Remove isPod() from DenseMapInfo, splitting it out to its own

isPodLike type trait.  This is a generally useful type trait for
more than just DenseMap, and we really care about whether something
acts like a pod, not whether it really is a pod.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91421 91177308-0d34-0410-b5e6-96231b3b80d8

21 files changed, 115 insertions, 79 deletions

diff --git a/include/llvm/ADT/DenseMap.h b/include/llvm/ADT/DenseMap.h
index 83299478e9..8b62f2d8c8 100644
--- a/include/llvm/ADT/DenseMap.h
+++ b/include/llvm/ADT/DenseMap.h
@@ -217,7 +217,8 @@ public:
 
 private:
   void CopyFrom(const DenseMap& other) {
-    if (NumBuckets != 0 && (!KeyInfoT::isPod() || !ValueInfoT::isPod())) {
+    if (NumBuckets != 0 &&
+        (!isPodLike<KeyInfoT>::value || !isPodLike<ValueInfoT>::value)) {
       const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
       for (BucketT *P = Buckets, *E = Buckets+NumBuckets; P != E; ++P) {
         if (!KeyInfoT::isEqual(P->first, EmptyKey) &&
@@ -239,7 +240,7 @@ private:
     Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT) *
                                                  other.NumBuckets));
 
-    if (KeyInfoT::isPod() && ValueInfoT::isPod())
+    if (isPodLike<KeyInfoT>::value && isPodLike<ValueInfoT>::value)
       memcpy(Buckets, other.Buckets, other.NumBuckets * sizeof(BucketT));
     else
       for (size_t i = 0; i < other.NumBuckets; ++i) {
diff --git a/include/llvm/ADT/DenseMapInfo.h b/include/llvm/ADT/DenseMapInfo.h
index 2f241c514a..6b494ef5d0 100644
--- a/include/llvm/ADT/DenseMapInfo.h
+++ b/include/llvm/ADT/DenseMapInfo.h
@@ -15,7 +15,7 @@
 #define LLVM_ADT_DENSEMAPINFO_H
 
 #include "llvm/Support/PointerLikeTypeTraits.h"
-#include <utility>
+#include "llvm/Support/type_traits.h"
 
 namespace llvm {
 
@@ -25,7 +25,6 @@ struct DenseMapInfo {
   //static inline T getTombstoneKey();
   //static unsigned getHashValue(const T &Val);
   //static bool isEqual(const T &LHS, const T &RHS);
-  //static bool isPod()
 };
 
 // Provide DenseMapInfo for all pointers.
@@ -46,7 +45,6 @@ struct DenseMapInfo<T*> {
            (unsigned((uintptr_t)PtrVal) >> 9);
   }
   static bool isEqual(const T *LHS, const T *RHS) { return LHS == RHS; }
-  static bool isPod() { return true; }
 };
 
 // Provide DenseMapInfo for chars.
@@ -54,7 +52,6 @@ template<> struct DenseMapInfo<char> {
   static inline char getEmptyKey() { return ~0; }
   static inline char getTombstoneKey() { return ~0 - 1; }
   static unsigned getHashValue(const char& Val) { return Val * 37; }
-  static bool isPod() { return true; }
   static bool isEqual(const char &LHS, const char &RHS) {
     return LHS == RHS;
   }
@@ -65,7 +62,6 @@ template<> struct DenseMapInfo<unsigned> {
   static inline unsigned getEmptyKey() { return ~0; }
   static inline unsigned getTombstoneKey() { return ~0U - 1; }
   static unsigned getHashValue(const unsigned& Val) { return Val * 37; }
-  static bool isPod() { return true; }
   static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
     return LHS == RHS;
   }
@@ -78,7 +74,6 @@ template<> struct DenseMapInfo<unsigned long> {
   static unsigned getHashValue(const unsigned long& Val) {
     return (unsigned)(Val * 37UL);
   }
-  static bool isPod() { return true; }
   static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
     return LHS == RHS;
   }
@@ -91,7 +86,6 @@ template<> struct DenseMapInfo<unsigned long long> {
   static unsigned getHashValue(const unsigned long long& Val) {
     return (unsigned)(Val * 37ULL);
   }
-  static bool isPod() { return true; }
   static bool isEqual(const unsigned long long& LHS,
                       const unsigned long long& RHS) {
     return LHS == RHS;
@@ -127,7 +121,6 @@ struct DenseMapInfo<std::pair<T, U> > {
     return (unsigned)key;
   }
   static bool isEqual(const Pair& LHS, const Pair& RHS) { return LHS == RHS; }
-  static bool isPod() { return FirstInfo::isPod() && SecondInfo::isPod(); }
 };
 
 } // end namespace llvm
diff --git a/include/llvm/ADT/ImmutableList.h b/include/llvm/ADT/ImmutableList.h
index 5f8cb57f1c..7757c08770 100644
--- a/include/llvm/ADT/ImmutableList.h
+++ b/include/llvm/ADT/ImmutableList.h
@@ -211,9 +211,12 @@ template<typename T> struct DenseMapInfo<ImmutableList<T> > {
   static bool isEqual(ImmutableList<T> X1, ImmutableList<T> X2) {
     return X1 == X2;
   }
-  static bool isPod() { return true; }
 };
 
+template <typename T> struct isPodLike;
+template <typename T>
+struct isPodLike<ImmutableList<T> > { static const bool value = true; };
+
 } // end llvm namespace
 
 #endif
diff --git a/include/llvm/ADT/PointerIntPair.h b/include/llvm/ADT/PointerIntPair.h
index 73ba3c7293..64f4a7cee4 100644
--- a/include/llvm/ADT/PointerIntPair.h
+++ b/include/llvm/ADT/PointerIntPair.h
@@ -106,6 +106,12 @@ public:
   bool operator>=(const PointerIntPair &RHS) const {return Value >= RHS.Value;}
 };
 
+template <typename T> struct isPodLike;
+template<typename PointerTy, unsigned IntBits, typename IntType>
+struct isPodLike<PointerIntPair<PointerTy, IntBits, IntType> > {
+   static const bool value = true;
+};
+  
 // Provide specialization of DenseMapInfo for PointerIntPair.
 template<typename PointerTy, unsigned IntBits, typename IntType>
 struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType> > {
@@ -125,7 +131,6 @@ struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType> > {
     return unsigned(IV) ^ unsigned(IV >> 9);
   }
   static bool isEqual(const Ty &LHS, const Ty &RHS) { return LHS == RHS; }
-  static bool isPod() { return true; }
 };
 
 // Teach SmallPtrSet that PointerIntPair is "basically a pointer".
diff --git a/include/llvm/ADT/ValueMap.h b/include/llvm/ADT/ValueMap.h
index b043c389fd..6f57fe8399 100644
--- a/include/llvm/ADT/ValueMap.h
+++ b/include/llvm/ADT/ValueMap.h
@@ -250,6 +250,12 @@ public:
   }
 };
 
+  
+template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
+struct isPodLike<ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> > {
+  static const bool value = true;
+};
+
 template<typename KeyT, typename ValueT, typename Config, typename ValueInfoT>
 struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> > {
   typedef ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> VH;
@@ -267,7 +273,6 @@ struct DenseMapInfo<ValueMapCallbackVH<KeyT, ValueT, Config, ValueInfoT> > {
   static bool isEqual(const VH &LHS, const VH &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() { return false; }
 };
 
 
diff --git a/include/llvm/Analysis/AliasSetTracker.h b/include/llvm/Analysis/AliasSetTracker.h
index 42a377e141..09f12ad281 100644
--- a/include/llvm/Analysis/AliasSetTracker.h
+++ b/include/llvm/Analysis/AliasSetTracker.h
@@ -259,11 +259,9 @@ class AliasSetTracker {
     ASTCallbackVH(Value *V, AliasSetTracker *AST = 0);
     ASTCallbackVH &operator=(Value *V);
   };
-  /// ASTCallbackVHDenseMapInfo - Traits to tell DenseMap that ASTCallbackVH
-  /// is not a POD (it needs its destructor called).
-  struct ASTCallbackVHDenseMapInfo : public DenseMapInfo<Value *> {
-    static bool isPod() { return false; }
-  };
+  /// ASTCallbackVHDenseMapInfo - Traits to tell DenseMap that tell us how to
+  /// compare and hash the value handle.
+  struct ASTCallbackVHDenseMapInfo : public DenseMapInfo<Value *> {};
 
   AliasAnalysis &AA;
   ilist<AliasSet> AliasSets;
diff --git a/include/llvm/Bitcode/Deserialize.h b/include/llvm/Bitcode/Deserialize.h
index 90a51417d1..3266038a3d 100644
--- a/include/llvm/Bitcode/Deserialize.h
+++ b/include/llvm/Bitcode/Deserialize.h
@@ -25,53 +25,52 @@
 
 namespace llvm {
 
+struct BPNode {
+  BPNode* Next;
+  uintptr_t& PtrRef;
+  
+  BPNode(BPNode* n, uintptr_t& pref)
+  : Next(n), PtrRef(pref) {
+    PtrRef = 0;
+  }
+};
+
+struct BPEntry {
+  union { BPNode* Head; void* Ptr; };
+  BPEntry() : Head(NULL) {}
+  void SetPtr(BPNode*& FreeList, void* P);
+};
+
+class BPKey {
+  unsigned Raw;
+public:
+  BPKey(SerializedPtrID PtrId) : Raw(PtrId << 1) { assert (PtrId > 0); }
+  BPKey(unsigned code, unsigned) : Raw(code) {}
+  
+  void MarkFinal() { Raw |= 0x1; }
+  bool hasFinalPtr() const { return Raw & 0x1 ? true : false; }
+  SerializedPtrID getID() const { return Raw >> 1; }
+  
+  static inline BPKey getEmptyKey() { return BPKey(0,0); }
+  static inline BPKey getTombstoneKey() { return BPKey(1,0); }
+  static inline unsigned getHashValue(const BPKey& K) { return K.Raw & ~0x1; }
+  
+  static bool isEqual(const BPKey& K1, const BPKey& K2) {
+    return (K1.Raw ^ K2.Raw) & ~0x1 ? false : true;
+  }
+};
+  
+template <>
+struct isPodLike<BPKey> { static const bool value = true; };
+template <>
+struct isPodLike<BPEntry> { static const bool value = true; };
+  
 class Deserializer {
 
   //===----------------------------------------------------------===//
   // Internal type definitions.
   //===----------------------------------------------------------===//
 
-  struct BPNode {
-    BPNode* Next;
-    uintptr_t& PtrRef;
-
-    BPNode(BPNode* n, uintptr_t& pref)
-      : Next(n), PtrRef(pref) {
-        PtrRef = 0;
-      }
-  };
-
-  struct BPEntry {
-    union { BPNode* Head; void* Ptr; };
-
-    BPEntry() : Head(NULL) {}
-
-    static inline bool isPod() { return true; }
-
-    void SetPtr(BPNode*& FreeList, void* P);
-  };
-
-  class BPKey {
-    unsigned Raw;
-
-  public:
-    BPKey(SerializedPtrID PtrId) : Raw(PtrId << 1) { assert (PtrId > 0); }
-    BPKey(unsigned code, unsigned) : Raw(code) {}
-
-    void MarkFinal() { Raw |= 0x1; }
-    bool hasFinalPtr() const { return Raw & 0x1 ? true : false; }
-    SerializedPtrID getID() const { return Raw >> 1; }
-
-    static inline BPKey getEmptyKey() { return BPKey(0,0); }
-    static inline BPKey getTombstoneKey() { return BPKey(1,0); }
-    static inline unsigned getHashValue(const BPKey& K) { return K.Raw & ~0x1; }
-
-    static bool isEqual(const BPKey& K1, const BPKey& K2) {
-      return (K1.Raw ^ K2.Raw) & ~0x1 ? false : true;
-    }
-
-    static bool isPod() { return true; }
-  };
 
   typedef llvm::DenseMap<BPKey,BPEntry,BPKey,BPEntry> MapTy;
 
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index 580986a181..571db47797 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -891,8 +891,9 @@ template<> struct DenseMapInfo<SDValue> {
   static bool isEqual(const SDValue &LHS, const SDValue &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() { return true; }
 };
+template <> struct isPodLike<SDValue> { static const bool value = true; };
+
 
 /// simplify_type specializations - Allow casting operators to work directly on
 /// SDValues as if they were SDNode*'s.
diff --git a/include/llvm/CodeGen/SlotIndexes.h b/include/llvm/CodeGen/SlotIndexes.h
index 65d85fcb31..0cc00070e3 100644
--- a/include/llvm/CodeGen/SlotIndexes.h
+++ b/include/llvm/CodeGen/SlotIndexes.h
@@ -329,6 +329,7 @@ namespace llvm {
   };
 
   /// DenseMapInfo specialization for SlotIndex.
+  /// TODO: Not a POD?
   template <>
   struct DenseMapInfo<SlotIndex> {
     static inline SlotIndex getEmptyKey() {
@@ -343,7 +344,6 @@ namespace llvm {
     static inline bool isEqual(const SlotIndex &LHS, const SlotIndex &RHS) {
       return (LHS == RHS);
     }
-    static inline bool isPod() { return false; }
   };
 
   inline raw_ostream& operator<<(raw_ostream &os, SlotIndex li) {
diff --git a/include/llvm/Support/DebugLoc.h b/include/llvm/Support/DebugLoc.h
index 362390f628..6814f63d9e 100644
--- a/include/llvm/Support/DebugLoc.h
+++ b/include/llvm/Support/DebugLoc.h
@@ -66,7 +66,7 @@ namespace llvm {
   };
 
   // Specialize DenseMapInfo for DebugLocTuple.
-  template<>  struct DenseMapInfo<DebugLocTuple> {
+  template<> struct DenseMapInfo<DebugLocTuple> {
     static inline DebugLocTuple getEmptyKey() {
       return DebugLocTuple(0, 0, ~0U, ~0U);
     }
@@ -85,9 +85,9 @@ namespace llvm {
              LHS.Line         == RHS.Line &&
              LHS.Col          == RHS.Col;
     }
-
-    static bool isPod() { return true; }
   };
+  template <> struct isPodLike<DebugLocTuple> {static const bool value = true;};
+
 
   /// DebugLocTracker - This class tracks debug location information.
   ///
diff --git a/include/llvm/Support/ValueHandle.h b/include/llvm/Support/ValueHandle.h
index a9872a7be1..82c3caeb3a 100644
--- a/include/llvm/Support/ValueHandle.h
+++ b/include/llvm/Support/ValueHandle.h
@@ -254,15 +254,18 @@ struct DenseMapInfo<AssertingVH<T> > {
   static bool isEqual(const AssertingVH<T> &LHS, const AssertingVH<T> &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() {
+};
+  
+template <typename T>
+struct isPodLike<AssertingVH<T> > {
 #ifdef NDEBUG
-    return true;
+  static const bool value = true;
 #else
-    return false;
+  static const bool value = false;
 #endif
-  }
 };
 
+
 /// TrackingVH - This is a value handle that tracks a Value (or Value subclass),
 /// even across RAUW operations.
 ///
diff --git a/include/llvm/Support/type_traits.h b/include/llvm/Support/type_traits.h
index ce916b5fcc..1f3f1e4f89 100644
--- a/include/llvm/Support/type_traits.h
+++ b/include/llvm/Support/type_traits.h
@@ -17,6 +17,8 @@
 #ifndef LLVM_SUPPORT_TYPE_TRAITS_H
 #define LLVM_SUPPORT_TYPE_TRAITS_H
 
+#include <utility>
+
 // This is actually the conforming implementation which works with abstract
 // classes.  However, enough compilers have trouble with it that most will use
 // the one in boost/type_traits/object_traits.hpp. This implementation actually
@@ -24,6 +26,33 @@
 
 namespace llvm {
 
+/// isPodLike - This is a type trait that is used to determine whether a given
+/// type can be copied around with memcpy instead of running ctors etc.
+template <typename T>
+struct isPodLike {
+  static const bool value = false;  
+};
+  
+// pointers are all pod-like.
+template <typename T>
+struct isPodLike<T*> { static const bool value = true; };
+
+// builtin types are pod-like as well.
+// There is probably a much better way to do this.
+template <> struct isPodLike<char> { static const bool value = true; };
+template <> struct isPodLike<unsigned> { static const bool value = true; };
+template <> struct isPodLike<unsigned long> { static const bool value = true; };
+template <> struct isPodLike<unsigned long long> {
+  static const bool value = true;
+};
+  
+  
+// pairs are pod-like if their elements are.
+template<typename T, typename U>
+struct isPodLike<std::pair<T, U> > {
+  static const bool value = isPodLike<T>::value & isPodLike<U>::value;
+};
+  
 namespace dont_use
 {
     // These two functions should never be used. They are helpers to
diff --git a/lib/Analysis/IPA/Andersens.cpp b/lib/Analysis/IPA/Andersens.cpp
index e12db81744..4d5b312c0b 100644
--- a/lib/Analysis/IPA/Andersens.cpp
+++ b/lib/Analysis/IPA/Andersens.cpp
@@ -121,8 +121,6 @@ namespace {
 
       return *LHS == *RHS;
     }
-
-    static bool isPod() { return true; }
   };
 
   class Andersens : public ModulePass, public AliasAnalysis,
diff --git a/lib/Bitcode/Reader/Deserialize.cpp b/lib/Bitcode/Reader/Deserialize.cpp
index 67607efae0..b8e720a880 100644
--- a/lib/Bitcode/Reader/Deserialize.cpp
+++ b/lib/Bitcode/Reader/Deserialize.cpp
@@ -413,7 +413,7 @@ uintptr_t Deserializer::ReadInternalRefPtr() {
   return GetFinalPtr(E);
 }
 
-void Deserializer::BPEntry::SetPtr(BPNode*& FreeList, void* P) {
+void BPEntry::SetPtr(BPNode*& FreeList, void* P) {
   BPNode* Last = NULL;
   
   for (BPNode* N = Head; N != NULL; N=N->Next) {
diff --git a/lib/CodeGen/AsmPrinter/DwarfException.h b/lib/CodeGen/AsmPrinter/DwarfException.h
index aff1665e9b..aa01c5b803 100644
--- a/lib/CodeGen/AsmPrinter/DwarfException.h
+++ b/lib/CodeGen/AsmPrinter/DwarfException.h
@@ -119,7 +119,6 @@ class DwarfException : public Dwarf {
     static inline unsigned getTombstoneKey() { return -2U; }
     static unsigned getHashValue(const unsigned &Key) { return Key; }
     static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
-    static bool isPod() { return true; }
   };
 
   /// PadRange - Structure holding a try-range and the associated landing pad.
diff --git a/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp b/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp
index f2b28ad326..01934860fb 100644
--- a/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp
@@ -175,7 +175,6 @@ struct KeyInfo {
   static inline unsigned getTombstoneKey() { return -2U; }
   static unsigned getHashValue(const unsigned &Key) { return Key; }
   static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
-  static bool isPod() { return true; }
 };
 
 /// ActionEntry - Structure describing an entry in the actions table.
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index dcc9dd4f49..222792bc75 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -190,8 +190,11 @@ template <> struct DenseMapInfo<Expression> {
   static bool isEqual(const Expression &LHS, const Expression &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() { return true; }
 };
+  
+template <>
+struct isPodLike<Expression> { static const bool value = true; };
+
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 2b4b66b500..b9c536fe1e 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11200,8 +11200,9 @@ namespace llvm {
       return LHS.PN == RHS.PN && LHS.Shift == RHS.Shift &&
              LHS.Width == RHS.Width;
     }
-    static bool isPod() { return true; }
   };
+  template <>
+  struct isPodLike<LoweredPHIRecord> { static const bool value = true; };
 }
 
 
diff --git a/lib/Transforms/Scalar/SCCVN.cpp b/lib/Transforms/Scalar/SCCVN.cpp
index db87874107..dbc82e1301 100644
--- a/lib/Transforms/Scalar/SCCVN.cpp
+++ b/lib/Transforms/Scalar/SCCVN.cpp
@@ -154,8 +154,10 @@ template <> struct DenseMapInfo<Expression> {
   static bool isEqual(const Expression &LHS, const Expression &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() { return true; }
 };
+template <>
+struct isPodLike<Expression> { static const bool value = true; };
+
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Transforms/Utils/PromoteMemoryToRegister.cpp b/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
index 438ac43bcb..846e432a7d 100644
--- a/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
+++ b/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
@@ -55,7 +55,6 @@ struct DenseMapInfo<std::pair<BasicBlock*, unsigned> > {
   static bool isEqual(const EltTy &LHS, const EltTy &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() { return true; }
 };
 }
 
diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index 1c3244ba4d..8a2378ec7c 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -62,7 +62,6 @@ struct DenseMapAPIntKeyInfo {
   static bool isEqual(const KeyTy &LHS, const KeyTy &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() { return false; }
 };
 
 struct DenseMapAPFloatKeyInfo {
@@ -89,7 +88,6 @@ struct DenseMapAPFloatKeyInfo {
   static bool isEqual(const KeyTy &LHS, const KeyTy &RHS) {
     return LHS == RHS;
   }
-  static bool isPod() { return false; }
 };
 
 class LLVMContextImpl {