Revert "Add a new insert_as() method to DenseMap and use it for ConstantUniqueMap"

This reverts commit r260458.

It was backported on an internal branch and broke stage2 build. Since
this can lead to weird random crash I'm reverting upstream as well
while investigating.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 260605

1 files changed, 17 insertions, 23 deletions

diff --git a/llvm/lib/IR/ConstantsContext.h b/llvm/lib/IR/ConstantsContext.h
index e87e23128fc..a03279554c5 100644
--- a/llvm/lib/IR/ConstantsContext.h
+++ b/llvm/lib/IR/ConstantsContext.h
@@ -546,9 +546,6 @@ public:
   typedef typename ConstantInfo<ConstantClass>::TypeClass TypeClass;
   typedef std::pair<TypeClass *, ValType> LookupKey;
 
-  /// Key and hash together, so that we compute the hash only once and reuse it.
-  typedef std::pair<unsigned, LookupKey> LookupKeyHashed;
-
 private:
   struct MapInfo {
     typedef DenseMapInfo<ConstantClass *> ConstantClassInfo;
@@ -568,9 +565,6 @@ private:
     static unsigned getHashValue(const LookupKey &Val) {
       return hash_combine(Val.first, Val.second.getHash());
     }
-    static unsigned getHashValue(const LookupKeyHashed &Val) {
-      return Val.first;
-    }
     static bool isEqual(const LookupKey &LHS, const ConstantClass *RHS) {
       if (RHS == getEmptyKey() || RHS == getTombstoneKey())
         return false;
@@ -578,9 +572,6 @@ private:
         return false;
       return LHS.second == RHS;
     }
-    static bool isEqual(const LookupKeyHashed &LHS, const ConstantClass *RHS) {
-      return isEqual(LHS.second, RHS);
-    }
   };
 
 public:
@@ -598,12 +589,13 @@ public:
       // Asserts that use_empty().
       delete I.first;
   }
+
 private:
-  ConstantClass *create(TypeClass *Ty, ValType V, LookupKeyHashed &HashKey) {
+  ConstantClass *create(TypeClass *Ty, ValType V) {
     ConstantClass *Result = V.create(Ty);
 
     assert(Result->getType() == Ty && "Type specified is not correct!");
-    Map.insert_as(std::make_pair(Result, '\0'), HashKey);
+    insert(Result);
 
     return Result;
   }
@@ -611,15 +603,12 @@ private:
 public:
   /// Return the specified constant from the map, creating it if necessary.
   ConstantClass *getOrCreate(TypeClass *Ty, ValType V) {
-    LookupKey Key(Ty, V);
-    /// Hash once, and reuse it for the lookup and the insertion if needed.
-    LookupKeyHashed Lookup(MapInfo::getHashValue(Key), Key);
-
+    LookupKey Lookup(Ty, V);
     ConstantClass *Result = nullptr;
 
-    auto I = Map.find_as(Lookup);
+    auto I = find(Lookup);
     if (I == Map.end())
-      Result = create(Ty, V, Lookup);
+      Result = create(Ty, V);
     else
       Result = I->first;
     assert(Result && "Unexpected nullptr");
@@ -627,6 +616,14 @@ public:
     return Result;
   }
 
+  /// Find the constant by lookup key.
+  typename MapTy::iterator find(LookupKey Lookup) {
+    return Map.find_as(Lookup);
+  }
+
+  /// Insert the constant into its proper slot.
+  void insert(ConstantClass *CP) { Map[CP] = '\0'; }
+
   /// Remove this constant from the map
   void remove(ConstantClass *CP) {
     typename MapTy::iterator I = Map.find(CP);
@@ -639,11 +636,8 @@ public:
                                         ConstantClass *CP, Value *From,
                                         Constant *To, unsigned NumUpdated = 0,
                                         unsigned OperandNo = ~0u) {
-    LookupKey Key(CP->getType(), ValType(Operands, CP));
-    /// Hash once, and reuse it for the lookup and the insertion if needed.
-    LookupKeyHashed Lookup(MapInfo::getHashValue(Key), Key);
-
-    auto I = Map.find_as(Lookup);
+    LookupKey Lookup(CP->getType(), ValType(Operands, CP));
+    auto I = find(Lookup);
     if (I != Map.end())
       return I->first;
 
@@ -659,7 +653,7 @@ public:
         if (CP->getOperand(I) == From)
           CP->setOperand(I, To);
     }
-    Map.insert_as(std::make_pair(CP, '\0'), Lookup);
+    insert(CP);
     return nullptr;
   }