1 files changed, 23 insertions, 17 deletions

diff --git a/llvm/lib/IR/ConstantsContext.h b/llvm/lib/IR/ConstantsContext.h
index a03279554c5..e87e23128fc 100644
--- a/llvm/lib/IR/ConstantsContext.h
+++ b/llvm/lib/IR/ConstantsContext.h
@@ -546,6 +546,9 @@ 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;
@@ -565,6 +568,9 @@ 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;
@@ -572,6 +578,9 @@ private:
         return false;
       return LHS.second == RHS;
     }
+    static bool isEqual(const LookupKeyHashed &LHS, const ConstantClass *RHS) {
+      return isEqual(LHS.second, RHS);
+    }
   };
 
 public:
@@ -589,13 +598,12 @@ public:
       // Asserts that use_empty().
       delete I.first;
   }
-
 private:
-  ConstantClass *create(TypeClass *Ty, ValType V) {
+  ConstantClass *create(TypeClass *Ty, ValType V, LookupKeyHashed &HashKey) {
     ConstantClass *Result = V.create(Ty);
 
     assert(Result->getType() == Ty && "Type specified is not correct!");
-    insert(Result);
+    Map.insert_as(std::make_pair(Result, '\0'), HashKey);
 
     return Result;
   }
@@ -603,12 +611,15 @@ private:
 public:
   /// Return the specified constant from the map, creating it if necessary.
   ConstantClass *getOrCreate(TypeClass *Ty, ValType V) {
-    LookupKey Lookup(Ty, V);
+    LookupKey Key(Ty, V);
+    /// Hash once, and reuse it for the lookup and the insertion if needed.
+    LookupKeyHashed Lookup(MapInfo::getHashValue(Key), Key);
+
     ConstantClass *Result = nullptr;
 
-    auto I = find(Lookup);
+    auto I = Map.find_as(Lookup);
     if (I == Map.end())
-      Result = create(Ty, V);
+      Result = create(Ty, V, Lookup);
     else
       Result = I->first;
     assert(Result && "Unexpected nullptr");
@@ -616,14 +627,6 @@ 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);
@@ -636,8 +639,11 @@ public:
                                         ConstantClass *CP, Value *From,
                                         Constant *To, unsigned NumUpdated = 0,
                                         unsigned OperandNo = ~0u) {
-    LookupKey Lookup(CP->getType(), ValType(Operands, CP));
-    auto I = find(Lookup);
+    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);
     if (I != Map.end())
       return I->first;
 
@@ -653,7 +659,7 @@ public:
         if (CP->getOperand(I) == From)
           CP->setOperand(I, To);
     }
-    insert(CP);
+    Map.insert_as(std::make_pair(CP, '\0'), Lookup);
     return nullptr;
   }