23 +569,14 @@ template <typename T> struct DenseMapInfo<ArrayRef<T>, void> {
                        size_t(0));
   }
 
-  static inline ArrayRef<T> getTombstoneKey() {
-    return ArrayRef<T>(reinterpret_cast<const T *>(~static_cast<uintptr_t>(1)),
-                       size_t(0));
-  }
-
   static unsigned getHashValue(ArrayRef<T> Val) {
     assert(Val.data() != getEmptyKey().data() && "Cannot hash the empty key!");
-    assert(Val.data() != getTombstoneKey().data() &&
-           "Cannot hash the tombstone key!");
     return (unsigned)(hash_value(Val));
   }
 
   static bool isEqual(ArrayRef<T> LHS, ArrayRef<T> RHS) {
     if (RHS.data() == getEmptyKey().data())
       return LHS.data() == getEmptyKey().data();
-    if (RHS.data() == getTombstoneKey().data())
-      return LHS.data() == getTombstoneKey().data();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/ADT/BitVector.h b/llvm/include/llvm/ADT/BitVector.h
index 48b75b045cfbf..72c8a84c15ecf 100644
--- a/llvm/include/llvm/ADT/BitVector.h
+++ b/llvm/include/llvm/ADT/BitVector.h
@@ -705,12 +705,6 @@ class BitVector {
     std::swap(Size, RHS.Size);
   }
 
-  void invalid() {
-    assert(!Size && Bits.empty());
-    Size = (unsigned)-1;
-  }
-  bool isInvalid() const { return Size == (unsigned)-1; }
-
   ArrayRef<BitWord> getData() const { return {Bits.data(), Bits.size()}; }
 
   //===--------------------------------------------------------------------===//
@@ -854,18 +848,11 @@ inline BitVector::size_type capacity_in_bytes(const BitVector &X) {
 
 template <> struct DenseMapInfo<BitVector> {
   static inline BitVector getEmptyKey() { return {}; }
-  static inline BitVector getTombstoneKey() {
-    BitVector V;
-    V.invalid();
-    return V;
-  }
   static unsigned getHashValue(const BitVector &V) {
     return DenseMapInfo<std::pair<BitVector::size_type, ArrayRef<uintptr_t>>>::
         getHashValue(std::make_pair(V.size(), V.getData()));
   }
   static bool isEqual(const BitVector &LHS, const BitVector &RHS) {
-    if (LHS.isInvalid() || RHS.isInvalid())
-      return LHS.isInvalid() == RHS.isInvalid();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/ADT/CachedHashString.h b/llvm/include/llvm/ADT/CachedHashString.h
index ebd40e3207156..cc26216176198 100644
--- a/llvm/include/llvm/ADT/CachedHashString.h
+++ b/llvm/include/llvm/ADT/CachedHashString.h
@@ -12,8 +12,8 @@
 /// their string data.
 ///
 /// Unlike std::string, CachedHashString can be used in DenseSet/DenseMap
-/// (because, unlike std::string, CachedHashString lets us have empty and
-/// tombstone values).
+/// (because, unlike std::string, CachedHashString lets us have an empty
+/// value).
 ///
 //===----------------------------------------------------------------------===//
 
@@ -51,12 +51,8 @@ template <> struct DenseMapInfo<CachedHashStringRef> {
   static CachedHashStringRef getEmptyKey() {
     return CachedHashStringRef(DenseMapInfo<StringRef>::getEmptyKey(), 0);
   }
-  static CachedHashStringRef getTombstoneKey() {
-    return CachedHashStringRef(DenseMapInfo<StringRef>::getTombstoneKey(), 1);
-  }
   static unsigned getHashValue(const CachedHashStringRef &S) {
     assert(!isEqual(S, getEmptyKey()) && "Cannot hash the empty key!");
-    assert(!isEqual(S, getTombstoneKey()) && "Cannot hash the tombstone key!");
     return S.hash();
   }
   static bool isEqual(const CachedHashStringRef &LHS,
@@ -77,19 +73,14 @@ class CachedHashString {
   uint32_t Hash;
 
   static char *getEmptyKeyPtr() { return DenseMapInfo<char *>::getEmptyKey(); }
-  static char *getTombstoneKeyPtr() {
-    return DenseMapInfo<char *>::getTombstoneKey();
-  }
 
-  bool isEmptyOrTombstone() const {
-    return P == getEmptyKeyPtr() || P == getTombstoneKeyPtr();
-  }
+  bool isEmpty() const { return P == getEmptyKeyPtr(); }
 
-  struct ConstructEmptyOrTombstoneTy {};
+  struct ConstructEmptyTy {};
 
-  CachedHashString(ConstructEmptyOrTombstoneTy, char *EmptyOrTombstonePtr)
-      : P(EmptyOrTombstonePtr), Size(0), Hash(0) {
-    assert(isEmptyOrTombstone());
+  CachedHashString(ConstructEmptyTy, char *EmptyKeyPtr)
+      : P(EmptyKeyPtr), Size(0), Hash(0) {
+    assert(isEmpty());
   }
 
   // TODO: Use small-string optimization to avoid allocating.
@@ -110,7 +101,7 @@ class CachedHashString {
   // keys, and we want this to be usable there.
   CachedHashString(const CachedHashString &Other)
       : Size(Other.Size), Hash(Other.Hash) {
-    if (Other.isEmptyOrTombstone()) {
+    if (Other.isEmpty()) {
       P = Other.P;
     } else {
       P = new char[Size];
@@ -129,7 +120,7 @@ class CachedHashString {
   }
 
   ~CachedHashString() {
-    if (!isEmptyOrTombstone())
+    if (!isEmpty())
       delete[] P;
   }
 
@@ -152,16 +143,11 @@ class CachedHashString {
 
 template <> struct DenseMapInfo<CachedHashString> {
   static CachedHashString getEmptyKey() {
-    return CachedHashString(CachedHashString::ConstructEmptyOrTombstoneTy(),
+    return CachedHashString(CachedHashString::ConstructEmptyTy(),
                             CachedHashString::getEmptyKeyPtr());
   }
-  static CachedHashString getTombstoneKey() {
-    return CachedHashString(CachedHashString::ConstructEmptyOrTombstoneTy(),
-                            CachedHashString::getTombstoneKeyPtr());
-  }
   static unsigned getHashValue(const CachedHashString &S) {
     assert(!isEqual(S, getEmptyKey()) && "Cannot hash the empty key!");
-    assert(!isEqual(S, getTombstoneKey()) && "Cannot hash the tombstone key!");
     return S.hash();
   }
   static bool isEqual(const CachedHashString &LHS,
@@ -170,11 +156,9 @@ template <> struct DenseMapInfo<CachedHashString> {
       return false;
     if (LHS.P == CachedHashString::getEmptyKeyPtr())
       return RHS.P == CachedHashString::getEmptyKeyPtr();
-    if (LHS.P == CachedHashString::getTombstoneKeyPtr())
-      return RHS.P == CachedHashString::getTombstoneKeyPtr();
 
-    // This is safe because if RHS.P is the empty or tombstone key, it will have
-    // length 0, so we'll never dereference its pointer.
+    // This is safe because if RHS.P is the empty key, it will have length 0, so
+    // we'll never dereference its pointer.
     return LHS.val() == RHS.val();
   }
 };
diff --git a/llvm/include/llvm/ADT/DenseMapInfo.h b/llvm/include/llvm/ADT/DenseMapInfo.h
index 832c12fc6482c..e8e21e4a15e66 100644
--- a/llvm/include/llvm/ADT/DenseMapInfo.h
+++ b/llvm/include/llvm/ADT/DenseMapInfo.h
@@ -53,7 +53,6 @@ inline unsigned combineHashValue(unsigned a, unsigned b) {
 template<typename T, typename Enable = void>
 struct DenseMapInfo {
   // static constexpr T getEmptyKey();
-  // static constexpr T getTombstoneKey();
   // static unsigned getHashValue(const T &Val);
   // static bool isEqual(const T &LHS, const T &RHS);
 };
@@ -77,12 +76,6 @@ struct DenseMapInfo<T*> {
     return reinterpret_cast<T*>(Val);
   }
 
-  static constexpr T *getTombstoneKey() {
-    uintptr_t Val = static_cast<uintptr_t>(-2);
-    Val <<= Log2MaxAlign;
-    return reinterpret_cast<T*>(Val);
-  }
-
   static unsigned getHashValue(const T *PtrVal) {
     return densemap::detail::mix(reinterpret_cast<uintptr_t>(PtrVal));
   }
@@ -93,7 +86,6 @@ struct DenseMapInfo<T*> {
 // Provide DenseMapInfo for chars.
 template<> struct DenseMapInfo<char> {
   static constexpr char getEmptyKey() { return ~0; }
-  static constexpr char getTombstoneKey() { return ~0 - 1; }
   static unsigned getHashValue(const char& Val) { return Val * 37U; }
 
   static bool isEqual(const char &LHS, const char &RHS) {
@@ -112,13 +104,6 @@ struct DenseMapInfo<
     T, std::enable_if_t<std::is_integral_v<T> && !std::is_same_v<T, char>>> {
   static constexpr T getEmptyKey() { return std::numeric_limits<T>::max(); }
 
-  static constexpr T getTombstoneKey() {
-    if constexpr (std::is_unsigned_v<T> || std::is_same_v<T, long>)
-      return std::numeric_limits<T>::max() - 1;
-    else
-      return std::numeric_limits<T>::min();
-  }
-
   static unsigned getHashValue(const T &Val) {
     if constexpr (std::is_unsigned_v<T> && sizeof(T) > sizeof(unsigned))
       return densemap::detail::mix(Val);
@@ -141,10 +126,6 @@ struct DenseMapInfo<std::pair<T, U>> {
     return {FirstInfo::getEmptyKey(), SecondInfo::getEmptyKey()};
   }
 
-  static constexpr Pair getTombstoneKey() {
-    return {FirstInfo::getTombstoneKey(), SecondInfo::getTombstoneKey()};
-  }
-
   static unsigned getHashValue(const Pair& PairVal) {
     return detail::combineHashValue(FirstInfo::getHashValue(PairVal.first),
                                     SecondInfo::getHashValue(PairVal.second));
@@ -172,10 +153,6 @@ template <typename... Ts> struct DenseMapInfo<std::tuple<Ts...>> {
     return Tuple(DenseMapInfo<Ts>::getEmptyKey()...);
   }
 
-  static constexpr Tuple getTombstoneKey() {
-    return Tuple(DenseMapInfo<Ts>::getTombstoneKey()...);
-  }
-
   template <unsigned I> static unsigned getHashValueImpl(const Tuple &values) {
     if constexpr (I == sizeof...(Ts)) {
       return 0;
@@ -223,11 +200,6 @@ struct DenseMapInfo<Enum, std::enable_if_t<std::is_enum_v<Enum>>> {
     return V;
   }
 
-  static constexpr Enum getTombstoneKey() {
-    constexpr Enum V = static_cast<Enum>(Info::getTombstoneKey());
-    return V;
-  }
-
   static unsigned getHashValue(const Enum &Val) {
     return Info::getHashValue(static_cast<UnderlyingType>(Val));
   }
@@ -241,10 +213,6 @@ template <typename T> struct DenseMapInfo<std::optional<T>> {
 
   static constexpr Optional getEmptyKey() { return {Info::getEmptyKey()}; }
 
-  static constexpr Optional getTombstoneKey() {
-    return {Info::getTombstoneKey()};
-  }
-
   static unsigned getHashValue(const Optional &OptionalVal) {
     return detail::combineHashValue(
         OptionalVal.has_value(),
diff --git a/llvm/include/llvm/ADT/DenseMapInfoVariant.h b/llvm/include/llvm/ADT/DenseMapInfoVariant.h
index a97f9b9566c81..9729f2a300098 100644
--- a/llvm/include/llvm/ADT/DenseMapInfoVariant.h
+++ b/llvm/include/llvm/ADT/DenseMapInfoVariant.h
@@ -29,11 +29,6 @@ template <typename... Ts> struct DenseMapInfo<std::variant<Ts...>> {
     return Variant(std::in_place_index<0>, DenseMapInfo<FirstT>::getEmptyKey());
   }
 
-  static inline Variant getTombstoneKey() {
-    return Variant(std::in_place_index<0>,
-                   DenseMapInfo<FirstT>::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const Variant &Val) {
     return std::visit(
         [&Val](auto &&Alternative) {
diff --git a/llvm/include/llvm/ADT/Hashing.h b/llvm/include/llvm/ADT/Hashing.h
index 6d679d815a417..5565b09543233 100644
--- a/llvm/include/llvm/ADT/Hashing.h
+++ b/llvm/include/llvm/ADT/Hashing.h
@@ -392,7 +392,6 @@ template <typename T> hash_code hash_value(const std::optional<T> &arg) {
 
 template <> struct DenseMapInfo<hash_code, void> {
   static constexpr hash_code getEmptyKey() { return hash_code(-1); }
-  static constexpr hash_code getTombstoneKey() { return hash_code(-2); }
   static constexpr unsigned getHashValue(hash_code val) {
     return static_cast<unsigned>(size_t(val));
   }
diff --git a/llvm/include/llvm/ADT/ImmutableList.h b/llvm/include/llvm/ADT/ImmutableList.h
index c9c289ca4dfa1..ef3f8a21db470 100644
--- a/llvm/include/llvm/ADT/ImmutableList.h
+++ b/llvm/include/llvm/ADT/ImmutableList.h
@@ -224,10 +224,6 @@ template <typename T> struct DenseMapInfo<ImmutableList<T>, void> {
     return reinterpret_cast<ImmutableListImpl<T>*>(-1);
   }
 
-  static inline ImmutableList<T> getTombstoneKey() {
-    return reinterpret_cast<ImmutableListImpl<T>*>(-2);
-  }
-
   static unsigned getHashValue(ImmutableList<T> X) {
     uintptr_t PtrVal = reinterpret_cast<uintptr_t>(X.getInternalPointer());
     return (unsigned((uintptr_t)PtrVal) >> 4) ^
diff --git a/llvm/include/llvm/ADT/PointerEmbeddedInt.h b/llvm/include/llvm/ADT/PointerEmbeddedInt.h
index 04a2b7bff78e0..76b03a40a9e27 100644
--- a/llvm/include/llvm/ADT/PointerEmbeddedInt.h
+++ b/llvm/include/llvm/ADT/PointerEmbeddedInt.h
@@ -102,7 +102,6 @@ struct DenseMapInfo<PointerEmbeddedInt<IntT, Bits>> {
   using IntInfo = DenseMapInfo<IntT>;
 
   static inline T getEmptyKey() { return IntInfo::getEmptyKey(); }
-  static inline T getTombstoneKey() { return IntInfo::getTombstoneKey(); }
 
   static unsigned getHashValue(const T &Arg) {
     return IntInfo::getHashValue(Arg);
diff --git a/llvm/include/llvm/ADT/PointerIntPair.h b/llvm/include/llvm/ADT/PointerIntPair.h
index 75e3a58e7ca61..db6714ffcfe91 100644
--- a/llvm/include/llvm/ADT/PointerIntPair.h
+++ b/llvm/include/llvm/ADT/PointerIntPair.h
@@ -223,12 +223,6 @@ struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType>, void> {
     return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
   }
 
-  static Ty getTombstoneKey() {
-    uintptr_t Val = static_cast<uintptr_t>(-2);
-    Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
-    return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
-  }
-
   static unsigned getHashValue(Ty V) {
     uintptr_t IV = reinterpret_cast<uintptr_t>(V.getOpaqueValue());
     return unsigned(IV) ^ unsigned(IV >> 9);
diff --git a/llvm/include/llvm/ADT/PointerSumType.h b/llvm/include/llvm/ADT/PointerSumType.h
index c8e6cffd796a6..beaaf49a32b52 100644
--- a/llvm/include/llvm/ADT/PointerSumType.h
+++ b/llvm/include/llvm/ADT/PointerSumType.h
@@ -259,11 +259,6 @@ struct DenseMapInfo<PointerSumType<TagT, MemberTs...>> {
     return SumType::template create<SomeTag>(SomePointerInfo::getEmptyKey());
   }
 
-  static inline SumType getTombstoneKey() {
-    return SumType::template create<SomeTag>(
-        SomePointerInfo::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const SumType &Arg) {
     uintptr_t OpaqueValue = Arg.getOpaqueValue();
     return DenseMapInfo<uintptr_t>::getHashValue(OpaqueValue);
diff --git a/llvm/include/llvm/ADT/PointerUnion.h b/llvm/include/llvm/ADT/PointerUnion.h
index 52cb12168f9b7..15565ee3ff51a 100644
--- a/llvm/include/llvm/ADT/PointerUnion.h
+++ b/llvm/include/llvm/ADT/PointerUnion.h
@@ -428,10 +428,6 @@ template <typename... PTs> struct DenseMapInfo<PointerUnion<PTs...>> {
 
   static inline Union getEmptyKey() { return Union(FirstInfo::getEmptyKey()); }
 
-  static inline Union getTombstoneKey() {
-    return Union(FirstInfo::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const Union &UnionVal) {
     auto Key = reinterpret_cast<uintptr_t>(UnionVal.getOpaqueValue());
     return DenseMapInfo<uintptr_t>::getHashValue(Key);
diff --git a/llvm/include/llvm/ADT/SmallBitVector.h b/llvm/include/llvm/ADT/SmallBitVector.h
index 978dc3f073031..78049cbb44da5 100644
--- a/llvm/include/llvm/ADT/SmallBitVector.h
+++ b/llvm/include/llvm/ADT/SmallBitVector.h
@@ -683,12 +683,6 @@ class SmallBitVector {
       getPointer()->clearBitsNotInMask(Mask, MaskWords);
   }
 
-  void invalid() {
-    assert(empty());
-    X = (uintptr_t)-1;
-  }
-  bool isInvalid() const { return X == (uintptr_t)-1; }
-
   ArrayRef<uintptr_t> getData(uintptr_t &Store) const {
     if (!isSmall())
       return getPointer()->getData();
@@ -735,11 +729,6 @@ operator^(const SmallBitVector &LHS, const SmallBitVector &RHS) {
 
 template <> struct DenseMapInfo<SmallBitVector> {
   static inline SmallBitVector getEmptyKey() { return SmallBitVector(); }
-  static inline SmallBitVector getTombstoneKey() {
-    SmallBitVector V;
-    V.invalid();
-    return V;
-  }
   static unsigned getHashValue(const SmallBitVector &V) {
     uintptr_t Store;
     return DenseMapInfo<
@@ -747,8 +736,6 @@ template <> struct DenseMapInfo<SmallBitVector> {
         getHashValue(std::make_pair(V.size(), V.getData(Store)));
   }
   static bool isEqual(const SmallBitVector &LHS, const SmallBitVector &RHS) {
-    if (LHS.isInvalid() || RHS.isInvalid())
-      return LHS.isInvalid() == RHS.isInvalid();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/ADT/SmallVector.h b/llvm/include/llvm/ADT/SmallVector.h
index 3d655daea471b..7e375792df4c0 100644
--- a/llvm/include/llvm/ADT/SmallVector.h
+++ b/llvm/include/llvm/ADT/SmallVector.h
@@ -1353,10 +1353,6 @@ template <typename T, unsigned N> struct DenseMapInfo<llvm::SmallVector<T, N>> {
     return {DenseMapInfo<T>::getEmptyKey()};
   }
 
-  static SmallVector<T, N> getTombstoneKey() {
-    return {DenseMapInfo<T>::getTombstoneKey()};
-  }
-
   static unsigned getHashValue(const SmallVector<T, N> &V) {
     return static_cast<unsigned>(hash_combine_range(V));
   }
diff --git a/llvm/include/llvm/ADT/StringRef.h b/llvm/include/llvm/ADT/StringRef.h
index 5421224e6a1d3..f15e120451638 100644
--- a/llvm/include/llvm/ADT/StringRef.h
+++ b/llvm/include/llvm/ADT/StringRef.h
@@ -956,18 +956,11 @@ template <> struct DenseMapInfo<StringRef, void> {
                      0);
   }
 
-  static inline StringRef getTombstoneKey() {
-    return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)),
-                     0);
-  }
-
   LLVM_ABI static unsigned getHashValue(StringRef Val);
 
   static bool isEqual(StringRef LHS, StringRef RHS) {
     if (RHS.data() == getEmptyKey().data())
       return LHS.data() == getEmptyKey().data();
-    if (RHS.data() == getTombstoneKey().data())
-      return LHS.data() == getTombstoneKey().data();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/Support/FileSystem/UniqueID.h b/llvm/include/llvm/Support/FileSystem/UniqueID.h
index 0d5367236e8dc..3bfd8b7405505 100644
--- a/llvm/include/llvm/Support/FileSystem/UniqueID.h
+++ b/llvm/include/llvm/Support/FileSystem/UniqueID.h
@@ -58,12 +58,6 @@ template <> struct DenseMapInfo<llvm::sys::fs::UniqueID> {
     return {EmptyKey.first, EmptyKey.second};
   }
 
-  static inline llvm::sys::fs::UniqueID getTombstoneKey() {
-    auto TombstoneKey =
-        DenseMapInfo<std::pair<uint64_t, uint64_t>>::getTombstoneKey();
-    return {TombstoneKey.first, TombstoneKey.second};
-  }
-
   static hash_code getHashValue(const llvm::sys::fs::UniqueID &Tag) {
     return hash_value(std::make_pair(Tag.getDevice(), Tag.getFile()));
   }
diff --git a/llvm/include/llvm/Support/TypeSize.h b/llvm/include/llvm/Support/TypeSize.h
index 421d6613bfafc..c60bae2872f92 100644
--- a/llvm/include/llvm/Support/TypeSize.h
+++ b/llvm/include/llvm/Suppo...
[truncated]

llvmorg-github-actions · 2026-06-01T22:07:19Z

@llvm/pr-subscribers-llvm-adt

Author: Fangrui Song (MaskRay)

Changes

#200595 changed DenseMap to no longer create tombstone buckets, so
DenseMapInfo<T>::getTombstoneKey() is never called. Remove dead
definitions and dead tombstone branches.

Patch is 26.81 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/200959.diff

26 Files Affected:

(modified) llvm/include/llvm/ADT/APFixedPoint.h (-8)
(modified) llvm/include/llvm/ADT/APInt.h (-6)
(modified) llvm/include/llvm/ADT/APSInt.h (-4)
(modified) llvm/include/llvm/ADT/ArrayRef.h (-9)
(modified) llvm/include/llvm/ADT/BitVector.h (-13)
(modified) llvm/include/llvm/ADT/CachedHashString.h (+12-28)
(modified) llvm/include/llvm/ADT/DenseMapInfo.h (-32)
(modified) llvm/include/llvm/ADT/DenseMapInfoVariant.h (-5)
(modified) llvm/include/llvm/ADT/Hashing.h (-1)
(modified) llvm/include/llvm/ADT/ImmutableList.h (-4)
(modified) llvm/include/llvm/ADT/PointerEmbeddedInt.h (-1)
(modified) llvm/include/llvm/ADT/PointerIntPair.h (-6)
(modified) llvm/include/llvm/ADT/PointerSumType.h (-5)
(modified) llvm/include/llvm/ADT/PointerUnion.h (-4)
(modified) llvm/include/llvm/ADT/SmallBitVector.h (-13)
(modified) llvm/include/llvm/ADT/SmallVector.h (-4)
(modified) llvm/include/llvm/ADT/StringRef.h (-7)
(modified) llvm/include/llvm/Support/FileSystem/UniqueID.h (-6)
(modified) llvm/include/llvm/Support/TypeSize.h (-3)
(modified) llvm/include/llvm/Support/UniqueBBID.h (-5)
(modified) llvm/include/llvm/Support/VersionTuple.h (-3)
(modified) llvm/lib/Support/StringRef.cpp (+1-4)
(modified) llvm/unittests/ADT/DenseMapTest.cpp (-5)
(modified) llvm/unittests/ADT/DenseSetTest.cpp (-4)
(modified) llvm/unittests/ADT/MapVectorTest.cpp (-1)
(modified) llvm/unittests/Support/ReverseIterationTest.cpp (-5)

diff --git a/llvm/include/llvm/ADT/APFixedPoint.h b/llvm/include/llvm/ADT/APFixedPoint.h
index 0a47cd50516d4..790a5e775fb56 100644
--- a/llvm/include/llvm/ADT/APFixedPoint.h
+++ b/llvm/include/llvm/ADT/APFixedPoint.h
@@ -143,10 +143,6 @@ template <> struct DenseMapInfo<FixedPointSemantics> {
     return FixedPointSemantics(0, 0, false, false, false);
   }
 
-  static inline FixedPointSemantics getTombstoneKey() {
-    return FixedPointSemantics(0, 1, false, false, false);
-  }
-
   static unsigned getHashValue(const FixedPointSemantics &Val) {
     return hash_value(Val);
   }
@@ -323,10 +319,6 @@ template <> struct DenseMapInfo<APFixedPoint> {
     return APFixedPoint(DenseMapInfo<FixedPointSemantics>::getEmptyKey());
   }
 
-  static inline APFixedPoint getTombstoneKey() {
-    return APFixedPoint(DenseMapInfo<FixedPointSemantics>::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const APFixedPoint &Val) {
     return hash_value(Val);
   }
diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index e8d806cf78578..1a4788248e554 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -2533,12 +2533,6 @@ template <> struct DenseMapInfo<APInt, void> {
     return V;
   }
 
-  static inline APInt getTombstoneKey() {
-    APInt V(nullptr, 0);
-    V.U.VAL = ~1ULL;
-    return V;
-  }
-
   LLVM_ABI static unsigned getHashValue(const APInt &Key);
 
   static bool isEqual(const APInt &LHS, const APInt &RHS) {
diff --git a/llvm/include/llvm/ADT/APSInt.h b/llvm/include/llvm/ADT/APSInt.h
index aca0579b3e796..c5f8ad731bdb0 100644
--- a/llvm/include/llvm/ADT/APSInt.h
+++ b/llvm/include/llvm/ADT/APSInt.h
@@ -371,10 +371,6 @@ template <> struct DenseMapInfo<APSInt, void> {
     return APSInt(DenseMapInfo<APInt, void>::getEmptyKey());
   }
 
-  static inline APSInt getTombstoneKey() {
-    return APSInt(DenseMapInfo<APInt, void>::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const APSInt &Key) {
     return DenseMapInfo<APInt, void>::getHashValue(Key);
   }
diff --git a/llvm/include/llvm/ADT/ArrayRef.h b/llvm/include/llvm/ADT/ArrayRef.h
index cf2c6d85dc272..badac76affdc9 100644
--- a/llvm/include/llvm/ADT/ArrayRef.h
+++ b/llvm/include/llvm/ADT/ArrayRef.h
@@ -569,23 +569,14 @@ template <typename T> struct DenseMapInfo<ArrayRef<T>, void> {
                        size_t(0));
   }
 
-  static inline ArrayRef<T> getTombstoneKey() {
-    return ArrayRef<T>(reinterpret_cast<const T *>(~static_cast<uintptr_t>(1)),
-                       size_t(0));
-  }
-
   static unsigned getHashValue(ArrayRef<T> Val) {
     assert(Val.data() != getEmptyKey().data() && "Cannot hash the empty key!");
-    assert(Val.data() != getTombstoneKey().data() &&
-           "Cannot hash the tombstone key!");
     return (unsigned)(hash_value(Val));
   }
 
   static bool isEqual(ArrayRef<T> LHS, ArrayRef<T> RHS) {
     if (RHS.data() == getEmptyKey().data())
       return LHS.data() == getEmptyKey().data();
-    if (RHS.data() == getTombstoneKey().data())
-      return LHS.data() == getTombstoneKey().data();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/ADT/BitVector.h b/llvm/include/llvm/ADT/BitVector.h
index 48b75b045cfbf..72c8a84c15ecf 100644
--- a/llvm/include/llvm/ADT/BitVector.h
+++ b/llvm/include/llvm/ADT/BitVector.h
@@ -705,12 +705,6 @@ class BitVector {
     std::swap(Size, RHS.Size);
   }
 
-  void invalid() {
-    assert(!Size && Bits.empty());
-    Size = (unsigned)-1;
-  }
-  bool isInvalid() const { return Size == (unsigned)-1; }
-
   ArrayRef<BitWord> getData() const { return {Bits.data(), Bits.size()}; }
 
   //===--------------------------------------------------------------------===//
@@ -854,18 +848,11 @@ inline BitVector::size_type capacity_in_bytes(const BitVector &X) {
 
 template <> struct DenseMapInfo<BitVector> {
   static inline BitVector getEmptyKey() { return {}; }
-  static inline BitVector getTombstoneKey() {
-    BitVector V;
-    V.invalid();
-    return V;
-  }
   static unsigned getHashValue(const BitVector &V) {
     return DenseMapInfo<std::pair<BitVector::size_type, ArrayRef<uintptr_t>>>::
         getHashValue(std::make_pair(V.size(), V.getData()));
   }
   static bool isEqual(const BitVector &LHS, const BitVector &RHS) {
-    if (LHS.isInvalid() || RHS.isInvalid())
-      return LHS.isInvalid() == RHS.isInvalid();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/ADT/CachedHashString.h b/llvm/include/llvm/ADT/CachedHashString.h
index ebd40e3207156..cc26216176198 100644
--- a/llvm/include/llvm/ADT/CachedHashString.h
+++ b/llvm/include/llvm/ADT/CachedHashString.h
@@ -12,8 +12,8 @@
 /// their string data.
 ///
 /// Unlike std::string, CachedHashString can be used in DenseSet/DenseMap
-/// (because, unlike std::string, CachedHashString lets us have empty and
-/// tombstone values).
+/// (because, unlike std::string, CachedHashString lets us have an empty
+/// value).
 ///
 //===----------------------------------------------------------------------===//
 
@@ -51,12 +51,8 @@ template <> struct DenseMapInfo<CachedHashStringRef> {
   static CachedHashStringRef getEmptyKey() {
     return CachedHashStringRef(DenseMapInfo<StringRef>::getEmptyKey(), 0);
   }
-  static CachedHashStringRef getTombstoneKey() {
-    return CachedHashStringRef(DenseMapInfo<StringRef>::getTombstoneKey(), 1);
-  }
   static unsigned getHashValue(const CachedHashStringRef &S) {
     assert(!isEqual(S, getEmptyKey()) && "Cannot hash the empty key!");
-    assert(!isEqual(S, getTombstoneKey()) && "Cannot hash the tombstone key!");
     return S.hash();
   }
   static bool isEqual(const CachedHashStringRef &LHS,
@@ -77,19 +73,14 @@ class CachedHashString {
   uint32_t Hash;
 
   static char *getEmptyKeyPtr() { return DenseMapInfo<char *>::getEmptyKey(); }
-  static char *getTombstoneKeyPtr() {
-    return DenseMapInfo<char *>::getTombstoneKey();
-  }
 
-  bool isEmptyOrTombstone() const {
-    return P == getEmptyKeyPtr() || P == getTombstoneKeyPtr();
-  }
+  bool isEmpty() const { return P == getEmptyKeyPtr(); }
 
-  struct ConstructEmptyOrTombstoneTy {};
+  struct ConstructEmptyTy {};
 
-  CachedHashString(ConstructEmptyOrTombstoneTy, char *EmptyOrTombstonePtr)
-      : P(EmptyOrTombstonePtr), Size(0), Hash(0) {
-    assert(isEmptyOrTombstone());
+  CachedHashString(ConstructEmptyTy, char *EmptyKeyPtr)
+      : P(EmptyKeyPtr), Size(0), Hash(0) {
+    assert(isEmpty());
   }
 
   // TODO: Use small-string optimization to avoid allocating.
@@ -110,7 +101,7 @@ class CachedHashString {
   // keys, and we want this to be usable there.
   CachedHashString(const CachedHashString &Other)
       : Size(Other.Size), Hash(Other.Hash) {
-    if (Other.isEmptyOrTombstone()) {
+    if (Other.isEmpty()) {
       P = Other.P;
     } else {
       P = new char[Size];
@@ -129,7 +120,7 @@ class CachedHashString {
   }
 
   ~CachedHashString() {
-    if (!isEmptyOrTombstone())
+    if (!isEmpty())
       delete[] P;
   }
 
@@ -152,16 +143,11 @@ class CachedHashString {
 
 template <> struct DenseMapInfo<CachedHashString> {
   static CachedHashString getEmptyKey() {
-    return CachedHashString(CachedHashString::ConstructEmptyOrTombstoneTy(),
+    return CachedHashString(CachedHashString::ConstructEmptyTy(),
                             CachedHashString::getEmptyKeyPtr());
   }
-  static CachedHashString getTombstoneKey() {
-    return CachedHashString(CachedHashString::ConstructEmptyOrTombstoneTy(),
-                            CachedHashString::getTombstoneKeyPtr());
-  }
   static unsigned getHashValue(const CachedHashString &S) {
     assert(!isEqual(S, getEmptyKey()) && "Cannot hash the empty key!");
-    assert(!isEqual(S, getTombstoneKey()) && "Cannot hash the tombstone key!");
     return S.hash();
   }
   static bool isEqual(const CachedHashString &LHS,
@@ -170,11 +156,9 @@ template <> struct DenseMapInfo<CachedHashString> {
       return false;
     if (LHS.P == CachedHashString::getEmptyKeyPtr())
       return RHS.P == CachedHashString::getEmptyKeyPtr();
-    if (LHS.P == CachedHashString::getTombstoneKeyPtr())
-      return RHS.P == CachedHashString::getTombstoneKeyPtr();
 
-    // This is safe because if RHS.P is the empty or tombstone key, it will have
-    // length 0, so we'll never dereference its pointer.
+    // This is safe because if RHS.P is the empty key, it will have length 0, so
+    // we'll never dereference its pointer.
     return LHS.val() == RHS.val();
   }
 };
diff --git a/llvm/include/llvm/ADT/DenseMapInfo.h b/llvm/include/llvm/ADT/DenseMapInfo.h
index 832c12fc6482c..e8e21e4a15e66 100644
--- a/llvm/include/llvm/ADT/DenseMapInfo.h
+++ b/llvm/include/llvm/ADT/DenseMapInfo.h
@@ -53,7 +53,6 @@ inline unsigned combineHashValue(unsigned a, unsigned b) {
 template<typename T, typename Enable = void>
 struct DenseMapInfo {
   // static constexpr T getEmptyKey();
-  // static constexpr T getTombstoneKey();
   // static unsigned getHashValue(const T &Val);
   // static bool isEqual(const T &LHS, const T &RHS);
 };
@@ -77,12 +76,6 @@ struct DenseMapInfo<T*> {
     return reinterpret_cast<T*>(Val);
   }
 
-  static constexpr T *getTombstoneKey() {
-    uintptr_t Val = static_cast<uintptr_t>(-2);
-    Val <<= Log2MaxAlign;
-    return reinterpret_cast<T*>(Val);
-  }
-
   static unsigned getHashValue(const T *PtrVal) {
     return densemap::detail::mix(reinterpret_cast<uintptr_t>(PtrVal));
   }
@@ -93,7 +86,6 @@ struct DenseMapInfo<T*> {
 // Provide DenseMapInfo for chars.
 template<> struct DenseMapInfo<char> {
   static constexpr char getEmptyKey() { return ~0; }
-  static constexpr char getTombstoneKey() { return ~0 - 1; }
   static unsigned getHashValue(const char& Val) { return Val * 37U; }
 
   static bool isEqual(const char &LHS, const char &RHS) {
@@ -112,13 +104,6 @@ struct DenseMapInfo<
     T, std::enable_if_t<std::is_integral_v<T> && !std::is_same_v<T, char>>> {
   static constexpr T getEmptyKey() { return std::numeric_limits<T>::max(); }
 
-  static constexpr T getTombstoneKey() {
-    if constexpr (std::is_unsigned_v<T> || std::is_same_v<T, long>)
-      return std::numeric_limits<T>::max() - 1;
-    else
-      return std::numeric_limits<T>::min();
-  }
-
   static unsigned getHashValue(const T &Val) {
     if constexpr (std::is_unsigned_v<T> && sizeof(T) > sizeof(unsigned))
       return densemap::detail::mix(Val);
@@ -141,10 +126,6 @@ struct DenseMapInfo<std::pair<T, U>> {
     return {FirstInfo::getEmptyKey(), SecondInfo::getEmptyKey()};
   }
 
-  static constexpr Pair getTombstoneKey() {
-    return {FirstInfo::getTombstoneKey(), SecondInfo::getTombstoneKey()};
-  }
-
   static unsigned getHashValue(const Pair& PairVal) {
     return detail::combineHashValue(FirstInfo::getHashValue(PairVal.first),
                                     SecondInfo::getHashValue(PairVal.second));
@@ -172,10 +153,6 @@ template <typename... Ts> struct DenseMapInfo<std::tuple<Ts...>> {
     return Tuple(DenseMapInfo<Ts>::getEmptyKey()...);
   }
 
-  static constexpr Tuple getTombstoneKey() {
-    return Tuple(DenseMapInfo<Ts>::getTombstoneKey()...);
-  }
-
   template <unsigned I> static unsigned getHashValueImpl(const Tuple &values) {
     if constexpr (I == sizeof...(Ts)) {
       return 0;
@@ -223,11 +200,6 @@ struct DenseMapInfo<Enum, std::enable_if_t<std::is_enum_v<Enum>>> {
     return V;
   }
 
-  static constexpr Enum getTombstoneKey() {
-    constexpr Enum V = static_cast<Enum>(Info::getTombstoneKey());
-    return V;
-  }
-
   static unsigned getHashValue(const Enum &Val) {
     return Info::getHashValue(static_cast<UnderlyingType>(Val));
   }
@@ -241,10 +213,6 @@ template <typename T> struct DenseMapInfo<std::optional<T>> {
 
   static constexpr Optional getEmptyKey() { return {Info::getEmptyKey()}; }
 
-  static constexpr Optional getTombstoneKey() {
-    return {Info::getTombstoneKey()};
-  }
-
   static unsigned getHashValue(const Optional &OptionalVal) {
     return detail::combineHashValue(
         OptionalVal.has_value(),
diff --git a/llvm/include/llvm/ADT/DenseMapInfoVariant.h b/llvm/include/llvm/ADT/DenseMapInfoVariant.h
index a97f9b9566c81..9729f2a300098 100644
--- a/llvm/include/llvm/ADT/DenseMapInfoVariant.h
+++ b/llvm/include/llvm/ADT/DenseMapInfoVariant.h
@@ -29,11 +29,6 @@ template <typename... Ts> struct DenseMapInfo<std::variant<Ts...>> {
     return Variant(std::in_place_index<0>, DenseMapInfo<FirstT>::getEmptyKey());
   }
 
-  static inline Variant getTombstoneKey() {
-    return Variant(std::in_place_index<0>,
-                   DenseMapInfo<FirstT>::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const Variant &Val) {
     return std::visit(
         [&Val](auto &&Alternative) {
diff --git a/llvm/include/llvm/ADT/Hashing.h b/llvm/include/llvm/ADT/Hashing.h
index 6d679d815a417..5565b09543233 100644
--- a/llvm/include/llvm/ADT/Hashing.h
+++ b/llvm/include/llvm/ADT/Hashing.h
@@ -392,7 +392,6 @@ template <typename T> hash_code hash_value(const std::optional<T> &arg) {
 
 template <> struct DenseMapInfo<hash_code, void> {
   static constexpr hash_code getEmptyKey() { return hash_code(-1); }
-  static constexpr hash_code getTombstoneKey() { return hash_code(-2); }
   static constexpr unsigned getHashValue(hash_code val) {
     return static_cast<unsigned>(size_t(val));
   }
diff --git a/llvm/include/llvm/ADT/ImmutableList.h b/llvm/include/llvm/ADT/ImmutableList.h
index c9c289ca4dfa1..ef3f8a21db470 100644
--- a/llvm/include/llvm/ADT/ImmutableList.h
+++ b/llvm/include/llvm/ADT/ImmutableList.h
@@ -224,10 +224,6 @@ template <typename T> struct DenseMapInfo<ImmutableList<T>, void> {
     return reinterpret_cast<ImmutableListImpl<T>*>(-1);
   }
 
-  static inline ImmutableList<T> getTombstoneKey() {
-    return reinterpret_cast<ImmutableListImpl<T>*>(-2);
-  }
-
   static unsigned getHashValue(ImmutableList<T> X) {
     uintptr_t PtrVal = reinterpret_cast<uintptr_t>(X.getInternalPointer());
     return (unsigned((uintptr_t)PtrVal) >> 4) ^
diff --git a/llvm/include/llvm/ADT/PointerEmbeddedInt.h b/llvm/include/llvm/ADT/PointerEmbeddedInt.h
index 04a2b7bff78e0..76b03a40a9e27 100644
--- a/llvm/include/llvm/ADT/PointerEmbeddedInt.h
+++ b/llvm/include/llvm/ADT/PointerEmbeddedInt.h
@@ -102,7 +102,6 @@ struct DenseMapInfo<PointerEmbeddedInt<IntT, Bits>> {
   using IntInfo = DenseMapInfo<IntT>;
 
   static inline T getEmptyKey() { return IntInfo::getEmptyKey(); }
-  static inline T getTombstoneKey() { return IntInfo::getTombstoneKey(); }
 
   static unsigned getHashValue(const T &Arg) {
     return IntInfo::getHashValue(Arg);
diff --git a/llvm/include/llvm/ADT/PointerIntPair.h b/llvm/include/llvm/ADT/PointerIntPair.h
index 75e3a58e7ca61..db6714ffcfe91 100644
--- a/llvm/include/llvm/ADT/PointerIntPair.h
+++ b/llvm/include/llvm/ADT/PointerIntPair.h
@@ -223,12 +223,6 @@ struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType>, void> {
     return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
   }
 
-  static Ty getTombstoneKey() {
-    uintptr_t Val = static_cast<uintptr_t>(-2);
-    Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
-    return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
-  }
-
   static unsigned getHashValue(Ty V) {
     uintptr_t IV = reinterpret_cast<uintptr_t>(V.getOpaqueValue());
     return unsigned(IV) ^ unsigned(IV >> 9);
diff --git a/llvm/include/llvm/ADT/PointerSumType.h b/llvm/include/llvm/ADT/PointerSumType.h
index c8e6cffd796a6..beaaf49a32b52 100644
--- a/llvm/include/llvm/ADT/PointerSumType.h
+++ b/llvm/include/llvm/ADT/PointerSumType.h
@@ -259,11 +259,6 @@ struct DenseMapInfo<PointerSumType<TagT, MemberTs...>> {
     return SumType::template create<SomeTag>(SomePointerInfo::getEmptyKey());
   }
 
-  static inline SumType getTombstoneKey() {
-    return SumType::template create<SomeTag>(
-        SomePointerInfo::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const SumType &Arg) {
     uintptr_t OpaqueValue = Arg.getOpaqueValue();
     return DenseMapInfo<uintptr_t>::getHashValue(OpaqueValue);
diff --git a/llvm/include/llvm/ADT/PointerUnion.h b/llvm/include/llvm/ADT/PointerUnion.h
index 52cb12168f9b7..15565ee3ff51a 100644
--- a/llvm/include/llvm/ADT/PointerUnion.h
+++ b/llvm/include/llvm/ADT/PointerUnion.h
@@ -428,10 +428,6 @@ template <typename... PTs> struct DenseMapInfo<PointerUnion<PTs...>> {
 
   static inline Union getEmptyKey() { return Union(FirstInfo::getEmptyKey()); }
 
-  static inline Union getTombstoneKey() {
-    return Union(FirstInfo::getTombstoneKey());
-  }
-
   static unsigned getHashValue(const Union &UnionVal) {
     auto Key = reinterpret_cast<uintptr_t>(UnionVal.getOpaqueValue());
     return DenseMapInfo<uintptr_t>::getHashValue(Key);
diff --git a/llvm/include/llvm/ADT/SmallBitVector.h b/llvm/include/llvm/ADT/SmallBitVector.h
index 978dc3f073031..78049cbb44da5 100644
--- a/llvm/include/llvm/ADT/SmallBitVector.h
+++ b/llvm/include/llvm/ADT/SmallBitVector.h
@@ -683,12 +683,6 @@ class SmallBitVector {
       getPointer()->clearBitsNotInMask(Mask, MaskWords);
   }
 
-  void invalid() {
-    assert(empty());
-    X = (uintptr_t)-1;
-  }
-  bool isInvalid() const { return X == (uintptr_t)-1; }
-
   ArrayRef<uintptr_t> getData(uintptr_t &Store) const {
     if (!isSmall())
       return getPointer()->getData();
@@ -735,11 +729,6 @@ operator^(const SmallBitVector &LHS, const SmallBitVector &RHS) {
 
 template <> struct DenseMapInfo<SmallBitVector> {
   static inline SmallBitVector getEmptyKey() { return SmallBitVector(); }
-  static inline SmallBitVector getTombstoneKey() {
-    SmallBitVector V;
-    V.invalid();
-    return V;
-  }
   static unsigned getHashValue(const SmallBitVector &V) {
     uintptr_t Store;
     return DenseMapInfo<
@@ -747,8 +736,6 @@ template <> struct DenseMapInfo<SmallBitVector> {
         getHashValue(std::make_pair(V.size(), V.getData(Store)));
   }
   static bool isEqual(const SmallBitVector &LHS, const SmallBitVector &RHS) {
-    if (LHS.isInvalid() || RHS.isInvalid())
-      return LHS.isInvalid() == RHS.isInvalid();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/ADT/SmallVector.h b/llvm/include/llvm/ADT/SmallVector.h
index 3d655daea471b..7e375792df4c0 100644
--- a/llvm/include/llvm/ADT/SmallVector.h
+++ b/llvm/include/llvm/ADT/SmallVector.h
@@ -1353,10 +1353,6 @@ template <typename T, unsigned N> struct DenseMapInfo<llvm::SmallVector<T, N>> {
     return {DenseMapInfo<T>::getEmptyKey()};
   }
 
-  static SmallVector<T, N> getTombstoneKey() {
-    return {DenseMapInfo<T>::getTombstoneKey()};
-  }
-
   static unsigned getHashValue(const SmallVector<T, N> &V) {
     return static_cast<unsigned>(hash_combine_range(V));
   }
diff --git a/llvm/include/llvm/ADT/StringRef.h b/llvm/include/llvm/ADT/StringRef.h
index 5421224e6a1d3..f15e120451638 100644
--- a/llvm/include/llvm/ADT/StringRef.h
+++ b/llvm/include/llvm/ADT/StringRef.h
@@ -956,18 +956,11 @@ template <> struct DenseMapInfo<StringRef, void> {
                      0);
   }
 
-  static inline StringRef getTombstoneKey() {
-    return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)),
-                     0);
-  }
-
   LLVM_ABI static unsigned getHashValue(StringRef Val);
 
   static bool isEqual(StringRef LHS, StringRef RHS) {
     if (RHS.data() == getEmptyKey().data())
       return LHS.data() == getEmptyKey().data();
-    if (RHS.data() == getTombstoneKey().data())
-      return LHS.data() == getTombstoneKey().data();
     return LHS == RHS;
   }
 };
diff --git a/llvm/include/llvm/Support/FileSystem/UniqueID.h b/llvm/include/llvm/Support/FileSystem/UniqueID.h
index 0d5367236e8dc..3bfd8b7405505 100644
--- a/llvm/include/llvm/Support/FileSystem/UniqueID.h
+++ b/llvm/include/llvm/Support/FileSystem/UniqueID.h
@@ -58,12 +58,6 @@ template <> struct DenseMapInfo<llvm::sys::fs::UniqueID> {
     return {EmptyKey.first, EmptyKey.second};
   }
 
-  static inline llvm::sys::fs::UniqueID getTombstoneKey() {
-    auto TombstoneKey =
-        DenseMapInfo<std::pair<uint64_t, uint64_t>>::getTombstoneKey();
-    return {TombstoneKey.first, TombstoneKey.second};
-  }
-
   static hash_code getHashValue(const llvm::sys::fs::UniqueID &Tag) {
     return hash_value(std::make_pair(Tag.getDevice(), Tag.getFile()));
   }
diff --git a/llvm/include/llvm/Support/TypeSize.h b/llvm/include/llvm/Support/TypeSize.h
index 421d6613bfafc..c60bae2872f92 100644
--- a/llvm/include/llvm/Support/TypeSize.h
+++ b/llvm/include/llvm/Suppo...
[truncated]

aengelke

LGTM if CI passes.

github-actions · 2026-06-02T13:36:26Z

🐧 Linux x64 Test Results

196104 tests passed
5296 tests skipped

✅ The build succeeded and all tests passed.

llvm#200595 changed DenseMap to no longer create tombstone buckets, so DenseMapInfo<T>::getTombstoneKey() is never called. Remove dead definitions and dead tombstone branches.

[ADT] Remove unused DenseMapInfo::getTombstoneKey

b1d3f84

llvm#200595 changed DenseMap to no longer create tombstone buckets, so DenseMapInfo<T>::getTombstoneKey() is never called. Remove dead definitions and dead tombstone branches.

MaskRay requested a review from aengelke June 1, 2026 22:06

llvmorg-github-actions Bot added llvm:support llvm:adt labels Jun 1, 2026

rebase

f7203f2

aengelke approved these changes Jun 2, 2026

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MaskRay merged commit 836bf56 into llvm:main Jun 2, 2026
13 of 14 checks passed

MaskRay mentioned this pull request Jun 2, 2026

[llvm] Remove unused DenseMapInfo::getTombstoneKey #200638

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MaskRay deleted the pr/drop-tombstone-llvm-adt branch June 5, 2026 05:29

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[ADT] Remove unused DenseMapInfo::getTombstoneKey#200959

[ADT] Remove unused DenseMapInfo::getTombstoneKey#200959
MaskRay merged 2 commits into
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MaskRay:pr/drop-tombstone-llvm-adt

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MaskRay commented Jun 1, 2026

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github-actions Bot commented Jun 2, 2026 •

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